Biomimetics--using nature to inspire human innovation.

PubMed

Bar-Cohen, Yoseph

2006-03-01

Evolution has resolved many of nature's challenges leading to lasting solutions. Nature has always inspired human achievements and has led to effective materials, structures, tools, mechanisms, processes, algorithms, methods, systems, and many other benefits (Bar-Cohen Y (ed) 2005 Biomimetics-Biologically Inspired Technologies (Boca Raton, FL: CRC Press) pp 1-552). This field, which is known as biomimetics, offers enormous potential for inspiring new capabilities for exciting future technologies. There are numerous examples of biomimetic successes that involve making simple copies, such as the use of fins for swimming. Others examples involved greater mimicking complexity including the mastery of flying that became possible only after the principles of aerodynamics were better understood. Some commercial implementations of biomimetics, including robotic toys and movie subjects, are increasingly appearing and behaving like living creatures. More substantial benefits of biomimetics include the development of prosthetics that closely mimic real limbs and sensory-enhancing microchips that are interfaced with the brain to assist in hearing, seeing and controlling instruments. A review is given of selected areas that were inspired by nature, and an outlook for potential development in biomimetics is presented.

Combined experimental and theoretical study on the reactivity of compounds I and II in horseradish peroxidase biomimetics.

PubMed

Ji, Li; Franke, Alicja; Brindell, Małgorzata; Oszajca, Maria; Zahl, Achim; van Eldik, Rudi

2014-10-27

For the exploration of the intrinsic reactivity of two key active species in the catalytic cycle of horseradish peroxidase (HRP), Compound I (HRP-I) and Compound II (HRP-II), we generated in situ [Fe(IV) O(TMP(+.) )(2-MeIm)](+) and [Fe(IV) O(TMP)(2-MeIm)](0) (TMP=5,10,15,20-tetramesitylporphyrin; 2-MeIm=2-methylimidazole) as biomimetics for HRP-I and HRP-II, respectively. Their catalytic activities in epoxidation, hydrogen abstraction, and heteroatom oxidation reactions were studied in acetonitrile at -15 °C by utilizing rapid-scan UV/Vis spectroscopy. Comparison of the second-order rate constants measured for the direct reactions of the HRP-I and HRP-II mimics with the selected substrates clearly confirmed the outstanding oxidizing capability of the HRP-I mimic, which is significantly higher than that of HRP-II. The experimental study was supported by computational modeling (DFT calculations) of the oxidation mechanism of the selected substrates with the involvement of quartet and doublet HRP-I mimics ((2,4) Cpd I) and the closed-shell triplet spin HRP-II model ((3) Cpd II) as oxidizing species. The significantly lower activation barriers calculated for the oxidation systems involving (2,4) Cpd I than those found for (3) Cpd II are in line with the much higher oxidizing efficiency of the HRP-I mimic proven in the experimental part of the study. In addition, the DFT calculations show that all three reaction types catalyzed by HRP-I occur on the doublet spin surface in an effectively concerted manner, whereas these reactions may proceed in a stepwise mechanism with the HRP-II mimic as oxidant. However, the high desaturation or oxygen rebound barriers during CH bond activation processes by the HRP-II mimic predict a sufficient lifetime for the substrate radical formed through hydrogen abstraction. Thus, the theoretical calculations suggest that the dissociation of the substrate radical may be a more favorable pathway than desaturation or

Evolving application of biomimetic nanostructured hydroxyapatite

PubMed Central

Roveri, Norberto; Iafisco, Michele

2010-01-01

By mimicking Nature, we can design and synthesize inorganic smart materials that are reactive to biological tissues. These smart materials can be utilized to design innovative third-generation biomaterials, which are able to not only optimize their interaction with biological tissues and environment, but also mimic biogenic materials in their functionalities. The biomedical applications involve increasing the biomimetic levels from chemical composition, structural organization, morphology, mechanical behavior, nanostructure, and bulk and surface chemical–physical properties until the surface becomes bioreactive and stimulates cellular materials. The chemical–physical characteristics of biogenic hydroxyapatites from bone and tooth have been described, in order to point out the elective sides, which are important to reproduce the design of a new biomimetic synthetic hydroxyapatite. This review outlines the evolving applications of biomimetic synthetic calcium phosphates, details the main characteristics of bone and tooth, where the calcium phosphates are present, and discusses the chemical–physical characteristics of biomimetic calcium phosphates, methods of synthesizing them, and some of their biomedical applications. PMID:24198477

Biomimetic mineralization of metal-organic frameworks around polysaccharides.

PubMed

Liang, Kang; Wang, Ru; Boutter, Manon; Doherty, Cara M; Mulet, Xavier; Richardson, Joseph J

2017-01-19

Biomimetic mineralization exploits natural biomineralization processes for the design and fabrication of synthetic functional materials. Here, we report for the first time the use of carbohydrates (polysaccharides) for the biomimetic crystallization of metal-organic frameworks. This discovery greatly expands the potential and diversity of biomimetic approaches for the design, synthesis, and functionalization of new bio-metal-organic framework composite materials.

Biomimetics: forecasting the future of science, engineering, and medicine

PubMed Central

Hwang, Jangsun; Jeong, Yoon; Park, Jeong Min; Lee, Kwan Hong; Hong, Jong Wook; Choi, Jonghoon

2015-01-01

Biomimetics is the study of nature and natural phenomena to understand the principles of underlying mechanisms, to obtain ideas from nature, and to apply concepts that may benefit science, engineering, and medicine. Examples of biomimetic studies include fluid-drag reduction swimsuits inspired by the structure of shark’s skin, velcro fasteners modeled on burrs, shape of airplanes developed from the look of birds, and stable building structures copied from the backbone of turban shells. In this article, we focus on the current research topics in biomimetics and discuss the potential of biomimetics in science, engineering, and medicine. Our report proposes to become a blueprint for accomplishments that can stem from biomimetics in the next 5 years as well as providing insight into their unseen limitations. PMID:26388692

Biomimetics: forecasting the future of science, engineering, and medicine.

PubMed

Hwang, Jangsun; Jeong, Yoon; Park, Jeong Min; Lee, Kwan Hong; Hong, Jong Wook; Choi, Jonghoon

2015-01-01

Biomimetics is the study of nature and natural phenomena to understand the principles of underlying mechanisms, to obtain ideas from nature, and to apply concepts that may benefit science, engineering, and medicine. Examples of biomimetic studies include fluid-drag reduction swimsuits inspired by the structure of shark's skin, velcro fasteners modeled on burrs, shape of airplanes developed from the look of birds, and stable building structures copied from the backbone of turban shells. In this article, we focus on the current research topics in biomimetics and discuss the potential of biomimetics in science, engineering, and medicine. Our report proposes to become a blueprint for accomplishments that can stem from biomimetics in the next 5 years as well as providing insight into their unseen limitations.

Calcifying tissue regeneration via biomimetic materials chemistry

PubMed Central

Green, David W.; Goto, Tazuko K.; Kim, Kye-Seong; Jung, Han-Sung

2014-01-01

Materials chemistry is making a fundamental impact in regenerative sciences providing many platforms for tissue development. However, there is a surprising paucity of replacements that accurately mimic the structure and function of the structural fabric of tissues or promote faithful tissue reconstruction. Methodologies in biomimetic materials chemistry have shown promise in replicating morphologies, architectures and functional building blocks of acellular mineralized tissues dentine, enamel and bone or that can be used to fully regenerate them with integrated cell populations. Biomimetic materials chemistry encompasses the two processes of crystal formation and mineralization of crystals into inorganic formations on organic templates. This review will revisit the successes of biomimetics materials chemistry in regenerative medicine, including coccolithophore simulants able to promote in vivo bone formation. In-depth knowledge of biomineralization throughout evolution informs the biomimetic materials chemist of the most effective techniques for regenerative framework construction exemplified via exploitation of liquid crystals (LCs) and complex self-organizing media. Therefore, a new innovative direction would be to create chemical environments that perform reaction–diffusion exchanges as the basis for building complex biomimetic inorganic structures. This has evolved widely in biology, as have LCs, serving as self-organizing templates in pattern formation of structural biomaterials. For instance, a study is highlighted in which artificially fabricated chiral LCs, made from bacteriophages are transformed into a faithful copy of enamel. While chemical-based strategies are highly promising at creating new biomimetic structures there are limits to the degree of complexity that can be generated. Thus, there may be good reason to implement living or artificial cells in ‘morphosynthesis’ of complex inorganic constructs. In the future, cellular construction is

Major intrinsic proteins in biomimetic membranes.

PubMed

Nielsen, Claus Hélix

2010-01-01

Biological membranes define the structural and functional boundaries in living cells and their organelles. The integrity of the cell depends on its ability to separate inside from outside and yet at the same time allow massive transport of matter in and out the cell. Nature has elegantly met this challenge by developing membranes in the form of lipid bilayers in which specialized transport proteins are incorporated. This raises the question: is it possible to mimic biological membranes and create a membrane based sensor and/or separation device? In the development of a biomimetic sensor/separation technology, a unique class of membrane transport proteins is especially interesting-the major intrinsic proteins (MIPs). Generally, MIPs conduct water molecules and selected solutes in and out of the cell while preventing the passage of other solutes, a property critical for the conservation of the cells internal pH and salt concentration. Also known as water channels or aquaporins they are highly efficient membrane pore proteins some of which are capable of transporting water at very high rates up to 10(9) molecules per second. Some MIPs transport other small, uncharged solutes, such as glycerol and other permeants such as carbon dioxide, nitric oxide, ammonia, hydrogen peroxide and the metalloids antimonite, arsenite, silicic and boric acid depending on the effective restriction mechanism of the protein. The flux properties of MIPs thus lead to the question ifMIPs can be used in separation devices or as sensor devices based on, e.g., the selective permeation of metalloids. In principle a MIP based membrane sensor/separation device requires the supporting biomimetic matrix to be virtually impermeable to anything but water or the solute in question. In practice, however, a biomimetic support matrix will generally have finite permeabilities to both electrolytes and non-electrolytes. The feasibility of a biomimetic MIP device thus depends on the relative transport

Biomimetic Materials and Fabrication Approaches for Bone Tissue Engineering.

