The tissue bank at the Instituto Nacional de Investigaciones Nucleares: ISO 9001:2000 certification of its quality management system.

PubMed

Martínez-Pardo, María Esther; Mariano-Magaña, David

2007-01-01

Tissue banking is a complex operation concerned with the organisation and coordination of all the steps, that is, from donor selection up to storage and distribution of the final products for therapeutic, diagnostic, instruction and research purposes. An appropriate quality framework should be established in order to cover all the specific methodology as well as the general aspects of quality management, such as research and development, design, instruction and training, specific documentation, traceability, corrective action, client satisfaction, and the like. Such a framework can be obtained by developing a quality management system (QMS) in accordance with a suitable international standard: ISO 9001:2000. This paper presents the implementation process of the tissue bank QMS at the Instituto Nacional de Investigaciones Nucleares in Mexico. The objective of the paper is to share the experience gained by the tissue bank personnel [radiosterilised tissue bank (BTR)] at the Instituto Nacional de Investigaciones Nucleares (ININ, National Institute of Nuclear Research), during implementation of the ISO 9001:2000 certification process. At present, the quality management system (QMS) of ININ also complies with the Mexican standard NMX-CC-9001:2000. The scope of this QMS is Research, Development and Processing of Biological Tissues Sterilised by Gamma Radiation, among others.

Processing ultrasound backscatter to monitor high-intensity focused ultrasound (HIFU) therapy

NASA Astrophysics Data System (ADS)

Kaczkowski, Peter J.; Anand, Ajay; Bailey, Michael R.

2005-09-01

The development of new noninvasive surgical methods such as HIFU for the treatment of cancer and internal bleeding requires simultaneous development of new sensing approaches to guide, monitor, and assess the therapy. Ultrasound imaging using echo amplitude has long been used to map tissue morphology for diagnostic interpretation by the clinician. New quantitative ultrasonic methods that rely on amplitude and phase processing for tissue characterization are being developed for monitoring of ablative therapy. We have been developing the use of full wave ultrasound backscattering for real-time temperature estimation, and to image changes in tissue backscatter spectrum as therapy progresses. Both approaches rely on differential processing of the backscatter signal in time, and precise measurement of phase differences. Noise and artifacts from motion and nonstationary speckle statistics are addressed by constraining inversions for tissue parameters with physical models. We present results of HIFU experiments with static point and scanned HIFU exposures in which temperature rise can be accurately mapped using a new heat transfer equation (HTE) model-constrained inverse approach. We also present results of a recently developed spectral imaging method that elucidates microbubble-mediated nonlinearity not visible as a change in backscatter amplitude. [Work supported by Army MRMC.

Vascularization strategies for tissue engineers.

PubMed

Dew, Lindsey; MacNeil, Sheila; Chong, Chuh Khiun

2015-01-01

All tissue-engineered substitutes (with the exception of cornea and cartilage) require a vascular network to provide the nutrient and oxygen supply needed for their survival in vivo. Unfortunately the process of vascular ingrowth into an engineered tissue can take weeks to occur naturally and during this time the tissues become starved of essential nutrients, leading to tissue death. This review initially gives a brief overview of the processes and factors involved in the formation of new vasculature. It then summarizes the different approaches that are being applied or developed to overcome the issue of slow neovascularization in a range of tissue-engineered substitutes. Some potential future strategies are then discussed.

DNA replication machinery is required for development in Drosophila.

PubMed

Kohzaki, Hidetsugu; Asano, Maki; Murakami, Yota

2018-01-01

 In Drosophila , some factors involved in chromosome replication seem to be involved in gene amplification and endoreplication, which are actively utilized in particular tissue development, but direct evidence has not been shown. Therefore, we examined the effect of depletion of replication factors on these processes. First, we confirmed RNAi knockdown can be used for the depletion of replication factors by comparing the phenotypes of RNAi knockdown and deletion or point mutants of the components of DNA licensing factor, MCM2, MCM4 and Cdt1. Next, we found that tissue-specific RNAi knockdown of replication factors caused tissue-specific defects, probably due to defects in DNA replication. In particular, we found that depletion inhibited gene amplification of the chorion gene in follicle cells and endoreplication in salivary glands, showing that chromosomal DNA replication factors are required for these processes. Finally, using RNAi, we screened the genes for chromosomal DNA replication that affected tissue development. Interestingly, wing specific knockdown of Mcm10 induced wing formation defects. These results suggest that some components of chromosomal replication machinery are directly involved in tissue development.

Augmenting endogenous repair of soft tissues with nanofibre scaffolds

PubMed Central

Snelling, Sarah; Dakin, Stephanie; Carr, Andrew

2018-01-01

As our ability to engineer nanoscale materials has developed we can now influence endogenous cellular processes with increasing precision. Consequently, the use of biomaterials to induce and guide the repair and regeneration of tissues is a rapidly developing area. This review focuses on soft tissue engineering, it will discuss the types of biomaterial scaffolds available before exploring physical, chemical and biological modifications to synthetic scaffolds. We will consider how these properties, in combination, can provide a precise design process, with the potential to meet the requirements of the injured and diseased soft tissue niche. Finally, we frame our discussions within clinical trial design and the regulatory framework, the consideration of which is fundamental to the successful translation of new biomaterials. PMID:29695606

Organotypic three-dimensional culture model of mesenchymal and epithelial cells to examine tissue fusion events.

EPA Science Inventory

Tissue fusion during early mammalian development requires coordination of multiple cell types, the extracellular matrix, and complex signaling pathways. Fusion events during processes including heart development, neural tube closure, and palatal fusion are dependent on signaling ...

Development of tissue bank.

PubMed

Narayan, R P

2012-05-01

The history of tissue banking is as old as the use of skin grafting for resurfacing of burn wounds. Beneficial effects of tissue grafts led to wide spread use of auto and allograft for management of varied clinical conditions like skin wounds, bone defects following trauma or tumor ablation. Availability of adequate amount of tissues at the time of requirement was the biggest challenge that forced clinicians to find out techniques to preserve the living tissue for prolonged period of time for later use and thus the foundation of tissue banking was started in early twentieth century. Harvesting, processing, storage and transportation of human tissues for clinical use is the major activity of tissue banks. Low temperature storage of processed tissue is the best preservation technique at present. Tissue banking organization is a very complex system and needs high technical expertise and skilled personnel for proper functioning in a dedicated facility. A small lapse/deviation from the established protocol leads to loss of precious tissues and or harm to recipients as well as the risk of transmission of deadly diseases and tumors. Strict tissue transplant acts and stringent regulations help to streamline the whole process of tissue banking safe for recipients and to community as whole.

The basics of epithelial-mesenchymal transition.

PubMed

Kalluri, Raghu; Weinberg, Robert A

2009-06-01

The origins of the mesenchymal cells participating in tissue repair and pathological processes, notably tissue fibrosis, tumor invasiveness, and metastasis, are poorly understood. However, emerging evidence suggests that epithelial-mesenchymal transitions (EMTs) represent one important source of these cells. As we discuss here, processes similar to the EMTs associated with embryo implantation, embryogenesis, and organ development are appropriated and subverted by chronically inflamed tissues and neoplasias. The identification of the signaling pathways that lead to activation of EMT programs during these disease processes is providing new insights into the plasticity of cellular phenotypes and possible therapeutic interventions.

Emergence of tissue mechanics from cellular processes: shaping a fly wing

NASA Astrophysics Data System (ADS)

Merkel, Matthias; Etournay, Raphael; Popovic, Marko; Nandi, Amitabha; Brandl, Holger; Salbreux, Guillaume; Eaton, Suzanne; Jülicher, Frank

Nowadays, biologistsare able to image biological tissueswith up to 10,000 cells in vivowhere the behavior of each individual cell can be followed in detail.However, how precisely large-scale tissue deformation and stresses emerge from cellular behavior remains elusive. Here, we study this question in the developing wing of the fruit fly. To this end, we first establish a geometrical framework that exactly decomposes tissue deformation into contributions by different kinds of cellular processes. These processes comprise cell shape changes, cell neighbor exchanges, cell divisions, and cell extrusions. As the key idea, we introduce a tiling of the cellular network into triangles. This approach also reveals that tissue deformation can also be created by correlated cellular motion. Based on quantifications using these concepts, we developed a novel continuum mechanical model for the fly wing. In particular, our model includes active anisotropic stresses and a delay in the response of cell rearrangements to material stresses. A different approach to study the emergence of tissue mechanics from cellular behavior are cell-based models. We characterize the properties of a cell-based model for 3D tissues that is a hybrid between single particle models and the so-called vertex models.

The early career researcher's toolkit: translating tissue engineering, regenerative medicine and cell therapy products.

PubMed

Rafiq, Qasim A; Ortega, Ilida; Jenkins, Stuart I; Wilson, Samantha L; Patel, Asha K; Barnes, Amanda L; Adams, Christopher F; Delcassian, Derfogail; Smith, David

2015-11-01

Although the importance of translation for the development of tissue engineering, regenerative medicine and cell-based therapies is widely recognized, the process of translation is less well understood. This is particularly the case among some early career researchers who may not appreciate the intricacies of translational research or make decisions early in development which later hinders effective translation. Based on our own research and experiences as early career researchers involved in tissue engineering and regenerative medicine translation, we discuss common pitfalls associated with translational research, providing practical solutions and important considerations which will aid process and product development. Suggestions range from effective project management, consideration of key manufacturing, clinical and regulatory matters and means of exploiting research for successful commercialization.

Tissue fusion over nonadhering surfaces

PubMed Central

Nier, Vincent; Deforet, Maxime; Duclos, Guillaume; Yevick, Hannah G.; Cochet-Escartin, Olivier; Marcq, Philippe; Silberzan, Pascal

2015-01-01

Tissue fusion eliminates physical voids in a tissue to form a continuous structure and is central to many processes in development and repair. Fusion events in vivo, particularly in embryonic development, often involve the purse-string contraction of a pluricellular actomyosin cable at the free edge. However, in vitro, adhesion of the cells to their substrate favors a closure mechanism mediated by lamellipodial protrusions, which has prevented a systematic study of the purse-string mechanism. Here, we show that monolayers can cover well-controlled mesoscopic nonadherent areas much larger than a cell size by purse-string closure and that active epithelial fluctuations are required for this process. We have formulated a simple stochastic model that includes purse-string contractility, tissue fluctuations, and effective friction to qualitatively and quantitatively account for the dynamics of closure. Our data suggest that, in vivo, tissue fusion adapts to the local environment by coordinating lamellipodial protrusions and purse-string contractions. PMID:26199417

Preanalytics in lung cancer.

PubMed

Warth, Arne; Muley, Thomas; Meister, Michael; Weichert, Wilko

2015-01-01

Preanalytic sampling techniques and preparation of tissue specimens strongly influence analytical results in lung tissue diagnostics both on the morphological but also on the molecular level. However, in contrast to analytics where tremendous achievements in the last decade have led to a whole new portfolio of test methods, developments in preanalytics have been minimal. This is specifically unfortunate in lung cancer, where usually only small amounts of tissue are at hand and optimization in all processing steps is mandatory in order to increase the diagnostic yield. In the following, we provide a comprehensive overview on some aspects of preanalytics in lung cancer from the method of sampling over tissue processing to its impact on analytical test results. We specifically discuss the role of preanalytics in novel technologies like next-generation sequencing and in the state-of the-art cytology preparations. In addition, we point out specific problems in preanalytics which hamper further developments in the field of lung tissue diagnostics.

Three-Dimensional Coculture Of Human Small-Intestine Cells

NASA Technical Reports Server (NTRS)

Wolf, David; Spaulding, Glen; Goodwin, Thomas J.; Prewett, Tracy

1994-01-01

Complex three-dimensional masses of normal human epithelial and mesenchymal small-intestine cells cocultured in process involving specially designed bioreactors. Useful as tissued models for studies of growth, regulatory, and differentiation processes in normal intestinal tissues; diseases of small intestine; and interactions between cells of small intestine and viruses causing disease both in small intestine and elsewhere in body. Process used to produce other tissue models, leading to advances in understanding of growth and differentiation in developing organisms, of renewal of tissue, and of treatment of myriad of clinical conditions. Prior articles describing design and use of rotating-wall culture vessels include "Growing And Assembling Cells Into Tissues" (MSC-21559), "High-Aspect-Ratio Rotating Cell-Culture Vessel" (MSC-21662), and "In Vitro, Matrix-Free Formation Of Solid Tumor Spheroids" (MSC-21843).

Tissue Engineering the Cornea: The Evolution of RAFT

PubMed Central

Levis, Hannah J.; Kureshi, Alvena K.; Massie, Isobel; Morgan, Louise; Vernon, Amanda J.; Daniels, Julie T.

2015-01-01

Corneal blindness affects over 10 million people worldwide and current treatment strategies often involve replacement of the defective layer with healthy tissue. Due to a worldwide donor cornea shortage and the absence of suitable biological scaffolds, recent research has focused on the development of tissue engineering techniques to create alternative therapies. This review will detail how we have refined the simple engineering technique of plastic compression of collagen to a process we now call Real Architecture for 3D Tissues (RAFT). The RAFT production process has been standardised, and steps have been taken to consider Good Manufacturing Practice compliance. The evolution of this process has allowed us to create biomimetic epithelial and endothelial tissue equivalents suitable for transplantation and ideal for studying cell-cell interactions in vitro. PMID:25809689

[Analysis of scatterer microstructure feature based on Chirp-Z transform cepstrum].

PubMed

Guo, Jianzhong; Lin, Shuyu

2007-12-01

The fundamental research field of medical ultrasound has been the characterization of tissue scatterers. The signal processing method is widely used in this research field. A new method of Chirp-Z Transform Cepstrum for mean spacing estimation of tissue scatterers using ultrasonic scattered signals has been developed. By using this method together with conventional AR cepstrum method, we processed the backscattered signals of mimic tissue and pig liver in vitro. The results illustrated that the Chirp-Z Transform Cepstrum method is effective for signal analysis of ultrasonic scattering and characterization of tissue scatterers, and it can improve the resolution for mean spacing estimation of tissue scatterers.

Synthetic Materials for Osteochondral Tissue Engineering.

PubMed

Iulian, Antoniac; Dan, Laptoiu; Camelia, Tecu; Claudia, Milea; Sebastian, Gradinaru

2018-01-01

The objective of an articular cartilage repair treatment is to repair the affected surface of an articular joint's hyaline cartilage. Currently, both biological and tissue engineering research is concerned with discovering the clues needed to stimulate cells to regenerate tissues and organs totally or partially. The latest findings on nanotechnology advances along with the processability of synthetic biomaterials have succeeded in creating a new range of materials to develop into the desired biological responses to the cellular level. 3D printing has a great ability to establish functional tissues or organs to cure or replace abnormal and necrotic tissue, providing a promising solution for serious tissue/organ failure. The 4D print process has the potential to continually revolutionize the current tissue and organ manufacturing platforms. A new active research area is the development of intelligent materials with high biocompatibility to suit 4D printing technology. As various researchers and tissue engineers have demonstrated, the role of growth factors in tissue engineering for repairing osteochondral and cartilage defects is a very important one. Following animal testing, cell-assisted and growth-factor scaffolds produced much better results, while growth-free scaffolds showed a much lower rate of healing.

Rejuvenating Strategies for Stem Cell-based Therapies in Aging

PubMed Central

Neves, Joana; Sousa-Victor, Pedro; Jasper, Heinrich

2017-01-01

SUMMARY Recent advances in our understanding of tissue regeneration and the development of efficient approaches to induce and differentiate pluripotent stem cells for cell replacement therapies promise exciting avenues for treating degenerative age-related diseases. However, clinical studies and insights from model organisms have identified major roadblocks that normal aging processes impose on tissue regeneration. These new insights suggest that specific targeting of environmental niche components, including growth factors, ECM and immune cells, and intrinsic stem cell properties that are affected by aging will be critical for development of new strategies to improve stem cell function and optimize tissue repair processes. PMID:28157498

Virtual Plant Tissue: Building Blocks for Next-Generation Plant Growth Simulation

PubMed Central

De Vos, Dirk; Dzhurakhalov, Abdiravuf; Stijven, Sean; Klosiewicz, Przemyslaw; Beemster, Gerrit T. S.; Broeckhove, Jan

2017-01-01

Motivation: Computational modeling of plant developmental processes is becoming increasingly important. Cellular resolution plant tissue simulators have been developed, yet they are typically describing physiological processes in an isolated way, strongly delimited in space and time. Results: With plant systems biology moving toward an integrative perspective on development we have built the Virtual Plant Tissue (VPTissue) package to couple functional modules or models in the same framework and across different frameworks. Multiple levels of model integration and coordination enable combining existing and new models from different sources, with diverse options in terms of input/output. Besides the core simulator the toolset also comprises a tissue editor for manipulating tissue geometry and cell, wall, and node attributes in an interactive manner. A parameter exploration tool is available to study parameter dependence of simulation results by distributing calculations over multiple systems. Availability: Virtual Plant Tissue is available as open source (EUPL license) on Bitbucket (https://bitbucket.org/vptissue/vptissue). The project has a website https://vptissue.bitbucket.io. PMID:28523006

Regulatory mechanisms for specification and patterning of plant vascular tissues.

PubMed

Caño-Delgado, Ana; Lee, Ji-Young; Demura, Taku

2010-01-01

Plant vascular tissues, the conduits of water, nutrients, and small molecules, play important roles in plant growth and development. Vascular tissues have allowed plants to successfully adapt to various environmental conditions since they evolved 450 Mya. The majority of plant biomass, an important source of renewable energy, comes from the xylem of the vascular tissues. Efforts have been made to identify the underlying mechanisms of cell specification and patterning of plant vascular tissues and their proliferation. The formation of the plant vascular system is a complex process that integrates signaling and gene regulation at transcriptional and posttranscriptional levels. Recently, a wealth of molecular genetic studies and the advent of cell biology and genomic tools have enabled important progress toward understanding its underlying mechanisms. Here, we provide a comprehensive review of the cell and developmental processes of plant vascular tissue and resources recently available for studying them that will enable the discovery of new ways to develop sustainable energy using plant biomass.

Advances in bionanomaterials for bone tissue engineering.

PubMed

Scott, Timothy G; Blackburn, Gary; Ashley, Michael; Bayer, Ilker S; Ghosh, Anindya; Biris, Alexandru S; Biswas, Abhijit

2013-01-01

Bone is a specialized form of connective tissue that forms the skeleton of the body and is built at the nano and microscale levels as a multi-component composite material consisting of a hard inorganic phase (minerals) in an elastic, dense organic network. Mimicking bone structure and its properties present an important frontier in the fields of nanotechnology, materials science and bone tissue engineering, given the complex morphology of this tissue. There has been a growing interest in developing artificial bone-mimetic nanomaterials with controllable mineral content, nanostructure, chemistry for bone, cartilage tissue engineering and substitutes. This review describes recent advances in bionanomaterials for bone tissue engineering including developments in soft tissue engineering. The significance and basic process of bone tissue engineering along with different bionanomaterial bone scaffolds made of nanocomposites and nanostructured biopolymers/bioceramics and the prerequisite biomechanical functions are described. It also covers latest developments in soft-tissue reconstruction and replacement. Finally, perspectives on the future direction in nanotechnology-enabled bone tissue engineering are presented.

Development and validation of a protocol for optimizing the use of paraffin blocks in molecular epidemiological studies: The example from the HPV-AHEAD study.

PubMed

Mena, Marisa; Lloveras, Belen; Tous, Sara; Bogers, Johannes; Maffini, Fausto; Gangane, Nitin; Kumar, Rekha Vijay; Somanathan, Thara; Lucas, Eric; Anantharaman, Devasena; Gheit, Tarik; Castellsagué, Xavier; Pawlita, Michael; de Sanjosé, Silvia; Alemany, Laia; Tommasino, Massimo

2017-01-01

Worldwide use of formalin-fixed paraffin-embedded blocks (FFPE) is extensive in diagnosis and research. Yet, there is a lack of optimized/standardized protocols to process the blocks and verify the quality and presence of the targeted tissue. In the context of an international study on head and neck cancer (HNC)-HPV-AHEAD, a standardized protocol for optimizing the use of FFPEs in molecular epidemiology was developed and validated. First, a protocol for sectioning the FFPE was developed to prevent cross-contamination and distributed between participating centers. Before processing blocks, all sectioning centers underwent a quality control to guarantee a satisfactory training process. The first and last sections of the FFPEs were used for histopathological assessment. A consensus histopathology evaluation form was developed by an international panel of pathologists and evaluated for four indicators in a pilot analysis in order to validate it: 1) presence/type of tumor tissue, 2) identification of other tissue components that could affect the molecular diagnosis and 3) quality of the tissue. No HPV DNA was found in sections from empty FFPE generated in any histology laboratories of HPV-AHEAD consortium and all centers passed quality assurance for processing after quality control. The pilot analysis to validate the histopathology form included 355 HNC cases. The form was filled by six pathologists and each case was randomly assigned to two of them. Most samples (86%) were considered satisfactory. Presence of >50% of invasive carcinoma was observed in all sections of 66% of cases. Substantial necrosis (>50%) was present in <2% of samples. The concordance for the indicators targeted to validate the histopathology form was very high (kappa > 0.85) between first and last sections and fair to high between pathologists (kappa/pabak 0.21-0.72). The protocol allowed to correctly process without signs of contamination all FFPE of the study. The histopathology evaluation of the cases assured the presence of the targeted tissue, identified the presence of other tissues that could disturb the molecular diagnosis and allowed the assessment of tissue quality.

ON THE BIOMECHANICAL FUNCTION OF SCAFFOLDS FOR ENGINEERING LOAD BEARING SOFT TISSUES

PubMed Central

Stella, John A.; D’Amore, Antonio; Wagner, William R.; Sacks, Michael S.

2010-01-01

Replacement or regeneration of load bearing soft tissues has long been the impetus for the development bioactive materials. While maturing, current efforts continue to be confounded by our lack of understanding of the intricate multi-scale hierarchical arrangements and interactions typically found in native tissues. The current state of the art in biomaterial processing enables a degree of controllable microstructure that can be used for the development of model systems to deduce fundamental biological implications of matrix morphologies on cell function. Furthermore, the development of computational frameworks which allow for the simulation of experimentally derived observations represents a positive departure from what has mostly been an empirically driven field, enabling a deeper understanding of the highly complex biological mechanisms we wish to ultimately emulate. Ongoing research is actively pursuing new materials and processing methods to control material structure down to the micro-scale to sustain or improve cell viability, guide tissue growth, and provide mechanical integrity all while exhibiting the capacity to degrade in a controlled manner. The purpose of this review is not to focus solely on material processing but to assess the ability of these techniques to produce mechanically sound tissue surrogates, highlight the unique structural characteristics produced in these materials, and discuss how this translates to distinct macroscopic biomechanical behaviors. PMID:20060509

Skeletogenesis in the swell shark Cephaloscyllium ventriosum.

PubMed

Eames, B Frank; Allen, Nancy; Young, Jonathan; Kaplan, Angelo; Helms, Jill A; Schneider, Richard A

2007-05-01

Extant chondrichthyans possess a predominantly cartilaginous skeleton, even though primitive chondrichthyans produced bone. To gain insights into this peculiar skeletal evolution, and in particular to evaluate the extent to which chondrichthyan skeletogenesis retains features of an osteogenic programme, we performed a histological, histochemical and immunohistochemical analysis of the entire embryonic skeleton during development of the swell shark Cephaloscyllium ventriosum. Specifically, we compared staining properties among various mineralizing tissues, including neural arches of the vertebrae, dermal tissues supporting oral denticles and Meckel's cartilage of the lower jaw. Patterns of mineralization were predicted by spatially restricted alkaline phosphatase activity earlier in development. Regarding evidence for an osteogenic programme in extant sharks, a mineralized tissue in the perichondrium of C. ventriosum neural arches, and to a lesser extent a tissue supporting the oral denticle, displayed numerous properties of bone. Although we uncovered many differences between tissues in Meckel's cartilage and neural arches of C. ventriosum, both elements impart distinct tissue characteristics to the perichondral region. Considering the evolution of osteogenic processes, shark skeletogenesis may illuminate the transition from perichondrium to periosteum, which is a major bone-forming tissue during the process of endochondral ossification.

A Thermo-Poromechanics Finite Element Model for Predicting Arterial Tissue Fusion

NASA Astrophysics Data System (ADS)

Fankell, Douglas P.

This work provides modeling efforts and supplemental experimental work performed towards the ultimate goal of modeling heat transfer, mass transfer, and deformation occurring in biological tissue, in particular during arterial fusion and cutting. Developing accurate models of these processes accomplishes two goals. First, accurate models would enable engineers to design devices to be safer and less expensive. Second, the mechanisms behind tissue fusion and cutting are widely unknown; models with the ability to accurately predict physical phenomena occurring in the tissue will allow for insight into the underlying mechanisms of the processes. This work presents three aims and the efforts in achieving them, leading to an accurate model of tissue fusion and more broadly the thermo-poromechanics (TPM) occurring within biological tissue. Chapters 1 and 2 provide the motivation for developing accurate TPM models of biological tissue and an overview of previous modeling efforts. In Chapter 3, a coupled thermo-structural finite element (FE) model with the ability to predict arterial cutting is offered. From the work presented in Chapter 3, it became obvious a more detailed model was needed. Chapter 4 meets this need by presenting small strain TPM theory and its implementation in an FE code. The model is then used to simulate thermal tissue fusion. These simulations show the model's promise in predicting the water content and temperature of arterial wall tissue during the fusion process, but it is limited by its small deformation assumptions. Chapters 5-7 attempt to address this limitation by developing and implementing a large deformation TPM FE model. Chapters 5, 6, and 7 present a thermodynamically consistent, large deformation TPM FE model and its ability to simulate tissue fusion. Ultimately, this work provides several methods of simulating arterial tissue fusion and the thermo-poromechanics of biological tissue. It is the first work, to the author's knowledge, to simulate the fully coupled TPM of biological tissue and the first to present a fully coupled large deformation TPM FE model. In doing so, a stepping stone for more advanced modeling of biological tissue has been laid.

Calcium as a signal integrator in developing epithelial tissues.

PubMed

Brodskiy, Pavel A; Zartman, Jeremiah J

2018-05-16

Decoding how tissue properties emerge across multiple spatial and temporal scales from the integration of local signals is a grand challenge in quantitative biology. For example, the collective behavior of epithelial cells is critical for shaping developing embryos. Understanding how epithelial cells interpret a diverse range of local signals to coordinate tissue-level processes requires a systems-level understanding of development. Integration of multiple signaling pathways that specify cell signaling information requires second messengers such as calcium ions. Increasingly, specific roles have been uncovered for calcium signaling throughout development. Calcium signaling regulates many processes including division, migration, death, and differentiation. However, the pleiotropic and ubiquitous nature of calcium signaling implies that many additional functions remain to be discovered. Here we review a selection of recent studies to highlight important insights into how multiple signals are transduced by calcium transients in developing epithelial tissues. Quantitative imaging and computational modeling have provided important insights into how calcium signaling integration occurs. Reverse-engineering the conserved features of signal integration mediated by calcium signaling will enable novel approaches in regenerative medicine and synthetic control of morphogenesis.

Tissue mechanics regulate brain development, homeostasis and disease

PubMed Central

Barnes, J. Matthew

2017-01-01

ABSTRACT All cells sense and integrate mechanical and biochemical cues from their environment to orchestrate organismal development and maintain tissue homeostasis. Mechanotransduction is the evolutionarily conserved process whereby mechanical force is translated into biochemical signals that can influence cell differentiation, survival, proliferation and migration to change tissue behavior. Not surprisingly, disease develops if these mechanical cues are abnormal or are misinterpreted by the cells – for example, when interstitial pressure or compression force aberrantly increases, or the extracellular matrix (ECM) abnormally stiffens. Disease might also develop if the ability of cells to regulate their contractility becomes corrupted. Consistently, disease states, such as cardiovascular disease, fibrosis and cancer, are characterized by dramatic changes in cell and tissue mechanics, and dysregulation of forces at the cell and tissue level can activate mechanosignaling to compromise tissue integrity and function, and promote disease progression. In this Commentary, we discuss the impact of cell and tissue mechanics on tissue homeostasis and disease, focusing on their role in brain development, homeostasis and neural degeneration, as well as in brain cancer. PMID:28043968

Additive Manufacturing of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/poly(ε-caprolactone) Blend Scaffolds for Tissue Engineering.

PubMed

Puppi, Dario; Morelli, Andrea; Chiellini, Federica

2017-05-24

Additive manufacturing of scaffolds made of a polyhydroxyalkanoate blended with another biocompatible polymer represents a cost-effective strategy for combining the advantages of the two blend components in order to develop tailored tissue engineering approaches. The aim of this study was the development of novel poly(3-hydroxybutyrate- co -3-hydroxyhexanoate)/ poly(ε-caprolactone) (PHBHHx/PCL) blend scaffolds for tissue engineering by means of computer-aided wet-spinning, a hybrid additive manufacturing technique suitable for processing polyhydroxyalkanoates dissolved in organic solvents. The experimental conditions for processing tetrahydrofuran solutions containing the two polymers at different concentrations (PHBHHx/PCL weight ratio of 3:1, 2:1 or 1:1) were optimized in order to manufacture scaffolds with predefined geometry and internal porous architecture. PHBHHx/PCL scaffolds with a 3D interconnected network of macropores and a local microporosity of the polymeric matrix, as a consequence of the phase inversion process governing material solidification, were successfully fabricated. As shown by scanning electron microscopy, thermogravimetric, differential scanning calorimetric and uniaxial compressive analyses, blend composition significantly influenced the scaffold morphological, thermal and mechanical properties. In vitro biological characterization showed that the developed scaffolds were able to sustain the adhesion and proliferation of MC3T3-E1 murine preosteoblast cells. The additive manufacturing approach developed in this study, based on a polymeric solution processing method avoiding possible material degradation related to thermal treatments, could represent a powerful tool for the development of customized PHBHHx-based blend scaffolds for tissue engineering.

Development of rheological characterization and twin-screw extrusion/spiral winding processing methods for functionally-graded tissue engineering scaffolds and characterization of cell/biomaterial interactions

NASA Astrophysics Data System (ADS)

Ozkan, Seher

Tissue engineering involves the fabrication of biodegradable scaffolds, on which various types of cells are grown, to provide tissue constructs for tissue repair/regeneration. Native tissues have complex structures, with functions and properties changing spatially and temporally, and require special tailoring of tissue engineering scaffolds to allow mimicking of their complex elegance. The understanding of the rheological behavior of the biodegradable polymer and the thermo-mechanical history that the polymer experiences during processing is critical in fabricating scaffolds with appropriate microstructural distributions. This study has first focused on the rheological material functions of various gel-like fluids including biofluids and hydrogels, which can emulate the viscoelastic behavior of biofluids. Viscoplasticity and wall slip were recognized as key attributes of such systems. Furthermore, a new technology base involving twin-screw extrusion/spiral winding (TSESW) process was developed for the shaping of functionally-graded scaffolds. This novel scaffold fabrication technology was applied to the development of polycaprolactone (PCL) scaffolds, incorporated with tricalcium phosphate nanoparticles and various porogens in graded fashion. The protein encapsulation and controlled release capabilities of the TSESW process was also demonstrated by dispersing bovine serum albumin (BSA) protein into the PCL matrix. Effects of processing conditions and porosity distributions on compressive properties, surface topography, encapsulation efficiency, release profiles and the secondary structure of BSA were investigated. The PCL scaffolds were determined to be biocompatible, with the proliferation rates of human fetal osteoblast cells (hFOB) increasing with increasing porosity and decreasing concentration of TCP. BSA proteins were determined to be denatured to a greater extent with melt extrusion in the 80-100°C range (in comparison to wet extrusion using organic solvents). Finally, the surface topographies of melt processed poly(L-lactic acid) (ranging from nanoindentations to spherulitic protrusions) were determined to affect the orientation directions of fibroblast and osteoblast-like cells and the spherulitic surfaces giving rise to reduced proliferation rates of fibroblasts.

Status quo of management of the human tissue banks in Taiwan.

PubMed

Chou, Ching-Pang; Chou, Szu-Cheng; Chen, Ying-Hua; Chen, Yu-Hsuan; Lee, Ming-Shin

2017-03-01

As the technologies associated with transplantation and biological tissue engineering continue to advance, human cells and tissues form an integral part to the practice of regenerative medicine. The patient's use of tissues entails the risk of introducing, transmitting and spreading communicable diseases. To prevent such risk and to ensure that the human organs, tissues and cells remain intact and functional after being handled and processed, the transplanted tissues must be subject to good management standards through all stages of collection, screening, processing, storage and distribution as the safety of the users is of the utmost importance. On February 2009, the government of Taiwan promulgated the Regulations for Administration on Human Organ Bank that requires all human tissues banks to adhere to the Good Tissue Practice for Human Organ, Tissue and Cell in terms of establishment and operation in order to cope with the international management trend and the development and management need of the domestic industry. Six years have passed since the law became effective. This article seeks to introduce the current management mechanism and status quo of management of human tissue banks in Taiwan. We also conducted statistical analysis of the data relating to the tissue banks to identify potential risks and the room for improvement. The study concludes that human tissue banks in Taiwan are on the right track with their management practice, leading to a state of steady development and progress.

A practical model for economic evaluation of tissue-engineered therapies.

PubMed

Tan, Tien-En; Peh, Gary S L; Finkelstein, Eric A; Mehta, Jodhbir S

2015-01-01

Tissue-engineered therapies are being developed across virtually all fields of medicine. Some of these therapies are already in clinical use, while others are still in clinical trials or the experimental phase. Most initial studies in the evaluation of new therapies focus on demonstration of clinical efficacy. However, cost considerations or economic viability are just as important. Many tissue-engineered therapies have failed to be impactful because of shortcomings in economic competitiveness, rather than clinical efficacy. Furthermore, such economic viability studies should be performed early in the process of development, before significant investment has been made. Cost-minimization analysis combined with sensitivity analysis is a useful model for the economic evaluation of new tissue-engineered therapies. The analysis can be performed early in the development process, and can provide valuable information to guide further investment and research. The utility of the model is illustrated with the practical real-world example of tissue-engineered constructs for corneal endothelial transplantation. The authors have declared no conflicts of interest for this article. © 2015 Wiley Periodicals, Inc.

Business Process Flow Diagrams in Tissue Bank Informatics System Design, and Identification and Communication of Best Practices: The Pharmaceutical Industry Experience.

PubMed

McDonald, Sandra A; Velasco, Elizabeth; Ilasi, Nicholas T

2010-12-01

Pfizer, Inc.'s Tissue Bank, in conjunction with Pfizer's BioBank (biofluid repository), endeavored to create an overarching internal software package to cover all general functions of both research facilities, including sample receipt, reconciliation, processing, storage, and ordering. Business process flow diagrams were developed by the Tissue Bank and Informatics teams as a way of characterizing best practices both within the Bank and in its interactions with key internal and external stakeholders. Besides serving as a first step for the software development, such formalized process maps greatly assisted the identification and communication of best practices and the optimization of current procedures. The diagrams shared here could assist other biospecimen research repositories (both pharmaceutical and other settings) for comparative purposes or as a guide to successful informatics design. Therefore, it is recommended that biorepositories consider establishing formalized business process flow diagrams for their laboratories, to address these objectives of communication and strategy.

Engineering epithelial-stromal interactions in vitro for toxicology assessment.

PubMed

Belair, David G; Abbott, Barbara D

2017-05-01

Crosstalk between epithelial and stromal cells drives the morphogenesis of ectodermal organs during development and promotes normal mature adult epithelial tissue homeostasis. Epithelial-stromal interactions (ESIs) have historically been examined using mammalian models and ex vivo tissue recombination. Although these approaches have elucidated signaling mechanisms underlying embryonic morphogenesis processes and adult mammalian epithelial tissue function, they are limited by the availability of tissue, low throughput, and human developmental or physiological relevance. In this review, we describe how bioengineered ESIs, using either human stem cells or co-cultures of human primary epithelial and stromal cells, have enabled the development of human in vitro epithelial tissue models that recapitulate the architecture, phenotype, and function of adult human epithelial tissues. We discuss how the strategies used to engineer mature epithelial tissue models in vitro could be extrapolated to instruct the design of organotypic culture models that can recapitulate the structure of embryonic ectodermal tissues and enable the in vitro assessment of events critical to organ/tissue morphogenesis. Given the importance of ESIs towards normal epithelial tissue development and function, such models present a unique opportunity for toxicological screening assays to incorporate ESIs to assess the impact of chemicals on mature and developing epidermal tissues. Published by Elsevier B.V.

Engineering epithelial-stromal interactions in vitro for toxicology assessment

PubMed Central

Belair, David G.; Abbott, Barbara D.

2018-01-01

Crosstalk between epithelial and stromal cells drives the morphogenesis of ectodermal organs during development and promotes normal mature adult epithelial tissue homeostasis. Epithelial-stromal interactions (ESIs) have historically been examined using mammalian models and ex vivo tissue recombination. Although these approaches have elucidated signaling mechanisms underlying embryonic morphogenesis processes and adult mammalian epithelial tissue function, they are limited by the availability of tissue, low throughput, and human developmental or physiological relevance. In this review, we describe how bioengineered ESIs, using either human stem cells or co-cultures of human primary epithelial and stromal cells, have enabled the development of human in vitro epithelial tissue models that recapitulate the architecture, phenotype, and function of adult human epithelial tissues. We discuss how the strategies used to engineer mature epithelial tissue models in vitro could be extrapolated to instruct the design of organotypic culture models that can recapitulate the structure of embryonic ectodermal tissues and enable the in vitro assessment of events critical to organ/tissue morphogenesis. Given the importance of ESIs towards normal epithelial tissue development and function, such models present a unique opportunity for toxicological screening assays to incorporate ESIs to assess the impact of chemicals on mature and developing epidermal tissues. PMID:28285100

Blue fingerprint in spectrum of cancer change of biotissues

NASA Astrophysics Data System (ADS)

Yermolenko, Sergey B.

2010-11-01

This paper follows to combine optical and biochemical techniques for identification the cell membrane transformation in the dynamic of growth and development of experimental solid tumour. It is researched that in all the cases the linear dichroism appears in biotissues (the human esophagus, the muscle tissue of rats, prostate tissue) with the cancer disease the magnitude of which depends on the type of the tissue and on the time of the cancer process development. As the linear dichroism is lacking for healthy tissues, then the obtained results can have diagnostic values with the purpose of detection and estimation of the stage of the cancer disease development.

Spectropolarimetry features of biotissue's malignant changes

NASA Astrophysics Data System (ADS)

Gruia, I.; Yermolenko, S. B.; Gavrila, C.; Ivashko, P. V.; Gruia, M. I.

2010-11-01

This paper follows to combine optical and biochemical techniques for identification the cell membrane transformation in the dynamic of growth and development of experimental solid tumour. It is researched that in all the cases the linear dichroism appears in biotissues (the human esophagus, the muscle tissue of rats, prostate tissue) with the cancer disease the magnitude of which depends on the type of the tissue and on the time of the cancer process development. As the linear dichroism is lacking for healthy tissues, then the obtained results can have diagnostic values with the purpose of detection and estimation of the stage of the cancer disease development.

Unified quantitative characterization of epithelial tissue development

PubMed Central

Guirao, Boris; Rigaud, Stéphane U; Bosveld, Floris; Bailles, Anaïs; López-Gay, Jesús; Ishihara, Shuji; Sugimura, Kaoru

2015-01-01

Understanding the mechanisms regulating development requires a quantitative characterization of cell divisions, rearrangements, cell size and shape changes, and apoptoses. We developed a multiscale formalism that relates the characterizations of each cell process to tissue growth and morphogenesis. Having validated the formalism on computer simulations, we quantified separately all morphogenetic events in the Drosophila dorsal thorax and wing pupal epithelia to obtain comprehensive statistical maps linking cell and tissue scale dynamics. While globally cell shape changes, rearrangements and divisions all significantly participate in tissue morphogenesis, locally, their relative participations display major variations in space and time. By blocking division we analyzed the impact of division on rearrangements, cell shape changes and tissue morphogenesis. Finally, by combining the formalism with mechanical stress measurement, we evidenced unexpected interplays between patterns of tissue elongation, cell division and stress. Our formalism provides a novel and rigorous approach to uncover mechanisms governing tissue development. DOI: http://dx.doi.org/10.7554/eLife.08519.001 PMID:26653285

A tissue retrieval and postharvest processing regimen for rodent reproductive tissues compatible with long-term storage on the international space station and postflight biospecimen sharing program.

PubMed

Gupta, Vijayalaxmi; Holets-Bondar, Lesya; Roby, Katherine F; Enders, George; Tash, Joseph S

2015-01-01

Collection and processing of tissues to preserve space flight effects from animals after return to Earth is challenging. Specimens must be harvested with minimal time after landing to minimize postflight readaptation alterations in protein expression/translation, posttranslational modifications, and expression, as well as changes in gene expression and tissue histological degradation after euthanasia. We report the development of a widely applicable strategy for determining the window of optimal species-specific and tissue-specific posteuthanasia harvest that can be utilized to integrate into multi-investigator Biospecimen Sharing Programs. We also determined methods for ISS-compatible long-term tissue storage (10 months at -80°C) that yield recovery of high quality mRNA and protein for western analysis after sample return. Our focus was reproductive tissues. The time following euthanasia where tissues could be collected and histological integrity was maintained varied with tissue and species ranging between 1 and 3 hours. RNA quality was preserved in key reproductive tissues fixed in RNAlater up to 40 min after euthanasia. Postfixation processing was also standardized for safe shipment back to our laboratory. Our strategy can be adapted for other tissues under NASA's Biospecimen Sharing Program or similar multi-investigator tissue sharing opportunities.

The Prostate, Lung, Colorectal and Ovarian Cancer (PLCO) Screening Trial Pathology Tissue Resource.

PubMed

Zhu, Claire S; Huang, Wen-Yi; Pinsky, Paul F; Berg, Christine D; Sherman, Mark; Yu, Kelly J; Carrick, Danielle M; Black, Amanda; Hoover, Robert; Lenz, Petra; Williams, Craig; Hawkins, Laura; Chaloux, Matthew; Yurgalevitch, Susan; Mathew, Sunitha; Miller, Amy; Olivo, Vanessa; Khan, Asia; Pretzel, Shannon M; Multerer, Deborah; Beckmann, Patricia; Broski, Karen G; Freedman, Neal D

2016-12-01

Pathology tissue specimens with associated epidemiologic and clinical data are valuable for cancer research. The Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Trial undertook a large-scale effort to create a public resource of pathology tissues from PLCO participants who developed a cancer during the trial. Formalin-fixed paraffin-embedded tissue blocks were obtained from pathology laboratories on a loan basis for central processing of tissue microarrays, with additional free-standing tissue cores collected for nucleic acid extraction. Pathology tissue specimens were obtained for prostate cancer (n = 1,052), lung cancer (n = 434), colorectal cancer (n = 675) and adenoma (n = 658), ovarian cancer and borderline tumors (n = 212), breast cancer (n = 870), and bladder cancer (n = 204). The process of creating this resource was complex, involving multidisciplinary teams with expertise in pathology, epidemiology, information technology, project management, and specialized laboratories. Creating the PLCO tissue resource required a multistep process, including obtaining medical records and contacting pathology departments where pathology materials were stored after obtaining necessary patient consent and authorization. The potential to link tissue biomarkers to prospectively collected epidemiologic information, screening and clinical data, and matched blood or buccal samples offers valuable opportunities to study etiologic heterogeneity, mechanisms of carcinogenesis, and biomarkers for early detection and prognosis. The methods and protocols developed for this effort, and the detailed description of this resource provided here, will be useful for those seeking to use PLCO pathology tissue specimens for their research and may also inform future tissue collection efforts in other settings. Cancer Epidemiol Biomarkers Prev; 25(12); 1635-42. ©2016 AACR. ©2016 American Association for Cancer Research.

Autologous osteoblast transplantation, an innovative method of bone defect treatment: role of a tissue and cell bank in the process.

PubMed

Olender, E; Brubaker, S; Uhrynowska-Tyszkiewicz, I; Wojtowicz, A; Kaminski, A

2014-10-01

The idea of cell treatment of various diseases and medical conditions has become very popular. Some procedures are well established, as is autologous chondrocyte implantation, whereas others are still in the process of early development, laboratory experiments, and some clinical trials. This report is devoted to an example of an emerging cell treatment: bone augmentation with the use of autologous cells and its legal and technical background. Various requirements set by law must be met by tissue banks performing cell seeding of grafts. In Europe, the requirements are described in directives 2004/23/EC, 2006/17/EC, 2006/86/EC, and in the regulation 2007/1394/EC. Revitalization of biostatic allografts gives new, promising tools for creation of functional parts of organs; brings the methodology used in tissue banks closer to tissue engineering; places the enterprise in the mainstream of advanced biotechnology; allows the full potential of tissue allografts; and opens a new, large area for clinical and laboratory research. Cell and tissue processing also have a financial impact on the treatment: it produces additional expenditures. Clinical effectiveness will be the most decisive factor of whether this innovative treatment will be applied in a particular type of medical condition. From a tissue establishment perspective, the most important issue is to develop a procedure that ensures safety for the patient in graft quality terms.

Extracellular Matrix Degradation and Remodeling in Development and Disease

PubMed Central

Lu, Pengfei; Takai, Ken; Weaver, Valerie M.; Werb, Zena

2011-01-01

The extracellular matrix (ECM) serves diverse functions and is a major component of the cellular microenvironment. The ECM is a highly dynamic structure, constantly undergoing a remodeling process where ECM components are deposited, degraded, or otherwise modified. ECM dynamics are indispensible during restructuring of tissue architecture. ECM remodeling is an important mechanism whereby cell differentiation can be regulated, including processes such as the establishment and maintenance of stem cell niches, branching morphogenesis, angiogenesis, bone remodeling, and wound repair. In contrast, abnormal ECM dynamics lead to deregulated cell proliferation and invasion, failure of cell death, and loss of cell differentiation, resulting in congenital defects and pathological processes including tissue fibrosis and cancer. Understanding the mechanisms of ECM remodeling and its regulation, therefore, is essential for developing new therapeutic interventions for diseases and novel strategies for tissue engineering and regenerative medicine. PMID:21917992

Polyamine interactions with plant hormones: crosstalk at several levels

USDA-ARS?s Scientific Manuscript database

Polyamines play important roles in diverse plant growth and development processes including seed germination, tissue lignification, organogenesis, flowering, pollination, embryogenesis, fruit development, ripening, abscission, senescence and stress responses. In all these processes, synergistic and ...

Curriculum in biomedical optics and laser-tissue interactions

NASA Astrophysics Data System (ADS)

Jacques, Steven L.

2003-10-01

A graduate student level curriculum has been developed for teaching the basic principles of how lasers and light interact with biological tissues and materials. The field of Photomedicine can be divided into two topic areas: (1) where tissue affects photons, used for diagnostic sensing, imaging, and spectroscopy of tissues and biomaterials, and (2) where photons affect tissue, used for surgical and therapeutic cutting, dissecting, machining, processing, coagulating, welding, and oxidizing tissues and biomaterials. The courses teach basic principles of tissue optical properties and light transport in tissues, and interaction of lasers and conventional light sources with tissues via photochemical, photothermal and photomechanical mechanisms.

The Impact of Biomechanics in Tissue Engineering and Regenerative Medicine

PubMed Central

Butler, David L.; Goldstein, Steven A.; Guo, X. Edward; Kamm, Roger; Laurencin, Cato T.; McIntire, Larry V.; Mow, Van C.; Nerem, Robert M.; Sah, Robert L.; Soslowsky, Louis J.; Spilker, Robert L.; Tranquillo, Robert T.

2009-01-01

Biomechanical factors profoundly influence the processes of tissue growth, development, maintenance, degeneration, and repair. Regenerative strategies to restore damaged or diseased tissues in vivo and create living tissue replacements in vitro have recently begun to harness advances in understanding of how cells and tissues sense and adapt to their mechanical environment. It is clear that biomechanical considerations will be fundamental to the successful development of clinical therapies based on principles of tissue engineering and regenerative medicine for a broad range of musculoskeletal, cardiovascular, craniofacial, skin, urinary, and neural tissues. Biomechanical stimuli may in fact hold the key to producing regenerated tissues with high strength and endurance. However, many challenges remain, particularly for tissues that function within complex and demanding mechanical environments in vivo. This paper reviews the present role and potential impact of experimental and computational biomechanics in engineering functional tissues using several illustrative examples of past successes and future grand challenges. PMID:19583462

Role of mineralization inhibitors in the regulation of hard tissue biomineralization: relevance to initial enamel formation and maturation

PubMed Central

Margolis, Henry C.; Kwak, Seo-Young; Yamazaki, Hajime

2014-01-01

Vertebrate mineralized tissues, i.e., enamel, dentin, cementum, and bone, have unique hierarchical structures and chemical compositions. Although these tissues are similarly comprised of a crystalline calcium apatite mineral phase and a protein component, they differ with respect to crystal size and shape, level and distribution of trace mineral ions, the nature of the proteins present, and their relative proportions of mineral and protein components. Despite apparent differences, mineralized tissues are similarly derived by highly concerted extracellular processes involving matrix proteins, proteases, and mineral ion fluxes that collectively regulate the nucleation, growth and organization of forming mineral crystals. Nature, however, provides multiple ways to control the onset, rate, location, and organization of mineral deposits in developing mineralized tissues. Although our knowledge is quite limited in some of these areas, recent evidence suggests that hard tissue formation is, in part, controlled through the regulation of specific molecules that inhibit the mineralization process. This paper addresses the role of mineralization inhibitors in the regulation of biological mineralization with emphasis on the relevance of current findings to the process of amelogenesis. Mineralization inhibitors can also serve to maintain driving forces for calcium phosphate precipitation and prevent unwanted mineralization. Recent evidence shows that native phosphorylated amelogenins have the capacity to prevent mineralization through the stabilization of an amorphous calcium phosphate precursor phase, as observed in vitro and in developing teeth. Based on present findings, the authors propose that the transformation of initially formed amorphous mineral deposits to enamel crystals is an active process associated with the enzymatic processing of amelogenins. Such processing may serve to control both initial enamel crystal formation and subsequent maturation. PMID:25309443

Heterochronic parabiosis for the study of the effects of aging on stem cells and their niches

PubMed Central

Conboy, Irina M.; Rando, Thomas A.

2012-01-01

Aging is unmistakable and undeniable in mammals. Interestingly, mice develop cataracts, muscle atrophy, osteoporosis, obesity, diabetes and cognitive deficits after just 2–3 postnatal years, while it takes seven or more decades for the same age-specific phenotypes to develop in humans. Thus, chronological age corresponds differently with biological age in metazoan species and although many theories exist, we do not understand what controls the rate of mammalian aging. One interesting idea is that species-specific rate of aging represents a ratio of tissue attrition to tissue regeneration. Furthermore, current findings suggest that the age-imposed biochemical changes in the niches of tissue stem cells inhibit performance of this regenerative pool, which leads to the decline of tissue maintenance and repair. If true, slowing down stem cell and niche aging, thereby promoting tissue regeneration, could slow down the process of tissue and organismal aging. In this regard, recent studies of heterochronic parabiosis provide important clues as to the mechanisms of stem cell aging and suggest novel strategies for enhancing tissue repair in the old. Here we review current literature on the relationship between the vigor of tissue stem cells and the process of aging, with an emphasis on the rejuvenation of old tissues by the extrinsic modifications of stem cell niches. PMID:22617385

Effect of wine and vinegar processing of Rhizoma Corydalis on the tissue distribution of tetrahydropalmatine, protopine and dehydrocorydaline in rats.

PubMed

Dou, Zhiying; Li, Kefeng; Wang, Ping; Cao, Liu

2012-01-18

Vinegar and wine processing of medicinal plants are two traditional pharmaceutical techniques which have been used for thousands of years in China. Tetrahydropalmatine (THP), dehydrocorydaline (DHC) and protopine are three major bioactive molecules in Rhizoma Corydalis. In this study, a simple and reliable HPLC method was developed for simultaneous analysis of THP, DHC and protopine in rat tissues after gastric gavage administration of Rhizoma Corydalis. The validated HPLC method was successfully applied to investigate the effect of wine and vinegar processing on the compounds' distribution in rat tissues. Our results showed that processing mainly affect the T(max) and mean residence time (MRT) of the molecules without changing their C(max) and AUC(0-24)( )(h) Vinegar processing significantly increased the T(max) of DHC in heart, kidney, cerebrum, cerebrellum, brain stem and striatum and prolonged the T(max) of protopine in brain. No significant changes were observed on the T(max) of THP in rat tissues after vinegar processing. Wine processing reduced the T(max) of protopine and DHC in liver and spleen and T(max) of protopine in lung, but increased the T(max) of THP in all the rat tissues examined. To our knowledge, this is the first report on the effects of processing on the tissue distribution of the bioactive molecules from Rhizoma Corydalis.

Biodynamic Doppler imaging of subcellular motion inside 3D living tissue culture and biopsies (Conference Presentation)

NASA Astrophysics Data System (ADS)

Nolte, David D.

2016-03-01

Biodynamic imaging is an emerging 3D optical imaging technology that probes up to 1 mm deep inside three-dimensional living tissue using short-coherence dynamic light scattering to measure the intracellular motions of cells inside their natural microenvironments. Biodynamic imaging is label-free and non-invasive. The information content of biodynamic imaging is captured through tissue dynamics spectroscopy that displays the changes in the Doppler signatures from intracellular constituents in response to applied compounds. The affected dynamic intracellular mechanisms include organelle transport, membrane undulations, cytoskeletal restructuring, strain at cellular adhesions, cytokinesis, mitosis, exo- and endo-cytosis among others. The development of 3D high-content assays such as biodynamic profiling can become a critical new tool for assessing efficacy of drugs and the suitability of specific types of tissue growth for drug discovery and development. The use of biodynamic profiling to predict clinical outcome of living biopsies to cancer therapeutics can be developed into a phenotypic companion diagnostic, as well as a new tool for therapy selection in personalized medicine. This invited talk will present an overview of the optical, physical and physiological processes involved in biodynamic imaging. Several different biodynamic imaging modalities include motility contrast imaging (MCI), tissue-dynamics spectroscopy (TDS) and tissue-dynamics imaging (TDI). A wide range of potential applications will be described that include process monitoring for 3D tissue culture, drug discovery and development, cancer therapy selection, embryo assessment for in-vitro fertilization and artificial reproductive technologies, among others.

Development of 3D in Vitro Technology for Medical Applications

PubMed Central

Ou, Keng-Liang; Hosseinkhani, Hossein

2014-01-01

In the past few years, biomaterials technologies together with significant efforts on developing biology have revolutionized the process of engineered materials. Three dimensional (3D) in vitro technology aims to develop set of tools that are simple, inexpensive, portable and robust that could be commercialized and used in various fields of biomedical sciences such as drug discovery, diagnostic tools, and therapeutic approaches in regenerative medicine. The proliferation of cells in the 3D scaffold needs an oxygen and nutrition supply. 3D scaffold materials should provide such an environment for cells living in close proximity. 3D scaffolds that are able to regenerate or restore tissue and/or organs have begun to revolutionize medicine and biomedical science. Scaffolds have been used to support and promote the regeneration of tissues. Different processing techniques have been developed to design and fabricate three dimensional scaffolds for tissue engineering implants. Throughout the chapters we discuss in this review, we inform the reader about the potential applications of different 3D in vitro systems that can be applied for fabricating a wider range of novel biomaterials for use in tissue engineering. PMID:25299693

Design, Materials, and Mechanobiology of Biodegradable Scaffolds for Bone Tissue Engineering

PubMed Central

Velasco, Marco A.; Narváez-Tovar, Carlos A.; Garzón-Alvarado, Diego A.

2015-01-01

A review about design, manufacture, and mechanobiology of biodegradable scaffolds for bone tissue engineering is given. First, fundamental aspects about bone tissue engineering and considerations related to scaffold design are established. Second, issues related to scaffold biomaterials and manufacturing processes are discussed. Finally, mechanobiology of bone tissue and computational models developed for simulating how bone healing occurs inside a scaffold are described. PMID:25883972

Differential tissue growth and cell adhesion alone drive early tooth morphogenesis: An ex vivo and in silico study

PubMed Central

Savriama, Yoland; Jernvall, Jukka

2018-01-01

From gastrulation to late organogenesis animal development involves many genetic and bio-mechanical interactions between epithelial and mesenchymal tissues. Ectodermal organs, such as hairs, feathers and teeth are well studied examples of organs whose development is based on epithelial-mesenchymal interactions. These develop from a similar primordium through an epithelial folding and its interaction with the mesenchyme. Despite extensive knowledge on the molecular pathways involved, little is known about the role of bio-mechanical processes in the morphogenesis of these organs. We propose a simple computational model for the biomechanics of one such organ, the tooth, and contrast its predictions against cell-tracking experiments, mechanical relaxation experiments and the observed tooth shape changes over developmental time. We found that two biomechanical processes, differential tissue growth and differential cell adhesion, were enough, in the model, for the development of the 3D morphology of the early tooth germ. This was largely determined by the length and direction of growth of the cervical loops, lateral folds of the enamel epithelium. The formation of these cervical loops was found to require accelerated epithelial growth relative to other tissues and their direction of growth depended on specific differential adhesion between the three tooth tissues. These two processes and geometrical constraints in early tooth bud also explained the shape asymmetry between the lateral cervical loops and those forming in the anterior and posterior of the tooth. By performing mechanical perturbations ex vivo and in silico we inferred the distribution and direction of tensile stresses in the mesenchyme that restricted cervical loop lateral growth and forced them to grow downwards. Overall our study suggests detailed quantitative explanations for how bio-mechanical processes lead to specific morphological 3D changes over developmental time. PMID:29481561

Tissue Physiology and Pathology of Aromatase

PubMed Central

Stocco, Carlos

2011-01-01

Summary Aromatase is expressed in multiple tissues, indicating a crucial role for locally produced oestrogens in the differentiation, regulation and normal function of several organs and processes. This review is an overview of the role of aromatase in different tissues under normal physiological conditions and its contribution to the development of some oestrogen-related pathologies. PMID:22108547

microRNA expression profiling in fetal single ventricle malformation identified by deep sequencing.

PubMed

Yu, Zhang-Bin; Han, Shu-Ping; Bai, Yun-Fei; Zhu, Chun; Pan, Ya; Guo, Xi-Rong

2012-01-01

microRNAs (miRNAs) have emerged as key regulators in many biological processes, particularly cardiac growth and development, although the specific miRNA expression profile associated with this process remains to be elucidated. This study aimed to characterize the cellular microRNA profile involved in the development of congenital heart malformation, through the investigation of single ventricle (SV) defects. Comprehensive miRNA profiling in human fetal SV cardiac tissue was performed by deep sequencing. Differential expression of 48 miRNAs was revealed by sequencing by oligonucleotide ligation and detection (SOLiD) analysis. Of these, 38 were down-regulated and 10 were up-regulated in differentiated SV cardiac tissue, compared to control cardiac tissue. This was confirmed by real-time quantitative reverse transcription-polymerase chain reaction (qRT-PCR) analysis. Predicted target genes of the 48 differentially expressed miRNAs were analyzed by gene ontology and categorized according to cellular process, regulation of biological process and metabolic process. Pathway-Express analysis identified the WNT and mTOR signaling pathways as the most significant processes putatively affected by the differential expression of these miRNAs. The candidate genes involved in cardiac development were identified as potential targets for these differentially expressed microRNAs and the collaborative network of microRNAs and cardiac development related-mRNAs was constructed. These data provide the basis for future investigation of the mechanism of the occurrence and development of fetal SV malformations.

The effects of different preservation processes on the total protein and growth factor content in a new biological product developed from human amniotic membrane.

PubMed

Russo, Alessandra; Bonci, Paola; Bonci, Paolo

2012-06-01

The aim of this work is to quantify the total protein and growth factors content in a tissue-suspension obtained from processed human amniotic membrane (hAM). hAM was collected, frozen, freeze dried, powdered and sterilized by γ-irradiation. At each step of the process, samples were characterized for the total protein amounts by a Bradford protein assay and for the growth factor concentrations by ELISA test of the tissue suspensions. Frozen-hAM samples show higher release of total proteins and specific growth factors in the tissue suspension in comparison with freeze-dried hAM. We observed that even if the protein extraction is hindered once the tissue is dried, the powdering process allows a greater release in the tissue suspension of total proteins and growth factors after tissue re-solubilization in comparison with only the freeze-drying process (+91 ± 13% for EGF, +16 ± 4% for HGF, +11 ± 5% for FGF, +16 ± 9% for TGF-β1), and a greater release of EGF (85 ± 10%) in comparison with only the freezing process, because proteins become much readily solubilized in the solution. According with these results, we describe a protocol to obtain a new sterile biological product from hAM tissue, with well-known effects of thermal, mechanical and physical processes on the total protein and grow factors contents.

Low-temperature deposition manufacturing: A novel and promising rapid prototyping technology for the fabrication of tissue-engineered scaffold.

PubMed

Liu, Wei; Wang, Daming; Huang, Jianghong; Wei, You; Xiong, Jianyi; Zhu, Weimin; Duan, Li; Chen, Jielin; Sun, Rong; Wang, Daping

2017-01-01

Developed in recent years, low-temperature deposition manufacturing (LDM) represents one of the most promising rapid prototyping technologies. It is not only based on rapid deposition manufacturing process but also combined with phase separation process. Besides the controlled macropore size, tissue-engineered scaffold fabricated by LDM has inter-connected micropores in the deposited lines. More importantly, it is a green manufacturing process that involves non-heating liquefying of materials. It has been employed to fabricate tissue-engineered scaffolds for bone, cartilage, blood vessel and nerve tissue regenerations. It is a promising technology in the fabrication of tissue-engineered scaffold similar to ideal scaffold and the design of complex organs. In the current paper, this novel LDM technology is introduced, and its control parameters, biomedical applications and challenges are included and discussed as well. Copyright © 2016 Elsevier B.V. All rights reserved.

On the biomechanical function of scaffolds for engineering load-bearing soft tissues.

PubMed

Stella, John A; D'Amore, Antonio; Wagner, William R; Sacks, Michael S

2010-07-01

Replacement or regeneration of load-bearing soft tissues has long been the impetus for the development of bioactive materials. While maturing, current efforts continue to be confounded by our lack of understanding of the intricate multi-scale hierarchical arrangements and interactions typically found in native tissues. The current state of the art in biomaterial processing enables a degree of controllable microstructure that can be used for the development of model systems to deduce fundamental biological implications of matrix morphologies on cell function. Furthermore, the development of computational frameworks which allow for the simulation of experimentally derived observations represents a positive departure from what has mostly been an empirically driven field, enabling a deeper understanding of the highly complex biological mechanisms we wish to ultimately emulate. Ongoing research is actively pursuing new materials and processing methods to control material structure down to the micro-scale to sustain or improve cell viability, guide tissue growth, and provide mechanical integrity, all while exhibiting the capacity to degrade in a controlled manner. The purpose of this review is not to focus solely on material processing but to assess the ability of these techniques to produce mechanically sound tissue surrogates, highlight the unique structural characteristics produced in these materials, and discuss how this translates to distinct macroscopic biomechanical behaviors. Copyright 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Additive Manufacturing of Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/poly(ε-caprolactone) Blend Scaffolds for Tissue Engineering

PubMed Central

Puppi, Dario; Morelli, Andrea; Chiellini, Federica

2017-01-01

Additive manufacturing of scaffolds made of a polyhydroxyalkanoate blended with another biocompatible polymer represents a cost-effective strategy for combining the advantages of the two blend components in order to develop tailored tissue engineering approaches. The aim of this study was the development of novel poly(3-hydroxybutyrate-co-3-hydroxyhexanoate)/ poly(ε-caprolactone) (PHBHHx/PCL) blend scaffolds for tissue engineering by means of computer-aided wet-spinning, a hybrid additive manufacturing technique suitable for processing polyhydroxyalkanoates dissolved in organic solvents. The experimental conditions for processing tetrahydrofuran solutions containing the two polymers at different concentrations (PHBHHx/PCL weight ratio of 3:1, 2:1 or 1:1) were optimized in order to manufacture scaffolds with predefined geometry and internal porous architecture. PHBHHx/PCL scaffolds with a 3D interconnected network of macropores and a local microporosity of the polymeric matrix, as a consequence of the phase inversion process governing material solidification, were successfully fabricated. As shown by scanning electron microscopy, thermogravimetric, differential scanning calorimetric and uniaxial compressive analyses, blend composition significantly influenced the scaffold morphological, thermal and mechanical properties. In vitro biological characterization showed that the developed scaffolds were able to sustain the adhesion and proliferation of MC3T3-E1 murine preosteoblast cells. The additive manufacturing approach developed in this study, based on a polymeric solution processing method avoiding possible material degradation related to thermal treatments, could represent a powerful tool for the development of customized PHBHHx-based blend scaffolds for tissue engineering. PMID:28952527

Biomaterials-based 3D cell printing for next-generation therapeutics and diagnostics.

PubMed

Jang, Jinah; Park, Ju Young; Gao, Ge; Cho, Dong-Woo

2018-02-01

Building human tissues via 3D cell printing technology has received particular attention due to its process flexibility and versatility. This technology enables the recapitulation of unique features of human tissues and the all-in-one manufacturing process through the design of smart and advanced biomaterials and proper polymerization techniques. For the optimal engineering of tissues, a higher-order assembly of physiological components, including cells, biomaterials, and biomolecules, should meet the critical requirements for tissue morphogenesis and vascularization. The convergence of 3D cell printing with a microfluidic approach has led to a significant leap in the vascularization of engineering tissues. In addition, recent cutting-edge technology in stem cells and genetic engineering can potentially be adapted to the 3D tissue fabrication technique, and it has great potential to shift the paradigm of disease modeling and the study of unknown disease mechanisms required for precision medicine. This review gives an overview of recent developments in 3D cell printing and bioinks and provides technical requirements for engineering human tissues. Finally, we propose suggestions on the development of next-generation therapeutics and diagnostics. Copyright © 2017 Elsevier Ltd. All rights reserved.

Skeletogenesis in the swell shark Cephaloscyllium ventriosum

PubMed Central

Eames, B Frank; Allen, Nancy; Young, Jonathan; Kaplan, Angelo; Helms, Jill A; Schneider, Richard A

2007-01-01

Extant chondrichthyans possess a predominantly cartilaginous skeleton, even though primitive chondrichthyans produced bone. To gain insights into this peculiar skeletal evolution, and in particular to evaluate the extent to which chondrichthyan skeletogenesis retains features of an osteogenic programme, we performed a histological, histochemical and immunohistochemical analysis of the entire embryonic skeleton during development of the swell shark Cephaloscyllium ventriosum. Specifically, we compared staining properties among various mineralizing tissues, including neural arches of the vertebrae, dermal tissues supporting oral denticles and Meckel's cartilage of the lower jaw. Patterns of mineralization were predicted by spatially restricted alkaline phosphatase activity earlier in development. Regarding evidence for an osteogenic programme in extant sharks, a mineralized tissue in the perichondrium of C. ventriosum neural arches, and to a lesser extent a tissue supporting the oral denticle, displayed numerous properties of bone. Although we uncovered many differences between tissues in Meckel's cartilage and neural arches of C. ventriosum, both elements impart distinct tissue characteristics to the perichondral region. Considering the evolution of osteogenic processes, shark skeletogenesis may illuminate the transition from perichondrium to periosteum, which is a major bone-forming tissue during the process of endochondral ossification. PMID:17451531

Macrophages: development and tissue specialization.

PubMed

Varol, Chen; Mildner, Alexander; Jung, Steffen

2015-01-01

Macrophages are myeloid immune cells that are strategically positioned throughout the body tissues, where they ingest and degrade dead cells, debris, and foreign material and orchestrate inflammatory processes. Here we review two major recent paradigm shifts in our understanding of tissue macrophage biology. The first is the realization that most tissue-resident macrophages are established prenatally and maintained through adulthood by longevity and self-renewal. Their generation and maintenance are thus independent from ongoing hematopoiesis, although the cells can be complemented by adult monocyte-derived macrophages. Second, aside from being immune sentinels, tissue macrophages form integral components of their host tissue. This entails their specialization in response to local environmental cues to contribute to the development and specific function of their tissue of residence. Factors that govern tissue macrophage specialization are emerging. Moreover, tissue specialization is reflected in discrete gene expression profiles of macrophages, as well as epigenetic signatures reporting actual and potential enhancer usage.

Molecular and physiological mechanisms regulating tissue reunion in incised plant tissues.

PubMed

Asahina, Masashi; Satoh, Shinobu

2015-05-01

Interactions among the functionally specialized organs of higher plants ensure that the plant body develops and functions properly in response to changing environmental conditions. When an incision or grafting procedure interrupts the original organ or tissue connection, cell division is induced and tissue reunion occurs to restore physiological connections. Such activities have long been observed in grafting techniques, which are advantageous not only for agriculture and horticulture but also for basic research. To understand how this healing process is controlled and how this process is initiated and regulated at the molecular level, physiological and molecular analyses of tissue reunion have been performed using incised hypocotyls of cucumber (Cucumis sativus) and tomato (Solanum lycopersicum) and incised flowering stems of Arabidopsis thaliana. Our results suggest that leaf gibberellin and microelements from the roots are required for tissue reunion in the cortex of the cucumber and tomato incised hypocotyls. In addition, the wound-inducible hormones ethylene and jasmonic acid contribute to the regulation of the tissue reunion process in the upper and lower parts, respectively, of incised Arabidopsis stems. Ethylene and jasmonic acid modulate the expression of ANAC071 and RAP2.6L, respectively, and auxin signaling via ARF6/8 is essential for the expression of these transcription factors. In this report, we discuss recent findings regarding molecular and physiological mechanisms of the graft union and the tissue reunion process in wounded tissues of plants.

[Experimental-morphologic study of bone tissue reaction to carbon-containing material implantation with initiated X-ray contrast property].

PubMed

Grigorian, A S; Nabiev, F Kh; Golovin, R V

2005-01-01

In experimental study on 15 rabbits (chinchilla) influence of titanium plates implanted lapped on adjacent tissues in the region of the lower jaw body (comparison group) and carbon material with added boron in the concentrations of 8 and 15% (the study group) was studied. Results of the experimental-morphological investigation show that carbon-based materials with boron addition (with its content 8 and 15%) did not impede adaptive rebuilding of bone tissues and in particular bone structure regeneration in the process of reactive rebuilding of the "maternal" bone. Moreover, as the result of reactive processes developing in osseous tissues after implantation of the tested materials their successful integration in surrounding tissue structures was detected.

Motion compensation for in vivo subcellular optical microscopy.

PubMed

Lucotte, B; Balaban, R S

2014-04-01

In this review, we focus on the impact of tissue motion on attempting to conduct subcellular resolution optical microscopy, in vivo. Our position is that tissue motion is one of the major barriers in conducting these studies along with light induced damage, optical probe loading as well as absorbing and scattering effects on the excitation point spread function and collection of emitted light. Recent developments in the speed of image acquisition have reached the limit, in most cases, where the signal from a subcellular voxel limits the speed and not the scanning rate of the microscope. Different schemes for compensating for tissue displacements due to rigid body and deformation are presented from tissue restriction, gating, adaptive gating and active tissue tracking. We argue that methods that minimally impact the natural physiological motion of the tissue are desirable because the major reason to perform in vivo studies is to evaluate normal physiological functions. Towards this goal, active tracking using the optical imaging data itself to monitor tissue displacement and either prospectively or retrospectively correct for the motion without affecting physiological processes is desirable. Critical for this development was the implementation of near real time image processing in conjunction with the control of the microscope imaging parameters. Clearly, the continuing development of methods of motion compensation as well as significant technological solutions to the other barriers to tissue subcellular optical imaging in vivo, including optical aberrations and overall signal-to-noise ratio, will make major contributions to the understanding of cell biology within the body.

A review of cutting mechanics and modeling techniques for biological materials.

PubMed

Takabi, Behrouz; Tai, Bruce L

2017-07-01

This paper presents a comprehensive survey on the modeling of tissue cutting, including both soft tissue and bone cutting processes. In order to achieve higher accuracy in tissue cutting, as a critical process in surgical operations, the meticulous modeling of such processes is important in particular for surgical tool development and analysis. This review paper is focused on the mechanical concepts and modeling techniques utilized to simulate tissue cutting such as cutting forces and chip morphology. These models are presented in two major categories, namely soft tissue cutting and bone cutting. Fracture toughness is commonly used to describe tissue cutting while Johnson-Cook material model is often adopted for bone cutting in conjunction with finite element analysis (FEA). In each section, the most recent mathematical and computational models are summarized. The differences and similarities among these models, challenges, novel techniques, and recommendations for future work are discussed along with each section. This review is aimed to provide a broad and in-depth vision of the methods suitable for tissue and bone cutting simulations. Copyright © 2017 IPEM. Published by Elsevier Ltd. All rights reserved.

An evaluation of Admedus' tissue engineering process-treated (ADAPT) bovine pericardium patch (CardioCel) for the repair of cardiac and vascular defects.

PubMed

Strange, Geoff; Brizard, Christian; Karl, Tom R; Neethling, Leon

2015-03-01

Tissue engineers have been seeking the 'Holy Grail' solution to calcification and cytotoxicity of implanted tissue for decades. Tissues with all of the desired qualities for surgical repair of congenital heart disease (CHD) are lacking. An anti-calcification tissue engineering process (ADAPT TEP) has been developed and applied to bovine pericardium (BP) tissue (CardioCel, AdmedusRegen Pty Ltd, Perth, WA, Australia) to eliminate cytotoxicity, improve resistance to acute and chronic inflammation, reduce calcification and facilitate controlled tissue remodeling. Clinical data in pediatric patients, and additional pre-market authorized prescriber data demonstrate that CardioCel performs extremely well in the short term and is safe and effective for a range of congenital heart deformations. These data are supported by animal studies which have shown no more than normal physiologic levels of calcification, with good durability, biocompatibility and controlled healing.

Utilization of microgravity bioreactors for differentiation of mammalian skeletal tissue

NASA Technical Reports Server (NTRS)

Klement, B. J.; Spooner, B. S.

1993-01-01

Bioreactor cell and tissue culture vessels can be used to study bone development in a simulated microgravity environment. These vessels will also provide an advantageous, low maintenance culture system on space station Freedom. Although many types of cells and tissues can potentially utilize this system, our particular interest is in developing bone tissue. We have characterized an organ culture system utilizing embryonic mouse pre-metatarsal mesenchyme, documenting morphogenesis and differentiation as cartilage rods are formed, with subsequent terminal chondrocyte differentiation to hypertrophied cells. Further development to form bone tissue is achieved by supplementation of the culture medium. Research using pre-metatarsal tissue, combined with the bioreactor culture hardware, could give insight into the advantages and/or disadvantages of conditions experienced in microgravity. Studies such as these have the potential to enhance understanding of bone development and adult bone physiology, and may help define the processes of bone demineralization experienced in space and in pathological conditions here on earth.

Decoupling the effect of shear stress and stretch on tissue growth & remodeling in a vascular graft.

PubMed

van Haaften, Eline E; Wissing, Tamar B; Rutten, Marcel; Bulsink, Jurgen A; Gashi, Kujtim; van Kelle, Mathieu A J; Smits, Anthal; Bouten, Carlijn; Kurniawan, Nicholas A

2018-06-07

The success of cardiovascular tissue engineering strategies largely depends on the mechanical environment in which cells develop a neo-tissue via growth and remodeling processes. This mechanical environment is defined by the local scaffold architecture to which cells adhere, i.e., the micro-environment, and by external mechanical cues to which cells respond, i.e., hemodynamic loading. The hemodynamic environment of early-developing blood vessels consists of both shear stress (due to blood flow) and circumferential stretch (due to blood pressure). Experimental platforms that recapitulate this mechanical environment in a controlled and tunable manner are thus critical for investigating cardiovascular tissue engineering. In traditional perfusion bioreactors, however, shear stress and stretch are coupled, hampering a clear delineation of their effects on cell and tissue response. Here, we uniquely designed a bioreactor that independently combines these two types of mechanical cues in eight parallel vascular grafts. The system is computationally and experimentally validated, through finite element analysis and culture of tissue constructs respectively, to distinguish various levels of shear stress (up to 5 Pa) and cyclic stretch (up to 1.10). To illustrate the usefulness of the system, we investigated the relative contribution of cyclic stretch (1.05 at 0.5 Hz) and shear stress (1 Pa) to tissue development. Both types of hemodynamic loading contributed to cell alignment, but the contribution of shear stress overruled stretch-induced cell proliferation and matrix (i.e., collagen and glycosaminoglycan) production. At a macroscopic level, cyclic stretching led to the most linear stress-stretch response, which was not related to the presence of shear stress. In conclusion, we have developed a bioreactor that is particularly suited to further unravel the interplay between hemodynamics and in situ tissue engineering processes. Using the new system, the present work highlights the importance of hemodynamic loading to the study of developing vascular tissues.