PubMed

Kim, Hwan D; Amirthalingam, Sivashanmugam; Kim, Seunghyun L; Lee, Seunghun S; Rangasamy, Jayakumar; Hwang, Nathaniel S

2017-12-01

Various strategies have been explored to overcome critically sized bone defects via bone tissue engineering approaches that incorporate biomimetic scaffolds. Biomimetic scaffolds may provide a novel platform for phenotypically stable tissue formation and stem cell differentiation. In recent years, osteoinductive and inorganic biomimetic scaffold materials have been optimized to offer an osteo-friendly microenvironment for the osteogenic commitment of stem cells. Furthermore, scaffold structures with a microarchitecture design similar to native bone tissue are necessary for successful bone tissue regeneration. For this reason, various methods for fabricating 3D porous structures have been developed. Innovative techniques, such as 3D printing methods, are currently being utilized for optimal host stem cell infiltration, vascularization, nutrient transfer, and stem cell differentiation. In this progress report, biomimetic materials and fabrication approaches that are currently being utilized for biomimetic scaffold design are reviewed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Dental Cell Sheet Biomimetic Tooth Bud Model

PubMed Central

Monteiro, Nelson; Smith, Elizabeth E.; Angstadt, Shantel; Zhang, Weibo; Khademhosseini, Ali

2016-01-01

Tissue engineering and regenerative medicine technologies offer promising therapies for both medicine and dentistry. Our long-term goal is to create functional biomimetic tooth buds for eventual tooth replacement in humans. Here, our objective was to create a biomimetic 3D tooth bud model consisting of dental epithelial (DE) – dental mesenchymal (DM) cell sheets (CSs) combined with biomimetic enamel organ and pulp organ layers created using GelMA hydrogels. Pig DE or DM cells seeded on temperature-responsive plates at various cell densities (0.02, 0.114 and 0.228 cells 106/cm2) and cultured for 7, 14 and 21 days were used to generate DE and DM cell sheets, respectively. Dental CSs were combined with GelMA encapsulated DE and DM cell layers to form bioengineered 3D tooth buds. Biomimetic 3D tooth bud constructs were cultured in vitro, or implanted in vivo for 3 weeks. Analyses were performed using micro-CT, H&E staining, polarized light (Pol) microscopy, immunofluorescent (IF) and immunohistochemical (IHC) analyses. H&E, IHC and IF analyses showed that in vitro cultured multilayered DE-DM CSs expressed appropriate tooth marker expression patterns including SHH, BMP2, RUNX2, tenascin and syndecan, which normally direct DE-DM interactions, DM cell condensation, and dental cell differentiation. In vivo implanted 3D tooth bud constructs exhibited mineralized tissue formation of specified size and shape, and SHH, BMP2 and RUNX2and dental cell differentiation marker expression. We propose our biomimetic 3D tooth buds as models to study optimized DE-DM cell interactions leading to functional biomimetic replacement tooth formation. PMID:27565550

Better than Nature: Nicotinamide Biomimetics That Outperform Natural Coenzymes.

PubMed

Knaus, Tanja; Paul, Caroline E; Levy, Colin W; de Vries, Simon; Mutti, Francesco G; Hollmann, Frank; Scrutton, Nigel S

2016-01-27

The search for affordable, green biocatalytic processes is a challenge for chemicals manufacture. Redox biotransformations are potentially attractive, but they rely on unstable and expensive nicotinamide coenzymes that have prevented their widespread exploitation. Stoichiometric use of natural coenzymes is not viable economically, and the instability of these molecules hinders catalytic processes that employ coenzyme recycling. Here, we investigate the efficiency of man-made synthetic biomimetics of the natural coenzymes NAD(P)H in redox biocatalysis. Extensive studies with a range of oxidoreductases belonging to the "ene" reductase family show that these biomimetics are excellent analogues of the natural coenzymes, revealed also in crystal structures of the ene reductase XenA with selected biomimetics. In selected cases, these biomimetics outperform the natural coenzymes. "Better-than-Nature" biomimetics should find widespread application in fine and specialty chemicals production by harnessing the power of high stereo-, regio-, and chemoselective redox biocatalysts and enabling reactions under mild conditions at low cost.

Better than Nature: Nicotinamide Biomimetics That Outperform Natural Coenzymes

PubMed Central

2016-01-01

The search for affordable, green biocatalytic processes is a challenge for chemicals manufacture. Redox biotransformations are potentially attractive, but they rely on unstable and expensive nicotinamide coenzymes that have prevented their widespread exploitation. Stoichiometric use of natural coenzymes is not viable economically, and the instability of these molecules hinders catalytic processes that employ coenzyme recycling. Here, we investigate the efficiency of man-made synthetic biomimetics of the natural coenzymes NAD(P)H in redox biocatalysis. Extensive studies with a range of oxidoreductases belonging to the “ene” reductase family show that these biomimetics are excellent analogues of the natural coenzymes, revealed also in crystal structures of the ene reductase XenA with selected biomimetics. In selected cases, these biomimetics outperform the natural coenzymes. “Better-than-Nature” biomimetics should find widespread application in fine and specialty chemicals production by harnessing the power of high stereo-, regio-, and chemoselective redox biocatalysts and enabling reactions under mild conditions at low cost. PMID:26727612

Reverse Engineering Nature to Design Biomimetic Total Knee Implants.

PubMed

Varadarajan, Kartik Mangudi; Zumbrunn, Thomas; Rubash, Harry E; Malchau, Henrik; Muratoglu, Orhun K; Li, Guoan

2015-10-01

While contemporary total knee arthroplasty (TKA) provides tremendous clinical benefits, the normal feel and function of the knee is not fully restored. To address this, a novel design process was developed to reverse engineer "biomimetic" articular surfaces that are compatible with normal soft-tissue envelope and kinematics of the knee. The biomimetic articular surface is created by moving the TKA femoral component along in vivo kinematics of normal knees and carving out the tibial articular surface from a rectangular tibial block. Here, we describe the biomimetic design process. In addition, we utilize geometric comparisons and kinematic simulations to show that; (1) tibial articular surfaces of conventional implants are fundamentally incompatible with normal knee motion, and (2) the anatomic geometry of the biomimetic surface contributes directly to restoration of normal knee kinematics. Such biomimetic implants may enable us to achieve the long sought after goal of a "normal" knee post-TKA surgery. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Biomimetic superwettable materials with structural colours.

PubMed

Wang, Zelinlan; Guo, Zhiguang

2017-12-05

Structural colours and superwettability are of great interest due to their unique characteristics. However, the application of materials with either structural colours or superwettability is limited. Moreover, materials possessing both structural colours and superwettability are crucial for many practical applications. The combination of structural colours and superwettability can result in materials for use various applications, such as in sensors, detectors, bioassays, anti-counterfeiting, and liquid actuators, by controlling surfaces to repel or absorb liquids. Regarding superwettability and structural colours, surface texture and chemical composition are two factors for the construction of materials with superwettable structural colours. This review aims at offering a comprehensive elaboration of the mechanism, recent biomimetic research, and applications of biomimetic superwettable materials with structural colours. Furthermore, this review provides significant insight into the design, fabrication, and application of biomimetic superwettable materials with structural colours.

Biomimetic Structural Materials: Inspiration from Design and Assembly.

PubMed

Yaraghi, Nicholas A; Kisailus, David

2018-04-20

Nature assembles weak organic and inorganic constituents into sophisticated hierarchical structures, forming structural composites that demonstrate impressive combinations of strength and toughness. Two such composites are the nacre structure forming the inner layer of many mollusk shells, whose brick-and-mortar architecture has been the gold standard for biomimetic composites, and the cuticle forming the arthropod exoskeleton, whose helicoidal fiber-reinforced architecture has only recently attracted interest for structural biomimetics. In this review, we detail recent biomimetic efforts for the fabrication of strong and tough composite materials possessing the brick-and-mortar and helicoidal architectures. Techniques discussed for the fabrication of nacre- and cuticle-mimetic structures include freeze casting, layer-by-layer deposition, spray deposition, magnetically assisted slip casting, fiber-reinforced composite processing, additive manufacturing, and cholesteric self-assembly. Advantages and limitations to these processes are discussed, as well as the future outlook on the biomimetic landscape for structural composite materials.

Biomimetic Structural Materials: Inspiration from Design and Assembly

NASA Astrophysics Data System (ADS)

Yaraghi, Nicholas A.; Kisailus, David

2018-04-01

Nature assembles weak organic and inorganic constituents into sophisticated hierarchical structures, forming structural composites that demonstrate impressive combinations of strength and toughness. Two such composites are the nacre structure forming the inner layer of many mollusk shells, whose brick-and-mortar architecture has been the gold standard for biomimetic composites, and the cuticle forming the arthropod exoskeleton, whose helicoidal fiber-reinforced architecture has only recently attracted interest for structural biomimetics. In this review, we detail recent biomimetic efforts for the fabrication of strong and tough composite materials possessing the brick-and-mortar and helicoidal architectures. Techniques discussed for the fabrication of nacre- and cuticle-mimetic structures include freeze casting, layer-by-layer deposition, spray deposition, magnetically assisted slip casting, fiber-reinforced composite processing, additive manufacturing, and cholesteric self-assembly. Advantages and limitations to these processes are discussed, as well as the future outlook on the biomimetic landscape for structural composite materials.

Sustainability assessment of a lightweight biomimetic ceiling structure.

PubMed

Antony, Florian; Grießhammer, Rainer; Speck, Thomas; Speck, Olga

2014-03-01

An intensive and continuous debate centres on the question of whether biomimetics has a specific potential to contribute to sustainability. In the context of a case study, the objective of this paper is to contribute to this debate by presenting the first systematic approach to assess the sustainability of a complex biomimetic product. The object of inquiry is a lecture hall's ribbed slab. Based on criteria suggested by the Association of German Engineers (VDI), it has been verified that the slab has been correctly defined as biomimetic. Moreover, a systematic comparative product sustainability assessment has been carefully carried out. For purposes of comparison, estimated static calculations have been performed for conceivable current state-of-the-art lightweight ceiling structures. Alternative options are a hollow article slab and a pre-stressed flat slab. Besides a detailed benefit analysis and a discussion of social effects, their costs have also been compared. A particularly detailed life cycle assessment on the respective environmental impacts has also been performed. Results show that the biomimetic ribbed slab built in the 1960s is able to keep up with the current state-of-the-art lightweight solutions in terms of sustainability. These promising results encourage a systematic search for a broad range of sustainable biomimetic solutions.