The Celution® System: Automated Processing of Adipose-Derived Regenerative Cells in a Functionally Closed System.

PubMed

Fraser, John K; Hicok, Kevin C; Shanahan, Rob; Zhu, Min; Miller, Scott; Arm, Douglas M

2014-01-01

Objective: To develop a closed, automated system that standardizes the processing of human adipose tissue to obtain and concentrate regenerative cells suitable for clinical treatment of thermal and radioactive burn wounds. Approach: A medical device was designed to automate processing of adipose tissue to obtain a clinical-grade cell output of stromal vascular cells that may be used immediately as a therapy for a number of conditions, including nonhealing wounds resulting from radiation damage. Results: The Celution ® System reliably and reproducibly generated adipose-derived regenerative cells (ADRCs) from tissue collected manually and from three commercial power-assisted liposuction devices. The entire process of introducing tissue into the system, tissue washing and proteolytic digestion, isolation and concentration of the nonadipocyte nucleated cell fraction, and return to the patient as a wound therapeutic, can be achieved in approximately 1.5 h. An alternative approach that applies ultrasound energy in place of enzymatic digestion demonstrates extremely poor efficiency cell extraction. Innovation: The Celution System is the first medical device validated and approved by multiple international regulatory authorities to generate autologous stromal vascular cells from adipose tissue that can be used in a real-time bedside manner. Conclusion: Initial preclinical and clinical studies using ADRCs obtained using the automated tissue processing Celution device described herein validate a safe and effective manner to obtain a promising novel cell-based treatment for wound healing.

Tissue chips - innovative tools for drug development and disease modeling.

PubMed

Low, L A; Tagle, D A

2017-09-12

The high rate of failure during drug development is well-known, however recent advances in tissue engineering and microfabrication have contributed to the development of microphysiological systems (MPS), or 'organs-on-chips' that recapitulate the function of human organs. These 'tissue chips' could be utilized for drug screening and safety testing to potentially transform the early stages of the drug development process. They can also be used to model disease states, providing new tools for the understanding of disease mechanisms and pathologies, and assessing effectiveness of new therapies. In the future, they could be used to test new treatments and therapeutics in populations - via clinical trials-on-chips - and individuals, paving the way for precision medicine. Here we will discuss the wide-ranging and promising future of tissue chips, as well as challenges facing their development.

Distinct palisade tissue development processes promoted by leaf autonomous signalling and long-distance signalling in Arabidopsis thaliana.

PubMed

Munekage, Yuri Nakajima; Inoue, Shio; Yoneda, Yuki; Yokota, Akiho

2015-06-01

Plants develop palisade tissue consisting of cylindrical mesophyll cells located at the adaxial side of leaves in response to high light. To understand high light signalling in palisade tissue development, we investigated leaf autonomous and long-distance signal responses of palisade tissue development using Arabidopsis thaliana. Illumination of a developing leaf with high light induced cell height elongation, whereas illumination of mature leaves with high light increased cell density and suppressed cell width expansion in palisade tissue of new leaves. Examination using phototropin1 phototropin2 showed that blue light signalling mediated by phototropins was involved in cell height elongation of the leaf autonomous response rather than the cell density increase induced by long-distance signalling. Hydrogen peroxide treatment induced cylindrical palisade tissue cell formation in both a leaf autonomous and long-distance manner, suggesting involvement of oxidative signals. Although constitutive expression of transcription factors involved in systemic-acquired acclimation to excess light, ZAT10 and ZAT12, induced cylindrical palisade tissue cell formation, knockout of these genes did not affect cylindrical palisade tissue cell formation. We conclude that two distinct signalling pathways - leaf autonomous signalling mostly dependent on blue light signalling and long-distance signalling from mature leaves that sense high light and oxidative stress - control palisade tissue development in A. thaliana. © 2014 John Wiley & Sons Ltd.

Considerations in establishing a post-mortem brain and tissue bank for the study of myalgic encephalomyelitis/chronic fatigue syndrome: a proposed protocol.

PubMed

Nacul, Luis; O'Donovan, Dominic G; Lacerda, Eliana M; Gveric, Djordje; Goldring, Kirstin; Hall, Alison; Bowman, Erinna; Pheby, Derek

2014-06-18

Our aim, having previously investigated through a qualitative study involving extensive discussions with experts and patients the issues involved in establishing and maintaining a disease specific brain and tissue bank for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), was to develop a protocol for a UK ME/CFS repository of high quality human tissue from well characterised subjects with ME/CFS and controls suitable for a broad range of research applications. This would involve a specific donor program coupled with rapid tissue collection and processing, supplemented by comprehensive prospectively collected clinical, laboratory and self-assessment data from cases and controls. We reviewed the operations of existing tissue banks from published literature and from their internal protocols and standard operating procedures (SOPs). On this basis, we developed the protocol presented here, which was designed to meet high technical and ethical standards and legal requirements and was based on recommendations of the MRC UK Brain Banks Network. The facility would be most efficient and cost-effective if incorporated into an existing tissue bank. Tissue collection would be rapid and follow robust protocols to ensure preservation sufficient for a wide range of research uses. A central tissue bank would have resources both for wide-scale donor recruitment and rapid response to donor death for prompt harvesting and processing of tissue. An ME/CFS brain and tissue bank could be established using this protocol. Success would depend on careful consideration of logistic, technical, legal and ethical issues, continuous consultation with patients and the donor population, and a sustainable model of funding ideally involving research councils, health services, and patient charities. This initiative could revolutionise the understanding of this still poorly-understood disease and enhance development of diagnostic biomarkers and treatments.

[Morphological characteristics of kidneys connective tissue of mature fetuses and newborns from mothers, whose pregnancy was complicated by preeclampsia of varying degrees of severity].

PubMed

Sorokina, Iryna V; Myroshnychenko, Mykhailo S; Kapustnyk, Nataliia V; Khramova, Tetyana O; Dehtiarova, Oksana V; Danylchenko, Svitlana I

2018-01-01

Introduction: The kidneys connective tissue condition in the antenatal period affects the formation of tissues and it changes with the development of various general pathological processes in this organ. The aim of the study was to identify the morphological features of kidneys connective tissue of fetuses and newborns from mothers whose pregnancy was complicated by preeclampsia of varying degrees of severity. Materials and methods: The material of the study was the tissue of kidneys of mature fetuses and newborns from mothers with physiological pregnancy (28 cases), as well as from mothers whose pregnancy was complicated by preeclampsia of varying degrees of severity (78 cases). Immunohistochemical study was performed by an indirect Coons method according to M. Brosman's technique using monoclonal antibodies to collagen type I, III and IV. Results: The kidneys connective tissue of fetuses and newborns developing under the maternal preeclampsia conditions is characterized by the qualitative and quantitative changes that indicate the development of sclerotic processes in this organ, the severity of which increase with the age and with the increase of the maternal preeclampsia severity. Qualitative changes are characterized by an increase of the fibrous component, thickening of the bundles of connective tissue fibers, and a decrease in the distance between them. Quantitative changes are characterized by a pronounced predominance of collagen fibers over elastic fibers, almost total absence in some field of view elastic fibers and the violation of the content of collagen type I, III and IV. Conclusion: Maternal preeclampsia underlies the development of qualitative and quantitative changes in kidneys connective tissue of fetuses and newborns, which as a result will lead to disruption of the functions of these organs in such children.

Optimization and real-time control for laser treatment of heterogeneous soft tissues.

PubMed

Feng, Yusheng; Fuentes, David; Hawkins, Andrea; Bass, Jon M; Rylander, Marissa Nichole

2009-01-01

Predicting the outcome of thermotherapies in cancer treatment requires an accurate characterization of the bioheat transfer processes in soft tissues. Due to the biological and structural complexity of tumor (soft tissue) composition and vasculature, it is often very difficult to obtain reliable tissue properties that is one of the key factors for the accurate treatment outcome prediction. Efficient algorithms employing in vivo thermal measurements to determine heterogeneous thermal tissues properties in conjunction with a detailed sensitivity analysis can produce essential information for model development and optimal control. The goals of this paper are to present a general formulation of the bioheat transfer equation for heterogeneous soft tissues, review models and algorithms developed for cell damage, heat shock proteins, and soft tissues with nanoparticle inclusion, and demonstrate an overall computational strategy for developing a laser treatment framework with the ability to perform real-time robust calibrations and optimal control. This computational strategy can be applied to other thermotherapies using the heat source such as radio frequency or high intensity focused ultrasound.

Endochondral Priming: A Developmental Engineering Strategy for Bone Tissue Regeneration.

PubMed

Freeman, Fiona E; McNamara, Laoise M

2017-04-01

Tissue engineering and regenerative medicine have significant potential to treat bone pathologies by exploiting the capacity for bone progenitors to grow and produce tissue constituents under specific biochemical and physical conditions. However, conventional tissue engineering approaches, which combine stem cells with biomaterial scaffolds, are limited as the constructs often degrade, due to a lack of vascularization, and lack the mechanical integrity to fulfill load bearing functions, and as such are not yet widely used for clinical treatment of large bone defects. Recent studies have proposed that in vitro tissue engineering approaches should strive to simulate in vivo bone developmental processes and, thereby, imitate natural factors governing cell differentiation and matrix production, following the paradigm recently defined as "developmental engineering." Although developmental engineering strategies have been recently developed that mimic specific aspects of the endochondral ossification bone formation process, these findings are not widely understood. Moreover, a critical comparison of these approaches to standard biomaterial-based bone tissue engineering has not yet been undertaken. For that reason, this article presents noteworthy experimental findings from researchers focusing on developing an endochondral-based developmental engineering strategy for bone tissue regeneration. These studies have established that in vitro approaches, which mimic certain aspects of the endochondral ossification process, namely the formation of the cartilage template and the vascularization of the cartilage template, can promote mineralization and vascularization to a certain extent both in vitro and in vivo. Finally, this article outlines specific experimental challenges that must be overcome to further exploit the biology of endochondral ossification and provide a tissue engineering construct for clinical treatment of large bone/nonunion defects and obviate the need for bone tissue graft.

Identification of Novel Tissue-Specific Genes by Analysis of Microarray Databases: A Human and Mouse Model

PubMed Central

Suh, Yeunsu; Davis, Michael E.; Lee, Kichoon

2013-01-01

Understanding the tissue-specific pattern of gene expression is critical in elucidating the molecular mechanisms of tissue development, gene function, and transcriptional regulations of biological processes. Although tissue-specific gene expression information is available in several databases, follow-up strategies to integrate and use these data are limited. The objective of the current study was to identify and evaluate novel tissue-specific genes in human and mouse tissues by performing comparative microarray database analysis and semi-quantitative PCR analysis. We developed a powerful approach to predict tissue-specific genes by analyzing existing microarray data from the NCBI′s Gene Expression Omnibus (GEO) public repository. We investigated and confirmed tissue-specific gene expression in the human and mouse kidney, liver, lung, heart, muscle, and adipose tissue. Applying our novel comparative microarray approach, we confirmed 10 kidney, 11 liver, 11 lung, 11 heart, 8 muscle, and 8 adipose specific genes. The accuracy of this approach was further verified by employing semi-quantitative PCR reaction and by searching for gene function information in existing publications. Three novel tissue-specific genes were discovered by this approach including AMDHD1 (amidohydrolase domain containing 1) in the liver, PRUNE2 (prune homolog 2) in the heart, and ACVR1C (activin A receptor, type IC) in adipose tissue. We further confirmed the tissue-specific expression of these 3 novel genes by real-time PCR. Among them, ACVR1C is adipose tissue-specific and adipocyte-specific in adipose tissue, and can be used as an adipocyte developmental marker. From GEO profiles, we predicted the processes in which AMDHD1 and PRUNE2 may participate. Our approach provides a novel way to identify new sets of tissue-specific genes and to predict functions in which they may be involved. PMID:23741331

(n-3) Fatty Acids Alleviate Adipose Tissue Inflammation and Insulin Resistance: Mechanistic Insights12

PubMed Central

Kalupahana, Nishan S.; Claycombe, Kate J.; Moustaid-Moussa, Naima

2011-01-01

Obesity is associated with the metabolic syndrome, a significant risk factor for developing type 2 diabetes and cardiovascular diseases. Chronic low-grade inflammation occurring in the adipose tissue of obese individuals is causally linked to the pathogenesis of insulin resistance and the metabolic syndrome. Although the exact trigger of this inflammatory process is unknown, adipose tissue hypoxia, endoplasmic reticular stress, and saturated fatty acid–mediated activation of innate immune processes have been identified as important processes in these disorders. Furthermore, macrophages and T lymphocytes have important roles in orchestrating this immune process. Although energy restriction leading to weight loss is the primary dietary intervention to reverse these obesity-associated metabolic disorders, other interventions targeted at alleviating adipose tissue inflammation have not been explored in detail. In this regard, (n-3) PUFA of marine origin both prevent and reverse high-fat-diet–induced adipose tissue inflammation and insulin resistance in rodents. We provide an update on the pathogenesis of adipose tissue inflammation and insulin resistance in obesity and discuss potential mechanisms by which (n-3) PUFA prevent and reverse these changes and the implications in human health. PMID:22332072

Multi-scale heat and mass transfer modelling of cell and tissue cryopreservation

PubMed Central

Xu, Feng; Moon, Sangjun; Zhang, Xiaohui; Shao, Lei; Song, Young Seok; Demirci, Utkan

2010-01-01

Cells and tissues undergo complex physical processes during cryopreservation. Understanding the underlying physical phenomena is critical to improve current cryopreservation methods and to develop new techniques. Here, we describe multi-scale approaches for modelling cell and tissue cryopreservation including heat transfer at macroscale level, crystallization, cell volume change and mass transport across cell membranes at microscale level. These multi-scale approaches allow us to study cell and tissue cryopreservation. PMID:20047939

Combining polarimetry and spectropolarimetry techniques in diagnostics of cancer changes in biological tissues

NASA Astrophysics Data System (ADS)

Yermolenko, Sergey; Ivashko, Pavlo; Gruia, Ion; Gruia, Maria; Peresunko, Olexander; Zelinska, Natalia; Voloshynskyi, Dmytro; Fedoruk, Olexander; Zimnyakov, Dmitry; Alonova, Marina

2015-02-01

The aim of the study is combining polarimetry and spectropolarimetry techniques for identifying the changes of opticalgeometrical structure in different kinds of biotissues with solid tumours. It is researched that a linear dichroism appears in biotissues (human esophagus, muscle tissue of rats, human prostate tissue, cervical smear) with cancer diseases, magnitude of which depends on the type of the tissue and on the time of cancer process development.

Direct Hydrogel Encapsulation of Pluripotent Stem Cells Enables Ontomimetic Differentiation and Growth of Engineered Human Heart Tissues

PubMed Central

Kerscher, Petra; Turnbull, Irene C; Hodge, Alexander J; Kim, Joonyul; Seliktar, Dror; Easley, Christopher J; Costa, Kevin D; Lipke, Elizabeth A

2016-01-01

Human engineered heart tissues have potential to revolutionize cardiac development research, drug-testing, and treatment of heart disease; however, implementation is limited by the need to use pre-differentiated cardiomyocytes (CMs). Here we show that by providing a 3D poly(ethylene glycol)-fibrinogen hydrogel microenvironment, we can directly differentiate human pluripotent stem cells (hPSCs) into contracting heart tissues. Our straight-forward, ontomimetic approach, imitating the process of development, requires only a single cell-handling step, provides reproducible results for a range of tested geometries and size scales, and overcomes inherent limitations in cell maintenance and maturation, while achieving high yields of CMs with developmentally appropriate temporal changes in gene expression. Here we demonstrate that hPSCs encapsulated within this biomimetic 3D hydrogel microenvironment develop into functional cardiac tissues composed of self-aligned CMs with evidence of ultrastructural maturation, mimicking heart development, and enabling investigation of disease mechanisms and screening of compounds on developing human heart tissue. PMID:26826618

Models and signal processing for an implanted ethanol bio-sensor.

PubMed

Han, Jae-Joon; Doerschuk, Peter C; Gelfand, Saul B; O'Connor, Sean J

2008-02-01

The understanding of drinking patterns leading to alcoholism has been hindered by an inability to unobtrusively measure ethanol consumption over periods of weeks to months in the community environment. An implantable ethanol sensor is under development using microelectromechanical systems technology. For safety and user acceptability issues, the sensor will be implanted subcutaneously and, therefore, measure peripheral-tissue ethanol concentration. Determining ethanol consumption and kinetics in other compartments from the time course of peripheral-tissue ethanol concentration requires sophisticated signal processing based on detailed descriptions of the relevant physiology. A statistical signal processing system based on detailed models of the physiology and using extended Kalman filtering and dynamic programming tools is described which can estimate the time series of ethanol concentration in blood, liver, and peripheral tissue and the time series of ethanol consumption based on peripheral-tissue ethanol concentration measurements.

A review of evolution of electrospun tissue engineering scaffold: From two dimensions to three dimensions.

PubMed

Ngadiman, Nor Hasrul Akhmal; Noordin, M Y; Idris, Ani; Kurniawan, Denni

2017-07-01

The potential of electrospinning process to fabricate ultrafine fibers as building blocks for tissue engineering scaffolds is well recognized. The scaffold construct produced by electrospinning process depends on the quality of the fibers. In electrospinning, material selection and parameter setting are among many factors that contribute to the quality of the ultrafine fibers, which eventually determine the performance of the tissue engineering scaffolds. The major challenge of conventional electrospun scaffolds is the nature of electrospinning process which can only produce two-dimensional electrospun mats, hence limiting their applications. Researchers have started to focus on overcoming this limitation by combining electrospinning with other techniques to fabricate three-dimensional scaffold constructs. This article reviews various polymeric materials and their composites/blends that have been successfully electrospun for tissue engineering scaffolds, their mechanical properties, and the various parameters settings that influence the fiber morphology. This review also highlights the secondary processes to electrospinning that have been used to develop three-dimensional tissue engineering scaffolds as well as the steps undertaken to overcome electrospinning limitations.

Porcine Tissue-Specific Regulatory Networks Derived from Meta-Analysis of the Transcriptome

PubMed Central

Pérez-Montarelo, Dafne; Hudson, Nicholas J.; Fernández, Ana I.; Ramayo-Caldas, Yuliaxis; Dalrymple, Brian P.; Reverter, Antonio

2012-01-01

The processes that drive tissue identity and differentiation remain unclear for most tissue types. So are the gene networks and transcription factors (TF) responsible for the differential structure and function of each particular tissue, and this is particularly true for non model species with incomplete genomic resources. To better understand the regulation of genes responsible for tissue identity in pigs, we have inferred regulatory networks from a meta-analysis of 20 gene expression studies spanning 480 Porcine Affymetrix chips for 134 experimental conditions on 27 distinct tissues. We developed a mixed-model normalization approach with a covariance structure that accommodated the disparity in the origin of the individual studies, and obtained the normalized expression of 12,320 genes across the 27 tissues. Using this resource, we constructed a network, based on the co-expression patterns of 1,072 TF and 1,232 tissue specific genes. The resulting network is consistent with the known biology of tissue development. Within the network, genes clustered by tissue and tissues clustered by site of embryonic origin. These clusters were significantly enriched for genes annotated in key relevant biological processes and confirm gene functions and interactions from the literature. We implemented a Regulatory Impact Factor (RIF) metric to identify the key regulators in skeletal muscle and tissues from the central nervous systems. The normalization of the meta-analysis, the inference of the gene co-expression network and the RIF metric, operated synergistically towards a successful search for tissue-specific regulators. Novel among these findings are evidence suggesting a novel key role of ERCC3 as a muscle regulator. Together, our results recapitulate the known biology behind tissue specificity and provide new valuable insights in a less studied but valuable model species. PMID:23049964

Media Compositions for Three Dimensional Mammalian Tissue Growth Under Microgravity Culture Conditions

NASA Technical Reports Server (NTRS)

Goodwin, Thomas J. (Inventor)

1998-01-01

Normal mammalian tissue and the culturing process has been developed for the three groups of organ, structural and blood tissue. The cells are grown in vitro under microgravity culture conditions and form three dimensional cells aggregates with normal cell function. The microgravity culture conditions may be microgravity or simulated microgravity created in a horizontal rotating wall culture vessel.

Media Compositions for Three-Dimensional Mammalian Tissue Growth under Microgravity Culture Conditions

NASA Technical Reports Server (NTRS)

Goodwin, Thomas J. (Inventor)

1998-01-01

Normal mammalian tissue and the culturing process has been developed for the three groups of organ, structural and blood tissue.The cells are grown in vitro under microgravity culture conditions and form three dimensional cells aggregates with normal cell function. The microgravity culture conditions may be microgravity or simulated microgravity created in a horizontal rotating wall culture vessel.

International perspectives on the ethics and regulation of human cell and tissue transplantation.

PubMed

Schulz-Baldes, Annette; Biller-Andorno, Nikola; Capron, Alexander Morgan

2007-12-01

The transplantation of human cells and tissues has become a global enterprise for both life-saving and life-enhancing purposes. Yet current practices raise numerous ethical and policy issues relating to informed consent for donation, profit-making, and quality and safety in the procurement, processing, distribution, and international circulation of human cells and tissues. This paper reports on recent developments in the international debate surrounding these issues, and in particular on the attention cell and tissue transplantation has received in WHO's ongoing process of updating its 1991 Guiding principles on human organ transplantation. Several of the organizers of an international working group of stakeholders from a wide range of backgrounds that convened in Zurich in July 2006 summarize the areas of normative agreement and disagreement, and identify open questions regarding facts and fundamental concepts of potential normative significance. These issues must be addressed through development of common medical, scientific, legal and ethical requirements for human cell and tissue transplantation on a global basis. While guidance must accommodate the distinct ethical issues raised by activities involving human cells and tissues, consistency with normative frameworks for organ transplantation remains a prime objective.

Large-scale inference of protein tissue origin in gram-positive sepsis plasma using quantitative targeted proteomics

PubMed Central

Malmström, Erik; Kilsgård, Ola; Hauri, Simon; Smeds, Emanuel; Herwald, Heiko; Malmström, Lars; Malmström, Johan

2016-01-01

The plasma proteome is highly dynamic and variable, composed of proteins derived from surrounding tissues and cells. To investigate the complex processes that control the composition of the plasma proteome, we developed a mass spectrometry-based proteomics strategy to infer the origin of proteins detected in murine plasma. The strategy relies on the construction of a comprehensive protein tissue atlas from cells and highly vascularized organs using shotgun mass spectrometry. The protein tissue atlas was transformed to a spectral library for highly reproducible quantification of tissue-specific proteins directly in plasma using SWATH-like data-independent mass spectrometry analysis. We show that the method can determine drastic changes of tissue-specific protein profiles in blood plasma from mouse animal models with sepsis. The strategy can be extended to several other species advancing our understanding of the complex processes that contribute to the plasma proteome dynamics. PMID:26732734

3D patterned stem cell differentiation using thermo-responsive methylcellulose hydrogel molds.

PubMed

Lee, Wonjae; Park, Jon

2016-07-06

Tissue-specific patterned stem cell differentiation serves as the basis for the development, remodeling, and regeneration of the multicellular structure of the native tissues. We herein proposed a cytocompatible 3D casting process to recapitulate this patterned stem cell differentiation for reconstructing multicellular tissues in vitro. We first reconstituted the 2D culture conditions for stem cell fate control within 3D hydrogel by incorporating the sets of the diffusible signal molecules delivered through drug-releasing microparticles. Then, utilizing thermo-responsivity of methylcellulose (MC), we developed a cytocompatible casting process to mold these hydrogels into specific 3D configurations, generating the targeted spatial gradients of diffusible signal molecules. The liquid phase of the MC solution was viscous enough to adopt the shapes of 3D impression patterns, while the gelated MC served as a reliable mold for patterning the hydrogel prepolymers. When these patterned hydrogels were integrated together, the stem cells in each hydrogel distinctly differentiated toward individually defined fates, resulting in the formation of the multicellular tissue structure bearing the very structural integrity and characteristics as seen in vascularized bones and osteochondral tissues.

3D patterned stem cell differentiation using thermo-responsive methylcellulose hydrogel molds

NASA Astrophysics Data System (ADS)

Lee, Wonjae; Park, Jon

2016-07-01

Tissue-specific patterned stem cell differentiation serves as the basis for the development, remodeling, and regeneration of the multicellular structure of the native tissues. We herein proposed a cytocompatible 3D casting process to recapitulate this patterned stem cell differentiation for reconstructing multicellular tissues in vitro. We first reconstituted the 2D culture conditions for stem cell fate control within 3D hydrogel by incorporating the sets of the diffusible signal molecules delivered through drug-releasing microparticles. Then, utilizing thermo-responsivity of methylcellulose (MC), we developed a cytocompatible casting process to mold these hydrogels into specific 3D configurations, generating the targeted spatial gradients of diffusible signal molecules. The liquid phase of the MC solution was viscous enough to adopt the shapes of 3D impression patterns, while the gelated MC served as a reliable mold for patterning the hydrogel prepolymers. When these patterned hydrogels were integrated together, the stem cells in each hydrogel distinctly differentiated toward individually defined fates, resulting in the formation of the multicellular tissue structure bearing the very structural integrity and characteristics as seen in vascularized bones and osteochondral tissues.

Sensing in tissue bioreactors

NASA Astrophysics Data System (ADS)

Rolfe, P.

2006-03-01

Specialized sensing and measurement instruments are under development to aid the controlled culture of cells in bioreactors for the fabrication of biological tissues. Precisely defined physical and chemical conditions are needed for the correct culture of the many cell-tissue types now being studied, including chondrocytes (cartilage), vascular endothelial cells and smooth muscle cells (blood vessels), fibroblasts, hepatocytes (liver) and receptor neurones. Cell and tissue culture processes are dynamic and therefore, optimal control requires monitoring of the key process variables. Chemical and physical sensing is approached in this paper with the aim of enabling automatic optimal control, based on classical cell growth models, to be achieved. Non-invasive sensing is performed via the bioreactor wall, invasive sensing with probes placed inside the cell culture chamber and indirect monitoring using analysis within a shunt or a sampling chamber. Electroanalytical and photonics-based systems are described. Chemical sensing for gases, ions, metabolites, certain hormones and proteins, is under development. Spectroscopic analysis of the culture medium is used for measurement of glucose and for proteins that are markers of cell biosynthetic behaviour. Optical interrogation of cells and tissues is also investigated for structural analysis based on scatter.

3D patterned stem cell differentiation using thermo-responsive methylcellulose hydrogel molds

PubMed Central

Lee, Wonjae; Park, Jon

2016-01-01

Tissue-specific patterned stem cell differentiation serves as the basis for the development, remodeling, and regeneration of the multicellular structure of the native tissues. We herein proposed a cytocompatible 3D casting process to recapitulate this patterned stem cell differentiation for reconstructing multicellular tissues in vitro. We first reconstituted the 2D culture conditions for stem cell fate control within 3D hydrogel by incorporating the sets of the diffusible signal molecules delivered through drug-releasing microparticles. Then, utilizing thermo-responsivity of methylcellulose (MC), we developed a cytocompatible casting process to mold these hydrogels into specific 3D configurations, generating the targeted spatial gradients of diffusible signal molecules. The liquid phase of the MC solution was viscous enough to adopt the shapes of 3D impression patterns, while the gelated MC served as a reliable mold for patterning the hydrogel prepolymers. When these patterned hydrogels were integrated together, the stem cells in each hydrogel distinctly differentiated toward individually defined fates, resulting in the formation of the multicellular tissue structure bearing the very structural integrity and characteristics as seen in vascularized bones and osteochondral tissues. PMID:27381562

Standard terminology and labeling of ocular tissue for transplantation.

PubMed

Armitage, W John; Ashford, Paul; Crow, Barbara; Dahl, Patricia; DeMatteo, Jennifer; Distler, Pat; Gopinathan, Usha; Madden, Peter W; Mannis, Mark J; Moffatt, S Louise; Ponzin, Diego; Tan, Donald

2013-06-01

To develop an internationally agreed terminology for describing ocular tissue grafts to improve the accuracy and reliability of information transfer, to enhance tissue traceability, and to facilitate the gathering of comparative global activity data, including denominator data for use in biovigilance analyses. ICCBBA, the international standards organization for terminology, coding, and labeling of blood, cells, and tissues, approached the major Eye Bank Associations to form an expert advisory group. The group met by regular conference calls to develop a standard terminology, which was released for public consultation and amended accordingly. The terminology uses broad definitions (Classes) with modifying characteristics (Attributes) to define each ocular tissue product. The terminology may be used within the ISBT 128 system to label tissue products with standardized bar codes enabling the electronic capture of critical data in the collection, processing, and distribution of tissues. Guidance on coding and labeling has also been developed. The development of a standard terminology for ocular tissue marks an important step for improving traceability and reducing the risk of mistakes due to transcription errors. ISBT 128 computer codes have been assigned and may now be used to label ocular tissues. Eye banks are encouraged to adopt this standard terminology and move toward full implementation of ISBT 128 nomenclature, coding, and labeling.

Fatigue Damage of Collagenous Tissues: Experiment, Modeling and Simulation Studies

PubMed Central

Martin, Caitlin; Sun, Wei

2017-01-01

Mechanical fatigue damage is a critical issue for soft tissues and tissue-derived materials, particularly for musculoskeletal and cardiovascular applications; yet, our understanding of the fatigue damage process is incomplete. Soft tissue fatigue experiments are often difficult and time-consuming to perform, which has hindered progress in this area. However, the recent development of soft-tissue fatigue-damage constitutive models has enabled simulation-based fatigue analyses of tissues under various conditions. Computational simulations facilitate highly controlled and quantitative analyses to study the distinct effects of various loading conditions and design features on tissue durability; thus, they are advantageous over complex fatigue experiments. Although significant work to calibrate the constitutive models from fatigue experiments and to validate predictability remains, further development in these areas will add to our knowledge of soft-tissue fatigue damage and will facilitate the design of durable treatments and devices. In this review, the experimental, modeling, and simulation efforts to study collagenous tissue fatigue damage are summarized and critically assessed. PMID:25955007

The magnitude of linear dichroism of biological tissues as a result of cancer changes

NASA Astrophysics Data System (ADS)

Bojchuk, T. M.; Yermolenko, S. B.; Fedonyuk, L. Y.; Petryshen, O. I.; Guminetsky, S. G.; Prydij, O. G.

2012-01-01

The results of studies of linear dichroism values of different types of biological tissues (human prostate, esophageal epithelial human muscle tissue in rats) both healthy and infected tumor at different stages of development are shown here. The significant differences in magnitude of linear dichroism and its spectral dependence in the spectral range λ = 330 - 750 nm both among the objects of study, and between biotissues: healthy (or affected by benign tumors) and cancer patients are established. It is researched that in all cases in biological tissues (prostate gland, esophagus, human muscle tissue in rats) with cancer the linear dichroism arises, the value of which depends on the type of tissue and time of the tumor process. As for healthy tissues linear dichroism is absent, the results may have diagnostic value for detecting and assessing the degree of development of cancer.

The magnitude of linear dichroism of biological tissues as a result of cancer changes

NASA Astrophysics Data System (ADS)

Bojchuk, T. M.; Yermolenko, S. B.; Fedonyuk, L. Y.; Petryshen, O. I.; Guminetsky, S. G.; Prydij, O. G.

2011-09-01

The results of studies of linear dichroism values of different types of biological tissues (human prostate, esophageal epithelial human muscle tissue in rats) both healthy and infected tumor at different stages of development are shown here. The significant differences in magnitude of linear dichroism and its spectral dependence in the spectral range λ = 330 - 750 nm both among the objects of study, and between biotissues: healthy (or affected by benign tumors) and cancer patients are established. It is researched that in all cases in biological tissues (prostate gland, esophagus, human muscle tissue in rats) with cancer the linear dichroism arises, the value of which depends on the type of tissue and time of the tumor process. As for healthy tissues linear dichroism is absent, the results may have diagnostic value for detecting and assessing the degree of development of cancer.

[Mathematic analysis of risk factors influence on occupational respiratory diseases development].

PubMed

Budkar', L N; Bugaeva, I V; Obukhova, T Iu; Tereshina, L G; Karpova, E A; Shmonina, O G

2010-01-01

Analysis covered 1348 case histories of workers exposed to industrial dust in Urals region. The analysis applied mathematical processing of survival theory and correlation analysis. The authors studied influence of various factors: dust concentration, connective tissue dysplasia, smoking habits--on duration for diseases caused by dust to appear. Findings are that occupational diseases develop reliably faster with higher ambient dust concentrations and with connective tissue dysplasia syndrome. Smoking habits do not alter duration of pneumoconiosis development, but reliably increases development of occupational dust bronchitis.

Quantitative analysis of tissue deformation dynamics reveals three characteristic growth modes and globally aligned anisotropic tissue deformation during chick limb development.

PubMed

Morishita, Yoshihiro; Kuroiwa, Atsushi; Suzuki, Takayuki

2015-05-01

Tissue-level characterization of deformation dynamics is crucial for understanding organ morphogenetic mechanisms, especially the interhierarchical links among molecular activities, cellular behaviors and tissue/organ morphogenetic processes. Limb development is a well-studied topic in vertebrate organogenesis. Nevertheless, there is still little understanding of tissue-level deformation relative to molecular and cellular dynamics. This is mainly because live recording of detailed cell behaviors in whole tissues is technically difficult. To overcome this limitation, by applying a recently developed Bayesian approach, we here constructed tissue deformation maps for chick limb development with high precision, based on snapshot lineage tracing using dye injection. The precision of the constructed maps was validated with a clear statistical criterion. From the geometrical analysis of the map, we identified three characteristic tissue growth modes in the limb and showed that they are consistent with local growth factor activity and cell cycle length. In particular, we report that SHH signaling activity changes dynamically with developmental stage and strongly correlates with the dynamic shift in the tissue growth mode. We also found anisotropic tissue deformation along the proximal-distal axis. Morphogenetic simulation and experimental studies suggested that this directional tissue elongation, and not local growth, has the greatest impact on limb shaping. This result was supported by the novel finding that anisotropic tissue elongation along the proximal-distal axis occurs independently of cell proliferation. Our study marks a pivotal point for multi-scale system understanding in vertebrate development. © 2015. Published by The Company of Biologists Ltd.

Surgical stapling device-tissue interactions: what surgeons need to know to improve patient outcomes.

PubMed

Chekan, Edward; Whelan, Richard L

2014-01-01

The introduction of both new surgical devices and reengineered existing devices leads to modifications in the way traditional tasks are carried out and allows for the development of new surgical techniques. Each new device has benefits and limitations in regards to tissue interactions that, if known, allow for optimal use. However, most surgeons are unaware of these attributes and, therefore, new device introduction creates a "knowledge gap" that is potentially dangerous. The goal of this review is to present a framework for the study of device- tissue interactions and to initiate the process of "filling in" the knowledge gap via the available literature. Surgical staplers, which are continually being developed, are the focus of this piece. The integrity of the staple line, which depends on adequate tissue compression, is the primary factor in creating a stable anastomosis. This review focuses on published studies that evaluated the creation of stable anastomoses in bariatric, thoracic, and colorectal procedures. Understanding how staplers interact with target tissues is key to improving patient outcomes. It is clear from this review that each tissue type presents unique challenges. The thickness of each tissue varies as do the intrinsic biomechanical properties that determine the ideal compressive force and prefiring compression time for each tissue type. The correct staple height will vary depending on these tissue-specific properties and the tissue pathology. These studies reinforce the universal theme that compression, staple height, tissue thickness, tissue compressibility, and tissue type must all be considered by the surgeon prior to choosing a stapler and cartridge. The surgeon's experience, therefore, is a critical factor. Educational programs need to be established to inform and update surgeons on the characteristics of each stapler. It is hoped that the framework presented in this review will facilitate this process.

CHARACTERIZATION OF AORTIC TISSUE CUTTING PROCESS: EXPERIMENTAL INVESTIGATION USING PORCINE ASCENDING AORTA

PubMed Central

Hu, Zhongwei; Sun, Wei; Zhang, Bi

2012-01-01

Understanding biomechanical responses during soft tissue cutting is important for developing surgical simulators and robot-assisted surgery with haptic feedback. The biomechanics involved in the aortic tissue cutting process is largely unknown. In this study, porcine ascending aorta was selected as a representative aortic tissue, and tissue cutting experiments were performed using a novel tissue cutting apparatus. The tissue cutting responses under various cutting conditions were investigated, including differing initial tissue lateral holding force and distance, cutting speed, cutter inclination angle, tissue anatomical orientation and thickness. The results from this study suggest that a “break-in” cutting force of about 4 – 12 N, a cutter “break-in” distance of 5 – 15 mm, and a continuous cutting force of 2 – 4 N were needed to cut through the porcine ascending aorta tissue. For all testing conditions investigated in this study, the cutting force vs. the cutter displacement curves exhibited similar characteristics. More importantly, this study demonstrated that tissue cutting involving one or more of the following conditions: a larger lateral holding force, a smaller lateral hold distance, a higher cutting speed or a larger inclination angle, could result in a smaller “break in” cutting force and a smaller “break-in” distance. In addition, it was found that the cutting force in the vessel longitudinal direction was larger than that in the circumferential direction. There was a strong correlation between the tissue thickness and the cutting force. The experimental results reported in this study could provide a basis for understanding the characteristic response of aortic tissue to scalpel cutting, and offer insight into the development of surgical simulators. PMID:23262306

3D surface reconstruction and visualization of the Drosophila wing imaginal disc at cellular resolution

NASA Astrophysics Data System (ADS)

Bai, Linge; Widmann, Thomas; Jülicher, Frank; Dahmann, Christian; Breen, David

2013-01-01

Quantifying and visualizing the shape of developing biological tissues provide information about the morphogenetic processes in multicellular organisms. The size and shape of biological tissues depend on the number, size, shape, and arrangement of the constituting cells. To better understand the mechanisms that guide tissues into their final shape, it is important to investigate the cellular arrangement within tissues. Here we present a data processing pipeline to generate 3D volumetric surface models of epithelial tissues, as well as geometric descriptions of the tissues' apical cell cross-sections. The data processing pipeline includes image acquisition, editing, processing and analysis, 2D cell mesh generation, 3D contourbased surface reconstruction, cell mesh projection, followed by geometric calculations and color-based visualization of morphological parameters. In their first utilization we have applied these procedures to construct a 3D volumetric surface model at cellular resolution of the wing imaginal disc of Drosophila melanogaster. The ultimate goal of the reported effort is to produce tools for the creation of detailed 3D geometric models of the individual cells in epithelial tissues. To date, 3D volumetric surface models of the whole wing imaginal disc have been created, and the apicolateral cell boundaries have been identified, allowing for the calculation and visualization of cell parameters, e.g. apical cross-sectional area of cells. The calculation and visualization of morphological parameters show position-dependent patterns of cell shape in the wing imaginal disc. Our procedures should offer a general data processing pipeline for the construction of 3D volumetric surface models of a wide variety of epithelial tissues.

The Celution® System: Automated Processing of Adipose-Derived Regenerative Cells in a Functionally Closed System

PubMed Central

Fraser, John K.; Hicok, Kevin C.; Shanahan, Rob; Zhu, Min; Miller, Scott; Arm, Douglas M.

2014-01-01

Objective: To develop a closed, automated system that standardizes the processing of human adipose tissue to obtain and concentrate regenerative cells suitable for clinical treatment of thermal and radioactive burn wounds. Approach: A medical device was designed to automate processing of adipose tissue to obtain a clinical-grade cell output of stromal vascular cells that may be used immediately as a therapy for a number of conditions, including nonhealing wounds resulting from radiation damage. Results: The Celution® System reliably and reproducibly generated adipose-derived regenerative cells (ADRCs) from tissue collected manually and from three commercial power-assisted liposuction devices. The entire process of introducing tissue into the system, tissue washing and proteolytic digestion, isolation and concentration of the nonadipocyte nucleated cell fraction, and return to the patient as a wound therapeutic, can be achieved in approximately 1.5 h. An alternative approach that applies ultrasound energy in place of enzymatic digestion demonstrates extremely poor efficiency cell extraction. Innovation: The Celution System is the first medical device validated and approved by multiple international regulatory authorities to generate autologous stromal vascular cells from adipose tissue that can be used in a real-time bedside manner. Conclusion: Initial preclinical and clinical studies using ADRCs obtained using the automated tissue processing Celution device described herein validate a safe and effective manner to obtain a promising novel cell-based treatment for wound healing. PMID:24761343

Purity and the dangers of regenerative medicine: regulatory innovation of human tissue-engineered technology.

PubMed

Faulkner, Alex; Kent, Julie; Geesink, Ingrid; FitzPatrick, David

2006-11-01

This paper examines the development of innovation in human tissue technologies as a form of regenerative medicine, firstly by applying 'pollution ideas' to contemporary trends in its risk regulation and to the processes of regulatory policy formation, and secondly by analysing the classificatory processes deployed in regulatory policy. The analysis draws upon data from fieldwork and documentary materials with a focus on the UK and EU (2002-05) and explores four arenas: governance and regulatory policy; commercialisation and the market; 'evidentiality' manifest in evidence-based policy; and publics' and technology users' values and ethics. The analysis suggests that there is a trend toward 'purification' across these arenas, both material and socio-political. A common process of partitioning is found in stakeholders' attempts to define a clear terrain, which the field of tissue-engineered technology might occupy. We conclude that pollution ideas and partitioning processes are useful in understanding regulatory ordering and innovation in the emerging technological zone of human tissue engineering.

A mechano-biological model of multi-tissue evolution in bone

NASA Astrophysics Data System (ADS)

Frame, Jamie; Rohan, Pierre-Yves; Corté, Laurent; Allena, Rachele

2017-12-01

Successfully simulating tissue evolution in bone is of significant importance in predicting various biological processes such as bone remodeling, fracture healing and osseointegration of implants. Each of these processes involves in different ways the permanent or transient formation of different tissue types, namely bone, cartilage and fibrous tissues. The tissue evolution in specific circumstances such as bone remodeling and fracturing healing is currently able to be modeled. Nevertheless, it remains challenging to predict which tissue types and organization can develop without any a priori assumptions. In particular, the role of mechano-biological coupling in this selective tissue evolution has not been clearly elucidated. In this work, a multi-tissue model has been created which simultaneously describes the evolution of bone, cartilage and fibrous tissues. The coupling of the biological and mechanical factors involved in tissue formation has been modeled by defining two different tissue states: an immature state corresponding to the early stages of tissue growth and representing cell clusters in a weakly neo-formed Extra Cellular Matrix (ECM), and a mature state corresponding to well-formed connective tissues. This has allowed for the cellular processes of migration, proliferation and apoptosis to be described simultaneously with the changing ECM properties through strain driven diffusion, growth, maturation and resorption terms. A series of finite element simulations were carried out on idealized cantilever bending geometries. Starting from a tissue composition replicating a mid-diaphysis section of a long bone, a steady-state tissue formation was reached over a statically loaded period of 10,000 h (60 weeks). The results demonstrated that bone formation occurred in regions which are optimally physiologically strained. In two additional 1000 h bending simulations both cartilaginous and fibrous tissues were shown to form under specific geometrical and loading cases and cartilage was shown to lead to the formation of bone in a beam replicating a fracture healing initial tissue distribution. This finding is encouraging in that it is corroborated by similar experimental observations of cartilage leading bone formation during the fracture healing process. The results of this work demonstrate that a multi-tissue mechano-biological model of tissue evolution has the potential for predictive analysis in the design and implementations of implants, describing fracture healing and bone remodeling processes.

Establishment of primary cell cultures from fish calcified tissues

PubMed Central

Marques, Cátia L.; Rafael, Marta S.; Cancela, M. Leonor

2007-01-01

Fishes have been recently recognized as a suitable model organism to study vertebrate physiological processes, in particular skeletal development and tissue mineralization. However, there is a lack of well characterized in vitro cell systems derived from fish calcified tissues. We describe here a protocol that was successfully used to develop the first calcified tissue-derived cell cultures of fish origin. Vertebra and branchial arches collected from young gilthead seabreams were fragmented then submitted to the combined action of collagenase and trypsin to efficiently release cells embedded in the collagenous extracellular matrix. Primary cultures were maintained under standard conditions and spontaneously transformed to form continuous cell lines suitable for studying mechanisms of tissue mineralization in seabream. This simple and inexpensive protocol is also applicable to other calcified tissues and species by adjusting parameters to each particular case. PMID:19002990

The mechanics of development: models and methods for tissue morphogenesis

PubMed Central

Gjorevski, Nikolce; Nelson, Celeste M.

2011-01-01

Embryonic development is a physical process during which masses of cells are sculpted into functional organs. The mechanical properties of tissues and the forces exerted on them serve as epigenetic regulators of morphogenesis. Understanding these mechanobiological effects in the embryo requires new experimental approaches. Here we focus on branching of the lung airways and bending of the heart tube to describe examples of mechanical and physical cues that guide cell fate decisions and organogenesis. We highlight recent technological advances to measure tissue elasticity and endogenous mechanical stresses in real time during organ development. We also discuss recent progress in manipulating forces in intact embryos. PMID:20860059

Silk Based Bioinks for Soft Tissue Reconstruction Using 3-Dimensional (3D) Printing with in vitro and in vivo Assessments

PubMed Central

Rodriguez, María J.; Brown, Joseph; Giordano, Jodie; Lin, Samuel J.; Omenetto, Fiorenzo G.; Kaplan, David L.

2016-01-01

In the field of soft tissue reconstruction, custom implants could address the need for materials that can fill complex geometries. Our aim was to develop a material system with optimal rheology for material extrusion, that can be processed in physiological and non-toxic conditions and provide structural support for soft tissue reconstruction. To meet this need we developed silk based bioinks using gelatin as a bulking agent and glycerol as a non-toxic additive to induce physical crosslinking. We developed these inks optimizing printing efficacy and resolution for patient-specific geometries that can be used for soft tissue reconstruction. We demonstrated in vitro that the material was stable under physiological conditions and could be tuned to match soft tissue mechanical properties. We demonstrated in vivo that the material was biocompatible and could be tuned to maintain shape and volume up to three months while promoting cellular infiltration and tissue integration. PMID:27940389

Silk based bioinks for soft tissue reconstruction using 3-dimensional (3D) printing with in vitro and in vivo assessments.

PubMed

Rodriguez, María J; Brown, Joseph; Giordano, Jodie; Lin, Samuel J; Omenetto, Fiorenzo G; Kaplan, David L

2017-02-01

In the field of soft tissue reconstruction, custom implants could address the need for materials that can fill complex geometries. Our aim was to develop a material system with optimal rheology for material extrusion, that can be processed in physiological and non-toxic conditions and provide structural support for soft tissue reconstruction. To meet this need we developed silk based bioinks using gelatin as a bulking agent and glycerol as a non-toxic additive to induce physical crosslinking. We developed these inks optimizing printing efficacy and resolution for patient-specific geometries that can be used for soft tissue reconstruction. We demonstrated in vitro that the material was stable under physiological conditions and could be tuned to match soft tissue mechanical properties. We demonstrated in vivo that the material was biocompatible and could be tuned to maintain shape and volume up to three months while promoting cellular infiltration and tissue integration. Copyright © 2016 Elsevier Ltd. All rights reserved.

Roles of Diffusion Dynamics in Stem Cell Signaling and Three-Dimensional Tissue Development.

PubMed

McMurtrey, Richard J

2017-09-15

Recent advancements in the ability to construct three-dimensional (3D) tissues and organoids from stem cells and biomaterials have not only opened abundant new research avenues in disease modeling and regenerative medicine but also have ignited investigation into important aspects of molecular diffusion in 3D cellular architectures. This article describes fundamental mechanics of diffusion with equations for modeling these dynamic processes under a variety of scenarios in 3D cellular tissue constructs. The effects of these diffusion processes and resultant concentration gradients are described in the context of the major molecular signaling pathways in stem cells that both mediate and are influenced by gas and nutrient concentrations, including how diffusion phenomena can affect stem cell state, cell differentiation, and metabolic states of the cell. The application of these diffusion models and pathways is of vital importance for future studies of developmental processes, disease modeling, and tissue regeneration.

Direct-write bioprinting of cell-laden methacrylated gelatin hydrogels.

PubMed

Bertassoni, Luiz E; Cardoso, Juliana C; Manoharan, Vijayan; Cristino, Ana L; Bhise, Nupura S; Araujo, Wesleyan A; Zorlutuna, Pinar; Vrana, Nihal E; Ghaemmaghami, Amir M; Dokmeci, Mehmet R; Khademhosseini, Ali

2014-06-01

Fabrication of three dimensional (3D) organoids with controlled microarchitectures has been shown to enhance tissue functionality. Bioprinting can be used to precisely position cells and cell-laden materials to generate controlled tissue architecture. Therefore, it represents an exciting alternative for organ fabrication. Despite the rapid progress in the field, the development of printing processes that can be used to fabricate macroscale tissue constructs from ECM-derived hydrogels has remained a challenge. Here we report a strategy for bioprinting of photolabile cell-laden methacrylated gelatin (GelMA) hydrogels. We bioprinted cell-laden GelMA at concentrations ranging from 7 to 15% with varying cell densities and found a direct correlation between printability and the hydrogel mechanical properties. Furthermore, encapsulated HepG2 cells preserved cell viability for at least eight days following the bioprinting process. In summary, this work presents a strategy for direct-write bioprinting of a cell-laden photolabile ECM-derived hydrogel, which may find widespread application for tissue engineering, organ printing and the development of 3D drug discovery platforms.

Mathematical modelling of tissue formation in chondrocyte filter cultures.

PubMed

Catt, C J; Schuurman, W; Sengers, B G; van Weeren, P R; Dhert, W J A; Please, C P; Malda, J

2011-12-17

In the field of cartilage tissue engineering, filter cultures are a frequently used three-dimensional differentiation model. However, understanding of the governing processes of in vitro growth and development of tissue in these models is limited. Therefore, this study aimed to further characterise these processes by means of an approach combining both experimental and applied mathematical methods. A mathematical model was constructed, consisting of partial differential equations predicting the distribution of cells and glycosaminoglycans (GAGs), as well as the overall thickness of the tissue. Experimental data was collected to allow comparison with the predictions of the simulation and refinement of the initial models. Healthy mature equine chondrocytes were expanded and subsequently seeded on collagen-coated filters and cultured for up to 7 weeks. Resulting samples were characterised biochemically, as well as histologically. The simulations showed a good representation of the experimentally obtained cell and matrix distribution within the cultures. The mathematical results indicate that the experimental GAG and cell distribution is critically dependent on the rate at which the cell differentiation process takes place, which has important implications for interpreting experimental results. This study demonstrates that large regions of the tissue are inactive in terms of proliferation and growth of the layer. In particular, this would imply that higher seeding densities will not significantly affect the growth rate. A simple mathematical model was developed to predict the observed experimental data and enable interpretation of the principal underlying mechanisms controlling growth-related changes in tissue composition.

Fluid mechanics as a driver of tissue-scale mechanical signaling in organogenesis.

PubMed

Gilbert, Rachel M; Morgan, Joshua T; Marcin, Elizabeth S; Gleghorn, Jason P

2016-12-01

Organogenesis is the process during development by which cells self-assemble into complex, multi-scale tissues. Whereas significant focus and research effort has demonstrated the importance of solid mechanics in organogenesis, less attention has been given to the fluid forces that provide mechanical cues over tissue length scales. Fluid motion and pressure is capable of creating spatial gradients of forces acting on cells, thus eliciting distinct and localized signaling patterns essential for proper organ formation. Understanding the multi-scale nature of the mechanics is critically important to decipher how mechanical signals sculpt developing organs. This review outlines various mechanisms by which tissues generate, regulate, and sense fluid forces and highlights the impact of these forces and mechanisms in case studies of normal and pathological development.

Developmental biology of the pancreas: a comprehensive review.

PubMed

Gittes, George K

2009-02-01

Pancreatic development represents a fascinating process in which two morphologically distinct tissue types must derive from one simple epithelium. These two tissue types, exocrine (including acinar cells, centro-acinar cells, and ducts) and endocrine cells serve disparate functions, and have entirely different morphology. In addition, the endocrine tissue must become disconnected from the epithelial lining during its development. The pancreatic development field has exploded in recent years, and numerous published reviews have dealt specifically with only recent findings, or specifically with certain aspects of pancreatic development. Here I wish to present a more comprehensive review of all aspects of pancreatic development, though still there is not a room for discussion of stem cell differentiation to pancreas, nor for discussion of post-natal regeneration phenomena, two important fields closely related to pancreatic development.

Ultrasonic Shear Wave Elasticity Imaging (SWEI) Sequencing and Data Processing Using a Verasonics Research Scanner

PubMed Central

Deng, Yufeng; Rouze, Ned C.; Palmeri, Mark L.; Nightingale, Kathryn R.

2017-01-01

Ultrasound elasticity imaging has been developed over the last decade to estimate tissue stiffness. Shear wave elasticity imaging (SWEI) quantifies tissue stiffness by measuring the speed of propagating shear waves following acoustic radiation force excitation. This work presents the sequencing and data processing protocols of SWEI using a Verasonics system. The selection of the sequence parameters in a Verasonics programming script is discussed in detail. The data processing pipeline to calculate group shear wave speed (SWS), including tissue motion estimation, data filtering, and SWS estimation is demonstrated. In addition, the procedures for calibration of beam position, scanner timing, and transducer face heating are provided to avoid SWS measurement bias and transducer damage. PMID:28092508

Optimal molecular profiling of tissue and tissue components: defining the best processing and microdissection methods for biomedical applications.

PubMed

Bova, G Steven; Eltoum, Isam A; Kiernan, John A; Siegal, Gene P; Frost, Andra R; Best, Carolyn J M; Gillespie, John W; Su, Gloria H; Emmert-Buck, Michael R

2005-02-01

Isolation of well-preserved pure cell populations is a prerequisite for sound studies of the molecular basis of any tissue-based biological phenomenon. This article reviews current methods for obtaining anatomically specific signals from molecules isolated from tissues, a basic requirement for productive linking of phenotype and genotype. The quality of samples isolated from tissue and used for molecular analysis is often glossed over or omitted from publications, making interpretation and replication of data difficult or impossible. Fortunately, recently developed techniques allow life scientists to better document and control the quality of samples used for a given assay, creating a foundation for improvement in this area. Tissue processing for molecular studies usually involves some or all of the following steps: tissue collection, gross dissection/identification, fixation, processing/embedding, storage/archiving, sectioning, staining, microdissection/annotation, and pure analyte labeling/identification and quantification. We provide a detailed comparison of some current tissue microdissection technologies, and provide detailed example protocols for tissue component handling upstream and downstream from microdissection. We also discuss some of the physical and chemical issues related to optimal tissue processing, and include methods specific to cytology specimens. We encourage each laboratory to use these as a starting point for optimization of their overall process of moving from collected tissue to high quality, appropriately anatomically tagged scientific results. In optimized protocols is a source of inefficiency in current life science research. Improvement in this area will significantly increase life science quality and productivity. The article is divided into introduction, materials, protocols, and notes sections. Because many protocols are covered in each of these sections, information relating to a single protocol is not contiguous. To get the greatest benefit from this article, readers are advised to read through the entire article first, identify protocols appropriate to their laboratory for each step in their workflow, and then reread entries in each section pertaining to each of these single protocols.

Optimal molecular profiling of tissue and tissue components: defining the best processing and microdissection methods for biomedical applications.

PubMed

Rodriguez-Canales, Jaime; Hanson, Jeffrey C; Hipp, Jason D; Balis, Ulysses J; Tangrea, Michael A; Emmert-Buck, Michael R; Bova, G Steven

2013-01-01

Isolation of well-preserved pure cell populations is a prerequisite for sound studies of the molecular basis of any tissue-based biological phenomenon. This updated chapter reviews current methods for obtaining anatomically specific signals from molecules isolated from tissues, a basic requirement for productive linking of phenotype and genotype. The quality of samples isolated from tissue and used for molecular analysis is often glossed over or omitted from publications, making interpretation and replication of data difficult or impossible. Fortunately, recently developed techniques allow life scientists to better document and control the quality of samples used for a given assay, creating a foundation for improvement in this area. Tissue processing for molecular studies usually involves some or all of the following steps: tissue collection, gross dissection/identification, fixation, processing/embedding, storage/archiving, sectioning, staining, microdissection/annotation, and pure analyte labeling/identification and quantification. We provide a detailed comparison of some current tissue microdissection technologies and provide detailed example protocols for tissue component handling upstream and downstream from microdissection. We also discuss some of the physical and chemical issues related to optimal tissue processing and include methods specific to cytology specimens. We encourage each laboratory to use these as a starting point for optimization of their overall process of moving from collected tissue to high-quality, appropriately anatomically tagged scientific results. Improvement in this area will significantly increase life science quality and productivity. The chapter is divided into introduction, materials, protocols, and notes subheadings. Because many protocols are covered in each of these sections, information relating to a single protocol is not contiguous. To get the greatest benefit from this chapter, readers are advised to read through the entire chapter first, identify protocols appropriate to their laboratory for each step in their workflow, and then reread entries in each section pertaining to each of these single protocols.

Development of an Autonomous, Dual Chamber Bioreactor for the Growth of 3-Dimensional Epithelial-Stromal Tissues in Microgravity

NASA Technical Reports Server (NTRS)

Patel, Zarana S.; Wettergreen, Matthew A.; Huff, Janice L.

2014-01-01

We are developing a novel, autonomous bioreactor that can provide for the growth and maintenance in microgravity of 3-D organotypic epithelial-stromal cultures that require an air-liquid interface. These complex 3-D tissue models accurately represent the morphological features, differentiation markers, and growth characteristics observed in normal human epithelial tissues, including the skin, esophagus, lung, breast, pancreas, and colon. However, because of their precise and complex culture requirements, including that of an air-liquid interface, these 3-D models have yet to be utilized for life sciences research aboard the International Space Station. The development of a bioreactor for these cultures will provide the capability to perform biological research on the ISS using these realistic, tissue-like human epithelial-stromal cell models and will contribute significantly to advances in fundamental space biology research on questions regarding microgravity effects on normal tissue development, aging, cancer, and other disease processes. It will also allow for the study of how combined stressors, such as microgravity with radiation and nutritional deficiencies, affect multiple biological processes and will provide a platform for conducting countermeasure investigations on the ISS without the use of animal models. The technology will be autonomous and consist of a cell culture chamber that provides for air-liquid, liquid-liquid, and liquid-air exchanges within the chambers while maintaining the growth and development of the biological samples. The bioreactor will support multiple tissue types and its modular design will provide for incorporation of add-on capabilities such as microfluidics drug delivery, media sampling, and in situ biomarker analysis. Preliminary flight testing of the hardware will be conducted on a parabolic platform through NASA's Flight Opportunities Program.

Optimal molecular profiling of tissue and tissue components: defining the best processing and microdissection methods for biomedical applications.

PubMed

Bova, G Steven; Eltoum, Isam A; Kiernan, John A; Siegal, Gene P; Frost, Andra R; Best, Carolyn J M; Gillespie, John W; Emmert-Buck, Michael R

2005-01-01

Isolation of well-preserved pure cell populations is a prerequisite for sound studies of the molecular basis of pancreatic malignancy and other biological phenomena. This chapter reviews current methods for obtaining anatomically specific signals from molecules isolated from tissues, a basic requirement for productive linking of phenotype and genotype. The quality of samples isolated from tissue and used for molecular analysis is often glossed-over or omitted from publications, making interpretation and replication of data difficult or impossible. Fortunately, recently developed techniques allow life scientists to better document and control the quality of samples used for a given assay, creating a foundation for improvement in this area. Tissue processing for molecular studies usually involves some or all of the following steps: tissue collection, gross dissection/identification, fixation, processing/embedding, storage/archiving, sectioning, staining, microdissection/annotation, and pure analyte labeling/identification. High-quality tissue microdissection does not necessarily mean high-quality samples to analyze. The quality of biomaterials obtained for analysis is highly dependent on steps upstream and downstream from tissue microdissection. We provide protocols for each of these steps, and encourage you to improve upon these. It is worth the effort of every laboratory to optimize and document its technique at each stage of the process, and we provide a starting point for those willing to spend the time to optimize. In our view, poor documentation of tissue and cell type of origin and the use of nonoptimized protocols is a source of inefficiency in current life science research. Even incremental improvement in this area will increase productivity significantly.

High-throughput simultaneous analysis of RNA, protein, and lipid biomarkers in heterogeneous tissue samples.

PubMed

Reiser, Vladimír; Smith, Ryan C; Xue, Jiyan; Kurtz, Marc M; Liu, Rong; Legrand, Cheryl; He, Xuanmin; Yu, Xiang; Wong, Peggy; Hinchcliffe, John S; Tanen, Michael R; Lazar, Gloria; Zieba, Renata; Ichetovkin, Marina; Chen, Zhu; O'Neill, Edward A; Tanaka, Wesley K; Marton, Matthew J; Liao, Jason; Morris, Mark; Hailman, Eric; Tokiwa, George Y; Plump, Andrew S

2011-11-01

With expanding biomarker discovery efforts and increasing costs of drug development, it is critical to maximize the value of mass-limited clinical samples. The main limitation of available methods is the inability to isolate and analyze, from a single sample, molecules requiring incompatible extraction methods. Thus, we developed a novel semiautomated method for tissue processing and tissue milling and division (TMAD). We used a SilverHawk atherectomy catheter to collect atherosclerotic plaques from patients requiring peripheral atherectomy. Tissue preservation by flash freezing was compared with immersion in RNAlater®, and tissue grinding by traditional mortar and pestle was compared with TMAD. Comparators were protein, RNA, and lipid yield and quality. Reproducibility of analyte yield from aliquots of the same tissue sample processed by TMAD was also measured. The quantity and quality of biomarkers extracted from tissue prepared by TMAD was at least as good as that extracted from tissue stored and prepared by traditional means. TMAD enabled parallel analysis of gene expression (quantitative reverse-transcription PCR, microarray), protein composition (ELISA), and lipid content (biochemical assay) from as little as 20 mg of tissue. The mean correlation was r = 0.97 in molecular composition (RNA, protein, or lipid) between aliquots of individual samples generated by TMAD. We also demonstrated that it is feasible to use TMAD in a large-scale clinical study setting. The TMAD methodology described here enables semiautomated, high-throughput sampling of small amounts of heterogeneous tissue specimens by multiple analytical techniques with generally improved quality of recovered biomolecules.

Signaling pathways effecting crosstalk between cartilage and adjacent tissues: Seminars in cell and developmental biology: The biology and pathology of cartilage.

PubMed

Maes, Christa

2017-02-01

Endochondral ossification, the mechanism responsible for the development of the long bones, is dependent on an extremely stringent coordination between the processes of chondrocyte maturation in the growth plate, vascular expansion in the surrounding tissues, and osteoblast differentiation and osteogenesis in the perichondrium and the developing bone center. The synchronization of these processes occurring in adjacent tissues is regulated through vigorous crosstalk between chondrocytes, endothelial cells and osteoblast lineage cells. Our knowledge about the molecular constituents of these bidirectional communications is undoubtedly incomplete, but certainly some signaling pathways effective in cartilage have been recognized to play key roles in steering vascularization and osteogenesis in the perichondrial tissues. These include hypoxia-driven signaling pathways, governed by the hypoxia-inducible factors (HIFs) and vascular endothelial growth factor (VEGF), which are absolutely essential for the survival and functioning of chondrocytes in the avascular growth plate, at least in part by regulating the oxygenation of developing cartilage through the stimulation of angiogenesis in the surrounding tissues. A second coordinating signal emanating from cartilage and regulating developmental processes in the adjacent perichondrium is Indian Hedgehog (IHH). IHH, produced by pre-hypertrophic and early hypertrophic chondrocytes in the growth plate, induces the differentiation of adjacent perichondrial progenitor cells into osteoblasts, thereby harmonizing the site and time of bone formation with the developmental progression of chondrogenesis. Both signaling pathways represent vital mediators of the tightly organized conversion of avascular cartilage into vascularized and mineralized bone during endochondral ossification. Copyright © 2016. Published by Elsevier Ltd.

A kinetic modeling of chondrocyte culture for manufacture of tissue-engineered cartilage.

PubMed

Kino-Oka, Masahiro; Maeda, Yoshikatsu; Yamamoto, Takeyuki; Sugawara, Katsura; Taya, Masahito

2005-03-01

For repairing articular cartilage defects, innovative techniques based on tissue engineering have been developed and are now entering into the practical stage of clinical application by means of grafting in vitro cultured products. A variety of natural and artificial materials available for scaffolds, which permit chondrocyte cells to aggregate, have been designed for their ability to promote cell growth and differentiation. From the viewpoint of the manufacturing process for tissue-engineered cartilage, the diverse nature of raw materials (seeding cells) and end products (cultured cartilage) oblige us to design a tailor-made process with less reproducibility, which is an obstacle to establishing a production doctrine based on bioengineering knowledge concerning growth kinetics and modeling as well as designs of bioreactors and culture operations for certification of high product quality. In this article, we review the recent advances in the manufacturing of tissue-engineered cartilage. After outlining the manufacturing processes for tissue-engineered cartilage in the first section, the second and third sections, respectively, describe the three-dimensional culture of chondrocytes with Aterocollagen gel and kinetic model consideration as a tool for evaluating this culture process. In the final section, culture strategy is discussed in terms of the combined processes of monolayer growth (ex vivo chondrocyte cell expansion) and three-dimensional growth (construction of cultured cartilage in the gel).

Spatiotemporal Evolution of the Wound Repairing Process in a 3D Human Dermis Equivalent.

PubMed

Lombardi, Bernadette; Casale, Costantino; Imparato, Giorgia; Urciuolo, Francesco; Netti, Paolo Antonio

2017-07-01

Several skin equivalent models have been developed to investigate in vitro the re-epithelialization process occurring during wound healing. Although these models recapitulate closure dynamics of epithelial cells, they fail to capture how a wounded connective tissue rebuilds its 3D architecture until the evolution in a scar. Here, the in vitro tissue repair dynamics of a connective tissue is replicated by using a 3D human dermis equivalent (3D-HDE) model composed of fibroblasts embedded in their own extracellular matrix (ECM). After inducing a physical damage, 3D-HDE undergoes a series of cellular and extracellular events quite similar to those occurring in the native dermis. In particular, fibroblasts differentiation toward myofibroblasts phenotype and neosynthesis of hyaluronic acid, fibronectin, and collagen during the repair process are assessed. Moreover, tissue reorganization after physical damage is investigated by measuring the diameter of bundles and the orientation of fibers of the newly formed ECM network. Finally, the ultimate formation of a scar-like tissue as physiological consequence of the repair and closure process is demonstrated. Taking together, the results highlight that the presence of cell-assembled and responsive stromal components enables quantitative and qualitative in vitro evaluation of the processes involved in scarring during wound healing. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Analysis of exhaled breath by laser detection

NASA Astrophysics Data System (ADS)

Thrall, Karla D.; Toth, James J.; Sharpe, Steven W.

1996-04-01

The goal of our work is two fold: (1) to develop a portable rapid laser based breath analyzer for monitoring metabolic processes, and (2) predict these metabolic processes through physiologically based pharmacokinetic (PBPK) modeling. Small infrared active molecules such as ammonia, carbon monoxide, carbon dioxide, methane and ethane are present in exhaled breath and can be readily detected by laser absorption spectroscopy. In addition, many of the stable isotopomers of these molecules can be accurately detected, making it possible to follow specific metabolic processes. Potential areas of applications for this technology include the diagnosis of certain pathologies (e.g. Helicobacter Pylori infection), detection of trauma due to either physical or chemical causes and monitoring nutrient uptake (i.e., malnutrition). In order to understand the origin and elucidate the metabolic processes associated with these small molecules, we are employing physiologically based pharmacokinetic (PBPK) models. A PBPK model is founded on known physiological processes (i.e., blood flow rates, tissue volumes, breathing rate, etc.), chemical-specific processes (i.e., tissue solubility coefficients, molecular weight, chemical density, etc.), and on metabolic processes (tissue site and rate of metabolic biotransformation). Since many of these processes are well understood, a PBPK model can be developed and validated against the more readily available experimental animal data, and then by extrapolating the parameters to apply to man, the model can predict chemical behavior in humans.

A compact and versatile microfluidic probe for local processing of tissue sections and biological specimens

NASA Astrophysics Data System (ADS)

Cors, J. F.; Lovchik, R. D.; Delamarche, E.; Kaigala, G. V.

2014-03-01

The microfluidic probe (MFP) is a non-contact, scanning microfluidic technology for local (bio)chemical processing of surfaces based on hydrodynamically confining nanoliter volumes of liquids over tens of micrometers. We present here a compact MFP (cMFP) that can be used on a standard inverted microscope and assist in the local processing of tissue sections and biological specimens. The cMFP has a footprint of 175 × 100 × 140 mm3 and can scan an area of 45 × 45 mm2 on a surface with an accuracy of ±15 μm. The cMFP is compatible with standard surfaces used in life science laboratories such as microscope slides and Petri dishes. For ease of use, we developed self-aligned mounted MFP heads with standardized "chip-to-world" and "chip-to-platform" interfaces. Switching the processing liquid in the flow confinement is performed within 90 s using a selector valve with a dead-volume of approximately 5 μl. We further implemented height-compensation that allows a cMFP head to follow non-planar surfaces common in tissue and cellular ensembles. This was shown by patterning different macroscopic copper-coated topographies with height differences up to 750 μm. To illustrate the applicability to tissue processing, 5 μm thick M000921 BRAF V600E+ melanoma cell blocks were stained with hematoxylin to create contours, lines, spots, gradients of the chemicals, and multiple spots over larger areas. The local staining was performed in an interactive manner using a joystick and a scripting module. The compactness, user-friendliness, and functionality of the cMFP will enable it to be adapted as a standard tool in research, development and diagnostic laboratories, particularly for the interaction with tissues and cells.

Only in dying, life: programmed cell death during plant development.

PubMed

Van Hautegem, Tom; Waters, Andrew J; Goodrich, Justin; Nowack, Moritz K

2015-02-01

Programmed cell death (PCD) is a fundamental process of life. During the evolution of multicellular organisms, the actively controlled demise of cells has been recruited to fulfil a multitude of functions in development, differentiation, tissue homeostasis, and immune systems. In this review we discuss some of the multiple cases of PCD that occur as integral parts of plant development in a remarkable variety of cell types, tissues, and organs. Although research in the last decade has discovered a number of PCD regulators, mediators, and executers, we are still only beginning to understand the mechanistic complexity that tightly controls preparation, initiation, and execution of PCD as a process that is indispensable for successful vegetative and reproductive development of plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

Printing three-dimensional tissue analogues with decellularized extracellular matrix bioink

PubMed Central

Pati, Falguni; Jang, Jinah; Ha, Dong-Heon; Won Kim, Sung; Rhie, Jong-Won; Shim, Jin-Hyung; Kim, Deok-Ho; Cho, Dong-Woo

2014-01-01

The ability to print and pattern all the components that make up a tissue (cells and matrix materials) in three dimensions to generate structures similar to tissues is an exciting prospect of bioprinting. However, the majority of the matrix materials used so far for bioprinting cannot represent the complexity of natural extracellular matrix (ECM) and thus are unable to reconstitute the intrinsic cellular morphologies and functions. Here, we develop a method for the bioprinting of cell-laden constructs with novel decellularized extracellular matrix (dECM) bioink capable of providing an optimized microenvironment conducive to the growth of three-dimensional structured tissue. We show the versatility and flexibility of the developed bioprinting process using tissue-specific dECM bioinks, including adipose, cartilage and heart tissues, capable of providing crucial cues for cells engraftment, survival and long-term function. We achieve high cell viability and functionality of the printed dECM structures using our bioprinting method. PMID:24887553

Micromechanical Modeling Study of Mechanical Inhibition of Enzymatic Degradation of Collagen Tissues

PubMed Central

Tonge, Theresa K.; Ruberti, Jeffrey W.; Nguyen, Thao D.

2015-01-01

This study investigates how the collagen fiber structure influences the enzymatic degradation of collagen tissues. We developed a micromechanical model of a fibrous collagen tissue undergoing enzymatic degradation based on two central hypotheses. The collagen fibers are crimped in the undeformed configuration. Enzymatic degradation is an energy activated process and the activation energy is increased by the axial strain energy density of the fiber. We determined the intrinsic degradation rate and characteristic energy for mechanical inhibition from fibril-level degradation experiments and applied the parameters to predict the effect of the crimped fiber structure and fiber properties on the degradation of bovine cornea and pericardium tissues under controlled tension. We then applied the model to examine the effect of the tissue stress state on the rate of tissue degradation and the anisotropic fiber structures that developed from enzymatic degradation. PMID:26682825

Printing three-dimensional tissue analogues with decellularized extracellular matrix bioink

NASA Astrophysics Data System (ADS)

Pati, Falguni; Jang, Jinah; Ha, Dong-Heon; Won Kim, Sung; Rhie, Jong-Won; Shim, Jin-Hyung; Kim, Deok-Ho; Cho, Dong-Woo

2014-06-01

The ability to print and pattern all the components that make up a tissue (cells and matrix materials) in three dimensions to generate structures similar to tissues is an exciting prospect of bioprinting. However, the majority of the matrix materials used so far for bioprinting cannot represent the complexity of natural extracellular matrix (ECM) and thus are unable to reconstitute the intrinsic cellular morphologies and functions. Here, we develop a method for the bioprinting of cell-laden constructs with novel decellularized extracellular matrix (dECM) bioink capable of providing an optimized microenvironment conducive to the growth of three-dimensional structured tissue. We show the versatility and flexibility of the developed bioprinting process using tissue-specific dECM bioinks, including adipose, cartilage and heart tissues, capable of providing crucial cues for cells engraftment, survival and long-term function. We achieve high cell viability and functionality of the printed dECM structures using our bioprinting method.

Method for Producing Non-Neoplastic, Three Dimensional, Mammalian Tissue and Cell Aggregates Under Microgravity Culture Conditions and the Products Produced Therefrom

NASA Technical Reports Server (NTRS)

Goodwin, Thomas J. (Inventor); Wolf, David A. (Inventor); Spaulding, Glenn F. (Inventor); Prewett, Tracey L. (Inventor)

1996-01-01

Normal mammalian tissue and the culturing process has been developed for the three groups of organ, structural, and blood tissue. The cells are grown in vitro under microgravity culture conditions and form three dimensional cells aggregates with normal cell function. The microgravity culture conditions may be microgravity or simulated microgravity created in a horizontal rotating wall culture vessel.

Considerations in establishing a post-mortem brain and tissue bank for the study of myalgic encephalomyelitis/chronic fatigue syndrome: a proposed protocol

PubMed Central

2014-01-01

Background Our aim, having previously investigated through a qualitative study involving extensive discussions with experts and patients the issues involved in establishing and maintaining a disease specific brain and tissue bank for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), was to develop a protocol for a UK ME/CFS repository of high quality human tissue from well characterised subjects with ME/CFS and controls suitable for a broad range of research applications. This would involve a specific donor program coupled with rapid tissue collection and processing, supplemented by comprehensive prospectively collected clinical, laboratory and self-assessment data from cases and controls. Findings We reviewed the operations of existing tissue banks from published literature and from their internal protocols and standard operating procedures (SOPs). On this basis, we developed the protocol presented here, which was designed to meet high technical and ethical standards and legal requirements and was based on recommendations of the MRC UK Brain Banks Network. The facility would be most efficient and cost-effective if incorporated into an existing tissue bank. Tissue collection would be rapid and follow robust protocols to ensure preservation sufficient for a wide range of research uses. A central tissue bank would have resources both for wide-scale donor recruitment and rapid response to donor death for prompt harvesting and processing of tissue. Conclusion An ME/CFS brain and tissue bank could be established using this protocol. Success would depend on careful consideration of logistic, technical, legal and ethical issues, continuous consultation with patients and the donor population, and a sustainable model of funding ideally involving research councils, health services, and patient charities. This initiative could revolutionise the understanding of this still poorly-understood disease and enhance development of diagnostic biomarkers and treatments. PMID:24938650

Lung Regeneration: Endogenous and Exogenous Stem Cell Mediated Therapeutic Approaches.

PubMed

Akram, Khondoker M; Patel, Neil; Spiteri, Monica A; Forsyth, Nicholas R

2016-01-19

The tissue turnover of unperturbed adult lung is remarkably slow. However, after injury or insult, a specialised group of facultative lung progenitors become activated to replenish damaged tissue through a reparative process called regeneration. Disruption in this process results in healing by fibrosis causing aberrant lung remodelling and organ dysfunction. Post-insult failure of regeneration leads to various incurable lung diseases including chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis. Therefore, identification of true endogenous lung progenitors/stem cells, and their regenerative pathway are crucial for next-generation therapeutic development. Recent studies provide exciting and novel insights into postnatal lung development and post-injury lung regeneration by native lung progenitors. Furthermore, exogenous application of bone marrow stem cells, embryonic stem cells and inducible pluripotent stem cells (iPSC) show evidences of their regenerative capacity in the repair of injured and diseased lungs. With the advent of modern tissue engineering techniques, whole lung regeneration in the lab using de-cellularised tissue scaffold and stem cells is now becoming reality. In this review, we will highlight the advancement of our understanding in lung regeneration and development of stem cell mediated therapeutic strategies in combating incurable lung diseases.

Sensory processing of deep tissue nociception in the rat spinal cord and thalamic ventrobasal complex.

PubMed

Sikandar, Shafaq; West, Steven J; McMahon, Stephen B; Bennett, David L; Dickenson, Anthony H

2017-07-01

Sensory processing of deep somatic tissue constitutes an important component of the nociceptive system, yet associated central processing pathways remain poorly understood. Here, we provide a novel electrophysiological characterization and immunohistochemical analysis of neural activation in the lateral spinal nucleus (LSN). These neurons show evoked activity to deep, but not cutaneous, stimulation. The evoked responses of neurons in the LSN can be sensitized to somatosensory stimulation following intramuscular hypertonic saline, an acute model of muscle pain, suggesting this is an important spinal relay site for the processing of deep tissue nociceptive inputs. Neurons of the thalamic ventrobasal complex (VBC) mediate both cutaneous and deep tissue sensory processing, but in contrast to the lateral spinal nucleus our electrophysiological studies do not suggest the existence of a subgroup of cells that selectively process deep tissue inputs. The sensitization of polymodal and thermospecific VBC neurons to mechanical somatosensory stimulation following acute muscle stimulation with hypertonic saline suggests differential roles of thalamic subpopulations in mediating cutaneous and deep tissue nociception in pathological states. Overall, our studies at both the spinal (lateral spinal nucleus) and supraspinal (thalamic ventrobasal complex) levels suggest a convergence of cutaneous and deep somatosensory inputs onto spinothalamic pathways, which are unmasked by activation of muscle nociceptive afferents to produce consequent phenotypic alterations in spinal and thalamic neural coding of somatosensory stimulation. A better understanding of the sensory pathways involved in deep tissue nociception, as well as the degree of labeled line and convergent pathways for cutaneous and deep somatosensory inputs, is fundamental to developing targeted analgesic therapies for deep pain syndromes. © 2017 University College London. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

Cell biology and biotechnology research for exploration of the Moon and Mars

NASA Astrophysics Data System (ADS)

Pellis, N.; North, R.

Health risks generated by human long exposure to radiation, microgravity, and unknown factors in the planetary environment are the major unresolved issues for human space exploration. A complete characterization of human and other biological systems adaptation processes to long-duration space missions is necessary for the development of countermeasures. The utilization of cell and engineered tissue cultures in space research and exploration complements research in human, animal, and plant subjects. We can bring a small number of humans, animals, or plants to the ISS, Moon, and Mars. However, we can investigate millions of their cells during these missions. Furthermore, many experiments can not be performed on humans, e.g. radiation exposure, cardiac muscle. Cells from critical tissues and tissue constructs per se are excellent subjects for experiments that address underlying mechanisms important to countermeasures. The development of cell tissue engineered for replacement, implantation of biomaterial to induce tissue regeneration (e.g. absorbable collagen matrix for guiding tissue regeneration in periodontal surgery), and immunoisolation (e.g. biopolymer coating on transplanted tissues to ward off immunological rejection) are good examples of cell research and biotechnology applications. NASA Cell Biology and Biotechnology research include Bone/Muscle and Cardiovascular cell culture and tissue engineering; Environmental Health and Life Support Systems; Immune System; Radiation; Gravity Thresholds ; and Advanced Biotechnology Development to increase the understanding of animal and plant cell adaptive behavior when exposed to space, and to advance technologies that facilitates exploration. Cell systems can be used to investigate processes related to food, microbial proliferation, waste management, biofilms and biomaterials. The NASA Cell Science Program has the advantage of conducting research in microgravity based on significantly small resources, and the ability to conduct experiments in the early phase of the development of requirements for exploration. Supporting the NASA concept of stepping stones, we believe that ground based, International Space Station, robotic and satellite missions offer the ideal environment to perform experiments and secure answers necessary for human exploration.

Tissue specific characterisation of Lim-kinase 1 expression during mouse embryogenesis

PubMed Central

Lindström, Nils O.; Neves, Carlos; McIntosh, Rebecca; Miedzybrodzka, Zosia; Vargesson, Neil; Collinson, J. Martin

2012-01-01

The Lim-kinase (LIMK) proteins are important for the regulation of the actin cytoskeleton, in particular the control of actin nucleation and depolymerisation via regulation of cofilin, and hence may control a large number of processes during development, including cell tensegrity, migration, cell cycling, and axon guidance. LIMK1/LIMK2 knockouts disrupt spinal cord morphogenesis and synapse formation but other tissues and developmental processes that require LIMK are yet to be fully determined. To identify tissues and cell-types that may require LIMK, we characterised the pattern of LIMK1 protein during mouse embryogenesis. We showed that LIMK1 displays an expression pattern that is temporally dynamic and tissue-specific. In several tissues LIMK1 is detected in cell-types that also express Wilms’ tumour protein 1 and that undergo transitions between epithelial and mesenchymal states, including the pleura, epicardium, kidney nephrons, and gonads. LIMK1 was also found in a subset of cells in the dorsal retina, and in mesenchymal cells surrounding the peripheral nerves. This detailed study of the spatial and temporal expression of LIMK1 shows that LIMK1 expression is more dynamic than previously reported, in particular at sites of tissue–tissue interactions guiding multiple developmental processes. PMID:21167960

The model of drugs distribution dynamics in biological tissue

NASA Astrophysics Data System (ADS)

Ginevskij, D. A.; Izhevskij, P. V.; Sheino, I. N.

2017-09-01

The dose distribution by Neutron Capture Therapy follows the distribution of 10B in the tissue. The modern models of pharmacokinetics of drugs describe the processes occurring in conditioned "chambers" (blood-organ-tumor), but fail to describe the spatial distribution of the drug in the tumor and in normal tissue. The mathematical model of the spatial distribution dynamics of drugs in the tissue, depending on the concentration of the drug in the blood, was developed. The modeling method is the representation of the biological structure in the form of a randomly inhomogeneous medium in which the 10B distribution occurs. The parameters of the model, which cannot be determined rigorously in the experiment, are taken as the quantities subject to the laws of the unconnected random processes. The estimates of 10B distribution preparations in the tumor and healthy tissue, inside/outside the cells, are obtained.

A large parosteal ossifying lipoma of lower limb encircling the femur

PubMed Central

2014-01-01

Introduction Lipoma is a benign soft tissue neoplasm that may contain mesenchymal elements, as a result of metaplastic process. Ossification in benign and malignant soft tissue tumors can also manifest due to metaplastic process. Case presentation A 45 year old woman presented with a large thigh mass. The mass was developed one and a half year ago which insidiously increased in size and was associated with movement restriction. Radiological findings revealed soft tissue neoplasm on antero-medial aspect of thigh encircling the femur and displacing adjacent muscles. Fine trabeculations were seen in neoplasm suggestive of ossification. Excision of the mass was performed and histopathology revealed adipocytes with mature bony trabeculae possessing prominent osteoblastic rimming suggestive of ossifying lipoma. Conclusion It is important to recognize this variant of lipoma as it is associated with a better clinical outcome in contrast to most of the deep seated soft tissue neoplasms. Secondly it should also be differentiated from myositis ossificans and heterologous differentiation in other soft tissue neoplasms. We suggest an algorithmic approach to the diagnosis of ossifying soft tissue neoplasms histopathologically. Mature bony trabeculae with prominent osteoblastic rimming in a soft tissue lesion are due to a metaplastic process and should not be confused with osteosarcoma. PMID:24433545

Fluid mechanics as a driver of tissue-scale mechanical signaling in organogenesis

PubMed Central

Gilbert, Rachel M.; Morgan, Joshua T.; Marcin, Elizabeth S.; Gleghorn, Jason P.

2016-01-01

Purpose of Review Organogenesis is the process during development by which cells self-assemble into complex, multi-scale tissues. Whereas significant focus and research effort has demonstrated the importance of solid mechanics in organogenesis, less attention has been given to the fluid forces that provide mechanical cues over tissue length scales. Recent Findings Fluid motion and pressure is capable of creating spatial gradients of forces acting on cells, thus eliciting distinct and localized signaling patterns essential for proper organ formation. Understanding the multi-scale nature of the mechanics is critically important to decipher how mechanical signals sculpt developing organs. Summary This review outlines various mechanisms by which tissues generate, regulate, and sense fluid forces and highlights the impact of these forces and mechanisms in case studies of normal and pathological development. PMID:28163984

Tissue architecture and breast cancer: the role of extracellular matrix and steroid hormones

PubMed Central

Hansen, R K; Bissell, M J

2010-01-01

The changes in tissue architecture that accompany the development of breast cancer have been the focus of investigations aimed at developing new cancer therapeutics. As we learn more about the normal mammary gland, we have begun to understand the complex signaling pathways underlying the dramatic shifts in the structure and function of breast tissue. Integrin-, growth factor-, and steroid hormone-signaling pathways all play an important part in maintaining tissue architecture; disruption of the delicate balance of signaling results in dramatic changes in the way cells interact with each other and with the extracellular matrix, leading to breast cancer. The extracellular matrix itself plays a central role in coordinating these signaling processes. In this review, we consider the interrelationships between the extracellular matrix, integrins, growth factors, and steroid hormones in mammary gland development and function. PMID:10903527

Practical protocols for fast histopathology by Fourier transform infrared spectroscopic imaging

NASA Astrophysics Data System (ADS)

Keith, Frances N.; Reddy, Rohith K.; Bhargava, Rohit

2008-02-01

Fourier transform infrared (FT-IR) spectroscopic imaging is an emerging technique that combines the molecular selectivity of spectroscopy with the spatial specificity of optical microscopy. We demonstrate a new concept in obtaining high fidelity data using commercial array detectors coupled to a microscope and Michelson interferometer. Next, we apply the developed technique to rapidly provide automated histopathologic information for breast cancer. Traditionally, disease diagnoses are based on optical examinations of stained tissue and involve a skilled recognition of morphological patterns of specific cell types (histopathology). Consequently, histopathologic determinations are a time consuming, subjective process with innate intra- and inter-operator variability. Utilizing endogenous molecular contrast inherent in vibrational spectra, specially designed tissue microarrays and pattern recognition of specific biochemical features, we report an integrated algorithm for automated classifications. The developed protocol is objective, statistically significant and, being compatible with current tissue processing procedures, holds potential for routine clinical diagnoses. We first demonstrate that the classification of tissue type (histology) can be accomplished in a manner that is robust and rigorous. Since data quality and classifier performance are linked, we quantify the relationship through our analysis model. Last, we demonstrate the application of the minimum noise fraction (MNF) transform to improve tissue segmentation.

Gradient biomaterials and their influences on cell migration

PubMed Central

Wu, Jindan; Mao, Zhengwei; Tan, Huaping; Han, Lulu; Ren, Tanchen; Gao, Changyou

2012-01-01

Cell migration participates in a variety of physiological and pathological processes such as embryonic development, cancer metastasis, blood vessel formation and remoulding, tissue regeneration, immune surveillance and inflammation. The cells specifically migrate to destiny sites induced by the gradually varying concentration (gradient) of soluble signal factors and the ligands bound with the extracellular matrix in the body during a wound healing process. Therefore, regulation of the cell migration behaviours is of paramount importance in regenerative medicine. One important way is to create a microenvironment that mimics the in vivo cellular and tissue complexity by incorporating physical, chemical and biological signal gradients into engineered biomaterials. In this review, the gradients existing in vivo and their influences on cell migration are briefly described. Recent developments in the fabrication of gradient biomaterials for controlling cellular behaviours, especially the cell migration, are summarized, highlighting the importance of the intrinsic driving mechanism for tissue regeneration and the design principle of complicated and advanced tissue regenerative materials. The potential uses of the gradient biomaterials in regenerative medicine are introduced. The current and future trends in gradient biomaterials and programmed cell migration in terms of the long-term goals of tissue regeneration are prospected. PMID:23741610

3D printing facilitated scaffold-free tissue unit fabrication.

PubMed

Tan, Yu; Richards, Dylan J; Trusk, Thomas C; Visconti, Richard P; Yost, Michael J; Kindy, Mark S; Drake, Christopher J; Argraves, William Scott; Markwald, Roger R; Mei, Ying

2014-06-01

Tissue spheroids hold great potential in tissue engineering as building blocks to assemble into functional tissues. To date, agarose molds have been extensively used to facilitate fusion process of tissue spheroids. As a molding material, agarose typically requires low temperature plates for gelation and/or heated dispenser units. Here, we proposed and developed an alginate-based, direct 3D mold-printing technology: 3D printing microdroplets of alginate solution into biocompatible, bio-inert alginate hydrogel molds for the fabrication of scaffold-free tissue engineering constructs. Specifically, we developed a 3D printing technology to deposit microdroplets of alginate solution on calcium containing substrates in a layer-by-layer fashion to prepare ring-shaped 3D hydrogel molds. Tissue spheroids composed of 50% endothelial cells and 50% smooth muscle cells were robotically placed into the 3D printed alginate molds using a 3D printer, and were found to rapidly fuse into toroid-shaped tissue units. Histological and immunofluorescence analysis indicated that the cells secreted collagen type I playing a critical role in promoting cell-cell adhesion, tissue formation and maturation.

Biological wound dressings sterilized with gamma radiation: Mexican clinical experience

NASA Astrophysics Data System (ADS)

Martínez-Pardo, M. E.; Ley-Chávez, E.; Reyes-Frías, M. L.; Rodríguez-Ferreyra, P.; Vázquez-Maya, L.; Salazar, M. A.

2007-11-01

Biological wound dressings sterilized with gamma radiation, such as amnion and pig skin, are a reality in Mexico. These tissues are currently processed in the tissue bank and sterilized in the Gamma Industrial Irradiation Plant; both facilities belong to the Instituto Nacional de Investigaciones Nucleares (ININ) (National Institute of Nuclear Research). With the strong support of the International Atomic Energy Agency, the bank was established at the ININ and the Mexican Ministry of Health issued its sanitary license on July 7, 1999. The Quality Management System of the bank was certified by ISO 9001:2000 on August 1, 2003; the scope of the system is "Research, Development and Processing of Biological Tissues Sterilized with Gamma Radiation". At present, more than 150 patients from 16 hospitals have been successfully treated with these tissues. This paper presents a brief description of the tissue processing, as well as the present Mexican clinical experience with children and adult patients who underwent medical treatment with radiosterilized amnion and pig skin, used as biological wound dressings on burns and ocular surface disorders.

Multimodal optical imaging database from tumour brain human tissue: endogenous fluorescence from glioma, metastasis and control tissues

NASA Astrophysics Data System (ADS)

Poulon, Fanny; Ibrahim, Ali; Zanello, Marc; Pallud, Johan; Varlet, Pascale; Malouki, Fatima; Abi Lahoud, Georges; Devaux, Bertrand; Abi Haidar, Darine

2017-02-01

Eliminating time-consuming process of conventional biopsy is a practical improvement, as well as increasing the accuracy of tissue diagnoses and patient comfort. We addressed these needs by developing a multimodal nonlinear endomicroscope that allows real-time optical biopsies during surgical procedure. It will provide immediate information for diagnostic use without removal of tissue and will assist the choice of the optimal surgical strategy. This instrument will combine several means of contrast: non-linear fluorescence, second harmonic generation signal, reflectance, fluorescence lifetime and spectral analysis. Multimodality is crucial for reliable and comprehensive analysis of tissue. Parallel to the instrumental development, we currently improve our understanding of the endogeneous fluorescence signal with the different modalities that will be implemented in the stated. This endeavor will allow to create a database on the optical signature of the diseased and control brain tissues. This proceeding will present the preliminary results of this database on three types of tissues: cortex, metastasis and glioblastoma.

ECM-Based Materials in Cardiovascular Applications: Inherent Healing Potential and Augmentation of Native Regenerative Processes

PubMed Central

Piterina, Anna V.; Cloonan, Aidan J.; Meaney, Claire L.; Davis, Laura M.; Callanan, Anthony; Walsh, Michael T.; McGloughlin, Tim M.

2009-01-01

The in vivo healing process of vascular grafts involves the interaction of many contributing factors. The ability of vascular grafts to provide an environment which allows successful accomplishment of this process is extremely difficult. Poor endothelisation, inflammation, infection, occlusion, thrombosis, hyperplasia and pseudoaneurysms are common issues with synthetic grafts in vivo. Advanced materials composed of decellularised extracellular matrices (ECM) have been shown to promote the healing process via modulation of the host immune response, resistance to bacterial infections, allowing re-innervation and reestablishing homeostasis in the healing region. The physiological balance within the newly developed vascular tissue is maintained via the recreation of correct biorheology and mechanotransduction factors including host immune response, infection control, homing and the attraction of progenitor cells and infiltration by host tissue. Here, we review the progress in this tissue engineering approach, the enhancement potential of ECM materials and future prospects to reach the clinical environment. PMID:20057951

Systematic gene microarray analysis of the lncRNA expression profiles in human uterine cervix carcinoma.

PubMed

Chen, Jie; Fu, Ziyi; Ji, Chenbo; Gu, Pingqing; Xu, Pengfei; Yu, Ningzhu; Kan, Yansheng; Wu, Xiaowei; Shen, Rong; Shen, Yan

2015-05-01

The human uterine cervix carcinoma is one of the most well-known malignancy reproductive system cancers, which threatens women health globally. However, the mechanisms of the oncogenesis and development process of cervix carcinoma are not yet fully understood. Long non-coding RNAs (lncRNAs) have been proved to play key roles in various biological processes, especially development of cancer. The function and mechanism of lncRNAs on cervix carcinoma is still rarely reported. We selected 3 cervix cancer and normal cervix tissues separately, then performed lncRNA microarray to detect the differentially expressed lncRNAs. Subsequently, we explored the potential function of these dysregulated lncRNAs through online bioinformatics databases. Finally, quantity real-time PCR was carried out to confirm the expression levels of these dysregulated lncRNAs in cervix cancer and normal tissues. We uncovered the profiles of differentially expressed lncRNAs between normal and cervix carcinoma tissues by using the microarray techniques, and found 1622 upregulated and 3026 downregulated lncRNAs (fold-change>2.0) in cervix carcinoma compared to the normal cervical tissue. Furthermore, we found HOXA11-AS might participate in cervix carcinogenesis by regulating HOXA11, which is involved in regulating biological processes of cervix cancer. This study afforded expression profiles of lncRNAs between cervix carcinoma tissue and normal cervical tissue, which could provide database for further research about the function and mechanism of key-lncRNAs in cervix carcinoma, and might be helpful to explore potential diagnosis factors and therapeutic targets for cervix carcinoma. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Development of an Indirect Stereolithography Technology for Scaffold Fabrication with a Wide Range of Biomaterial Selectivity

PubMed Central

Kang, Hyun-Wook

2012-01-01

Tissue engineering, which is the study of generating biological substitutes to restore or replace tissues or organs, has the potential to meet current needs for organ transplantation and medical interventions. Various approaches have been attempted to apply three-dimensional (3D) solid freeform fabrication technologies to tissue engineering for scaffold fabrication. Among these, the stereolithography (SL) technology not only has the highest resolution, but also offers quick fabrication. However, a lack of suitable biomaterials is a barrier to applying the SL technology to tissue engineering. In this study, an indirect SL method that combines the SL technology and a sacrificial molding process was developed to address this challenge. A sacrificial mold with an inverse porous shape was fabricated from an alkali-soluble photopolymer by the SL technology. A sacrificial molding process was then developed for scaffold construction using a variety of biomaterials. The results indicated a wide range of biomaterial selectivity and a high resolution. Achievable minimum pore and strut sizes were as large as 50 and 65 μm, respectively. This technology can also be used to fabricate three-dimensional organ shapes, and combined with traditional fabrication methods to construct a new type of scaffold with a dual-pore size. Cytotoxicity tests, as well as nuclear magnetic resonance and gel permeation chromatography analyses, showed that this technology has great potential for tissue engineering applications. PMID:22443315

Review: role of carbon sources for in vitro plant growth and development.

PubMed

Yaseen, Mehwish; Ahmad, Touqeer; Sablok, Gaurav; Standardi, Alvaro; Hafiz, Ishfaq Ahmad

2013-04-01

In vitro plant cells, tissues and organ cultures are not fully autotrophic establishing a need for carbohydrates in culture media to maintain the osmotic potential, as well as to serve as energy and carbon sources for developmental processes including shoot proliferation, root induction as well as emission, embryogenesis and organogenesis, which are highly energy demanding developmental processes in plant biology. A variety of carbon sources (both reducing and non-reducing) are used in culture media depending upon genotypes and specific stages of growth. However, sucrose is most widely used as a major transport-sugar in the phloem sap of many plants. In micropropagation systems, morphogenetic potential of plant tissues can greatly be manipulated by varying type and concentration of carbon sources. The present article reviews the past and current findings on carbon sources and their sustainable utilization for in vitro plant tissue culture to achieve better growth rate and development.

Robust tissue classification for reproducible wound assessment in telemedicine environments

NASA Astrophysics Data System (ADS)

Wannous, Hazem; Treuillet, Sylvie; Lucas, Yves

2010-04-01

In telemedicine environments, a standardized and reproducible assessment of wounds, using a simple free-handled digital camera, is an essential requirement. However, to ensure robust tissue classification, particular attention must be paid to the complete design of the color processing chain. We introduce the key steps including color correction, merging of expert labeling, and segmentation-driven classification based on support vector machines. The tool thus developed ensures stability under lighting condition, viewpoint, and camera changes, to achieve accurate and robust classification of skin tissues. Clinical tests demonstrate that such an advanced tool, which forms part of a complete 3-D and color wound assessment system, significantly improves the monitoring of the healing process. It achieves an overlap score of 79.3 against 69.1% for a single expert, after mapping on the medical reference developed from the image labeling by a college of experts.

Development of an Automated Modality-Independent Elastographic Image Analysis System for Tumor Screening

DTIC Science & Technology

2006-02-01

further develop modality-independent elastography as a system that is able to reproducibly detect regions of increased stiffness within the breast based...tested on a tissue-like polymer phantom. elastography , breast cancer screening, image processing 16. SECURITY CLASSIFICATION OF: 17. LIMITATION...is a map of the breast (or other tissue of interest) that reflects material inhomogeneity, such as in the case of a tumor mass that disrupts the

Plasma and cellular fibronectin: distinct and independent functions during tissue repair

PubMed Central

2011-01-01

Fibronectin (FN) is a ubiquitous extracellular matrix (ECM) glycoprotein that plays vital roles during tissue repair. The plasma form of FN circulates in the blood, and upon tissue injury, is incorporated into fibrin clots to exert effects on platelet function and to mediate hemostasis. Cellular FN is then synthesized and assembled by cells as they migrate into the clot to reconstitute damaged tissue. The assembly of FN into a complex three-dimensional matrix during physiological repair plays a key role not only as a structural scaffold, but also as a regulator of cell function during this stage of tissue repair. FN fibrillogenesis is a complex, stepwise process that is strictly regulated by a multitude of factors. During fibrosis, there is excessive deposition of ECM, of which FN is one of the major components. Aberrant FN-matrix assembly is a major contributing factor to the switch from normal tissue repair to misregulated fibrosis. Understanding the mechanisms involved in FN assembly and how these interplay with cellular, fibrotic and immune responses may reveal targets for the future development of therapies to regulate aberrant tissue-repair processes. PMID:21923916

Integration of lncRNA and mRNA Transcriptome Analyses Reveals Genes and Pathways Potentially Involved in Calf Intestinal Growth and Development during the Early Weeks of Life

PubMed Central

Do, Duy N.; Dudemaine, Pier-Luc; Fomenky, Bridget E.

2018-01-01

A better understanding of the factors that regulate growth and immune response of the gastrointestinal tract (GIT) of calves will promote informed management practices in calf rearing. This study aimed to explore genomics (messenger RNA (mRNA)) and epigenomics (long non-coding RNA (lncRNA)) mechanisms regulating the development of the rumen and ileum in calves. Thirty-two calves (≈5-days-old) were reared for 96 days following standard procedures. Sixteen calves were humanely euthanized on experiment day 33 (D33) (pre-weaning) and another 16 on D96 (post-weaning) for collection of ileum and rumen tissues. RNA from tissues was subjected to next generation sequencing and 3310 and 4217 mRNAs were differentially expressed (DE) between D33 and D96 in ileum and rumen tissues, respectively. Gene ontology and pathways enrichment of DE genes confirmed their roles in developmental processes, immunity and lipid metabolism. A total of 1568 (63 known and 1505 novel) and 4243 (88 known and 4155 novel) lncRNAs were detected in ileum and rumen tissues, respectively. Cis target gene analysis identified BMPR1A, an important gene for a GIT disease (juvenile polyposis syndrome) in humans, as a candidate cis target gene for lncRNAs in both tissues. LncRNA cis target gene enrichment suggested that lncRNAs might regulate growth and development in both tissues as well as posttranscriptional gene silencing by RNA or microRNA processing in rumen, or disease resistance mechanisms in ileum. This study provides a catalog of bovine lncRNAs and set a baseline for exploring their functions in calf GIT development. PMID:29510583

Integration of lncRNA and mRNA Transcriptome Analyses Reveals Genes and Pathways Potentially Involved in Calf Intestinal Growth and Development during the Early Weeks of Life.

PubMed

Ibeagha-Awemu, Eveline M; Do, Duy N; Dudemaine, Pier-Luc; Fomenky, Bridget E; Bissonnette, Nathalie

2018-03-05

A better understanding of the factors that regulate growth and immune response of the gastrointestinal tract (GIT) of calves will promote informed management practices in calf rearing. This study aimed to explore genomics (messenger RNA (mRNA)) and epigenomics (long non-coding RNA (lncRNA)) mechanisms regulating the development of the rumen and ileum in calves. Thirty-two calves (≈5-days-old) were reared for 96 days following standard procedures. Sixteen calves were humanely euthanized on experiment day 33 (D33) (pre-weaning) and another 16 on D96 (post-weaning) for collection of ileum and rumen tissues. RNA from tissues was subjected to next generation sequencing and 3310 and 4217 mRNAs were differentially expressed (DE) between D33 and D96 in ileum and rumen tissues, respectively. Gene ontology and pathways enrichment of DE genes confirmed their roles in developmental processes, immunity and lipid metabolism. A total of 1568 (63 known and 1505 novel) and 4243 (88 known and 4155 novel) lncRNAs were detected in ileum and rumen tissues, respectively. Cis target gene analysis identified BMPR1A , an important gene for a GIT disease (juvenile polyposis syndrome) in humans, as a candidate cis target gene for lncRNAs in both tissues. LncRNA cis target gene enrichment suggested that lncRNAs might regulate growth and development in both tissues as well as posttranscriptional gene silencing by RNA or microRNA processing in rumen, or disease resistance mechanisms in ileum. This study provides a catalog of bovine lncRNAs and set a baseline for exploring their functions in calf GIT development.

Multi-scale mechanics from molecules to morphogenesis

PubMed Central

Davidson, Lance; von Dassow, Michelangelo; Zhou, Jian

2009-01-01

Dynamic mechanical processes shape the embryo and organs during development. Little is understood about the basic physics of these processes, what forces are generated, or how tissues resist or guide those forces during morphogenesis. This review offers an outline of some of the basic principles of biomechanics, provides working examples of biomechanical analyses of developing embryos, and reviews the role of structural proteins in establishing and maintaining the mechanical properties of embryonic tissues. Drawing on examples we highlight the importance of investigating mechanics at multiple scales from milliseconds to hours and from individual molecules to whole embryos. Lastly, we pose a series of questions that will need to be addressed if we are to understand the larger integration of molecular and physical mechanical processes during morphogenesis and organogenesis. PMID:19394436

Cartilage tissue engineering: From biomaterials and stem cells to osteoarthritis treatments.

PubMed

Vinatier, C; Guicheux, J

2016-06-01

Articular cartilage is a non-vascularized and poorly cellularized connective tissue that is frequently damaged as a result of trauma and degenerative joint diseases such as osteoarthrtis. Because of the absence of vascularization, articular cartilage has low capacity for spontaneous repair. Today, and despite a large number of preclinical data, no therapy capable of restoring the healthy structure and function of damaged articular cartilage is clinically available. Tissue-engineering strategies involving the combination of cells, scaffolding biomaterials and bioactive agents have been of interest notably for the repair of damaged articular cartilage. During the last 30 years, cartilage tissue engineering has evolved from the treatment of focal lesions of articular cartilage to the development of strategies targeting the osteoarthritis process. In this review, we focus on the different aspects of tissue engineering applied to cartilage engineering. We first discuss cells, biomaterials and biological or environmental factors instrumental to the development of cartilage tissue engineering, then review the potential development of cartilage engineering strategies targeting new emerging pathogenic mechanisms of osteoarthritis. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

The role of adipose tissue in cancer-associated cachexia.

PubMed

Vaitkus, Janina A; Celi, Francesco S

2017-03-01

Adipose tissue (fat) is a heterogeneous organ, both in function and histology, distributed throughout the body. White adipose tissue, responsible for energy storage and more recently found to have endocrine and inflammation-modulatory activities, was historically thought to be the only type of fat present in adult humans. The recent demonstration of functional brown adipose tissue in adults, which is highly metabolic, shifted this paradigm. Additionally, recent studies demonstrate the ability of white adipose tissue to be induced toward the brown adipose phenotype - "beige" or "brite" adipose tissue - in a process referred to as "browning." While these adipose tissue depots are under investigation in the context of obesity, new evidence suggests a maladaptive role in other metabolic disturbances including cancer-associated cachexia, which is the topic of this review. This syndrome is multifactorial in nature and is an independent factor associated with poor prognosis. Here, we review the contributions of all three adipose depots - white, brown, and beige - to the development and progression of cancer-associated cachexia. Specifically, we focus on the local and systemic processes involving these adipose tissues that lead to increased energy expenditure and sustained negative energy balance. We highlight key findings from both animal and human studies and discuss areas within the field that need further exploration. Impact statement Cancer-associated cachexia (CAC) is a complex, multifactorial syndrome that negatively impacts patient quality of live and prognosis. This work reviews a component of CAC that lacks prior discussion: adipose tissue contributions. Uniquely, it discusses all three types of adipose tissue, white, beige, and brown, their interactions, and their contributions to the development and progression of CAC. Summarizing key bench and clinical studies, it provides information that will be useful to both basic and clinical researchers in designing experiments, studies, and clinical trials.

[Evaluation of Cepan Cream after 15 years of treatment of burn scars].

PubMed

Stozkowska, Wiesława

2002-01-01

Cepan Cream is used for the topical treatment of scars and keloids resulting from burns, post-operative scars, and contractures. Cepan Cream makes scars more elastic, softer and paler. Plant extracts, heparin and allantoin in Cepan act on the biochemical processes in the developing connective tissue, preventing the formation of hyperplastic scars. These active ingredients enhance swelling, softening and loosening of connective tissue. It exerts softening and smoothing action on indurated and hyperplastic scar tissue, improving collagen structure. It promotes tissue regeneration and reduces exuberant granulation. Cepan is well tolerated.

Developmental origin of lung macrophage diversity

PubMed Central

Tan, Serena Y. S.; Krasnow, Mark A.

2016-01-01

Macrophages are specialized phagocytic cells, present in all tissues, which engulf and digest pathogens, infected and dying cells, and debris, and can recruit and regulate other immune cells and the inflammatory response and aid in tissue repair. Macrophage subpopulations play distinct roles in these processes and in disease, and are typically recognized by differences in marker expression, immune function, or tissue of residency. Although macrophage subpopulations in the brain have been found to have distinct developmental origins, the extent to which development contributes to macrophage diversity between tissues and within tissues is not well understood. Here, we investigate the development and maintenance of mouse lung macrophages by marker expression patterns, genetic lineage tracing and parabiosis. We show that macrophages populate the lung in three developmental waves, each giving rise to a distinct lineage. These lineages express different markers, reside in different locations, renew in different ways, and show little or no interconversion. Thus, development contributes significantly to lung macrophage diversity and targets each lineage to a different anatomical domain. PMID:26952982

Embryo sac formation and early embryo development in Agave tequilana (Asparagaceae).

PubMed

González-Gutiérrez, Alejandra G; Gutiérrez-Mora, Antonia; Rodríguez-Garay, Benjamín

2014-01-01

Agave tequilana is an angiosperm species that belongs to the family Asparagaceae (formerly Agavaceae). Even though there is information regarding to some aspects related to the megagametogenesis of A. tequilana, this is the first report describing the complete process of megasporogenesis, megagametogenesis, the early embryo and endosperm development process in detail. The objective of this work was to study and characterize all the above processes and the distinctive morphological changes of the micropylar and chalazal extremes after fertilization in this species. The agave plant material for the present study was collected from commercial plantations in the state of Jalisco, Mexico. Ovules and immature seeds, previously fixed in FAA and kept in ethanol 70%, were stained based on a tissue clarification technique by using a Mayer's-Hematoxylin solution. The tissue clarification technique was successfully used for the characterization of the megasporogenesis, megagametogenesis, mature embryo sac formation, the early embryo and endosperm development processes by studying intact cells. The embryo sac of A. tequilana was confirmed to be of the monosporic Polygonum-type and an helobial endosperm formation. Also, the time-lapse of the developmental processes studied was recorded.

Image processing and 3D visualization in the interpretation of patterned injury of the skin

NASA Astrophysics Data System (ADS)

Oliver, William R.; Altschuler, Bruce R.

1995-09-01

The use of image processing is becoming increasingly important in the evaluation of violent crime. While much work has been done in the use of these techniques for forensic purposes outside of forensic pathology, its use in the pathologic examination of wounding has been limited. We are investigating the use of image processing in the analysis of patterned injuries and tissue damage. Our interests are currently concentrated on 1) the use of image processing techniques to aid the investigator in observing and evaluating patterned injuries in photographs, 2) measurement of the 3D shape characteristics of surface lesions, and 3) correlation of patterned injuries with deep tissue injury as a problem in 3D visualization. We are beginning investigations in data-acquisition problems for performing 3D scene reconstructions from the pathology perspective of correlating tissue injury to scene features and trace evidence localization. Our primary tool for correlation of surface injuries with deep tissue injuries has been the comparison of processed surface injury photographs with 3D reconstructions from antemortem CT and MRI data. We have developed a prototype robot for the acquisition of 3D wound and scene data.

Molecular controls of arterial morphogenesis

PubMed Central

Simons, Michael; Eichmann, Anne

2015-01-01

Formation of arterial vasculature, here termed arteriogenesis, is a central process in embryonic vascular development as well as in adult tissues. While the process of capillary formation, angiogenesis, is relatively well understood, much remains to be learned about arteriogenesis. Recent discoveries point to the key role played by vascular endothelial growth factor receptor 2 (VEGFR2) in control of this process and to newly identified control circuits that dramatically influence its activity. The latter can present particularly attractive targets for a new class of therapeutic agents capable of activation of this signaling cascade in a ligand-independent manner, thereby promoting arteriogenesis in diseased tissues. PMID:25953926

High-frequency ultrasonic imaging of growth and development in manufactured engineered oral mucosal tissue surfaces.

PubMed

Winterroth, Frank; Kato, Hiroko; Kuo, Shiuhyang; Feinberg, Stephen E; Hollister, Scott J; Fowlkes, J Brian; Hollman, Kyle W

2014-09-01

This study uses high-resolution ultrasound to examine the growth and development of engineered oral mucosal tissues manufactured under aseptic conditions. The specimens are a commercially available natural tissue scaffold, AlloDerm, and oral keratinocytes seeded onto AlloDerm to form an ex vivo-produced oral mucosal equivalent (EVPOME) suitable for intra-oral grafting. The seeded cells produce a keratinized protective upper layer that smooths out any remaining surface irregularities on the underlying AlloDerm. Two-dimensional acoustic imaging of unseeded AlloDerm and developing EVPOMEs was performed on each day of their growth and development, each tissue specimen being imaged under aseptic conditions (total time from seeding to maturation: 11 d). Ultrasonic monitoring offers us the ability to determine the constituents of the EVPOME that are responsible for changes in its mechanical behavior during the manufacturing process. Ultrasonic monitoring affords us an opportunity to non-invasively assess, in real time, tissue-engineered constructs before release for use in patient care. Copyright © 2014 World Federation for Ultrasound in Medicine & Biology. Published by Elsevier Inc. All rights reserved.

Apical and basal epitheliomuscular F-actin dynamics during Hydra bud evagination

PubMed Central

Aufschnaiter, Roland; Wedlich-Söldner, Roland; Zhang, Xiaoming

2017-01-01

ABSTRACT Bending of 2D cell sheets is a fundamental morphogenetic mechanism during animal development and reproduction. A critical player driving cell shape during tissue bending is the actin cytoskeleton. Much of our current knowledge about actin dynamics in whole organisms stems from studies of embryonic development in bilaterian model organisms. Here, we have analyzed actin-based processes during asexual bud evagination in the simple metazoan Hydra. We created transgenic Hydra strains stably expressing the actin marker Lifeact-GFP in either ectodermal or endodermal epitheliomuscular cells. We then combined live imaging with conventional phalloidin staining to directly follow actin reorganization. Bending of the Hydra epithelial double layer is initiated by a group of epitheliomuscular cells in the endodermal layer. These cells shorten their apical-basal axis and arrange their basal muscle processes in a circular configuration. We propose that this rearrangement generates the initial forces to bend the endoderm towards the ectoderm. Convergent tissue movement in both epithelial layers towards the centre of evagination then leads to elongation and extension of the bud along its new body axis. Tissue movement into the bud is associated with lateral intercalation of epithelial cells, remodelling of apical septate junctions, and rearrangement of basal muscle processes. The work presented here extends the analysis of morphogenetic mechanisms beyond embryonic tissues of model bilaterians. PMID:28630355

Development and characterization of a novel hydrogel adhesive for soft tissue applications

NASA Astrophysics Data System (ADS)

Sanders, Lindsey Kennedy

With laparoscopic and robotic surgical techniques advancing, the need for an injectable surgical adhesive is growing. To be effective, surgical adhesives for internal organs require bulk strength and compliance to avoid rips and tears, and adhesive strength to avoid leakage at the application site, while not hindering the natural healing process. Although a number of tissue adhesives and sealants approved by the FDA for surgical use are currently available, attaining a useful balance in all of these qualities has proven difficult, particularly when considering applications involving highly expandable tissue, such as bladder and lung. The long-term goal of this project is to develop a hydrogel-based tissue adhesive that provides proper mechanical properties to eliminate the need for sutures in various soft tissue applications. Tetronic (BASF), a 4-arm poly(propylene oxide)-poly(ethylene oxide) (PPO-PEO) block copolymer, has been selected as the base material for the adhesive hydrogel system. Solutions of Tetronic T1107 can support reverse thermal gelation at physiological temperatures, which can be combined with covalent crosslinking to achieve a "tandem gelation" process making it ideal for use as a tissue adhesive. The objective of this doctoral thesis research is to improve the performance of the hydrogel based tissue adhesive developed previously by Cho and co-workers by applying a multi-functionalization of Tetronic. Specifically, this research aimed to improve bonding strength of Tetronic tissue adhesive using bi-functional modification, incorporate hemostatic function to the bi-functional Tetronic hydrogel, and evaluate the safety of bi-functional Tetronic tissue adhesive both in vitro and in vivo. In summary, we have developed a fast-curing, mechanically strong hemostatic tissue adhesive that can control blood loss in wet conditions during wound treatment applications (bladder, liver and muscle). Specifically, the bi-functional Tetronic adhesive (TAS) with a proper blend ratio may be used to achieve an accurate balance in bulk and tissue bond strengths, as well as the compliance and durability for expandable organ application, such as the bladder. Incorporation of chitosan expanded the utility of the bi-functional modified T1107 (TAS) adhesive to tissue wounds on highly vascularized organs (e.g., liver, kidney). Further, we demonstrated that the modified Tetronic adhesive is biocompatible and safe for treatment of small soft tissue wounds on rat's muscle using FDA requirements. The current findings helped our understanding of the material and mechanical properties of the modified Tetronic adhesive and ultimately progress the field of surgical adhesives and sealants by providing a tunable adhesive system for various internal soft tissue wound applications.

Development of a data entry auditing protocol and quality assurance for a tissue bank database.

PubMed

Khushi, Matloob; Carpenter, Jane E; Balleine, Rosemary L; Clarke, Christine L

2012-03-01

Human transcription error is an acknowledged risk when extracting information from paper records for entry into a database. For a tissue bank, it is critical that accurate data are provided to researchers with approved access to tissue bank material. The challenges of tissue bank data collection include manual extraction of data from complex medical reports that are accessed from a number of sources and that differ in style and layout. As a quality assurance measure, the Breast Cancer Tissue Bank (http:\\\\www.abctb.org.au) has implemented an auditing protocol and in order to efficiently execute the process, has developed an open source database plug-in tool (eAuditor) to assist in auditing of data held in our tissue bank database. Using eAuditor, we have identified that human entry errors range from 0.01% when entering donor's clinical follow-up details, to 0.53% when entering pathological details, highlighting the importance of an audit protocol tool such as eAuditor in a tissue bank database. eAuditor was developed and tested on the Caisis open source clinical-research database; however, it can be integrated in other databases where similar functionality is required.

Nondestructive Techniques to Evaluate the Characteristics and Development of Engineered Cartilage

PubMed Central

Mansour, Joseph M.; Lee, Zhenghong; Welter, Jean F.

2016-01-01

In this review, methods for evaluating the properties of tissue engineered (TE) cartilage are described. Many of these have been developed for evaluating properties of native and osteoarthritic articular cartilage. However, with the increasing interest in engineering cartilage, specialized methods are needed for nondestructive evaluation of tissue while it is developing and after it is implanted. Such methods are needed, in part, due to the large inter- and intra-donor variability in the performance of the cellular component of the tissue, which remains a barrier to delivering reliable TE cartilage for implantation. Using conventional destructive tests, such variability makes it near-impossible to predict the timing and outcome of the tissue engineering process at the level of a specific piece of engineered tissue and also makes it difficult to assess the impact of changing tissue engineering regimens. While it is clear that the true test of engineered cartilage is its performance after it is implanted, correlation of pre and post implantation properties determined non-destructively in vitro and/or in vivo with performance should lead to predictive methods to improve quality-control and to minimize the chances of implanting inferior tissue. PMID:26817458

Tendon Tissue Engineering: Progress, Challenges, and Translation to the Clinic

PubMed Central

Shearn, Jason T.; Kinneberg, Kirsten R.C.; Dyment, Nathaniel A.; Galloway, Marc T.; Kenter, Keith; Wylie, Christopher; Butler, David L.

2013-01-01

The tissue engineering field has made great strides in understanding how different aspects of tissue engineered constructs (TECs) and the culture process affect final tendon repair. However, there remain significant challenges in developing strategies that will lead to a clinically effective and commercially successful product. In an effort to increase repair quality, a better understanding of normal development, and how it differs from adult tendon healing, may provide strategies to improve tissue engineering. As tendon tissue engineering continues to improve, the field needs to employ more clinically relevant models of tendon injury such as degenerative tendons. We need to translate successes to larger animal models to begin exploring the clinical implications of our treatments. By advancing the models used to validate our TECs, we can help convince our toughest customer, the surgeon, that our products will be clinically efficacious. As we address these challenges in musculoskeletal tissue engineering, the field still needs to address the commercialization of products developed in the laboratory. TEC commercialization faces numerous challenges because each injury and patient is unique. This review aims to provide tissue engineers with a summary of important issues related to engineering tendon repairs and potential strategies for producing clinically successful products. PMID:21625053

Esophageal tissue engineering: an in-depth review on scaffold design.

PubMed

Tan, J Y; Chua, C K; Leong, K F; Chian, K S; Leong, W S; Tan, L P

2012-01-01

Treatment of esophageal cancer often requires surgical procedures that involve removal. The current approaches to restore esophageal continuity however, are known to have limitations which may not result in full functional recovery. In theory, using a tissue engineered esophagus developed from the patient's own cells to replace the removed esophageal segment can be the ideal method of reconstruction. One of the key elements involved in the tissue engineering process is the scaffold which acts as a template for organization of cells and tissue development. While a number of scaffolds range from traditional non-biodegradable tubing to bioactive decellularized matrix have been proposed to engineer the esophagus in the past decade, results are still not yet favorable with many challenges relating to tissue quality need to be met improvements. The success of new esophageal tissue formation will ultimately depend on the success of the scaffold being able to meet the essential requirements specific to the esophageal tissue. Here, the design of the scaffold and its fabrication approaches are reviewed. In this paper, we review the current state of development in bioengineering the esophagus with particular emphasis on scaffold design. Copyright © 2011 Wiley Periodicals, Inc.

Processed xenogenic cartilage as innovative biomatrix for cartilage tissue engineering: effects on chondrocyte differentiation and function.

PubMed

Schwarz, Silke; Elsaesser, Alexander F; Koerber, Ludwig; Goldberg-Bockhorn, Eva; Seitz, Andreas M; Bermueller, Christian; Dürselen, Lutz; Ignatius, Anita; Breiter, Roman; Rotter, Nicole

2015-12-01

One key point in the development of new bioimplant matrices for the reconstruction and replacement of cartilage defects is to provide an adequate microenvironment to ensure chondrocyte migration and de novo synthesis of cartilage-specific extracellular matrix (ECM). A recently developed decellularization and sterilization process maintains the three-dimensional (3D) collagen structure of native septal cartilage while increasing matrix porosity, which is considered to be crucial for cartilage tissue engineering. Human primary nasal septal chondrocytes were amplified in monolayer culture and 3D-cultured on processed porcine nasal septal cartilage scaffolds. The influence of chondrogenic growth factors on neosynthesis of ECM proteins was examined at the protein and gene expression levels. Seeding experiments demonstrated that processed xenogenic cartilage matrices provide excellent environmental properties for human nasal septal chondrocytes with respect to cell adhesion, migration into the matrix and neosynthesis of cartilage-specific ECM proteins, such as collagen type II and aggrecan. Matrix biomechanical stability indicated that the constructs retrieve full stability and function during 3D culture for up to 42 days, proportional to collagen type II and GAG production. Thus, processed xenogenic cartilage offers a suitable environment for human nasal chondrocytes and has promising potential for cartilage tissue engineering in the head and neck region. Copyright © 2012 John Wiley & Sons, Ltd.

Image processing and 3D visualization in forensic pathologic examination

NASA Astrophysics Data System (ADS)

Oliver, William R.; Altschuler, Bruce R.

1996-02-01

The use of image processing is becoming increasingly important in the evaluation of violent crime. While much work has been done in the use of these techniques for forensic purposes outside of forensic pathology, its use in the pathologic examination of wounding has been limited. We are investigating the use of image processing and three-dimensional visualization in the analysis of patterned injuries and tissue damage. While image processing will never replace classical understanding and interpretation of how injuries develop and evolve, it can be a useful tool in helping an observer notice features in an image, may help provide correlation of surface to deep tissue injury, and provide a mechanism for the development of a metric for analyzing how likely it may be that a given object may have caused a given wound. We are also exploring methods of acquiring three-dimensional data for such measurements, which is the subject of a second paper.

Surgical stapling device–tissue interactions: what surgeons need to know to improve patient outcomes

PubMed Central

Chekan, Edward; Whelan, Richard L

2014-01-01

The introduction of both new surgical devices and reengineered existing devices leads to modifications in the way traditional tasks are carried out and allows for the development of new surgical techniques. Each new device has benefits and limitations in regards to tissue interactions that, if known, allow for optimal use. However, most surgeons are unaware of these attributes and, therefore, new device introduction creates a “knowledge gap” that is potentially dangerous. The goal of this review is to present a framework for the study of device– tissue interactions and to initiate the process of “filling in” the knowledge gap via the available literature. Surgical staplers, which are continually being developed, are the focus of this piece. The integrity of the staple line, which depends on adequate tissue compression, is the primary factor in creating a stable anastomosis. This review focuses on published studies that evaluated the creation of stable anastomoses in bariatric, thoracic, and colorectal procedures. Understanding how staplers interact with target tissues is key to improving patient outcomes. It is clear from this review that each tissue type presents unique challenges. The thickness of each tissue varies as do the intrinsic biomechanical properties that determine the ideal compressive force and prefiring compression time for each tissue type. The correct staple height will vary depending on these tissue-specific properties and the tissue pathology. These studies reinforce the universal theme that compression, staple height, tissue thickness, tissue compressibility, and tissue type must all be considered by the surgeon prior to choosing a stapler and cartridge. The surgeon’s experience, therefore, is a critical factor. Educational programs need to be established to inform and update surgeons on the characteristics of each stapler. It is hoped that the framework presented in this review will facilitate this process. PMID:25246812

Effects of processing parameters in thermally induced phase separation technique on porous architecture of scaffolds for bone tissue engineering.

PubMed

Akbarzadeh, Rosa; Yousefi, Azizeh-Mitra

2014-08-01

Tissue engineering makes use of 3D scaffolds to sustain three-dimensional growth of cells and guide new tissue formation. To meet the multiple requirements for regeneration of biological tissues and organs, a wide range of scaffold fabrication techniques have been developed, aiming to produce porous constructs with the desired pore size range and pore morphology. Among different scaffold fabrication techniques, thermally induced phase separation (TIPS) method has been widely used in recent years because of its potential to produce highly porous scaffolds with interconnected pore morphology. The scaffold architecture can be closely controlled by adjusting the process parameters, including polymer type and concentration, solvent composition, quenching temperature and time, coarsening process, and incorporation of inorganic particles. The objective of this review is to provide information pertaining to the effect of these parameters on the architecture and properties of the scaffolds fabricated by the TIPS technique. © 2014 Wiley Periodicals, Inc.

Applying macromolecular crowding to 3D bioprinting: fabrication of 3D hierarchical porous collagen-based hydrogel constructs.

PubMed

Ng, Wei Long; Goh, Min Hao; Yeong, Wai Yee; Naing, May Win

2018-02-27

Native tissues and/or organs possess complex hierarchical porous structures that confer highly-specific cellular functions. Despite advances in fabrication processes, it is still very challenging to emulate the hierarchical porous collagen architecture found in most native tissues. Hence, the ability to recreate such hierarchical porous structures would result in biomimetic tissue-engineered constructs. Here, a single-step drop-on-demand (DOD) bioprinting strategy is proposed to fabricate hierarchical porous collagen-based hydrogels. Printable macromolecule-based bio-inks (polyvinylpyrrolidone, PVP) have been developed and printed in a DOD manner to manipulate the porosity within the multi-layered collagen-based hydrogels by altering the collagen fibrillogenesis process. The experimental results have indicated that hierarchical porous collagen structures could be achieved by controlling the number of macromolecule-based bio-ink droplets printed on each printed collagen layer. This facile single-step bioprinting process could be useful for the structural design of collagen-based hydrogels for various tissue engineering applications.

Multiscale modeling of mucosal immune responses

PubMed Central

2015-01-01

Computational modeling techniques are playing increasingly important roles in advancing a systems-level mechanistic understanding of biological processes. Computer simulations guide and underpin experimental and clinical efforts. This study presents ENteric Immune Simulator (ENISI), a multiscale modeling tool for modeling the mucosal immune responses. ENISI's modeling environment can simulate in silico experiments from molecular signaling pathways to tissue level events such as tissue lesion formation. ENISI's architecture integrates multiple modeling technologies including ABM (agent-based modeling), ODE (ordinary differential equations), SDE (stochastic modeling equations), and PDE (partial differential equations). This paper focuses on the implementation and developmental challenges of ENISI. A multiscale model of mucosal immune responses during colonic inflammation, including CD4+ T cell differentiation and tissue level cell-cell interactions was developed to illustrate the capabilities, power and scope of ENISI MSM. Background Computational techniques are becoming increasingly powerful and modeling tools for biological systems are of greater needs. Biological systems are inherently multiscale, from molecules to tissues and from nano-seconds to a lifespan of several years or decades. ENISI MSM integrates multiple modeling technologies to understand immunological processes from signaling pathways within cells to lesion formation at the tissue level. This paper examines and summarizes the technical details of ENISI, from its initial version to its latest cutting-edge implementation. Implementation Object-oriented programming approach is adopted to develop a suite of tools based on ENISI. Multiple modeling technologies are integrated to visualize tissues, cells as well as proteins; furthermore, performance matching between the scales is addressed. Conclusion We used ENISI MSM for developing predictive multiscale models of the mucosal immune system during gut inflammation. Our modeling predictions dissect the mechanisms by which effector CD4+ T cell responses contribute to tissue damage in the gut mucosa following immune dysregulation. PMID:26329787

Adipose tissue transcriptome changes during obesity development in female dogs.

PubMed

Grant, Ryan W; Vester Boler, Brittany M; Ridge, Tonya K; Graves, Thomas K; Swanson, Kelly S

2011-03-29

During the development of obesity, adipose tissue undergoes major expansion and remodeling, but the biological processes involved in this transition are not well understood. The objective of this study was to analyze global gene expression profiles of adipose tissue in dogs, fed a high-fat diet, during the transition from a lean to obese phenotype. Nine female beagles (4.09 ± 0.64 yr; 8.48 ± 0.35 kg) were randomized to ad libitum feeding or body weight maintenance. Subcutaneous adipose tissue biopsy, blood, and dual x-ray absorptiometry measurements were collected at 0, 4, 8, 12, and 24 wk of feeding. Serum was analyzed for glucose, insulin, fructosamine, triglycerides, free fatty acids, adiponectin, and leptin. Formalin-fixed adipose tissue was used for determination of adipocyte size. Adipose RNA samples were hybridized to Affymetrix Canine 2.0 microarrays. Statistical analysis, using repeated-measures ANOVA, showed ad libitum feeding increased (P < 0.05) body weight (0 wk, 8.36 ± 0.34 kg; 24 wk, 14.64 ± 0.34 kg), body fat mass (0 wk, 1.36 ± 0.24 kg; 24 wk, 6.52 ± 0.24 kg), adipocyte size (0 wk, 114.66 ± 17.38 μm(2); 24 wk, 320.97 ± 0.18.17 μm(2)), and leptin (0 wk, 0.8 ± 1.0 ng/ml; 24 wk, 12.9 ± 1.0 ng/ml). Microarrays displayed 1,665 differentially expressed genes in adipose tissue as weight increased. Alterations were seen in adipose tissue homeostatic processes including metabolism, oxidative stress, mitochondrial homeostasis, and extracellular matrix. Adipose transcriptome changes highlight the dynamic and adaptive response to ad libitum feeding and obesity development.

Multiscale modeling of mucosal immune responses.

PubMed

Mei, Yongguo; Abedi, Vida; Carbo, Adria; Zhang, Xiaoying; Lu, Pinyi; Philipson, Casandra; Hontecillas, Raquel; Hoops, Stefan; Liles, Nathan; Bassaganya-Riera, Josep

2015-01-01

Computational techniques are becoming increasingly powerful and modeling tools for biological systems are of greater needs. Biological systems are inherently multiscale, from molecules to tissues and from nano-seconds to a lifespan of several years or decades. ENISI MSM integrates multiple modeling technologies to understand immunological processes from signaling pathways within cells to lesion formation at the tissue level. This paper examines and summarizes the technical details of ENISI, from its initial version to its latest cutting-edge implementation. Object-oriented programming approach is adopted to develop a suite of tools based on ENISI. Multiple modeling technologies are integrated to visualize tissues, cells as well as proteins; furthermore, performance matching between the scales is addressed. We used ENISI MSM for developing predictive multiscale models of the mucosal immune system during gut inflammation. Our modeling predictions dissect the mechanisms by which effector CD4+ T cell responses contribute to tissue damage in the gut mucosa following immune dysregulation.Computational modeling techniques are playing increasingly important roles in advancing a systems-level mechanistic understanding of biological processes. Computer simulations guide and underpin experimental and clinical efforts. This study presents ENteric Immune Simulator (ENISI), a multiscale modeling tool for modeling the mucosal immune responses. ENISI's modeling environment can simulate in silico experiments from molecular signaling pathways to tissue level events such as tissue lesion formation. ENISI's architecture integrates multiple modeling technologies including ABM (agent-based modeling), ODE (ordinary differential equations), SDE (stochastic modeling equations), and PDE (partial differential equations). This paper focuses on the implementation and developmental challenges of ENISI. A multiscale model of mucosal immune responses during colonic inflammation, including CD4+ T cell differentiation and tissue level cell-cell interactions was developed to illustrate the capabilities, power and scope of ENISI MSM.

The in vivo pharmacokinetics, tissue distribution and excretion investigation of mesaconine in rats and its in vitro intestinal absorption study using UPLC-MS/MS.

PubMed

Liu, Xiuxiu; Tang, Minghai; Liu, Taohong; Wang, Chunyan; Tang, Qiaoxin; Xiao, Yaxin; Yang, Ruixin; Chao, Ruobing

2017-12-27

1. Mesaconine, an ingredient from Aconitum carmichaelii Debx., has been proven to have cardiac effect. For further development and better pharmacological elucidation, the in vivo process and intestinal absorptive behavior of mesaconine should be investigated comprehensively. 2. An ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated for the quantitation of mesaconine in rat plasma, tissue homogenates, urine and feces to investigate the in vivo pharmacokinetic profiles, tissue distribution and excretion. The intestinal absorptive behavior of mesaconine was investigated using in vitro everted rat gut sac model. 3. Mesaconine was well distributed in tissues and a mass of unchanged form was detected in feces. It was difficultly absorbed into blood circulatory system after oral administration. The insufficient oral bioavailability of mesaconine may be mainly attributed to its low intestinal permeability due to a lack of lipophilicity. The absorption of mesaconine in rat's intestine is a first-order process with the passive diffusion mechanism.

Direct-write Bioprinting of Cell-laden Methacrylated Gelatin Hydrogels

PubMed Central

Bertassoni, Luiz E.; Cardoso, Juliana C.; Manoharan, Vijayan; Cristino, Ana L.; Bhise, Nupura S.; Araujo, Wesleyan A.; Zorlutuna, Pinar; Vrana, Nihal E.; Ghaemmaghami, Amir M.

2014-01-01

Fabrication of three dimensional (3D) organoids with controlled microarchitectures has been shown to enhance tissue functionality. Bioprinting can be used to precisely position cells and cell-laden materials to generate controlled tissue architecture. Therefore, it represents an exciting alternative for organ fabrication. Despite the rapid progress in the field, the development of printing processes that can be used to fabricate macroscale tissue constructs from ECM-derived hydrogels has remained a challenge. Here we report a strategy for bioprinting of photolabile cell-laden methacrylated gelatin (GelMA) hydrogels. We bioprinted cell-laden GelMA at concentrations ranging from 7 to 15% with varying cell densities and found a direct correlation between printability and the hydrogel mechanical properties. Furthermore, encapsulated HepG2 cells preserved cell viability for at least 8 days following the bioprinting process. In summary, this work presents a strategy for direct-write bioprinting of a cell-laden photolabile ECM-derived hydrogel, which may find widespread application for tissue engineering, organ printing and the development of 3D drug discovery platforms. PMID:24695367

A high-throughput semi-automated preparation for filtered synaptoneurosomes.

PubMed

Murphy, Kathryn M; Balsor, Justin; Beshara, Simon; Siu, Caitlin; Pinto, Joshua G A

2014-09-30

Synaptoneurosomes have become an important tool for studying synaptic proteins. The filtered synaptoneurosomes preparation originally developed by Hollingsworth et al. (1985) is widely used and is an easy method to prepare synaptoneurosomes. The hand processing steps in that preparation, however, are labor intensive and have become a bottleneck for current proteomic studies using synaptoneurosomes. For this reason, we developed new steps for tissue homogenization and filtration that transform the preparation of synaptoneurosomes to a high-throughput, semi-automated process. We implemented a standardized protocol with easy to follow steps for homogenizing multiple samples simultaneously using a FastPrep tissue homogenizer (MP Biomedicals, LLC) and then filtering all of the samples in centrifugal filter units (EMD Millipore, Corp). The new steps dramatically reduce the time to prepare synaptoneurosomes from hours to minutes, increase sample recovery, and nearly double enrichment for synaptic proteins. These steps are also compatible with biosafety requirements for working with pathogen infected brain tissue. The new high-throughput semi-automated steps to prepare synaptoneurosomes are timely technical advances for studies of low abundance synaptic proteins in valuable tissue samples. Copyright © 2014 Elsevier B.V. All rights reserved.

Nonmuscle Tissues Contribution to Cancer Cachexia

PubMed Central

Stemmler, Britta

2015-01-01

Cachexia is a syndrome associated with cancer, characterized by body weight loss, muscle and adipose tissue wasting, and inflammation, being often associated with anorexia. In spite of the fact that muscle tissue represents more than 40% of body weight and seems to be the main tissue involved in the wasting that occurs during cachexia, recent developments suggest that tissues/organs such as adipose (both brown and white), brain, liver, gut, and heart are directly involved in the cachectic process and may be responsible for muscle wasting. This suggests that cachexia is indeed a multiorgan syndrome. Bearing all this in mind, the aim of the present review is to examine the impact of nonmuscle tissues in cancer cachexia. PMID:26523094

How cancer shapes evolution, and how evolution shapes cancer

PubMed Central

Casás-Selves, Matias; DeGregori, James

2013-01-01

Evolutionary theories are critical for understanding cancer development at the level of species as well as at the level of cells and tissues, and for developing effective therapies. Animals have evolved potent tumor suppressive mechanisms to prevent cancer development. These mechanisms were initially necessary for the evolution of multi-cellular organisms, and became even more important as animals evolved large bodies and long lives. Indeed, the development and architecture of our tissues were evolutionarily constrained by the need to limit cancer. Cancer development within an individual is also an evolutionary process, which in many respects mirrors species evolution. Species evolve by mutation and selection acting on individuals in a population; tumors evolve by mutation and selection acting on cells in a tissue. The processes of mutation and selection are integral to the evolution of cancer at every step of multistage carcinogenesis, from tumor genesis to metastasis. Factors associated with cancer development, such as aging and carcinogens, have been shown to promote cancer evolution by impacting both mutation and selection processes. While there are therapies that can decimate a cancer cell population, unfortunately, cancers can also evolve resistance to these therapies, leading to the resurgence of treatment-refractory disease. Understanding cancer from an evolutionary perspective can allow us to appreciate better why cancers predominantly occur in the elderly, and why other conditions, from radiation exposure to smoking, are associated with increased cancers. Importantly, the application of evolutionary theory to cancer should engender new treatment strategies that could better control this dreaded disease. PMID:23705033

Three-Dimensional Optical Mapping of Nanoparticle Distribution in Intact Tissues.

PubMed

Sindhwani, Shrey; Syed, Abdullah Muhammad; Wilhelm, Stefan; Glancy, Dylan R; Chen, Yih Yang; Dobosz, Michael; Chan, Warren C W

2016-05-24

The role of tissue architecture in mediating nanoparticle transport, targeting, and biological effects is unknown due to the lack of tools for imaging nanomaterials in whole organs. Here, we developed a rapid optical mapping technique to image nanomaterials in intact organs ex vivo and in three-dimensions (3D). We engineered a high-throughput electrophoretic flow device to simultaneously transform up to 48 tissues into optically transparent structures, allowing subcellular imaging of nanomaterials more than 1 mm deep into tissues which is 25-fold greater than current techniques. A key finding is that nanomaterials can be retained in the processed tissue by chemical cross-linking of surface adsorbed serum proteins to the tissue matrix, which enables nanomaterials to be imaged with respect to cells, blood vessels, and other structures. We developed a computational algorithm to analyze and quantitatively map nanomaterial distribution. This method can be universally applied to visualize the distribution and interactions of materials in whole tissues and animals including such applications as the imaging of nanomaterials, tissue engineered constructs, and biosensors within their intact biological environment.

Neural and Decision Theoretic Approaches for the Automated Segmentation of Radiodense Tissue in Digitized Mammograms

NASA Astrophysics Data System (ADS)

Eckert, R.; Neyhart, J. T.; Burd, L.; Polikar, R.; Mandayam, S. A.; Tseng, M.

2003-03-01

Mammography is the best method available as a non-invasive technique for the early detection of breast cancer. The radiographic appearance of the female breast consists of radiolucent (dark) regions due to fat and radiodense (light) regions due to connective and epithelial tissue. The amount of radiodense tissue can be used as a marker for predicting breast cancer risk. Previously, we have shown that the use of statistical models is a reliable technique for segmenting radiodense tissue. This paper presents improvements in the model that allow for further development of an automated system for segmentation of radiodense tissue. The segmentation algorithm employs a two-step process. In the first step, segmentation of tissue and non-tissue regions of a digitized X-ray mammogram image are identified using a radial basis function neural network. The second step uses a constrained Neyman-Pearson algorithm, developed especially for this research work, to determine the amount of radiodense tissue. Results obtained using the algorithm have been validated by comparing with estimates provided by a radiologist employing previously established methods.

Mechanical Model of Geometric Cell and Topological Algorithm for Cell Dynamics from Single-Cell to Formation of Monolayered Tissues with Pattern

PubMed Central

Kachalo, Sëma; Naveed, Hammad; Cao, Youfang; Zhao, Jieling; Liang, Jie

2015-01-01

Geometric and mechanical properties of individual cells and interactions among neighboring cells are the basis of formation of tissue patterns. Understanding the complex interplay of cells is essential for gaining insight into embryogenesis, tissue development, and other emerging behavior. Here we describe a cell model and an efficient geometric algorithm for studying the dynamic process of tissue formation in 2D (e.g. epithelial tissues). Our approach improves upon previous methods by incorporating properties of individual cells as well as detailed description of the dynamic growth process, with all topological changes accounted for. Cell size, shape, and division plane orientation are modeled realistically. In addition, cell birth, cell growth, cell shrinkage, cell death, cell division, cell collision, and cell rearrangements are now fully accounted for. Different models of cell-cell interactions, such as lateral inhibition during the process of growth, can be studied in detail. Cellular pattern formation for monolayered tissues from arbitrary initial conditions, including that of a single cell, can also be studied in detail. Computational efficiency is achieved through the employment of a special data structure that ensures access to neighboring cells in constant time, without additional space requirement. We have successfully generated tissues consisting of more than 20,000 cells starting from 2 cells within 1 hour. We show that our model can be used to study embryogenesis, tissue fusion, and cell apoptosis. We give detailed study of the classical developmental process of bristle formation on the epidermis of D. melanogaster and the fundamental problem of homeostatic size control in epithelial tissues. Simulation results reveal significant roles of solubility of secreted factors in both the bristle formation and the homeostatic control of tissue size. Our method can be used to study broad problems in monolayered tissue formation. Our software is publicly available. PMID:25974182

Three-dimensional micro-scale strain mapping in living biological soft tissues.

PubMed

Moo, Eng Kuan; Sibole, Scott C; Han, Sang Kuy; Herzog, Walter

2018-04-01

Non-invasive characterization of the mechanical micro-environment surrounding cells in biological tissues at multiple length scales is important for the understanding of the role of mechanics in regulating the biosynthesis and phenotype of cells. However, there is a lack of imaging methods that allow for characterization of the cell micro-environment in three-dimensional (3D) space. The aims of this study were (i) to develop a multi-photon laser microscopy protocol capable of imprinting 3D grid lines onto living tissue at a high spatial resolution, and (ii) to develop image processing software capable of analyzing the resulting microscopic images and performing high resolution 3D strain analyses. Using articular cartilage as the biological tissue of interest, we present a novel two-photon excitation imaging technique for measuring the internal 3D kinematics in intact cartilage at sub-micrometer resolution, spanning length scales from the tissue to the cell level. Using custom image processing software, we provide accurate and robust 3D micro-strain analysis that allows for detailed qualitative and quantitative assessment of the 3D tissue kinematics. This novel technique preserves tissue structural integrity post-scanning, therefore allowing for multiple strain measurements at different time points in the same specimen. The proposed technique is versatile and opens doors for experimental and theoretical investigations on the relationship between tissue deformation and cell biosynthesis. Studies of this nature may enhance our understanding of the mechanisms underlying cell mechano-transduction, and thus, adaptation and degeneration of soft connective tissues. We presented a novel two-photon excitation imaging technique for measuring the internal 3D kinematics in intact cartilage at sub-micrometer resolution, spanning from tissue length scale to cellular length scale. Using a custom image processing software (lsmgridtrack), we provide accurate and robust micro-strain analysis that allowed for detailed qualitative and quantitative assessment of the 3D tissue kinematics. The approach presented here can also be applied to other biological tissues such as meniscus and annulus fibrosus, as well as tissue-engineered tissues for the characterization of their mechanical properties. This imaging technique opens doors for experimental and theoretical investigation on the relationship between tissue deformation and cell biosynthesis. Studies of this nature may enhance our understanding of the mechanisms underlying cell mechano-transduction, and thus, adaptation and degeneration of soft connective tissues. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Corneal donor tissue preparation for endothelial keratoplasty.

PubMed

Woodward, Maria A; Titus, Michael; Mavin, Kyle; Shtein, Roni M

2012-06-12

Over the past ten years, corneal transplantation surgical techniques have undergone revolutionary changes. Since its inception, traditional full thickness corneal transplantation has been the treatment to restore sight in those limited by corneal disease. Some disadvantages to this approach include a high degree of post-operative astigmatism, lack of predictable refractive outcome, and disturbance to the ocular surface. The development of Descemet's stripping endothelial keratoplasty (DSEK), transplanting only the posterior corneal stroma, Descemet's membrane, and endothelium, has dramatically changed treatment of corneal endothelial disease. DSEK is performed through a smaller incision; this technique avoids 'open sky' surgery with its risk of hemorrhage or expulsion, decreases the incidence of postoperative wound dehiscence, reduces unpredictable refractive outcomes, and may decrease the rate of transplant rejection. Initially, cornea donor posterior lamellar dissection for DSEK was performed manually resulting in variable graft thickness and damage to the delicate corneal endothelial tissue during tissue processing. Automated lamellar dissection (Descemet's stripping automated endothelial keratoplasty, DSAEK) was developed to address these issues. Automated dissection utilizes the same technology as LASIK corneal flap creation with a mechanical microkeratome blade that helps to create uniform and thin tissue grafts for DSAEK surgery with minimal corneal endothelial cell loss in tissue processing. Eye banks have been providing full thickness corneas for surgical transplantation for many years. In 2006, eye banks began to develop methodologies for supplying precut corneal tissue for endothelial keratoplasty. With the input of corneal surgeons, eye banks have developed thorough protocols to safely and effectively prepare posterior lamellar tissue for DSAEK surgery. This can be performed preoperatively at the eye bank. Research shows no significant difference in terms of the quality of the tissue or patient outcomes using eye bank precut tissue versus surgeon-prepared tissue for DSAEK surgery. For most corneal surgeons, the availability of precut DSAEK corneal tissue saves time and money, and reduces the stress of performing the donor corneal dissection in the operating room. In part because of the ability of the eye banks to provide high quality posterior lamellar corneal in a timely manner, DSAEK has become the standard of care for surgical management of corneal endothelial disease. The procedure that we are describing is the preparation of the posterior lamellar cornea at the eye bank for transplantation in DSAEK surgery (Figure 1).

Tissue architecture and breast cancer: the role of extracellular matrix and steroid hormones

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hansen, R K; Bissell, M J

The changes in tissue architecture that accompany the development of breast cancer have been the focus of investigations aimed at developing new cancer therapeutics. As we learn more about the normal mammary gland, we have begun to understand the complex signaling pathways underlying the dramatic shifts in the structure and function of breast tissue. Integrin-, growth factor-, and steroid hormone-signaling pathways all play an important part in maintaining tissue architecture; disruption of the delicate balance of signaling results in dramatic changes in the way cells interact with each other and with the extracellular matrix, leading to breast cancer. The extracellularmore » matrix itself plays a central role in coordinating these signaling processes. In this review, we consider the interrelationships between the extracellular matrix, integrins, growth factors, and steroid hormones in mammary gland development and function.« less

Socializing with MYC: cell competition in development and as a model for premalignant cancer.

PubMed

Johnston, Laura A

2014-04-01

Studies in Drosophila and mammals have made it clear that genetic mutations that arise in somatic tissues are rapidly recognized and eliminated, suggesting that cellular fitness is tightly monitored. During development, damaged, mutant, or otherwise unfit cells are prevented from contributing to the tissue and are instructed to die, whereas healthy cells benefit and populate the animal. This cell selection process, known as cell competition, eliminates somatic genetic heterogeneity and promotes tissue fitness during development. Yet cell competition also has a dark side. Super competition can be exploited by incipient cancers to subvert cellular cooperation and promote selfish behavior. Evidence is accumulating that MYC plays a key role in regulation of social behavior within tissues. Given the high number of tumors with deregulated MYC, studies of cell competition promise to yield insight into how the local environment yields to and participates in the early stages of tumor formation.

Tumor suppressors: enhancers or suppressors of regeneration?

PubMed Central

Pomerantz, Jason H.; Blau, Helen M.

2013-01-01

Tumor suppressors are so named because cancers occur in their absence, but these genes also have important functions in development, metabolism and tissue homeostasis. Here, we discuss known and potential functions of tumor suppressor genes during tissue regeneration, focusing on the evolutionarily conserved tumor suppressors pRb1, p53, Pten and Hippo. We propose that their activity is essential for tissue regeneration. This is in contrast to suggestions that tumor suppression is a trade-off for regenerative capacity. We also hypothesize that certain aspects of tumor suppressor pathways inhibit regenerative processes in mammals, and that transient targeted modification of these pathways could be fruitfully exploited to enhance processes that are important to regenerative medicine. PMID:23715544

Engineered heart tissues and induced pluripotent stem cells: Macro- and microstructures for disease modeling, drug screening, and translational studies.

PubMed

Tzatzalos, Evangeline; Abilez, Oscar J; Shukla, Praveen; Wu, Joseph C

2016-01-15

Engineered heart tissue has emerged as a personalized platform for drug screening. With the advent of induced pluripotent stem cell (iPSC) technology, patient-specific stem cells can be developed and expanded into an indefinite source of cells. Subsequent developments in cardiovascular biology have led to efficient differentiation of cardiomyocytes, the force-producing cells of the heart. iPSC-derived cardiomyocytes (iPSC-CMs) have provided potentially limitless quantities of well-characterized, healthy, and disease-specific CMs, which in turn has enabled and driven the generation and scale-up of human physiological and disease-relevant engineered heart tissues. The combined technologies of engineered heart tissue and iPSC-CMs are being used to study diseases and to test drugs, and in the process, have advanced the field of cardiovascular tissue engineering into the field of precision medicine. In this review, we will discuss current developments in engineered heart tissue, including iPSC-CMs as a novel cell source. We examine new research directions that have improved the function of engineered heart tissue by using mechanical or electrical conditioning or the incorporation of non-cardiomyocyte stromal cells. Finally, we discuss how engineered heart tissue can evolve into a powerful tool for therapeutic drug testing. Copyright © 2015 Elsevier B.V. All rights reserved.

Nanotechnology in vascular tissue engineering: from nanoscaffolding towards rapid vessel biofabrication.