Biological attachment devices: exploring nature's diversity for biomimetics.

PubMed

Gorb, Stanislav N

2008-05-13

Many species of animals and plants are supplied with diverse attachment devices, in which morphology depends on the species biology and the particular function in which the attachment device is involved. Many functional solutions have evolved independently in different lineages of animals and plants. Since the diversity of such biological structures is huge, there is a need for their classification. This paper, based on the original and literature data, proposes ordering of biological attachment systems according to several principles: (i) fundamental physical mechanism, according to which the system operates, (ii) biological function of the attachment device, and (iii) duration of the contact. Finally, we show a biomimetic potential of studies on biological attachment devices.

Biomimetic membranes and methods of making biomimetic membranes

DOEpatents

Rempe, Susan; Brinker, Jeffrey C.; Rogers, David Michael; Jiang, Ying-Bing; Yang, Shaorong

2016-11-08

The present disclosure is directed to biomimetic membranes and methods of manufacturing such membranes that include structural features that mimic the structures of cellular membrane channels and produce membrane designs capable of high selectivity and high permeability or adsorptivity. The membrane structure, material and chemistry can be selected to perform liquid separations, gas separation and capture, ion transport and adsorption for a variety of applications.

In vitro remineralization of hybrid layers using biomimetic analogs*

PubMed Central

Lin, Hui-ping; Lin, Jun; Li, Juan; Xu, Jing-hong; Mehl, Christian

2016-01-01

Resin-dentin bond degradation is a major cause of restoration failures. The major aim of the current study was to evaluate the impact of a remineralization medium on collagen matrices of hybrid layers of three different adhesive resins using nanotechnology methods. Coronal dentin surfaces were prepared from freshly extracted premolars and bonded to composite resin using three adhesive resins (FluoroBond II, Xeno-III-Bond, and iBond). From each tooth, two central slabs were selected for the study. The slabs used as controls were immersed in a simulated body fluid (SBF). The experimental slabs were immersed in a Portland cement-based remineralization medium that contained two biomimetic analogs (biomineralization medium (BRM)). Eight slabs per group were retrieved after 1, 2, 3, and 4 months, respectively and immersed in Rhodamine B for 24 h. Confocal laser scanning microscopy was used to evaluate the permeability of hybrid layers to Rhodamine B. Data were analyzed by analysis of variance (ANOVA) and Tukey’s honest significant difference (HSD) tests. After four months, all BRM specimens exhibited a significantly smaller fluorescent area than SBF specimens, indicating a remineralization of the hybrid layer (P≤0.05). A clinically applicable biomimetic remineralization delivery system could potentially slow down bond degradation. PMID:27819133

In vitro remineralization of hybrid layers using biomimetic analogs.

PubMed

Lin, Hui-Ping; Lin, Jun; Li, Juan; Xu, Jing-Hong; Mehl, Christian

Resin-dentin bond degradation is a major cause of restoration failures. The major aim of the current study was to evaluate the impact of a remineralization medium on collagen matrices of hybrid layers of three different adhesive resins using nanotechnology methods. Coronal dentin surfaces were prepared from freshly extracted premolars and bonded to composite resin using three adhesive resins (FluoroBond II, Xeno-III-Bond, and iBond). From each tooth, two central slabs were selected for the study. The slabs used as controls were immersed in a simulated body fluid (SBF). The experimental slabs were immersed in a Portland cement-based remineralization medium that contained two biomimetic analogs (biomineralization medium (BRM)). Eight slabs per group were retrieved after 1, 2, 3, and 4 months, respectively and immersed in Rhodamine B for 24 h. Confocal laser scanning microscopy was used to evaluate the permeability of hybrid layers to Rhodamine B. Data were analyzed by analysis of variance (ANOVA) and Tukey's honest significant difference (HSD) tests. After four months, all BRM specimens exhibited a significantly smaller fluorescent area than SBF specimens, indicating a remineralization of the hybrid layer (P≤0.05). A clinically applicable biomimetic remineralization delivery system could potentially slow down bond degradation.

Amelogenin and Enamel Biomimetics.

PubMed

Ruan, Qichao; Moradian-Oldak, Janet

Mature tooth enamel is acellular and does not regenerate itself. Developing technologies that rebuild tooth enamel and preserve tooth structure is therefore of great interest. Considering the importance of amelogenin protein in dental enamel formation, its ability to control apatite mineralization in vitro , and its potential to be applied in fabrication of future bio-inspired dental material this review focuses on two major subjects: amelogenin and enamel biomimetics. We review the most recent findings on amelogenin secondary and tertiary structural properties with a focus on its interactions with different targets including other enamel proteins, apatite mineral, and phospholipids. Following a brief overview of enamel hierarchical structure and its mechanical properties we will present the state-of-the-art strategies in the biomimetic reconstruction of human enamel.

Biomimetic Delivery with Micro- and Nanoparticles

PubMed Central

Balmert, Stephen C.; Little, Steven R.

2013-01-01

The nascent field of biomimetic delivery with micro- and nanoparticles (MNP) has advanced considerably in recent years. Drawing inspiration from the ways that cells communicate in the body, several different modes of “delivery” (i.e. temporospatial presentation of biological signals) have been investigated in a number of therapeutic contexts. In particular, this review focuses on (1) controlled release formulations that deliver natural soluble factors with physiologically relevant temporal context, (2) presentation of surface-bound ligands to cells, with spatial organization of ligands ranging from isotropic to dynamically anisotropic, and (3) physical properties of particles, including size, shape and mechanical stiffness, which mimic those of natural cells. Importantly, the context provided by multimodal, or multifactor delivery represents a key element of most biomimetic MNP systems, a concept illustrated by an analogy to human interpersonal communication. Regulatory implications of increasingly sophisticated and “cell-like” biomimetic MNP systems are also discussed. PMID:22528985

BatSLAM: Simultaneous localization and mapping using biomimetic sonar.

PubMed

Steckel, Jan; Peremans, Herbert

2013-01-01

We propose to combine a biomimetic navigation model which solves a simultaneous localization and mapping task with a biomimetic sonar mounted on a mobile robot to address two related questions. First, can robotic sonar sensing lead to intelligent interactions with complex environments? Second, can we model sonar based spatial orientation and the construction of spatial maps by bats? To address these questions we adapt the mapping module of RatSLAM, a previously published navigation system based on computational models of the rodent hippocampus. We analyze the performance of the proposed robotic implementation operating in the real world. We conclude that the biomimetic navigation model operating on the information from the biomimetic sonar allows an autonomous agent to map unmodified (office) environments efficiently and consistently. Furthermore, these results also show that successful navigation does not require the readings of the biomimetic sonar to be interpreted in terms of individual objects/landmarks in the environment. We argue that the system has applications in robotics as well as in the field of biology as a simple, first order, model for sonar based spatial orientation and map building.

BatSLAM: Simultaneous Localization and Mapping Using Biomimetic Sonar

PubMed Central

Steckel, Jan; Peremans, Herbert

2013-01-01

We propose to combine a biomimetic navigation model which solves a simultaneous localization and mapping task with a biomimetic sonar mounted on a mobile robot to address two related questions. First, can robotic sonar sensing lead to intelligent interactions with complex environments? Second, can we model sonar based spatial orientation and the construction of spatial maps by bats? To address these questions we adapt the mapping module of RatSLAM, a previously published navigation system based on computational models of the rodent hippocampus. We analyze the performance of the proposed robotic implementation operating in the real world. We conclude that the biomimetic navigation model operating on the information from the biomimetic sonar allows an autonomous agent to map unmodified (office) environments efficiently and consistently. Furthermore, these results also show that successful navigation does not require the readings of the biomimetic sonar to be interpreted in terms of individual objects/landmarks in the environment. We argue that the system has applications in robotics as well as in the field of biology as a simple, first order, model for sonar based spatial orientation and map building. PMID:23365647

Development of biomimetic quadruped walking robot with 2-DOF waist joint

NASA Astrophysics Data System (ADS)

Kim, Kyoung-Ho; Park, Se-Hoon; Lee, Yun-Jung

2005-12-01

This paper presented a novel bio-mimetic quadruped walking robot with 2-DOF (Degree Of Freedom) waist joint, which connects the front and the rear parts of the body. The waist-jointed walking robot can guarantee more stable and more animal-like gait than that of a conventional single-rigid-body walking robot. The developed robot, called ELIRO-II (Eating LIzard RObot version 2), can bend its body from side to side by using 1-DOF passive waist joint while the legs is transferred, thereby increasing the stride and speed of the robot. In addition, ELIRO-II has one more active DOF to bend its body up and down, which increases the mobility in irregular terrain such as slope and stairs. We design the mechanical structure of the robot, which is small and light to have high mobility. This research described characteristics of the 2-DOF waists joint and leg mechanism as well as a hardware and software of the controller of ELIRO-II.

Amelogenin and Enamel Biomimetics

PubMed Central

Ruan, Qichao; Moradian-Oldak, Janet

2015-01-01

Mature tooth enamel is acellular and does not regenerate itself. Developing technologies that rebuild tooth enamel and preserve tooth structure is therefore of great interest. Considering the importance of amelogenin protein in dental enamel formation, its ability to control apatite mineralization in vitro, and its potential to be applied in fabrication of future bio-inspired dental material this review focuses on two major subjects: amelogenin and enamel biomimetics. We review the most recent findings on amelogenin secondary and tertiary structural properties with a focus on its interactions with different targets including other enamel proteins, apatite mineral, and phospholipids. Following a brief overview of enamel hierarchical structure and its mechanical properties we will present the state-of-the-art strategies in the biomimetic reconstruction of human enamel. PMID:26251723

On the Biomimetic Design of Agile-Robot Legs

PubMed Central

Garcia, Elena; Arevalo, Juan Carlos; Muñoz, Gustavo; Gonzalez-de-Santos, Pablo

2011-01-01

The development of functional legged robots has encountered its limits in human-made actuation technology. This paper describes research on the biomimetic design of legs for agile quadrupeds. A biomimetic leg concept that extracts key principles from horse legs which are responsible for the agile and powerful locomotion of these animals is presented. The proposed biomimetic leg model defines the effective leg length, leg kinematics, limb mass distribution, actuator power, and elastic energy recovery as determinants of agile locomotion, and values for these five key elements are given. The transfer of the extracted principles to technological instantiations is analyzed in detail, considering the availability of current materials, structures and actuators. A real leg prototype has been developed following the biomimetic leg concept proposed. The actuation system is based on the hybrid use of series elasticity and magneto-rheological dampers which provides variable compliance for natural motion. From the experimental evaluation of this prototype, conclusions on the current technological barriers to achieve real functional legged robots to walk dynamically in agile locomotion are presented. PMID:22247667

On the biomimetic design of agile-robot legs.

PubMed

Garcia, Elena; Arevalo, Juan Carlos; Muñoz, Gustavo; Gonzalez-de-Santos, Pablo

2011-01-01

The development of functional legged robots has encountered its limits in human-made actuation technology. This paper describes research on the biomimetic design of legs for agile quadrupeds. A biomimetic leg concept that extracts key principles from horse legs which are responsible for the agile and powerful locomotion of these animals is presented. The proposed biomimetic leg model defines the effective leg length, leg kinematics, limb mass distribution, actuator power, and elastic energy recovery as determinants of agile locomotion, and values for these five key elements are given. The transfer of the extracted principles to technological instantiations is analyzed in detail, considering the availability of current materials, structures and actuators. A real leg prototype has been developed following the biomimetic leg concept proposed. The actuation system is based on the hybrid use of series elasticity and magneto-rheological dampers which provides variable compliance for natural motion. From the experimental evaluation of this prototype, conclusions on the current technological barriers to achieve real functional legged robots to walk dynamically in agile locomotion are presented.

Biomimetic and bioinspired nanoparticles for targeted drug delivery.

PubMed

Gagliardi, Mariacristina

2017-03-01

In drug targeting, the urgent need for more effective and less iatrogenic therapies is pushing toward a complete revision of carrier setup. After the era of 'articles used as homing systems', novel prototypes are now emerging. Newly conceived carriers are endowed with better biocompatibility, biodistribution and targeting properties. The biomimetic approach bestows such improved functional properties. Exploiting biological molecules, organisms and cells, or taking inspiration from them, drug vector performances are now rapidly progressing toward the perfect carrier. Following this direction, researchers have refined carrier properties, achieving significant results. The present review summarizes recent advances in biomimetic and bioinspired drug vectors, derived from biologicals or obtained by processing synthetic materials with a biomimetic approach.

Copper-containing monooxygenases: enzymatic and biomimetic studies of the O-atom transfer catalysis.

PubMed

Blain, Ingrid; Slama, Patrick; Giorgi, Michel; Tron, Thierry; Réglier, Marius

2002-04-01

This review reports our recent studies or the mechanism of O-atom transfer to a benzylic C-H bond promoted by Dopamine beta-Hydroxylase (DBH) and its biomimetic models. We demonstrate that it is possible to carry out parallel and comparative studies on this enzyme (DBH) and its biomimetic models with the same substrate: 2-aminoindane (3). It was chosen because its two stereogenic centers, both in benzylic positions, make it very powerful for studying the stereochemistry of an O-atom transfer reaction. DBH-catalyzed hydroxylation of 3 produced exclusively 14% of trans-(1S,2S)-2-amino-1-indanol (4) (93% ee). Studies with stereospecifically deuterium-labeled 2-aminoindanes (1R,2S)-3b and (1S,2S)-3a showed that the formation of 4 was the rcsult of an overall process with retention of configuration where an O-atom is stereospecifically inserted in the trans pro-S position of the substrate. With copper(I) and (II) complexes of IndPY2 ligands we studied the reaction with dioxygen and observed an O-atom transfer to a benzylic C-H bond which was performed in the same manner as that of DBH. With the deuterium-labeled cis-2-d-IndPY2 ligand, we demonstrated that the reaction occurs by a stereospecific process with retention of configuration. In both cases (enzymatic vs. biomimetic) the O-atom transfers occur in a two-step process involving radical intermediates.

Conventional vs Biomimetic Approaches to the Exploration of Mars

NASA Astrophysics Data System (ADS)

Ellery, A.

It is not usual to refer to convention in planetary exploration missions by virtue of the innovation required for such projects. The term conventional refers to the methodologies, tools and approaches typically adopted in engineering that are applied to such missions. Presented is a "conventional" Mars rover mission in which the author was involved - ExoMars - into which is interspersed references to examples where biomimetic approaches may yield superior capabilities. Biomimetics is a relatively recently active area of research which seeks to examine how biological systems solve the problem of survival in the natural environment. Biological organisms are autonomous entities that must survive in a hostile world adapting both adaptivity and robustness. It is not then surprising that biomimetics is particularly useful when applied to robotic elements of a Mars exploration mission. I present a number of areas in which biomimetics may yield new solutions to the problem of Mars exploration - optic flow navigation, potential field navigation, genetically-evolved neuro-controllers, legged locomotion, electric motors implementing muscular behaviour, and a biomimetic drill based on the wood wasp ovipositor. Each of these techniques offers an alternative approach to conventional ones. However, the perceptive hurdles are likely to dwarf the technical hurdles in implementing many of these methods in the near future.

Biomimetic chemical sensors using bioengineered olfactory and taste cells.

PubMed

Du, Liping; Zou, Ling; Zhao, Luhang; Wang, Ping; Wu, Chunsheng

2014-01-01

Biological olfactory and taste systems are natural chemical sensing systems with unique performances for the detection of environmental chemical signals. With the advances in olfactory and taste transduction mechanisms, biomimetic chemical sensors have achieved significant progress due to their promising prospects and potential applications. Biomimetic chemical sensors exploit the unique capability of biological functional components for chemical sensing, which are often sourced from sensing units of biological olfactory or taste systems at the tissue level, cellular level, or molecular level. Specifically, at the cellular level, there are mainly two categories of cells have been employed for the development of biomimetic chemical sensors, which are natural cells and bioengineered cells, respectively. Natural cells are directly isolated from biological olfactory and taste systems, which are convenient to achieve. However, natural cells often suffer from the undefined sensing properties and limited amount of identical cells. On the other hand, bioengineered cells have shown decisive advantages to be applied in the development of biomimetic chemical sensors due to the powerful biotechnology for the reconstruction of the cell sensing properties. Here, we briefly summarized the most recent advances of biomimetic chemical sensors using bioengineered olfactory and taste cells. The development challenges and future trends are discussed as well.

State-of-the-art and outlook for biomimetic materials

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

Richman, R.H.; Bond, G.M.; McNaughton, W.P.

1994-11-01

A remarkable diversity of structures and molecular functions has evolved in plants and animals. Many of these natural substances have properties or capabilities that belie their origins in humble, everyday, starting materials. Consequently, there is a growing awareness among scientists and engineers that biological systems can be a valuable source of inspiration for man-made materials. Emphasis in this assessment is on biomimetics; that is, the achievement of unusual materials properties or processes by mimicking novel aspects of biological systems. Five broad areas are selected for detailed investigation: Mimicking of Natural Material Designs; Biomimetic Materials Processing; Artificial Photosynthesis; Biomimetic Molecular Electronics;more » and Biomimetic Catalysis. Each of these topics is examined in terms of current activities and approaches, key aspects, unresolved issues, and implications for the power industry. Finally, the researchers, their organizations, the main thrusts of investigation, achievements, and funding agencies are summarized in tabular form.« less

Biomimetics and the case of the remarkable ragworms.

PubMed

Hesselberg, Thomas

2007-08-01

Biomimetics is a rapidly growing field both as an academic and as an applied discipline. This paper gives a short introduction to the current status of the discipline before it describes three approaches to biomimetics: the mechanism-driven, which is based on the study of a specific mechanism; the focused organism-driven, which is based on the study of one function in a model organism; and the integrative organism-driven approach, where multiple functions of a model organism provide inspiration. The first two are established approaches and include many modern studies and the famous biomimetic discoveries of Velcro and the Lotus-Effect, whereas the last approach is not yet well recognized. The advantages of the integrative organism-driven approach are discussed using the ragworms as a case study. A morphological and locomotory study of these marine polychaetes reveals their biomimetic potential, which includes using their ability to move in slippery substrates as inspiration for novel endoscopes, using their compound setae as models for passive friction structures and using their three gaits, slow crawling, fast crawling, and swimming as well as their rapid burrowing technique to provide inspiration for the design of displacement pumps and multifunctional robots.

Biomimetics and the case of the remarkable ragworms

NASA Astrophysics Data System (ADS)

Hesselberg, Thomas

2007-08-01

Biomimetics is a rapidly growing field both as an academic and as an applied discipline. This paper gives a short introduction to the current status of the discipline before it describes three approaches to biomimetics: the mechanism-driven, which is based on the study of a specific mechanism; the focused organism-driven, which is based on the study of one function in a model organism; and the integrative organism-driven approach, where multiple functions of a model organism provide inspiration. The first two are established approaches and include many modern studies and the famous biomimetic discoveries of Velcro and the Lotus-Effect, whereas the last approach is not yet well recognized. The advantages of the integrative organism-driven approach are discussed using the ragworms as a case study. A morphological and locomotory study of these marine polychaetes reveals their biomimetic potential, which includes using their ability to move in slippery substrates as inspiration for novel endoscopes, using their compound setae as models for passive friction structures and using their three gaits, slow crawling, fast crawling, and swimming as well as their rapid burrowing technique to provide inspiration for the design of displacement pumps and multifunctional robots.

Biomimetic coatings for bone tissue engineering of critical-sized defects.

PubMed

Liu, Yuelian; Wu, Gang; de Groot, Klaas

2010-10-06

The repair of critical-sized bone defects is still challenging in the fields of implantology, maxillofacial surgery and orthopaedics. Current therapies such as autografts and allografts are associated with various limitations. Cytokine-based bone tissue engineering has been attracting increasing attention. Bone-inducing agents have been locally injected to stimulate the native bone-formation activity, but without much success. The reason is that these drugs must be delivered slowly and at a low concentration to be effective. This then mimics the natural method of cytokine release. For this purpose, a suitable vehicle was developed, the so-called biomimetic coating, which can be deposited on metal implants as well as on biomaterials. Materials that are currently used to fill bony defects cannot by themselves trigger bone formation. Therefore, biological functionalization of such materials by the biomimetic method resulted in a novel biomimetic coating onto different biomaterials. Bone morphogenetic protein 2 (BMP-2)-incorporated biomimetic coating can be a solution for a large bone defect repair in the fields of dental implantology, maxillofacial surgery and orthopaedics. Here, we review the performance of the biomimetic coating both in vitro and in vivo.