PubMed

Mironov, Vladimir; Kasyanov, Vladimir; Markwald, Roger R

2008-06-01

The existing methods of biofabrication for vascular tissue engineering are still bioreactor-based, extremely expensive, laborious and time consuming and, furthermore, not automated, which would be essential for an economically successful large-scale commercialization. The advances in nanotechnology can bring additional functionality to vascular scaffolds, optimize internal vascular graft surface and even help to direct the differentiation of stem cells into the vascular cell phenotype. The development of rapid nanotechnology-based methods of vascular tissue biofabrication represents one of most important recent technological breakthroughs in vascular tissue engineering because it dramatically accelerates vascular tissue assembly and, importantly, also eliminates the need for a bioreactor-based scaffold cellularization process.

Optical pre-clinical diagnostics of the cervical tissues malignant changing

NASA Astrophysics Data System (ADS)

Yermolenko, Sergey; Voloshynskyi, Dmytro; Fedoruk, Olexander; Gruia, Ion; Zimnyakov, Dmitry

2014-08-01

This work is directed to the investigation of the scope of the technique of laser polarimetry of oncological changes of the human prostate and cervical tissues under the conditions of multiple scattering, which presents a more general and real experimental clinical situation. This study is combining polarimetry and spectropolarimetry techniques for identifying the changes of optical-geometrical structure in different kinds of biotissues with solid tumours. It is researched that a linear dichroism appears in biotissues (human esophagus, muscle tissue of rats, human prostate tissue, cervical smear) with cancer diseases, magnitude of which depends on the type of the tissue and on the time of cancer process development.

Computational Modeling of Tissue Self-Assembly

NASA Astrophysics Data System (ADS)

Neagu, Adrian; Kosztin, Ioan; Jakab, Karoly; Barz, Bogdan; Neagu, Monica; Jamison, Richard; Forgacs, Gabor

As a theoretical framework for understanding the self-assembly of living cells into tissues, Steinberg proposed the differential adhesion hypothesis (DAH) according to which a specific cell type possesses a specific adhesion apparatus that combined with cell motility leads to cell assemblies of various cell types in the lowest adhesive energy state. Experimental and theoretical efforts of four decades turned the DAH into a fundamental principle of developmental biology that has been validated both in vitro and in vivo. Based on computational models of cell sorting, we have developed a DAH-based lattice model for tissues in interaction with their environment and simulated biological self-assembly using the Monte Carlo method. The present brief review highlights results on specific morphogenetic processes with relevance to tissue engineering applications. Our own work is presented on the background of several decades of theoretical efforts aimed to model morphogenesis in living tissues. Simulations of systems involving about 105 cells have been performed on high-end personal computers with CPU times of the order of days. Studied processes include cell sorting, cell sheet formation, and the development of endothelialized tubes from rings made of spheroids of two randomly intermixed cell types, when the medium in the interior of the tube was different from the external one. We conclude by noting that computer simulations based on mathematical models of living tissues yield useful guidelines for laboratory work and can catalyze the emergence of innovative technologies in tissue engineering.

Long Noncoding RNAs: a New Regulatory Code in Metabolic Control

PubMed Central

Zhao, Xu-Yun; Lin, Jiandie D.

2015-01-01

Long noncoding RNAs (lncRNAs) are emerging as an integral part of the regulatory information encoded in the genome. LncRNAs possess the unique capability to interact with nucleic acids and proteins and exert discrete effects on numerous biological processes. Recent studies have delineated multiple lncRNA pathways that control metabolic tissue development and function. The expansion of the regulatory code that links nutrient and hormonal signals to tissue metabolism gives new insights into the genetic and pathogenic mechanisms underlying metabolic disease. This review discusses lncRNA biology with a focus on its role in the development, signaling, and function of key metabolic tissues. PMID:26410599

3D printed porous ceramic scaffolds for bone tissue engineering: a review.

PubMed

Wen, Yu; Xun, Sun; Haoye, Meng; Baichuan, Sun; Peng, Chen; Xuejian, Liu; Kaihong, Zhang; Xuan, Yang; Jiang, Peng; Shibi, Lu

2017-08-22

This study summarizes the recent research status and development of three-dimensional (3D)-printed porous ceramic scaffolds in bone tissue engineering. Recent literature on 3D-printed porous ceramic scaffolds was reviewed. Compared with traditional processing and manufacturing technologies, 3D-printed porous ceramic scaffolds have obvious advantages, such as enhancement of the controllability of the structure or improvement of the production efficiency. More sophisticated scaffolds were fabricated by 3D printing technology. 3D printed bioceramics have broad application prospects in bone tissue engineering. Through understanding the advantages and limitations of different 3D-printing approaches, new classes of bone graft substitutes can be developed.

Adult stem cell lineage tracing and deep tissue imaging

PubMed Central

Fink, Juergen; Andersson-Rolf, Amanda; Koo, Bon-Kyoung

2015-01-01

Lineage tracing is a widely used method for understanding cellular dynamics in multicellular organisms during processes such as development, adult tissue maintenance, injury repair and tumorigenesis. Advances in tracing or tracking methods, from light microscopy-based live cell tracking to fluorescent label-tracing with two-photon microscopy, together with emerging tissue clearing strategies and intravital imaging approaches have enabled scientists to decipher adult stem and progenitor cell properties in various tissues and in a wide variety of biological processes. Although technical advances have enabled time-controlled genetic labeling and simultaneous live imaging, a number of obstacles still need to be overcome. In this review, we aim to provide an in-depth description of the traditional use of lineage tracing as well as current strategies and upcoming new methods of labeling and imaging. [BMB Reports 2015; 48(12): 655-667] PMID:26634741

How Multi-Organ Microdevices Can Help Foster Drug Development

PubMed Central

Esch, Mandy B.; Smith, Alec; Prot, Jean-Matthieu; Sancho, Carlotta Oleaga; Hickman, James; Shuler, Michael L.

2014-01-01

Multi-organ microdevices can mimic tissue-tissue interactions that occur as a result of metabolite travel from one tissue to other tissues in vitro. These systems are capable of simulating human metabolism, including the conversion of a pro-drug to its effective metabolite as well as its subsequent therapeutic actions and toxic side effects. Since tissue-tissue interactions in the human body can play a significant role in determining the success of new pharmaceuticals, the development and use of multi-organ microdevices presents an opportunity to improve the drug development process. The goals are to predict potential toxic side effects with higher accuracy before a drug enters the expensive phase of clinical trials as well as to estimate efficacy and dose response. Multi-organ microdevices also have the potential to aid in the development of new therapeutic strategies by providing a platform for testing in the context of human metabolism (as opposed to animal models). Further, when operated with human biopsy samples, the devices could be a gateway for the development of individualized medicine. Here we review studies in which multi-organ microdevices have been developed and used in a ways that demonstrate how the devices’ capabilities can present unique opportunities for the study of drug action. We also discuss the challenges that are inherent in the development of multi-organ microdevices. Among these are how to design the devices, and how to create devices that mimic the human metabolism with high authenticity. Since single organ devices are testing platforms for tissues that can later be combined with other tissues within multi-organ devices, we will also mention single organ devices where appropriate in the discussion. PMID:24412641

Development of Assays for Detecting Significant Prostate Cancer Based on Molecular Alterations Associated with Cancer in Non-Neoplastic Prostate Tissue

DTIC Science & Technology

2015-10-01

with Cancer in Non-Neoplastic Prostate Tissue PRINCIPAL INVESTIGATOR: Farhad Kosari, Ph.D. CONTRACTING ORGANIZATION: Mayo Clinic Rochester, MN...E-Mail: kosari.farhad@mayo.edu 5f. WORK UNIT NUMBER 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) Mayo Clinic Rochester, MN 55905-0002 8...with the Tissue Request Acquisition Group (TRAG) at the Mayo Clinic , a process was implemented for the collection of resected prostates from

Biobanking human endometrial tissue and blood specimens: standard operating procedure and importance to reproductive biology research and diagnostic development.

PubMed

Sheldon, Elizabeth; Vo, Kim Chi; McIntire, Ramsey A; Aghajanova, Lusine; Zelenko, Zara; Irwin, Juan C; Giudice, Linda C

2011-05-01

To develop a standard operating procedure (SOP) for collection, transport, storage of human endometrial tissue and blood samples, subject and specimen annotation, and establishing sample priorities. The SOP synthesizes sound scientific procedures, the literature on ischemia research, sample collection and gene expression profiling, good laboratory practices, and the authors' experience of workflow and sample quality. The National Institutes of Health, University of California, San Francisco, Human Endometrial Tissue and DNA Bank. Women undergoing endometrial biopsy or hysterectomy for nonmalignant indications. Collecting, processing, storing, distributing endometrial tissue and blood samples under approved institutional review board protocols and written informed consent from participating subjects. Standard operating procedure. The SOP addresses rigorous and consistent subject annotation, specimen processing and characterization, strict regulatory compliance, and a reference for researchers to track collection and storage times that may influence their research. The comprehensive and systematic approach to the procurement of human blood and endometrial tissue in this SOP ensures the high quality, reliability, and scientific usefulness of biospecimens made available to investigators by the National Institutes of Health, University of California, San Francisco, Human Endometrial Tissue and DNA Bank. The detail and perspective in this SOP also provides a blueprint for implementation of similar collection programs at other institutions. Copyright © 2011 American Society for Reproductive Medicine. Published by Elsevier Inc. All rights reserved.

Epithelial Patterning, Morphogenesis, and Evolution: Drosophila Eggshell as a Model.

PubMed

Osterfield, Miriam; Berg, Celeste A; Shvartsman, Stanislav Y

2017-05-22

Understanding the mechanisms driving tissue and organ formation requires knowledge across scales. How do signaling pathways specify distinct tissue types? How does the patterning system control morphogenesis? How do these processes evolve? The Drosophila egg chamber, where EGF and BMP signaling intersect to specify unique cell types that construct epithelial tubes for specialized eggshell structures, has provided a tractable system to ask these questions. Work there has elucidated connections between scales of development, including across evolutionary scales, and fostered the development of quantitative modeling tools. These tools and general principles can be applied to the understanding of other developmental processes across organisms. Copyright © 2017 Elsevier Inc. All rights reserved.

Development of maternal seed tissue in barley is mediated by regulated cell expansion and cell disintegration and coordinated with endosperm growth.

PubMed

Radchuk, Volodymyr; Weier, Diana; Radchuk, Ruslana; Weschke, Winfriede; Weber, Hans

2011-01-01

After fertilization, filial grain organs are surrounded by the maternal nucellus embedded within the integuments and pericarp. Rapid early endosperm growth must be coordinated with maternal tissue development. Parameters of maternal tissue growth and development were analysed during early endosperm formation. In the pericarp, cell proliferation is accomplished around the time of fertilization, followed by cell elongation predominantly in longitudinal directions. The rapid cell expansion coincides with endosperm cellularization. Distribution of TUNEL (terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling)-positive nuclei reveals distinct patterns starting in the nucellus at anthesis and followed later by the inner cell rows of the pericarp, then spreading to the whole pericarp. The pattern suggests timely and spatially regulated programmed cell death (PCD) processes in maternal seed tissues. When the endosperm is coenocytic, PCD events are only observed within the nucellus. Thereby, remobilization of nucellar storage compounds by PCD could nourish the early developing endosperm when functional interconnections are absent between maternal and filial seed organs. Specific proteases promote PCD events. Characterization of the barley vacuolar processing enzyme (VPE) gene family identified seven gene members specifically expressed in the developing grain. HvVPE2a (known as nucellain) together with closely similar HvVPE2b and HvVPE2d might be involved in nucellar PCD. HvVPE4 is strongly cell specific for pericarp parenchyma. Correlative evidence suggests that HvVPE4 plays a role in PCD events in the pericarp. Possible functions of PCD in the maternal tissues imply a potential nutritive role or the relief of a physical restraint for endosperm growth. PCD could also activate post-phloem transport functions.

From natural bone grafts to tissue engineering therapeutics: Brainstorming on pharmaceutical formulative requirements and challenges.

PubMed

Baroli, Biancamaria

2009-04-01

Tissue engineering is an emerging multidisciplinary field of investigation focused on the regeneration of diseased or injured tissues through the delivery of appropriate molecular and mechanical signals. Therefore, bone tissue engineering covers all the attempts to reestablish a normal physiology or to speed up healing of bone in all musculoskeletal disorders and injuries that are lashing modern societies. This article attempts to give a pharmaceutical perspective on the production of engineered man-made bone grafts that are described as implantable tissue engineering therapeutics, and to highlight the importance of understanding bone composition and structure, as well as osteogenesis and bone healing processes, to improve the design and development of such implants. In addition, special emphasis is given to pharmaceutical aspects that are frequently minimized, but that, instead, may be useful for formulation developments and in vitro/in vivo correlations.

Biomaterial-mediated strategies targeting vascularization for bone repair.

PubMed

García, José R; García, Andrés J

2016-04-01

Repair of non-healing bone defects through tissue engineering strategies remains a challenging feat in the clinic due to the aversive microenvironment surrounding the injured tissue. The vascular damage that occurs following a bone injury causes extreme ischemia and a loss of circulating cells that contribute to regeneration. Tissue-engineered constructs aimed at regenerating the injured bone suffer from complications based on the slow progression of endogenous vascular repair and often fail at bridging the bone defect. To that end, various strategies have been explored to increase blood vessel regeneration within defects to facilitate both tissue-engineered and natural repair processes. Developments that induce robust vascularization will need to consolidate various parameters including optimization of embedded therapeutics, scaffold characteristics, and successful integration between the construct and the biological tissue. This review provides an overview of current strategies as well as new developments in engineering biomaterials to induce reparation of a functional vascular supply in the context of bone repair.

[Use of tissue engineering in the reconstruction of flexor tendon injuries of the hand].

PubMed

Bíró, Vilmos

2015-02-08

In his literary analysis, the author describes a novel method applied in the reconstruction of flexor tendon injuries of the hand. This procedure is named tissue engineering, and it is examined mainly under experimental circumstances. After definition of the method and descriptions of literary preliminaries the author discusses the healing process of the normal tendon tissue, then development of the scaffold, an important step of tissue engineering is described. After these topics the introduction of the pluripotent mesenchymal stem cells into the scaffold, and proliferation of these cells and development of the sliding systems are presented. The mechanical resisting ability of the formed tendon tissue is also discussed. Finally, the author concludes that as long as results of experimental research cannot be successfully applied into clinical practice, well-tried tendon reconstruction operations and high quality postoperative rehabilitation are needed.

A toolbox to explore the mechanics of living embryonic tissues

PubMed Central

Campàs, Otger

2016-01-01

The sculpting of embryonic tissues and organs into their functional morphologies involves the spatial and temporal regulation of mechanics at cell and tissue scales. Decades of in vitro work, complemented by some in vivo studies, have shown the relevance of mechanical cues in the control of cell behaviors that are central to developmental processes, but the lack of methodologies enabling precise, quantitative measurements of mechanical cues in vivo have hindered our understanding of the role of mechanics in embryonic development. Several methodologies are starting to enable quantitative studies of mechanics in vivo and in situ, opening new avenues to explore how mechanics contributes to shaping embryonic tissues and how it affects cell behavior within developing embryos. Here we review the present methodologies to study the role of mechanics in living embryonic tissues, considering their strengths and drawbacks as well as the conditions in which they are most suitable. PMID:27061360

A toolbox to explore the mechanics of living embryonic tissues.

PubMed

Campàs, Otger

2016-07-01

The sculpting of embryonic tissues and organs into their functional morphologies involves the spatial and temporal regulation of mechanics at cell and tissue scales. Decades of in vitro work, complemented by some in vivo studies, have shown the relevance of mechanical cues in the control of cell behaviors that are central to developmental processes, but the lack of methodologies enabling precise, quantitative measurements of mechanical cues in vivo have hindered our understanding of the role of mechanics in embryonic development. Several methodologies are starting to enable quantitative studies of mechanics in vivo and in situ, opening new avenues to explore how mechanics contributes to shaping embryonic tissues and how it affects cell behavior within developing embryos. Here we review the present methodologies to study the role of mechanics in living embryonic tissues, considering their strengths and drawbacks as well as the conditions in which they are most suitable. Copyright © 2016 Elsevier Ltd. All rights reserved.

Transcriptomic changes throughout post-hatch development in Gallus gallus pituitary

PubMed Central

Lamont, Susan J; Schmidt, Carl J

2016-01-01

The pituitary gland is a neuroendocrine organ that works closely with the hypothalamus to affect multiple processes within the body including the stress response, metabolism, growth and immune function. Relative tissue expression (rEx) is a transcriptome analysis method that compares the genes expressed in a particular tissue to the genes expressed in all other tissues with available data. Using rEx, the aim of this study was to identify genes that are uniquely or more abundantly expressed in the pituitary when compared to all other collected chicken tissues. We applied rEx to define genes enriched in the chicken pituitaries at days 21, 22 and 42 post-hatch. rEx analysis identified 25 genes shared between all time points, 295 genes shared between days 21 and 22 and 407 genes unique to day 42. The 25 genes shared by all time points are involved in morphogenesis and general nervous tissue development. The 295 shared genes between days 21 and 22 are involved in neurogenesis and nervous system development and differentiation. The 407 unique day 42 genes are involved in pituitary development, endocrine system development and other hormonally related gene ontology terms. Overall, rEx analysis indicates a focus on nervous system/tissue development at days 21 and 22. By day 42, in addition to nervous tissue development, there is expression of genes involved in the endocrine system, possibly for maturation and preparation for reproduction. This study defines the transcriptome of the chicken pituitary gland and aids in understanding the expressed genes critical to its function and maturation. PMID:27856505

The effect of sterilization on mechanical properties of soft tissue allografts.

PubMed

Conrad, Bryan P; Rappé, Matthew; Horodyski, MaryBeth; Farmer, Kevin W; Indelicato, Peter A

2013-09-01

One major concern regarding soft tissue allograft use in surgical procedures is the risk of disease transmission. Current techniques of tissue sterilization, such as irradiation have been shown to adversely affect the mechanical properties of soft tissues. Grafts processed using Biocleanse processing (a proprietary technique developed by Regeneration Technologies to sterilize human tissues) will have better biomechanical characteristics than tissues that have been irradiated. Fifteen pairs of cadaveric Achilles tendon allografts were obtained and separated into three groups of 10 each. Three treatment groups were: Biocleanse, Irradiated, and Control (untreated). Each specimen was tested to determine the biomechanical properties of the tissue. Specimens were cyclically preloaded and then loaded to failure in tension. During testing, load, displacement, and optical strain data were captured. Following testing, the cross sectional area of the tendons was determined. Tendons in the control group were found to have a higher extrinsic stiffness (slope of the load-deformation curve, p = .005), have a higher ultimate stress (force/cross sectional area, p = .006) and higher ultimate failure load (p = .003) than irradiated grafts. Biocleanse grafts were also found to be stiffer than irradiated grafts (p = .014) yet were not found to be statistically different from either irradiated or non-irradiated grafts in terms of load to failure. Biocleanse processing seems to be a viable alternative to irradiation for Achilles tendon allografts sterilization in terms of their biomechanical properties.

HPLC determination of strychnine and brucine in rat tissues and the distribution study of processed semen strychni.

PubMed

Chen, Jun; Hou, Ting; Fang, Yun; Chen, Zhi-peng; Liu, Xiao; Cai, Hao; Lu, Tu-lin; Yan, Guo-jun; Cai, Bao-chang

2011-01-01

A simple and low-cost HPLC method with UV absorbance detection was developed and validated to simultaneously determine strychnine and brucine, the most abundant alkaloids in the processed Semen Strychni, in rat tissues (kidney, liver, spleen, lung, heart, stomach, small intestine, brain and plasma). The tissue samples were treated with a simple liquid-liquid extraction prior to HPLC. The LOQs were in the range of 0.039-0.050 µg/ml for different tissue or plasma samples. The extraction recoveries varied from 71.63 to 98.79%. The linear range was 0.05-2 µg/ml with correlation coefficient of over 0.991. The intra- and inter-day precision was less than 15%. Then the method was used to measure the tissue distribution of strychnine and brucine after intravenous administration of 1 mg/kg crude alkaloids fraction (CAF) extracted from the processed Semen Strychni. The results revealed that strychnine and brucine possessed similar tissue distribution characterization. The highest level was observed in kidney, while the lowest level was found in brain. It was indicated that kidney might be the primary excretion organ of prototype strychnine and brucine. It was also deduced that strychnine and brucine had difficulty in crossing the blood-brain barrier. Furthermore, no long-term accumulation of strychnine and brucine was found in rat tissues.

Optimized protocol for quantitative multiple reaction monitoring-based proteomic analysis of formalin-fixed, paraffin embedded tissues

PubMed Central

Kennedy, Jacob J.; Whiteaker, Jeffrey R.; Schoenherr, Regine M.; Yan, Ping; Allison, Kimberly; Shipley, Melissa; Lerch, Melissa; Hoofnagle, Andrew N.; Baird, Geoffrey Stuart; Paulovich, Amanda G.

2016-01-01

Despite a clinical, economic, and regulatory imperative to develop companion diagnostics, precious few new biomarkers have been successfully translated into clinical use, due in part to inadequate protein assay technologies to support large-scale testing of hundreds of candidate biomarkers in formalin-fixed paraffin embedded (FFPE) tissues. While the feasibility of using targeted, multiple reaction monitoring-mass spectrometry (MRM-MS) for quantitative analyses of FFPE tissues has been demonstrated, protocols have not been systematically optimized for robust quantification across a large number of analytes, nor has the performance of peptide immuno-MRM been evaluated. To address this gap, we used a test battery approach coupled to MRM-MS with the addition of stable isotope labeled standard peptides (targeting 512 analytes) to quantitatively evaluate the performance of three extraction protocols in combination with three trypsin digestion protocols (i.e. 9 processes). A process based on RapiGest buffer extraction and urea-based digestion was identified to enable similar quantitation results from FFPE and frozen tissues. Using the optimized protocols for MRM-based analysis of FFPE tissues, median precision was 11.4% (across 249 analytes). There was excellent correlation between measurements made on matched FFPE and frozen tissues, both for direct MRM analysis (R2 = 0.94) and immuno-MRM (R2 = 0.89). The optimized process enables highly reproducible, multiplex, standardizable, quantitative MRM in archival tissue specimens. PMID:27462933

Tubing-Electrospinning: A One-Step Process for Fabricating Fibrous Matrices with Spatial, Chemical, and Mechanical Gradients.

PubMed

Kim, Jung-Suk; Im, Byung Gee; Jin, Gyuhyung; Jang, Jae-Hyung

2016-08-31

Guiding newly generated tissues in a gradient pattern, thereby precisely mimicking inherent tissue morphology and subsequently arranging the intimate networks between adjacent tissues, is essential to raise the technical levels of tissue engineering and facilitate its transition into the clinic. In this study, a straightforward electrospinning method (the tubing-electrospinning technique) was developed to create fibrous matrices readily with diverse gradient patterns and to induce patterned cellular responses. Gradient fibrous matrices can be produced simply by installing a series of polymer-containing lengths of tubing into an electrospinning circuit and sequentially processing polymers without a time lag. The loading of polymer samples with different characteristics, including concentration, wettability, and mechanical properties, into the tubing system enabled unique features in fibrous matrices, such as longitudinal gradients in fiber density, surface properties, and mechanical stiffness. The resulting fibrous gradients were shown to arrange cellular migration and residence in a gradient manner, thereby offering efficient cues to mediate patterned tissue formation. The one-step process using tubing-electrospinning apparatus can be used without significant modifications regardless of the type of fibrous gradient. Hence, the tubing-electrospinning system can serve as a platform that can be readily used by a wide-range of users to induce patterned tissue formation in a gradient manner, which will ultimately improve the functionality of tissue engineering scaffolds.

Fluorescence Molecular Tomography: Principles and Potential for Pharmaceutical Research

PubMed Central

Stuker, Florian; Ripoll, Jorge; Rudin, Markus

2011-01-01

Fluorescence microscopic imaging is widely used in biomedical research to study molecular and cellular processes in cell culture or tissue samples. This is motivated by the high inherent sensitivity of fluorescence techniques, the spatial resolution that compares favorably with cellular dimensions, the stability of the fluorescent labels used and the sophisticated labeling strategies that have been developed for selectively labeling target molecules. More recently, two and three-dimensional optical imaging methods have also been applied to monitor biological processes in intact biological organisms such as animals or even humans. These whole body optical imaging approaches have to cope with the fact that biological tissue is a highly scattering and absorbing medium. As a consequence, light propagation in tissue is well described by a diffusion approximation and accurate reconstruction of spatial information is demanding. While in vivo optical imaging is a highly sensitive method, the signal is strongly surface weighted, i.e., the signal detected from the same light source will become weaker the deeper it is embedded in tissue, and strongly depends on the optical properties of the surrounding tissue. Derivation of quantitative information, therefore, requires tomographic techniques such as fluorescence molecular tomography (FMT), which maps the three-dimensional distribution of a fluorescent probe or protein concentration. The combination of FMT with a structural imaging method such as X-ray computed tomography (CT) or Magnetic Resonance Imaging (MRI) will allow mapping molecular information on a high definition anatomical reference and enable the use of prior information on tissue's optical properties to enhance both resolution and sensitivity. Today many of the fluorescent assays originally developed for studies in cellular systems have been successfully translated for experimental studies in animals. The opportunity of monitoring molecular processes non-invasively in the intact organism is highly attractive from a diagnostic point of view but even more so for the drug developer, who can use the techniques for proof-of-mechanism and proof-of-efficacy studies. This review shall elucidate the current status and potential of fluorescence tomography including recent advances in multimodality imaging approaches for preclinical and clinical drug development. PMID:24310495

Optimized adipose tissue engineering strategy based on a neo-mechanical processing method.

PubMed

He, Yunfan; Lin, Maohui; Wang, Xuecen; Guan, Jingyan; Dong, Ziqing; Feng, Lu; Xing, Malcolm; Feng, Chuanbo; Li, Xiaojian

2018-05-26

Decellularized adipose tissue (DAT) represents a promising scaffold for adipose tissue engineering. However, the unique and prolonged lipid removal process required for adipose tissue can damage extracellular matrix (ECM) constituents. Moreover, inadequate vascularization limits the recellularization of DAT in vivo. We proposed a neo-mechanical protocol for rapidly breaking adipocytes and removing lipid content from adipose tissue. The lipid-depleted adipose tissue was then subjected to a fast and mild decellularization to fabricate high-quality DAT (M-DAT). Adipose liquid extract (ALE) derived from this mechanical process was collected and incorporated into M-DAT to further optimize in vivo recellularization. Ordinary DAT was fabricated and served as a control. This developed strategy was evaluated based on decellularization efficiency, ECM quality, and recellularization efficiency. Angiogenic factor components and angiogenic potential of ALE were evaluated in vivo and in vitro. M-DAT achieved the same decellularization efficiency, but exhibited better retention of ECM components and recellularization, compared to those with ordinary DAT. Protein quantification revealed considerable levels of angiogenic factors (basic fibroblast growth factor, epidermal growth factor, transforming growth factor-β1, and vascular endothelial growth factor) in ALE. ALE promoted tube formation in vitro and induced intense angiogenesis in M-DAT in vivo; furthermore, higher expression of the adipogenic factor PPARγ and greater numbers of adipocytes were evident following ALE treatment, compared to those in the M-DAT group. Mechanical processing of adipose tissue led to the production of high-quality M-DAT and angiogenic factor-enriched ALE. The combination of ALE and M-DAT could be a promising strategy for engineered adipose tissue construction. This article is protected by copyright. All rights reserved. © 2018 by the Wound Healing Society.

Algorithms and Results of Eye Tissues Differentiation Based on RF Ultrasound

PubMed Central

Jurkonis, R.; Janušauskas, A.; Marozas, V.; Jegelevičius, D.; Daukantas, S.; Patašius, M.; Paunksnis, A.; Lukoševičius, A.

2012-01-01

Algorithms and software were developed for analysis of B-scan ultrasonic signals acquired from commercial diagnostic ultrasound system. The algorithms process raw ultrasonic signals in backscattered spectrum domain, which is obtained using two time-frequency methods: short-time Fourier and Hilbert-Huang transformations. The signals from selected regions of eye tissues are characterized by parameters: B-scan envelope amplitude, approximated spectral slope, approximated spectral intercept, mean instantaneous frequency, mean instantaneous bandwidth, and parameters of Nakagami distribution characterizing Hilbert-Huang transformation output. The backscattered ultrasound signal parameters characterizing intraocular and orbit tissues were processed by decision tree data mining algorithm. The pilot trial proved that applied methods are able to correctly classify signals from corpus vitreum blood, extraocular muscle, and orbit tissues. In 26 cases of ocular tissues classification, one error occurred, when tissues were classified into classes of corpus vitreum blood, extraocular muscle, and orbit tissue. In this pilot classification parameters of spectral intercept and Nakagami parameter for instantaneous frequencies distribution of the 1st intrinsic mode function were found specific for corpus vitreum blood, orbit and extraocular muscle tissues. We conclude that ultrasound data should be further collected in clinical database to establish background for decision support system for ocular tissue noninvasive differentiation. PMID:22654643

Smart Polymeric Hydrogels for Cartilage Tissue Engineering: A Review on the Chemistry and Biological Functions.

PubMed

Eslahi, Niloofar; Abdorahim, Marjan; Simchi, Abdolreza

2016-11-14

Stimuli responsive hydrogels (SRHs) are attractive bioscaffolds for tissue engineering. The structural similarity of SRHs to the extracellular matrix (ECM) of many tissues offers great advantages for a minimally invasive tissue repair. Among various potential applications of SRHs, cartilage regeneration has attracted significant attention. The repair of cartilage damage is challenging in orthopedics owing to its low repair capacity. Recent advances include development of injectable hydrogels to minimize invasive surgery with nanostructured features and rapid stimuli-responsive characteristics. Nanostructured SRHs with more structural similarity to natural ECM up-regulate cell-material interactions for faster tissue repair and more controlled stimuli-response to environmental changes. This review highlights most recent advances in the development of nanostructured or smart hydrogels for cartilage tissue engineering. Different types of stimuli-responsive hydrogels are introduced and their fabrication processes through physicochemical procedures are reported. The applications and characteristics of natural and synthetic polymers used in SRHs are also reviewed with an outline on clinical considerations and challenges.

Influence of menopause on adipose tissue clock gene genotype and its relationship with metabolic syndrome in morbidly obese women

USDA-ARS?s Scientific Manuscript database

Menopausal women exhibit a loss of circadian coordination, a process that runs parallel with a redistribution of adipose tissue. However, the specific genetic mechanisms underlying these alterations have not been studied. Thus, the aim of the present study was to determine whether the development of...

Bioprinting for Neural Tissue Engineering.

PubMed

Knowlton, Stephanie; Anand, Shivesh; Shah, Twisha; Tasoglu, Savas

2018-01-01

Bioprinting is a method by which a cell-encapsulating bioink is patterned to create complex tissue architectures. Given the potential impact of this technology on neural research, we review the current state-of-the-art approaches for bioprinting neural tissues. While 2D neural cultures are ubiquitous for studying neural cells, 3D cultures can more accurately replicate the microenvironment of neural tissues. By bioprinting neuronal constructs, one can precisely control the microenvironment by specifically formulating the bioink for neural tissues, and by spatially patterning cell types and scaffold properties in three dimensions. We review a range of bioprinted neural tissue models and discuss how they can be used to observe how neurons behave, understand disease processes, develop new therapies and, ultimately, design replacement tissues. Copyright © 2017 Elsevier Ltd. All rights reserved.

Validation of a Radiography-Based Quantification Designed to Longitudinally Monitor Soft Tissue Calcification in Skeletal Muscle.

PubMed

Moore, Stephanie N; Hawley, Gregory D; Smith, Emily N; Mignemi, Nicholas A; Ihejirika, Rivka C; Yuasa, Masato; Cates, Justin M M; Liu, Xulei; Schoenecker, Jonathan G

2016-01-01

Soft tissue calcification, including both dystrophic calcification and heterotopic ossification, may occur following injury. These lesions have variable fates as they are either resorbed or persist. Persistent soft tissue calcification may result in chronic inflammation and/or loss of function of that soft tissue. The molecular mechanisms that result in the development and maturation of calcifications are uncertain. As a result, directed therapies that prevent or resorb soft tissue calcifications remain largely unsuccessful. Animal models of post-traumatic soft tissue calcification that allow for cost-effective, serial analysis of an individual animal over time are necessary to derive and test novel therapies. We have determined that a cardiotoxin-induced injury of the muscles in the posterior compartment of the lower extremity represents a useful model in which soft tissue calcification develops remote from adjacent bones, thereby allowing for serial analysis by plain radiography. The purpose of the study was to design and validate a method for quantifying soft tissue calcifications in mice longitudinally using plain radiographic techniques and an ordinal scoring system. Muscle injury was induced by injecting cardiotoxin into the posterior compartment of the lower extremity in mice susceptible to developing soft tissue calcification. Seven days following injury, radiographs were obtained under anesthesia. Multiple researchers applied methods designed to standardize post-image processing of digital radiographs (N = 4) and quantify soft tissue calcification (N = 6) in these images using an ordinal scoring system. Inter- and intra-observer agreement for both post-image processing and the scoring system used was assessed using weighted kappa statistics. Soft tissue calcification quantifications by the ordinal scale were compared to mineral volume measurements (threshold 450.7mgHA/cm3) determined by μCT. Finally, sample-size calculations necessary to discriminate between a 25%, 50%, 75%, and 100% difference in STiCSS score 7 days following burn/CTX induced muscle injury were determined. Precision analysis demonstrated substantial to good agreement for both post-image processing (κ = 0.73 to 0.90) and scoring (κ = 0.88 to 0.93), with low inter- and intra-observer variability. Additionally, there was a strong correlation in quantification of soft tissue calcification between the ordinal system and by mineral volume quantification by μCT (Spearman r = 0.83 to 0.89). The ordinal scoring system reliably quantified soft tissue calcification in a burn/CTX-induced soft tissue calcification model compared to non-injured controls (Mann-Whitney rank test: P = 0.0002, ***). Sample size calculations revealed that 6 mice per group would be required to detect a 50% difference in STiCSS score with a power of 0.8. Finally, the STiCSS was demonstrated to reliably quantify soft tissue calcification [dystrophic calcification and heterotopic ossification] by radiographic analysis, independent of the histopathological state of the mineralization. Radiographic analysis can discriminate muscle injury-induced soft tissue calcification from adjacent bone and follow its clinical course over time without requiring the sacrifice of the animal. While the STiCSS cannot identify the specific type of soft tissue calcification present, it is still a useful and valid method by which to quantify the degree of soft tissue calcification. This methodology allows for longitudinal measurements of soft tissue calcification in a single animal, which is relatively less expensive, less time-consuming, and exposes the animal to less radiation than in vivo μCT. Therefore, this high-throughput, longitudinal analytic method for quantifying soft tissue calcification is a viable alternative for the study of soft tissue calcification.

Validation of a Radiography-Based Quantification Designed to Longitudinally Monitor Soft Tissue Calcification in Skeletal Muscle

PubMed Central

Moore, Stephanie N.; Hawley, Gregory D.; Smith, Emily N.; Mignemi, Nicholas A.; Ihejirika, Rivka C.; Yuasa, Masato; Cates, Justin M. M.; Liu, Xulei; Schoenecker, Jonathan G.

2016-01-01

Introduction Soft tissue calcification, including both dystrophic calcification and heterotopic ossification, may occur following injury. These lesions have variable fates as they are either resorbed or persist. Persistent soft tissue calcification may result in chronic inflammation and/or loss of function of that soft tissue. The molecular mechanisms that result in the development and maturation of calcifications are uncertain. As a result, directed therapies that prevent or resorb soft tissue calcifications remain largely unsuccessful. Animal models of post-traumatic soft tissue calcification that allow for cost-effective, serial analysis of an individual animal over time are necessary to derive and test novel therapies. We have determined that a cardiotoxin-induced injury of the muscles in the posterior compartment of the lower extremity represents a useful model in which soft tissue calcification develops remote from adjacent bones, thereby allowing for serial analysis by plain radiography. The purpose of the study was to design and validate a method for quantifying soft tissue calcifications in mice longitudinally using plain radiographic techniques and an ordinal scoring system. Methods Muscle injury was induced by injecting cardiotoxin into the posterior compartment of the lower extremity in mice susceptible to developing soft tissue calcification. Seven days following injury, radiographs were obtained under anesthesia. Multiple researchers applied methods designed to standardize post-image processing of digital radiographs (N = 4) and quantify soft tissue calcification (N = 6) in these images using an ordinal scoring system. Inter- and intra-observer agreement for both post-image processing and the scoring system used was assessed using weighted kappa statistics. Soft tissue calcification quantifications by the ordinal scale were compared to mineral volume measurements (threshold 450.7mgHA/cm3) determined by μCT. Finally, sample-size calculations necessary to discriminate between a 25%, 50%, 75%, and 100% difference in STiCSS score 7 days following burn/CTX induced muscle injury were determined. Results Precision analysis demonstrated substantial to good agreement for both post-image processing (κ = 0.73 to 0.90) and scoring (κ = 0.88 to 0.93), with low inter- and intra-observer variability. Additionally, there was a strong correlation in quantification of soft tissue calcification between the ordinal system and by mineral volume quantification by μCT (Spearman r = 0.83 to 0.89). The ordinal scoring system reliably quantified soft tissue calcification in a burn/CTX-induced soft tissue calcification model compared to non-injured controls (Mann-Whitney rank test: P = 0.0002, ***). Sample size calculations revealed that 6 mice per group would be required to detect a 50% difference in STiCSS score with a power of 0.8. Finally, the STiCSS was demonstrated to reliably quantify soft tissue calcification [dystrophic calcification and heterotopic ossification] by radiographic analysis, independent of the histopathological state of the mineralization. Conclusions Radiographic analysis can discriminate muscle injury-induced soft tissue calcification from adjacent bone and follow its clinical course over time without requiring the sacrifice of the animal. While the STiCSS cannot identify the specific type of soft tissue calcification present, it is still a useful and valid method by which to quantify the degree of soft tissue calcification. This methodology allows for longitudinal measurements of soft tissue calcification in a single animal, which is relatively less expensive, less time-consuming, and exposes the animal to less radiation than in vivo μCT. Therefore, this high-throughput, longitudinal analytic method for quantifying soft tissue calcification is a viable alternative for the study of soft tissue calcification. PMID:27438007

FGF-Dependent, Context-Driven Role for FRS Adapters in the Early Telencephalon

PubMed Central

Gutin, Grigoriy; Blackwood, Christopher A.; Kamatkar, Nachiket G.; Lee, Kyung W.; Fishell, Gordon; Wang, Fen

2017-01-01

FGF signaling, an important component of intercellular communication, is required in many tissues throughout development to promote diverse cellular processes. Whether FGF receptors (FGFRs) accomplish such varied tasks in part by activating different intracellular transducers in different contexts remains unclear. Here, we used the developing mouse telencephalon as an example to study the role of the FRS adapters FRS2 and FRS3 in mediating the functions of FGFRs. Using tissue-specific and germline mutants, we examined the requirement of Frs genes in two FGFR-dependent processes. We found that Frs2 and Frs3 are together required for the differentiation of a subset of medial ganglionic eminence (MGE)-derived neurons, but are dispensable for the survival of early telencephalic precursor cells, in which any one of three FGFRs (FGFR1, FGFR2, or FGFR3) is sufficient for survival. Although FRS adapters are dispensable for ERK-1/2 activation, they are required for AKT activation within the subventricular zone of the developing MGE. Using an FRS2,3-binding site mutant of Fgfr1, we established that FRS adapters are necessary for mediating most or all FGFR1 signaling, not only in MGE differentiation, but also in cell survival, implying that other adapters mediate at least in part the signaling from FGFR2 and FGFR3. Our study provides an example of a contextual role for an intracellular transducer and contributes to our understanding of how FGF signaling plays diverse developmental roles. SIGNIFICANCE STATEMENT FGFs promote a range of developmental processes in many developing tissues and at multiple developmental stages. The mechanisms underlying this multifunctionality remain poorly defined in vivo. Using telencephalon development as an example, we show here that FRS adapters exhibit some selectivity in their requirement for mediating FGF receptor (FGFR) signaling and activating downstream mediators that depend on the developmental process, with a requirement in neuronal differentiation but not cell survival. Differential engagement of FRS and non-FRS intracellular adapters downstream of FGFRs could therefore in principle explain how FGFs play several distinct roles in other developing tissues and developmental stages. PMID:28483978

FGF-Dependent, Context-Driven Role for FRS Adapters in the Early Telencephalon.

PubMed

Nandi, Sayan; Gutin, Grigoriy; Blackwood, Christopher A; Kamatkar, Nachiket G; Lee, Kyung W; Fishell, Gordon; Wang, Fen; Goldfarb, Mitchell; Hébert, Jean M

2017-06-07

FGF signaling, an important component of intercellular communication, is required in many tissues throughout development to promote diverse cellular processes. Whether FGF receptors (FGFRs) accomplish such varied tasks in part by activating different intracellular transducers in different contexts remains unclear. Here, we used the developing mouse telencephalon as an example to study the role of the FRS adapters FRS2 and FRS3 in mediating the functions of FGFRs. Using tissue-specific and germline mutants, we examined the requirement of Frs genes in two FGFR-dependent processes. We found that Frs2 and Frs3 are together required for the differentiation of a subset of medial ganglionic eminence (MGE)-derived neurons, but are dispensable for the survival of early telencephalic precursor cells, in which any one of three FGFRs (FGFR1, FGFR2, or FGFR3) is sufficient for survival. Although FRS adapters are dispensable for ERK-1/2 activation, they are required for AKT activation within the subventricular zone of the developing MGE. Using an FRS2,3-binding site mutant of Fgfr1 , we established that FRS adapters are necessary for mediating most or all FGFR1 signaling, not only in MGE differentiation, but also in cell survival, implying that other adapters mediate at least in part the signaling from FGFR2 and FGFR3. Our study provides an example of a contextual role for an intracellular transducer and contributes to our understanding of how FGF signaling plays diverse developmental roles. SIGNIFICANCE STATEMENT FGFs promote a range of developmental processes in many developing tissues and at multiple developmental stages. The mechanisms underlying this multifunctionality remain poorly defined in vivo Using telencephalon development as an example, we show here that FRS adapters exhibit some selectivity in their requirement for mediating FGF receptor (FGFR) signaling and activating downstream mediators that depend on the developmental process, with a requirement in neuronal differentiation but not cell survival. Differential engagement of FRS and non-FRS intracellular adapters downstream of FGFRs could therefore in principle explain how FGFs play several distinct roles in other developing tissues and developmental stages. Copyright © 2017 the authors 0270-6474/17/375690-09$15.00/0.

Cellular and Molecular Changes in Orthodontic Tooth Movement

PubMed Central

Zainal Ariffin, Shahrul Hisham; Yamamoto, Zulham; Zainol Abidin, lntan Zarina; Megat Abdul Wahab, Rohaya; Zainal Ariffin, Zaidah

2011-01-01

Tooth movement induced by orthodontic treatment can cause sequential reactions involving the periodontal tissue and alveolar bone, resulting in the release of numerous substances from the dental tissues and surrounding structures. To better understand the biological processes involved in orthodontic treatment, improve treatment, and reduce adverse side effects, several of these substances have been proposed as biomarkers. Potential biological markers can be collected from different tissue samples, and suitable sampling is important to accurately reflect biological processes. This paper covers the tissue changes that are involved during orthodontic tooth movement such as at compression region (involving osteoblasts), tension region (involving osteoclasts), dental root, and pulp tissues. Besides, the involvement of stem cells and their development towards osteoblasts and osteoclasts during orthodontic treatment have also been explained. Several possible biomarkers representing these biological changes during specific phenomenon, that is, bone remodelling (formation and resorption), inflammation, and root resorption have also been proposed. The knowledge of these biomarkers could be used in accelerating orthodontic treatment. PMID:22125437

A Chemoenzymatic Histology Method for O-GlcNAc Detection.

PubMed

Aguilar, Aime Lopez; Hou, Xiaomeng; Wen, Liuqing; Wang, Peng G; Wu, Peng

2017-12-14

Modification of nuclear and cytoplasmic proteins by the addition or removal of O-GlcNAc dynamically impacts multiple biological processes. Here, we present the development of a chemoenzymatic histology method for the detection of O-GlcNAc in tissue specimens. We applied this method to screen murine organs, uncovering specific O-GlcNAc distribution patterns in different tissue structures. We then utilized our histology method for O-GlcNAc detection in human brain specimens from healthy donors and donors with Alzheimer's disease and found higher levels of O-GlcNAc in specimens from healthy donors. We also performed an analysis using a multiple cancer tissue array, uncovering different O-GlcNAc levels between healthy and cancerous tissues, as well as different O-GlcNAc cellular distributions within certain tissue specimens. This chemoenzymatic histology method therefore holds great potential for revealing the biology of O-GlcNAc in physiopathological processes. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A mathematical model and computational framework for three-dimensional chondrocyte cell growth in a porous tissue scaffold placed inside a bi-directional flow perfusion bioreactor.

PubMed

Shakhawath Hossain, Md; Bergstrom, D J; Chen, X B

2015-12-01

The in vitro chondrocyte cell culture for cartilage tissue regeneration in a perfusion bioreactor is a complex process. Mathematical modeling and computational simulation can provide important insights into the culture process, which would be helpful for selecting culture conditions to improve the quality of the developed tissue constructs. However, simulation of the cell culture process is a challenging task due to the complicated interaction between the cells and local fluid flow and nutrient transport inside the complex porous scaffolds. In this study, a mathematical model and computational framework has been developed to simulate the three-dimensional (3D) cell growth in a porous scaffold placed inside a bi-directional flow perfusion bioreactor. The model was developed by taking into account the two-way coupling between the cell growth and local flow field and associated glucose concentration, and then used to perform a resolved-scale simulation based on the lattice Boltzmann method (LBM). The simulation predicts the local shear stress, glucose concentration, and 3D cell growth inside the porous scaffold for a period of 30 days of cell culture. The predicted cell growth rate was in good overall agreement with the experimental results available in the literature. This study demonstrates that the bi-directional flow perfusion culture system can enhance the homogeneity of the cell growth inside the scaffold. The model and computational framework developed is capable of providing significant insight into the culture process, thus providing a powerful tool for the design and optimization of the cell culture process. © 2015 Wiley Periodicals, Inc.

Mineralization/Anti-Mineralization Networks in the Skin and Vascular Connective Tissues

PubMed Central

Li, Qiaoli; Uitto, Jouni

2014-01-01

Ectopic mineralization has been linked to several common clinical conditions with considerable morbidity and mortality. The mineralization processes, both metastatic and dystrophic, affect the skin and vascular connective tissues. There are several contributing metabolic and environmental factors that make uncovering of the precise pathomechanisms of these acquired disorders exceedingly difficult. Several relatively rare heritable disorders share phenotypic manifestations similar to those in common conditions, and, consequently, they serve as genetically controlled model systems to study the details of the mineralization process in peripheral tissues. This overview will highlight diseases with mineral deposition in the skin and vascular connective tissues, as exemplified by familial tumoral calcinosis, pseudoxanthoma elasticum, generalized arterial calcification of infancy, and arterial calcification due to CD73 deficiency. These diseases, and their corresponding mouse models, provide insight into the pathomechanisms of soft tissue mineralization and point to the existence of intricate mineralization/anti-mineralization networks in these tissues. This information is critical for understanding the pathomechanistic details of different mineralization disorders, and it has provided the perspective to develop pharmacological approaches to counteract the consequences of ectopic mineralization. PMID:23665350

[Biofabrication: new approaches for tissue regeneration].

PubMed

Horch, Raymund E; Weigand, Annika; Wajant, Harald; Groll, Jürgen; Boccaccini, Aldo R; Arkudas, Andreas

2018-04-01

The advent of Tissue Engineering (TE) in the early 1990ies was fostered by the increasing need for functional tissue and organ replacement. Classical TE was based on the combination of carrier matrices, cells and growth factors to reconstitute lost or damaged tissue and organs. Despite considerable results in vitro and in experimental settings the lack of early vascularization has hampered its translation into daily clinical practice so far. A new field of research, called "biofabrication" utilizing latest 3D printing technologies aims at hierarchically and spatially incorporating different cells, biomaterials and molecules into a matrix to alleviate a directed maturation of artificial tissue. A literature research of the relevant publications regarding biofabrication and bioprinting was performed using the PubMed data base. Relevant papers were selected and evaluated with secondary analysis of specific citations on the bioprinting techniques. 180 relevant papers containing the key words were identified and evaluated. Basic principles into the developing field of bioprinting technology could be discerned. Key elements comprise the high-throughput assembly of cells and the fabrication of complex and functional hierarchically organized tissue constructs. Five relevant technological principles for bioprinting were identified, such as stereolithography, extrusion-based printing, laser-assisted printing, inkjet-based printing and nano-bioprinting. The different technical methods of 3D printing were found to be associated with various positive but also negative effects on cells and proteins during the printing process. Research efforts in this field obviously aim towards the development of optimizing the so called bioinks and the printing technologies. This review details the evolution of the classical methods of TE in Regenerative Medicine into the evolving field of biofabrication by bioprinting. The advantages of 3D bioprinting over traditional tissue engineering techniques are based on the assembling of cells, biomaterials and biomolecules in a spatially controlled manner to reproduce native tissue macro-, micro- and nanoarchitectures, that can be utilized not only to potentially produce functional replacement tissues or organs but also to serve as new models for basic research. Mimicking the stromal microenvironment of tumor cells to study the process of tumor formation and progression, metastasis, angiogenesis and modulation of the associated processes is one of these applications under research. To this end a close collaboration of specialists from the fields of engineering, biomaterial science, cell biology and reconstructive microsurgery will be necessary to develop future strategies that can overcome current limitations of tissue generation. © Georg Thieme Verlag KG Stuttgart · New York.

Using cell deformation and motion to predict forces and collective behavior in morphogenesis.

PubMed

Merkel, Matthias; Manning, M Lisa

2017-07-01

In multi-cellular organisms, morphogenesis translates processes at the cellular scale into tissue deformation at the scale of organs and organisms. To understand how biochemical signaling regulates tissue form and function, we must understand the mechanical forces that shape cells and tissues. Recent progress in developing mechanical models for tissues has led to quantitative predictions for how cell shape changes and polarized cell motility generate forces and collective behavior on the tissue scale. In particular, much insight has been gained by thinking about biological tissues as physical materials composed of cells. Here we review these advances and discuss how they might help shape future experiments in developmental biology. Copyright © 2016 Elsevier Ltd. All rights reserved.

Biomechanics and mechanobiology in functional tissue engineering

PubMed Central

Guilak, Farshid; Butler, David L.; Goldstein, Steven A.; Baaijens, Frank P.T.

2014-01-01

The field of tissue engineering continues to expand and mature, and several products are now in clinical use, with numerous other preclinical and clinical studies underway. However, specific challenges still remain in the repair or regeneration of tissues that serve a predominantly biomechanical function. Furthermore, it is now clear that mechanobiological interactions between cells and scaffolds can critically influence cell behavior, even in tissues and organs that do not serve an overt biomechanical role. Over the past decade, the field of “functional tissue engineering” has grown as a subfield of tissue engineering to address the challenges and questions on the role of biomechanics and mechanobiology in tissue engineering. Originally posed as a set of principles and guidelines for engineering of load-bearing tissues, functional tissue engineering has grown to encompass several related areas that have proven to have important implications for tissue repair and regeneration. These topics include measurement and modeling of the in vivo biomechanical environment; quantitative analysis of the mechanical properties of native tissues, scaffolds, and repair tissues; development of rationale criteria for the design and assessment of engineered tissues; investigation of the effects biomechanical factors on native and repair tissues, in vivo and in vitro; and development and application of computational models of tissue growth and remodeling. Here we further expand this paradigm and provide examples of the numerous advances in the field over the past decade. Consideration of these principles in the design process will hopefully improve the safety, efficacy, and overall success of engineered tissue replacements. PMID:24818797

Cell wall structures leading to cultivar differences in softening rates develop early during apple (Malus x domestica) fruit growth.

PubMed

Ng, Jovyn K T; Schröder, Roswitha; Sutherland, Paul W; Hallett, Ian C; Hall, Miriam I; Prakash, Roneel; Smith, Bronwen G; Melton, Laurence D; Johnston, Jason W

2013-11-19

There is a paucity of information regarding development of fruit tissue microstructure and changes in the cell walls during fruit growth, and how these developmental processes differ between cultivars with contrasting softening behaviour. In this study we compare two apple cultivars that show different softening rates during fruit development and ripening. We investigate whether these different softening behaviours manifest themselves late during ethylene-induced softening in the ripening phase, or early during fruit expansion and maturation. 'Scifresh' (slow softening) and 'Royal Gala' (rapid softening) apples show differences in cortical microstructure and cell adhesion as early as the cell expansion phase. 'Scifresh' apples showed reduced loss of firmness and greater dry matter accumulation compared with 'Royal Gala' during early fruit development, suggesting differences in resource allocation that influence tissue structural properties. Tricellular junctions in 'Scifresh' were rich in highly-esterified pectin, contributing to stronger cell adhesion and an increased resistance to the development of large airspaces during cell expansion. Consequently, mature fruit of 'Scifresh' showed larger, more angular shaped cells than 'Royal Gala', with less airspaces and denser tissue. Stronger cell adhesion in ripe 'Scifresh' resulted in tissue fracture by cell rupture rather than by cell-to-cell-separation as seen in 'Royal Gala'. CDTA-soluble pectin differed in both cultivars during development, implicating its involvement in cell adhesion. Low pectin methylesterase activity during early stages of fruit development coupled with the lack of immuno-detectable PG was associated with increased cell adhesion in 'Scifresh'. Our results indicate that cell wall structures leading to differences in softening rates of apple fruit develop early during fruit growth and well before the induction of the ripening process.

Cell wall structures leading to cultivar differences in softening rates develop early during apple (Malus x domestica) fruit growth

PubMed Central

2013-01-01

Background There is a paucity of information regarding development of fruit tissue microstructure and changes in the cell walls during fruit growth, and how these developmental processes differ between cultivars with contrasting softening behaviour. In this study we compare two apple cultivars that show different softening rates during fruit development and ripening. We investigate whether these different softening behaviours manifest themselves late during ethylene-induced softening in the ripening phase, or early during fruit expansion and maturation. Results ‘Scifresh’ (slow softening) and ‘Royal Gala’ (rapid softening) apples show differences in cortical microstructure and cell adhesion as early as the cell expansion phase. ‘Scifresh’ apples showed reduced loss of firmness and greater dry matter accumulation compared with ‘Royal Gala’ during early fruit development, suggesting differences in resource allocation that influence tissue structural properties. Tricellular junctions in ‘Scifresh’ were rich in highly-esterified pectin, contributing to stronger cell adhesion and an increased resistance to the development of large airspaces during cell expansion. Consequently, mature fruit of ‘Scifresh’ showed larger, more angular shaped cells than ‘Royal Gala’, with less airspaces and denser tissue. Stronger cell adhesion in ripe ‘Scifresh’ resulted in tissue fracture by cell rupture rather than by cell-to-cell-separation as seen in ‘Royal Gala’. CDTA-soluble pectin differed in both cultivars during development, implicating its involvement in cell adhesion. Low pectin methylesterase activity during early stages of fruit development coupled with the lack of immuno-detectable PG was associated with increased cell adhesion in ‘Scifresh’. Conclusions Our results indicate that cell wall structures leading to differences in softening rates of apple fruit develop early during fruit growth and well before the induction of the ripening process. PMID:24252512

Molecular controls of arterial morphogenesis.

PubMed

Simons, Michael; Eichmann, Anne

2015-05-08

Formation of arterial vasculature, here termed arteriogenesis, is a central process in embryonic vascular development as well as in adult tissues. Although the process of capillary formation, angiogenesis, is relatively well understood, much remains to be learned about arteriogenesis. Recent discoveries point to the key role played by vascular endothelial growth factor receptor 2 in control of this process and to newly identified control circuits that dramatically influence its activity. The latter can present particularly attractive targets for a new class of therapeutic agents capable of activation of this signaling cascade in a ligand-independent manner, thereby promoting arteriogenesis in diseased tissues. © 2015 American Heart Association, Inc.

Modeling formalin fixation and histological processing with ribonuclease A: effects of ethanol dehydration on reversal of formaldehyde cross-links.

PubMed

Fowler, Carol B; O'Leary, Timothy J; Mason, Jeffrey T

2008-07-01

Understanding the chemistry of protein modification by formaldehyde fixation and subsequent tissue processing is central to developing improved methods for antigen retrieval in immunohistochemistry and for recovering proteins from formalin-fixed, paraffin-embedded (FFPE) tissues for proteomic analysis. Our initial studies of single proteins, such as bovine pancreatic ribonuclease A (RNase A), in 10% buffered formalin solution revealed that upon removal of excess formaldehyde, monomeric RNase A exhibiting normal immunoreactivity could be recovered by heating at 60 degrees C for 30 min at pH 4. We next studied tissue surrogates, which are gelatin-like plugs of fixed proteins that have sufficient physical integrity to be processed using normal tissue histology. Following histological processing, proteins could be extracted from the tissue surrogates by combining heat, detergent, and a protein denaturant. However, gel electrophoresis revealed that the surrogate extracts contained a mixture of monomeric and multimeric proteins. This suggested that during the subsequent steps of tissue processing protein-formaldehyde adducts undergo further modifications that are not observed in aqueous proteins. As a first step toward understanding these additional modifications we have performed a comparative evaluation of RNase A following fixation in buffered formaldehyde alone and after subsequent dehydration in 100% ethanol by combining gel electrophoresis, chemical modification, and circular dichroism spectroscopic studies. Our results reveal that ethanol-induced rearrangement of the conformation of fixed RNase A leads to protein aggregation through the formation of large geometrically compatible hydrophobic beta-sheets that are likely stabilized by formaldehyde cross-links, hydrogen bonds, and van der Waals interactions. It requires substantial energy to reverse the formaldehyde cross-links within these sheets and regenerate protein monomers free of formaldehyde modifications. Accordingly, the ethanol-dehydration step in tissue histology may be important in confounding the successful recovery of proteins from FFPE tissues for immunohistochemical and proteomic analysis.

Inflammation Fuels Tumor Progress and Metastasis

PubMed Central

Liu, Jingyi; Lin, Pengnian Charles; Zhou, Binhua P.

2017-01-01

Inflammation is a beneficial response that can remove pathogens, repair injured tissue and restore homeostasis to damaged tissues and organs. However, increasing evidence indicate that chronic inflammation plays a pivotal role in tumor development, as well as progression, metastasis, and resistance to chemotherapy. We will review the current knowledge regarding the contribution of inflammation to epithelial mesenchymal transition. We will also provide some perspectives on the relationship between ER-stress signals and metabolism, and the role of these processes in the development of inflammation. PMID:26004407

Growth factor involvement in tension-induced skeletal muscle growth

NASA Technical Reports Server (NTRS)

Vandenburgh, H. H.

1987-01-01

Muscle tissue culture techniques were developed to grow skeletal myofibers which differentiate into more adult-like myofibers. Mechanical simulation studies of these muscle cells in a newly developed mechanical cell simulator can now be performed to study growth processes in skeletal muscle. Conditions in the mechanical cell simulator were defined where mechanical activity can either prevent muscle wasting or stimulate muscle growth. The role of endogenous and exogenous growth factors in tension-induced muscle growth is being investigated under the defined conditions of tissue culture.

The CREST Simulation Development Process: Training the Next Generation.

PubMed

Sweet, Robert M

2017-04-01

The challenges of training and assessing endourologic skill have driven the development of new training systems. The Center for Research in Education and Simulation Technologies (CREST) has developed a team and a methodology to facilitate this development process. Backwards design principles were applied. A panel of experts first defined desired clinical and educational outcomes. Outcomes were subsequently linked to learning objectives. Gross task deconstruction was performed, and the primary domain was classified as primarily involving decision-making, psychomotor skill, or communication. A more detailed cognitive task analysis was performed to elicit and prioritize relevant anatomy/tissues, metrics, and errors. Reference anatomy was created using a digital anatomist and clinician working off of a clinical data set. Three dimensional printing can facilitate this process. When possible, synthetic or virtual tissue behavior and textures were recreated using data derived from human tissue. Embedded sensors/markers and/or computer-based systems were used to facilitate the collection of objective metrics. A learning Verification and validation occurred throughout the engineering development process. Nine endourology-relevant training systems were created by CREST with this approach. Systems include basic laparoscopic skills (BLUS), vesicourethral anastomosis, pyeloplasty, cystoscopic procedures, stent placement, rigid and flexible ureteroscopy, GreenLight PVP (GL Sim), Percutaneous access with C-arm (CAT), Nephrolithotomy (NLM), and a vascular injury model. Mixed modalities have been used, including "smart" physical models, virtual reality, augmented reality, and video. Substantial validity evidence for training and assessment has been collected on systems. An open source manikin-based modular platform is under development by CREST with the Department of Defense that will unify these and other commercial task trainers through the common physiology engine, learning management system, standard data connectors, and standards. Using the CREST process has and will ensure that the systems we create meet the needs of training and assessing endourologic skills.

Harnessing biomechanics to develop cartilage regeneration strategies.

PubMed

Athanasiou, Kyriacos A; Responte, Donald J; Brown, Wendy E; Hu, Jerry C

2015-02-01

As this review was prepared specifically for the American Society of Mechanical Engineers H.R. Lissner Medal, it primarily discusses work toward cartilage regeneration performed in Dr. Kyriacos A. Athanasiou's laboratory over the past 25 years. The prevalence and severity of degeneration of articular cartilage, a tissue whose main function is largely biomechanical, have motivated the development of cartilage tissue engineering approaches informed by biomechanics. This article provides a review of important steps toward regeneration of articular cartilage with suitable biomechanical properties. As a first step, biomechanical and biochemical characterization studies at the tissue level were used to provide design criteria for engineering neotissues. Extending this work to the single cell and subcellular levels has helped to develop biochemical and mechanical stimuli for tissue engineering studies. This strong mechanobiological foundation guided studies on regenerating hyaline articular cartilage, the knee meniscus, and temporomandibular joint (TMJ) fibrocartilage. Initial tissue engineering efforts centered on developing biodegradable scaffolds for cartilage regeneration. After many years of studying scaffold-based cartilage engineering, scaffoldless approaches were developed to address deficiencies of scaffold-based systems, resulting in the self-assembling process. This process was further improved by employing exogenous stimuli, such as hydrostatic pressure, growth factors, and matrix-modifying and catabolic agents, both singly and in synergistic combination to enhance neocartilage functional properties. Due to the high cell needs for tissue engineering and the limited supply of native articular chondrocytes, costochondral cells are emerging as a suitable cell source. Looking forward, additional cell sources are investigated to render these technologies more translatable. For example, dermis isolated adult stem (DIAS) cells show potential as a source of chondrogenic cells. The challenging problem of enhanced integration of engineered cartilage with native cartilage is approached with both familiar and novel methods, such as lysyl oxidase (LOX). These diverse tissue engineering strategies all aim to build upon thorough biomechanical characterizations to produce functional neotissue that ultimately will help combat the pressing problem of cartilage degeneration. As our prior research is reviewed, we look to establish new pathways to comprehensively and effectively address the complex problems of musculoskeletal cartilage regeneration.

Tissue specific localization of pectin-Ca²⁺ cross-linkages and pectin methyl-esterification during fruit ripening in tomato (Solanum lycopersicum).

PubMed

Hyodo, Hiromi; Terao, Azusa; Furukawa, Jun; Sakamoto, Naoya; Yurimoto, Hisayoshi; Satoh, Shinobu; Iwai, Hiroaki

2013-01-01

Fruit ripening is one of the developmental processes accompanying seed development. The tomato is a well-known model for studying fruit ripening and development, and the disassembly of primary cell walls and the middle lamella, such as through pectin de-methylesterified by pectin methylesterase (PE) and depolymerization by polygalacturonase (PG), is generally accepted to be one of the major changes that occur during ripening. Although many reports of the changes in pectin during tomato fruit ripening are focused on the relation to softening of the pericarp or the Blossom-end rot by calcium (Ca²⁺) deficiency disorder, the changes in pectin structure and localization in each tissues during tomato fruit ripening is not well known. In this study, to elucidate the tissue-specific role of pectin during fruit development and ripening, we examined gene expression, the enzymatic activities involved in pectin synthesis and depolymerisation in fruit using biochemical and immunohistochemical analyses, and uronic acids and calcium (Ca)-bound pectin were determined by secondary ion-microprobe mass spectrometry. These results show that changes in pectin properties during fruit development and ripening have tissue-specific patterns. In particular, differential control of pectin methyl-esterification occurs in each tissue. Variations in the cell walls of the pericarp are quite different from that of locular tissues. The Ca-binding pectin and hairy pectin in skin cell layers are important for intercellular and tissue-tissue adhesion. Maintenance of the globular form and softening of tomato fruit may be regulated by the arrangement of pectin structures in each tissue.

The implementation of tissue banking experiences for setting up a cGMP cell manufacturing facility.

PubMed

Arjmand, Babak; Emami-Razavi, Seyed Hassan; Larijani, Bagher; Norouzi-Javidan, Abbas; Aghayan, Hamid Reza

2012-12-01

Cell manufacturing for clinical applications is a unique form of biologics manufacturing that relies on maintenance of stringent work practices designed to ensure product consistency and prevent contamination by microorganisms or by another patient's cells. More extensive, prolonged laboratory processes involve greater risk of complications and possibly adverse events for the recipient, and so the need for control is correspondingly greater. To minimize the associate risks of cell manufacturing adhering to international quality standards is critical. Current good tissue practice (cGTP) and current good manufacturing practice (cGMP) are examples of general standards that draw a baseline for cell manufacturing facilities. In recent years, stem cell researches have found great public interest in Iran and different cell therapy projects have been started in country. In this review we described the role of our tissue banking experiences in establishing a new cGMP cell manufacturing facility. The authors concluded that, tissue banks and tissue banking experts can broaden their roles from preparing tissue grafts to manufacturing cell and tissue engineered products for translational researches and phase I clinical trials. Also they can collaborate with cell processing laboratories to develop SOPs, implement quality management system, and design cGMP facilities.

DEVELOPMENT OF AN AMPHIBIAN METAMORPHOSIS MODEL FOR DETECTING THYROID AXIS DISRUPTION

EPA Science Inventory

Metamorphosis in Xenopus laevis represents an elaborate process of post-embryonic development which is thyroid hormone (TH) dependent. The development of a functional thyroid axis and the responses of tissues to different TH concentrations are well defined in this species, provid...

Electrospraying of microfluidic encapsulated cells for the fabrication of cell-laden electrospun hybrid tissue constructs.

PubMed

Weidenbacher, L; Abrishamkar, A; Rottmar, M; Guex, A G; Maniura-Weber, K; deMello, A J; Ferguson, S J; Rossi, R M; Fortunato, G

2017-12-01

The fabrication of functional 3D tissues is a major goal in tissue engineering. While electrospinning is a promising technique to manufacture a structure mimicking the extracellular matrix, cell infiltration into electrospun scaffolds remains challenging. The robust and in situ delivery of cells into such biomimetic scaffolds would potentially enable the design of tissue engineered constructs with spatial control over cellular distribution but often solvents employed in the spinning process are problematic due to their high cytotoxicity. Herein, microfluidic cell encapsulation is used to establish a temporary protection vehicle for the in situ delivery of cells for the development of a fibrous, cell-laden hybrid biograft. Therefore a layer-by-layer process is used by alternating fiber electrospinning and cell spraying procedures. Both encapsulation and subsequent electrospraying of capsules has no negative effect on the viability and myogenic differentiation of murine myoblast cells. Propidium iodide positive stained cells were analyzed to quantify the amount of dead cells and the presence of myosin heavy chain positive cells after the processes was shown. Furthermore, encapsulation successfully protects cells from cytotoxic solvents (such as dimethylformamide) during in situ delivery of the cells into electrospun poly(vinylidene fluoride-co-hexafluoropropylene) scaffolds. The resulting cell-populated biografts demonstrate the clear potential of this approach in the creation of viable tissue engineering constructs. Infiltration of cells and their controlled spatial distribution within fibrous electrospun membranes is a challenging task but allows for the development of functional highly organized 3D hybrid tissues. Combining polymer electrospinning and cell electrospraying in a layer-by-layer approach is expected to overcome current limitations of reduced cell infiltration after traditional static seeding. However, organic solvents, used during the electrospinning process, impede often major issues due to their high cytotoxicity. Utilizing microfluidic encapsulation as a mean to embed cells within a protective polymer casing enables the controlled deposition of viable cells without interfering with the cellular phenotype. The presented techniques allow for novel cell manipulation approaches being significant for enhanced 3D tissue engineering based on its versatility in terms of material and cell selection. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Three-Dimensional Printing Articular Cartilage: Recapitulating the Complexity of Native Tissue.

PubMed

Guo, Ting; Lembong, Josephine; Zhang, Lijie Grace; Fisher, John P

2017-06-01

In the past few decades, the field of tissue engineering combined with rapid prototyping (RP) techniques has been successful in creating biological substitutes that mimic tissues. Its applications in regenerative medicine have drawn efforts in research from various scientific fields, diagnostics, and clinical translation to therapies. While some areas of therapeutics are well developed, such as skin replacement, many others such as cartilage repair can still greatly benefit from tissue engineering and RP due to the low success and/or inefficiency of current existing, often surgical treatments. Through fabrication of complex scaffolds and development of advanced materials, RP provides a new avenue for cartilage repair. Computer-aided design and three-dimensional (3D) printing allow the fabrication of modeled cartilage scaffolds for repair and regeneration of damaged cartilage tissues. Specifically, the various processes of 3D printing will be discussed in details, both cellular and acellular techniques, covering the different materials, geometries, and operational printing conditions for the development of tissue-engineered articular cartilage. Finally, we conclude with some insights on future applications and challenges related to this technology, especially using 3D printing techniques to recapitulate the complexity of native structure for advanced cartilage regeneration.

Monitoring the osseointegration process in porous Ti6Al4V implants produced by additive manufacturing: an experimental study in sheep.

PubMed

Kayacan, Mehmet C; Baykal, Yakup B; Karaaslan, Tamer; Özsoy, Koray; Alaca, İlker; Duman, Burhan; Delikanlı, Yunus E

2018-04-01

This study investigated the design and osseointegration process of transitive porous implants that can be used in humans and all trabecular and compact bone structure animals. The aim was to find a way of forming a strong and durable tissue bond on the bone-implant interface. Massive and transitive porous implants were produced on a direct metal laser sintering machine, surgically implanted into the skulls of sheep and kept in place for 12 weeks. At the end of the 12-week period, the Massive and porous implants removed from the sheep were investigated by scanning electron microscopy (SEM) to monitor the osseointegration process. In the literature, each study has selected standard sizes for pore diameter in the structures they use. However, none of these involved transitional porous structures. In this study, as opposed to standard pores, there were spherical or elliptical pores at the micro level, development channels and an inner region. Bone cells developed in the inner region. Transitive pores grown gradually in accordance with the natural structure of the bone were modeled in the inner region for cells to develop. Due to this structure, a strong and durable tissue bond could be formed at the bone-implant interface. Osseointegration processes of Massive vs. porous implants were compared. It was observed that cells were concentrated on the surface of Massive implants. Therefore, osseointegration between implant and bone was less than that of porous implants. In transitive porous implants, as opposed to Massive implants, an outer region was formed in the bone-implant interface that allowed tissue development.

Human natural killer cell development in secondary lymphoid tissues

PubMed Central

Freud, Aharon G.; Yu, Jianhua; Caligiuri, Michael A.

2014-01-01

For nearly a decade it has been appreciated that critical steps in human natural killer (NK) cell development likely occur outside of the bone marrow and potentially necessitate distinct microenvironments within extramedullary tissues. The latter include the liver and gravid uterus as well as secondary lymphoid tissues such as tonsils and lymph nodes. For as yet unknown reasons these tissues are naturally enriched with NK cell developmental intermediates (NKDI) that span a maturation continuum starting from an oligopotent CD34+CD45RA+ hematopoietic precursor cell to a cytolytic mature NK cell. Indeed despite the detection of NKDI within the aforementioned tissues, relatively little is known about how, why, and when these tissues may be most suited to support NK cell maturation and how this process fits in with other components of the human immune system. With the discovery of other innate lymphoid subsets whose immunophenotypes overlap with those of NKDI, there is also need to revisit and potentially re-characterize the basic immunophenotypes of the stages of the human NK cell developmental pathway in vivo. In this review, we provide an overview of human NK cell development in secondary lymphoid tissues and discuss the many questions that remain to be answered in this exciting field. PMID:24661538

Internet-based profiler system as integrative framework to support translational research

PubMed Central

Kim, Robert; Demichelis, Francesca; Tang, Jeffery; Riva, Alberto; Shen, Ronglai; Gibbs, Doug F; Mahavishno, Vasudeva; Chinnaiyan, Arul M; Rubin, Mark A

2005-01-01

Background Translational research requires taking basic science observations and developing them into clinically useful tests and therapeutics. We have developed a process to develop molecular biomarkers for diagnosis and prognosis by integrating tissue microarray (TMA) technology and an internet-database tool, Profiler. TMA technology allows investigators to study hundreds of patient samples on a single glass slide resulting in the conservation of tissue and the reduction in inter-experimental variability. The Profiler system allows investigator to reliably track, store, and evaluate TMA experiments. Here within we describe the process that has evolved through an empirical basis over the past 5 years at two academic institutions. Results The generic design of this system makes it compatible with multiple organ system (e.g., prostate, breast, lung, renal, and hematopoietic system,). Studies and folders are restricted to authorized users as required. Over the past 5 years, investigators at 2 academic institutions have scanned 656 TMA experiments and collected 63,311 digital images of these tissue samples. 68 pathologists from 12 major user groups have accessed the system. Two groups directly link clinical data from over 500 patients for immediate access and the remaining groups choose to maintain clinical and pathology data on separate systems. Profiler currently has 170 K data points such as staining intensity, tumor grade, and nuclear size. Due to the relational database structure, analysis can be easily performed on single or multiple TMA experimental results. The TMA module of Profiler can maintain images acquired from multiple systems. Conclusion We have developed a robust process to develop molecular biomarkers using TMA technology and an internet-based database system to track all steps of this process. This system is extendable to other types of molecular data as separate modules and is freely available to academic institutions for licensing. PMID:16364175

Internet-based Profiler system as integrative framework to support translational research.

PubMed

Kim, Robert; Demichelis, Francesca; Tang, Jeffery; Riva, Alberto; Shen, Ronglai; Gibbs, Doug F; Mahavishno, Vasudeva; Chinnaiyan, Arul M; Rubin, Mark A

2005-12-19

Translational research requires taking basic science observations and developing them into clinically useful tests and therapeutics. We have developed a process to develop molecular biomarkers for diagnosis and prognosis by integrating tissue microarray (TMA) technology and an internet-database tool, Profiler. TMA technology allows investigators to study hundreds of patient samples on a single glass slide resulting in the conservation of tissue and the reduction in inter-experimental variability. The Profiler system allows investigator to reliably track, store, and evaluate TMA experiments. Here within we describe the process that has evolved through an empirical basis over the past 5 years at two academic institutions. The generic design of this system makes it compatible with multiple organ system (e.g., prostate, breast, lung, renal, and hematopoietic system,). Studies and folders are restricted to authorized users as required. Over the past 5 years, investigators at 2 academic institutions have scanned 656 TMA experiments and collected 63,311 digital images of these tissue samples. 68 pathologists from 12 major user groups have accessed the system. Two groups directly link clinical data from over 500 patients for immediate access and the remaining groups choose to maintain clinical and pathology data on separate systems. Profiler currently has 170 K data points such as staining intensity, tumor grade, and nuclear size. Due to the relational database structure, analysis can be easily performed on single or multiple TMA experimental results. The TMA module of Profiler can maintain images acquired from multiple systems. We have developed a robust process to develop molecular biomarkers using TMA technology and an internet-based database system to track all steps of this process. This system is extendable to other types of molecular data as separate modules and is freely available to academic institutions for licensing.