Bio-Mimetic Sensors Based on Molecularly Imprinted Membranes

PubMed Central

Algieri, Catia; Drioli, Enrico; Guzzo, Laura; Donato, Laura

2014-01-01

An important challenge for scientific research is the production of artificial systems able to mimic the recognition mechanisms occurring at the molecular level in living systems. A valid contribution in this direction resulted from the development of molecular imprinting. By means of this technology, selective molecular recognition sites are introduced in a polymer, thus conferring it bio-mimetic properties. The potential applications of these systems include affinity separations, medical diagnostics, drug delivery, catalysis, etc. Recently, bio-sensing systems using molecularly imprinted membranes, a special form of imprinted polymers, have received the attention of scientists in various fields. In these systems imprinted membranes are used as bio-mimetic recognition elements which are integrated with a transducer component. The direct and rapid determination of an interaction between the recognition element and the target analyte (template) was an encouraging factor for the development of such systems as alternatives to traditional bio-assay methods. Due to their high stability, sensitivity and specificity, bio-mimetic sensors-based membranes are used for environmental, food, and clinical uses. This review deals with the development of molecularly imprinted polymers and their different preparation methods. Referring to the last decades, the application of these membranes as bio-mimetic sensor devices will be also reported. PMID:25196110

Biomimetics of human movement: functional or aesthetic?

PubMed

Harris, Christopher M

2009-09-01

How should robotic or prosthetic arms be programmed to move? Copying human smooth movements is popular in synthetic systems, but what does this really achieve? We cannot address these biomimetic issues without a deep understanding of why natural movements are so stereotyped. In this article, we distinguish between 'functional' and 'aesthetic' biomimetics. Functional biomimetics requires insight into the problem that nature has solved and recognition that a similar problem exists in the synthetic system. In aesthetic biomimetics, nature is copied for its own sake and no insight is needed. We examine the popular minimum jerk (MJ) model that has often been used to generate smooth human-like point-to-point movements in synthetic arms. The MJ model was originally justified as maximizing 'smoothness'; however, it is also the limiting optimal trajectory for a wide range of cost functions for brief movements, including the minimum variance (MV) model, where smoothness is a by-product of optimizing the speed-accuracy trade-off imposed by proportional noise (PN: signal-dependent noise with the standard deviation proportional to mean). PN is unlikely to be dominant in synthetic systems, and the control objectives of natural movements (speed and accuracy) would not be optimized in synthetic systems by human-like movements. Thus, employing MJ or MV controllers in robotic arms is just aesthetic biomimetics. For prosthetic arms, the goal is aesthetic by definition, but it is still crucial to recognize that MV trajectories and PN are deeply embedded in the human motor system. Thus, PN arises at the neural level, as a recruitment strategy of motor units and probably optimizes motor neuron noise. Human reaching is under continuous adaptive control. For prosthetic devices that do not have this natural architecture, natural plasticity would drive the system towards unnatural movements. We propose that a truly neuromorphic system with parallel force generators (muscle fibres) and noisy

Biomimetics in Tribology

NASA Astrophysics Data System (ADS)

Gebeshuber, I. C.; Majlis, B. Y.; Stachelberger, H.

Science currently goes through a major change. Biology is evolving as new Leitwissenschaft, with more and more causation and natural laws being uncovered. The term `technoscience' denotes the field where science and technology are inseparably interconnected, the trend goes from papers to patents, and the scientific `search for truth' is increasingly replaced by search for applications with a potential economic value. Biomimetics, i.e. knowledge transfer from biology to technology, is a field that has the potential to drive major technical advances. The biomimetic approach might change the research landscape and the engineering culture dramatically, by the blending of disciplines. It might substantially support successful mastering of current tribological challenges: friction, adhesion, lubrication and wear in devices and systems from the meter to the nanometer scale. A highly successful method in biomimectics, the biomimicry innovation method, is applied in this chapter to identify nature's best practices regarding two key issues in tribology: maintenance of the physical integrity of a system, and permanent as well as temporary attachment. The best practices identified comprise highly diverse organisms and processes and are presented in a number of tables with detailed references.

A biomimetic projector with high subwavelength directivity based on dolphin biosonar

NASA Astrophysics Data System (ADS)

Zhang, Yu; Gao, Xiaowei; Zhang, Sai; Cao, Wenwu; Tang, Liguo; Wang, Ding; Li, Yan

2014-09-01

Based on computed tomography of a Yangtze finless porpoise's biosonar system, a biomimetic structure was designed to include air cavity, gradient-index material, and steel outer-structure mimicking air sacs, melon, and skull, respectively. The mainlobe pressure was about three times higher, the angular resolution was one order of magnitude higher, and the effective source size was orders of magnitude larger than those of the subwavelength source without the biomimetic structure. The superior subwavelength directivity over a broad bandwidth suggests potential applications of this biomimetic projector in underwater sonar, medical ultrasonography, and other related applications.

A future of living machines?: International trends and prospects in biomimetic and biohybrid systems

NASA Astrophysics Data System (ADS)

Prescott, Tony J.; Lepora, Nathan; Vershure, Paul F. M. J.

2014-03-01

Research in the fields of biomimetic and biohybrid systems is developing at an accelerating rate. Biomimetics can be understood as the development of new technologies using principles abstracted from the study of biological systems, however, biomimetics can also be viewed from an alternate perspective as an important methodology for improving our understanding of the world we live in and of ourselves as biological organisms. A biohybrid entity comprises at least one artificial (engineered) component combined with a biological one. With technologies such as microscale mobile computing, prosthetics and implants, humankind is moving towards a more biohybrid future in which biomimetics helps us to engineer biocompatible technologies. This paper reviews recent progress in the development of biomimetic and biohybrid systems focusing particularly on technologies that emulate living organisms—living machines. Based on our recent bibliographic analysis [1] we examine how biomimetics is already creating life-like robots and identify some key unresolved challenges that constitute bottlenecks for the field. Drawing on our recent research in biomimetic mammalian robots, including humanoids, we review the future prospects for such machines and consider some of their likely impacts on society, including the existential risk of creating artifacts with significant autonomy that could come to match or exceed humankind in intelligence. We conclude that living machines are more likely to be a benefit than a threat but that we should also ensure that progress in biomimetics and biohybrid systems is made with broad societal consent.

Towards a theoretical clarification of biomimetics using conceptual tools from engineering design.

PubMed

Drack, M; Limpinsel, M; de Bruyn, G; Nebelsick, J H; Betz, O

2017-12-13

Many successful examples of biomimetic products are available, and most research efforts in this emerging field are directed towards the development of specific applications. The theoretical and conceptual underpinnings of the knowledge transfer between biologists, engineers and architects are, however, poorly investigated. The present article addresses this gap. We use a 'technomorphic' approach, i.e. the application of conceptual tools derived from engineering design, to better understand the processes operating during a typical biomimetic research project. This helps to elucidate the formal connections between functions, working principles and constructions (in a broad sense)-because the 'form-function-relationship' is a recurring issue in biology and engineering. The presented schema also serves as a conceptual framework that can be implemented for future biomimetic projects. The concepts of 'function' and 'working principle' are identified as the core elements in the biomimetic knowledge transfer towards applications. This schema not only facilitates the development of a common language in the emerging science of biomimetics, but also promotes the interdisciplinary dialogue among its subdisciplines.

Biomimetic mineral self-organization from silica-rich spring waters.

PubMed

García-Ruiz, Juan Manuel; Nakouzi, Elias; Kotopoulou, Electra; Tamborrino, Leonardo; Steinbock, Oliver

2017-03-01

Purely inorganic reactions of silica, metal carbonates, and metal hydroxides can produce self-organized complex structures that mimic the texture of biominerals, the morphology of primitive organisms, and that catalyze prebiotic reactions. To date, these fascinating structures have only been synthesized using model solutions. We report that mineral self-assembly can be also obtained from natural alkaline silica-rich water deriving from serpentinization. Specifically, we demonstrate three main types of mineral self-assembly: (i) nanocrystalline biomorphs of barium carbonate and silica, (ii) mesocrystals and crystal aggregates of calcium carbonate with complex biomimetic textures, and (iii) osmosis-driven metal silicate hydrate membranes that form compartmentalized, hollow structures. Our results suggest that silica-induced mineral self-assembly could have been a common phenomenon in alkaline environments of early Earth and Earth-like planets.

The binuclear nickel center in the A-cluster of acetyl-CoA synthase (ACS) and two biomimetic dinickel complexes studied by X-ray absorption and emission spectroscopy

NASA Astrophysics Data System (ADS)

Schrapers, P.; Mebs, S.; Ilina, Y.; Warner, D. S.; Wörmann, C.; Schuth, N.; Kositzki, R.; Dau, H.; Limberg, C.; Dobbek, H.; Haumann, M.

2016-05-01

Acetyl-CoA synthase (ACS) is involved in the bacterial carbon oxide conversion pathway. The binuclear nickel sites in ACS enzyme and two biomimetic synthetic compounds containing a Ni(II)Ni(II) unit (1 and 2) were compared using XAS/XES. EXAFS analysis of ACS proteins revealed similar Ni-N/O/S bond lengths and Ni-Ni/Fe distances as in the crystal structure in oxidized ACS, but elongated Ni-ligand bonds in reduced ACS, suggesting more reduced nickel species. The XANES spectra of ACS and the dinickel complexes showed overall similar shapes, but less resolved pre-edge and edge features in ACS, attributed to more distorted square-planar nickel sites in particular in reduced ACS. DFT calculation of pre-edge absorption and Kβ2,5 emission features reproduced the experimental spectra of the synthetic complexes, was sensitive even to the small geometry differences in 1 and 2, and indicated low-spin Ni(II) sites. Comparison of nickel sites in proteins and biomimetic compounds is valuable for deducing structural and electronic differences in response to ligation and redox changes.