Reflexive Research Ethics in Fetal Tissue Xenotransplantation Research

PubMed Central

Panikkar, Bindu; Smith, Natasha; Brown, Phil

2013-01-01

For biomedical research in which the only involvement of the human subject is the provision of tissue or organ samples, a blanket consent, i.e. consent to use the tissue for anything researchers wish to do, is considered by many to be adequate for legal and IRB requirements. Alternatively, a detailed informed consent provides patients or study participants with more thorough information about the research topic. We document here the beliefs and opinions of the research staff on informed consent and the discussion-based reflexive research ethics process that we employed in our fetal tissue xenotransplantion research on the impact of environmental exposures on fetal development. Reflexive research ethics entails the continued adjustment of research practice according to relational and reflexive understandings of what might be beneficent or harmful. Such reflexivity is not solely an individual endeavor, but rather a collective relationship between all actors in the research process. PMID:23074992

Rapid Engineering of Three-Dimensional, Multicellular Tissues With Polymeric Scaffolds

NASA Technical Reports Server (NTRS)

Gonda, Steve R.; Jordan, Jacqueline; Fraga, Denise N.

2007-01-01

A process has been developed for the rapid tissue engineering of multicellular-tissue-equivalent assemblies by the controlled enzymatic degradation of polymeric beads in a low-fluid-shear bioreactor. In this process, the porous polymeric beads serve as temporary scaffolds to support the assemblies of cells in a tissuelike 3D configuration during the critical initial growth phases of attachment of anchorage-dependent cells, aggregation of the cells, and formation of a 3D extracellular matrix. Once the cells are assembled into a 3D array and enmeshed in a structural supportive 3D extracellular matrix (ECM), the polymeric scaffolds can be degraded in the low-fluid-shear environment of the NASA-designed bioreactor. The natural 3D tissuelike assembly, devoid of any artificial support structure, is maintained in the low-shear bioreactor environment by the newly formed natural cellular/ECM. The elimination of the artificial scaffold allows normal tissue structure and function.

[Fibrous tissue(s): a key for lesion characterization in digestive diseases].

PubMed

Régent, D; Laurent, V; Antunes, L; Debelle, L; Cannard, L; Leclerc, Jc; Beot, S

2002-02-01

Fibrosis is one of the hallmarks of inflammatory and repair processes in pathology. Various exogenous and endogenous stimuli, including tumor development, can induce inflammatory reactions. During the post-equilibrium phase after IV injection of non specific contrast media, CT and/or MR allow the study of these inflammatory answers to tumoral or infectious processes. Delayed enhancement of collagenic fibrous tissue during the late post-equilibrium phase is an essential complementary data in the characterization of many liver lesions: cirrhosis, cholangiocarcinoma, focal nodular hyperplasia, fibrous metastasis. but also for the differential diagnosis of pancreatic diseases (groove pancreatitis vs ductal adenocarcinoma) or of gastro-intestinal diseases (gastric adenocarcinoma vs lymphoma, mechanical complication vs inflammatory bouts of ileal Crohn's disease).

[Quantitative data analysis for live imaging of bone.

PubMed

Seno, Shigeto

Bone tissue is a hard tissue, it was difficult to observe the interior of the bone tissue alive. With the progress of microscopic technology and fluorescent probe technology in recent years, it becomes possible to observe various activities of various cells forming bone society. On the other hand, the quantitative increase in data and the diversification and complexity of the images makes it difficult to perform quantitative analysis by visual inspection. It has been expected to develop a methodology for processing microscopic images and data analysis. In this article, we introduce the research field of bioimage informatics which is the boundary area of biology and information science, and then outline the basic image processing technology for quantitative analysis of live imaging data of bone.

Or mutation leads to photo-oxidative stress responses in cauliflower (Brassica oleracea) seedlings during de-etiolation.

PubMed

Men, Xiao; Dong, Kang

2013-11-01

The Orange (Or) gene is a gene mutation that can increase carotenoid content in plant tissues normally devoid of pigments. It affects plastid division and is involved in the differentiation of proplastids or non-colored plastids into chromoplasts. In this study, the de-etiolation process of the wild type (WT) cauliflower (Brassica oleracea L. var. botrytis) and Or mutant seedlings was investigated. We analyzed pigment content, plastid development, transcript abundance and protein levels of genes involved in the de-etiolation process. The results showed that Or can increase the carotenoid content in green tissues, although not as effectively as in non-green tissues, and this effect might be caused by the changes in biosynthetic pathway genes at both transcriptional and post-transcriptional levels. There was no significant difference in the plastid development process between the two lines. However, the increased content of antheraxanthin and anthocyanin, and higher expression levels of violaxanthin de-epoxidase gene (VDE) suggested a stress situation leading to photoinhibition and enhanced photoprotection in the Or mutant. The up-regulated expression levels of the reactive oxygen species (ROS)-induced genes, ZAT10 for salt tolerance zinc finger protein and ASCORBATE PEROXIDASE2 (APX2), suggested the existence of photo-oxidative stress in the Or mutant. In summary, abovementioned findings provide additional insight into the functions of the Or gene in different tissues and at different developmental stages.

Programmed cell death progressively models the development of anther sporophytic tissues from the tapetum and is triggered in pollen grains during maturation.

PubMed

Varnier, Anne-Lise; Mazeyrat-Gourbeyre, Florence; Sangwan, Rajbir S; Clément, Christophe

2005-11-01

To characterize the spatial and temporal occurrence of programmed cell death (PCD) in Lilium anther tissues, we used both microscopical and molecular markers of apoptosis for developmental stages from meiosis to pollen release. The first hallmarks of PCD include cell condensation and shrinkage of the cytoplasm, separation of chromatin into delineated masses, and DNA fragmentation in the tapetum as early as the premeiosis stage. PCD then extended to other anther sporophytic tissues, leading to anther dehiscence. Although the PCD clearly affected the endothecium and the epidermis, these two cell layers remained alive until anther dehiscence. In pollen, no sign of PCD was found until pollen mitosis I, after what apoptotic features developed progressively in the vegetative cell. In addition, DNA ladders were detected in all sporophytic tissues and cell types throughout pollen development, whereas in the male gametophyte DNA ladders were only detected during pollen maturation. Our data suggest that PCD is a progressive and active process affecting all the anther tissues, first being triggered in the tapetum.

Coordinated Development of Muscles and Tendon-Like Structures: Early Interactions in the Drosophila Leg.

PubMed

Soler, Cedric; Laddada, Lilia; Jagla, Krzysztof

2016-01-01

The formation of the musculoskeletal system is a remarkable example of tissue assembly. In both vertebrates and invertebrates, precise connectivity between muscles and skeleton (or exoskeleton) via tendons or equivalent structures is fundamental for movement and stability of the body. The molecular and cellular processes underpinning muscle formation are well-established and significant advances have been made in understanding tendon development. However, the mechanisms contributing to proper connection between these two tissues have received less attention. Observations of coordinated development of tendons and muscles suggest these tissues may interact during the different steps in their development. There is growing evidence that, depending on animal model and muscle type, these interactions can take place from progenitor induction to the final step of the formation of the musculoskeletal system. Here, we briefly review and compare the mechanisms behind muscle and tendon interaction throughout the development of vertebrates and Drosophila before going on to discuss our recent findings on the coordinated development of muscles and tendon-like structures in Drosophila leg. By altering apodeme formation (the functional Drosophila equivalent of tendons in vertebrates) during the early steps of leg development, we affect the spatial localization of subsequent myoblasts. These findings provide the first evidence of the developmental impact of early interactions between muscle and tendon-like precursors, and confirm the appendicular Drosophila muscle system as a valuable model for studying these processes.

Coordinated Development of Muscles and Tendon-Like Structures: Early Interactions in the Drosophila Leg

PubMed Central

Soler, Cedric; Laddada, Lilia; Jagla, Krzysztof

2016-01-01

The formation of the musculoskeletal system is a remarkable example of tissue assembly. In both vertebrates and invertebrates, precise connectivity between muscles and skeleton (or exoskeleton) via tendons or equivalent structures is fundamental for movement and stability of the body. The molecular and cellular processes underpinning muscle formation are well-established and significant advances have been made in understanding tendon development. However, the mechanisms contributing to proper connection between these two tissues have received less attention. Observations of coordinated development of tendons and muscles suggest these tissues may interact during the different steps in their development. There is growing evidence that, depending on animal model and muscle type, these interactions can take place from progenitor induction to the final step of the formation of the musculoskeletal system. Here, we briefly review and compare the mechanisms behind muscle and tendon interaction throughout the development of vertebrates and Drosophila before going on to discuss our recent findings on the coordinated development of muscles and tendon-like structures in Drosophila leg. By altering apodeme formation (the functional Drosophila equivalent of tendons in vertebrates) during the early steps of leg development, we affect the spatial localization of subsequent myoblasts. These findings provide the first evidence of the developmental impact of early interactions between muscle and tendon-like precursors, and confirm the appendicular Drosophila muscle system as a valuable model for studying these processes. PMID:26869938

UCP1 in adipose tissues: two steps to full browning.

PubMed

Kalinovich, Anastasia V; de Jong, Jasper M A; Cannon, Barbara; Nedergaard, Jan

2017-03-01

The possibility that brown adipose tissue thermogenesis can be recruited in order to combat the development of obesity has led to a high interest in the identification of "browning agents", i.e. agents that increase the amount and activity of UCP1 in brown and brite/beige adipose tissues. However, functional analysis of the browning process yields confusingly different results when the analysis is performed in one of two alternative steps. Thus, in one of the steps, using cold acclimation as a potent model browning agent, we find that if the browning process is followed in mice initially housed at 21 °C (the most common procedure), there is only weak molecular evidence for increases in UCP1 gene expression or UCP1 protein abundance in classical brown adipose tissue; however, in brite/beige adipose depots, there are large increases, apparently associating functional browning with events only in the brite/beige tissues. Contrastingly, in another step, if the process is followed starting with mice initially housed at 30 °C (thermoneutrality for mice, thus similar to normal human conditions), large increases in UCP1 gene expression and UCP1 protein abundance are observed in the classical brown adipose tissue depots; there is then practically no observable UCP1 gene expression in brite/beige tissues. This apparent conundrum can be resolved when it is realized that the classical brown adipose tissue at 21 °C is already essentially fully differentiated and thus expands extensively through proliferation upon further browning induction, rather than by further enhancing cellular differentiation. When the limiting factor for thermogenesis, i.e. the total amount of UCP1 protein per depot, is analyzed, classical brown adipose tissue is by far the predominant site for the browning process, irrespective of which of the two steps is analyzed. There are to date no published data demonstrating that alternative browning agents would selectively promote brite/beige tissues versus classical brown tissue to a higher degree than does cold acclimation. Thus, to restrict investigations to examine adipose tissue depots where only a limited part of the adaptation process occurs (i.e. the brite/beige tissues) and to use initial conditions different from the thermoneutrality normally experienced by adult humans may seriously hamper the identification of therapeutically valid browning agents. The data presented here have therefore important implications for the analysis of the potential of browning agents and the nature of human brown adipose tissue. Copyright © 2017 The Author(s). Published by Elsevier B.V. All rights reserved.

Adipose tissue macrophages in the Development of Obesity-induced Inflammation, Insulin Resistance and Type 2 Diabetes

PubMed Central

Lee, Jongsoon

2014-01-01

It has been increasingly accepted that chronic subacute inflammation plays an important role in the development of insulin resistance and Type 2 Diabetes in animals and humans. Particularly supporting this is that suppression of systemic inflammation in Type 2 Diabetes improves glycemic control; this also points to a new potential therapeutic target for the treatment of Type 2 Diabetes. Recent studies strongly suggest that obesity-induced inflammation is mainly mediated by tissue resident immune cells, with particular attention being focused on adipose tissue macrophages (ATMs). This review delineates the current progress made in understanding obesity-induced inflammation and the roles ATMs play in this process. PMID:23397293

Confocal microscopy with strip mosaicing for rapid imaging over large areas of excised tissue

NASA Astrophysics Data System (ADS)

Abeytunge, Sanjee; Li, Yongbiao; Larson, Bjorg; Peterson, Gary; Seltzer, Emily; Toledo-Crow, Ricardo; Rajadhyaksha, Milind

2013-06-01

Confocal mosaicing microscopy is a developing technology platform for imaging tumor margins directly in freshly excised tissue, without the processing required for conventional pathology. Previously, mosaicing on 12-×-12 mm2 of excised skin tissue from Mohs surgery and detection of basal cell carcinoma margins was demonstrated in 9 min. Last year, we reported the feasibility of a faster approach called "strip mosaicing," which was demonstrated on a 10-×-10 mm2 of tissue in 3 min. Here we describe further advances in instrumentation, software, and speed. A mechanism was also developed to flatten tissue in order to enable consistent and repeatable acquisition of images over large areas. We demonstrate mosaicing on 10-×-10 mm2 of skin tissue with 1-μm lateral resolution in 90 s. A 2.5-×-3.5 cm2 piece of breast tissue was scanned with 0.8-μm lateral resolution in 13 min. Rapid mosaicing of confocal images on large areas of fresh tissue potentially offers a means to perform pathology at the bedside. Imaging of tumor margins with strip mosaicing confocal microscopy may serve as an adjunct to conventional (frozen or fixed) pathology for guiding surgery.

A Computational Model Predicting Disruption of Blood Vessel Development

EPA Science Inventory

Vascular development is a complex process regulated by dynamic biological networks that vary in topology and state across different tissues and developmental stages. Signals regulating de novo blood vessel formation (vasculogenesis) and remodeling (angiogenesis) come from a varie...

Mechanotransductive cascade of Myo-II-dependent mesoderm and endoderm invaginations in embryo gastrulation

PubMed Central

Mitrossilis, Démosthène; Röper, Jens-Christian; Le Roy, Damien; Driquez, Benjamin; Michel, Aude; Ménager, Christine; Shaw, Gorky; Le Denmat, Simon; Ranno, Laurent; Dumas-Bouchiat, Frédéric; Dempsey, Nora M.; Farge, Emmanuel

2017-01-01

Animal development consists of a cascade of tissue differentiation and shape change. Associated mechanical signals regulate tissue differentiation. Here we demonstrate that endogenous mechanical cues also trigger biochemical pathways, generating the active morphogenetic movements shaping animal development through a mechanotransductive cascade of Myo-II medio-apical stabilization. To mimic physiological tissue deformation with a cell scale resolution, liposomes containing magnetic nanoparticles are injected into embryonic epithelia and submitted to time-variable forces generated by a linear array of micrometric soft magnets. Periodic magnetically induced deformations quantitatively phenocopy the soft mechanical endogenous snail-dependent apex pulsations, rescue the medio-apical accumulation of Rok, Myo-II and subsequent mesoderm invagination lacking in sna mutants, in a Fog-dependent mechanotransductive process. Mesoderm invagination then activates Myo-II apical accumulation, in a similar Fog-dependent mechanotransductive process, which in turn initiates endoderm invagination. This reveals the existence of a highly dynamic self-inductive cascade of mesoderm and endoderm invaginations, regulated by mechano-induced medio-apical stabilization of Myo-II. PMID:28112149

Mechanotransductive cascade of Myo-II-dependent mesoderm and endoderm invaginations in embryo gastrulation

NASA Astrophysics Data System (ADS)

Mitrossilis, Démosthène; Röper, Jens-Christian; Le Roy, Damien; Driquez, Benjamin; Michel, Aude; Ménager, Christine; Shaw, Gorky; Le Denmat, Simon; Ranno, Laurent; Dumas-Bouchiat, Frédéric; Dempsey, Nora M.; Farge, Emmanuel

2017-01-01

Animal development consists of a cascade of tissue differentiation and shape change. Associated mechanical signals regulate tissue differentiation. Here we demonstrate that endogenous mechanical cues also trigger biochemical pathways, generating the active morphogenetic movements shaping animal development through a mechanotransductive cascade of Myo-II medio-apical stabilization. To mimic physiological tissue deformation with a cell scale resolution, liposomes containing magnetic nanoparticles are injected into embryonic epithelia and submitted to time-variable forces generated by a linear array of micrometric soft magnets. Periodic magnetically induced deformations quantitatively phenocopy the soft mechanical endogenous snail-dependent apex pulsations, rescue the medio-apical accumulation of Rok, Myo-II and subsequent mesoderm invagination lacking in sna mutants, in a Fog-dependent mechanotransductive process. Mesoderm invagination then activates Myo-II apical accumulation, in a similar Fog-dependent mechanotransductive process, which in turn initiates endoderm invagination. This reveals the existence of a highly dynamic self-inductive cascade of mesoderm and endoderm invaginations, regulated by mechano-induced medio-apical stabilization of Myo-II.

Computational deconvolution of genome wide expression data from Parkinson's and Huntington's disease brain tissues using population-specific expression analysis

PubMed Central

Capurro, Alberto; Bodea, Liviu-Gabriel; Schaefer, Patrick; Luthi-Carter, Ruth; Perreau, Victoria M.

2015-01-01

The characterization of molecular changes in diseased tissues gives insight into pathophysiological mechanisms and is important for therapeutic development. Genome-wide gene expression analysis has proven valuable for identifying biological processes in neurodegenerative diseases using post mortem human brain tissue and numerous datasets are publically available. However, many studies utilize heterogeneous tissue samples consisting of multiple cell types, all of which contribute to global gene expression values, confounding biological interpretation of the data. In particular, changes in numbers of neuronal and glial cells occurring in neurodegeneration confound transcriptomic analyses, particularly in human brain tissues where sample availability and controls are limited. To identify cell specific gene expression changes in neurodegenerative disease, we have applied our recently published computational deconvolution method, population specific expression analysis (PSEA). PSEA estimates cell-type-specific expression values using reference expression measures, which in the case of brain tissue comprises mRNAs with cell-type-specific expression in neurons, astrocytes, oligodendrocytes and microglia. As an exercise in PSEA implementation and hypothesis development regarding neurodegenerative diseases, we applied PSEA to Parkinson's and Huntington's disease (PD, HD) datasets. Genes identified as differentially expressed in substantia nigra pars compacta neurons by PSEA were validated using external laser capture microdissection data. Network analysis and Annotation Clustering (DAVID) identified molecular processes implicated by differential gene expression in specific cell types. The results of these analyses provided new insights into the implementation of PSEA in brain tissues and additional refinement of molecular signatures in human HD and PD. PMID:25620908

Imaging denatured collagen strands in vivo and ex vivo via photo-triggered hybridization of caged collagen mimetic peptides.

PubMed

Li, Yang; Foss, Catherine A; Pomper, Martin G; Yu, S Michael

2014-01-31

Collagen is a major structural component of the extracellular matrix that supports tissue formation and maintenance. Although collagen remodeling is an integral part of normal tissue renewal, excessive amount of remodeling activity is involved in tumors, arthritis, and many other pathological conditions. During collagen remodeling, the triple helical structure of collagen molecules is disrupted by proteases in the extracellular environment. In addition, collagens present in many histological tissue samples are partially denatured by the fixation and preservation processes. Therefore, these denatured collagen strands can serve as effective targets for biological imaging. We previously developed a caged collagen mimetic peptide (CMP) that can be photo-triggered to hybridize with denatured collagen strands by forming triple helical structure, which is unique to collagens. The overall goals of this procedure are i) to image denatured collagen strands resulting from normal remodeling activities in vivo, and ii) to visualize collagens in ex vivo tissue sections using the photo-triggered caged CMPs. To achieve effective hybridization and successful in vivo and ex vivo imaging, fluorescently labeled caged CMPs are either photo-activated immediately before intravenous injection, or are directly activated on tissue sections. Normal skeletal collagen remolding in nude mice and collagens in prefixed mouse cornea tissue sections are imaged in this procedure. The imaging method based on the CMP-collagen hybridization technology presented here could lead to deeper understanding of the tissue remodeling process, as well as allow development of new diagnostics for diseases associated with high collagen remodeling activity.

Increased abundance of ADAM9 transcripts in the blood is associated with tissue damage

PubMed Central

Rinchai, Darawan; Kewcharoenwong, Chidchamai; Kessler, Bianca; Lertmemongkolchai, Ganjana; Chaussabel, Damien

2016-01-01

Background: Members of the ADAM (a disintegrin and metalloprotease domain) family have emerged as critical regulators of cell-cell signaling during development and homeostasis. ADAM9 is consistently overexpressed in various human cancers, and has been shown to play an important role in tumorigenesis. However, little is known about the involvement of ADAM9 during immune-mediated processes. Results: Mining of an extensive compendium of transcriptomic datasets identified important gaps in knowledge regarding the possible role of ADAM9 in immunological homeostasis and inflammation: 1) The abundance of ADAM9 transcripts in the blood was increased in patients with acute infection but, 2) changed very little after in vitro exposure to a wide range of pathogen-associated molecular patterns (PAMPs). 3) Furthermore it was found to increase significantly in subjects as a result of tissue injury or tissue remodeling, in absence of infectious processes. Conclusions: Our findings indicate that ADAM9 may constitute a valuable biomarker for the assessment of tissue damage, especially in clinical situations where other inflammatory markers are confounded by infectious processes. PMID:27990250

The role of the local environment and epigenetics in shaping macrophage identity and their effect on tissue homeostasis.

PubMed

Amit, Ido; Winter, Deborah R; Jung, Steffen

2016-01-01

Macrophages provide a critical systemic network cells of the innate immune system. Emerging data suggest that in addition, they have important tissue-specific functions that range from clearance of surfactant from the lungs to neuronal pruning and establishment of gut homeostasis. The differentiation and tissue-specific activation of macrophages require precise regulation of gene expression, a process governed by epigenetic mechanisms such as DNA methylation, histone modification and chromatin structure. We argue that epigenetic regulation of macrophages is determined by lineage- and tissue-specific transcription factors controlled by the built-in programming of myeloid development in combination with signaling from the tissue environment. Perturbation of epigenetic mechanisms of tissue macrophage identity can affect normal macrophage tissue function and contribute to pathologies ranging from obesity and autoimmunity to neurodegenerative diseases.

The BioDyn facility on ISS: Advancing biomaterial production in microgravity for commercial applications

NASA Astrophysics Data System (ADS)

Myers, Niki; Wessling, Francis; Deuser, Mark; Anderson, C. D.; Lewis, Marian

1999-01-01

The primary goals of the BioDyn program are to foster use of the microgravity environment for commercial production of bio-materials from cells, and to develop services and processes for obtaining these materials through space processing. The scope of products includes commercial bio-molecules such as cytokines, other cell growth regulatory proteins, hormones, monoclonal antibodies and enzymes; transplantable cells or tissues which can be improved by low-G processes, or which cannot be obtained through standard processes in earth gravity; agriculture biotechnology products from plant cells; microencapsulation for diabetes treatment; and factors regulating cellular aging. To facilitate BioDyn's commercial science driven goals, hardware designed for ISS incorporates the flexibility for interchange between the different ISS facilities including the glovebox, various thermal units and centrifuges. By providing a permanent research facility, ISS is the critical space-based platform required by scientists for carrying out the long-term experiments necessary for developing bio-molecules and tissues using several cell culture modalities including suspension and anchorage-dependent cell types.

Monitoring the process of tissue healing of rat skin in vivo after laser irradiation based on optical coherence tomography

NASA Astrophysics Data System (ADS)

He, Youwu; Wu, Shulian; Li, Zhifang; Cai, Shoudong; Li, Hui

2010-11-01

It is imperative to evaluate the tissue wound healing response after laser irradiation so as to develop effective devices for this clinical indication, and evaluate the thermal damage degree to take appropriate treatment. In our research, we prepare 6 white rat (approximately 2 months old, weight :28+/-2g). Each rat was injected intraperitoneally a single dose of 2% pentobarbital sodium. After the rat was anesthetized, the two side of the rats' back were denuded and antisepsised a standardized. An Er:YAG laser (2940nm, 2.5J/cm2, single spot, 4 times) was irradiated on rat skin in vivo, and the skin which before irradiated and the process of renovating scathe that irradiated after Er:YAG laser were observed by an Optical coherence tomography (OCT). The tissue recovery is about a twelve -day period. The results indicate that the scattering coefficient of post- tissue has changed distinctly. The and flexibility fiber is the chief component of rat dermis and the collagen is the main scattering material. The normal tissue has a large scattering coefficient, after laser irradiated, the collagen became concreting and putrescence and caused the structure change. It became more uniform density distribution, which results in a reduced scattering coefficient. In a word, OCT can noninvasively monitor changes in collagen structure and the recover process in thermal damage through monitor the tissue scattering coefficient.

Development and characterization of decellularized human nasoseptal cartilage matrix for use in tissue engineering.

PubMed

Graham, M Elise; Gratzer, Paul F; Bezuhly, Michael; Hong, Paul

2016-10-01

Reconstruction of cartilage defects in the head and neck can require harvesting of autologous cartilage grafts, which can be associated with donor site morbidity. To overcome this limitation, tissue-engineering approaches may be used to generate cartilage grafts. The objective of this study was to decellularize and characterize human nasoseptal cartilage with the aim of generating a biological scaffold for cartilage tissue engineering. Laboratory study using nasoseptal cartilage. Remnant human nasoseptal cartilage specimens were collected and subjected to a novel decellularization treatment. The decellularization process involved several cycles of enzymatic detergent treatments. For characterization, decellularized and fresh (control) specimens underwent histological, biochemical, and mechanical analyses. Scanning electron microscopy and biocompatibility assay were also performed. The decellularization process had minimal effect on glycosaminoglycan content of the cartilage extracellular matrix. Deoxyribonucleic acid (DNA) analysis revealed the near-complete removal of genomic DNA from decellularized tissues. The effectiveness of the decellularization process was also confirmed on histological and scanning electron microscopic analyses. Mechanical testing results showed that the structural integrity of the decellularized tissue was maintained, and biocompatibility was confirmed. Overall, the current decellularization treatment resulted in significant reduction of genetic/cellular material with preservation of the underlying extracellular matrix structure. This decellularized material may serve as a potential scaffold for cartilage tissue engineering. N/A. Laryngoscope, 126:2226-2231, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

Use of fibroblast growth factor 2 for expansion of chondrocytes and tissue engineering

NASA Technical Reports Server (NTRS)

Vunjak-Novakovic, Gordana (Inventor); Martin, Ivan (Inventor); Freed, Lisa E. (Inventor); Langer, Robert (Inventor)

2003-01-01

The present invention provides an improved method for expanding cells for use in tissue engineering. In particular the method provides specific biochemical factors to supplement cell culture medium during the expansion process in order to reproduce events occurring during embryonic development with the goal of regenerating tissue equivalents that resemble natural tissues both structurally and functionally. These specific biochemical factors improve proliferation of the cells and are capable of de-differentiation mature cells isolated from tissue so that the differentiation potential of the cells is preserved. The bioactive molecules also maintain the responsiveness of the cells to other bioactive molecules. Specifically, the invention provides methods for expanding chondrocytes in the presence of fibroblast growth factor 2 for use in regeneration of cartilage tissue.

Studying cytokinesis in Drosophila epithelial tissues.

PubMed

Pinheiro, D; Bellaïche, Y

2017-01-01

Epithelial tissue cohesiveness is ensured through cell-cell junctions that maintain both adhesion and mechanical coupling between neighboring cells. During development, epithelial tissues undergo intensive cell proliferation. Cell division, and particularly cytokinesis, is coupled to the formation of new adhesive contacts, thereby preserving tissue integrity and propagating cell polarity. Remarkably, the geometry of the new interfaces is determined by the combined action of the dividing cell and its neighbors. To further understand the interplay between the dividing cell and its neighbors, as well as the role of cell division for tissue morphogenesis, it is important to analyze cytokinesis in vivo. Here we present methods to perform live imaging of cell division in Drosophila epithelial tissues and discuss some aspects of image processing and analysis. Copyright © 2017 Elsevier Inc. All rights reserved.

Biotechnology in Food Production and Processing

NASA Astrophysics Data System (ADS)

Knorr, Dietrich; Sinskey, Anthony J.

1985-09-01

The food processing industry is the oldest and largest industry using biotechnological processes. Further development of food products and processes based on biotechnology depends upon the improvement of existing processes, such as fermentation, immobilized biocatalyst technology, and production of additives and processing aids, as well as the development of new opportunities for food biotechnology. Improvements are needed in the characterization, safety, and quality control of food materials, in processing methods, in waste conversion and utilization processes, and in currently used food microorganism and tissue culture systems. Also needed are fundamental studies of the structure-function relationship of food materials and of the cell physiology and biochemistry of raw materials.

Organogenesis in plants: initiation and elaboration of leaves

USDA-ARS?s Scientific Manuscript database

Plant organs initiate from meristems and grow into diverse forms. After initiation, organs enter a morphological phase where they develop their shape, followed by differentiation into mature tissue. Investigations into these processes have revealed numerous factors necessary for proper development, ...

Nutritional programming of reproductive development in heifers

USDA-ARS?s Scientific Manuscript database

Developmental programming is the biological process by which environmental factors influence the development of the organs and tissues in the body. There are two areas of developmental programming being investigated with applicability to beef production systems to improve performance of replacement...

Roles of the canonical myomiRs miR-1, -133 and -206 in cell development and disease

PubMed Central

Mitchelson, Keith Richard; Qin, Wen-Yan

2015-01-01

MicroRNAs are small non-coding RNAs that participate in different biological processes, providing subtle combinational regulation of cellular pathways, often by regulating components of signalling pathways. Aberrant expression of miRNAs is an important factor in the development and progression of disease. The canonical myomiRs (miR-1, -133 and -206) are central to the development and health of mammalian skeletal and cardiac muscles, but new findings show they have regulatory roles in the development of other mammalian non-muscle tissues, including nerve, brain structures, adipose and some specialised immunological cells. Moreover, the deregulation of myomiR expression is associated with a variety of different cancers, where typically they have tumor suppressor functions, although examples of an oncogenic role illustrate their diverse function in different cell environments. This review examines the involvement of the related myomiRs at the crossroads between cell development/tissue regeneration/tissue inflammation responses, and cancer development. PMID:26322174

Biomechanics and mechanobiology in functional tissue engineering.

PubMed

Guilak, Farshid; Butler, David L; Goldstein, Steven A; Baaijens, Frank P T

2014-06-27

The field of tissue engineering continues to expand and mature, and several products are now in clinical use, with numerous other preclinical and clinical studies underway. However, specific challenges still remain in the repair or regeneration of tissues that serve a predominantly biomechanical function. Furthermore, it is now clear that mechanobiological interactions between cells and scaffolds can critically influence cell behavior, even in tissues and organs that do not serve an overt biomechanical role. Over the past decade, the field of "functional tissue engineering" has grown as a subfield of tissue engineering to address the challenges and questions on the role of biomechanics and mechanobiology in tissue engineering. Originally posed as a set of principles and guidelines for engineering of load-bearing tissues, functional tissue engineering has grown to encompass several related areas that have proven to have important implications for tissue repair and regeneration. These topics include measurement and modeling of the in vivo biomechanical environment; quantitative analysis of the mechanical properties of native tissues, scaffolds, and repair tissues; development of rationale criteria for the design and assessment of engineered tissues; investigation of the effects biomechanical factors on native and repair tissues, in vivo and in vitro; and development and application of computational models of tissue growth and remodeling. Here we further expand this paradigm and provide examples of the numerous advances in the field over the past decade. Consideration of these principles in the design process will hopefully improve the safety, efficacy, and overall success of engineered tissue replacements. Copyright © 2014 Elsevier Ltd. All rights reserved.

The role of hypothalamic inflammation, the hypothalamic-pituitary-adrenal axis and serotonin in the cancer anorexia-cachexia syndrome.

PubMed

van Norren, Klaske; Dwarkasing, Jvalini T; Witkamp, Renger F

2017-09-01

In cancer patients, the development of cachexia (muscle wasting) is frequently aggravated by anorexia (loss of appetite). Their concurrence is often referred to as anorexia-cachexia syndrome. This review focusses on the recent evidence underlining hypothalamic inflammation as key driver of these processes. Special attention is given to the involvement of hypothalamic serotonin. The anorexia-cachexia syndrome is directly associated with higher mortality in cancer patients. Recent reports confirm its severe impact on the quality of life of patients and their families.Hypothalamic inflammation has been shown to contribute to muscle and adipose tissue loss in cancer via central hypothalamic interleukine (IL)1β-induced activation of the hypothalamic-pituitary-adrenal axis. The resulting release of glucocorticoids directly stimulates catabolic processes in these tissues via activation of the ubiquitin-proteosome pathway. Next to this, hypothalamic inflammation has been shown to reduce food intake in cancer by triggering changes in orexigenic and anorexigenic responses via upregulation of serotonin availability and stimulation of its signalling pathways in hypothalamic tissues. This combination of reduced food intake and stimulation of tissue catabolism represents a dual mechanism by which hypothalamic inflammation contributes to the development and maintenance of anorexia and cachexia in cancer. Hypothalamic inflammation is a driving force in the development of the anorexia-cachexia syndrome via hypothalamic-pituitary-adrenal axis and serotonin pathway activation.

Biogenesis of protein bodies during legumin accumulation in developing olive (Olea europaea L.) seed.

PubMed

Jimenez-Lopez, Jose C; Zienkiewicz, Agnieszka; Zienkiewicz, Krzysztof; Alché, Juan D; Rodríguez-García, Maria I

2016-03-01

Much of our current knowledge about seed development and differentiation regarding reserves synthesis and accumulation come from monocot (cereals) plants. Studies in dicotyledonous seeds differentiation are limited to a few species and in oleaginous species are even scarcer despite their agronomic and economic importance. We examined the changes accompanying the differentiation of olive endosperm and cotyledon with a focus on protein bodies (PBs) biogenesis during legumin protein synthesis and accumulation, with the aim of getting insights and a better understanding of the PBs' formation process. Cotyledon and endosperm undergo differentiation during seed development, where an asynchronous time-course of protein synthesis, accumulation, and differential PB formation patterns was found in both tissues. At the end of seed maturation, a broad population of PBs, particularly in cotyledon cells, was distinguishable in terms of number per cell and morphometric and cytochemical features. Olive seed development is a tissue-dependent process characterized by differential rates of legumin accumulation and PB formation in the main tissues integrating seed. One of the main features of the impressive differentiation process is the specific formation of a broad group of PBs, particularly in cotyledon cells, which might depend on selective accumulation and packaging of proteins and specific polypeptides into PBs. The nature and availability of the major components detected in the PBs of olive seed are key parameters in order to consider the potential use of this material as a suitable source of carbon and nitrogen for animal or even human use.

Impact of heat stress during seed development on soybean seed metabolome

USDA-ARS?s Scientific Manuscript database

Seed development is a temperature-sensitive process that is much more vulnerable than vegetative tissues to abiotic stresses. Climate change is expected to increase the incidence and severity of summer heatwaves, and the impact of heat stress on seed development is expected to become more widespread...

Use of focused ultrasonication in activity-based profiling of deubiquitinating enzymes in tissue.

PubMed

Nanduri, Bindu; Shack, Leslie A; Rai, Aswathy N; Epperson, William B; Baumgartner, Wes; Schmidt, Ty B; Edelmann, Mariola J

2016-12-15

To develop a reproducible tissue lysis method that retains enzyme function for activity-based protein profiling, we compared four different methods to obtain protein extracts from bovine lung tissue: focused ultrasonication, standard sonication, mortar & pestle method, and homogenization combined with standard sonication. Focused ultrasonication and mortar & pestle methods were sufficiently effective for activity-based profiling of deubiquitinases in tissue, and focused ultrasonication also had the fastest processing time. We used focused-ultrasonicator for subsequent activity-based proteomic analysis of deubiquitinases to test the compatibility of this method in sample preparation for activity-based chemical proteomics. Copyright © 2016 Elsevier Inc. All rights reserved.

Ultrasonically Assisted Cutting of Bio-tissues in Microtomy

NASA Astrophysics Data System (ADS)

Wang, Dong; Roy, Anish; Silberschmidt, Vadim V.

Modern-day histology of bio-tissues for supporting stratified medicine diagnoses requires high-precision cutting to ensure high quality extremely thin specimens used in analysis. Additionally, the cutting quality is significantly affected by a wide variety of soft and hard tissues in the samples. This paper deals with development of a next generation of microtome employing introduction of controlled ultrasonic vibration to realise a hybrid cutting process of bio-tissues. The study is based on a combination of advanced experimental and numerical (finite-element) studies of multi-body dynamics of a cutting system. The quality of cut samples produced with the prototype is compared with the state-of-the-art.

Determination of notochord cells of Xenopus laevis.

PubMed

Zeng, M B

1993-12-01

In amphibians, numerous works of influences of the notochord on neighbouring tissues have been accumulated. However, on the contrary, scarcely any work is known about how the notochord is influenced by its neighbouring tissues and how it is determined. By using the experimental method of explantation and culturing in vitro, how the notochord is determined in the early development and whether the neighbouring tissues exert influences on it have been investigated. The results showed that the determination of notochord is a progressive process and the presumptive notochord of Xenopus appears to be a very good material to study influences of neighbouring tissues on the determination of the notochord.

Application of laser scanning confocal microscopy in the soft tissue exquisite structure for 3D scan

PubMed Central

Zhang, Zhaoqiang; Ibrahim, Mohamed; Fu, Yang; Wu, Xujia; Ren, Fei; Chen, Lei

2018-01-01

Three-dimensional (3D) printing is a new developing technology for printing individualized materials swiftly and precisely in the field of biological medicine (especially tissue-engineered materials). Prior to printing, it is necessary to scan the structure of the natural biological tissue, then construct the 3D printing digital model through optimizing the scanned data. By searching the literatures, magazines at home and abroad, this article reviewed the current status, main processes and matters needing attention of confocal laser scanning microscope (LSCM) in the application of soft tissue fine structure 3D scanning, empathizing the significance of LSCM in this field. PMID:29755838

Microfluidic devices for stem-cell cultivation, differentiation and toxicity testing

NASA Astrophysics Data System (ADS)

Becker, Holger; Hansen-Hagge, Thomas; Kurtz, Andreas; Mrowka, Ralf; Wölfl, Stefan; Gärtner, Claudia

2017-02-01

The development of new drugs is time-consuming, extremely expensive and often promising drug candidates fail in late stages of the development process due to the lack of suitable tools to either predict toxicological effects or to test drug candidates in physiologically relevant environments prior to clinical tests. We therefore try to develop diagnostic multiorgan microfluidic chips based on patient specific induced pluripotent stem cell (iPS) technology to explore liver dependent toxic effects of drugs on individual human tissues such as liver or kidney cells. Based initially on standardized microfluidic modules for cell culture, we have developed integrated microfluidic devices which contain different chambers for cell/tissue cultivation. The devices are manufactured using injection molding of thermoplastic polymers such as polystyrene or cyclo-olefin polymer. In the project, suitable surface modification methods of the used materials had to be explored. We have been able to successfully demonstrate the seeding, cultivation and further differentiation of modified iPS, as shown by the use of differentiation markers, thus providing a suitable platform for toxicity testing and potential tissue-tissue interactions.

Tissue Specific Localization of Pectin–Ca2+ Cross-Linkages and Pectin Methyl-Esterification during Fruit Ripening in Tomato (Solanum lycopersicum)

PubMed Central

Hyodo, Hiromi; Terao, Azusa; Furukawa, Jun; Sakamoto, Naoya; Yurimoto, Hisayoshi; Satoh, Shinobu; Iwai, Hiroaki

2013-01-01

Fruit ripening is one of the developmental processes accompanying seed development. The tomato is a well-known model for studying fruit ripening and development, and the disassembly of primary cell walls and the middle lamella, such as through pectin de-methylesterified by pectin methylesterase (PE) and depolymerization by polygalacturonase (PG), is generally accepted to be one of the major changes that occur during ripening. Although many reports of the changes in pectin during tomato fruit ripening are focused on the relation to softening of the pericarp or the Blossom-end rot by calcium (Ca2+) deficiency disorder, the changes in pectin structure and localization in each tissues during tomato fruit ripening is not well known. In this study, to elucidate the tissue-specific role of pectin during fruit development and ripening, we examined gene expression, the enzymatic activities involved in pectin synthesis and depolymerisation in fruit using biochemical and immunohistochemical analyses, and uronic acids and calcium (Ca)-bound pectin were determined by secondary ion-microprobe mass spectrometry. These results show that changes in pectin properties during fruit development and ripening have tissue-specific patterns. In particular, differential control of pectin methyl-esterification occurs in each tissue. Variations in the cell walls of the pericarp are quite different from that of locular tissues. The Ca-binding pectin and hairy pectin in skin cell layers are important for intercellular and tissue–tissue adhesion. Maintenance of the globular form and softening of tomato fruit may be regulated by the arrangement of pectin structures in each tissue. PMID:24236073

Invited review: Pre- and postnatal adipose tissue development in farm animals: from stem cells to adipocyte physiology.

PubMed

Louveau, I; Perruchot, M-H; Bonnet, M; Gondret, F

2016-11-01

Both white and brown adipose tissues are recognized to be differently involved in energy metabolism and are also able to secrete a variety of factors called adipokines that are involved in a wide range of physiological and metabolic functions. Brown adipose tissue is predominant around birth, except in pigs. Irrespective of species, white adipose tissue has a large capacity to expand postnatally and is able to adapt to a variety of factors. The aim of this review is to update the cellular and molecular mechanisms associated with pre- and postnatal adipose tissue development with a special focus on pigs and ruminants. In contrast to other tissues, the embryonic origin of adipose cells remains the subject of debate. Adipose cells arise from the recruitment of specific multipotent stem cells/progenitors named adipose tissue-derived stromal cells. Recent studies have highlighted the existence of a variety of those cells being able to differentiate into white, brown or brown-like/beige adipocytes. After commitment to the adipocyte lineage, progenitors undergo large changes in the expression of many genes involved in cell cycle arrest, lipid accumulation and secretory functions. Early nutrition can affect these processes during fetal and perinatal periods and can also influence or pre-determinate later growth of adipose tissue. How these changes may be related to adipose tissue functional maturity around birth and can influence newborn survival is discussed. Altogether, a better knowledge of fetal and postnatal adipose tissue development is important for various aspects of animal production, including neonatal survival, postnatal growth efficiency and health.

Printing of Three-Dimensional Tissue Analogs for Regenerative Medicine

PubMed Central

Lee, Vivian K.; Dai, Guohao

2016-01-01

3-D cell printing, which can accurately deposit cells, biomaterial scaffolds and growth factors in precisely defined spatial patterns to form biomimetic tissue structures, has emerged as a powerful enabling technology to create live tissue and organ structures for drug discovery and tissue engineering applications. Unlike traditional 3-D printing that uses metals, plastics and polymers as the printing materials, cell printing has to be compatible with living cells and biological matrix. It is also required that the printing process preserves the biological functions of the cells and extracellular matrix, and to mimic the cell-matrix architectures and mechanical properties of the native tissues. Therefore, there are significant challenges in order to translate the technologies of traditional 3-D printing to cell printing, and ultimately achieve functional outcomes in the printed tissues. So it is essential to develop new technologies specially designed for cell printing and in-depth basic research in the bioprinted tissues, such as developing novel biomaterials specifically for cell printing applications, understanding the complex cell-matrix remodeling for the desired mechanical properties and functional outcomes, establishing proper vascular perfusion in bioprinted tissues, etc. In recent years, many exciting research progresses have been made in the 3-D cell printing technology and its application in engineering live tissue constructs. This review paper summarized the current development in 3-D cell printing technologies; focus on the outcomes of the live printed tissues and their potential applications in drug discovery and regenerative medicine. Current challenges and limitations are highlighted, and future directions of 3-D cell printing technology are also discussed. PMID:27066784

Lineage-specific splicing of a brain-enriched alternative exon promotes glioblastoma progression

PubMed Central

Ferrarese, Roberto; Harsh, Griffith R.; Yadav, Ajay K.; Bug, Eva; Maticzka, Daniel; Reichardt, Wilfried; Dombrowski, Stephen M.; Miller, Tyler E.; Masilamani, Anie P.; Dai, Fangping; Kim, Hyunsoo; Hadler, Michael; Scholtens, Denise M.; Yu, Irene L.Y.; Beck, Jürgen; Srinivasasainagendra, Vinodh; Costa, Fabrizio; Baxan, Nicoleta; Pfeifer, Dietmar; von Elverfeldt, Dominik; Backofen, Rolf; Weyerbrock, Astrid; Duarte, Christine W.; He, Xiaolin; Prinz, Marco; Chandler, James P.; Vogel, Hannes; Chakravarti, Arnab; Rich, Jeremy N.; Carro, Maria S.; Bredel, Markus

2014-01-01

Tissue-specific alternative splicing is critical for the emergence of tissue identity during development, yet the role of this process in malignant transformation is undefined. Tissue-specific splicing involves evolutionarily conserved, alternative exons that represent only a minority of the total alternative exons identified. Many of these conserved exons have functional features that influence signaling pathways to profound biological effect. Here, we determined that lineage-specific splicing of a brain-enriched cassette exon in the membrane-binding tumor suppressor annexin A7 (ANXA7) diminishes endosomal targeting of the EGFR oncoprotein, consequently enhancing EGFR signaling during brain tumor progression. ANXA7 exon splicing was mediated by the ribonucleoprotein PTBP1, which is normally repressed during neuronal development. PTBP1 was highly expressed in glioblastomas due to loss of a brain-enriched microRNA (miR-124) and to PTBP1 amplification. The alternative ANXA7 splicing trait was present in precursor cells, suggesting that glioblastoma cells inherit the trait from a potential tumor-initiating ancestor and that these cells exploit this trait through accumulation of mutations that enhance EGFR signaling. Our data illustrate that lineage-specific splicing of a tissue-regulated alternative exon in a constituent of an oncogenic pathway eliminates tumor suppressor functions and promotes glioblastoma progression. This paradigm may offer a general model as to how tissue-specific regulatory mechanisms can reprogram normal developmental processes into oncogenic ones. PMID:24865424

Developing a toolbox for analysis of warrior wound biopsies: vibrational spectroscopy

NASA Astrophysics Data System (ADS)

Crane, Nicole J.; O'Brien, Frederick P.; Forsberg, Jonathan A.; Potter, Benjamin K.; Elster, Eric A.

2011-03-01

The management of modern traumatic war wounds remains a significant challenge for clinicians. This is a reflection of the extensive osseous and soft-tissue damage caused by blasts and high-energy projectiles. The ensuing inflammatory response ultimately dictates the pace of wound healing and tissue regeneration. Consequently, the eventual timing of wound closure or definitive coverage is often subjectively based. Some wounds require an extended period of time to close or fail to remain closed, despite the use and application of novel wound-specific treatment modalities. Aside from impaired wound healing, additional wound complications include wound infection, biofilm formation, and heterotopic ossification (the pathological mineralization of soft tissues). An understanding of the molecular environment of acute wounds throughout the debridement process can provide valuable insight into the mechanisms associated with the eventual wound outcome. The analysis of Raman spectra of ex vivo wound biopsy tissue obtained from serial traumatic wound debridements reveals a decreased 1665 cm-1/1445 cm-1 band area ratio in impaired healing wounds, indicative of an impaired remodeling process, in addition to a decreased 1240 cm-1/1270cm-1. The examination of debrided tissue exhibits mineralization during the early development of heterotopic ossification. Finally, preliminary results suggest that Fourier transform infrared (FT-IR) images of wound effluent may be able to provide early microbiological information about the wound.

Additive manufacturing techniques for the production of tissue engineering constructs.

PubMed

Mota, Carlos; Puppi, Dario; Chiellini, Federica; Chiellini, Emo

2015-03-01

'Additive manufacturing' (AM) refers to a class of manufacturing processes based on the building of a solid object from three-dimensional (3D) model data by joining materials, usually layer upon layer. Among the vast array of techniques developed for the production of tissue-engineering (TE) scaffolds, AM techniques are gaining great interest for their suitability in achieving complex shapes and microstructures with a high degree of automation, good accuracy and reproducibility. In addition, the possibility of rapidly producing tissue-engineered constructs meeting patient's specific requirements, in terms of tissue defect size and geometry as well as autologous biological features, makes them a powerful way of enhancing clinical routine procedures. This paper gives an extensive overview of different AM techniques classes (i.e. stereolithography, selective laser sintering, 3D printing, melt-extrusion-based techniques, solution/slurry extrusion-based techniques, and tissue and organ printing) employed for the development of tissue-engineered constructs made of different materials (i.e. polymeric, ceramic and composite, alone or in combination with bioactive agents), by highlighting their principles and technological solutions. Copyright © 2012 John Wiley & Sons, Ltd.

The AP2/ERF Transcription Factor DRNL Modulates Gynoecium Development and Affects Its Response to Cytokinin.

PubMed

Durán-Medina, Yolanda; Serwatowska, Joanna; Reyes-Olalde, J Irepan; de Folter, Stefan; Marsch-Martínez, Nayelli

2017-01-01

The gynoecium is the female reproductive system in flowering plants. It is a complex structure formed by different tissues, some that are essential for reproduction and others that facilitate the fertilization process and nurture and protect the developing seeds. The coordinated development of these different tissues during the formation of the gynoecium is important for reproductive success. Both hormones and genetic regulators guide the development of the different tissues. Auxin and cytokinin in particular have been found to play important roles in this process. On the other hand, the AP2/ERF2 transcription factor BOL/DRNL/ESR2/SOB is expressed at very early stages of aerial organ formation and has been proposed to be a marker for organ founder cells. In this work, we found that this gene is also expressed at later stages during gynoecium development, particularly at the lateral regions (the region related to the valves of the ovary). The loss of DRNL function affects gynoecium development. Some of the mutant phenotypes present similarities to those observed in plants treated with exogenous cytokinins, and AHP6 has been previously proposed to be a target of DRNL. Therefore, we explored the response of drnl-2 developing gynoecia to cytokinins, and found that the loss of DRNL function affects the response of the gynoecium to exogenously applied cytokinins in a developmental-stage-dependent manner. In summary, this gene participates during gynoecium development, possibly through the dynamic modulation of cytokinin homeostasis and response.

The AP2/ERF Transcription Factor DRNL Modulates Gynoecium Development and Affects Its Response to Cytokinin

PubMed Central

Durán-Medina, Yolanda; Serwatowska, Joanna; Reyes-Olalde, J. Irepan; de Folter, Stefan; Marsch-Martínez, Nayelli

2017-01-01

The gynoecium is the female reproductive system in flowering plants. It is a complex structure formed by different tissues, some that are essential for reproduction and others that facilitate the fertilization process and nurture and protect the developing seeds. The coordinated development of these different tissues during the formation of the gynoecium is important for reproductive success. Both hormones and genetic regulators guide the development of the different tissues. Auxin and cytokinin in particular have been found to play important roles in this process. On the other hand, the AP2/ERF2 transcription factor BOL/DRNL/ESR2/SOB is expressed at very early stages of aerial organ formation and has been proposed to be a marker for organ founder cells. In this work, we found that this gene is also expressed at later stages during gynoecium development, particularly at the lateral regions (the region related to the valves of the ovary). The loss of DRNL function affects gynoecium development. Some of the mutant phenotypes present similarities to those observed in plants treated with exogenous cytokinins, and AHP6 has been previously proposed to be a target of DRNL. Therefore, we explored the response of drnl-2 developing gynoecia to cytokinins, and found that the loss of DRNL function affects the response of the gynoecium to exogenously applied cytokinins in a developmental-stage-dependent manner. In summary, this gene participates during gynoecium development, possibly through the dynamic modulation of cytokinin homeostasis and response. PMID:29123539

An ancient defense system eliminates unfit cells from developing tissues during cell competition

PubMed Central

Meyer, S. N.; Amoyel, M.; Bergantiños, C.; de la Cova, C.; Schertel, C.; Basler, K.; Johnston, L. A.

2016-01-01

Developing tissues that contain mutant or compromised cells present risks to animal health. Accordingly, the appearance of a population of suboptimal cells in a tissue elicits cellular interactions that prevent their contribution to the adult. Here we report that this quality control process, cell competition, uses specific components of the evolutionarily ancient and conserved innate immune system to eliminate Drosophila cells perceived as unfit. We find that Toll-related receptors (TRRs) and the cytokine Spätzle (Spz) lead to NFκB-dependent apoptosis. Diverse “loser” cells require different TRRs and NFκB factors and activate distinct pro-death genes, implying that the particular response is stipulated by the competitive context. Our findings demonstrate a functional repurposing of components of TRRs and NFκB signaling modules in the surveillance of cell fitness during development. PMID:25477468

Formation of Structured Water and Gas Hydrate by the Use of Xenon Gas in Vegetable Tissue

NASA Astrophysics Data System (ADS)

Ando, Hiroko; Suzuki, Toru; Kawagoe, Yoshinori; Makino, Yoshio; Oshita, Seiichi

Freezing is a valuable technique for food preservation. However, vegetables are known to be softening remarkably after freezing and thawing process. It is expected to find alternative technique instead of freezing. Recently, the application of structured water and/or gas hydrate had been attempted to prolong the preservation of vegetable. In this study, the formation process of structure water and/or gas hydrate in pure water and carrot tissue was investigated by using NMR relaxation times, T1 and T2, of which applying condition was up to 0.4MPa and 0.8MPa at 5oC. Under the pressure of 0.4MPa, no gas hydrate was appeared, however, at 0.8MPa, formation of gas hydrate was recognized in both water and carrot tissue. Once the gas hydrate formation process in carrot tissue started, T1 and T2 increased remarkably. After that, as the gas hydrate developed, then T1 and T2 turned to decrease. Since this phenomenon was not observed in pure water, it is suggested that behavior of NMR relaxation time just after the formation of gas hydrate in carrot tissue may be peculiar to compartment system such as inter and intracellular spaces.

Friction forces position the neural anlage

PubMed Central

Smutny, Michael; Ákos, Zsuzsa; Grigolon, Silvia; Shamipour, Shayan; Ruprecht, Verena; Čapek, Daniel; Behrndt, Martin; Papusheva, Ekaterina; Tada, Masazumi; Hof, Björn; Vicsek, Tamás; Salbreux, Guillaume; Heisenberg, Carl-Philipp

2017-01-01

During embryonic development, mechanical forces are essential for cellular rearrangements driving tissue morphogenesis. Here, we show that in the early zebrafish embryo, friction forces are generated at the interface between anterior axial mesoderm (prechordal plate, ppl) progenitors migrating towards the animal pole and neurectoderm progenitors moving in the opposite direction towards the vegetal pole of the embryo. These friction forces lead to global rearrangement of cells within the neurectoderm and determine the position of the neural anlage. Using a combination of experiments and simulations, we show that this process depends on hydrodynamic coupling between neurectoderm and ppl as a result of E-cadherin-mediated adhesion between those tissues. Our data thus establish the emergence of friction forces at the interface between moving tissues as a critical force-generating process shaping the embryo. PMID:28346437

Friction forces position the neural anlage.

PubMed

Smutny, Michael; Ákos, Zsuzsa; Grigolon, Silvia; Shamipour, Shayan; Ruprecht, Verena; Čapek, Daniel; Behrndt, Martin; Papusheva, Ekaterina; Tada, Masazumi; Hof, Björn; Vicsek, Tamás; Salbreux, Guillaume; Heisenberg, Carl-Philipp

2017-04-01

During embryonic development, mechanical forces are essential for cellular rearrangements driving tissue morphogenesis. Here, we show that in the early zebrafish embryo, friction forces are generated at the interface between anterior axial mesoderm (prechordal plate, ppl) progenitors migrating towards the animal pole and neurectoderm progenitors moving in the opposite direction towards the vegetal pole of the embryo. These friction forces lead to global rearrangement of cells within the neurectoderm and determine the position of the neural anlage. Using a combination of experiments and simulations, we show that this process depends on hydrodynamic coupling between neurectoderm and ppl as a result of E-cadherin-mediated adhesion between those tissues. Our data thus establish the emergence of friction forces at the interface between moving tissues as a critical force-generating process shaping the embryo.

21 CFR 876.5885 - Tissue culture media for human ex vivo tissue and cell culture processing applications.

Code of Federal Regulations, 2010 CFR

2010-04-01

... cell culture processing applications. 876.5885 Section 876.5885 Food and Drugs FOOD AND DRUG... DEVICES Therapeutic Devices § 876.5885 Tissue culture media for human ex vivo tissue and cell culture processing applications. (a) Identification. Tissue culture media for human ex vivo tissue and cell culture...

Scaffold Free Bio-orthogonal Assembly of 3-Dimensional Cardiac Tissue via Cell Surface Engineering

NASA Astrophysics Data System (ADS)

Rogozhnikov, Dmitry; O'Brien, Paul J.; Elahipanah, Sina; Yousaf, Muhammad N.

2016-12-01

There has been tremendous interest in constructing in vitro cardiac tissue for a range of fundamental studies of cardiac development and disease and as a commercial system to evaluate therapeutic drug discovery prioritization and toxicity. Although there has been progress towards studying 2-dimensional cardiac function in vitro, there remain challenging obstacles to generate rapid and efficient scaffold-free 3-dimensional multiple cell type co-culture cardiac tissue models. Herein, we develop a programmed rapid self-assembly strategy to induce specific and stable cell-cell contacts among multiple cell types found in heart tissue to generate 3D tissues through cell-surface engineering based on liposome delivery and fusion to display bio-orthogonal functional groups from cell membranes. We generate, for the first time, a scaffold free and stable self assembled 3 cell line co-culture 3D cardiac tissue model by assembling cardiomyocytes, endothelial cells and cardiac fibroblast cells via a rapid inter-cell click ligation process. We compare and analyze the function of the 3D cardiac tissue chips with 2D co-culture monolayers by assessing cardiac specific markers, electromechanical cell coupling, beating rates and evaluating drug toxicity.

From stem to roots: Tissue engineering in endodontics

PubMed Central

Kala, M.; Banthia, Priyank; Banthia, Ruchi

2012-01-01

The vitality of dentin-pulp complex is fundamental to the life of tooth and is a priority for targeting clinical management strategies. Loss of the tooth, jawbone or both, due to periodontal disease, dental caries, trauma or some genetic disorders, affects not only basic mouth functions but aesthetic appearance and quality of life. One novel approach to restore tooth structure is based on biology: regenerative endodontic procedure by application of tissue engineering. Regenerative endodontics is an exciting new concept that seeks to apply the advances in tissue engineering to the regeneration of the pulp-dentin complex. The basic logic behind this approach is that patient-specific tissue-derived cell populations can be used to functionally replace integral tooth tissues. The development of such ‘test tube teeth’ requires precise regulation of the regenerative events in order to achieve proper tooth size and shape, as well as the development of new technologies to facilitate these processes. This article provides an extensive review of literature on the concept of tissue engineering and its application in endodontics, providing an insight into the new developmental approaches on the horizon. Key words:Regenerative, tissue engineering, stem cells, scaffold. PMID:24558528

Developing a Clinical-Grade Cryopreservation Protocol for Human Testicular Tissue and Cells

PubMed Central

Pacchiarotti, Jason; Ramos, Thomas; Howerton, Kyle; Greilach, Scott; Zaragoza, Karina; Olmstead, Marnie; Izadyar, Fariborz

2013-01-01

Recent work in preservation of female fertility as well as new information on the nature of spermatogonial stem cells has prompted an investigation into the possibility of an effective clinical-grade procedure for the cryopreservation of testicular cells and/or tissue. Clinical-grade reagents, validated equipment, and protocols consistent with cGTP/cGMP standards were used in developing a procedure suitable for the safe and effective cryopreservation of human testicular cells and tissues. These procedures were designed to be compliant with the relevant FDA regulations. The procedure proved to effectively cryopreserve both testicular cells and tissue. The cryopreservation of testicular tissue was comparable in most aspects we measured to the cryopreservation of isolated cells, except that the viability of the cells from cryopreserved testicular tissue was found to be significantly higher. On the other hand, cryopreservation of cells is preferred for cell analysis, quality control, and sterility testing. This study demonstrates that testicular tissue and cells from sexual reassignment patients can be successfully cryopreserved with a clinical-grade procedure and important cell populations are not only preserved but also enriched by the process. Further studies will determine whether these findings from hormone-treated patients can be generalized to other patients. PMID:23509810

Development of a biodegradable scaffold with interconnected pores by heat fusion and its application to bone tissue engineering.

PubMed

Shin, Michael; Abukawa, Harutsugi; Troulis, Maria J; Vacanti, Joseph P

2008-03-01

Tissue engineering has been proposed as an approach to alleviate the shortage of donor tissue and organs by combining cells and a biodegradable scaffold as a temporary extracellular matrix. While numerous scaffold fabrication methods have been proposed, tissue formation is typically limited to the surface of the scaffolds in bone tissue engineering applications due to early calcification on the surface. To improve tissue formation, a novel scaffold with a hierarchical interconnected pore structure on two distinct length scales has been developed. Here we present the fabrication process and the application of the scaffold to bone tissue engineering. Porous poly(lactide-co-glycolide) (PLGA) scaffolds were made by combining solvent casting/particulate leaching with heat fusion. Porcine bone marrow-derived mesenchymal stem cells (MSCs) were differentiated into osteoblasts and cultured on these scaffolds in vitro for 2, 4, and 6 weeks. Subsequently, the constructs were assessed using histology and scanning electron microscopy. The bone marrow-derived osteoblasts attached well on these scaffolds. Cells were observed throughout the scaffolds. These initial results show promise for this scaffold to aid in the regeneration of bone. (c) 2007 Wiley Periodicals, Inc.

3D bio-etching of a complex composite-like embryonic tissue.

PubMed

Hazar, Melis; Kim, Yong Tae; Song, Jiho; LeDuc, Philip R; Davidson, Lance A; Messner, William C

2015-08-21

Morphogenesis involves a complex series of cell signaling, migration and differentiation events that are coordinated as tissues self-assemble during embryonic development. Collective cell movements such as those that occur during morphogenesis have typically been studied in 2D with single layers of cultured cells adhering to rigid substrates such as glass or plastic. In vivo, the intricacies of the 3D microenvironment and complex 3D responses are pivotal in the formation of functional tissues. To study such processes as collective cell movements within 3D multilayered tissues, we developed a microfluidic technique capable of producing complex 3D laminar multicellular structures. We call this technique "3D tissue-etching" because it is analogous to techniques used in the microelectromechanics (MEMS) field where complex 3D structures are built by successively removing material from a monolithic solid through subtractive manufacturing. We use a custom-designed microfluidic control system to deliver a range of tissue etching reagents (detergents, chelators, proteases, etc.) to specific regions of multilayered tissues. These tissues were previously isolated by microsurgical excision from embryos of the African claw-toed frog, Xenopus laevis. The ability to shape the 3D form of multicellular tissues and to control 3D stimulation will have a high impact on tissue engineering and regeneration applications in bioengineering and medicine as well as provide significant improvements in the synthesis of highly complex 3D integrated multicellular biosystems.

Surface modification of biomedical and dental implants and the processes of inflammation, wound healing and bone formation.

PubMed

Stanford, Clark M

2010-01-25

Bone adaptation or integration of an implant is characterized by a series of biological reactions that start with bone turnover at the interface (a process of localized necrosis), followed by rapid repair. The wound healing response is guided by a complex activation of macrophages leading to tissue turnover and new osteoblast differentiation on the implant surface. The complex role of implant surface topography and impact on healing response plays a role in biological criteria that can guide the design and development of future tissue-implant surface interfaces.

Utilizing two-photon fluorescence and second harmonic generation microscopy to study human bone marrow mesenchymal stem cell morphogenesis in chitosan scaffold

NASA Astrophysics Data System (ADS)

Su, Ping-Jung; Huang, Chi-Hsiu; Huang, Yi-You; Lee, Hsuan-Sue; Dong, Chen-Yuan

2008-02-01

A major goal of tissue engineering is to cultivate the cartilage in vitro. One approach is to implant the human bone marrow mesenchymal stem cells into the three dimensional biocompatible and biodegradable material. Through the action of the chondrogenic factor TGF-β3, the stem cells can be induced to secrete collagen. In this study, mesenchymal stem cells are implanted on the chitosan scaffold and TGF-β3 was added to produce the cartilage tissue and TP autofluorescence and SHG microscopy was used to image the process of chondrogenesis. With additional development, multiphoton microscopy can be developed into an effective tool for evaluating the quality of tissue engineering products.

In vivo quantification of spatially-varying mechanical properties in developing tissues

PubMed Central

Serwane, Friedhelm; Mongera, Alessandro; Rowghanian, Payam; Kealhofer, David A.; Lucio, Adam A.; Hockenbery, Zachary M.; Campàs, Otger

2017-01-01

It is generally believed that the mechanical properties of the cellular microenvironment and their spatiotemporal variations play a central role in sculpting embryonic tissues, maintaining organ architecture and controlling cell behavior, including cell differentiation. However, no direct in vivo and in situ measurement of mechanical properties within developing 3D tissues and organs has been performed yet. Here we introduce a technique that employs biocompatible ferrofluid microdroplets as local mechanical actuators and allows quantitative spatiotemporal measurements of mechanical properties in vivo. Using this technique, we show that vertebrate body elongation entails spatially-varying tissue mechanics along the anteroposterior axis. Specifically, we find that the zebrafish tailbud is viscoelastic (elastic below a few seconds and fluid after just one minute) and displays decreasing stiffness and increasing fluidity towards its posterior elongating region. This method opens new avenues to study mechanobiology in vivo, both in embryogenesis and in disease processes, including cancer. PMID:27918540

Connexins, pannexins and their channels in fibroproliferative diseases

PubMed Central

Willebrords, Joost; Da Silva, Tereza Cristina; Maes, Michaël; Pereira, Isabel Veloso Alves; Crespo-Yanguas, Sara; Hernandez-Blazquez, Francisco Javier; Dagli, Maria Lúcia Zaidan; Vinken, Mathieu

2017-01-01

Cellular and molecular mechanisms of wound healing, tissue repair and fibrogenesis are established in different organs and are essential for the maintenance of function and tissue integrity after cell injury. These mechanisms are also involved in a plethora of fibroproliferative diseases or organ-specific fibrotic disorders, all of which are associated with the excessive deposition of extracellular matrix components. Fibroblasts, which are key cells in tissue repair and fibrogenesis, rely on communicative cellular networks to ensure efficient control of these processes and to prevent abnormal accumulation of extracellular matrix into the tissue. Despite the significant impact on human health, and thus the epidemiologic relevance, there is still no effective treatment for most fibrosis-related diseases. This paper provides an overview of current concepts and mechanisms involved in the participation of cellular communication via connexin-based pores as well as pannexin-based channels in the processes of tissue repair and fibrogenesis in chronic diseases. Understanding these mechanisms may contribute to the development of new therapeutic strategies to clinically manage fibroproliferative diseases and organ-specific fibrotic disorders. PMID:26914707

Ectopic mineralization disorders of the extracellular matrix of connective tissue: molecular genetics and pathomechanisms of aberrant calcification.

PubMed

Li, Qiaoli; Jiang, Qiujie; Uitto, Jouni

2014-01-01

Ectopic mineralization of connective tissues is a complex process leading to deposition of calcium phosphate complexes in the extracellular matrix, particularly affecting the skin and the arterial blood vessels and common in age-associated disorders. A number of initiating and contributing metabolic and environmental factors are linked to aberrant mineralization in these diseases, making the identification of precise pathomechanistic pathways exceedingly difficult. However, there has been significant recent progress in understanding the ectopic mineralization processes through study of heritable single-gene disorders, which have allowed identification of discrete pathways and contributing factors leading to aberrant connective tissue mineralization. These studies have provided support for the concept of an intricate mineralization/anti-mineralization network present in peripheral connective tissues, providing a perspective to development of pharmacologic approaches to limit the phenotypic consequences of ectopic mineralization. This overview summarizes the current knowledge of ectopic heritable mineralization disorders, with accompanying animal models, focusing on pseudoxanthoma elasticum and generalized arterial calcification of infancy, two autosomal recessive diseases manifesting with extensive connective tissue mineralization in the skin and the cardiovascular system. © 2013.

Ectopic mineralization disorders of the extracellular matrix of connective tissue: Molecular genetics and pathomechanisms of aberrant calcification

PubMed Central

Li, Qiaoli; Jiang, Qiujie; Uitto, Jouni

2013-01-01

Ectopic mineralization of connective tissues is a complex process leading to deposition of calcium phosphate complexes in the extracellular matrix, particularly affecting the skin and the arterial blood vessels and common in age-associated disorders. A number of initiating and contributing metabolic and environmental factors are linked to aberrant mineralization in these diseases, making the identification of precise pathomechanistic pathways exceedingly difficult. However, there has been significant recent progress in understanding the ectopic mineralization processes through study of heritable single-gene disorders, which have allowed identification of discreet pathways and contributing factors leading to aberrant connective tissue mineralization. These studies have provided support for the concept of an intricate mineralization/anti-mineralization network present in peripheral connective tissues, providing a perspective to development of pharmacologic approaches to limit the phenotypic consequences of ectopic mineralization. This overview summarizes the current knowledge of ectopic heritable mineralization disorders, with accompanying animal models, focusing on pseudoxanthoma elasticum and generalized arterial calcification of infancy, two autosomal recessive diseases manifesting with extensive connective tissue mineralization in the skin and the cardiovascular system. PMID:23891698

Intermediate filament protein nestin is expressed in developing meninges.

PubMed

Yay, A; Ozdamar, S; Canoz, O; Baran, M; Tucer, B; Sonmez, M F

2014-01-01

Nestin is a type VI intermediate filament protein known as a marker for progenitor cells that can be mostly found in tissues during the embryonic and fetal periods. In our study, we aimed to determine the expression of nestin in meninges covering the brain tissue at different developmental stages and in the new born. In this study 10 human fetuses in different development stages between developmental weeks 9-34 and a newborn brain tissue were used. Fetuses in paraffin section were stained with H+E and nestin immunohistochemical staining protocol was performed. In this study, in the human meninges intense nestin expression was detected as early as in the 9th week of development. Intensity of this expression gradually decreased in later stages of development and nestin expression still persisted in a small population of newborn meningeal cells. In the present study, nestin positive cells gradually diminished in the developing and maturing meninges during the fetal period. This probably depends on initiation of a decrease in nestin expression and replacement with other tissue-specific intermediate filaments while the differentiation process continues. These differences can make significant contributions to the investigation and diagnosis of various pathological disorders (Tab. 1, Fig. 3, Ref. 36).

Evolving marine biomimetics for regenerative dentistry.

PubMed

Green, David W; Lai, Wing-Fu; Jung, Han-Sung

2014-05-13

New products that help make human tissue and organ regeneration more effective are in high demand and include materials, structures and substrates that drive cell-to-tissue transformations, orchestrate anatomical assembly and tissue integration with biology. Marine organisms are exemplary bioresources that have extensive possibilities in supporting and facilitating development of human tissue substitutes. Such organisms represent a deep and diverse reserve of materials, substrates and structures that can facilitate tissue reconstruction within lab-based cultures. The reason is that they possess sophisticated structures, architectures and biomaterial designs that are still difficult to replicate using synthetic processes, so far. These products offer tantalizing pre-made options that are versatile, adaptable and have many functions for current tissue engineers seeking fresh solutions to the deficiencies in existing dental biomaterials, which lack the intrinsic elements of biofunctioning, structural and mechanical design to regenerate anatomically correct dental tissues both in the culture dish and in vivo.

Evolving Marine Biomimetics for Regenerative Dentistry

PubMed Central

Green, David W.; Lai, Wing-Fu; Jung, Han-Sung

2014-01-01

New products that help make human tissue and organ regeneration more effective are in high demand and include materials, structures and substrates that drive cell-to-tissue transformations, orchestrate anatomical assembly and tissue integration with biology. Marine organisms are exemplary bioresources that have extensive possibilities in supporting and facilitating development of human tissue substitutes. Such organisms represent a deep and diverse reserve of materials, substrates and structures that can facilitate tissue reconstruction within lab-based cultures. The reason is that they possess sophisticated structures, architectures and biomaterial designs that are still difficult to replicate using synthetic processes, so far. These products offer tantalizing pre-made options that are versatile, adaptable and have many functions for current tissue engineers seeking fresh solutions to the deficiencies in existing dental biomaterials, which lack the intrinsic elements of biofunctioning, structural and mechanical design to regenerate anatomically correct dental tissues both in the culture dish and in vivo. PMID:24828293

A model of a code of ethics for tissue banks operating in developing countries.

PubMed

Morales Pedraza, Jorge

2012-12-01

Ethical practice in the field of tissue banking requires the setting of principles, the identification of possible deviations and the establishment of mechanisms that will detect and hinder abuses that may occur during the procurement, processing and distribution of tissues for transplantation. This model of a Code of Ethics has been prepared with the purpose of being used for the elaboration of a Code of Ethics for tissue banks operating in the Latin American and the Caribbean, Asia and the Pacific and the African regions in order to guide the day-to-day operation of these banks. The purpose of this model of Code of Ethics is to assist interested tissue banks in the preparation of their own Code of Ethics towards ensuring that the tissue bank staff support with their actions the mission and values associated with tissue banking.

The case for applying tissue engineering methodologies to instruct human organoid morphogenesis.

PubMed

Marti-Figueroa, Carlos R; Ashton, Randolph S

2017-05-01

Three-dimensional organoids derived from human pluripotent stem cell (hPSC) derivatives have become widely used in vitro models for studying development and disease. Their ability to recapitulate facets of normal human development during in vitro morphogenesis produces tissue structures with unprecedented biomimicry. Current organoid derivation protocols primarily rely on spontaneous morphogenesis processes to occur within 3-D spherical cell aggregates with minimal to no exogenous control. This yields organoids containing microscale regions of biomimetic tissues, but at the macroscale (i.e. 100's of microns to millimeters), the organoids' morphology, cytoarchitecture, and cellular composition are non-biomimetic and variable. The current lack of control over in vitro organoid morphogenesis at the microscale induces aberrations at the macroscale, which impedes realization of the technology's potential to reproducibly form anatomically correct human tissue units that could serve as optimal human in vitro models and even transplants. Here, we review tissue engineering methodologies that could be used to develop powerful approaches for instructing multiscale, 3-D human organoid morphogenesis. Such technological mergers are critically needed to harness organoid morphogenesis as a tool for engineering functional human tissues with biomimetic anatomy and physiology. Human PSC-derived 3-D organoids are revolutionizing the biomedical sciences. They enable the study of development and disease within patient-specific genetic backgrounds and unprecedented biomimetic tissue microenvironments. However, their uncontrolled, spontaneous morphogenesis at the microscale yields inconsistences in macroscale organoid morphology, cytoarchitecture, and cellular composition that limits their standardization and application. Integration of tissue engineering methods with organoid derivation protocols could allow us to harness their potential by instructing standardized in vitro morphogenesis to generate organoids with biomimicry at all scales. Such advancements would enable the use of organoids as a basis for 'next-generation' tissue engineering of functional, anatomically mimetic human tissues and potentially novel organ transplants. Here, we discuss critical aspects of organoid morphogenesis where application of innovative tissue engineering methodologies would yield significant advancement towards this goal. Copyright © 2017. Published by Elsevier Ltd.

Maternal nutrition induces gene expression changes in fetal muscle and adipose tissues in sheep.

PubMed

Peñagaricano, Francisco; Wang, Xin; Rosa, Guilherme Jm; Radunz, Amy E; Khatib, Hasan

2014-11-28

Maternal nutrition during different stages of pregnancy can induce significant changes in the structure, physiology, and metabolism of the offspring. These changes could have important implications on food animal production especially if these perturbations impact muscle and adipose tissue development. Here, we evaluated the impact of different maternal isoenergetic diets, alfalfa haylage (HY; fiber), corn (CN; starch), and dried corn distillers grains (DG; fiber plus protein plus fat), on the transcriptome of fetal muscle and adipose tissues in sheep. Prepartum diets were associated with notable gene expression changes in fetal tissues. In longissimus dorsi muscle, a total of 224 and 823 genes showed differential expression (FDR ≤0.05) in fetuses derived from DG vs. CN and HY vs. CN maternal diets, respectively. Several of these significant genes affected myogenesis and muscle differentiation. In subcutaneous and perirenal adipose tissues, 745 and 208 genes were differentially expressed (FDR ≤0.05), respectively, between CN and DG diets. Many of these genes are involved in adipogenesis, lipogenesis, and adipose tissue development. Pathway analysis revealed that several GO terms and KEGG pathways were enriched (FDR ≤0.05) with differentially expressed genes associated with tissue and organ development, chromatin biology, and different metabolic processes. These findings provide evidence that maternal nutrition during pregnancy can alter the programming of fetal muscle and fat tissues in sheep. The ramifications of the observed gene expression changes, in terms of postnatal growth, body composition, and meat quality of the offspring, warrant future investigation.