Preparation, anti-biofouling and drag-reduction properties of a biomimetic shark skin surface

PubMed Central

Pu, Xia; Li, Guangji; Huang, Hanlu

2016-01-01

ABSTRACT Shark skin surfaces show non-smoothness characteristics due to the presence of a riblet structure. In this study, biomimetic shark skin was prepared by using the polydimethylsiloxane (PDMS)-embedded elastomeric stamping (PEES) method. Scanning electron microscopy (SEM) was used to examine the surface microstructure and fine structure of shark skin and biomimetic shark skin. To analyse the hydrophobic mechanism of the shark skin surface microstructure, the effect of biomimetic shark skin surface microstructure on surface wettability was evaluated by recording water contact angle. Additionally, protein adhesion experiments and anti-algae adhesion performance testing experiments were used to investigate and evaluate the anti-biofouling properties of the surface microstructure of biomimetic shark skin. The recorded values of the water contact angle of differently microstructured surfaces revealed that specific microstructures have certain effects on surface wettability. The anti-biofouling properties of the biomimetic shark skin surface with microstructures were superior to a smooth surface using the same polymers as substrates. Moreover, the air layer fixed on the surface of the biomimetic shark skin was found to play a key role in their antibiont adhesion property. An experiment into drag reduction was also conducted. Based on the experimental results, the microstructured surface of the prepared biomimetic shark skin played a significant role in reducing drag. The maximum of drag reduction rate is 12.5%, which is higher than the corresponding maximum drag reduction rate of membrane material with a smooth surface. PMID:26941105

Preparation, anti-biofouling and drag-reduction properties of a biomimetic shark skin surface.

PubMed

Pu, Xia; Li, Guangji; Huang, Hanlu

2016-04-15

Shark skin surfaces show non-smoothness characteristics due to the presence of a riblet structure. In this study, biomimetic shark skin was prepared by using the polydimethylsiloxane (PDMS)-embedded elastomeric stamping (PEES) method. Scanning electron microscopy (SEM) was used to examine the surface microstructure and fine structure of shark skin and biomimetic shark skin. To analyse the hydrophobic mechanism of the shark skin surface microstructure, the effect of biomimetic shark skin surface microstructure on surface wettability was evaluated by recording water contact angle. Additionally, protein adhesion experiments and anti-algae adhesion performance testing experiments were used to investigate and evaluate the anti-biofouling properties of the surface microstructure of biomimetic shark skin. The recorded values of the water contact angle of differently microstructured surfaces revealed that specific microstructures have certain effects on surface wettability. The anti-biofouling properties of the biomimetic shark skin surface with microstructures were superior to a smooth surface using the same polymers as substrates. Moreover, the air layer fixed on the surface of the biomimetic shark skin was found to play a key role in their antibiont adhesion property. An experiment into drag reduction was also conducted. Based on the experimental results, the microstructured surface of the prepared biomimetic shark skin played a significant role in reducing drag. The maximum of drag reduction rate is 12.5%, which is higher than the corresponding maximum drag reduction rate of membrane material with a smooth surface. © 2016. Published by The Company of Biologists Ltd.

Assessment of sedimentary Cu availability: A comparison of biomimetic and AVS approaches

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

Chen, Z.; Mayer, L.M.

1999-02-15

Sedimentary Cu bioavailability during deposit feeding is determined by both the digestive physiology of the organisms and the geochemistry of the sediments. The authors assessed the contribution of these two factors by using a biomimetic approach involving extraction of Cu with digestive fluids of two deposit feeders and one suspension feeder and a geochemical approach measuring Cu associated with acid-volatile sulfide (AVS) in sediments. Cu bioavailability determined by the biomimetic method varied among species with varying digestive physiology but all showed a marked increase when SEM{sub Cu}-AVS {ge} 0, corroborating the premise underlying the AVS method in determining sedimentary Cumore » bioavailability. The existence of a positive SEM{sub Cu}-AVS threshold suggests the existence of additional Cu-binding phases or mixed Cu(I)--Cu(II) sulfides in sediments. In addition, Cu bioavailable to digestive fluids was much less than that measured as SEM{sub Cu}-AVS, indicating that the AVS method overestimates Cu bioavailability to digestive fluid of deposit feeders. Incubation of digestive fluids with two Cu-bound model phases, goethite and sulfide, corroborated the relative unavailability of sulfide-bound Cu. Subsurface deposit feeders feeding on anoxic sediments may be exposed to less Cu than their surface-feeding counterparts in Cu-contaminated environments.« less

Emerging Biomimetic Applications of DNA Nanotechnology.

PubMed

Shen, Haijing; Wang, Yingqian; Wang, Jie; Li, Zhihao; Yuan, Quan

2018-06-25

Re-engineering cellular components and biological processes has received great interest and promised compelling advantages in applications ranging from basic cell biology to biomedicine. With the advent of DNA nanotechnology, the programmable self-assembly ability makes DNA an appealing candidate for rational design of artificial components with different structures and functions. This Forum Article summarizes recent developments of DNA nanotechnology in mimicking the structures and functions of existing cellular components. We highlight key successes in the achievements of DNA-based biomimetic membrane proteins and discuss the assembly behavior of these artificial proteins. Then, we focus on the construction of higher-order structures by DNA nanotechnology to recreate cell-like structures. Finally, we explore the current challenges and speculate on future directions of DNA nanotechnology in biomimetics.

Designing Biomimetic Materials from Marine Organisms.

PubMed

Nichols, William T

2015-01-01

Two biomimetic design approaches that apply biological solutions to engineering problems are discussed. In the first case, motivation comes from an engineering problem and the key challenge is to find analogous biological functions and map them into engineering materials. We illustrate with an example of water pollution remediation through appropriate design of a biomimetic sponge. In the second case, a biological function is already known and the challenge is to identify the appropriate engineering problem. We demonstrate the biological approach with marine diatoms that control energy and materials at their surface providing inspiration for a number of engineering applications. In both cases, it is essential to select materials and structures at the nanoscale to control energy and materials flows at interfaces.

Biomimetic patterned surfaces for controllable friction in micro- and nanoscale devices

NASA Astrophysics Data System (ADS)

Singh, Arvind; Suh, Kahp-Yang

2013-12-01

Biomimetics is the study and simulation of biological systems for desired functional properties. It involves the transformation of underlying principles discovered in nature into man-made technologies. In this context, natural surfaces have significantly inspired and motivated new solutions for micro- and nano-scale devices (e.g., Micro/Nano-Electro-Mechanical Systems, MEMS/NEMS) towards controllable friction, during their operation. As a generic solution to reduce friction at small scale, various thin films/coatings have been employed in the last few decades. In recent years, inspiration from `Lotus Effect' has initiated a new research direction for controllable friction with biomimetic patterned surfaces. By exploiting the intrinsic hydrophobicity and ability to reduce contact area, such micro- or nano-patterned surfaces have demonstrated great strength and potential for applications in MEMS/NEMS devices. This review highlights recent advancements on the design, development and performance of these biomimetic patterned surfaces. Also, we present some hybrid approaches to tackle current challenges in biomimetic tribological applications for MEMS/NEMS devices.

Biofouling and Design of a Biomimetic Hull-Grooming Tool

DTIC Science & Technology

2007-09-14

have barred the use of organotin compounds such as tributyltin ( TBT ) and copper-based paints, which are currently used by the Navy and have become...copper into the water, killing the fouling organisms. There is new research in biomimetic polymers that deter fouling, but are non- toxic . These polymers...is new research in biomimetic polymers that deter fouling, but are non- toxic . These polymers are rigidly attached to the hull surface extending

Biomimetic Hydrogel Materials

DOEpatents

Bertozzi, Carolyn , Mukkamala, Ravindranath , Chen, Oing , Hu, Hopin , Baude, Dominique

2003-04-22

Novel biomimetic hydrogel materials and methods for their preparation. Hydrogels containing acrylamide-functionalized carbohydrate, sulfoxide, sulfide or sulfone copolymerized with a hydrophilic or hydrophobic copolymerizing material selected from the group consisting of an acrylamide, methacrylamide, acrylate, methacrylate, vinyl and a derivative thereof present in concentration from about 1 to about 99 wt %. and methods for their preparation. The method of use of the new hydrogels for fabrication of soft contact lenses and biomedical implants.

Biomimetic hydrogel materials

DOEpatents

Bertozzi, Carolyn; Mukkamala, Ravindranath; Chen, Qing; Hu, Hopin; Baude, Dominique

2000-01-01

Novel biomimetic hydrogel materials and methods for their preparation. Hydrogels containing acrylamide-functionalized carbohydrate, sulfoxide, sulfide or sulfone copolymerized with a hydrophilic or hydrophobic copolymerizing material selected from the group consisting of an acrylamide, methacrylamide, acrylate, methacrylate, vinyl and a derivative thereof present in concentration from about 1 to about 99 wt %. and methods for their preparation. The method of use of the new hydrogels for fabrication of soft contact lenses and biomedical implants.

Phospholipid-sepiolite biomimetic interfaces for the immobilization of enzymes.

PubMed

Wicklein, Bernd; Darder, Margarita; Aranda, Pilar; Ruiz-Hitzky, Eduardo

2011-11-01

Biomimetic interfaces based on phosphatidylcholine (PC) assembled to the natural silicate sepiolite were prepared for the stable immobilization of the urease and cholesterol oxidase enzymes. This is an important issue in practical advanced applications such as biocatalysis or biosensing. The supported lipid bilayer (BL-PC), prepared from PC adsorption, was used for immobilization of enzymes and the resulting biomimetic systems were compared to several other supported layers including a lipid monolayer (ML-PC), a mixed phosphatidylcholine/octyl-galactoside layer (PC-OGal), a cetyltrimethylammonium monolayer (CTA), and also to the bare sepiolite surface. Interfacial characteristics of these layers were investigated with a focus on layer packing density, hydrophilicity/hydrophobicity, and surface charge, which are being considered as key points for enzyme immobilization and stabilization of their biological activity. Cytoplasmic urease and membrane-bound cholesterol oxidase, which served as model enzymes, were immobilized on the different PC-based hybrid materials to probe their biomimetic character. Enzymatic activity was assessed by cyclic voltammetry and UV-vis spectrophotometry. The resulting enzyme/bio-organoclay hybrids were applied as active phase of a voltammetric urea biosensor and cholesterol bioreactor, respectively. Urease supported on sepiolite/BL-PC proved to maintain its enzymatic activity over several months while immobilized cholesterol oxidase demonstrated high reusability as biocatalyst. The results emphasize the good preservation of bioactivity due to the accommodation of the enzymatic system within the biomimetic lipid interface on sepiolite.