Human somatic cells acquire the plasticity to generate embryoid-like metamorphosis via the actin cytoskeleton in injured tissues.

PubMed

Diaz, Jairo A; Murillo, Mauricio F; Mendoza, Jhonan A; Barreto, Ana M; Poveda, Lina S; Sanchez, Lina K; Poveda, Laura C; Mora, Katherine T

2016-01-01

Emergent biological responses develop via unknown processes dependent on physical collision. In hypoxia, when the tissue architecture collapses but the geometric core is stable, actin cytoskeleton filament components emerge, revealing a hidden internal order that identifies how each molecule is reassembled into the original mold, using one common connection, i.e., a fractal self-similarity that guides the system from the beginning in reverse metamorphosis, with spontaneous self-assembly of past forms that mimics an embryoid phenotype. We captured this hidden collective filamentous assemblage in progress: Hypoxic deformed cells enter into intercellular collisions, generate migratory ejected filaments, and produce self-assembly of triangular chiral hexagon complexes; this dynamic geometry guides the microenvironment scaffold in which this biological process is incubated, recapitulating embryonic morphogenesis. In all injured tissues, especially in damaged skeletal (striated) muscle cells, visibly hypertrophic intercalated actin-myosin filaments are organized in zebra stripe pattern along the anterior-posterior axis in the interior of the cell, generating cephalic-caudal polarity segmentation, with a high selective level of immunopositivity for Actin, Alpha Skeletal Muscle antibody and for Neuron-Specific Enolase expression of ectodermal differentiation. The function of actin filaments in emergent responses to tissue injury is to reconstitute, reactivate and orchestrate cellular metamorphosis, involving the re-expression of fetal genes, providing evidence of the reverse flow of genetic information within a biological system. The resultant embryoid phenotype emerges as a microscopic fractal template copy of the organization of the whole body, likely allowing the modification and reprogramming of the phenotype of the tumor in which these structures develop, as well as establishing a reverse primordial microscopic mold to collectively re-form cellular building blocks to regenerate injured tissues. Tumorigenesis mimics a self-organizing process of early embryo development. All malignant tumors produce fetal proteins, we now know from which these proteins proceed. Embryoid-like metamorphosis phenomena would represent the anatomical and functional entity of the injury stem cell niche. The sufficiently fast identification, isolation, culture, and expansion of these self-organized structures or genetically derived products could, in our opinion, be used to develop new therapeutic strategies against cancer and in regenerative medicine.

Human somatic cells acquire the plasticity to generate embryoid-like metamorphosis via the actin cytoskeleton in injured tissues

PubMed Central

Diaz, Jairo A; Murillo, Mauricio F; Mendoza, Jhonan A; Barreto, Ana M; Poveda, Lina S; Sanchez, Lina K; Poveda, Laura C; Mora, Katherine T

2016-01-01

Emergent biological responses develop via unknown processes dependent on physical collision. In hypoxia, when the tissue architecture collapses but the geometric core is stable, actin cytoskeleton filament components emerge, revealing a hidden internal order that identifies how each molecule is reassembled into the original mold, using one common connection, i.e., a fractal self-similarity that guides the system from the beginning in reverse metamorphosis, with spontaneous self-assembly of past forms that mimics an embryoid phenotype. We captured this hidden collective filamentous assemblage in progress: Hypoxic deformed cells enter into intercellular collisions, generate migratory ejected filaments, and produce self-assembly of triangular chiral hexagon complexes; this dynamic geometry guides the microenvironment scaffold in which this biological process is incubated, recapitulating embryonic morphogenesis. In all injured tissues, especially in damaged skeletal (striated) muscle cells, visibly hypertrophic intercalated actin-myosin filaments are organized in zebra stripe pattern along the anterior-posterior axis in the interior of the cell, generating cephalic-caudal polarity segmentation, with a high selective level of immunopositivity for Actin, Alpha Skeletal Muscle antibody and for Neuron-Specific Enolase expression of ectodermal differentiation. The function of actin filaments in emergent responses to tissue injury is to reconstitute, reactivate and orchestrate cellular metamorphosis, involving the re-expression of fetal genes, providing evidence of the reverse flow of genetic information within a biological system. The resultant embryoid phenotype emerges as a microscopic fractal template copy of the organization of the whole body, likely allowing the modification and reprogramming of the phenotype of the tumor in which these structures develop, as well as establishing a reverse primordial microscopic mold to collectively re-form cellular building blocks to regenerate injured tissues. Tumorigenesis mimics a self-organizing process of early embryo development. All malignant tumors produce fetal proteins, we now know from which these proteins proceed. Embryoid-like metamorphosis phenomena would represent the anatomical and functional entity of the injury stem cell niche. The sufficiently fast identification, isolation, culture, and expansion of these self-organized structures or genetically derived products could, in our opinion, be used to develop new therapeutic strategies against cancer and in regenerative medicine. PMID:27725917

Three-dimensional histology: tools and application to quantitative assessment of cell-type distribution in rabbit heart

PubMed Central

Burton, Rebecca A.B.; Lee, Peter; Casero, Ramón; Garny, Alan; Siedlecka, Urszula; Schneider, Jürgen E.; Kohl, Peter; Grau, Vicente

2014-01-01

Aims Cardiac histo-anatomical organization is a major determinant of function. Changes in tissue structure are a relevant factor in normal and disease development, and form targets of therapeutic interventions. The purpose of this study was to test tools aimed to allow quantitative assessment of cell-type distribution from large histology and magnetic resonance imaging- (MRI) based datasets. Methods and results Rabbit heart fixation during cardioplegic arrest and MRI were followed by serial sectioning of the whole heart and light-microscopic imaging of trichrome-stained tissue. Segmentation techniques developed specifically for this project were applied to segment myocardial tissue in the MRI and histology datasets. In addition, histology slices were segmented into myocytes, connective tissue, and undefined. A bounding surface, containing the whole heart, was established for both MRI and histology. Volumes contained in the bounding surface (called ‘anatomical volume’), as well as that identified as containing any of the above tissue categories (called ‘morphological volume’), were calculated. The anatomical volume was 7.8 cm3 in MRI, and this reduced to 4.9 cm3 after histological processing, representing an ‘anatomical’ shrinkage by 37.2%. The morphological volume decreased by 48% between MRI and histology, highlighting the presence of additional tissue-level shrinkage (e.g. an increase in interstitial cleft space). The ratio of pixels classified as containing myocytes to pixels identified as non-myocytes was roughly 6:1 (61.6 vs. 9.8%; the remaining fraction of 28.6% was ‘undefined’). Conclusion Qualitative and quantitative differentiation between myocytes and connective tissue, using state-of-the-art high-resolution serial histology techniques, allows identification of cell-type distribution in whole-heart datasets. Comparison with MRI illustrates a pronounced reduction in anatomical and morphological volumes during histology processing. PMID:25362175

3D bioprinting for drug discovery and development in pharmaceutics.

PubMed

Peng, Weijie; Datta, Pallab; Ayan, Bugra; Ozbolat, Veli; Sosnoski, Donna; Ozbolat, Ibrahim T

2017-07-15

Successful launch of a commercial drug requires significant investment of time and financial resources wherein late-stage failures become a reason for catastrophic failures in drug discovery. This calls for infusing constant innovations in technologies, which can give reliable prediction of efficacy, and more importantly, toxicology of the compound early in the drug discovery process before clinical trials. Though computational advances have resulted in more rationale in silico designing, in vitro experimental studies still require gaining industry confidence and improving in vitro-in vivo correlations. In this quest, due to their ability to mimic the spatial and chemical attributes of native tissues, three-dimensional (3D) tissue models have now proven to provide better results for drug screening compared to traditional two-dimensional (2D) models. However, in vitro fabrication of living tissues has remained a bottleneck in realizing the full potential of 3D models. Recent advances in bioprinting provide a valuable tool to fabricate biomimetic constructs, which can be applied in different stages of drug discovery research. This paper presents the first comprehensive review of bioprinting techniques applied for fabrication of 3D tissue models for pharmaceutical studies. A comparative evaluation of different bioprinting modalities is performed to assess the performance and ability of fabricating 3D tissue models for pharmaceutical use as the critical selection of bioprinting modalities indeed plays a crucial role in efficacy and toxicology testing of drugs and accelerates the drug development cycle. In addition, limitations with current tissue models are discussed thoroughly and future prospects of the role of bioprinting in pharmaceutics are provided to the reader. Present advances in tissue biofabrication have crucial role to play in aiding the pharmaceutical development process achieve its objectives. Advent of three-dimensional (3D) models, in particular, is viewed with immense interest by the community due to their ability to mimic in vivo hierarchical tissue architecture and heterogeneous composition. Successful realization of 3D models will not only provide greater in vitro-in vivo correlation compared to the two-dimensional (2D) models, but also eventually replace pre-clinical animal testing, which has their own shortcomings. Amongst all fabrication techniques, bioprinting- comprising all the different modalities (extrusion-, droplet- and laser-based bioprinting), is emerging as the most viable fabrication technique to create the biomimetic tissue constructs. Notwithstanding the interest in bioprinting by the pharmaceutical development researchers, it can be seen that there is a limited availability of comparative literature which can guide the proper selection of bioprinting processes and associated considerations, such as the bioink selection for a particular pharmaceutical study. Thus, this work emphasizes these aspects of bioprinting and presents them in perspective of differential requirements of different pharmaceutical studies like in vitro predictive toxicology, high-throughput screening, drug delivery and tissue-specific efficacies. Moreover, since bioprinting techniques are mostly applied in regenerative medicine and tissue engineering, a comparative analysis of similarities and differences are also expounded to help researchers make informed decisions based on contemporary literature. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Hyaluronan (HA) interacting proteins RHAMM and hyaluronidase impact prostate cancer cell behavior and invadopodia formation in 3D HA-based hydrogels.

PubMed

Gurski, Lisa A; Xu, Xian; Labrada, Lyana N; Nguyen, Ngoc T; Xiao, Longxi; van Golen, Kenneth L; Jia, Xinqiao; Farach-Carson, Mary C

2012-01-01

To study the individual functions of hyaluronan interacting proteins in prostate cancer (PCa) motility through connective tissues, we developed a novel three-dimensional (3D) hyaluronic acid (HA) hydrogel assay that provides a flexible, quantifiable, and physiologically relevant alternative to current methods. Invasion in this system reflects the prevalence of HA in connective tissues and its role in the promotion of cancer cell motility and tissue invasion, making the system ideal to study invasion through bone marrow or other HA-rich connective tissues. The bio-compatible cross-linking process we used allows for direct encapsulation of cancer cells within the gel where they adopt a distinct, cluster-like morphology. Metastatic PCa cells in these hydrogels develop fingerlike structures, "invadopodia", consistent with their invasive properties. The number of invadopodia, as well as cluster size, shape, and convergence, can provide a quantifiable measure of invasive potential. Among candidate hyaluronan interacting proteins that could be responsible for the behavior we observed, we found that culture in the HA hydrogel triggers invasive PCa cells to differentially express and localize receptor for hyaluronan mediated motility (RHAMM)/CD168 which, in the absence of CD44, appears to contribute to PCa motility and invasion by interacting with the HA hydrogel components. PCa cell invasion through the HA hydrogel also was found to depend on the activity of hyaluronidases. Studies shown here reveal that while hyaluronidase activity is necessary for invadopodia and inter-connecting cluster formation, activity alone is not sufficient for acquisition of invasiveness to occur. We therefore suggest that development of invasive behavior in 3D HA-based systems requires development of additional cellular features, such as activation of motility associated pathways that regulate formation of invadopodia. Thus, we report development of a 3D system amenable to dissection of biological processes associated with cancer cell motility through HA-rich connective tissues.

Confocal microscopy with strip mosaicing for rapid imaging over large areas of excised tissue

PubMed Central

Li, Yongbiao; Larson, Bjorg; Peterson, Gary; Seltzer, Emily; Toledo-Crow, Ricardo; Rajadhyaksha, Milind

2013-01-01

Abstract. Confocal mosaicing microscopy is a developing technology platform for imaging tumor margins directly in freshly excised tissue, without the processing required for conventional pathology. Previously, mosaicing on 12-×-12  mm2 of excised skin tissue from Mohs surgery and detection of basal cell carcinoma margins was demonstrated in 9 min. Last year, we reported the feasibility of a faster approach called “strip mosaicing,” which was demonstrated on a 10-×-10  mm2 of tissue in 3 min. Here we describe further advances in instrumentation, software, and speed. A mechanism was also developed to flatten tissue in order to enable consistent and repeatable acquisition of images over large areas. We demonstrate mosaicing on 10-×-10  mm2 of skin tissue with 1-μm lateral resolution in 90 s. A 2.5-×-3.5  cm2 piece of breast tissue was scanned with 0.8-μm lateral resolution in 13 min. Rapid mosaicing of confocal images on large areas of fresh tissue potentially offers a means to perform pathology at the bedside. Imaging of tumor margins with strip mosaicing confocal microscopy may serve as an adjunct to conventional (frozen or fixed) pathology for guiding surgery. PMID:23389736

Natural Rubber Nanocomposite with Human-Tissue-Like Mechanical Characteristic

NASA Astrophysics Data System (ADS)

Murniati, Riri; Novita, Nanda; Sutisna; Wibowo, Edy; Iskandar, Ferry; Abdullah, Mikrajuddin

2017-07-01

The blends of synthetic rubber and natural rubber with nanosilica were prepared using a blending technique in presence of different filler volume fraction. The effect of filler on morphological and mechanical characteristics was studied. Utilization of human cadaver in means of medical study has been commonly used primarily as tools of medical teaching and training such as surgery. Nonetheless, human cadaver brought inevitable problems. So it is necessary to find a substitute material that can be used to replace cadavers. In orthopaedics, the materials that resemble in mechanical properties to biological tissues are elastomers such as natural rubber (latex) and synthetic rubber (polyurethanes, silicones). This substitution material needs to consider the potential of Indonesia to help the development of the nation. Indonesia is the second largest country producer of natural rubber in the world. This paper aims to contribute to adjusting the mechanical properties of tissue-mimicking materials (TMMs) to the recommended range of biological tissue value and thus allow the development of phantoms with greater stability and similarity to human tissues. Repeatability for the phantom fabrication process was also explored. Characteristics were then compared to the control and mechanical characteristics of different human body part tissue. Nanosilica is the best filler to produce the best nanocomposite similarities with human tissue. We produced composites that approaching the properties of human internal tissues.

Recent advances in hydrogels for cartilage tissue engineering.

PubMed

Vega, S L; Kwon, M Y; Burdick, J A

2017-01-30

Articular cartilage is a load-bearing tissue that lines the surface of bones in diarthrodial joints. Unfortunately, this avascular tissue has a limited capacity for intrinsic repair. Treatment options for articular cartilage defects include microfracture and arthroplasty; however, these strategies fail to generate tissue that adequately restores damaged cartilage. Limitations of current treatments for cartilage defects have prompted the field of cartilage tissue engineering, which seeks to integrate engineering and biological principles to promote the growth of new cartilage to replace damaged tissue. To date, a wide range of scaffolds and cell sources have emerged with a focus on recapitulating the microenvironments present during development or in adult tissue, in order to induce the formation of cartilaginous constructs with biochemical and mechanical properties of native tissue. Hydrogels have emerged as a promising scaffold due to the wide range of possible properties and the ability to entrap cells within the material. Towards improving cartilage repair, hydrogel design has advanced in recent years to improve their utility. Some of these advances include the development of improved network crosslinking (e.g. double-networks), new techniques to process hydrogels (e.g. 3D printing) and better incorporation of biological signals (e.g. controlled release). This review summarises these innovative approaches to engineer hydrogels towards cartilage repair, with an eye towards eventual clinical translation.

Aloe Vera for Tissue Engineering Applications

PubMed Central

Rahman, Shekh; Carter, Princeton; Bhattarai, Narayan

2017-01-01

Aloe vera, also referred as Aloe barbadensis Miller, is a succulent plant widely used for biomedical, pharmaceutical and cosmetic applications. Aloe vera has been used for thousands of years. However, recent significant advances have been made in the development of aloe vera for tissue engineering applications. Aloe vera has received considerable attention in tissue engineering due to its biodegradability, biocompatibility, and low toxicity properties. Aloe vera has been reported to have many biologically active components. The bioactive components of aloe vera have effective antibacterial, anti-inflammatory, antioxidant, and immune-modulatory effects that promote both tissue regeneration and growth. The aloe vera plant, its bioactive components, extraction and processing, and tissue engineering prospects are reviewed in this article. The use of aloe vera as tissue engineering scaffolds, gels, and films is discussed, with a special focus on electrospun nanofibers. PMID:28216559

Aloe Vera for Tissue Engineering Applications.

PubMed

Rahman, Shekh; Carter, Princeton; Bhattarai, Narayan

2017-02-14

Aloe vera, also referred as Aloe barbadensis Miller, is a succulent plant widely used for biomedical, pharmaceutical and cosmetic applications. Aloe vera has been used for thousands of years. However, recent significant advances have been made in the development of aloe vera for tissue engineering applications. Aloe vera has received considerable attention in tissue engineering due to its biodegradability, biocompatibility, and low toxicity properties. Aloe vera has been reported to have many biologically active components. The bioactive components of aloe vera have effective antibacterial, anti-inflammatory, antioxidant, and immune-modulatory effects that promote both tissue regeneration and growth. The aloe vera plant, its bioactive components, extraction and processing, and tissue engineering prospects are reviewed in this article. The use of aloe vera as tissue engineering scaffolds, gels, and films is discussed, with a special focus on electrospun nanofibers.

Gene and Metabolite Regulatory Network Analysis of Early Developing Fruit Tissues Highlights New Candidate Genes for the Control of Tomato Fruit Composition and Development1[C][W][OA

PubMed Central

Mounet, Fabien; Moing, Annick; Garcia, Virginie; Petit, Johann; Maucourt, Michael; Deborde, Catherine; Bernillon, Stéphane; Le Gall, Gwénaëlle; Colquhoun, Ian; Defernez, Marianne; Giraudel, Jean-Luc; Rolin, Dominique; Rothan, Christophe; Lemaire-Chamley, Martine

2009-01-01

Variations in early fruit development and composition may have major impacts on the taste and the overall quality of ripe tomato (Solanum lycopersicum) fruit. To get insights into the networks involved in these coordinated processes and to identify key regulatory genes, we explored the transcriptional and metabolic changes in expanding tomato fruit tissues using multivariate analysis and gene-metabolite correlation networks. To this end, we demonstrated and took advantage of the existence of clear structural and compositional differences between expanding mesocarp and locular tissue during fruit development (12–35 d postanthesis). Transcriptome and metabolome analyses were carried out with tomato microarrays and analytical methods including proton nuclear magnetic resonance and liquid chromatography-mass spectrometry, respectively. Pairwise comparisons of metabolite contents and gene expression profiles detected up to 37 direct gene-metabolite correlations involving regulatory genes (e.g. the correlations between glutamine, bZIP, and MYB transcription factors). Correlation network analyses revealed the existence of major hub genes correlated with 10 or more regulatory transcripts and embedded in a large regulatory network. This approach proved to be a valuable strategy for identifying specific subsets of genes implicated in key processes of fruit development and metabolism, which are therefore potential targets for genetic improvement of tomato fruit quality. PMID:19144766

Alzheimer's disease: neuroprogesterone, epoxycholesterol, and ABC transporters as determinants of neurodesmosterol tissue levels and its role in amyloid protein processing.

PubMed

Javitt, Norman B

2013-01-01

Evidence is emerging that during the development of Alzheimer's disease (AD), changes in the synthesis and metabolism of cholesterol and progesterone are occurring that may or may not affect the progression of the disease. The concept arose from the recognition that dehydrocholesterol 24-reductase (DHCR24/Seladin-1), one of the nine enzymes in the endoplasmic reticulum that determines the transformation of lanosterol to cholesterol, is selectively reduced in late AD. As a consequence, the tissue level of desmosterol increases, affecting the expression of ABC transporters and the structure of lipid rafts, both determinants of amyloid-β processing. However, the former effect is considered beneficial and the latter detrimental to processing. Other determinants of desmosterol tissue levels are 24,25 epoxycholesterol and the ABCG1 and ABCG4 transporters. Progesterone and its metabolites are determinants of tissue levels of desmosterol and several other sterol intermediates in cholesterol synthesis. Animal models indicate marked elevations in the tissue levels of these sterols at early time frames in the progression of neurodegenerative diseases. The low level of neuroprogesterone and metabolites in AD are consonant with the low level of desmosterol and may have a role in amyloid-β processing. The sparse data that has accumulated appears to be a sufficient basis for proposing a systematic evaluation of the biologic roles of sterol intermediates in the slowly progressive neurodegeneration characteristic of AD.

Parametric approaches to micro-scale characterization of tissue volumes in vivo and ex vivo: Imaging microvasculature, attenuation, birefringence, and stiffness (Conference Presentation)

NASA Astrophysics Data System (ADS)

Sampson, David D.; Chin, Lixin; Gong, Peijun; Wijesinghe, Philip; Es'haghian, Shaghayegh; Allen, Wesley M.; Klyen, Blake R.; Kirk, Rodney W.; Kennedy, Brendan F.; McLaughlin, Robert A.

2016-03-01

INVITED TALK Advances in imaging tissue microstructure in living subjects, or in freshly excised tissue with minimum preparation and processing, are important for future diagnosis and surgical guidance in the clinical setting, particularly for application to cancer. Whilst microscopy methods continue to advance on the cellular scale and medical imaging is well established on the scale of the whole tumor or organ, it is attractive to consider imaging the tumor environment on the micro-scale, between that of cells and whole tissues. Such a scenario is ideally suited to optical coherence tomography (OCT), with the twin attractions of requiring little or no tissue preparation, and in vivo capability. OCT's intrinsic scattering contrast reveals many morphological features of tumors, but is frequently ineffective in revealing other important aspects, such as microvasculature, or in reliably distinguishing tumor from uninvolved stroma. To address these shortcomings, we are developing several advances on the basic OCT approach. We are exploring speckle fluctuations to image tissue microvasculature and we have been developing several parametric approaches to tissue micro-scale characterization. Our approaches extract, from a three-dimensional OCT data set, a two-dimensional image of an optical parameter, such as attenuation or birefringence, or a mechanical parameter, such as stiffness, that aids in characterizing the tissue. This latter method, termed optical coherence elastography, parallels developments in ultrasound and magnetic resonance imaging. Parametric imaging of birefringence and of stiffness both show promise in addressing the important issue of differentiating cancer from uninvolved stroma in breast tissue.

Tissue vascularization through 3D printing: Will technology bring us flow?

PubMed

Paulsen, S J; Miller, J S

2015-05-01

Though in vivo models provide the most physiologically relevant environment for studying tissue function, in vitro studies provide researchers with explicit control over experimental conditions and the potential to develop high throughput testing methods. In recent years, advancements in developmental biology research and imaging techniques have significantly improved our understanding of the processes involved in vascular development. However, the task of recreating the complex, multi-scale vasculature seen in in vivo systems remains elusive. 3D bioprinting offers a potential method to generate controlled vascular networks with hierarchical structure approaching that of in vivo networks. Bioprinting is an interdisciplinary field that relies on advances in 3D printing technology along with advances in imaging and computational modeling, which allow researchers to monitor cellular function and to better understand cellular environment within the printed tissue. As bioprinting technologies improve with regards to resolution, printing speed, available materials, and automation, 3D printing could be used to generate highly controlled vascularized tissues in a high throughput manner for use in regenerative medicine and the development of in vitro tissue models for research in developmental biology and vascular diseases. © 2015 Wiley Periodicals, Inc.

X-ray micro-beam techniques and phase contrast tomography applied to biomaterials

NASA Astrophysics Data System (ADS)

Fratini, Michela; Campi, Gaetano; Bukreeva, Inna; Pelliccia, Daniele; Burghammer, Manfred; Tromba, Giuliana; Cancedda, Ranieri; Mastrogiacomo, Maddalena; Cedola, Alessia

2015-12-01

A deeper comprehension of the biomineralization (BM) process is at the basis of tissue engineering and regenerative medicine developments. Several in-vivo and in-vitro studies were dedicated to this purpose via the application of 2D and 3D diagnostic techniques. Here, we develop a new methodology, based on different complementary experimental techniques (X-ray phase contrast tomography, micro-X-ray diffraction and micro-X-ray fluorescence scanning technique) coupled to new analytical tools. A qualitative and quantitative structural investigation, from the atomic to the micrometric length scale, is obtained for engineered bone tissues. The high spatial resolution achieved by X-ray scanning techniques allows us to monitor the bone formation at the first-formed mineral deposit at the organic-mineral interface within a porous scaffold. This work aims at providing a full comprehension of the morphology and functionality of the biomineralization process, which is of key importance for developing new drugs for preventing and healing bone diseases and for the development of bio-inspired materials.

Three-dimensional bioprinting using self-assembling scalable scaffold-free “tissue strands” as a new bioink

PubMed Central

Yu, Yin; Moncal, Kazim K.; Li, Jianqiang; Peng, Weijie; Rivero, Iris; Martin, James A.; Ozbolat, Ibrahim T.

2016-01-01

Recent advances in bioprinting have granted tissue engineers the ability to assemble biomaterials, cells, and signaling molecules into anatomically relevant functional tissues or organ parts. Scaffold-free fabrication has recently attracted a great deal of interest due to the ability to recapitulate tissue biology by using self-assembly, which mimics the embryonic development process. Despite several attempts, bioprinting of scale-up tissues at clinically-relevant dimensions with closely recapitulated tissue biology and functionality is still a major roadblock. Here, we fabricate and engineer scaffold-free scalable tissue strands as a novel bioink material for robotic-assisted bioprinting technologies. Compare to 400 μm-thick tissue spheroids bioprinted in a liquid delivery medium into confining molds, near 8 cm-long tissue strands with rapid fusion and self-assemble capabilities are bioprinted in solid form for the first time without any need for a scaffold or a mold support or a liquid delivery medium, and facilitated native-like scale-up tissues. The prominent approach has been verified using cartilage strands as building units to bioprint articular cartilage tissue. PMID:27346373

Therapeutic possibilities and opportunities for comparative oncopathology.

PubMed

Kaiser, H E

1993-01-01

In reviewing abnormal growth, we may distinguish autonomous and nonautonomous growth processes. The highest diversification is reached in the autonomous non-self-limiting processes, the malignant neoplasms which, if not treated, are characterized by extensive growth and progression. In their development these processes exhibit autonomy on one hand and heterogeneity on the other. Neoplastic and related diseases are extremely complex. It is unacceptable to view them exclusively as genetic or metabolic diseases, or merely as the tumor itself, including its progressive stages, as evidenced in neoplastic metastasis. All these characteristics appear in the different types of neoplastic malignomas, e.g. genetic variations in the neoplastic cells from the normal cells of the parent tissue(s). Included here are tumor progression and cloning of the neoplastic cells, stagewise development of host metabolism and of tumor metabolism; neoplastic hereditary and endocrine-like syndromes as well as paraneoplastic syndromes and cachexia. Neoplastic progression, as observed in the metastatic cascade, derives from the cells of the primary tumor. In contrast, multiple primary tumors originate from different host tissues, whereas the syndromes themselves constitute a symptom complex developing in a neoplasm-bearing host and cannot be assigned to local or distant spread of neoplasms. The only possible explanation for these apparently contrasting processes lies in the interaction of tumor and host metabolism, which seemingly varies in tumor-bearing hosts and in those cases where the tumor has been surgical removed. Antigens and other compounds again show an increase with the usually ensuing secondary tumor spread, a course which provides the basis for most deaths from cancer.

Enzyme-crosslinked gene-activated matrix for the induction of mesenchymal stem cells in osteochondral tissue regeneration.

PubMed

Lee, Yi-Hsuan; Wu, Hsi-Chin; Yeh, Chia-Wei; Kuan, Chen-Hsiang; Liao, Han-Tsung; Hsu, Horng-Chaung; Tsai, Jui-Che; Sun, Jui-Sheng; Wang, Tzu-Wei

2017-11-01

The development of osteochondral tissue engineering is an important issue for the treatment of traumatic injury or aging associated joint disease. However, the different compositions and mechanical properties of cartilage and subchondral bone show the complexity of this tissue interface, making it challenging for the design and fabrication of osteochondral graft substitute. In this study, a bilayer scaffold is developed to promote the regeneration of osteochondral tissue within a single integrated construct. It has the capacity to serve as a gene delivery platform to promote transfection of human mesenchymal stem cells (hMSCs) and the functional osteochondral tissues formation. For the subchondral bone layer, the bone matrix with organic (type I collagen, Col) and inorganic (hydroxyapatite, Hap) composite scaffold has been developed through mineralization of hydroxyapatite nanocrystals oriented growth on collagen fibrils. We also prepare multi-shell nanoparticles in different layers with a calcium phosphate core and DNA/calcium phosphate shells conjugated with polyethyleneimine to act as non-viral vectors for delivery of plasmid DNA encoding BMP2 and TGF-β3, respectively. Microbial transglutaminase is used as a cross-linking agent to crosslink the bilayer scaffold. The ability of this scaffold to act as a gene-activated matrix is demonstrated with successful transfection efficiency. The results show that the sustained release of plasmids from gene-activated matrix can promote prolonged transgene expression and stimulate hMSCs differentiation into osteogenic and chondrogenic lineages by spatial and temporal control within the bilayer composite scaffold. This improved delivery method may enhance the functionalized composite graft to accelerate healing process for osteochondral tissue regeneration. In this study, a gene-activated matrix (GAM) to promote the growth of both cartilage and subchondral bone within a single integrated construct is developed. It has the capacity to promote transfection of human mesenchymal stem cells (hMSCs) and the functional osteochondral tissues formation. The results show that the sustained release of plasmids including TGF-beta and BMP-2 from GAM could promote prolonged transgene expression and stimulate hMSCs differentiation into the osteogenic and chondrogenic lineages by spatial control manner. This improved delivery method should enhance the functionalized composite graft to accelerate healing process in vitro and in vivo for osteochondral tissue regeneration. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Development of 3D woven cellular structures for adaptive composites based on thermoplastic hybrid yarns

NASA Astrophysics Data System (ADS)

Sennewald, C.; Vorhof, M.; Schegner, P.; Hoffmann, G.; Cherif, C.; Boblenz, J.; Sinapius, M.; Hühne, C.

2018-05-01

Flexible cellular 3D structures with structure-inherent compliance made of fiber-reinforced composites have repeatedly aroused the interest of international research groups. Such structures offer the possibility to meet the increasing demand for flexible and adaptive structures. The aim of this paper is the development of cellular 3D structures based on weaving technology. Considering the desired geometry of the 3D structure, algorithms are developed for the formation of geometry through tissue sub-areas. Subsequently, these sub-areas are unwound into the weaving level and appropriate weave patterns are developed. A particular challenge is the realization of compliant mechanisms in the woven fabric. This can be achieved either by combining different materials or, in particular, by implementing large stiffness gradients by means of varying the woven fabrics thickness, whereas differences in wall thickness have to be realized with a factor of 1:10. A manufacturing technology based on the weaving process is developed for the realization of the developed 3D cellular structures. To this end, solutions for the processing of hybrid thermoplastic materials (e.g. tapes), solutions for the integration of inlays in the weaving process (thickening of partial areas), and solutions for tissue retraction, as well as for the fabric pull-off (linear pull-off system) are being developed. In this way, woven cellular 3D structures with woven outer layers and woven joint areas (compliance) can be realized in a single process step and are subsequently characterized.

SU-8 microprobe with microelectrodes for monitoring electrical impedance in living tissues.

PubMed

Tijero, M; Gabriel, G; Caro, J; Altuna, A; Hernández, R; Villa, R; Berganzo, J; Blanco, F J; Salido, R; Fernández, L J

2009-04-15

This paper presents a minimally invasive needle-shaped probe capable of monitoring the electrical impedance of living tissues. This microprobe consists of a 160 microm thick SU-8 substrate containing four planar platinum (Pt) microelectrodes. We design the probe to minimize damage to the surrounding tissue and to be stiff enough to be inserted in living tissues. The proposed batch fabrication process is low cost and low time consuming. The microelectrodes obtained with this process are strongly adhered to the SU-8 substrate and their impedance does not depend on frequency variation. In vitro experiments are compared with previously developed Si and SiC based microprobes and results suggest that it is preferable to use the SU-8 based microprobes due to their flexibility and low cost. The microprobe is assembled on a flexible printed circuit FPC with a conductive glue, packaged with epoxy and wired to the external instrumentation. This flexible probe is inserted into a rat kidney without fracturing and succeeds in demonstrating the ischemia monitoring.

Microsecond-pulsed dielectric barrier discharge plasma stimulation of tissue macrophages for treatment of peripheral vascular disease

PubMed Central

Miller, V.; Lin, A.; Kako, F.; Gabunia, K.; Kelemen, S.; Brettschneider, J.; Fridman, G.; Fridman, A.; Autieri, M.

2015-01-01

Angiogenesis is the formation of new blood vessels from pre-existing vessels and normally occurs during the process of inflammatory reactions, wound healing, tissue repair, and restoration of blood flow after injury or insult. Stimulation of angiogenesis is a promising and an important step in the treatment of peripheral artery disease. Reactive oxygen species have been shown to be involved in stimulation of this process. For this reason, we have developed and validated a non-equilibrium atmospheric temperature and pressure short-pulsed dielectric barrier discharge plasma system, which can non-destructively generate reactive oxygen species and other active species at the surface of the tissue being treated. We show that this plasma treatment stimulates the production of vascular endothelial growth factor, matrix metalloproteinase-9, and CXCL 1 that in turn induces angiogenesis in mouse aortic rings in vitro. This effect may be mediated by the direct effect of plasma generated reactive oxygen species on tissue. PMID:26543345

Microsecond-pulsed dielectric barrier discharge plasma stimulation of tissue macrophages for treatment of peripheral vascular disease

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, V., E-mail: vmiller@coe.drexel.edu; Lin, A.; Brettschneider, J.

Angiogenesis is the formation of new blood vessels from pre-existing vessels and normally occurs during the process of inflammatory reactions, wound healing, tissue repair, and restoration of blood flow after injury or insult. Stimulation of angiogenesis is a promising and an important step in the treatment of peripheral artery disease. Reactive oxygen species have been shown to be involved in stimulation of this process. For this reason, we have developed and validated a non-equilibrium atmospheric temperature and pressure short-pulsed dielectric barrier discharge plasma system, which can non-destructively generate reactive oxygen species and other active species at the surface of themore » tissue being treated. We show that this plasma treatment stimulates the production of vascular endothelial growth factor, matrix metalloproteinase-9, and CXCL 1 that in turn induces angiogenesis in mouse aortic rings in vitro. This effect may be mediated by the direct effect of plasma generated reactive oxygen species on tissue.« less

caTIES: a grid based system for coding and retrieval of surgical pathology reports and tissue specimens in support of translational research.

PubMed

Crowley, Rebecca S; Castine, Melissa; Mitchell, Kevin; Chavan, Girish; McSherry, Tara; Feldman, Michael

2010-01-01

The authors report on the development of the Cancer Tissue Information Extraction System (caTIES)--an application that supports collaborative tissue banking and text mining by leveraging existing natural language processing methods and algorithms, grid communication and security frameworks, and query visualization methods. The system fills an important need for text-derived clinical data in translational research such as tissue-banking and clinical trials. The design of caTIES addresses three critical issues for informatics support of translational research: (1) federation of research data sources derived from clinical systems; (2) expressive graphical interfaces for concept-based text mining; and (3) regulatory and security model for supporting multi-center collaborative research. Implementation of the system at several Cancer Centers across the country is creating a potential network of caTIES repositories that could provide millions of de-identified clinical reports to users. The system provides an end-to-end application of medical natural language processing to support multi-institutional translational research programs.

Mesothelial cells in tissue repair and fibrosis.

PubMed

Mutsaers, Steven E; Birnie, Kimberly; Lansley, Sally; Herrick, Sarah E; Lim, Chuan-Bian; Prêle, Cecilia M

2015-01-01

Mesothelial cells are fundamental to the maintenance of serosal integrity and homeostasis and play a critical role in normal serosal repair following injury. However, when normal repair mechanisms breakdown, mesothelial cells take on a profibrotic role, secreting inflammatory, and profibrotic mediators, differentiating and migrating into the injured tissues where they contribute to fibrogenesis. The development of new molecular and cell tracking techniques has made it possible to examine the origin of fibrotic cells within damaged tissues and to elucidate the roles they play in inflammation and fibrosis. In addition to secreting proinflammatory mediators and contributing to both coagulation and fibrinolysis, mesothelial cells undergo mesothelial-to-mesenchymal transition, a process analogous to epithelial-to-mesenchymal transition, and become fibrogenic cells. Fibrogenic mesothelial cells have now been identified in tissues where they have not previously been thought to occur, such as within the parenchyma of the fibrotic lung. These findings show a direct role for mesothelial cells in fibrogenesis and open therapeutic strategies to prevent or reverse the fibrotic process.

Levofloxacin-loaded star poly(ε-caprolactone) scaffolds by additive manufacturing.

PubMed

Puppi, Dario; Piras, Anna Maria; Pirosa, Alessandro; Sandreschi, Stefania; Chiellini, Federica

2016-03-01

The employment of a tissue engineering scaffold able to release an antimicrobial agent with a controlled kinetics represents an effective tool for the treatment of infected tissue defects as well as for the prevention of scaffolds implantation-related infectious complications. This research activity was aimed at the development of additively manufactured star poly(ε-caprolactone) (*PCL) scaffolds loaded with levofloxacin, investigated as antimicrobial fluoroquinolone model. For this purpose a computer-aided wet-spinning technique allowing functionalizing the scaffold during the fabrication process was explored. Scaffolds with customized composition, microstructure and anatomical external shape were developed by optimizing the processing parameters. Morphological, thermal and mechanical characterization showed that drug loading did not compromise the fabrication process and the final performance of the scaffolds. The developed *PCL scaffolds showed a sustained in vitro release of the loaded antibiotic for 5 weeks. The proposed computer-aided wet-spinning technique appears well suited for the fabrication of anatomical scaffolds endowed with levofloxacin-releasing properties to be tested in vivo for the regeneration of long bone critical size defects in a rabbit model.

Characterization of visceral and subcutaneous adipose tissue transcriptome in pregnant women with and without spontaneous labor at term: Implication of alternative splicing in the metabolic adaptations of adipose tissue to parturition

PubMed Central

Mazaki-Tovi, Shali; Tarca, Adi L.; Vaisbuch, Edi; Kusanovic, Juan Pedro; Than, Nandor Gabor; Chaiworapongsa, Tinnakorn; Dong, Zhong; Hassan, Sonia S; Romero, Roberto

2018-01-01

OBJECTIVE The aim of this study was to determine gene expression and splicing changes associated with parturition and regions (visceral vs subcutaneous) of the adipose tissue of pregnant women. STUDY DESIGN The transcriptome of visceral and abdominal subcutaneous adipose tissue from pregnant women at term with (n=15) and without (n=25) spontaneous labor was profiled with Affymetrix GeneChip Human Exon 1.0 ST array. Overall gene expression changes and differential exon usage rate were compared between patient groups and adipose tissue regions (paired analyses). Selected genes were tested by quantitative reverse transcription–polymerase chain reaction. RESULTS Four hundred eighty-two genes were differentially expressed between visceral and subcutaneous fat of pregnant women with spontaneous labor at term (q-value <0.1; fold change >1.5). Biological processes enriched in this comparison included tissue and vasculature development, inflammatory and metabolic pathways. Differential splicing was found for 42 genes (q-value <0.1; difference FIRMA scores >2) between adipose tissue regions of women not in labor. Differential exon usage associated with parturition was found for three genes (LIMS1, HSPA5 and GSTK1) in subcutaneous tissues. CONCLUSION We show for the first time evidence of implication of mRNA splicing and processing machinery in the subcutaneous adipose tissue of women in labor compared to those without labor. PMID:26994472

Characterization of visceral and subcutaneous adipose tissue transcriptome in pregnant women with and without spontaneous labor at term: implication of alternative splicing in the metabolic adaptations of adipose tissue to parturition.

PubMed

Mazaki-Tovi, Shali; Tarca, Adi L; Vaisbuch, Edi; Kusanovic, Juan Pedro; Than, Nandor Gabor; Chaiworapongsa, Tinnakorn; Dong, Zhong; Hassan, Sonia S; Romero, Roberto

2016-10-01

The aim of this study was to determine gene expression and splicing changes associated with parturition and regions (visceral vs. subcutaneous) of the adipose tissue of pregnant women. The transcriptome of visceral and abdominal subcutaneous adipose tissue from pregnant women at term with (n=15) and without (n=25) spontaneous labor was profiled with the Affymetrix GeneChip Human Exon 1.0 ST array. Overall gene expression changes and the differential exon usage rate were compared between patient groups (unpaired analyses) and adipose tissue regions (paired analyses). Selected genes were tested by quantitative reverse transcription-polymerase chain reaction. Four hundred and eighty-two genes were differentially expressed between visceral and subcutaneous fat of pregnant women with spontaneous labor at term (q-value <0.1; fold change >1.5). Biological processes enriched in this comparison included tissue and vasculature development as well as inflammatory and metabolic pathways. Differential splicing was found for 42 genes [q-value <0.1; differences in Finding Isoforms using Robust Multichip Analysis scores >2] between adipose tissue regions of women not in labor. Differential exon usage associated with parturition was found for three genes (LIMS1, HSPA5, and GSTK1) in subcutaneous tissues. We show for the first time evidence of implication of mRNA splicing and processing machinery in the subcutaneous adipose tissue of women in labor compared to those without labor.

Combinatory approach for developing silk fibroin scaffolds for cartilage regeneration.

PubMed

Ribeiro, Viviana P; da Silva Morais, Alain; Maia, F Raquel; Canadas, Raphael F; Costa, João B; Oliveira, Ana L; Oliveira, Joaquim M; Reis, Rui L

2018-05-01

Several processing technologies and engineering strategies have been combined to create scaffolds with superior performance for efficient tissue regeneration. Cartilage tissue is a good example of that, presenting limited self-healing capacity together with a high elasticity and load-bearing properties. In this work, novel porous silk fibroin (SF) scaffolds derived from horseradish peroxidase (HRP)-mediated crosslinking of highly concentrated aqueous SF solution (16 wt%) in combination with salt-leaching and freeze-drying methodologies were developed for articular cartilage tissue engineering (TE) applications. The HRP-crosslinked SF scaffolds presented high porosity (89.3 ± 0.6%), wide pore distribution and high interconnectivity (95.9 ± 0.8%). Moreover, a large swelling capacity and favorable degradation rate were observed up to 30 days, maintaining the porous-like structure and β-sheet conformational integrity obtained with salt-leaching and freeze-drying processing. The in vitro studies supported human adipose-derived stem cells (hASCs) adhesion, proliferation, and high glycosaminoglycans (GAGs) synthesis under chondrogenic culture conditions. Furthermore, the chondrogenic differentiation of hASCs was assessed by the expression of chondrogenic-related markers (collagen type II, Sox-9 and Aggrecan) and deposition of cartilage-specific extracellular matrix for up to 28 days. The cartilage engineered constructs also presented structural integrity as their mechanical properties were improved after chondrogenic culturing. Subcutaneous implantation of the scaffolds in CD-1 mice demonstrated no necrosis or calcification, and deeply tissue ingrowth. Collectively, the structural properties and biological performance of these porous HRP-crosslinked SF scaffolds make them promising candidates for cartilage regeneration. In cartilage tissue engineering (TE), several processing technologies have been combined to create scaffolds for efficient tissue repair. In our study, we propose novel silk fibroin (SF) scaffolds derived from enzymatically crosslinked SF hydrogels processed by salt-leaching and freeze-drying technologies, for articular cartilage applications. Though these scaffolds, we were able to combine the elastic properties of hydrogel-based systems, with the stability, resilience and controlled porosity of scaffolds processed via salt-leaching and freeze-drying technologies. SF protein has been extensively explored for TE applications, as a result of its mechanical strength, elasticity, biocompatibility, and biodegradability. Thus, the structural, mechanical and biological performance of the proposed scaffolds potentiates their use as three-dimensional matrices for cartilage regeneration. Copyright © 2018 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

A deep learning approach to estimate chemically-treated collagenous tissue nonlinear anisotropic stress-strain responses from microscopy images.

PubMed

Liang, Liang; Liu, Minliang; Sun, Wei

2017-11-01

Biological collagenous tissues comprised of networks of collagen fibers are suitable for a broad spectrum of medical applications owing to their attractive mechanical properties. In this study, we developed a noninvasive approach to estimate collagenous tissue elastic properties directly from microscopy images using Machine Learning (ML) techniques. Glutaraldehyde-treated bovine pericardium (GLBP) tissue, widely used in the fabrication of bioprosthetic heart valves and vascular patches, was chosen to develop a representative application. A Deep Learning model was designed and trained to process second harmonic generation (SHG) images of collagen networks in GLBP tissue samples, and directly predict the tissue elastic mechanical properties. The trained model is capable of identifying the overall tissue stiffness with a classification accuracy of 84%, and predicting the nonlinear anisotropic stress-strain curves with average regression errors of 0.021 and 0.031. Thus, this study demonstrates the feasibility and great potential of using the Deep Learning approach for fast and noninvasive assessment of collagenous tissue elastic properties from microstructural images. In this study, we developed, to our best knowledge, the first Deep Learning-based approach to estimate the elastic properties of collagenous tissues directly from noninvasive second harmonic generation images. The success of this study holds promise for the use of Machine Learning techniques to noninvasively and efficiently estimate the mechanical properties of many structure-based biological materials, and it also enables many potential applications such as serving as a quality control tool to select tissue for the manufacturing of medical devices (e.g. bioprosthetic heart valves). Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Effects of Epidermal Growth Factor-Loaded Mucoadhesive Films on Wounded Oral Tissue Rafts

PubMed Central

Ramineni, Sandeep K.; Fowler, Craig B.; Fisher, Paul D.; Cunningham, Larry L.; Puleo, David A.

2015-01-01

Current treatments for traumatic oral mucosal wounds include the gold standard of autologous tissue and alternative tissue engineered grafts. While use of autografts has disadvantages of minimal availability of oral keratinized tissue, second surgery, and donor site discomfort, tissue engineered grafts are limited by their unavailability as off-the-shelf products owing to their fabrication time of 4–8 weeks. Hence, the current work aimed to develop a potentially cost-effective, readily available device capable of enhancing native mucosal regeneration. Considering the key role of epidermal growth factor (EGF) in promoting mucosal wound regeneration and the advantages of mucoadhesive delivery systems, mucoadhesive films composed of polyvinylpyrrolidone and carboxymethylcellulose were developed to provide sustained release of EGF for minimum of 6 hours. Bioactivity of released EGF supernatants was then confirmed by its ability to promote proliferation of BALB/3T3 fibroblasts. Efficacy of the developed system was then investigated in vitro using buccal tissues (ORL 300-FT) as a potential replacement for small animal studies. Although the mucoadhesive films achieved their desired role of delivering bioactive EGF in a sustained manner, treatment with EGF, irrespective of its release from the films or solubilized in medium, caused a hyperparakeratotic response from in vitro tissues with distinguishable histological features including thickening of the spinous layer, intra- and intercellular edema, and pyknotic nuclei. These significant morphological changes were associated with no improvements in wound closure. These observations raise questions about the potential of using in vitro tissues as a wound healing model and substitute for small animal studies. The mucoadhesive delivery system developed, however, with its potential for sustained release of bioactive growth factors and small molecules, may be loaded with other desired compounds, with or without EGF, to accelerate the process of wound healing. PMID:25729882

Autoradiographic study on healing process of cysteamine-induced duodenal ulcer in rat. Possible importance of Brunner's glands in ulcer healing

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fuse, Y.; Tsuchihashi, Y.; Sugihara, H.

1988-09-01

The healing process of cysteamine-induced duodenal ulcer was studied by (/sup 3/H)thymidine autoradiography. After the development of ulcer in the duodenum, cell proliferation was markedly activated not only in the crypts but also in the Brunner's glands near the ulcer. In the initial stages of ulcer healing, they both contributed to form the surface covering regenerating epithelium. Granulation tissue also proliferated at the base of the ulcer. In later stages of ulcer healing, new crypts were formed in the floor of the ulcer. New villi regenerated from these crypts and Brunner's glands regenerated by proliferation in situ. The ulcer basemore » then was completely covered with new villi and granulation tissue was replaced by dense fibrous connective tissue. The present study suggested that the Brunner's glands, together with the crypts of Lieberkuehn, play an important role in the healing process of cysteamine-induced duodenal ulcer.« less

Mathematical modeling of degradation for bulk-erosive polymers: applications in tissue engineering scaffolds and drug delivery systems.

PubMed

Chen, Yuhang; Zhou, Shiwei; Li, Qing

2011-03-01

The degradation of polymeric biomaterials, which are widely exploited in tissue engineering and drug delivery systems, has drawn significant attention in recent years. This paper aims to develop a mathematical model that combines stochastic hydrolysis and mass transport to simulate the polymeric degradation and erosion process. The hydrolysis reaction is modeled in a discrete fashion by a fundamental stochastic process and an additional autocatalytic effect induced by the local carboxylic acid concentration in terms of the continuous diffusion equation. Illustrative examples of microparticles and tissue scaffolds demonstrate the applicability of the model. It is found that diffusive transport plays a critical role in determining the degradation pathway, whilst autocatalysis makes the degradation size dependent. The modeling results show good agreement with experimental data in the literature, in which the hydrolysis rate, polymer architecture and matrix size actually work together to determine the characteristics of the degradation and erosion processes of bulk-erosive polymer devices. The proposed degradation model exhibits great potential for the design optimization of drug carriers and tissue scaffolds. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Progress in development of bioderived materials for dermal wound healing.

PubMed

Da, Lin-Cui; Huang, Yi-Zhou; Xie, Hui-Qi

2017-10-01

Treatment of acute and chronic wounds is one of the primary challenges faced by doctors. Bioderived materials have significant potential clinical value in tissue injury treatment and defect reconstruction. Various strategies, including drug loading, addition of metallic element(s), cross-linking and combining two or more distinct types of materials with complementary features, have been used to synthesize more suitable materials for wound healing. In this review, we describe the recent developments made in the processing of bioderived materials employed for cutaneous wound healing, including newly developed materials such as keratin and soy protein. The focus was on the key properties of the bioderived materials that have shown great promise in improving wound healing, restoration and reconstruction. With their good biocompatibility, nontoxic catabolites, microinflammation characteristics, as well as their ability to induce tissue regeneration and reparation, the bioderived materials have great potential for skin tissue repair.

Progress in development of bioderived materials for dermal wound healing

PubMed Central

Da, Lin-Cui; Huang, Yi-Zhou

2017-01-01

Abstract Treatment of acute and chronic wounds is one of the primary challenges faced by doctors. Bioderived materials have significant potential clinical value in tissue injury treatment and defect reconstruction. Various strategies, including drug loading, addition of metallic element(s), cross-linking and combining two or more distinct types of materials with complementary features, have been used to synthesize more suitable materials for wound healing. In this review, we describe the recent developments made in the processing of bioderived materials employed for cutaneous wound healing, including newly developed materials such as keratin and soy protein. The focus was on the key properties of the bioderived materials that have shown great promise in improving wound healing, restoration and reconstruction. With their good biocompatibility, nontoxic catabolites, microinflammation characteristics, as well as their ability to induce tissue regeneration and reparation, the bioderived materials have great potential for skin tissue repair. PMID:29026647

Tissue-electronics interfaces: from implantable devices to engineered tissues

NASA Astrophysics Data System (ADS)

Feiner, Ron; Dvir, Tal

2018-01-01

Biomedical electronic devices are interfaced with the human body to extract precise medical data and to interfere with tissue function by providing electrical stimuli. In this Review, we outline physiologically and pathologically relevant tissue properties and processes that are important for designing implantable electronic devices. We summarize design principles for flexible and stretchable electronics that adapt to the mechanics of soft tissues, such as those including conducting polymers, liquid metal alloys, metallic buckling and meandering architectures. We further discuss technologies for inserting devices into the body in a minimally invasive manner and for eliminating them without further intervention. Finally, we introduce the concept of integrating electronic devices with biomaterials and cells, and we envision how such technologies may lead to the development of bionic organs for regenerative medicine.

Quantitative real-time analysis of collective cancer invasion and dissemination

NASA Astrophysics Data System (ADS)

Ewald, Andrew J.

2015-05-01

A grand challenge in biology is to understand the cellular and molecular basis of tissue and organ level function in mammals. The ultimate goals of such efforts are to explain how organs arise in development from the coordinated actions of their constituent cells and to determine how molecularly regulated changes in cell behavior alter the structure and function of organs during disease processes. Two major barriers stand in the way of achieving these goals: the relative inaccessibility of cellular processes in mammals and the daunting complexity of the signaling environment inside an intact organ in vivo. To overcome these barriers, we have developed a suite of tissue isolation, three dimensional (3D) culture, genetic manipulation, nanobiomaterials, imaging, and molecular analysis techniques to enable the real-time study of cell biology within intact tissues in physiologically relevant 3D environments. This manuscript introduces the rationale for 3D culture, reviews challenges to optical imaging in these cultures, and identifies current limitations in the analysis of complex experimental designs that could be overcome with improved imaging, imaging analysis, and automated classification of the results of experimental interventions.

Development of a pericardial acellular matrix biomaterial: biochemical and mechanical effects of cell extraction.

PubMed

Courtman, D W; Pereira, C A; Kashef, V; McComb, D; Lee, J M; Wilson, G J

1994-06-01

There is evidence to suggest that the cellular components of homografts and bioprosthetic xenografts may contribute to calcification or immunogenic reactions. A four-step detergent and enzymatic extraction process has been developed to remove cellular components from bovine pericardial tissue. The process results in an acellular matrix material consisting primarily of elastin, insoluble collagen, and tightly bound glycosaminoglycans. Light and electron microscopy confirmed that nearly all cellular constituents are removed without ultrastructural evidence of damage to fibrous components. Collagen denaturation temperatures remained unaltered. Biochemical analysis confirmed the retention of collagen and elastin and some differential extraction of glycosaminoglycans. Low strain rate fracture testing and high strain rate viscoelastic characterization showed that, with the exception of slightly increased stress relaxation, the mechanical properties of the fresh tissue were preserved in the pericardial acellular matrix. Crosslinking of the material in glutaraldehyde or poly(glycidyl ether) produced mechanical changes consistent with the same treatments of fresh tissue. The pericardial acellular matrix is a promising approach to the production of biomaterials for heart valve or cardiovascular patching applications.

A gradient method for the quantitative analysis of cell movement and tissue flow and its application to the analysis of multicellular Dictyostelium development.

PubMed

Siegert, F; Weijer, C J; Nomura, A; Miike, H

1994-01-01

We describe the application of a novel image processing method, which allows quantitative analysis of cell and tissue movement in a series of digitized video images. The result is a vector velocity field showing average direction and velocity of movement for every pixel in the frame. We apply this method to the analysis of cell movement during different stages of the Dictyostelium developmental cycle. We analysed time-lapse video recordings of cell movement in single cells, mounds and slugs. The program can correctly assess the speed and direction of movement of either unlabelled or labelled cells in a time series of video images depending on the illumination conditions. Our analysis of cell movement during multicellular development shows that the entire morphogenesis of Dictyostelium is characterized by rotational cell movement. The analysis of cell and tissue movement by the velocity field method should be applicable to the analysis of morphogenetic processes in other systems such as gastrulation and neurulation in vertebrate embryos.

Simulations and experiments of photon propagation in biological tissue and liquid crystal waveguides

NASA Astrophysics Data System (ADS)

Lines, Collin M.

The development of non-invasive methods to probe human tissue is an ongoing challenge in biomedical optics. In vivo measurements by conventional methods are limited by the mean free path (MFP) of a photon, which is governed by the spatial distribution of chromophores and the absorption and scattering properties of the tissue. As one of the strongest chromophores in human tissues, hemoglobin concentrations in human tissue greatly affect the MFP of photons in visible wavelengths (i.e. bruising). Changes in the concentration of hemoglobin and other chromophores within the tissue (minor trauma causing a contusion, increased bilirubin due to jaundice, etc.) will affect the MFP, leading to a visibly different appearance (color) of the tissue. As color perception is a complex physiological process, these changes are diffcult to quantify by human observation alone. The transport of hemoglobin and its breakdown products in tissue is related to a number of medical conditions that could benefit from a non-invasive method to determine the hemoglobin levels.

Osteopontin is a Novel Marker of Pancreatic Ductal Tissues and of Undifferentiated Pancreatic Precursors in Mice

PubMed Central

Kilic, Gamze; Wang, Junfeng; Sosa-Pineda, Beatriz

2008-01-01

Matricellular proteins mediate both tissue morphogenesis and tissue homeostasis in important ways because they modulate cell-matrix and cell-cell interactions. In this study, we found that the matricellular protein osteopontin (Opn) is a novel marker of undifferentiated pancreatic precursors and pancreatic ductal tissues in mice. Our analysis also underscored a specific, dynamic profile of Opn expression in embryonic pancreatic tissues that suggests the participation of this protein’s function in processes involving cell migration, cell-cell interactions, or both. Surprisingly, our analysis of Opn-deficient pancreata did not reveal obvious alterations in the morphology or differentiation of these tissues. Therefore, in embryonic pancreatic tissues, it is possible that other proteins act redundantly to Opn or that this protein’s function is dispensable for pancreas development. Finally, the maintenance of Opn expression in pancreatic tissues of adults argues for a possible function of this protein in injury and pathologic responses. PMID:16518820

Formalizing Knowledge in Multi-Scale Agent-Based Simulations

PubMed Central

Somogyi, Endre; Sluka, James P.; Glazier, James A.

2017-01-01

Multi-scale, agent-based simulations of cellular and tissue biology are increasingly common. These simulations combine and integrate a range of components from different domains. Simulations continuously create, destroy and reorganize constituent elements causing their interactions to dynamically change. For example, the multi-cellular tissue development process coordinates molecular, cellular and tissue scale objects with biochemical, biomechanical, spatial and behavioral processes to form a dynamic network. Different domain specific languages can describe these components in isolation, but cannot describe their interactions. No current programming language is designed to represent in human readable and reusable form the domain specific knowledge contained in these components and interactions. We present a new hybrid programming language paradigm that naturally expresses the complex multi-scale objects and dynamic interactions in a unified way and allows domain knowledge to be captured, searched, formalized, extracted and reused. PMID:29338063

Formalizing Knowledge in Multi-Scale Agent-Based Simulations.

PubMed

Somogyi, Endre; Sluka, James P; Glazier, James A

2016-10-01

Multi-scale, agent-based simulations of cellular and tissue biology are increasingly common. These simulations combine and integrate a range of components from different domains. Simulations continuously create, destroy and reorganize constituent elements causing their interactions to dynamically change. For example, the multi-cellular tissue development process coordinates molecular, cellular and tissue scale objects with biochemical, biomechanical, spatial and behavioral processes to form a dynamic network. Different domain specific languages can describe these components in isolation, but cannot describe their interactions. No current programming language is designed to represent in human readable and reusable form the domain specific knowledge contained in these components and interactions. We present a new hybrid programming language paradigm that naturally expresses the complex multi-scale objects and dynamic interactions in a unified way and allows domain knowledge to be captured, searched, formalized, extracted and reused.

A high performance biometric signal and image processing method to reveal blood perfusion towards 3D oxygen saturation mapping

NASA Astrophysics Data System (ADS)

Imms, Ryan; Hu, Sijung; Azorin-Peris, Vicente; Trico, Michaël.; Summers, Ron

2014-03-01

Non-contact imaging photoplethysmography (PPG) is a recent development in the field of physiological data acquisition, currently undergoing a large amount of research to characterize and define the range of its capabilities. Contact-based PPG techniques have been broadly used in clinical scenarios for a number of years to obtain direct information about the degree of oxygen saturation for patients. With the advent of imaging techniques, there is strong potential to enable access to additional information such as multi-dimensional blood perfusion and saturation mapping. The further development of effective opto-physiological monitoring techniques is dependent upon novel modelling techniques coupled with improved sensor design and effective signal processing methodologies. The biometric signal and imaging processing platform (bSIPP) provides a comprehensive set of features for extraction and analysis of recorded iPPG data, enabling direct comparison with other biomedical diagnostic tools such as ECG and EEG. Additionally, utilizing information about the nature of tissue structure has enabled the generation of an engineering model describing the behaviour of light during its travel through the biological tissue. This enables the estimation of the relative oxygen saturation and blood perfusion in different layers of the tissue to be calculated, which has the potential to be a useful diagnostic tool.

Identifying the architecture of a supracellular actomyosin network that induces tissue folding

NASA Astrophysics Data System (ADS)

Yevick, Hannah; Stoop, Norbert; Dunkel, Jorn; Martin, Adam

During embryonic development, the establishment of correct tissue form ensures proper tissue function. Yet, how the thousands of cells within a tissue coordinate force production to sculpt tissue shape is poorly understood. One important tissue shape change is tissue folding where a cell sheet bends to form a closed tube. Drosophila (fruit fly) embryos undergo such a folding event, called ventral furrow formation. The ventral furrow is associated with a supracellular network of actin and myosin, where actin-myosin fibers assemble and connect between cells. It is not known how this tissue-wide network grows and connects over time, how reproducible it is between embryos, and what determines its architecture. Here, we used topological feature analysis to quantitatively and dynamically map the connections and architecture of this supracellular network across hundreds of cells in the folding tissue. We identified the importance of the cell unit in setting up the tissue-scale architecture of the network. Our mathematical framework allows us to explore stereotypic properties of the myosin network such that we can investigate the reproducibility of mechanical connections for a morphogenetic process. NIH F32.

Dynamic Proteomic Characteristics and Network Integration Revealing Key Proteins for Two Kernel Tissue Developments in Popcorn.

PubMed

Dong, Yongbin; Wang, Qilei; Zhang, Long; Du, Chunguang; Xiong, Wenwei; Chen, Xinjian; Deng, Fei; Ma, Zhiyan; Qiao, Dahe; Hu, Chunhui; Ren, Yangliu; Li, Yuling

2015-01-01

The formation and development of maize kernel is a complex dynamic physiological and biochemical process that involves the temporal and spatial expression of many proteins and the regulation of metabolic pathways. In this study, the protein profiles of the endosperm and pericarp at three important developmental stages were analyzed by isobaric tags for relative and absolute quantification (iTRAQ) labeling coupled with LC-MS/MS in popcorn inbred N04. Comparative quantitative proteomic analyses among developmental stages and between tissues were performed, and the protein networks were integrated. A total of 6,876 proteins were identified, of which 1,396 were nonredundant. Specific proteins and different expression patterns were observed across developmental stages and tissues. The functional annotation of the identified proteins revealed the importance of metabolic and cellular processes, and binding and catalytic activities for the development of the tissues. The whole, endosperm-specific and pericarp-specific protein networks integrated 125, 9 and 77 proteins, respectively, which were involved in 54 KEGG pathways and reflected their complex metabolic interactions. Confirmation for the iTRAQ endosperm proteins by two-dimensional gel electrophoresis showed that 44.44% proteins were commonly found. However, the concordance between mRNA level and the protein abundance varied across different proteins, stages, tissues and inbred lines, according to the gene cloning and expression analyses of four relevant proteins with important functions and different expression levels. But the result by western blot showed their same expression tendency for the four proteins as by iTRAQ. These results could provide new insights into the developmental mechanisms of endosperm and pericarp, and grain formation in maize.

Dynamic Proteomic Characteristics and Network Integration Revealing Key Proteins for Two Kernel Tissue Developments in Popcorn

PubMed Central

Du, Chunguang; Xiong, Wenwei; Chen, Xinjian; Deng, Fei; Ma, Zhiyan; Qiao, Dahe; Hu, Chunhui; Ren, Yangliu; Li, Yuling

2015-01-01

The formation and development of maize kernel is a complex dynamic physiological and biochemical process that involves the temporal and spatial expression of many proteins and the regulation of metabolic pathways. In this study, the protein profiles of the endosperm and pericarp at three important developmental stages were analyzed by isobaric tags for relative and absolute quantification (iTRAQ) labeling coupled with LC-MS/MS in popcorn inbred N04. Comparative quantitative proteomic analyses among developmental stages and between tissues were performed, and the protein networks were integrated. A total of 6,876 proteins were identified, of which 1,396 were nonredundant. Specific proteins and different expression patterns were observed across developmental stages and tissues. The functional annotation of the identified proteins revealed the importance of metabolic and cellular processes, and binding and catalytic activities for the development of the tissues. The whole, endosperm-specific and pericarp-specific protein networks integrated 125, 9 and 77 proteins, respectively, which were involved in 54 KEGG pathways and reflected their complex metabolic interactions. Confirmation for the iTRAQ endosperm proteins by two-dimensional gel electrophoresis showed that 44.44% proteins were commonly found. However, the concordance between mRNA level and the protein abundance varied across different proteins, stages, tissues and inbred lines, according to the gene cloning and expression analyses of four relevant proteins with important functions and different expression levels. But the result by western blot showed their same expression tendency for the four proteins as by iTRAQ. These results could provide new insights into the developmental mechanisms of endosperm and pericarp, and grain formation in maize. PMID:26587848

Object-oriented business process analysis of the cooperative soft tissue sarcoma trial of the german society for paediatric oncology and haematology (GPOH).

PubMed

Weber, R; Knaup, P; Knietitg, R; Haux, R; Merzweiler, A; Mludek, V; Schilling, F H; Wiedemann, T

2001-01-01

The German Society for Paediatric Oncology and Haematology (GPOH) runs nation-wide multicentre clinical trials to improve the treatment of children suffering from malignant diseases. We want to provide methods and tools to support the centres of these trials in developing trial specific modules for the computer-based DOcumentation System for Paediatric Oncology (DOSPO). For this we carried out an object-oriented business process analysis for the Cooperative Soft Tissue Sarcoma Trial at the Olgahospital Stuttgart for Child and Adolescent Medicine. The result is a comprehensive business process model consisting of UML-diagrams and use case specifications. We recommend the object-oriented business process analysis as a method for the definition of requirements in information processing projects in the field of clinical trials in general. For this our model can serve as basis because it slightly can be adjusted to each type of clinical trial.

Biomimetic Randall's plaque as an in vitro model system for studying the role of acidic biopolymers in idiopathic stone formation.

PubMed

Chidambaram, Archana; Rodriguez, Douglas; Khan, Saeed; Gower, Laurie

2015-01-01

Randall's plaque (RP) deposits seem to be consistent among the most common type of kidney stone formers, idiopathic calcium oxalate stone formers. This group forms calcium oxalate renal stones without any systemic symptoms, which contributes to the difficulty of understanding and treating this painful and recurring disease. Thus, the development of an in vitro model system to study idiopathic nephrolithiasis, beginning with RP pathogenesis, can help in identifying how plaques and subsequently stones form. One main theory of RP formation is that calcium phosphate deposits initially form in the basement membrane of the thin loops of Henle, which then fuse and spread into the interstitial tissue, and ultimately make their way across the urothelium, where upon exposure to the urine, the mineralized tissue serves as a nidus for overgrowth with calcium oxalate into a stone. Our group has found that many of the unusual morphologies found in RP and stones, such as concentrically laminated spherulites and mineralized collagenous tissue, can be reproduced in vitro using a polymer-induced liquid precursor (PILP) process, in which acidic polypeptides induce a liquid phase amorphous precursor to the mineral, yielding non-equilibrium crystal morphologies. Given that there are many acidic proteins and polysaccharides present in the renal tissue and urine, we have put forth the hypothesis that the PILP system may be involved in urolithiasis. Therefore, our goal is to develop an in vitro model system of these two stages of composite stone formation to study the role that various acidic macromolecules may play. In our initial experiments presented here, the development of "biomimetic" RP was investigated, which will then serve as a nidus for calcium oxalate overgrowth studies. To mimic the tissue environment, MatriStem(®) (ACell, Inc.), a decellularized porcine urinary bladder matrix was used, because it has both an intact epithelial basement membrane surface and a tunica propria layer, thus providing the two types of matrix constituents found associated with mineral in the early stages of RP formation. We found that when using the PILP process to mineralize this tissue matrix, the two sides led to dramatically different mineral textures, and they bore a striking resemblance to native RP, which was not seen in the tissue mineralized via the classical crystal nucleation and growth process. The interstitium side predominantly consisted of collagen-associated mineral, while the luminal side had much less mineral, which appeared to be tiny spherules embedded within the basement membrane. Although these studies are only preliminary, they support our hypothesis that kidney stones may involve non-classical crystallization pathways induced by the large variety of macromolecular species in the urinary environment. We believe that mineralization of native tissue scaffolds is useful for developing a model system of stone formation, with the ultimate goal of developing strategies to avoid RP and its detrimental consequences in stone formation, or developing therapeutic treatments to prevent or cure the disease. Supported by NIDDK grant RO1DK092311.

Chitin Scaffolds in Tissue Engineering

PubMed Central

Jayakumar, Rangasamy; Chennazhi, Krishna Prasad; Srinivasan, Sowmya; Nair, Shantikumar V.; Furuike, Tetsuya; Tamura, Hiroshi

2011-01-01

Tissue engineering/regeneration is based on the hypothesis that healthy stem/progenitor cells either recruited or delivered to an injured site, can eventually regenerate lost or damaged tissue. Most of the researchers working in tissue engineering and regenerative technology attempt to create tissue replacements by culturing cells onto synthetic porous three-dimensional polymeric scaffolds, which is currently regarded as an ideal approach to enhance functional tissue regeneration by creating and maintaining channels that facilitate progenitor cell migration, proliferation and differentiation. The requirements that must be satisfied by such scaffolds include providing a space with the proper size, shape and porosity for tissue development and permitting cells from the surrounding tissue to migrate into the matrix. Recently, chitin scaffolds have been widely used in tissue engineering due to their non-toxic, biodegradable and biocompatible nature. The advantage of chitin as a tissue engineering biomaterial lies in that it can be easily processed into gel and scaffold forms for a variety of biomedical applications. Moreover, chitin has been shown to enhance some biological activities such as immunological, antibacterial, drug delivery and have been shown to promote better healing at a faster rate and exhibit greater compatibility with humans. This review provides an overview of the current status of tissue engineering/regenerative medicine research using chitin scaffolds for bone, cartilage and wound healing applications. We also outline the key challenges in this field and the most likely directions for future development and we hope that this review will be helpful to the researchers working in the field of tissue engineering and regenerative medicine. PMID:21673928

Regenerative endodontics.

PubMed

Simon, S; Smith, A J

2014-03-01

Significant advances in our understanding of the biological processes involved in tooth development and repair at the cellular and molecular levels have underpinned the newly emerging area of regenerative endodontics. Development of treatment protocols based on exploiting the natural wound healing properties of the dental pulp and applying tissue engineering principles has allowed reporting of case series showing preservation of tissue vitality and apexogenesis. To review current case series reporting regenerative endodontics. Current treatment approaches tend to stimulate more reparative than regenerative responses in respect of the new tissue generated, which often does not closely resemble the physiological structure of dentine-pulp. However, despite these biological limitations, such techniques appear to offer significant promise for improved treatment outcomes. Improved biological outcomes will likely emerge from the many experimental studies being reported and will further contribute to improvements in clinical treatment protocols.

Harnessing the power of macrophages/monocytes for enhanced bone tissue engineering.

PubMed

Dong, Lei; Wang, Chunming

2013-06-01

Bone tissue engineering has attracted considerable attention as a promising treatment modality for severe bone degeneration. The pressing need for more sophisticated and fully functional bone substitutes has spurred a refocus on the development of bone constructs in a way more comparable to the physiological process. Current research is increasingly revealing the central roles of macrophages/monocytes in regulating bone development and repair, so we propose that these immunocytes can play a similar pivotal role in directing engineered bone regeneration. Accordingly, we discuss two possible strategies to exemplify how the distinctive power of macrophages/monocytes--particularly their cytokine-secretion ability and chemotactic response to foreign materials--can be harnessed to enhance the performance of bone tissue engineering applications. Copyright © 2013 Elsevier Ltd. All rights reserved.

Connective tissue growth factor (CTGF) from basics to clinics.

PubMed

Ramazani, Yasaman; Knops, Noël; Elmonem, Mohamed A; Nguyen, Tri Q; Arcolino, Fanny Oliveira; van den Heuvel, Lambert; Levtchenko, Elena; Kuypers, Dirk; Goldschmeding, Roel

2018-03-21

Connective tissue growth factor, also known as CCN2, is a cysteine-rich matricellular protein involved in the control of biological processes, such as cell proliferation, differentiation, adhesion and angiogenesis, as well as multiple pathologies, such as tumor development and tissue fibrosis. Here, we describe the molecular and biological characteristics of CTGF, its regulation and various functions in the spectrum of development and regeneration to fibrosis. We further outline the preclinical and clinical studies concerning compounds targeting CTGF in various pathologies with the focus on heart, lung, liver, kidney and solid organ transplantation. Finally, we address the advances and pitfalls of translational fibrosis research and provide suggestions to move towards a better management of fibrosis. Copyright © 2017 International Society of Matrix Biology. Published by Elsevier B.V. All rights reserved.

Characterizing the mechanical behavior of the zebrafish germ layers

NASA Astrophysics Data System (ADS)

Kealhofer, David; Serwane, Friedhelm; Mongera, Alessandro; Rowghanian, Payam; Lucio, Adam; Campàs, Otger

Organ morphogenesis and the development of the animal body plan involve complex spatial and temporal control of tissue- and cell-level mechanics. A prime example is the generation of stresses by individual cells to reorganize the tissue. These processes have remained poorly understood due to a lack of techniques to characterize the local constitutive law of the material, which relates local cellular forces to the resulting tissue flows. We have developed a method for quantitative, local in vivo study of material properties in living tissue using magnetic droplet probes. We use this technique to study the material properties of the different zebrafish germ layers using aggregates of zebrafish mesendodermal and ectodermal cells as a model system. These aggregates are ideal for controlled studies of the mechanics of individual germ layers because of the homogeneity of the cell type and the simple spherical geometry. Furthermore, the numerous molecular tools and transgenic lines already developed for this model organism can be applied to these aggregates, allowing us to characterize the contributions of cell cortex tension and cell adhesion to the mechanical properties of the zebrafish germ layers.

Microstructured Nickel-Titanium Thin Film Leaflets for Hybrid Tissue Engineered Heart Valves Fabricated by Magnetron Sputter Deposition.

PubMed

Loger, K; Engel, A; Haupt, J; Lima de Miranda, R; Lutter, G; Quandt, E

2016-03-01

Heart valves are constantly exposed to high dynamic loading and are prone to degeneration. Therefore, it is a challenge to develop a durable heart valve substitute. A promising approach in heart valve engineering is the development of hybrid scaffolds which are composed of a mechanically strong inorganic mesh enclosed by valvular tissue. In order to engineer an efficient, durable and very thin heart valve for transcatheter implantations, we developed a fabrication process for microstructured heart valve leaflets made from a nickel-titanium (NiTi) thin film shape memory alloy. To examine the capability of microstructured NiTi thin film as a matrix scaffold for tissue engineered hybrid heart valves, leaflets were successfully seeded with smooth muscle cells (SMCs). In vitro pulsatile hydrodynamic testing of the NiTi thin film valve leaflets demonstrated that the SMC layer significantly improved the diastolic sufficiency of the microstructured leaflets, without affecting the systolic efficiency. Compared to an established porcine reference valve model, magnetron sputtered NiTi thin film material demonstrated its suitability for hybrid tissue engineered heart valves.

Unit cell-based computer-aided manufacturing system for tissue engineering.

PubMed

Kang, Hyun-Wook; Park, Jeong Hun; Kang, Tae-Yun; Seol, Young-Joon; Cho, Dong-Woo

2012-03-01

Scaffolds play an important role in the regeneration of artificial tissues or organs. A scaffold is a porous structure with a micro-scale inner architecture in the range of several to several hundreds of micrometers. Therefore, computer-aided construction of scaffolds should provide sophisticated functionality for porous structure design and a tool path generation strategy that can achieve micro-scale architecture. In this study, a new unit cell-based computer-aided manufacturing (CAM) system was developed for the automated design and fabrication of a porous structure with micro-scale inner architecture that can be applied to composite tissue regeneration. The CAM system was developed by first defining a data structure for the computing process of a unit cell representing a single pore structure. Next, an algorithm and software were developed and applied to construct porous structures with a single or multiple pore design using solid freeform fabrication technology and a 3D tooth/spine computer-aided design model. We showed that this system is quite feasible for the design and fabrication of a scaffold for tissue engineering.

The biomaterials conundrum in tissue engineering.

PubMed

Williams, David F

2014-04-01

The development of biomaterials for use in tissue engineering processes has not so far followed a scientifically valid pathway; there have been no properly constituted specifications for these biomaterials, whose choice has often been dictated by the perceived need to comply with prior FDA approval for use of the materials in nontissue engineering applications. This short essay discusses the difficulties that have resulted in this approach and provides both conceptual and practical solutions for the future, based on sound principles of biocompatibility and the need to use tissue engineering templates that replicate the niche of the target cells.

Prospects of the development of the laser medical machinery for ensuring of progress of medical technologies

NASA Astrophysics Data System (ADS)

Litvin, Grigory D.; Vibornov, S. I.; Jakimenko, A. P.

1990-09-01

Medicine, arid surry in prticu1r, ha'vE rather visib1e and fixed objects and tasks On the hc1e they incILId diagnosis of thE? patological process, division of the tissues, control of tissue mtabo1ism. Each component of mdica1 practice contains in different aspects these general basic Itments EvEn now Iasr technology gives physicians thee opportunity to gain some benefit, in recognizing and measuring living obJects, modulation of metabol ism coagulation and vapor-ation of tissue water

Proposal of a punch biopsy protocol as a pre-requisite for the establishment of a tissue bank from resected esophageal tumors.

PubMed

Bonavina, Luigi; Laface, Letizia; Picozzi, Stefano; Nencioni, Marco; Siboni, Stefano; Bona, Davide; Sironi, Andrea; Sorba, Francesca; Clemente, Claudio

2010-09-01

With the development of tissue banking, a need for homogeneous methods of collection, processing, and storage of tissue has emerged. We describe the implementation of a biological bank in a high-volume, tertiary care University referral center for esophageal cancer surgery. We also propose an original punch biopsy technique of the surgical specimen. The method proved to be simple, reproducible, and not expensive. Unified standards for specimen collection are necessary to improve results of specimen-based diagnostic testing and research in surgical oncology.

RhBMP-2 loaded 3D-printed mesoporous silica/calcium phosphate cement porous scaffolds with enhanced vascularization and osteogenesis properties

NASA Astrophysics Data System (ADS)

Li, Cuidi; Jiang, Chuan; Deng, Yuan; Li, Tao; Li, Ning; Peng, Mingzheng; Wang, Jinwu

2017-01-01

A major limitation in the development of effective scaffolds for bone regeneration has been the limited vascularization of the regenerating tissue. Here, we propose the development of a novel calcium phosphate cement (CPC)-based scaffold combining the properties of mesoporous silica (MS) with recombinant human bone morphogenic protein-2 (rhBMP-2) to facilitate vascularization and osteogenesis. Specifically, the development of a custom MS/CPC paste allowed the three-dimensional (3D) printing of scaffolds with a defined macroporous structure and optimized silicon (Si) ions release profile to promote the ingrowth of vascular tissue at an early stage after implantation in support of tissue viability and osteogenesis. In addition, the scaffold microstructure allowed the prolonged release of rhBMP-2, which in turn significantly stimulated the osteogenesis of human bone marrow stromal cells in vitro and of bone regeneration in vivo as shown in a rabbit femur defect repair model. Thus, the combination MS/CPC/rhBMP-2 scaffolds might provide a solution to issues of tissue necrosis during the regeneration process and therefore might be able to be readily developed into a useful tool for bone repair in the clinic.

A biocompatible tissue scaffold produced by supercritical fluid processing for cartilage tissue engineering.

PubMed

Kim, Su Hee; Jung, Youngmee; Kim, Soo Hyun

2013-03-01

Supercritical fluids are used in various industrial fields, such as the food and medical industries, because they have beneficial physical and chemical properties and are also nonflammable and inexpensive. In particular, supercritical carbon dioxide (ScCO(2)) is attractive due to its mild critical temperature, pressure values, and nontoxicity. Poly(L-lactide-co-ɛ-caprolactone) (PLCL), which is a biocompatible, biodegradable, and very elastic polymer, has been used in cartilage tissue engineering. However, organic solvents, such as chloroform or dichloromethane, are usually used for the fabrication of a PLCL scaffold through conventional methods. This leads to a cytotoxic effect and long processing time for removing solvents. To alleviate these problems, supercritical fluid processing is introduced here. In this study, we fabricated a mechano-active PLCL scaffold by supercritical fluid processing for cartilage tissue engineering, and we compared it with a scaffold made by a conventional solvent-casting method in terms of physical and biological performance. Also, to examine the optimum condition for preparing scaffolds with ScCO(2), we investigated the effects of pressure, temperature, and the depressurization rate on PLCL foaming. The PLCL scaffolds produced by supercritical fluid processing had a homogeneously interconnected porous structure, and they exhibited a narrow pore size distribution. Also, there was no cytotoxicity of the scaffolds made with ScCO(2) compared to the scaffolds made by the solvent-pressing method. The scaffolds were seeded with chondrocytes, and they were subcutaneously implanted into nude mice for up to 4 weeks. In vivo accumulation of extracellular matrix of cell-scaffold constructs demonstrated that the PLCL scaffold made with ScCO(2) formed a mature and well-developed cartilaginous tissue compared to the PLCL scaffold formed by solvent pressing. Consequently, these results indicated that the PLCL scaffolds made by supercritical fluid processing offer well-interconnected and nontoxic substrates for cell growth, avoiding problems associated with a solvent residue. This suggests that these elastic PLCL scaffolds formed by supercritical fluid processing could be used for cartilage tissue engineering.

21 CFR 876.5885 - Tissue culture media for human ex vivo tissue and cell culture processing applications.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Tissue culture media for human ex vivo tissue and... DEVICES Therapeutic Devices § 876.5885 Tissue culture media for human ex vivo tissue and cell culture processing applications. (a) Identification. Tissue culture media for human ex vivo tissue and cell culture...

21 CFR 876.5885 - Tissue culture media for human ex vivo tissue and cell culture processing applications.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Tissue culture media for human ex vivo tissue and... DEVICES Therapeutic Devices § 876.5885 Tissue culture media for human ex vivo tissue and cell culture processing applications. (a) Identification. Tissue culture media for human ex vivo tissue and cell culture...

21 CFR 876.5885 - Tissue culture media for human ex vivo tissue and cell culture processing applications.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Tissue culture media for human ex vivo tissue and... DEVICES Therapeutic Devices § 876.5885 Tissue culture media for human ex vivo tissue and cell culture processing applications. (a) Identification. Tissue culture media for human ex vivo tissue and cell culture...

The bHLH transcription factor Hand is regulated by Alk in the Drosophila embryonic gut

DOE Office of Scientific and Technical Information (OSTI.GOV)

Varshney, Gaurav K.; Palmer, Ruth H.

2006-12-29

During embryonic development the midgut visceral muscle is formed by fusion of cells within the visceral mesoderm, a process initiated by the specification of a specialised cell type, the founder cell, within this tissue. Activation of the receptor tyrosine kinase Anaplastic lymphoma kinase (Alk) in the developing visceral muscle of Drosophila melanogaster initiates a signal transduction pathway required for muscle fusion. In this paper, we have investigated downstream components which are regulated by this novel signalling pathway. Here we show that Alk-mediated signal transduction drives the expression of the bHLH transcription factor Hand in vivo. Loss of Alk function resultsmore » in a complete lack of Hand expression in this tissue, whereas Alk gain of function results in an expansion of Hand expression. Finally, we have investigated the process of muscle fusion in the gut of Hand mutant animals and can find no obvious defects in this process, suggesting that Hand is not critical for visceral muscle fusion per se.« less

Fabrication of scaffolds in tissue engineering: A review

NASA Astrophysics Data System (ADS)

Zhao, Peng; Gu, Haibing; Mi, Haoyang; Rao, Chengchen; Fu, Jianzhong; Turng, Lih-sheng

2018-03-01

Tissue engineering (TE) is an integrated discipline that involves engineering and natural science in the development of biological materials to replace, repair, and improve the function of diseased or missing tissues. Traditional medical and surgical treatments have been reported to have side effects on patients caused by organ necrosis and tissue loss. However, engineered tissues and organs provide a new way to cure specific diseases. Scaffold fabrication is an important step in the TE process. This paper summarizes and reviews the widely used scaffold fabrication methods, including conventional methods, electrospinning, three-dimensional printing, and a combination of molding techniques. Furthermore, the differences among the properties of tissues, such as pore size and distribution, porosity, structure, and mechanical properties, are elucidated and critically reviewed. Some studies that combine two or more methods are also reviewed. Finally, this paper provides some guidance and suggestions for the future of scaffold fabrication.

Functional Attachment of Soft Tissues to Bone: Development, Healing, and Tissue Engineering

PubMed Central

Lu, Helen H.; Thomopoulos, Stavros

2014-01-01

Connective tissues such as tendons or ligaments attach to bone across a multitissue interface with spatial gradients in composition, structure, and mechanical properties. These gradients minimize stress concentrations and mediate load transfer between the soft and hard tissues. Given the high incidence of tendon and ligament injuries and the lack of integrative solutions for their repair, interface regeneration remains a significant clinical challenge. This review begins with a description of the developmental processes and the resultant structure-function relationships that translate into the functional grading necessary for stress transfer between soft tissue and bone. It then discusses the interface healing response, with a focus on the influence of mechanical loading and the role of cell-cell interactions. The review continues with a description of current efforts in interface tissue engineering, highlighting key strategies for the regeneration of the soft tissue–to-bone interface, and concludes with a summary of challenges and future directions. PMID:23642244

Steady State Fluorescence Spectroscopy for Medical Diagnosis

NASA Astrophysics Data System (ADS)

Mahadevan-Jansen, Anita; Gebhart, Steven C.

Light can react with tissue in different ways and provide information for identifying the physiological state of tissue or detecting the presence of disease. The light used to probe tissue does so in a non-intrusive manner and typically uses very low levels of light far below the requirements for therapeutic applications. The use of fiber optics simplifies the delivery and collection of this light in a minimally invasive manner. Since tissue response is virtually instantaneous, the results are obtained in real-time and the use of data processing techniques and multi-variate statistical analysis allows for automated detection and therefore provides an objective estimation of the tissue state. These then form the fundamental basis for the application of optical techniques for the detection of tissue physiology as well as pathology. These distinct advantages have encouraged many researchers to pursue the development of the different optical interactions for biological and medical detection.

Microfabricated tissues for investigating traction forces involved in cell migration and tissue morphogenesis

PubMed Central

Nerger, Bryan A.; Siedlik, Michael J.; Nelson, Celeste M.

2016-01-01

Cell-generated forces drive an array of biological processes ranging from wound healing to tumor metastasis. Whereas experimental techniques such as traction force microscopy are capable of quantifying traction forces in multidimensional systems, the physical mechanisms by which these forces induce changes in tissue form remain to be elucidated. Understanding these mechanisms will ultimately require techniques that are capable of quantifying traction forces with high precision and accuracy in vivo or in systems that recapitulate in vivo conditions, such as microfabricated tissues and engineered substrata. To that end, here we review the fundamentals of traction forces, their quantification, and the use of microfabricated tissues designed to study these forces during cell migration and tissue morphogenesis. We emphasize the differences between traction forces in two- and three-dimensional systems, and highlight recently developed techniques for quantifying traction forces. PMID:28008471

Spatially Different Tissue-Scale Diffusivity Shapes ANGUSTIFOLIA3 Gradient in Growing Leaves.

PubMed

Kawade, Kensuke; Tanimoto, Hirokazu; Horiguchi, Gorou; Tsukaya, Hirokazu

2017-09-05

The spatial gradient of signaling molecules is pivotal for establishing developmental patterns of multicellular organisms. It has long been proposed that these gradients could arise from the pure diffusion process of signaling molecules between cells, but whether this simplest mechanism establishes the formation of the tissue-scale gradient remains unclear. Plasmodesmata are unique channel structures in plants that connect neighboring cells for molecular transport. In this study, we measured cellular- and tissue-scale kinetics of molecular transport through plasmodesmata in Arabidopsis thaliana developing leaf primordia by fluorescence recovery assays. These trans-scale measurements revealed biophysical properties of diffusive molecular transport through plasmodesmata and revealed that the tissue-scale diffusivity, but not the cellular-scale diffusivity, is spatially different along the leaf proximal-to-distal axis. We found that the gradient in cell size along the developmental axis underlies this spatially different tissue-scale diffusivity. We then asked how this diffusion-based framework functions in establishing a signaling gradient of endogenous molecules. ANGUSTIFOLIA3 (AN3) is a transcriptional co-activator, and as we have shown here, it forms a long-range signaling gradient along the leaf proximal-to-distal axis to determine a cell-proliferation domain. By genetically engineering AN3 mobility, we assessed each contribution of cell-to-cell movement and tissue growth to the distribution of the AN3 gradient. We constructed a diffusion-based theoretical model using these quantitative data to analyze the AN3 gradient formation and demonstrated that it could be achieved solely by the diffusive molecular transport in a growing tissue. Our results indicate that the spatially different tissue-scale diffusivity is a core mechanism for AN3 gradient formation. This provides evidence that the pure diffusion process establishes the formation of the long-range signaling gradient in leaf development. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Flexible automation of cell culture and tissue engineering tasks.

PubMed

Knoll, Alois; Scherer, Torsten; Poggendorf, Iris; Lütkemeyer, Dirk; Lehmann, Jürgen

2004-01-01

Until now, the predominant use cases of industrial robots have been routine handling tasks in the automotive industry. In biotechnology and tissue engineering, in contrast, only very few tasks have been automated with robots. New developments in robot platform and robot sensor technology, however, make it possible to automate plants that largely depend on human interaction with the production process, e.g., for material and cell culture fluid handling, transportation, operation of equipment, and maintenance. In this paper we present a robot system that lends itself to automating routine tasks in biotechnology but also has the potential to automate other production facilities that are similar in process structure. After motivating the design goals, we describe the system and its operation, illustrate sample runs, and give an assessment of the advantages. We conclude this paper by giving an outlook on possible further developments.

Three-dimensional reconstruction of teeth and jaws based on segmentation of CT images using watershed transformation.

PubMed

Naumovich, S S; Naumovich, S A; Goncharenko, V G

2015-01-01

The objective of the present study was the development and clinical testing of a three-dimensional (3D) reconstruction method of teeth and a bone tissue of the jaw on the basis of CT images of the maxillofacial region. 3D reconstruction was performed using the specially designed original software based on watershed transformation. Computed tomograms in digital imaging and communications in medicine format obtained on multispiral CT and CBCT scanners were used for creation of 3D models of teeth and the jaws. The processing algorithm is realized in the stepwise threshold image segmentation with the placement of markers in the mode of a multiplanar projection in areas relating to the teeth and a bone tissue. The developed software initially creates coarse 3D models of the entire dentition and the jaw. Then, certain procedures specify the model of the jaw and cut the dentition into separate teeth. The proper selection of the segmentation threshold is very important for CBCT images having a low contrast and high noise level. The developed semi-automatic algorithm of multispiral and cone beam computed tomogram processing allows 3D models of teeth to be created separating them from a bone tissue of the jaws. The software is easy to install in a dentist's workplace, has an intuitive interface and takes little time in processing. The obtained 3D models can be used for solving a wide range of scientific and clinical tasks.

An overview of cartilage tissue engineering.

PubMed

Kim, H W; Han, C D

2000-12-01

Articular cartilage regeneration refers to the formation of new tissue that is indistinguishable from the native articular cartilage with respect to zonal organization, biochemical composition, and mechanical properties. Due to a limited capacity to repair cartilage, scar tissue frequently has a poorly organized structure and lacks the functional characteristics of normal cartilage. The degree of success to date achieved using a purely cell- or biological-based approach has been modest. Potentially the development of a hybrid strategy, whereby, chondrocytes or chondrogenic stem cells are combined with a matrix, making cartilage in vitro, which is then subsequently transplanted, offers a route towards a new successful treatment modality. The success of this approach depends upon the material being biocompatible, processable into a suitable three-dimensional structure and eventually biodegradable without harmful effects. In addition, the material should have a sufficient porosity to facilitate high cell loading and tissue ingrowth, and it should be able to support cell proliferation, differentiation, and function. The cell-polymer-bioreactor system provides a basis for studying the structural and functional properties of the cartilaginous matrix during its development, because tissue concentrations of glycosaminoglycan and collagen can be modulated by altering the conditions of tissue cultivation.

Segmentation of tumor and edema along with healthy tissues of brain using wavelets and neural networks.

PubMed

Demirhan, Ayşe; Toru, Mustafa; Guler, Inan

2015-07-01

Robust brain magnetic resonance (MR) segmentation algorithms are critical to analyze tissues and diagnose tumor and edema in a quantitative way. In this study, we present a new tissue segmentation algorithm that segments brain MR images into tumor, edema, white matter (WM), gray matter (GM), and cerebrospinal fluid (CSF). The detection of the healthy tissues is performed simultaneously with the diseased tissues because examining the change caused by the spread of tumor and edema on healthy tissues is very important for treatment planning. We used T1, T2, and FLAIR MR images of 20 subjects suffering from glial tumor. We developed an algorithm for stripping the skull before the segmentation process. The segmentation is performed using self-organizing map (SOM) that is trained with unsupervised learning algorithm and fine-tuned with learning vector quantization (LVQ). Unlike other studies, we developed an algorithm for clustering the SOM instead of using an additional network. Input feature vector is constructed with the features obtained from stationary wavelet transform (SWT) coefficients. The results showed that average dice similarity indexes are 91% for WM, 87% for GM, 96% for CSF, 61% for tumor, and 77% for edema.

World Endometriosis Research Foundation Endometriosis Phenome and Biobanking Harmonisation Project: IV. Tissue collection, processing, and storage in endometriosis research

PubMed Central

Fassbender, Amelie; Rahmioglu, Nilufer; Vitonis, Allison F.; Viganò, Paola; Giudice, Linda C.; D’Hooghe, Thomas M.; Hummelshoj, Lone; Adamson, G. David; Becker, Christian M.; Missmer, Stacey A.; Zondervan, Krina T.; Adamson, G.D.; Allaire, C.; Anchan, R.; Becker, C.M.; Bedaiwy, M.A.; Buck Louis, G.M.; Calhaz-Jorge, C.; Chwalisz, K.; D'Hooghe, T.M.; Fassbender, A.; Faustmann, T.; Fazleabas, A.T.; Flores, I.; Forman, A.; Fraser, I.; Giudice, L.C.; Gotte, M.; Gregersen, P.; Guo, S.-W.; Harada, T.; Hartwell, D.; Horne, A.W.; Hull, M.L.; Hummelshoj, L.; Ibrahim, M.G.; Kiesel, L.; Laufer, M.R.; Machens, K.; Mechsner, S.; Missmer, S.A.; Montgomery, G.W.; Nap, A.; Nyegaard, M.; Osteen, K.G.; Petta, C.A.; Rahmioglu, N.; Renner, S.P.; Riedlinger, J.; Roehrich, S.; Rogers, P.A.; Rombauts, L.; Salumets, A.; Saridogan, E.; Seckin, T.; Stratton, P.; Sharpe-Timms, K.L.; Tworoger, S.; Vigano, P.; Vincent, K.; Vitonis, A.F.; Wienhues-Thelen, U.-H.; Yeung, P.P.; Yong, P.; Zondervan, K.T.

2014-01-01

Objective To harmonize standard operating procedures (SOPs) and standardize the recording of associated data for collection, processing, and storage of human tissues relevant to endometriosis. Design An international collaboration involving 34 clinical/academic centers and three industry collaborators from 16 countries on five continents. Setting In 2013, two workshops were conducted followed by global consultation, bringing together 54 leaders in endometriosis research and sample processing from around the world. Patient(s) None. Intervention(s) Consensus SOPs were based on: 1) systematic comparison of SOPs from 24 global centers collecting tissue samples from women with and without endometriosis on a medium or large scale (publication on >100 cases); 2) literature evidence where available, or consultation with laboratory experts otherwise; and 3) several global consultation rounds. Main Outcome Measure(s) Standard recommended and minimum required SOPs for tissue collection, processing, and storage in endometriosis research. Result(s) We developed “recommended standard” and “minimum required” SOPs for the collection, processing, and storage of ectopic and eutopic endometrium, peritoneum, and myometrium, and a biospecimen data collection form necessary for interpretation of sample-derived results. Conclusion(s) The EPHect SOPs allow endometriosis research centers to decrease variability in tissue-based results, facilitating between-center comparisons and collaborations. The procedures are also relevant to research into other gynecologic conditions involving endometrium, myometrium, and peritoneum. The consensus SOPs are based on the best available evidence; areas with limited evidence are identified as requiring further pilot studies. The SOPs will be reviewed based on investigator feedback and through systematic triannual follow-up. Updated versions will be made available at: http://endometriosisfoundation.org/ephect. PMID:25256928

Linking the Primary Cilium to Cell Migration in Tissue Repair and Brain Development

PubMed Central

Veland, Iben Rønn; Lindbæk, Louise; Christensen, Søren Tvorup

2014-01-01

Primary cilia are unique sensory organelles that coordinate cellular signaling networks in vertebrates. Inevitably, defects in the formation or function of primary cilia lead to imbalanced regulation of cellular processes that causes multisystemic disorders and diseases, commonly known as ciliopathies. Mounting evidence has demonstrated that primary cilia coordinate multiple activities that are required for cell migration, which, when they are aberrantly regulated, lead to defects in organogenesis and tissue repair, as well as metastasis of tumors. Here, we present an overview on how primary cilia may contribute to the regulation of the cellular signaling pathways that control cyclic processes in directional cell migration. PMID:26955067

Photo-induced processes in collagen-hypericin system revealed by fluorescence spectroscopy and multiphoton microscopy

PubMed Central

Hovhannisyan, V.; Guo, H. W.; Hovhannisyan, A.; Ghukasyan, V.; Buryakina, T.; Chen, Y. F.; Dong, C. Y.

2014-01-01

Collagen is the main structural protein and the key determinant of mechanical and functional properties of tissues and organs. Proper balance between synthesis and degradation of collagen molecules is critical for maintaining normal physiological functions. In addition, collagen influences tumor development and drug delivery, which makes it a potential cancer therapy target. Using second harmonic generation, two-photon excited fluorescence microscopy, and spectrofluorimetry, we show that the natural pigment hypericin induces photosensitized destruction of collagen-based tissues. We demonstrate that hypericin–mediated processes in collagen fibers are irreversible and may be used for the treatment of cancer and collagen-related disorders. PMID:24877000

Photo-induced processes in collagen-hypericin system revealed by fluorescence spectroscopy and multiphoton microscopy.

PubMed

Hovhannisyan, V; Guo, H W; Hovhannisyan, A; Ghukasyan, V; Buryakina, T; Chen, Y F; Dong, C Y

2014-05-01

Collagen is the main structural protein and the key determinant of mechanical and functional properties of tissues and organs. Proper balance between synthesis and degradation of collagen molecules is critical for maintaining normal physiological functions. In addition, collagen influences tumor development and drug delivery, which makes it a potential cancer therapy target. Using second harmonic generation, two-photon excited fluorescence microscopy, and spectrofluorimetry, we show that the natural pigment hypericin induces photosensitized destruction of collagen-based tissues. We demonstrate that hypericin-mediated processes in collagen fibers are irreversible and may be used for the treatment of cancer and collagen-related disorders.

Nanoengineered surfaces for focal adhesion guidance trigger mesenchymal stem cell self-organization and tenogenesis.

PubMed

Iannone, Maria; Ventre, Maurizio; Formisano, Lucia; Casalino, Laura; Patriarca, Eduardo J; Netti, Paolo A

2015-03-11

The initial conditions for morphogenesis trigger a cascade of events that ultimately dictate structure and functions of tissues and organs. Here we report that surface nanopatterning can control the initial assembly of focal adhesions, hence guiding human mesenchymal stem cells (hMSCs) through the process of self-organization and differentiation. This process self-sustains, leading to the development of macroscopic tissues with molecular profiles and microarchitecture reminiscent of embryonic tendons. Therefore, material surfaces can be in principle engineered to set off the hMSC program toward tissuegenesis in a deterministic manner by providing adequate sets of initial environmental conditions.

Three Dimensional Projection Environment for Molecular Design and Surgical Simulation

DTIC Science & Technology

2011-08-01

bypasses the cumbersome meshing process . The deformation model is only comprised of mass nodes, which are generated by sampling the object volume before...force should minimize the penetration volume, the haptic feedback force is derived directly. Additionally, a post- processing technique is developed to...render distinct physi-cal tissue properties across different interaction areas. The proposed approach does not require any pre- processing and is

Microsurgery Simulator of Cerebral Aneurysm Clipping with Interactive Cerebral Deformation Featuring a Virtual Arachnoid.

PubMed

Shono, Naoyuki; Kin, Taichi; Nomura, Seiji; Miyawaki, Satoru; Saito, Toki; Imai, Hideaki; Nakatomi, Hirofumi; Oyama, Hiroshi; Saito, Nobuhito

2018-05-01

A virtual reality simulator for aneurysmal clipping surgery is an attractive research target for neurosurgeons. Brain deformation is one of the most important functionalities necessary for an accurate clipping simulator and is vastly affected by the status of the supporting tissue, such as the arachnoid membrane. However, no virtual reality simulator implementing the supporting tissue of the brain has yet been developed. To develop a virtual reality clipping simulator possessing interactive brain deforming capability closely dependent on arachnoid dissection and apply it to clinical cases. Three-dimensional computer graphics models of cerebral tissue and surrounding structures were extracted from medical images. We developed a new method for modifiable cerebral tissue complex deformation by incorporating a nonmedical image-derived virtual arachnoid/trabecula in a process called multitissue integrated interactive deformation (MTIID). MTIID made it possible for cerebral tissue complexes to selectively deform at the site of dissection. Simulations for 8 cases of actual clipping surgery were performed before surgery and evaluated for their usefulness in surgical approach planning. Preoperatively, each operative field was precisely reproduced and visualized with the virtual brain retraction defined by users. The clear visualization of the optimal approach to treating the aneurysm via an appropriate arachnoid incision was possible with MTIID. A virtual clipping simulator mainly focusing on supporting tissues and less on physical properties seemed to be useful in the surgical simulation of cerebral aneurysm clipping. To our knowledge, this article is the first to report brain deformation based on supporting tissues.

Using multimodal imaging techniques to monitor limb ischemia: a rapid noninvasive method for assessing extremity wounds

NASA Astrophysics Data System (ADS)

Luthra, Rajiv; Caruso, Joseph D.; Radowsky, Jason S.; Rodriguez, Maricela; Forsberg, Jonathan; Elster, Eric A.; Crane, Nicole J.

2013-03-01

Over 70% of military casualties resulting from the current conflicts sustain major extremity injuries. Of these the majority are caused by blasts from improvised explosive devices. The resulting injuries include traumatic amputations, open fractures, crush injuries, and acute vascular disruption. Critical tissue ischemia—the point at which ischemic tissues lose the capacity to recover—is therefore a major concern, as lack of blood flow to tissues rapidly leads to tissue deoxygenation and necrosis. If left undetected or unaddressed, a potentially salvageable limb may require more extensive debridement or, more commonly, amputation. Predicting wound outcome during the initial management of blast wounds remains a significant challenge, as wounds continue to "evolve" during the debridement process and our ability to assess wound viability remains subjectively based. Better means of identifying critical ischemia are needed. We developed a swine limb ischemia model in which two imaging modalities were combined to produce an objective and quantitative assessment of wound perfusion and tissue viability. By using 3 Charge-Coupled Device (3CCD) and Infrared (IR) cameras, both surface tissue oxygenation as well as overall limb perfusion could be depicted. We observed a change in mean 3CCD and IR values at peak ischemia and during reperfusion correlate well with clinically observed indicators for limb function and vitality. After correcting for baseline mean R-B values, the 3CCD values correlate with surface tissue oxygenation and the IR values with changes in perfusion. This study aims to not only increase fundamental understanding of the processes involved with limb ischemia and reperfusion, but also to develop tools to monitor overall limb perfusion and tissue oxygenation in a clinical setting. A rapid and objective diagnostic for extent of ischemic damage and overall limb viability could provide surgeons with a more accurate indication of tissue viability. This may help reducing the number of surgical interventions required, by aiding surgeons in identifying and demarcating areas of critical tissue ischemia, so that a more adequate debridement may be performed. This would have obvious benefits of reducing patient distress and decreasing both the overall recovery time and cost of rehabilitation.

Oxytocin receptor dynamics in the brain across development and species.

PubMed

Vaidyanathan, Radhika; Hammock, Elizabeth A D

2017-02-01

Oxytocin (OXT) signaling through the OXT receptor plays a significant role in a variety of physiological processes throughout the lifespan. OXT's effects depend on the tissue distribution of the receptor. This tissue specificity is dynamic and changes across development, and also varies with sex, experience, and species. The purpose of this review is to highlight these themes with examples from several life stages and several species. Important knowledge gaps will also be emphasized. Understanding the effective sites of action for OXT via its receptor will help refine hypotheses about the roles of this important neuropeptide in the experience-dependent development and expression of species-typical social behavior. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 143-157, 2017. © 2016 Wiley Periodicals, Inc.

Gap Junction Intercellular Communication: A Review of a Potential Platform to Modulate Craniofacial Tissue Engineering

PubMed Central

Rossello, Ricardo A.; Kohn, David H.

2009-01-01

Defects in craniofacial tissues, resulting from trauma, congenital abnormalities, oncologic resection or progressive deforming diseases, may result in aesthetic deformity, pain and reduced function. Restoring the structure, function and aesthetics of craniofacial tissues represents a substantial clinical problem in need of new solutions. More biologically-interactive biomaterials could potentially improve the treatment of craniofacial defects, and an understanding of developmental processes may help identify strategies and materials that can be used in tissue engineering. One such strategy that can potentially advance tissue engineering is cell–cell communication. Gap junction intercellular communication is the most direct way of achieving such signaling. Gap junction communication through connexin-mediated junctions, in particular connexin 43 (Cx43), plays a major role bone development. Given the important role of Cx43 in controlling development and differentiation, especially in bone cells, controlling the expression of Cx43 may provide control over cell-to-cell communication and may help overcome some of the challenges in craniofacial tissue engineering. Following a review of gap junctions in bone cells, the ability to enhance cell–cell communication and osteogenic differentiation via control of gap junctions is discussed, as is the potential utility of this approach in craniofacial tissue engineering. PMID:18481782

Using Electronic Noses to Detect Tumors During Neurosurgery

NASA Technical Reports Server (NTRS)

Homer, Margie L.; Ryan, Margaret A.; Lara, Liana M.; Kateb, Babak; Chen, Mike

2008-01-01

It has been proposed to develop special-purpose electronic noses and algorithms for processing the digitized outputs of the electronic noses for determining whether tissue exposed during neurosurgery is cancerous. At present, visual inspection by a surgeon is the only available intraoperative technique for detecting cancerous tissue. Implementation of the proposal would help to satisfy a desire, expressed by some neurosurgeons, for an intraoperative technique for determining whether all of a brain tumor has been removed. The electronic-nose technique could complement multimodal imaging techniques, which have also been proposed as means of detecting cancerous tissue. There are also other potential applications of the electronic-nose technique in general diagnosis of abnormal tissue. In preliminary experiments performed to assess the viability of the proposal, the problem of distinguishing between different types of cultured cells was substituted for the problem of distinguishing between normal and abnormal specimens of the same type of tissue. The figure presents data from one experiment, illustrating differences between patterns that could be used to distinguish between two types of cultured cancer cells. Further development can be expected to include studies directed toward answering questions concerning not only the possibility of distinguishing among various types of normal and abnormal tissue but also distinguishing between tissues of interest and other odorous substances that may be present in medical settings.

An Automatic Occlusion Device for Remote Control of Tumor Tissue Ischemia

PubMed Central

El-Dahdah, Hamid; Wang, Bei; He, Guanglong; Xu, Ronald X.

2015-01-01

We developed an automatic occlusion device for remote control of tumor tissue ischemia. The device consists of a flexible cannula encasing a shape memory alloy wire with its distal end connected to surgical suture. Regional tissue occlusion was tested on both the benchtop and the animal models. In the benchtop test, the occlusion device introduced quantitative and reproducible changes of blood flow in a tissue simulating phantom embedding a vessel simulator. In the animal test, the device generated a cyclic pattern of reversible ischemia in the right hinder leg tissue of a black male C57BL/6 mouse. We also developed a multimodal detector that integrates near infrared spectroscopy and electron paramagnetic resonance spectroscopy for continuous monitoring of tumor tissue oxygenation, blood content, and oxygen tension changes. The multimodal detector was tested on a cancer xenograft nude mouse undergoing reversible tumor ischemia. The automatic occlusion device and the multi-modal detector can be potentially integrated for closed-loop feedback control of tumor tissue ischemia. Such an integrated occlusion device may be used in multiple clinical applications such as regional hypoperfusion control in tumor resection surgeries and thermal ablation processes. In addition, the proposed occlusion device can also be used as a research tool to understand tumor oxygen transport and hemodynamic characteristics. PMID:20082532

Assessing diabetic foot ulcer development risk with hyperspectral tissue oximetry

NASA Astrophysics Data System (ADS)

Yudovsky, Dmitry; Nouvong, Aksone; Schomacker, Kevin; Pilon, Laurent

2011-02-01

Foot ulceration remains a serious health concern for diabetic patients and has a major impact on the cost of diabetes treatment. Early detection and preventive care, such as offloading or improved hygiene, can greatly reduce the risk of further complications. We aim to assess the use of hyperspectral tissue oximetry in predicting the risk of diabetic foot ulcer formation. Tissue oximetry measurements are performed during several visits with hyperspectral imaging of the feet in type 1 and 2 diabetes mellitus subjects that are at risk for foot ulceration. The data are retrospectively analyzed at 21 sites that ulcerated during the course of our study and an ulceration prediction index is developed. Then, an image processing algorithm based on this index is implemented. This algorithm is able to predict tissue at risk of ulceration with a sensitivity and specificity of 95 and 80%, respectively, for images taken, on average, 58 days before tissue damage is apparent to the naked eye. Receiver operating characteristic analysis is also performed to give a range of sensitivity/specificity values resulting in a Q-value of 89%.

From forest and agro-ecosystems to the microecosystems of the human body: what can landscape ecology tell us about tumor growth, metastasis, and treatment options?

PubMed Central

Daoust, Simon P; Fahrig, Lenore; Martin, Amanda E; Thomas, Frédéric

2013-01-01

Cancer is now understood to be a process that follows Darwinian evolution. Heterogeneous populations of cancerous cells that make up the tumor inhabit the tissue ‘microenvironment’, where ecological interactions analogous to predation and competition for resources drive the somatic evolution of cancer. The tumor microenvironment plays a crucial role in the tumor genesis, development, and metastasis processes, as it creates the microenvironmental selection forces that ultimately determine the cellular characteristics that result in the greatest fitness. Here, we explore and offer new insights into the spatial aspects of tumor–microenvironment interactions through the application of landscape ecology theory to tumor growth and metastasis within the tissue microhabitat. We argue that small tissue microhabitats in combination with the spatial distribution of resources within these habitats could be important selective forces driving tumor invasiveness. We also contend that the compositional and configurational heterogeneity of components in the tissue microhabitat do not only influence resource availability and functional connectivity but also play a crucial role in facilitating metastasis and may serve to explain, at least in part, tissue tropism in certain cancers. This novel work provides a compelling argument for the necessity of taking into account the structure of the tissue microhabitat when investigating tumor progression. PMID:23396712

From forest and agro-ecosystems to the microecosystems of the human body: what can landscape ecology tell us about tumor growth, metastasis, and treatment options?

PubMed

Daoust, Simon P; Fahrig, Lenore; Martin, Amanda E; Thomas, Frédéric

2013-01-01

Cancer is now understood to be a process that follows Darwinian evolution. Heterogeneous populations of cancerous cells that make up the tumor inhabit the tissue 'microenvironment', where ecological interactions analogous to predation and competition for resources drive the somatic evolution of cancer. The tumor microenvironment plays a crucial role in the tumor genesis, development, and metastasis processes, as it creates the microenvironmental selection forces that ultimately determine the cellular characteristics that result in the greatest fitness. Here, we explore and offer new insights into the spatial aspects of tumor-microenvironment interactions through the application of landscape ecology theory to tumor growth and metastasis within the tissue microhabitat. We argue that small tissue microhabitats in combination with the spatial distribution of resources within these habitats could be important selective forces driving tumor invasiveness. We also contend that the compositional and configurational heterogeneity of components in the tissue microhabitat do not only influence resource availability and functional connectivity but also play a crucial role in facilitating metastasis and may serve to explain, at least in part, tissue tropism in certain cancers. This novel work provides a compelling argument for the necessity of taking into account the structure of the tissue microhabitat when investigating tumor progression.

Robust cell tracking in epithelial tissues through identification of maximum common subgraphs.

PubMed

Kursawe, Jochen; Bardenet, Rémi; Zartman, Jeremiah J; Baker, Ruth E; Fletcher, Alexander G

2016-11-01

Tracking of cells in live-imaging microscopy videos of epithelial sheets is a powerful tool for investigating fundamental processes in embryonic development. Characterizing cell growth, proliferation, intercalation and apoptosis in epithelia helps us to understand how morphogenetic processes such as tissue invagination and extension are locally regulated and controlled. Accurate cell tracking requires correctly resolving cells entering or leaving the field of view between frames, cell neighbour exchanges, cell removals and cell divisions. However, current tracking methods for epithelial sheets are not robust to large morphogenetic deformations and require significant manual interventions. Here, we present a novel algorithm for epithelial cell tracking, exploiting the graph-theoretic concept of a 'maximum common subgraph' to track cells between frames of a video. Our algorithm does not require the adjustment of tissue-specific parameters, and scales in sub-quadratic time with tissue size. It does not rely on precise positional information, permitting large cell movements between frames and enabling tracking in datasets acquired at low temporal resolution due to experimental constraints such as phototoxicity. To demonstrate the method, we perform tracking on the Drosophila embryonic epidermis and compare cell-cell rearrangements to previous studies in other tissues. Our implementation is open source and generally applicable to epithelial tissues. © 2016 The Authors.

Controlled destruction and temperature distributions in biological tissues subjected to monoactive electrocoagulation.

PubMed

Erez, A; Shitzer, A

1980-02-01

An analysis of the temperature fields developed in a biological tissue undergoing a monoactive electrical coagulating process is presented, including thermal recovery following prolonged heating. The analysis is performed for the passage of alternating current and assumes a homogeneous and isotropic tissue model which is uniformly perfused by blood at arterial temperature. Solution for the one-dimensional spherical geometry is obtained by a Laplace transform and numerical integrations. Results obtained indicate the major role which blood perfusion plays in determining the effects of the coagulating process; tissue temperatures and depth of destruction are drastically reduced as blood perfusion increases. Metabolic heat generation rate is found to have negligible effects on tissue temperatures whereas electrode thermal inertia affects temperature levels appreciably. However, electrodes employed in practice would have a low thermal inertia which might be regarded as zero for all practical purposes. It is also found that the depth of tissue destruction is almost directly proportional to the electrical power and duration of application. To avoid excessively high temperatures and charring, it would be advantageous to reduce power and increase the time of application. Results of this study should be regarded as a first approximation to the rather complex phenomena associated with electrocoagulation. They may, nevertheless, serve as preliminary guidelines to practicing surgeons applying this technique.

Robust cell tracking in epithelial tissues through identification of maximum common subgraphs

PubMed Central

Bardenet, Rémi; Zartman, Jeremiah J.; Baker, Ruth E.

2016-01-01

Tracking of cells in live-imaging microscopy videos of epithelial sheets is a powerful tool for investigating fundamental processes in embryonic development. Characterizing cell growth, proliferation, intercalation and apoptosis in epithelia helps us to understand how morphogenetic processes such as tissue invagination and extension are locally regulated and controlled. Accurate cell tracking requires correctly resolving cells entering or leaving the field of view between frames, cell neighbour exchanges, cell removals and cell divisions. However, current tracking methods for epithelial sheets are not robust to large morphogenetic deformations and require significant manual interventions. Here, we present a novel algorithm for epithelial cell tracking, exploiting the graph-theoretic concept of a ‘maximum common subgraph’ to track cells between frames of a video. Our algorithm does not require the adjustment of tissue-specific parameters, and scales in sub-quadratic time with tissue size. It does not rely on precise positional information, permitting large cell movements between frames and enabling tracking in datasets acquired at low temporal resolution due to experimental constraints such as phototoxicity. To demonstrate the method, we perform tracking on the Drosophila embryonic epidermis and compare cell–cell rearrangements to previous studies in other tissues. Our implementation is open source and generally applicable to epithelial tissues. PMID:28334699

Transcriptional activity of TGFβ1 and its receptors genes in thyroid gland.

PubMed

Kajdaniuk, Dariusz; Marek, Anna; Marek, Bogdan; Mazurek, Urszula; Fila-Daniłow, Anna; Foltyn, Wanda; Morawiec-Szymonik, Elżbieta; Siemińśka, Lucyna; Nowak, Mariusz; Głogowska-Szeląg, Joanna; Niedziołka-Zielonka, Danuta; Seemann, Michał; Kos-Kudła, Beata

2016-01-01

Determination of gene-candidates' profile expression responsible for fibrosis, immunosuppression, angiogenesis, and neoplasia processes in the pathogenesis of thyroid gland disease. Sixty-three patients underwent thyroidectomy: 27 with non-toxic nodular goitre (NG), 22 with toxic nodular goitre (TNG), six with papillary cancer (PTC), and eight with Graves' disease (GD). In thyroid tissues, transcriptional activity of TGFbeta1 and its receptors TGFbetaRI, TGFbetaRII, and TGFbetaRIII genes were assessed using RT-qPCR (Reverse Transcriptase Quantitative Polymerase Chain Reaction). Molecular analysis was performed in tissues derived from GD and from the tumour centre (PTC, NG, TNG) and from peripheral parts of the removed lobe without histopathological lesions (tissue control). Control tissue for analysis performed in GD was an unchanged tissue derived from peripheral parts of the removed lobe of patients surgically treated for a single benign tumour. Strict regulation observed among transcriptional activity of TGFb1 and their receptor TGFbetaRI-III genes in control tissues is disturbed in all pathological tissues - it is completely disturbed in PTC and GD, and partially in NG and TNG. Additionally, higher transcriptional activity of TGFb1 gene in PTC in comparison with benign tissues (NG, GD) and lower expression of mRNA TGFbRII (than in TNG, GD) and mRNA TGFbetaRIII than in all studied benign tissues (NG, TNG, GD) suggests a pathogenetic importance of this cytokine and its receptors in PTC development. In GD tissue, higher transcriptional activity of TGFbetaRII and TGFbetaRIII genes as compared to other pathological tissues was observed, indicating a participation of the receptors in the pathomechanism of autoimmune thyroid disease (AITD). TGFbeta1 blood concentrations do not reflect pathological processes taking place in thyroid gland. (Endokrynol Pol 2016; 67 (4): 375-382).

Tissue-Specific Transcriptomic Profiling of Sorghum propinquum using a Rice Genome Array

PubMed Central

Zhang, Ting; Zhao, Xiuqin; Huang, Liyu; Liu, Xiaoyue; Zong, Ying; Zhu, Linghua; Yang, Daichang; Fu, Binying

2013-01-01

Sorghum (Sorghum bicolor) is one of the world's most important cereal crops. S. propinquum is a perennial wild relative of S. bicolor with well-developed rhizomes. Functional genomics analysis of S. propinquum, especially with respect to molecular mechanisms related to rhizome growth and development, can contribute to the development of more sustainable grain, forage, and bioenergy cropping systems. In this study, we used a whole rice genome oligonucleotide microarray to obtain tissue-specific gene expression profiles of S. propinquum with special emphasis on rhizome development. A total of 548 tissue-enriched genes were detected, including 31 and 114 unique genes that were expressed predominantly in the rhizome tips (RT) and internodes (RI), respectively. Further GO analysis indicated that the functions of these tissue-enriched genes corresponded to their characteristic biological processes. A few distinct cis-elements, including ABA-responsive RY repeat CATGCA, sugar-repressive TTATCC, and GA-responsive TAACAA, were found to be prevalent in RT-enriched genes, implying an important role in rhizome growth and development. Comprehensive comparative analysis of these rhizome-enriched genes and rhizome-specific genes previously identified in Oryza longistaminata and S. propinquum indicated that phytohormones, including ABA, GA, and SA, are key regulators of gene expression during rhizome development. Co-localization of rhizome-enriched genes with rhizome-related QTLs in rice and sorghum generated functional candidates for future cloning of genes associated with rhizome growth and development. PMID:23536906

Trends in the development of microfluidic cell biochips for in vitro hepatotoxicity.

PubMed

Baudoin, Régis; Corlu, Anne; Griscom, Laurent; Legallais, Cécile; Leclerc, Eric

2007-06-01

Current developments in the technological fields of liver tissue engineering, bioengineering, biomechanics, microfabrication and microfluidics have lead to highly complex and pertinent new tools called "cell biochips" for in vitro toxicology. The purpose of "cell biochips" is to mimic organ tissues in vitro in order to partially reduce the amount of in vivo testing. These "cell biochips" consist of microchambers containing engineered tissue and living cell cultures interconnected by a microfluidic network, which allows the control of microfluidic flows for dynamic cultures, by continuous feeding of nutrients to cultured cells and waste removal. Cell biochips also allow the control of physiological contact times of diluted molecules with the tissues and cells, for rapid testing of sample preparations or specific addressing. Cell biochips can be situated between in vitro and in vivo testing. These types of systems can enhance functionality of cells by mimicking the tissue architecture complexities when compared to in vitro analysis but at the same time present a more rapid and simple process when compared to in vivo testing procedures. In this paper, we first introduce the concepts of microfluidic and biochip systems based on recent progress in microfabrication techniques used to mimic liver tissue in vitro. This includes progress and understanding in biomaterials science (cell culture substrate), biomechanics (dynamic cultures conditions) and biology (tissue engineering). The development of new "cell biochips" for chronic toxicology analysis of engineered tissues can be achieved through the combination of these research domains. Combining these advanced research domains, we then present "cell biochips" that allow liver chronic toxicity analysis in vitro on engineered tissues. An extension of the "cell biochip" idea has also allowed "organ interactions on chip", which can be considered as a first step towards the replacement of animal testing using a combined liver/lung organ model.

Clinical, radiographic, and histological observation of a human immature permanent tooth with chronic apical abscess after revitalization treatment.

PubMed

Shimizu, Emi; Ricucci, Domenico; Albert, Jeffrey; Alobaid, Adel S; Gibbs, Jennifer L; Huang, George T-J; Lin, Louis M

2013-08-01

Revitalization procedures have been widely used for the treatment of immature permanent teeth with apical periodontitis. The treatment procedures appear to be capable of encouraging continued root development and thickening of the canal walls. The nature of tissues formed in the canal space and at the root apex after revitalization has been shown histologically in several animal studies; similar studies in humans were recently reported. A 9-year-old boy had a traumatic injury to his upper anterior teeth. Tooth #9 suffered a complicated crown fracture with a pulp exposure, which was restored with a composite resin. The tooth developed a chronic apical abscess. Revitalization procedures were performed on tooth #9 because it was an immature permanent tooth with an open apex and thin canal walls. Twenty-six months after revitalization, the tooth had a horizontal crown fracture at the cervical level and could not be restored. The tooth was extracted and processed for routine histological and immunohistochemical examination to identify the nature of tissues formed in the canal space. Clinically and radiographically, the revitalization of the present case was successful because of the absence of signs and symptoms and the resolution of periapical lesion as well as thickening of the canal walls and continued root development. The tissue formed in the canal was well-mineralized cementum- or bone-like tissue identified by routine histology and immunohistochemistry. No pulp-like tissue characterized by the presence of polarized odontoblast-like cells aligning dentin-like hard tissue was observed. The tissues formed in the canal of revitalized human tooth are similar to cementum- or bone-like tissue and fibrous connective tissue. Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Analyzing Structure and Function of Vascularization in Engineered Bone Tissue by Video-Rate Intravital Microscopy and 3D Image Processing.

PubMed

Pang, Yonggang; Tsigkou, Olga; Spencer, Joel A; Lin, Charles P; Neville, Craig; Grottkau, Brian

2015-10-01

Vascularization is a key challenge in tissue engineering. Three-dimensional structure and microcirculation are two fundamental parameters for evaluating vascularization. Microscopic techniques with cellular level resolution, fast continuous observation, and robust 3D postimage processing are essential for evaluation, but have not been applied previously because of technical difficulties. In this study, we report novel video-rate confocal microscopy and 3D postimage processing techniques to accomplish this goal. In an immune-deficient mouse model, vascularized bone tissue was successfully engineered using human bone marrow mesenchymal stem cells (hMSCs) and human umbilical vein endothelial cells (HUVECs) in a poly (D,L-lactide-co-glycolide) (PLGA) scaffold. Video-rate (30 FPS) intravital confocal microscopy was applied in vitro and in vivo to visualize the vascular structure in the engineered bone and the microcirculation of the blood cells. Postimage processing was applied to perform 3D image reconstruction, by analyzing microvascular networks and calculating blood cell viscosity. The 3D volume reconstructed images show that the hMSCs served as pericytes stabilizing the microvascular network formed by HUVECs. Using orthogonal imaging reconstruction and transparency adjustment, both the vessel structure and blood cells within the vessel lumen were visualized. Network length, network intersections, and intersection densities were successfully computed using our custom-developed software. Viscosity analysis of the blood cells provided functional evaluation of the microcirculation. These results show that by 8 weeks, the blood vessels in peripheral areas function quite similarly to the host vessels. However, the viscosity drops about fourfold where it is only 0.8 mm away from the host. In summary, we developed novel techniques combining intravital microscopy and 3D image processing to analyze the vascularization in engineered bone. These techniques have broad applicability for evaluating vascularization in other engineered tissues as well.

Development and Characterization of Mechanically Robust, 3D-Printable Photopolymers

NASA Astrophysics Data System (ADS)

Sycks, Dalton George

3D printing has seen an explosion of interest and growth in recent years, especially within the biomedical space. Prized for its efficiency, ability to produce complex geometries, and facile material processing, additive manufacturing is rapidly being used to create medical devices ranging from orthopedic implants to tissue scaffolds. However, 3D printing is currently limited to a select few material choices, especially when one considers soft tissue replacement or augmentation. To this end, my research focuses on developing material systems that are simultaneously 1) 3D printable, 2) biocompatible, and 3) mechanically robust with properties appropriate for soft-tissue replacement or augmentation applications. Two systems were developed toward this goal: an interpenetrating network (IPN) hydrogel consisting of covalently crosslinked poly (ethylene glycol) diacrylate (PEGDA) and ionically crosslinked brown sodium alginate, and semi-crystalline thiol-ene photopolymers containing spiroacetal molecules in the polymer main-chain backbone. In addition to successfully being incorporated into existing 3D printing systems (extrusion-deposition for the PEGDA-alginate hydrogel and digital light processing for the thiol-ene polymers) both systems exhibited biocompatibility and superior thermomechanical properties such as tensile modulus, failure strain, and toughness. This work offers two fully-developed, novel polymer platforms with outstanding performance; further, structure-property relationships are highlighted and discussed on a molecular and morphological level to provide material insights that are useful to researchers and engineers in the design of highly tuned and mechanically robust polymers.

A homeostatic-driven turnover remodelling constitutive model for healing in soft tissues

PubMed Central

Gasser, T. Christian; Bellomo, Facundo J.

2016-01-01

Remodelling of soft biological tissue is characterized by interacting biochemical and biomechanical events, which change the tissue's microstructure, and, consequently, its macroscopic mechanical properties. Remodelling is a well-defined stage of the healing process, and aims at recovering or repairing the injured extracellular matrix. Like other physiological processes, remodelling is thought to be driven by homeostasis, i.e. it tends to re-establish the properties of the uninjured tissue. However, homeostasis may never be reached, such that remodelling may also appear as a continuous pathological transformation of diseased tissues during aneurysm expansion, for example. A simple constitutive model for soft biological tissues that regards remodelling as homeostatic-driven turnover is developed. Specifically, the recoverable effective tissue damage, whose rate is the sum of a mechanical damage rate and a healing rate, serves as a scalar internal thermodynamic variable. In order to integrate the biochemical and biomechanical aspects of remodelling, the healing rate is, on the one hand, driven by mechanical stimuli, but, on the other hand, subjected to simple metabolic constraints. The proposed model is formulated in accordance with continuum damage mechanics within an open-system thermodynamics framework. The numerical implementation in an in-house finite-element code is described, particularized for Ogden hyperelasticity. Numerical examples illustrate the basic constitutive characteristics of the model and demonstrate its potential in representing aspects of remodelling of soft tissues. Simulation results are verified for their plausibility, but also validated against reported experimental data. PMID:27009177

A homeostatic-driven turnover remodelling constitutive model for healing in soft tissues.

PubMed

Comellas, Ester; Gasser, T Christian; Bellomo, Facundo J; Oller, Sergio

2016-03-01

Remodelling of soft biological tissue is characterized by interacting biochemical and biomechanical events, which change the tissue's microstructure, and, consequently, its macroscopic mechanical properties. Remodelling is a well-defined stage of the healing process, and aims at recovering or repairing the injured extracellular matrix. Like other physiological processes, remodelling is thought to be driven by homeostasis, i.e. it tends to re-establish the properties of the uninjured tissue. However, homeostasis may never be reached, such that remodelling may also appear as a continuous pathological transformation of diseased tissues during aneurysm expansion, for example. A simple constitutive model for soft biological tissues that regards remodelling as homeostatic-driven turnover is developed. Specifically, the recoverable effective tissue damage, whose rate is the sum of a mechanical damage rate and a healing rate, serves as a scalar internal thermodynamic variable. In order to integrate the biochemical and biomechanical aspects of remodelling, the healing rate is, on the one hand, driven by mechanical stimuli, but, on the other hand, subjected to simple metabolic constraints. The proposed model is formulated in accordance with continuum damage mechanics within an open-system thermodynamics framework. The numerical implementation in an in-house finite-element code is described, particularized for Ogden hyperelasticity. Numerical examples illustrate the basic constitutive characteristics of the model and demonstrate its potential in representing aspects of remodelling of soft tissues. Simulation results are verified for their plausibility, but also validated against reported experimental data. © 2016 The Author(s).

Developmental biology and tissue engineering.

PubMed

Marga, Francoise; Neagu, Adrian; Kosztin, Ioan; Forgacs, Gabor

2007-12-01

Morphogenesis implies the controlled spatial organization of cells that gives rise to tissues and organs in early embryonic development. While morphogenesis is under strict genetic control, the formation of specialized biological structures of specific shape hinges on physical processes. Tissue engineering (TE) aims at reproducing morphogenesis in the laboratory, i.e., in vitro, to fabricate replacement organs for regenerative medicine. The classical approach to generate tissues/organs is by seeding and expanding cells in appropriately shaped biocompatible scaffolds, in the hope that the maturation process will result in the desired structure. To accomplish this goal more naturally and efficiently, we set up and implemented a novel TE method that is based on principles of developmental biology and employs bioprinting, the automated delivery of cellular composites into a three-dimensional (3D) biocompatible environment. The novel technology relies on the concept of tissue liquidity according to which multicellular aggregates composed of adhesive and motile cells behave in analogy with liquids: in particular, they fuse. We emphasize the major role played by tissue fusion in the embryo and explain how the parameters (surface tension, viscosity) that govern tissue fusion can be used both experimentally and theoretically to control and simulate the self-assembly of cellular spheroids into 3D living structures. The experimentally observed postprinting shape evolution of tube- and sheet-like constructs is presented. Computer simulations, based on a liquid model, support the idea that tissue liquidity may provide a mechanism for in vitro organ building. Copyright 2008 Wiley-Liss, Inc.

3D printed optical phantoms and deep tissue imaging for in vivo applications including oral surgery

NASA Astrophysics Data System (ADS)

Bentz, Brian Z.; Costas, Alfonso; Gaind, Vaibhav; Garcia, Jose M.; Webb, Kevin J.

2017-03-01

Progress in developing optical imaging for biomedical applications requires customizable and often complex objects known as "phantoms" for testing, evaluation, and calibration. This work demonstrates that 3D printing is an ideal method for fabricating such objects, allowing intricate inhomogeneities to be placed at exact locations in complex or anatomically realistic geometries, a process that is difficult or impossible using molds. We show printed mouse phantoms we have fabricated for developing deep tissue fluorescence imaging methods, and measurements of both their optical and mechanical properties. Additionally, we present a printed phantom of the human mouth that we use to develop an artery localization method to assist in oral surgery.

Tissue Specific Dysregulated Protein Subnetworks in Type 2 Diabetic Bladder Urothelium and Detrusor Muscle*

PubMed Central

Tomechko, Sara E.; Liu, Guiming; Tao, Mingfang; Schlatzer, Daniela; Powell, C. Thomas; Gupta, Sanjay; Chance, Mark R.; Daneshgari, Firouz

2015-01-01

Diabetes mellitus is well known to cause bladder dysfunction; however, the molecular mechanisms governing this process and the effects on individual tissue elements within the bladder are poorly understood, particularly in type 2 diabetes. A shotgun proteomics approach was applied to identify proteins differentially expressed between type 2 diabetic (TallyHo) and control (SWR/J) mice in the bladder smooth muscle and urothelium, separately. We were able to identify 1760 nonredundant proteins from the detrusor smooth muscle and 3169 nonredundant proteins from urothelium. Pathway and network analysis of significantly dysregulated proteins was conducted to investigate the molecular processes associated with diabetes. This pinpointed ERK1/2 signaling as a key regulatory node in the diabetes-induced pathophysiology for both tissue types. The detrusor muscle samples showed diabetes-induced increased tissue remodeling-type events such as Actin Cytoskeleton Signaling and Signaling by Rho Family GTPases. The diabetic urothelium samples exhibited oxidative stress responses, as seen in the suppression of protein expression for key players in the NRF2-Mediated Oxidative Stress Response pathway. These results suggest that diabetes induced elevated inflammatory responses, oxidative stress, and tissue remodeling are involved in the development of tissue specific diabetic bladder dysfunctions. Validation of signaling dysregulation as a function of diabetes was performed using Western blotting. These data illustrated changes in ERK1/2 phosphorylation as a function of diabetes, with significant decreases in diabetes-associated phosphorylation in urothelium, but the opposite effect in detrusor muscle. These data highlight the importance of understanding tissue specific effects of disease process in understanding pathophysiology in complex disease and pave the way for future studies to better understand important molecular targets in reversing bladder dysfunction. PMID:25573746

Tissue specific dysregulated protein subnetworks in type 2 diabetic bladder urothelium and detrusor muscle.

PubMed

Tomechko, Sara E; Liu, Guiming; Tao, Mingfang; Schlatzer, Daniela; Powell, C Thomas; Gupta, Sanjay; Chance, Mark R; Daneshgari, Firouz

2015-03-01

Diabetes mellitus is well known to cause bladder dysfunction; however, the molecular mechanisms governing this process and the effects on individual tissue elements within the bladder are poorly understood, particularly in type 2 diabetes. A shotgun proteomics approach was applied to identify proteins differentially expressed between type 2 diabetic (TallyHo) and control (SWR/J) mice in the bladder smooth muscle and urothelium, separately. We were able to identify 1760 nonredundant proteins from the detrusor smooth muscle and 3169 nonredundant proteins from urothelium. Pathway and network analysis of significantly dysregulated proteins was conducted to investigate the molecular processes associated with diabetes. This pinpointed ERK1/2 signaling as a key regulatory node in the diabetes-induced pathophysiology for both tissue types. The detrusor muscle samples showed diabetes-induced increased tissue remodeling-type events such as Actin Cytoskeleton Signaling and Signaling by Rho Family GTPases. The diabetic urothelium samples exhibited oxidative stress responses, as seen in the suppression of protein expression for key players in the NRF2-Mediated Oxidative Stress Response pathway. These results suggest that diabetes induced elevated inflammatory responses, oxidative stress, and tissue remodeling are involved in the development of tissue specific diabetic bladder dysfunctions. Validation of signaling dysregulation as a function of diabetes was performed using Western blotting. These data illustrated changes in ERK1/2 phosphorylation as a function of diabetes, with significant decreases in diabetes-associated phosphorylation in urothelium, but the opposite effect in detrusor muscle. These data highlight the importance of understanding tissue specific effects of disease process in understanding pathophysiology in complex disease and pave the way for future studies to better understand important molecular targets in reversing bladder dysfunction. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Cell/tissue processing information system for regenerative medicine.

PubMed

Iwayama, Daisuke; Yamato, Masayuki; Tsubokura, Tetsuya; Takahashi, Minoru; Okano, Teruo

2016-11-01

When conducting clinical studies of regenerative medicine, compliance to good manufacturing practice (GMP) is mandatory, and thus much time is needed for manufacturing and quality management. It is therefore desired to introduce the manufacturing execution system (MES), which is being adopted by factories manufacturing pharmaceutical products. Meanwhile, in manufacturing human cell/tissue processing autologous products, it is necessary to protect patients' personal information, prevent patients from being identified and obtain information for cell/tissue identification. We therefore considered it difficult to adopt conventional MES to regenerative medicine-related clinical trials, and so developed novel software for production/quality management to be used in cell-processing centres (CPCs), conforming to GMP. Since this system satisfies the requirements of regulations in Japan and the USA for electronic records and electronic signatures (ER/ES), the use of ER/ES has been allowed, and the risk of contamination resulting from the use of recording paper has been eliminated, thanks to paperless operations within the CPC. Moreover, to reduce the risk of mix-up and cross-contamination due to contact during production, we developed a touchless input device with built-in radio frequency identification (RFID) reader-writer devices and optical sensors. The use of this system reduced the time to prepare and issue manufacturing instructions by 50% or more, compared to the conventional handwritten system. The system contributes to producing more large-scale production and to reducing production costs for cell and tissue products in regenerative medicine. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

Programmable Hydrogels for Cell Encapsulation and Neo-Tissue Growth to Enable Personalized Tissue Engineering.

PubMed

Bryant, Stephanie J; Vernerey, Franck J

2018-01-01

Biomimetic and biodegradable synthetic hydrogels are emerging as a promising platform for cell encapsulation and tissue engineering. Notably, synthetic-based hydrogels offer highly programmable macroscopic properties (e.g., mechanical, swelling and transport properties) and degradation profiles through control over several tunable parameters (e.g., the initial network structure, degradation kinetics and behavior, and polymer properties). One component to success is the ability to maintain structural integrity as the hydrogel transitions to neo-tissue. This seamless transition is complicated by the fact that cellular activity is highly variable among donors. Thus, computational models provide an important tool in tissue engineering due to their unique ability to explore the coupled processes of hydrogel degradation and neo-tissue growth across multiple length scales. In addition, such models provide new opportunities to develop predictive computational tools to overcome the challenges with designing hydrogels for different donors. In this report, programmable properties of synthetic-based hydrogels and their relation to the hydrogel's structural properties and their evolution with degradation are reviewed. This is followed by recent progress on the development of computational models that describe hydrogel degradation with neo-tissue growth when cells are encapsulated in a hydrogel. Finally, the potential for predictive models to enable patient-specific hydrogel designs for personalized tissue engineering is discussed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Surgical inflammatory stress: the embryo takes hold of the reins again

PubMed Central

2013-01-01

The surgical inflammatory response can be a type of high-grade acute stress response associated with an increasingly complex trophic functional system for using oxygen. This systemic neuro-immune-endocrine response seems to induce the re-expression of 2 extraembryonic-like functional axes, i.e. coelomic-amniotic and trophoblastic-yolk-sac-related, within injured tissues and organs, thus favoring their re-development. Accordingly, through the up-regulation of two systemic inflammatory phenotypes, i.e. neurogenic and immune-related, a gestational-like response using embryonic functions would be induced in the patient’s injured tissues and organs, which would therefore result in their repair. Here we establish a comparison between the pathophysiological mechanisms that are produced during the inflammatory response and the physiological mechanisms that are expressed during early embryonic development. In this way, surgical inflammation could be a high-grade stress response whose pathophysiological mechanisms would be based on the recapitulation of ontogenic and phylogenetic-related functions. Thus, the ultimate objective of surgical inflammation, as a gestational process, is creating new tissues/organs for repairing the injured ones. Since surgical inflammation and early embryonic development share common production mechanisms, the factors that hamper the wound healing reaction in surgical patients could be similar to those that impair the gestational process. PMID:23374964

Simulation of Healing Threshold in Strain-Induced Inflammation Through a Discrete Informatics Model.

PubMed

Ibrahim, Israr Bin M; Sarma O V, Sanjay; Pidaparti, Ramana M

2018-05-01

Respiratory diseases such as asthma and acute respiratory distress syndrome as well as acute lung injury involve inflammation at the cellular level. The inflammation process is very complex and is characterized by the emergence of cytokines along with other changes in cellular processes. Due to the complexity of the various constituents that makes up the inflammation dynamics, it is necessary to develop models that can complement experiments to fully understand inflammatory diseases. In this study, we developed a discrete informatics model based on cellular automata (CA) approach to investigate the influence of elastic field (stretch/strain) on the dynamics of inflammation and account for probabilistic adaptation based on statistical interpretation of existing experimental data. Our simulation model investigated the effects of low, medium, and high strain conditions on inflammation dynamics. Results suggest that the model is able to indicate the threshold of innate healing of tissue as a response to strain experienced by the tissue. When strain is under the threshold, the tissue is still capable of adapting its structure to heal the damaged part. However, there exists a strain threshold where healing capability breaks down. The results obtained demonstrate that the developed discrete informatics based CA model is capable of modeling and giving insights into inflammation dynamics parameters under various mechanical strain/stretch environments.

Bioinks for 3D bioprinting: an overview.

PubMed

Gungor-Ozkerim, P Selcan; Inci, Ilyas; Zhang, Yu Shrike; Khademhosseini, Ali; Dokmeci, Mehmet Remzi

2018-05-01

Bioprinting is an emerging technology with various applications in making functional tissue constructs to replace injured or diseased tissues. It is a relatively new approach that provides high reproducibility and precise control over the fabricated constructs in an automated manner, potentially enabling high-throughput production. During the bioprinting process, a solution of a biomaterial or a mixture of several biomaterials in the hydrogel form, usually encapsulating the desired cell types, termed the bioink, is used for creating tissue constructs. This bioink can be cross-linked or stabilized during or immediately after bioprinting to generate the final shape, structure, and architecture of the designed construct. Bioinks may be made from natural or synthetic biomaterials alone, or a combination of the two as hybrid materials. In certain cases, cell aggregates without any additional biomaterials can also be adopted for use as a bioink for bioprinting processes. An ideal bioink should possess proper mechanical, rheological, and biological properties of the target tissues, which are essential to ensure correct functionality of the bioprinted tissues and organs. In this review, we provide an in-depth discussion of the different bioinks currently employed for bioprinting, and outline some future perspectives in their further development.

Soft tissue deformation estimation by spatio-temporal Kalman filter finite element method.

PubMed

Yarahmadian, Mehran; Zhong, Yongmin; Gu, Chengfan; Shin, Jaehyun

2018-01-01

Soft tissue modeling plays an important role in the development of surgical training simulators as well as in robot-assisted minimally invasive surgeries. It has been known that while the traditional Finite Element Method (FEM) promises the accurate modeling of soft tissue deformation, it still suffers from a slow computational process. This paper presents a Kalman filter finite element method to model soft tissue deformation in real time without sacrificing the traditional FEM accuracy. The proposed method employs the FEM equilibrium equation and formulates it as a filtering process to estimate soft tissue behavior using real-time measurement data. The model is temporally discretized using the Newmark method and further formulated as the system state equation. Simulation results demonstrate that the computational time of KF-FEM is approximately 10 times shorter than the traditional FEM and it is still as accurate as the traditional FEM. The normalized root-mean-square error of the proposed KF-FEM in reference to the traditional FEM is computed as 0.0116. It is concluded that the proposed method significantly improves the computational performance of the traditional FEM without sacrificing FEM accuracy. The proposed method also filters noises involved in system state and measurement data.

Fetal tissue banking for transplantation: characteristics of the donor population and considerations for donor and tissue screening.

PubMed

Newman-Gage, H; Bravo, D; Holmberg, L; Mason, J; Eisenhower, M; Nekhani, N; Fantel, A

2000-01-01

We initiated this study to evaluate the suitability for therapeutic use in transplantation of tissues obtained from human abortuses. We have developed protocols for the collection, handling and preservation of hepatic stem cells from electively aborted embryos and have developed methods for assessment of the cells so derived and processed. In this paper we present our findings regarding screening of potential donors, acquisition of fetal tissues, and assessment of the tissues for potentially infectious contaminants. We assess the suitability of the tissue donors according to current standards used for donors of commonly transplanted tissues (e.g., bone grafts, skin grafts and heart valves) and present data regarding the real availability of tissues from elective abortion procedures that would meet those standard tissue banking criteria.We specifically evaluated the donor's willingness to provide a blood sample for testing, conducted a detailed interview similar to those used for typical organ and tissue donors, and assessed the type and incidence of contamination in collected tissues. We find that although many women are willing to consent to use of the tissues for transplantation, attrition from the study for various reasons results in few fetal organs ultimately realistically available for transplantation. Typical reasons for attrition include: unwillingness to have a blood sample drawn or tested, positive serology results, social/medical high risk factors for acquisition of transmissible disease, no identifiable organs available, and unacceptable microbial contamination. Thus, although it might seem that due to the numbers of abortions performed annually, that there would be substantial numbers of suitable tissues available, only a small proportion are truly suitable for transplantation.

Degradation behavior of, and tissue response to photo-crosslinked poly(trimethylene carbonate) networks.

PubMed

Rongen, Jan J; van Bochove, Bas; Hannink, Gerjon; Grijpma, Dirk W; Buma, Pieter

2016-11-01

Photo-crosslinked networks prepared from three-armed methacrylate functionalized PTMC oligomers (PTMC-tMA macromers) are attractive materials for developing an anatomically correct meniscus scaffold. In this study, we evaluated cell specific biocompatibility, in vitro and in vivo degradation behavior of, and tissue response to, such PTMC networks. By evaluating PTMC networks prepared from PTMC-tMA macromers of different molecular weights, we were able to assess the effect of macromer molecular weight on the degradation rate of the PTMC network obtained after photo-crosslinking. Three photo-crosslinked networks with different crosslinking densities were prepared using PTMC-tMA macromers with molecular weights 13.3, 17.8, and 26.7 kg/mol. Good cell biocompatibility was demonstrated in a proliferation assay with synovium derived cells. PTMC networks degraded slowly, but statistically significant, both in vitro as well as subcutaneously in rats. Networks prepared from macromers with higher molecular weights demonstrated increased degradation rates compared to networks prepared from initial macromers of lowest molecular weight. The degradation process took place via surface erosion. The PTMC networks showed good tissue tolerance during subcutaneous implantation, to which the tissue response was characterized by the presence of fibrous tissue and encapsulation of the implants. Concluding, we developed cell and tissue biocompatible, photo-crosslinked PTMC networks using PTMC-tMA macromers with relatively high molecular weights. These photo-crosslinked PTMC networks slowly degrade by a surface erosion process. Increasing the crosslinking density of these networks decreases the rate of surface degradation. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2823-2832, 2016. © 2016 Wiley Periodicals, Inc.

The variation trends of SFRP2 methylation of tissue, feces, and blood detection in colorectal cancer development.

PubMed

Sui, Chengguang; Ma, Jianzhong; Chen, Qun; Yang, Yang

2016-07-01

The susceptibility of secreted frizzled-related protein 2 (SFRP2) methylation in colorectal cancer (CRC) has been studied previously. The aim of this study was to determine the risk sizes and variation trends of SFRP2 methylation in CRC development in Chinese populations. Subgroup meta-analysis and the least-squares curve-fitting method were carried out to analyze the risk of SFRP2 methylation in tissue, feces, and blood detection from 2221 samples, including a total of 1103 cases of CRC, 459 cases of adenoma, 257 cases of polyps, and 402 controls. The data showed that odds ratios (95% confidence intervals) between CRC and controls for tissue, feces, and blood detection were 334.01 (104.42-1068.39), 63.76 (20.62-197.63), and 133.75 (18.32-976.32), respectively. There were also significant differences between tissue and feces or blood as well as between feces and blood methylation frequency. These results showed that the risk size in tissue was much greater than that in feces and that in blood. The results pointed out that three curves in tissue, feces, and blood detection described the variation trends of methylation incidence from the control to polyp, to adenoma and to CRC, and that the variation trend of the risk size of SFRP2 methylation was synchronized with the histological evolution process of CRC. The variation trend of the risk size of SFRP2 methylation incidence is consistent with the histological evolution process of CRC. The susceptibility to SFRP2 methylation is an important biomarker in the study of early diagnosis of CRC and high-risk patients.

Regeneration of eye tissues is modulated by altered levels of gravity at 1g, 2g, and in microgravity during spaceflight

NASA Astrophysics Data System (ADS)

Grigoryan, Eleonora; Almeida, Eduardo; Mitashov, Victor

The pursuit of human space exploration requires detailed knowledge of microgravity-related changes in fundamental biological processes, and their effects on health. Normal regeneration of organs and tissues is one such fundamental process that allows maintenance of vitality and function of living organisms. Animal models of tissue regeneration include the newt (Pleurodeles waltl, Urodela) eye, which has been extensively used by our team in Russian Bion and Foton microgravity experiments since 1985, and in recent NASA 2.5 meter diameter centrifuge hypergravity experiments. In total, these experiments allow us to draw several broad conclusions: Newt lens regeneration is significantly altered in microgravity and hypergravity relative to 1g controls. Lenses formed in microgravity are larger and more developed than those regenerated in 1g controls; Microgravity alterations of lens regeneration can persist after spaceflight, and continue to affect repeated removal and regeneration of the lens after return to 1g; Microgravity increases the numbers of early stage regenerative proliferating BrdU-labeled cells in dorsal iris progenitors and in the lens regenerate. Regeneration under hypergravity conditions at 2g inhibits lens regeneration, and often causes retinal detachment. Molecular mechanisms regulating lens regeneration rate include FGF2 signaling, (a key pathway for eye tissue development and regeneration), and an expression of stress-related proteins - HSPs. In conclusion, regeneration of lens and other eye tissues in the newt is sensitive to, and regulated by the level of gravity mechanotransduction and developmental signaling pathways, with microgravity favoring stem cell progenitor proliferation, and gravity at 1g promoting terminal differentiation, while hypergravity at 2g often causes damage of delicate regenerating tissues.

The Establishment of the First Cancer Tissue Biobank at a Hispanic-Serving Institution: A National Cancer Institute–Funded Initiative between Moffitt Cancer Center in Florida and the Ponce School of Medicine and Health Sciences in Puerto Rico

PubMed Central

Flores, Idhaliz; Muñoz-Antonia, Teresita; Matta, Jaime; García, Miosotis; Fenstermacher, David; Gutierrez, Sylvia; Seijo, Edward; Torres-Ruiz, Jose’; Pledger, W. Jack

2011-01-01

Population-based studies are important to address emerging issues in health disparities among populations. The Partnership between the Moffitt Cancer Center (MCC) in Florida and the Ponce School of Medicine and Health Sciences (PSMHS) in Puerto Rico (the PSMHS-MCC Partnership) was developed to facilitate high-quality research, training, and community outreach focusing on the Puerto Rican population in the island and in the mainland, with funding from the National Cancer Institute. We report here the establishment of a Tissue Biobank at PSMHS, modeled after the MCC tissue biorepository, to support translational research projects on this minority population. This facility, the Puerto Rico Tissue Biobank, was jointly developed by a team of basic and clinical scientists from both institutions in close collaboration with the administrators and clinical faculty of the tissue accrual sites. The efforts required and challenges that needed to be overcome to establish the first functional, centralized cancer-related biobank in Puerto Rico, and to ensure that it continuously evolves to address new needs of this underserved Hispanic population, are described. As a result of the collaborative efforts between PSMHS and MCC, a tissue procurement algorithm was successfully established to acquire, process, store, and conduct pathological analyses of cancer-related biospecimens and their associated clinical-pathological data from Puerto Rican patients with cancer recruited at a tertiary hospital setting. All protocols in place are in accordance with standard operational procedures that ensure high quality of biological materials and patient confidentiality. The processes described here provide a model that can be applied to achieve the establishment of a functional biobank in similar settings. PMID:24836632

Growth factors in urologic tissues: detection, characterization, and clinical applications.