A review of underwater bio-mimetic propulsion: cruise and fast-start

NASA Astrophysics Data System (ADS)

Chao, Li-Ming; Cao, Yong-Hui; Pan, Guang

2017-08-01

This paper reviews recent developments in the understanding of underwater bio-mimetic propulsion. Two impressive models of underwater propulsion are considered: cruise and fast-start. First, we introduce the progression of bio-mimetic propulsion, especially underwater propulsion, where some primary conceptions are touched upon. Second, the understanding of flapping foils, considered as one of the most efficient cruise styles of aquatic animals, is introduced, where the effect of kinematics and the shape and flexibility of foils on generating thrust are elucidated respectively. Fast-start propulsion is always exhibited when predator behaviour occurs, and we provide an explicit introduction of corresponding zoological experiments and numerical simulations. We also provide some predictions about underwater bio-mimetic propulsion.

Biomimetic fabrication of a three-level hierarchical calcium phosphate/collagen/hydroxyapatite scaffold for bone tissue engineering.

PubMed

Zhou, Changchun; Ye, Xingjiang; Fan, Yujiang; Ma, Liang; Tan, Yanfei; Qing, Fangzu; Zhang, Xingdong

2014-09-01

A three-level hierarchical calcium phosphate/collagen/hydroxyapatite (CaP/Col/HAp) scaffold for bone tissue engineering was developed using biomimetic synthesis. Porous CaP ceramics were first prepared as substrate materials to mimic the porous bone structure. A second-level Col network was then composited into porous CaP ceramics by vacuum infusion. Finally, a third-level HAp layer was achieved by biomimetic mineralization. The three-level hierarchical biomimetic scaffold was characterized using scanning electron microscopy, energy-dispersive x-ray spectra, x-ray diffraction and Fourier transform infrared spectroscopy, and the mechanical properties of the scaffold were evaluated using dynamic mechanical analysis. The results show that this scaffold exhibits a similar structure and composition to natural bone tissues. Furthermore, this three-level hierarchical biomimetic scaffold showed enhanced mechanical strength compared with pure porous CaP scaffolds. The biocompatibility and osteoinductivity of the biomimetic scaffolds were evaluated using in vitro and in vivo tests. Cell culture results indicated the good biocompatibility of this biomimetic scaffold. Faster and increased bone formation was observed in these scaffolds following a six-month implantation in the dorsal muscles of rabbits, indicating that this biomimetic scaffold exhibits better osteoinductivity than common CaP scaffolds.

Enhanced photothermal therapy of biomimetic polypyrrole nanoparticles through improving blood flow perfusion.

PubMed

Wang, Xuejun; Li, Haichun; Liu, Xianping; Tian, Ye; Guo, Huishu; Jiang, Ting; Luo, Zimiao; Jin, Kai; Kuai, Xinping; Liu, Yao; Pang, Zhiqing; Yang, Wuli; Shen, Shun

2017-10-01

In this study, we reported a strategy to improve delivery efficiency of a long-circulation biomimetic photothermal nanoagent for enhanced photothermal therapy through selectively dilating tumor vasculature. By using a simply nanocoating technology, a biomimetic layer of natural red blood cell (RBC) membranes was camouflaged on the surface of photothermal polypyrrole nanoparticles (PPy@RBC NPs). The erythrocyte-mimicking PPy NPs inherited the immune evasion ability from natural RBC resulting in superior prolonged blood retention time. Additionally, excellent photothermal and photoacoustic imaging functionalities were all retained attributing to PPy NPs cores. To further improve the photothermal outcome, the endothelin A (ET A ) receptor antagonist BQ123 was jointly employed to regulate tumor microenvironment. The BQ123 could induce tumor vascular relaxation and increase blood flow perfusion through modulating an ET-1/ET A transduction pathway and blocking the ET A receptor, whereas the vessel perfusion of normal tissues was not altered. Through our well-designed tactic, the concentration of biomimetic PPy NPs in tumor site was significantly improved when administered systematically. The study documented that the antitumor efficiency of biomimetic PPy NPs combined with specific antagonist BQ123 was particularly prominent and was superior to biomimetic PPy NPs (P < 0.05) and PEGylated PPy NPs with BQ123 (P < 0.01), showing that the greatly enhanced photothermal treatment could be achieved with low-dose administration of photothermal agents. Our findings would provide a promising procedure for other similar enhanced photothermal treatment by blocking ET A receptor to dramatically increase the delivery of biomimetic photothermal nanomaterials. Copyright © 2017 Elsevier Ltd. All rights reserved.

Biomimetic Dissolution: A Tool to Predict Amorphous Solid Dispersion Performance.

PubMed

Puppolo, Michael M; Hughey, Justin R; Dillon, Traciann; Storey, David; Jansen-Varnum, Susan

2017-11-01

The presented study describes the development of a membrane permeation non-sink dissolution method that can provide analysis of complete drug speciation and emulate the in vivo performance of poorly water-soluble Biopharmaceutical Classification System class II compounds. The designed membrane permeation methodology permits evaluation of free/dissolved/unbound drug from amorphous solid dispersion formulations with the use of a two-cell apparatus, biorelevant dissolution media, and a biomimetic polymer membrane. It offers insight into oral drug dissolution, permeation, and absorption. Amorphous solid dispersions of felodipine were prepared by hot melt extrusion and spray drying techniques and evaluated for in vitro performance. Prior to ranking performance of extruded and spray-dried felodipine solid dispersions, optimization of the dissolution methodology was performed for parameters such as agitation rate, membrane type, and membrane pore size. The particle size and zeta potential were analyzed during dissolution experiments to understand drug/polymer speciation and supersaturation sustainment of felodipine solid dispersions. Bland-Altman analysis was performed to measure the agreement or equivalence between dissolution profiles acquired using polymer membranes and porcine intestines and to establish the biomimetic nature of the treated polymer membranes. The utility of the membrane permeation dissolution methodology is seen during the evaluation of felodipine solid dispersions produced by spray drying and hot melt extrusion. The membrane permeation dissolution methodology can suggest formulation performance and be employed as a screening tool for selection of candidates to move forward to pharmacokinetic studies. Furthermore, the presented model is a cost-effective technique.

Biomimetic modelling.

PubMed Central

Vincent, Julian F V

2003-01-01

Biomimetics is seen as a path from biology to engineering. The only path from engineering to biology in current use is the application of engineering concepts and models to biological systems. However, there is another pathway: the verification of biological mechanisms by manufacture, leading to an iterative process between biology and engineering in which the new understanding that the engineering implementation of a biological system can bring is fed back into biology, allowing a more complete and certain understanding and the possibility of further revelations for application in engineering. This is a pathway as yet unformalized, and one that offers the possibility that engineers can also be scientists. PMID:14561351

Biomimetic Cross-Reactive Sensor Arrays: Prospects in Biodiagnostics

PubMed Central

Fitzgerald, J. E.

2016-01-01

Biomimetic cross-reactive sensor arrays have been used to detect and analyze a wide variety of vapour and liquid components in applications such as food science, public health and safety, and diagnostics. As technology has advanced over the past three decades, these systems have become selective, sensitive, and affordable. Currently, the need for non-invasive and accurate devices for early disease diagnosis remains a challenge. This review provides an overview of the various types of Biomimetic cross-reactive sensor arrays (also referred to as electronic noses and tongues in the literature), their current use and future directions, and an outlook for future technological development. PMID:28217300

Challenges in Commercializing Biomimetic Membranes.

PubMed

Perry, Mark; Madsen, Steen Ulrik; Jørgensen, Tine; Braekevelt, Sylvie; Lauritzen, Karsten; Hélix-Nielsen, Claus

2015-11-05

The discovery of selective water channel proteins-aquaporins-has prompted growing interest in using these proteins, as the building blocks for designing new types of membranes. However, as with any other new and potentially disruptive technology, barriers for successful market entry exist. One category includes customer-related barriers, which can be influenced to some extent. Another category includes market-technical-related barriers, which can be very difficult to overcome by an organization/company aiming at successfully introducing their innovation on the market-in particular if both the organization and the technology are at early stages. Often, one faces barriers from both these categories at the same time, which makes it necessary to gain insight of the particular market when introducing a new innovative product. In this review we present the basic concepts and discuss some of these barriers and challenges associated with introducing biomimetic aquaporin membranes. These include technical issues in membrane production and product testing. Then we discuss possible business models for introducing new technologies in general, followed by a presentation of beach-head market segments relevant for biomimetic aquaporin membranes.

PEM Fuel Cells Redesign Using Biomimetic and TRIZ Design Methodologies

NASA Astrophysics Data System (ADS)

Fung, Keith Kin Kei

Two formal design methodologies, biomimetic design and the Theory of Inventive Problem Solving, TRIZ, were applied to the redesign of a Proton Exchange Membrane (PEM) fuel cell. Proof of concept prototyping was performed on two of the concepts for water management. The liquid water collection with strategically placed wicks concept demonstrated the potential benefits for a fuel cell. Conversely, the periodic flow direction reversal concepts might cause a potential reduction water removal from a fuel cell. The causes of this water removal reduction remain unclear. In additional, three of the concepts generated with biomimetic design were further studied and demonstrated to stimulate more creative ideas in the thermal and water management of fuel cells. The biomimetic design and the TRIZ methodologies were successfully applied to fuel cells and provided different perspectives to the redesign of fuel cells. The methodologies should continue to be used to improve fuel cells.