PubMed

Mydlo, J H; Macchia, R J

1992-12-01

During the last two decades, enormous strides have been made in understanding cellular and molecular biology. The direction of treatment of many neoplasms and other diseases are starting at the microscopic level. Growth factors are polypeptides that play a part in the development and maintenance of living tissues. We, as well as others, have investigated the role that growth factors play particularly in urologic tissues, both benign and malignant. We review several well-known growth factors and their function in prostate, kidney, and bladder tissues, as well as their functions in other regulating processes of the human body, and also the use of growth factors as tumor markers, and antibodies to growth factors as possible treatment of disease.

Synthetic biodegradable functional polymers for tissue engineering: a brief review.

PubMed

BaoLin, Guo; Ma, Peter X

2014-04-01

Scaffolds play a crucial role in tissue engineering. Biodegradable polymers with great processing flexibility are the predominant scaffolding materials. Synthetic biodegradable polymers with well-defined structure and without immunological concerns associated with naturally derived polymers are widely used in tissue engineering. The synthetic biodegradable polymers that are widely used in tissue engineering, including polyesters, polyanhydrides, polyphosphazenes, polyurethane, and poly (glycerol sebacate) are summarized in this article. New developments in conducting polymers, photoresponsive polymers, amino-acid-based polymers, enzymatically degradable polymers, and peptide-activated polymers are also discussed. In addition to chemical functionalization, the scaffold designs that mimic the nano and micro features of the extracellular matrix (ECM) are presented as well, and composite and nanocomposite scaffolds are also reviewed.

Changes in expression of the lysosomal membrane glycoprotein, LAMP-1 in interdigital regions during embryonic mouse limb development, in vivo and in vitro.

PubMed

Stewart, S; Yi, S; Kassabian, G; Mayo, M; Sank, A; Shuler, C

2000-06-01

Syndactyly, a failure of the digits to separate into individual units, affects about 8 to 9 per 1000 newborns and results from an aberration of the normal development of the interdigital tissues. Limb digit separation is the result of programmed cell death (apoptosis). Lysosomes play a role in the process of cell self-destruction. Our experiment was designed to test the hypothesis that the intensity of interdigital lysosomes increases during the separation of digits in vivo and in vitro. The primary mouse monoclonal antibody, 1D4B, detects the presence of lysosomes by identifying the LAMP-1 glycoprotein on the lysosome cell membrane. In our experiment this antibody immunodetected interdigital lysosome proteins in serial sections of limbs from Swiss-Webster mouse embryos, gestational ages E12.5 through E15, key developmental stages for digit separation. Digit separation was associated with an increase in intensity of lysosomal protein staining. In E12.5 limbs, the presence of lysosomes was enriched in the distal aspect of the interdigital tissue. However, the number of lysosomes markedly increased in the E13 and E14 limbs, including the entire length and width of the interdigital tissue in the E14 limbs. This lysosomal protein presence in E14 limbs was significant compared to E12.5, E13, and E15 limbs. By day 12.5, the mouse embryo limb is committed to digit separation. Addition of retinoic acid to the culture medium of limbs earlier in development, such as E12, results in induction of the process of digit separation. Cultured E12 limbs that did not receive an addition of retinoic acid, did not show digit separation. We conclude that in the limb development process, the enrichment in interdigit LAMP-1 proteins, may indicate a relationship between lysosomes, apoptosis, and digit separation. We also conclude that retinoic acid has an important role in digit separation in vivo, as shown in limb development, and demonstrated through the addition of retinoic acid to media of cultured tissues.

Hyperspectral imaging solutions for brain tissue metabolic and hemodynamic monitoring: past, current and future developments

NASA Astrophysics Data System (ADS)

Giannoni, Luca; Lange, Frédéric; Tachtsidis, Ilias

2018-04-01

Hyperspectral imaging (HSI) technologies have been used extensively in medical research, targeting various biological phenomena and multiple tissue types. Their high spectral resolution over a wide range of wavelengths enables acquisition of spatial information corresponding to different light-interacting biological compounds. This review focuses on the application of HSI to monitor brain tissue metabolism and hemodynamics in life sciences. Different approaches involving HSI have been investigated to assess and quantify cerebral activity, mainly focusing on: (1) mapping tissue oxygen delivery through measurement of changes in oxygenated (HbO2) and deoxygenated (HHb) hemoglobin; and (2) the assessment of the cerebral metabolic rate of oxygen (CMRO2) to estimate oxygen consumption by brain tissue. Finally, we introduce future perspectives of HSI of brain metabolism, including its potential use for imaging optical signals from molecules directly involved in cellular energy production. HSI solutions can provide remarkable insight in understanding cerebral tissue metabolism and oxygenation, aiding investigation on brain tissue physiological processes.

A dynamic cellular vertex model of growing epithelial tissues

NASA Astrophysics Data System (ADS)

Lin, Shao-Zhen; Li, Bo; Feng, Xi-Qiao

2017-04-01

Intercellular interactions play a significant role in a wide range of biological functions and processes at both the cellular and tissue scales, for example, embryogenesis, organogenesis, and cancer invasion. In this paper, a dynamic cellular vertex model is presented to study the morphomechanics of a growing epithelial monolayer. The regulating role of stresses in soft tissue growth is revealed. It is found that the cells originating from the same parent cell in the monolayer can orchestrate into clustering patterns as the tissue grows. Collective cell migration exhibits a feature of spatial correlation across multiple cells. Dynamic intercellular interactions can engender a variety of distinct tissue behaviors in a social context. Uniform cell proliferation may render high and heterogeneous residual compressive stresses, while stress-regulated proliferation can effectively release the stresses, reducing the stress heterogeneity in the tissue. The results highlight the critical role of mechanical factors in the growth and morphogenesis of epithelial tissues and help understand the development and invasion of epithelial tumors.

3D Bioprinting for Tissue and Organ Fabrication

PubMed Central

Zhang, Yu Shrike; Yang, Jingzhou; Jia, Weitao; Dell’Erba, Valeria; Assawes, Pribpandao; Shin, Su Ryon; Dokmeci, Mehmet Remzi; Oklu, Rahmi; Khademhosseini, Ali

2016-01-01

The field of regenerative medicine has progressed tremendously over the past few decades in its ability to fabricate functional tissue substitutes. Conventional approaches based on scaffolding and microengineering are limited in their capacity of producing tissue constructs with precise biomimetic properties. Three-dimensional (3D) bioprinting technology, on the other hand, promises to bridge the divergence between artificially engineered tissue constructs and native tissues. In a sense, 3D bioprinting offers unprecedented versatility to co-deliver cells and biomaterials with precise control over their compositions, spatial distributions, and architectural accuracy, therefore achieving detailed or even personalized recapitulation of the fine shape, structure, and architecture of target tissues and organs. Here we briefly describe recent progresses of 3D bioprinting technology and associated bioinks suitable for the printing process. We then focus on the applications of this technology in fabrication of biomimetic constructs of several representative tissues and organs, including blood vessel, heart, liver, and cartilage. We finally conclude with future challenges in 3D bioprinting as well as potential solutions for further development. PMID:27126775

3D Bioprinting for Tissue and Organ Fabrication.

PubMed

Zhang, Yu Shrike; Yue, Kan; Aleman, Julio; Moghaddam, Kamyar Mollazadeh; Bakht, Syeda Mahwish; Yang, Jingzhou; Jia, Weitao; Dell'Erba, Valeria; Assawes, Pribpandao; Shin, Su Ryon; Dokmeci, Mehmet Remzi; Oklu, Rahmi; Khademhosseini, Ali

2017-01-01

The field of regenerative medicine has progressed tremendously over the past few decades in its ability to fabricate functional tissue substitutes. Conventional approaches based on scaffolding and microengineering are limited in their capacity of producing tissue constructs with precise biomimetic properties. Three-dimensional (3D) bioprinting technology, on the other hand, promises to bridge the divergence between artificially engineered tissue constructs and native tissues. In a sense, 3D bioprinting offers unprecedented versatility to co-deliver cells and biomaterials with precise control over their compositions, spatial distributions, and architectural accuracy, therefore achieving detailed or even personalized recapitulation of the fine shape, structure, and architecture of target tissues and organs. Here we briefly describe recent progresses of 3D bioprinting technology and associated bioinks suitable for the printing process. We then focus on the applications of this technology in fabrication of biomimetic constructs of several representative tissues and organs, including blood vessel, heart, liver, and cartilage. We finally conclude with future challenges in 3D bioprinting as well as potential solutions for further development.

Mueller coherency matrix method for contrast image in tissue polarimetry

NASA Astrophysics Data System (ADS)

Arce-Diego, J. L.; Fanjul-Vélez, F.; Samperio-García, D.; Pereda-Cubián, D.

2007-07-01

In this work, we propose the use of the Mueller Coherency matrix of biological tissues in order to increase the information from tissue images and so their contrast. This method involves different Mueller Coherency matrix based parameters, like the eigenvalues analysis, the entropy factor calculation, polarization components crosstalks, linear and circular polarization degrees, hermiticity or the Quaternions analysis in case depolarisation properties of tissue are sufficiently low. All these parameters make information appear clearer and so increase image contrast, so pathologies like cancer could be detected in a sooner stage of development. The election will depend on the concrete pathological process under study. This Mueller Coherency matrix method can be applied to a single tissue point, or it can be combined with a tomographic technique, so as to obtain a 3D representation of polarization contrast parameters in pathological tissues. The application of this analysis to concrete diseases can lead to tissue burn depth estimation or cancer early detection.

OCT-based approach to local relaxations discrimination from translational relaxation motions

NASA Astrophysics Data System (ADS)

Matveev, Lev A.; Matveyev, Alexandr L.; Gubarkova, Ekaterina V.; Gelikonov, Grigory V.; Sirotkina, Marina A.; Kiseleva, Elena B.; Gelikonov, Valentin M.; Gladkova, Natalia D.; Vitkin, Alex; Zaitsev, Vladimir Y.

2016-04-01

Multimodal optical coherence tomography (OCT) is an emerging tool for tissue state characterization. Optical coherence elastography (OCE) is an approach to mapping mechanical properties of tissue based on OCT. One of challenging problems in OCE is elimination of the influence of residual local tissue relaxation that complicates obtaining information on elastic properties of the tissue. Alternatively, parameters of local relaxation itself can be used as an additional informative characteristic for distinguishing the tissue in normal and pathological states over the OCT image area. Here we briefly present an OCT-based approach to evaluation of local relaxation processes in the tissue bulk after sudden unloading of its initial pre-compression. For extracting the local relaxation rate we evaluate temporal dependence of local strains that are mapped using our recently developed hybrid phase resolved/displacement-tracking (HPRDT) approach. This approach allows one to subtract the contribution of global displacements of scatterers in OCT scans and separate the temporal evolution of local strains. Using a sample excised from of a coronary arteria, we demonstrate that the observed relaxation of local strains can be reasonably fitted by an exponential law, which opens the possibility to characterize the tissue by a single relaxation time. The estimated local relaxation times are assumed to be related to local biologically-relevant processes inside the tissue, such as diffusion, leaking/draining of the fluids, local folding/unfolding of the fibers, etc. In general, studies of evolution of such features can provide new metrics for biologically-relevant changes in tissue, e.g., in the problems of treatment monitoring.

The developing human connectome project: A minimal processing pipeline for neonatal cortical surface reconstruction.

PubMed

Makropoulos, Antonios; Robinson, Emma C; Schuh, Andreas; Wright, Robert; Fitzgibbon, Sean; Bozek, Jelena; Counsell, Serena J; Steinweg, Johannes; Vecchiato, Katy; Passerat-Palmbach, Jonathan; Lenz, Gregor; Mortari, Filippo; Tenev, Tencho; Duff, Eugene P; Bastiani, Matteo; Cordero-Grande, Lucilio; Hughes, Emer; Tusor, Nora; Tournier, Jacques-Donald; Hutter, Jana; Price, Anthony N; Teixeira, Rui Pedro A G; Murgasova, Maria; Victor, Suresh; Kelly, Christopher; Rutherford, Mary A; Smith, Stephen M; Edwards, A David; Hajnal, Joseph V; Jenkinson, Mark; Rueckert, Daniel

2018-06-01

The Developing Human Connectome Project (dHCP) seeks to create the first 4-dimensional connectome of early life. Understanding this connectome in detail may provide insights into normal as well as abnormal patterns of brain development. Following established best practices adopted by the WU-MINN Human Connectome Project (HCP), and pioneered by FreeSurfer, the project utilises cortical surface-based processing pipelines. In this paper, we propose a fully automated processing pipeline for the structural Magnetic Resonance Imaging (MRI) of the developing neonatal brain. This proposed pipeline consists of a refined framework for cortical and sub-cortical volume segmentation, cortical surface extraction, and cortical surface inflation, which has been specifically designed to address considerable differences between adult and neonatal brains, as imaged using MRI. Using the proposed pipeline our results demonstrate that images collected from 465 subjects ranging from 28 to 45 weeks post-menstrual age (PMA) can be processed fully automatically; generating cortical surface models that are topologically correct, and correspond well with manual evaluations of tissue boundaries in 85% of cases. Results improve on state-of-the-art neonatal tissue segmentation models and significant errors were found in only 2% of cases, where these corresponded to subjects with high motion. Downstream, these surfaces will enhance comparisons of functional and diffusion MRI datasets, supporting the modelling of emerging patterns of brain connectivity. Copyright © 2018 Elsevier Inc. All rights reserved.

Micro-processing of polymers and biological materials using high repetition rate femtosecond laser pulses

NASA Astrophysics Data System (ADS)

Ding, Li

High repetition rate femtosecond laser micro-processing has been applied to ophthalmological hydrogel polymers and ocular tissues to create novel refractive and diffractive structures. Through the optimization of laser irradiation conditions and material properties, this technology has become feasible for future industrial applications and clinical practices. A femtosecond laser micro-processing workstation has been designed and developed. Different experimental parameters of the workstation such as laser pulse duration, focusing lens, and translational stages have been described and discussed. Diffractive gratings and three-dimensional waveguides have been fabricated and characterized in hydrogel polymers, and refractive index modifications as large as + 0.06 have been observed within the laser-irradiated region. Raman spectroscopic studies have shown that our femtosecond laser micro-processing induces significant thermal accumulation, resulting in a densification of the polymer network and increasing the localized refractive index of polymers within the laser irradiated region. Different kinds of dye chromophores have been doped in hydrogel polymers to enhance the two-photon absorption during femtosecond laser micro-processing. As the result, laser scanning speed can be greatly increased while the large refractive index modifications remain. Femtosecond laser wavelength and pulse energy as well as water and dye concentration of the hydrogels are optimized. Lightly fixed ocular tissues such as corneas and lenses have been micro-processed by focused femtosecond laser pulses, and refractive index modifications without any tissue-breakdown are observed within the stromal layer of the corneas and the cortex of the lenses. Living corneas are doped with Sodium Fluorescein to increase the two-photon absorption during the laser micro-processing, and laser scanning speed can be greatly increased while inducing large refractive index modifications. No evidence of cell death has been observed in or around the laser-induced refractive index modification regions. These results support the notion that femtosecond laser micro-processing method may be an excellent means of altering the refraction or higher order aberration content of corneal tissue without cell death and short-term tissue damage, and has been named as Intra-tissue Refractive Index Shaping (IRIS). The femtosecond laser micro-processing workstation has also been employed for laser transfection of single defined cells. Some preliminary results suggest that this method can be used to trace individual cells and record their biological and morphological evolution, which is quite promising in many biomedical applications especially in immunology science. In conclusion, high repetition rate femtosecond laser micro-processing has been employed to fabricate microstructures in ophthalmological hydrogels and ocular tissues. Its unique three-dimensional capability over transparent materials and biological media makes it a powerful tool and will greatly impact the future of laser material-processing.

Computation and application of tissue-specific gene set weights.

PubMed

Frost, H Robert

2018-04-06

Gene set testing, or pathway analysis, has become a critical tool for the analysis of highdimensional genomic data. Although the function and activity of many genes and higher-level processes is tissue-specific, gene set testing is typically performed in a tissue agnostic fashion, which impacts statistical power and the interpretation and replication of results. To address this challenge, we have developed a bioinformatics approach to compute tissuespecific weights for individual gene sets using information on tissue-specific gene activity from the Human Protein Atlas (HPA). We used this approach to create a public repository of tissue-specific gene set weights for 37 different human tissue types from the HPA and all collections in the Molecular Signatures Database (MSigDB). To demonstrate the validity and utility of these weights, we explored three different applications: the functional characterization of human tissues, multi-tissue analysis for systemic diseases and tissue-specific gene set testing. All data used in the reported analyses is publicly available. An R implementation of the method and tissue-specific weights for MSigDB gene set collections can be downloaded at http://www.dartmouth.edu/∼hrfrost/TissueSpecificGeneSets. rob.frost@dartmouth.edu.

Angiogenesis in tissue engineering: from concept to the vascularization of scaffold construct

NASA Astrophysics Data System (ADS)

Amirah Ishak, Siti; Pangestu Djuansjah, J. R.; Kadir, M. R. Abdul; Sukmana, Irza

2014-06-01

Angiogenesis, the formation of micro-vascular network from the preexisting vascular vessels, has been studied in the connection to the normal developmental process as well as numerous diseases. In tissue engineering research, angiogenesis is also essential to promote micro-vascular network inside engineered tissue constructs, mimicking a functional blood vessel in vivo. Micro-vascular network can be used to maintain adequate tissue oxygenation, nutrient transfer and waste removal. One of the problems faced by angiogenesis researchers is to find suitable in vitro assays and methods for assessing the effect of regulators on angiogenesis and micro-vessel formation. The assay would be reliable and repeatable with easily quantifiable with physiologically relevant. This review aims to highlights recent advanced and future challenges in developing and using an in vitro angiogenesis assay for the application on biomedical and tissue engineering research.

Optical Spectroscopy and Imaging for the Noninvasive Evaluation of Engineered Tissues

PubMed Central

Rice, William L.; Hronik-Tupaj, Marie; Kaplan, David L.

2008-01-01

Optical spectroscopy and imaging approaches offer the potential to noninvasively assess different aspects of the cellular, extracellular matrix, and scaffold components of engineered tissues. In addition, the combination of multiple imaging modalities within a single instrument is highly feasible, allowing acquisition of complementary information related to the structure, organization, biochemistry, and physiology of the sample. The ability to characterize and monitor the dynamic interactions that take place as engineered tissues develop promises to enhance our understanding of the interdependence of processes that ultimately leads to functional tissue outcomes. It is expected that this information will impact significantly upon our abilities to optimize the design of biomaterial scaffolds, bioreactors, and cell systems. Here, we review the principles and performance characteristics of the main methodologies that have been exploited thus far, and we present examples of corresponding tissue engineering studies. PMID:18844604

Strip mosaicing confocal microscopy for rapid imaging over large areas of excised tissue

NASA Astrophysics Data System (ADS)

Abeytunge, Sanjee; Li, Yongbiao; Larson, Bjorg; Peterson, Gary; Toledo-Crow, Ricardo; Rajadhyaksha, Milind

2012-03-01

Confocal mosaicing microscopy is a developing technology platform for imaging tumor margins directly in fresh tissue, without the processing that is required for conventional pathology. Previously, basal cell carcinoma margins were detected by mosaicing of confocal images of 12 x 12 mm2 of excised tissue from Mohs surgery. This mosaicing took 9 minutes. Recently we reported the initial feasibility of a faster approach called "strip mosaicing" on 10 x 10 mm2 of tissue that was demonstrated in 3 minutes. In this paper we report further advances in instrumentation and software. Rapid mosaicing of confocal images on large areas of fresh tissue potentially offers a means to perform pathology at the bedside. Thus, strip mosaicing confocal microscopy may serve as an adjunct to pathology for imaging tumor margins to guide surgery.

[Tissue printing; the potential application of 3D printing in medicine].

PubMed

Visser, Jetze; Melchels, Ferry P W; Dhert, Wouter J A; Malda, Jos

2013-01-01

Complex structures based on a digital blueprint can be created using a 3D printer. As this blueprint can be created using patient imaging data, there are many potential patient-specific applications of 3D printing in medicine. Individually printed metal implants and synthetic devices are currently being used on a limited scale in clinical practice. Researchers in the field of regenerative medicine are now going a step further by printing a combination of cells, growth factors and biomaterials. This process is known as 'bioprinting'. It can be used to copy the complex organization of natural tissue required to repair or replace damaged tissues or organs. The technique needs to be optimized, however, and more knowledge is required regarding the development of printed living constructs into functional tissues before 'tissue from the printer' can be clinically applied.

Patient-derived Models of Human Breast Cancer: Protocols for In vitro and In vivo Applications in Tumor Biology and Translational Medicine

PubMed Central

DeRose, Yoko S.; Gligorich, Keith M.; Wang, Guoying; Georgelas, Ann; Bowman, Paulette; Courdy, Samir J.; Welm, Alana L.; Welm, Bryan E.

2013-01-01

Research models that replicate the diverse genetic and molecular landscape of breast cancer are critical for developing the next generation therapeutic entities that can target specific cancer subtypes. Patient-derived tumorgrafts, generated by transplanting primary human tumor samples into immune-compromised mice, are a valuable method to model the clinical diversity of breast cancer in mice, and are a potential resource in personalized medicine. Primary tumorgrafts also enable in vivo testing of therapeutics and make possible the use of patient cancer tissue for in vitro screens. Described in this unit are a variety of protocols including tissue collection, biospecimen tracking, tissue processing, transplantation, and 3-dimensional culturing of xenografted tissue, that enable use of bona fide uncultured human tissue in designing and validating cancer therapies. PMID:23456611

Importance of dual delivery systems for bone tissue engineering.

PubMed

Farokhi, Mehdi; Mottaghitalab, Fatemeh; Shokrgozar, Mohammad Ali; Ou, Keng-Liang; Mao, Chuanbin; Hosseinkhani, Hossein

2016-03-10

Bone formation is a complex process that requires concerted function of multiple growth factors. For this, it is essential to design a delivery system with the ability to load multiple growth factors in order to mimic the natural microenvironment for bone tissue formation. However, the short half-lives of growth factors, their relatively large size, slow tissue penetration, and high toxicity suggest that conventional routes of administration are unlikely to be effective. Therefore, it seems that using multiple bioactive factors in different delivery systems can develop new strategies for improving bone tissue regeneration. Combination of these factors along with biomaterials that permit tunable release profiles would help to achieve truly spatiotemporal regulation during delivery. This review summarizes the various dual-control release systems that are used for bone tissue engineering. Copyright © 2015 Elsevier B.V. All rights reserved.

Characterization of a novel anthropomorphic plastinated lung phantom

PubMed Central

Yoon, Sungwon; Henry, Robert W.; Bouley, Donna M.; Bennett, N. Robert; Fahrig, Rebecca

2008-01-01

Phantoms are widely used during the development of new imaging systems and algorithms. For development and optimization of new imaging systems such as tomosynthesis, where conventional image quality metrics may not be applicable, a realistic phantom that can be used across imaging systems is desirable. A novel anthropomorphic lung phantom was developed by plastination of an actual pig lung. The plastinated phantom is characterized and compared with reference to in vivo images of the same tissue prior to plastination using high resolution 3D CT. The phantom is stable over time and preserves the anatomical features and relative locations of the in vivo sample. The volumes for different tissue types in the phantom are comparable to the in vivo counterparts, and CT numbers for different tissue types fall within a clinically useful range. Based on the measured CT numbers, the phantom cardiac tissue experienced a 92% decrease in bulk density and the phantom pulmonary tissue experienced a 78% decrease in bulk density compared to their in vivo counterparts. By-products in the phantom from the room temperature vulcanizing silicone and plastination process are also identified. A second generation phantom, which eliminates most of the by-products, is presented. Such anthropomorphic phantoms can be used to evaluate a wide range of novel imaging systems. PMID:19175148

Matrix factorization reveals aging-specific co-expression gene modules in the fat and muscle tissues in nonhuman primates

NASA Astrophysics Data System (ADS)

Wang, Yongcui; Zhao, Weiling; Zhou, Xiaobo

2016-10-01

Accurate identification of coherent transcriptional modules (subnetworks) in adipose and muscle tissues is important for revealing the related mechanisms and co-regulated pathways involved in the development of aging-related diseases. Here, we proposed a systematically computational approach, called ICEGM, to Identify the Co-Expression Gene Modules through a novel mathematical framework of Higher-Order Generalized Singular Value Decomposition (HO-GSVD). ICEGM was applied on the adipose, and heart and skeletal muscle tissues in old and young female African green vervet monkeys. The genes associated with the development of inflammation, cardiovascular and skeletal disorder diseases, and cancer were revealed by the ICEGM. Meanwhile, genes in the ICEGM modules were also enriched in the adipocytes, smooth muscle cells, cardiac myocytes, and immune cells. Comprehensive disease annotation and canonical pathway analysis indicated that immune cells, adipocytes, cardiomyocytes, and smooth muscle cells played a synergistic role in cardiac and physical functions in the aged monkeys by regulation of the biological processes associated with metabolism, inflammation, and atherosclerosis. In conclusion, the ICEGM provides an efficiently systematic framework for decoding the co-expression gene modules in multiple tissues. Analysis of genes in the ICEGM module yielded important insights on the cooperative role of multiple tissues in the development of diseases.

Gap geometry dictates epithelial closure efficiency

PubMed Central

Ravasio, Andrea; Cheddadi, Ibrahim; Chen, Tianchi; Pereira, Telmo; Ong, Hui Ting; Bertocchi, Cristina; Brugues, Agusti; Jacinto, Antonio; Kabla, Alexandre J.; Toyama, Yusuke; Trepat, Xavier; Gov, Nir; Neves de Almeida, Luís; Ladoux, Benoit

2015-01-01

Closure of wounds and gaps in tissues is fundamental for the correct development and physiology of multicellular organisms and, when misregulated, may lead to inflammation and tumorigenesis. To re-establish tissue integrity, epithelial cells exhibit coordinated motion into the void by active crawling on the substrate and by constricting a supracellular actomyosin cable. Coexistence of these two mechanisms strongly depends on the environment. However, the nature of their coupling remains elusive because of the complexity of the overall process. Here we demonstrate that epithelial gap geometry in both in vitro and in vivo regulates these collective mechanisms. In addition, the mechanical coupling between actomyosin cable contraction and cell crawling acts as a large-scale regulator to control the dynamics of gap closure. Finally, our computational modelling clarifies the respective roles of the two mechanisms during this process, providing a robust and universal mechanism to explain how epithelial tissues restore their integrity. PMID:26158873

A Reconstruction Method for the Estimation of Temperatures of Multiple Sources Applied for Nanoparticle-Mediated Hyperthermia.

PubMed

Steinberg, Idan; Tamir, Gil; Gannot, Israel

2018-03-16

Solid malignant tumors are one of the leading causes of death worldwide. Many times complete removal is not possible and alternative methods such as focused hyperthermia are used. Precise control of the hyperthermia process is imperative for the successful application of such treatment. To that end, this research presents a fast method that enables the estimation of deep tissue heat distribution by capturing and processing the transient temperature at the boundary based on a bio-heat transfer model. The theoretical model is rigorously developed and thoroughly validated by a series of experiments. A 10-fold improvement is demonstrated in resolution and visibility on tissue mimicking phantoms. The inverse problem is demonstrated as well with a successful application of the model for imaging deep-tissue embedded heat sources. Thereby, allowing the physician then ability to dynamically evaluate the hyperthermia treatment efficiency in real time.

Fracture healing: mechanisms and interventions

PubMed Central

Einhorn, Thomas A.; Gerstenfeld, Louis C.

2015-01-01

Fractures are the most common large-organ, traumatic injuries to humans. The repair of bone fractures is a postnatal regenerative process that recapitulates many of the ontological events of embryonic skeletal development. Although fracture repair usually restores the damaged skeletal organ to its pre-injury cellular composition, structure and biomechanical function, about 10% of fractures will not heal normally. This article reviews the developmental progression of fracture healing at the tissue, cellular and molecular levels. Innate and adaptive immune processes are discussed as a component of the injury response, as are environmental factors, such as the extent of injury to the bone and surrounding tissue, fixation and the contribution of vascular tissues. We also present strategies for fracture treatment that have been tested in animal models and in clinical trials or case series. The biophysical and biological basis of the molecular actions of various therapeutic approaches, including recombinant human bone morphogenetic proteins and parathyroid hormone therapy, are also discussed. PMID:25266456

Tomographic image reconstruction using x-ray phase information

NASA Astrophysics Data System (ADS)

Momose, Atsushi; Takeda, Tohoru; Itai, Yuji; Hirano, Keiichi

1996-04-01

We have been developing phase-contrast x-ray computed tomography (CT) to make possible the observation of biological soft tissues without contrast enhancement. Phase-contrast x-ray CT requires for its input data the x-ray phase-shift distributions or phase-mapping images caused by an object. These were measured with newly developed fringe-scanning x-ray interferometry. Phase-mapping images at different projection directions were obtained by rotating the object in an x-ray interferometer, and were processed with a standard CT algorithm. A phase-contrast x-ray CT image of a nonstained cancerous tissue was obtained using 17.7 keV synchrotron x rays with 12 micrometer voxel size, although the size of the observation area was at most 5 mm. The cancerous lesions were readily distinguishable from normal tissues. Moreover, fine structures corresponding to cancerous degeneration and fibrous tissues were clearly depicted. It is estimated that the present system is sensitive down to a density deviation of 4 mg/cm3.

Establishing a composite tissue allotransplantation program.

PubMed

Pomahac, Bohdan

2012-01-01

Composite tissue allotransplantation (CTA) has emerged as a promising surgical option to restore the form and function of missing or severely damaged structures such as the face, hands, or trachea. Currently, there are four active CTA programs in the United States and numerous others under development. The process of development of a CTA program in the United States involves successful collaboration between a strong project leader with vested clinical research interest, a multidisciplinary team of investigators, an Institutional Review Board, a regional Organ Processing Organization (PO), and the hospital's administration. The process of establishment of a CTA program can be slow and lengthy, therefore the project leader must strive to maintain the enthusiasm alive and drive the project forward. At all phases of development, the project must remain focused on the patients, must recognize and address all potential patient safety issues, must take into account the concerns, issues and logistic hurdles faced by the OPO, and must be financially responsible by ensuring that postoperative costs related to medical care and life-long immunosuppression are covered by medical insurance. This article describes the process of establishment of a CTA program at Brigham and Women's Hospital, Boston, MA with special emphasis on strategy and planning. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Quantitatively characterizing microstructural variations of skin tissues during ultraviolet radiation damaging process based on Mueller matrix polarimetry

NASA Astrophysics Data System (ADS)

Sheng, Wei; He, Honghui; Dong, Yang; Ma, Hui

2018-02-01

As one of the most fundamental features of light, polarization can be used to develop imaging techniques which can provide insight into the optical and structural properties of tissues. Especially, the Mueller matrix polarimetry is suitable to detect the changes in collagen and elastic fibres, which are the main compositions of skin tissue. Here we demonstrate a novel quantitative, non-contact and in situ technique to monitor the microstructural variations of skin tissue during ultraviolet radiation (UVR) induced photoaging based on Mueller matrix polarimetry. Specifically, we measure the twodimensional (2D) backscattering Mueller matrices of nude mouse skin samples, then calculate and analyze the Mueller matrix derived parameters during the skin photoaging and self-repairing processes. To induce three-day skin photoaging, the back skin of each mouse is irradiated with UVR (0.05J/cm2) for five minutes per day. After UVR, the microstructures of the nude mouse skin are damaged. During the process of UV damage, we measure the backscattering Mueller matrices of the mouse skin samples and examine the relationship between the Mueller matrix parameters and the microstructural variations of skin tissue quantitatively. The comparisons between the UVR damaged groups with and without sunscreens show that the Mueller matrix derived parameters are potential indicators for fibrous microstructure variation in skin tissue. The pathological examinations and Monte Carlo simulations confirm the relationship between the values of Mueller matrix parameters and the changes of fibrous structures. Combined with smart phones or wearable devices, this technique may have a good application prospect in the fields of cosmetics and dermatological health.

Biocompatibility evaluation of alendronate paste in rat's subcutaneous tissue.

PubMed

Mori, Graziela Garrido; de Moraes, Ivaldo Gomes; Nunes, Daniele Clapes; Castilho, Lithiene Ribeiro; Poi, Wilson Roberto; Capaldi, Maria Luciana P Manzoli

2009-04-01

Alendronate is a known inhibitor of root resorption and the development of alendronate paste would enhance its utilization as intracanal medication. Therefore, this study aimed to investigate the biocompatibility of experimental alendronate paste in subcutaneous tissue of rats, for utilization in teeth susceptible to root resorption. The study was conducted on 15 male rats, weighing approximately 180-200 grams. The rats' dorsal regions were submitted to one incision on the median region and, laterally to the incision, the subcutaneous tissue was raised and gently dissected for introduction of two tubes, in each rat. The tubes were sealed at one end with gutta-percha and taken as control. The tubes were filled with experimental alendronate paste. The animals were killed at 7, 15 and 45 days after surgery and the specimens were processed in laboratory. The histological sections were stained with hematoxylin-eosin and analyzed by light microscopy. Scores were assigned to the inflammatory process and statistically compared by the Tukey test (P < 0.05). Alendronate paste promoted severe inflammation process at 7 days, with statistically significant difference compared to the control (P < 0.05%). However, at 15 days, there was a regression of inflammation and the presence of connective tissue with collagen fibers, fibroblasts and blood vessels was observed. After 45 days, it was observed the presence of well-organized connective tissue, with collagen fibers and fibroblasts, and few inflammatory cells. No statistical difference was observed between the control and experimental paste at 15 and 45 days. The experimental alendronate paste was considered biocompatible with subcutaneous tissue of rat.

Microwave processing of gustatory tissues for immunohistochemistry

PubMed Central

Bond, Amanda; Kinnamon, John C.

2013-01-01

We use immunohistochemistry to study taste cell structure and function as a means to elucidate how taste receptor cells communicate with nerve fibers and adjacent taste cells. This conventional method, however, is time consuming. In the present study we used taste buds from rat circumvallate papillae to compare conventional immunohistochemical tissue processing with microwave processing for the colocalization of several biochemical pathway markers (PLCβ2, syntaxin-1, IP3R3, α-gustducin) and the nuclear stain, Sytox. The results of our study indicate that in microwave versus conventional immunocytochemistry: (1) fixation quality is improved; (2) the amount of time necessary for processing tissue is decreased; (3) antigen retrieval is no longer needed; (4) image quality is superior. In sum, microwave tissue processing of gustatory tissues is faster and superior to conventional immunohistochemical tissue processing for many applications. PMID:23473796

Studying the Brain in a Dish: 3D Cell Culture Models of Human Brain Development and Disease.

PubMed

Brown, Juliana; Quadrato, Giorgia; Arlotta, Paola

2018-01-01

The study of the cellular and molecular processes of the developing human brain has been hindered by access to suitable models of living human brain tissue. Recently developed 3D cell culture models offer the promise of studying fundamental brain processes in the context of human genetic background and species-specific developmental mechanisms. Here, we review the current state of 3D human brain organoid models and consider their potential to enable investigation of complex aspects of human brain development and the underpinning of human neurological disease. © 2018 Elsevier Inc. All rights reserved.

Metabolic inflammation in inflammatory bowel disease: crosstalk between adipose tissue and bowel.

PubMed

Gonçalves, Pedro; Magro, Fernando; Martel, Fátima

2015-02-01

Epidemiological studies show that both the incidence of inflammatory bowel disease (IBD) and the proportion of people with obesity and/or obesity-associated metabolic syndrome increased markedly in developed countries during the past half century. Obesity is also associated with the development of more active IBD and requirement for hospitalization and with a decrease in the time span between diagnosis and surgery. Patients with IBD, especially Crohn's disease, present fat-wrapping or "creeping fat," which corresponds to ectopic adipose tissue extending from the mesenteric attachment and covering the majority of the small and large intestinal surface. Mesenteric adipose tissue in patients with IBD presents several morphological and functional alterations, e.g., it is more infiltrated with immune cells such as macrophages and T cells. All these lines of evidence clearly show an association between obesity, adipose tissue, and functional bowel disorders. In this review, we will show that the mesenteric adipose tissue and creeping fat are not innocent by standers but actively contribute to the intestinal and systemic inflammatory responses in patients with IBD. More specifically, we will review evidence showing that adipose tissue in IBD is associated with major alterations in the secretion of cytokines and adipokines involved in inflammatory process, in adipose tissue mesenchymal stem cells and adipogenesis, and in the interaction between adipose tissue and other intestinal components (immune, lymphatic, neuroendocrine, and intestinal epithelial systems). Collectively, these studies underline the importance of adipose tissue for the identification of novel therapeutic approaches for IBD.

Biomimetic heterogenous elastic tissue development.

PubMed

Tsai, Kai Jen; Dixon, Simon; Hale, Luke Richard; Darbyshire, Arnold; Martin, Daniel; de Mel, Achala

2017-01-01

There is an unmet need for artificial tissue to address current limitations with donor organs and problems with donor site morbidity. Despite the success with sophisticated tissue engineering endeavours, which employ cells as building blocks, they are limited to dedicated labs suitable for cell culture, with associated high costs and long tissue maturation times before available for clinical use. Direct 3D printing presents rapid, bespoke, acellular solutions for skull and bone repair or replacement, and can potentially address the need for elastic tissue, which is a major constituent of smooth muscle, cartilage, ligaments and connective tissue that support organs. Thermoplastic polyurethanes are one of the most versatile elastomeric polymers. Their segmented block copolymeric nature, comprising of hard and soft segments allows for an almost limitless potential to control physical properties and mechanical behaviour. Here we show direct 3D printing of biocompatible thermoplastic polyurethanes with Fused Deposition Modelling, with a view to presenting cell independent in-situ tissue substitutes. This method can expeditiously and economically produce heterogenous, biomimetic elastic tissue substitutes with controlled porosity to potentially facilitate vascularisation. The flexibility of this application is shown here with tubular constructs as exemplars. We demonstrate how these 3D printed constructs can be post-processed to incorporate bioactive molecules. This efficacious strategy, when combined with the privileges of digital healthcare, can be used to produce bespoke elastic tissue substitutes in-situ, independent of extensive cell culture and may be developed as a point-of-care therapy approach.

Self-Organization and the Self-Assembling Process in Tissue Engineering

PubMed Central

Eswaramoorthy, Rajalakshmanan; Hadidi, Pasha; Hu, Jerry C.

2015-01-01

In recent years, the tissue engineering paradigm has shifted to include a new and growing subfield of scaffoldless techniques which generate self-organizing and self-assembling tissues. This review aims to provide a cogent description of this relatively new research area, with special emphasis on applications toward clinical use and research models. Particular emphasis is placed on providing clear definitions of self-organization and the self-assembling process, as delineated from other scaffoldless techniques in tissue engineering and regenerative medicine. Significantly, during formation, self-organizing and self-assembling tissues display biological processes similar to those that occur in vivo. These help lead to the recapitulation of native tissue morphological structure and organization. Notably, functional properties of these tissues also approach native tissue values; some of these engineered tissues are already in clinical trials. This review aims to provide a cohesive summary of work in this field, and to highlight the potential of self-organization and the self-assembling process to provide cogent solutions to current intractable problems in tissue engineering. PMID:23701238

Isolation of Precursor Cells from Waste Solid Fat Tissue

NASA Technical Reports Server (NTRS)

Byerly, Diane; Sognier, Marguerite A.

2009-01-01

A process for isolating tissue-specific progenitor cells exploits solid fat tissue obtained as waste from such elective surgical procedures as abdominoplasties (tummy tucks) and breast reductions. Until now, a painful and risky process of aspiration of bone marrow has been used to obtain a limited number of tissue- specific progenitor cells. The present process yields more tissue-specific progenitor cells and involves much less pain and risk for the patient. This process includes separation of fat from skin, mincing of the fat into small pieces, and forcing a fat saline mixture through a sieve. The mixture is then digested with collagenase type I in an incubator. After centrifugation tissue-specific progenitor cells are recovered and placed in a tissue-culture medium in flasks or Petri dishes. The tissue-specific progenitor cells can be used for such purposes as (1) generating three-dimensional tissue equivalent models for studying bone loss and muscle atrophy (among other deficiencies) and, ultimately, (2) generating replacements for tissues lost by the fat donor because of injury or disease.

Nutritional programming of disease: unravelling the mechanism

PubMed Central

Langley-Evans, Simon C

2009-01-01

Nutritional programming is the process through which variation in the quality or quantity of nutrients consumed during pregnancy exerts permanent effects upon the developing fetus. Programming of fetal development is considered to be an important risk factor for non-communicable diseases of adulthood, including coronary heart disease and other disorders related to insulin resistance. The study of programming in relation to disease processes has been advanced by development of animal models, which have utilized restriction or over-feeding of specific nutrients in either rodents or sheep. These consistently demonstrate the biological plausibility of the nutritional programming hypothesis and, importantly, provide tools with which to examine the mechanisms through which programming may occur. Studies of animals subject to undernutrition in utero generally exhibit changes in the structure of key organs such as the kidney, heart and brain. These appear consistent with remodelling of development, associated with disruption of cellular proliferation and differentiation. Whilst the causal pathways which extend from this tissue remodelling to disease can be easily understood, the processes which lead to this disordered organ development are poorly defined. Even minor variation in maternal nutritional status is capable of producing important shifts in the fetal environment. It is suggested that these environmental changes are associated with altered expression of key genes, which are responsible for driving the tissue remodelling response and future disease risk. Nutrition-related factors may drive these processes by disturbing placental function, including control of materno-fetal endocrine exchanges, or the epigenetic regulation of gene expression. PMID:19175805

Processing highly porous calcium phosphate ceramics for use in bioreactor cores for culturing human liver cells in-vitro

NASA Astrophysics Data System (ADS)

Finoli, Anthony

Chronic liver disease is the 11th highest cause of death in the United States claiming over 30,000 lives in 2009. The current treatment for chronic liver failure is liver transplantation but the availability of tissue is far less than the number of patients in need. To develop human liver tissue in the lab a 3D culturing environment must be created to support the growth of a complex tissue. Hydroxyapatite (HAp) has been chosen as a scaffold material because of its biocompatibility in the body and the ability to create a bioresorbable scaffold. By using a ceramic material, it is possible to create a three dimensional, protective environment in which tissue can grow. The first part of this study is to examine the behavior of adult human liver cells grown on composites of HAp and different biocompatible hydrogels. Porous HAp has been created using an emulsion foaming technique and cells are injected into the structure after being suspended in a hydrogel and are kept in culture for up to 28 days. Functional assays, gene expression and fluorescent microscopy will be used to examine these cultures. The second part of this study will be to develop a processing technique to create a resorbable scaffold that incorporates a vascular system template. Previous experiments have shown the high temperature decomposition of HAp into resorbable calcium phosphates will be used to create a multiphase material. By controlling the amount of transformation product formed, it is proposed that the resorption of the scaffold can be tailored. To introduce a pore network to guide the growth of a vascular system, a positive-negative casting technique has also been developed. A positive polymer copy can be made of a natural vascular system and ceramic is foamed around the copy. During sintering, the polymer is pyrolyzed leaving a multiscale pore network in the ceramic. By combining these techniques, it is proposed that a calcium phosphate bioreactor core can be processed that is suitable for the culturing of human liver tissue.

In vitro 3D regeneration-like growth of human patient brain tissue.

PubMed

Tang-Schomer, M D; Wu, W B; Kaplan, D L; Bookland, M J

2018-05-01

In vitro culture of primary neurons is widely adapted with embryonic but not mature brain tissue. Here, we extended a previously developed bioengineered three-dimensional (3D) embryonic brain tissue model to resected normal patient brain tissue in an attempt to regenerate human neurons in vitro. Single cells and small sized (diameter < 100 μm) spheroids from dissociated brain tissue were seeded into 3D silk fibroin-based scaffolds, with or without collagen or Matrigel, and compared with two-dimensional cultures and scaffold-free suspension cultures. Changes of cell phenotypes (neuronal, astroglial, neural progenitor, and neuroepithelial) were quantified with flow cytometry and analyzed with a new method of statistical analysis specifically designed for percentage comparison. Compared with a complete lack of viable cells in conventional neuronal cell culture condition, supplements of vascular endothelial growth factor-containing pro-endothelial cell condition led to regenerative growth of neurons and astroglial cells from "normal" human brain tissue of epilepsy surgical patients. This process involved delayed expansion of Nestin+ neural progenitor cells, emergence of TUJ1+ immature neurons, and Vimentin+ neuroepithelium-like cell sheet formation in prolonged cultures (14 weeks). Micro-tissue spheroids, but not single cells, supported the brain tissue growth, suggesting importance of preserving native cell-cell interactions. The presence of 3D scaffold, but not hydrogel, allowed for Vimentin+ cell expansion, indicating a different growth mechanism than pluripotent cell-based brain organoid formation. The slow and delayed process implied an origin of quiescent neural precursors in the neocortex tissue. Further optimization of the 3D tissue model with primary human brain cells could provide personalized brain disease models. Copyright © 2018 John Wiley & Sons, Ltd.

Brassica napus seed endosperm - metabolism and signaling in a dead end tissue.

PubMed

Lorenz, Christin; Rolletschek, Hardy; Sunderhaus, Stephanie; Braun, Hans-Peter

2014-08-28

Oilseeds are an important element of human nutrition and of increasing significance for the production of industrial materials. The development of the seeds is based on a coordinated interplay of the embryo and its surrounding tissue, the endosperm. This study aims to give insights into the physiological role of endosperm for seed development in the oilseed crop Brassica napus. Using protein separation by two-dimensional (2D) isoelectric focusing (IEF)/SDS polyacrylamide gel electrophoresis (PAGE) and protein identification by mass spectrometry three proteome projects were carried out: (i) establishment of an endosperm proteome reference map, (ii) proteomic characterization of endosperm development and (iii) comparison of endosperm and embryo proteomes. The endosperm proteome reference map comprises 930 distinct proteins, including enzymes involved in genetic information processing, carbohydrate metabolism, environmental information processing, energy metabolism, cellular processes and amino acid metabolism. To investigate dynamic changes in protein abundance during seed development, total soluble proteins were extracted from embryo and endosperm fractions at defined time points. Proteins involved in sugar converting and recycling processes, ascorbate metabolism, amino acid biosynthesis and redox balancing were found to be of special importance for seed development in B. napus. Implications for the seed filling process and the function of the endosperm for seed development are discussed. The endosperm is of key importance for embryo development during seed formation in plants. We present a broad study for characterizing endosperm proteins in the oilseed plant B. napus. Furthermore, a project on the biochemical interplay between the embryo and the endosperm during seed development is presented. We provide evidence that the endosperm includes a complete set of enzymes necessary for plant primary metabolism. Combination of our results with metabolome data will further improve systems-level understanding of the seed filling process and provide rational strategies for plant bioengineering. Copyright © 2014 Elsevier B.V. All rights reserved.

Regulated Proteolytic Processing of Reelin through Interplay of Tissue Plasminogen Activator (tPA), ADAMTS-4, ADAMTS-5, and Their Modulators

PubMed Central

Krstic, Dimitrije; Rodriguez, Myriam; Knuesel, Irene

2012-01-01

The extracellular signaling protein Reelin, indispensable for proper neuronal migration and cortical layering during development, is also expressed in the adult brain where it modulates synaptic functions. It has been shown that proteolytic processing of Reelin decreases its signaling activity and promotes Reelin aggregation in vitro, and that proteolytic processing is affected in various neurological disorders, including Alzheimer's disease (AD). However, neither the pathophysiological significance of dysregulated Reelin cleavage, nor the involved proteases and their modulators are known. Here we identified the serine protease tissue plasminogen activator (tPA) and two matrix metalloproteinases, ADAMTS-4 and ADAMTS-5, as Reelin cleaving enzymes. Moreover, we assessed the influence of several endogenous protease inhibitors, including tissue inhibitors of metalloproteinases (TIMPs), α-2-Macroglobulin, and multiple serpins, as well as matrix metalloproteinase 9 (MMP-9) on Reelin cleavage, and described their complex interplay in the regulation of this process. Finally, we could demonstrate that in the murine hippocampus, the expression levels and localization of Reelin proteases largely overlap with that of Reelin. While this pattern remained stable during normal aging, changes in their protein levels coincided with accelerated Reelin aggregation in a mouse model of AD. PMID:23082219

Summary of: Regenerative endodontics.

PubMed

Clark, Stephen J

2014-03-01

Significant advances in our understanding of the biological processes involved in tooth development and repair at the cellular and molecular levels have underpinned the newly emerging area of regenerative endodontics. Development of treatment protocols based on exploiting the natural wound healing properties of the dental pulp and applying tissue engineering principles has allowed reporting of case series showing preservation of tissue vitality and apexogenesis. To review current case series reporting regenerative endodontics. Current treatment approaches tend to stimulate more reparative than regenerative responses in respect of the new tissue generated, which often does not closely resemble the physiological structure of dentine-pulp. However, despite these biological limitations, such techniques appear to offer significant promise for improved treatment outcomes. Improved biological outcomes will likely emerge from the many experimental studies being reported and will further contribute to improvements in clinical treatment protocols.

Noninvasive Spatially Offset and Transmission Raman Mapping of Breast Tissue: A Multimodal Approach toward the in Vivo Assessment of Tissue Pathology

DTIC Science & Technology

2012-04-01

in breast cancer clinical practice and research to independently develop a new technology from a concept. My learning objectives include the...o ........... ...,. of laur .........,. ~: (1) tluo .. ,.. data ..... at I(,,II,P), (1) the raw valu. ot tluo tam %. polnla 1(..,, v, Ill) OJUIJ...technology (PAT) tool for the in-line monitoring and understanding of a powder blending process. ]oumtd of Phannaceu.tical and Biumedical Antdysis, 48

Wound-Healing Studies in Cornea and Skin: Parallels, Differences and Opportunities

PubMed Central

Bukowiecki, Anne; Hos, Deniz; Cursiefen, Claus; Eming, Sabine A.

2017-01-01

The cornea and the skin are both organs that provide the outer barrier of the body. Both tissues have developed intrinsic mechanisms that protect the organism from a wide range of external threats, but at the same time also enable rapid restoration of tissue integrity and organ-specific function. The easy accessibility makes the skin an attractive model system to study tissue damage and repair. Findings from skin research have contributed to unravelling novel fundamental principles in regenerative biology and the repair of other epithelial-mesenchymal tissues, such as the cornea. Following barrier disruption, the influx of inflammatory cells, myofibroblast differentiation, extracellular matrix synthesis and scar formation present parallel repair mechanisms in cornea and skin wound healing. Yet, capillary sprouting, while pivotal in proper skin wound healing, is a process that is rather associated with pathological repair of the cornea. Understanding the parallels and differences of the cellular and molecular networks that coordinate the wound healing response in skin and cornea are likely of mutual importance for both organs with regard to the development of regenerative therapies and understanding of the disease pathologies that affect epithelial-mesenchymal interactions. Here, we review the principal events in corneal wound healing and the mechanisms to restore corneal transparency and barrier function. We also refer to skin repair mechanisms and their potential implications for regenerative processes in the cornea. PMID:28604651

Cytomics - importance of multimodal analysis of cell function and proliferation in oncology.

PubMed

Tárnok, A; Bocsi, J; Brockhoff, G

2006-12-01

Cancer is a highly complex and heterogeneous disease involving a succession of genetic changes (frequently caused or accompanied by exogenous trauma), and resulting in a molecular phenotype that in turn results in a malignant specification. The development of malignancy has been described as a multistep process involving self-sufficiency in growth signals, insensitivity to antigrowth signals, evasion of apoptosis, limitless replicative potential, sustained angiogenesis, and finally tissue invasion and metastasis. The quantitative analysis of networking molecules within the cells might be applied to understand native-state tissue signalling biology, complex drug actions and dysfunctional signalling in transformed cells, that is, in cancer cells. High-content and high-throughput single-cell analysis can lead to systems biology and cytomics. The application of cytomics in cancer research and diagnostics is very broad, ranging from the better understanding of the tumour cell biology to the identification of residual tumour cells after treatment, to drug discovery. The ultimate goal is to pinpoint in detail these processes on the molecular, cellular and tissue level. A comprehensive knowledge of these will require tissue analysis, which is multiplex and functional; thus, vast amounts of data are being collected from current genomic and proteomic platforms for integration and interpretation as well as for new varieties of updated cytomics technology. This overview will briefly highlight the most important aspects of this continuously developing field.

Development and Validation of an Inductively Coupled Plasma Mass Spectrometry (ICP-MS) Method for Quantitative Analysis of Platinum in Plasma, Urine, and Tissues.

PubMed

Zhang, Ti; Cai, Shuang; Forrest, Wai Chee; Mohr, Eva; Yang, Qiuhong; Forrest, M Laird

2016-09-01

Cisplatin, a platinum chemotherapeutic, is one of the most commonly used chemotherapeutic agents for many solid tumors. In this work, we developed and validated an inductively coupled plasma mass spectrometry (ICP-MS) method for quantitative determination of platinum levels in rat urine, plasma, and tissue matrices including liver, brain, lungs, kidney, muscle, heart, spleen, bladder, and lymph nodes. The tissues were processed using a microwave accelerated reaction system (MARS) system prior to analysis on an Agilent 7500 ICP-MS. According to the Food and Drug Administration guidance for industry, bioanalytical validation parameters of the method, such as selectivity, accuracy, precision, recovery, and stability were evaluated in rat biological samples. Our data suggested that the method was selective for platinum without interferences caused by other presenting elements, and the lower limit of quantification was 0.5 ppb. The accuracy and precision of the method were within 15% variation and the recoveries of platinum for all tissue matrices examined were determined to be 85-115% of the theoretical values. The stability of the platinum-containing solutions, including calibration standards, stock solutions, and processed samples in rat biological matrices was investigated. Results indicated that the samples were stable after three cycles of freeze-thaw and for up to three months. © The Author(s) 2016.

Development and Validation of an Inductively Coupled Plasma Mass Spectrometry (ICP-MS) Method for Quantitative Analysis of Platinum in Plasma, Urine, and Tissues

PubMed Central

Zhang, Ti; Cai, Shuang; Forrest, Wai Chee; Mohr, Eva; Yang, Qiuhong; Forrest, M. Laird

2016-01-01

Cisplatin, a platinum chemotherapeutic, is one of the most commonly used chemotherapeutic agents for many solid tumors. In this work, we developed and validated an inductively coupled plasma mass spectrometry (ICP-MS) method for quantitative determination of platinum levels in rat urine, plasma, and tissue matrices including liver, brain, lungs, kidney, muscle, heart, spleen, bladder, and lymph nodes. The tissues were processed using a microwave accelerated reaction system (MARS) system prior to analysis on an Agilent 7500 ICP-MS. According to the Food and Drug Administration guidance for industry, bioanalytical validation parameters of the method, such as selectivity, accuracy, precision, recovery, and stability were evaluated in rat biological samples. Our data suggested that the method was selective for platinum without interferences caused by other presenting elements, and the lower limit of quantification was 0.5 ppb. The accuracy and precision of the method were within 15% variation and the recoveries of platinum for all tissue matrices examined were determined to be 85–115% of the theoretical values. The stability of the platinum-containing solutions, including calibration standards, stock solutions, and processed samples in rat biological matrices was investigated. Results indicated that the samples were stable after three cycles of freeze–thaw and for up to three months. PMID:27527103

The Circadian Clock in Cancer Development and Therapy

PubMed Central

Fu, Loning; Kettner, Nicole M.

2014-01-01

Most aspects of mammalian function display circadian rhythms driven by an endogenous clock. The circadian clock is operated by genes and comprises a central clock in the brain that responds to environmental cues and controls subordinate clocks in peripheral tissues via circadian output pathways. The central and peripheral clocks coordinately generate rhythmic gene expression in a tissue-specific manner in vivo to couple diverse physiological and behavioral processes to periodic changes in the environment. However, as the world industrialized, activities that disrupt endogenous homeostasis with external circadian cues have increased. This change in lifestyle has been linked to increased risk of diseases in all aspects of human health, including cancer. Studies in humans and animal models have revealed that cancer development in vivo is closely associated with the loss of circadian homeostasis in energy balance, immune function and aging that are supported by cellular functions important for tumor suppression including cell proliferation, senescence, metabolism and DNA damage response. The clock controls these cellular functions both locally in cells of peripheral tissues and at the organismal level via extracellular signaling. Thus, the hierarchical mammalian circadian clock provides a unique system to study carcinogenesis as a deregulated physiological process in vivo. The asynchrony between host and malignant tissues in cell proliferation and metabolism also provides new and exciting options for novel anti-cancer therapies. PMID:23899600

Development of a penetration friction apparatus (PFA) to measure the frictional performance of surgical suture.

PubMed

Zhang, Gangqiang; Ren, Tianhui; Lette, Walter; Zeng, Xiangqiong; van der Heide, Emile

2017-10-01

Nowadays there is a wide variety of surgical sutures available in the market. Surgical sutures have different sizes, structures, materials and coatings, whereas they are being used for various surgeries. The frictional performances of surgical sutures have been found to play a vital role in their functionality. The high friction force of surgical sutures in the suturing process may cause inflammation and pain to the person, leading to a longer recovery time, and the second trauma of soft or fragile tissue. Thus, the investigation into the frictional performance of surgical suture is essential. Despite the unquestionable fact, little is actually known on the friction performances of surgical suture-tissue due to the lack of appropriate test equipment. This study presents a new penetration friction apparatus (PFA) that allowed for the evaluation of the friction performances of various surgical needles and sutures during the suturing process, under different contact conditions. It considered the deformation of tissue and can realize the puncture force measurements of surgical needles as well as the friction force of surgical sutures. The developed PFA could accurately evaluate and understand the frictional behaviour of surgical suture-tissue in the simulating clinical conditions. The forces measured by the PFA showed the same trend as that reported in literatures. Copyright © 2017 Elsevier Ltd. All rights reserved.

Wound-Healing Studies in Cornea and Skin: Parallels, Differences and Opportunities.

PubMed

Bukowiecki, Anne; Hos, Deniz; Cursiefen, Claus; Eming, Sabine A

2017-06-12

The cornea and the skin are both organs that provide the outer barrier of the body. Both tissues have developed intrinsic mechanisms that protect the organism from a wide range of external threats, but at the same time also enable rapid restoration of tissue integrity and organ-specific function. The easy accessibility makes the skin an attractive model system to study tissue damage and repair. Findings from skin research have contributed to unravelling novel fundamental principles in regenerative biology and the repair of other epithelial-mesenchymal tissues, such as the cornea. Following barrier disruption, the influx of inflammatory cells, myofibroblast differentiation, extracellular matrix synthesis and scar formation present parallel repair mechanisms in cornea and skin wound healing. Yet, capillary sprouting, while pivotal in proper skin wound healing, is a process that is rather associated with pathological repair of the cornea. Understanding the parallels and differences of the cellular and molecular networks that coordinate the wound healing response in skin and cornea are likely of mutual importance for both organs with regard to the development of regenerative therapies and understanding of the disease pathologies that affect epithelial-mesenchymal interactions. Here, we review the principal events in corneal wound healing and the mechanisms to restore corneal transparency and barrier function. We also refer to skin repair mechanisms and their potential implications for regenerative processes in the cornea.

Spatial development of transport structures in apple (Malus × domestica Borkh.) fruit

PubMed Central

Herremans, Els; Verboven, Pieter; Hertog, Maarten L. A. T. M.; Cantre, Dennis; van Dael, Mattias; De Schryver, Thomas; Van Hoorebeke, Luc; Nicolaï, Bart M.

2015-01-01

The void network and vascular system are important pathways for the transport of gases, water and solutes in apple fruit (Malus × domestica Borkh). Here we used X-ray micro-tomography at various spatial resolutions to investigate the growth of these transport structures in 3D during fruit development of “Jonagold” apple. The size of the void space and porosity in the cortex tissue increased considerably. In the core tissue, the porosity was consistently lower, and seemed to decrease toward the end of the maturation period. The voids in the core were more narrow and fragmented than the voids in the cortex. Both the void network in the core and in the cortex changed significantly in terms of void morphology. An automated segmentation protocol underestimated the total vasculature length by 9–12% in comparison to manually processed images. Vascular networks increased in length from a total of 5 m at 9 weeks after full bloom, to more than 20 m corresponding to 5 cm of vascular tissue per cubic centimeter of apple tissue. A high degree of branching in both the void network and vascular system and a complex three-dimensional pattern was observed across the whole fruit. The 3D visualizations of the transport structures may be useful for numerical modeling of organ growth and transport processes in fruit. PMID:26388883

ENERGY SYSTEM DEVELOPMENT AND LOAD MANAGEMENT THROUGH THE REHABILITATION AND RETURN TO PLAY PROCESS.

PubMed

Morrison, Scot; Ward, Patrick; duManoir, Gregory R

2017-08-01

Return-to-play from injury is a complex process involving many factors including the balancing of tissue healing rates with the development of biomotor abilities. This process requires interprofessional cooperation to ensure success. An often-overlooked aspect of return-to-play is the development and maintenance of sports specific conditioning while monitoring training load to ensure that the athlete's training stimulus over the rehabilitation period is appropriate to facilitate a successful return to play. The purpose of this clinical commentary is to address the role of energy systems training as part of the return-to-play process. Additionally the aim is to provide practitioners with an overview of practical sports conditioning training methods and monitoring strategies to allow them to direct and quantify the return-to-play process. 5.

Transplantable tissue growth-a commercial space venture

NASA Astrophysics Data System (ADS)

Giuntini, Ronald E.; Vardaman, William K.

1997-01-01

Rantek was incorporated in 1984 to pursue research toward product development in space based biotechnology. The company has maintained an aggressive experiment flight program since 1989 having flown biotechnology experiments in six Consort rockets flights, one Joust rocket flight and eight Space Shuttle missions. The objective of these flights was to conduct a series of research experiments to resolve issues affecting transplantable tissue growth feasibility. The purpose of the flight research was to determine the behavior of lymphocyte mixing, activation, magnetic mixing and process control, drug studies in a model leukemia cell line, and various aspects of the hardware system process control in the low gravity of space. The company is now preparing for a two Space Shuttle flight program as precursors to a sustained, permanent, commercial venture at the Space Station. The shuttle flights will enable new, larger scale tissue growth systems to be tested to determine fundamental process control sensitivity and growth rates unique to a number of tissue types. The answer to these issues will ultimately determine the commercial viability of the Rantek Biospace program. This paper addresses considerations that will drive the cost of a space venture-the largest cost driver will be the cost to and from the station and the cost at the station.

Mammalian cell models to advance our understanding of wound healing: a review.

PubMed

Vidmar, Jerneja; Chingwaru, Constance; Chingwaru, Walter

2017-04-01

Rapid and efficient healing of damaged tissue is critical for the restoration of tissue function and avoidance of tissue defects. Many in vitro cell models have been described for wound healing studies; however, the mechanisms that underlie the process, especially in chronic or complicated wounds, are not fully understood. The identification of cell culture systems that closely simulate the physiology of damaged tissue in vivo is necessary. We describe the cell culture models that have enhanced our understanding, this far, of the wound healing process or have been used in drug discovery. Cell cultures derived from the epithelium, including corneal, renal, intestinal (IEC-8 cells and IEC-6), skin epithelial cells (keratinocytes, fibroblasts, and multipotent mesenchymal stem cells), and the endothelium (human umbilical vein endothelial cells, primary mouse endothelial cells, endodermal stem cells, human mesenchymal stem cells, and corneal endothelial cells) have played a pivotal role toward our understanding of the mechanisms of wound healing. More studies are necessary to develop co-culture cell models which closely simulate the environment of a wound in vivo. Cell culture models are invaluable tools to promote our understanding of the mechanisms that regulate the wound healing process and provide a platform for drug discovery. Copyright © 2016 Elsevier Inc. All rights reserved.

Morphologic differentiation of colon carcinoma cell lines HT-29 and HT-29KM in rotating-wall vessels

NASA Technical Reports Server (NTRS)

Goodwin, T. J.; Jessup, J. M.; Wolf, D. A.

1992-01-01

A new low shear stress microcarrier culture system has been developed at NASA's Johnson Space Center that permits three-dimensional tissue culture. Two established human colon adenocarcinoma cell lines, HT-29, an undifferentiated, and HT-29KM, a stable, moderately differentiated subline of HT-29, were grown in new tissue culture bioreactors called Rotating-Wall Vessels (RWVs). RWVs are used in conjunction with multicellular cocultivation to develop a unique in vitro tissue modeling system. Cells were cultivated on Cytodex-3 microcarrier beads, with and without mixed normal human colonic fibroblasts, which served as the mesenchymal layer. Culture of the tumor lines in the absence of fibroblasts produced spheroidlike growth and minimal differentiation. In contrast, when tumor lines were co-cultivated with normal colonic fibroblasts, initial growth was confined to the fibroblast population until the microcarriers were covered. The tumor cells then commenced proliferation at an accelerated rate, organizing themselves into three-dimensional tissue masses that achieved 1.0- to 1.5-cm diameters. The masses displayed glandular structures, apical and internal glandular microvilli, tight intercellular junctions, desmosomes, cellular polarity, sinusoid development, internalized mucin, and structural organization akin to normal colon crypt development. Differentiated samples were subjected to transmission and scanning electron microscopy and histologic analysis, revealing embryoniclike mesenchymal cells lining the areas around the growth matrices. Necrosis was minimal throughout the tissue masses. These data suggest that the RWV affords a new model for investigation and isolation of growth, regulatory, and structural processes within neoplastic and normal tissue.

Quantifying Three-Dimensional Morphology and RNA from Individual Embryos

PubMed Central

Green, Rebecca M.; Leach, Courtney L.; Hoehn, Natasha; Marcucio, Ralph S.; Hallgrímsson, Benedikt

2017-01-01

Quantitative analysis of morphogenesis aids our understanding of developmental processes by providing a method to link changes in shape with cellular and molecular processes. Over the last decade many methods have been developed for 3D imaging of embryos using microCT scanning to quantify the shape of embryos during development. These methods generally involve a powerful, cross-linking fixative such as paraformaldehyde to limit shrinkage during the CT scan. However, the extended time frames that these embryos are incubated in such fixatives prevent use of the tissues for molecular analysis after microCT scanning. This is a significant problem because it limits the ability to correlate variation in molecular data with morphology at the level of individual embryos. Here, we outline a novel method that allows RNA, DNA or protein isolation following CT scan while also allowing imaging of different tissue layers within the developing embryo. We show shape differences early in craniofacial development (E11.5) between common mouse genetic backgrounds, and demonstrate that we are able to generate RNA from these embryos after CT scanning that is suitable for downstream RT-PCR and RNAseq analyses. PMID:28152580

Self-Organization of Stem Cell Colonies and of Early Mammalian Embryos: Recent Experiments Shed New Light on the Role of Autonomy vs. External Instructions in Basic Body Plan Development

PubMed Central

Denker, Hans-Werner

2016-01-01

“Organoids”, i.e., complex structures that can develop when pluripotent or multipotent stem cells are maintained in three-dimensional cultures, have become a new area of interest in stem cell research. Hopes have grown that when focussing experimentally on the mechanisms behind this type of in vitro morphogenesis, research aiming at tissue and organ replacements can be boosted. Processes leading to the formation of organoids in vitro are now often addressed as self-organization, a term referring to the formation of complex tissue architecture in groups of cells without depending on specific instruction provided by other cells or tissues. The present article focuses on recent reports using the term self-organization in the context of studies on embryogenesis, specifically addressing pattern formation processes in human blastocysts attaching in vitro, or in colonies of pluripotent stem cells (“gastruloids”). These morphogenetic processes are of particular interest because, during development in vivo, they lead to basic body plan formation and individuation. Since improved methodologies like those employed by the cited authors became available, early embryonic pattern formation/self-organization appears to evolve now as a research topic of its own. This review discusses concepts concerning the involved mechanisms, focussing on autonomy of basic body plan development vs. dependence on external signals, as possibly provided by implantation in the uterus, and it addresses biological differences between an early mammalian embryo, e.g., a morula, and a cluster of pluripotent stem cells. It is concluded that, apart from being of considerable biological interest, the described type of research needs to be contemplated carefully with regard to ethical implications when performed with human cells. PMID:27792143

Self-Organization of Stem Cell Colonies and of Early Mammalian Embryos: Recent Experiments Shed New Light on the Role of Autonomy vs. External Instructions in Basic Body Plan Development.

PubMed

Denker, Hans-Werner

2016-10-25

" Organoids ", i.e., complex structures that can develop when pluripotent or multipotent stem cells are maintained in three-dimensional cultures, have become a new area of interest in stem cell research. Hopes have grown that when focussing experimentally on the mechanisms behind this type of in vitro morphogenesis, research aiming at tissue and organ replacements can be boosted. Processes leading to the formation of organoids in vitro are now often addressed as self-organization , a term referring to the formation of complex tissue architecture in groups of cells without depending on specific instruction provided by other cells or tissues. The present article focuses on recent reports using the term self-organization in the context of studies on embryogenesis , specifically addressing pattern formation processes in human blastocysts attaching in vitro, or in colonies of pluripotent stem cells (" gastruloids "). These morphogenetic processes are of particular interest because, during development in vivo, they lead to basic body plan formation and individuation. Since improved methodologies like those employed by the cited authors became available, early embryonic pattern formation/self-organization appears to evolve now as a research topic of its own. This review discusses concepts concerning the involved mechanisms, focussing on autonomy of basic body plan development vs. dependence on external signals, as possibly provided by implantation in the uterus, and it addresses biological differences between an early mammalian embryo, e.g., a morula, and a cluster of pluripotent stem cells. It is concluded that, apart from being of considerable biological interest, the described type of research needs to be contemplated carefully with regard to ethical implications when performed with human cells.

Mechanical forces as information: an integrated approach to plant and animal development

PubMed Central

Hernández-Hernández, Valeria; Rueda, Denisse; Caballero, Lorena; Alvarez-Buylla, Elena R.; Benítez, Mariana

2014-01-01

Mechanical forces such as tension and compression act throughout growth and development of multicellular organisms. These forces not only affect the size and shape of the cells and tissues but are capable of modifying the expression of genes and the localization of molecular components within the cell, in the plasma membrane, and in the plant cell wall. The magnitude and direction of these physical forces change with cellular and tissue properties such as elasticity. Thus, mechanical forces and the mesoscopic fields that emerge from their local action constitute important sources of positional information. Moreover, physical and biochemical processes interact in non-linear ways during tissue and organ growth in plants and animals. In this review we discuss how such mechanical forces are generated, transmitted, and sensed in these two lineages of multicellular organisms to yield long-range positional information. In order to do so we first outline a potentially common basis for studying patterning and mechanosensing that relies on the structural principle of tensegrity, and discuss how tensegral structures might arise in plants and animals. We then provide some examples of morphogenesis in which mechanical forces appear to act as positional information during development, offering a possible explanation for ubiquitous processes, such as the formation of periodic structures. Such examples, we argue, can be interpreted in terms of tensegral phenomena. Finally, we discuss the hypothesis of mechanically isotropic points as a potentially generic mechanism for the localization and maintenance of stem-cell niches in multicellular organisms. This comparative approach aims to help uncovering generic mechanisms of morphogenesis and thus reach a better understanding of the evolution and development of multicellular phenotypes, focusing on the role of physical forces in these processes. PMID:24959170

Mechanical forces as information: an integrated approach to plant and animal development.

PubMed

Hernández-Hernández, Valeria; Rueda, Denisse; Caballero, Lorena; Alvarez-Buylla, Elena R; Benítez, Mariana

2014-01-01

Mechanical forces such as tension and compression act throughout growth and development of multicellular organisms. These forces not only affect the size and shape of the cells and tissues but are capable of modifying the expression of genes and the localization of molecular components within the cell, in the plasma membrane, and in the plant cell wall. The magnitude and direction of these physical forces change with cellular and tissue properties such as elasticity. Thus, mechanical forces and the mesoscopic fields that emerge from their local action constitute important sources of positional information. Moreover, physical and biochemical processes interact in non-linear ways during tissue and organ growth in plants and animals. In this review we discuss how such mechanical forces are generated, transmitted, and sensed in these two lineages of multicellular organisms to yield long-range positional information. In order to do so we first outline a potentially common basis for studying patterning and mechanosensing that relies on the structural principle of tensegrity, and discuss how tensegral structures might arise in plants and animals. We then provide some examples of morphogenesis in which mechanical forces appear to act as positional information during development, offering a possible explanation for ubiquitous processes, such as the formation of periodic structures. Such examples, we argue, can be interpreted in terms of tensegral phenomena. Finally, we discuss the hypothesis of mechanically isotropic points as a potentially generic mechanism for the localization and maintenance of stem-cell niches in multicellular organisms. This comparative approach aims to help uncovering generic mechanisms of morphogenesis and thus reach a better understanding of the evolution and development of multicellular phenotypes, focusing on the role of physical forces in these processes.

Assessment of bioburden on human and animal tissues: part 2--results of testing of human tissue and qualification of a composite sample for routine bioburden determination.

PubMed

Kowalski, John B; Merritt, Karen; Gocke, David; Osborne, Joel

2012-08-01

A quantitative method was developed and validated to assess bioburden on tissue from human donors and to compare bioburden determination results to swab culture results from the same donor. An initial study with allograft tissue from 101 donors showed a wide range of bioburden levels; values from no colony-forming units (CFU) detected to >28,000 CFU were observed. Tissues from donors that had swab cultures negative for objectionable microorganisms generally had lower bioburden than tissues from donors where objectionable microorganisms were recovered by swab culturing. In a follow-up study with 1,445 donors, a wide range of bioburden levels was again observed on tissues from donors that were swab culture negative for objectionable microorganisms. Tissues from 885 (61%) of these donors had no recoverable bioburden (<2 CFU). Importantly, tissues from 560 (39%) of the donors had recoverable bioburden which ranged from 1 to >24,000 CFU. Identification of bioburden isolates showed a diversity of genera and species. In compliance with the recent revision of the American Association of Tissue Banks K2.210 Standard, the quantitative bioburden determination method was validated with a composite tissue sample that contains bone and soft tissue sections tested together in one extraction vessel. A recovery efficiency of 68% was validated and the composite sample was shown to be representative of all of the tissues recovered from a donor. The use of the composite sample in conjunction with the quantitative bioburden determination method will facilitate an accurate assessment of the numbers and types of contaminating microorganisms on allografts prior to disinfection/sterilization. This information will ensure that disinfection/sterilization processes are properly validated and the capability of the overall allograft process is understood on a donor by donor basis.

Altered miRNA processing disrupts brown/white adipocyte determination and associates with lipodystrophy

PubMed Central

Mori, Marcelo A.; Thomou, Thomas; Boucher, Jeremie; Lee, Kevin Y.; Lallukka, Susanna; Kim, Jason K.; Torriani, Martin; Yki-Järvinen, Hannele; Grinspoon, Steven K.; Cypess, Aaron M.; Kahn, C. Ronald

2014-01-01

miRNAs are important regulators of biological processes in many tissues, including the differentiation and function of brown and white adipocytes. The endoribonuclease dicer is a major component of the miRNA-processing pathway, and in adipose tissue, levels of dicer have been shown to decrease with age, increase with caloric restriction, and influence stress resistance. Here, we demonstrated that mice with a fat-specific KO of dicer develop a form of lipodystrophy that is characterized by loss of intra-abdominal and subcutaneous white fat, severe insulin resistance, and enlargement and “whitening” of interscapular brown fat. Additionally, KO of dicer in cultured brown preadipocytes promoted a white adipocyte–like phenotype and reduced expression of several miRNAs. Brown preadipocyte whitening was partially reversed by expression of miR-365, a miRNA known to promote brown fat differentiation; however, introduction of other miRNAs, including miR-346 and miR-362, also contributed to reversal of the loss of the dicer phenotype. Interestingly, fat samples from patients with HIV-related lipodystrophy exhibited a substantial downregulation of dicer mRNA expression. Together, these findings indicate the importance of miRNA processing in white and brown adipose tissue determination and provide a potential link between this process and HIV-related lipodystrophy. PMID:24983316