Bottom-Up Synthesis and Sensor Applications of Biomimetic Nanostructures

PubMed Central

Wang, Li; Sun, Yujing; Li, Zhuang; Wu, Aiguo; Wei, Gang

2016-01-01

The combination of nanotechnology, biology, and bioengineering greatly improved the developments of nanomaterials with unique functions and properties. Biomolecules as the nanoscale building blocks play very important roles for the final formation of functional nanostructures. Many kinds of novel nanostructures have been created by using the bioinspired self-assembly and subsequent binding with various nanoparticles. In this review, we summarized the studies on the fabrications and sensor applications of biomimetic nanostructures. The strategies for creating different bottom-up nanostructures by using biomolecules like DNA, protein, peptide, and virus, as well as microorganisms like bacteria and plant leaf are introduced. In addition, the potential applications of the synthesized biomimetic nanostructures for colorimetry, fluorescence, surface plasmon resonance, surface-enhanced Raman scattering, electrical resistance, electrochemistry, and quartz crystal microbalance sensors are presented. This review will promote the understanding of relationships between biomolecules/microorganisms and functional nanomaterials in one way, and in another way it will guide the design and synthesis of biomimetic nanomaterials with unique properties in the future. PMID:28787853

Fish and robots swimming together: attraction towards the robot demands biomimetic locomotion

PubMed Central

Marras, Stefano; Porfiri, Maurizio

2012-01-01

The integration of biomimetic robots in a fish school may enable a better understanding of collective behaviour, offering a new experimental method to test group feedback in response to behavioural modulations of its ‘engineered’ member. Here, we analyse a robotic fish and individual golden shiners (Notemigonus crysoleucas) swimming together in a water tunnel at different flow velocities. We determine the positional preference of fish with respect to the robot, and we study the flow structure using a digital particle image velocimetry system. We find that biomimetic locomotion is a determinant of fish preference as fish are more attracted towards the robot when its tail is beating rather than when it is statically immersed in the water as a ‘dummy’. At specific conditions, the fish hold station behind the robot, which may be due to the hydrodynamic advantage obtained by swimming in the robot's wake. This work makes a compelling case for the need of biomimetic locomotion in promoting robot–animal interactions and it strengthens the hypothesis that biomimetic robots can be used to study and modulate collective animal behaviour. PMID:22356819

Fish and robots swimming together: attraction towards the robot demands biomimetic locomotion.

PubMed

Marras, Stefano; Porfiri, Maurizio

2012-08-07

The integration of biomimetic robots in a fish school may enable a better understanding of collective behaviour, offering a new experimental method to test group feedback in response to behavioural modulations of its 'engineered' member. Here, we analyse a robotic fish and individual golden shiners (Notemigonus crysoleucas) swimming together in a water tunnel at different flow velocities. We determine the positional preference of fish with respect to the robot, and we study the flow structure using a digital particle image velocimetry system. We find that biomimetic locomotion is a determinant of fish preference as fish are more attracted towards the robot when its tail is beating rather than when it is statically immersed in the water as a 'dummy'. At specific conditions, the fish hold station behind the robot, which may be due to the hydrodynamic advantage obtained by swimming in the robot's wake. This work makes a compelling case for the need of biomimetic locomotion in promoting robot-animal interactions and it strengthens the hypothesis that biomimetic robots can be used to study and modulate collective animal behaviour.

Biomimetics of Bone Implants: The Regenerative Road.

PubMed

Brett, Elizabeth; Flacco, John; Blackshear, Charles; Longaker, Michael T; Wan, Derrick C

2017-01-01

The current strategies for healing bone defects are numerous and varied. At the core of each bone healing therapy is a biomimetic mechanism, which works to enhance bone growth. These range from porous scaffolds, bone mineral usage, collagen, and glycosaminoglycan substitutes to transplanted cell populations. Bone defects face a range of difficulty in their healing, given the composite of dense outer compact bone and blood-rich inner trabecular bone. As such, the tissue possesses a number of inherent characteristics, which may be clinically harnessed as promoters of bone healing. These include mechanical characteristics, mineral composition, native collagen content, and cellular fraction of bone. This review charts multiple biomimetic strategies to help heal bony defects in large and small osseous injury sites, with a special focus on cell transplantation.

Biomimetic Oxygen-Evolving Photobacteria Based on Amino Acid and Porphyrin Hierarchical Self-Organization.

PubMed

Liu, Kai; Zhang, Han; Xing, Ruirui; Zou, Qianli; Yan, Xuehai

2017-12-26

Biomimetic organization provides a promising strategy to develop functional materials and understand biological processes. However, how to mimic complex biological systems using simple biomolecular units remains a great challenge. Herein, we design and fabricate a biomimetic cyanobacteria model based on self-integration of small bioinspired molecules, including amphiphilic amino acid, 3,4-dihydroxyphenylalanine (DOPA), and metalloporphyrin and cobalt oxide nanoparticles (Co 3 O 4 NPs), with the assistance of chemical conjugation and molecular self-assembly. The assembled amino acid fiber can be modified by DOPA to form covalently bound DOPA melanin containing hydroxyl and quinone species via Schiff base reaction. The adhering template can further tune the self-assembly of metalloporphyrin and Co 3 O 4 NPs into J-aggregation and dispersive distribution, respectively, mainly via coordination binding. Metalloporphyrin molecules in the resulting hybrid fibers capture light; quinone species accept the excited electrons, and Co 3 O 4 NPs catalyze water oxidation. Thus, the essential components of the photosystem-II protein complex in cyanobacteria are simplified and engineered into a simple framework, still retaining a similar photosynthetic mechanism. In addition, this architecture leads to efficient coupling of antenna, quinone-type reaction center, and photocatalyst, which increases the flux of light energy from antenna to reaction center for charge separation, resulting in enhanced oxygen evolution rate with excellent sustainability.

Biological activity of lactoferrin-functionalized biomimetic hydroxyapatite nanocrystals

PubMed Central

Nocerino, Nunzia; Fulgione, Andrea; Iannaccone, Marco; Tomasetta, Laura; Ianniello, Flora; Martora, Francesca; Lelli, Marco; Roveri, Norberto; Capuano, Federico; Capparelli, Rosanna

2014-01-01

The emergence of bacterial strains resistant to antibiotics is a general public health problem. Progress in developing new molecules with antimicrobial properties has been made. In this study, we evaluated the biological activity of a hybrid nanocomposite composed of synthetic biomimetic hydroxyapatite surface-functionalized by lactoferrin (LF-HA). We evaluated the antimicrobial, anti-inflammatory, and antioxidant properties of LF-HA and found that the composite was active against both Gram-positive and Gram-negative bacteria, and that it modulated proinflammatory and anti-inflammatory responses and enhanced antioxidant properties as compared with LF alone. These results indicate the possibility of using LF-HA as an antimicrobial system and biomimetic hydroxyapatite as a candidate for innovative biomedical applications. PMID:24623976

Osteoblast response to porous titanium and biomimetic surface: In vitro analysis.

PubMed

Prado, Renata Falchete do; de Oliveira, Fernanda Saraiva; Nascimento, Rodrigo Dias; de Vasconcellos, Luana Marotta Reis; Carvalho, Yasmin Rodarte; Cairo, Carlos Alberto Alves

2015-01-01

This study analyzed the behavior of human osteoblasts cultured on porous titanium specimens, with and without biomimetic treatment, compared to dense titanium. The experiment had seven groups: Group 1: cells cultured on polystyrene of culture plate wells; Group 2: cells cultured on dense titanium specimen; Group 3: specimen with 33.79% of pores; Group 4: 41.79% of pores; Groups 5, 6 and 7: specimens similar to groups 2, 3 and 4, yet with biomimetic treatment. Real time-polymerase chain reaction with reverse transcription of the following genes was performed: prostaglandin E2 synthase, integrin β1, osterix, Runx2, Interleukin 6, macrophage colony stimulating factor, apolipoprotein E and others. The study achieved data on cell adhesion, growth and viability, total protein content, alkaline phosphatase activity and quantity of mineralized nodule formations. Data were statistically evaluated. Adherent cells and alkaline phosphatase activity were similar in titanium specimens, regardless of the groups. Biomimetic treatment reduced the total protein activity and the viability of tested cells. Most tested genes had statistically similar expression in all groups. The tested porosities did not cause alterations in osteoblast behavior and the biomimetic treatment impaired the biocompatibility of titanium causing cytotoxicity. Copyright © 2015 Elsevier B.V. All rights reserved.

Molecular Approach to Conjugated Polymers with Biomimetic Properties.

PubMed

Baek, Paul; Voorhaar, Lenny; Barker, David; Travas-Sejdic, Jadranka

2018-06-13

The field of bioelectronics involves the fascinating interplay between biology and human-made electronics. Applications such as tissue engineering, biosensing, drug delivery, and wearable electronics require biomimetic materials that can translate the physiological and chemical processes of biological systems, such as organs, tissues. and cells, into electrical signals and vice versa. However, the difference in the physical nature of soft biological elements and rigid electronic materials calls for new conductive or electroactive materials with added biomimetic properties that can bridge the gap. Soft electronics that utilize organic materials, such as conjugated polymers, can bring many important features to bioelectronics. Among the many advantages of conjugated polymers, the ability to modulate the biocompatibility, solubility, functionality, and mechanical properties through side chain engineering can alleviate the issues of mechanical mismatch and provide better interface between the electronics and biological elements. Additionally, conjugated polymers, being both ionically and electrically conductive through reversible doping processes provide means for direct sensing and stimulation of biological processes in cells, tissues, and organs. In this Account, we focus on our recent progress in molecular engineering of conjugated polymers with tunable biomimetic properties, such as biocompatibility, responsiveness, stretchability, self-healing, and adhesion. Our approach is general and versatile, which is based on functionalization of conjugated polymers with long side chains, commonly polymeric or biomolecules. Applications for such materials are wide-ranging, where we have demonstrated conductive, stimuli-responsive antifouling, and cell adhesive biointerfaces that can respond to external stimuli such as temperature, salt concentration, and redox reactions, the processes that in turn modify and reversibly switch the surface properties. Furthermore, utilizing the

On the interaction of the highly charged peptides casocidins with biomimetic membranes.

PubMed

Becucci, Lucia; Aloisi, Giovanni; Scaloni, Andrea; Caira, Simonetta; Guidelli, Rolando

2018-04-19

Casocidin I and II (CI and CII) are structurally related antimicrobial peptides made of 39 and 31 amino acids, respectively, which derive from natural proteolytic processing of α s2 -casein and adopt an ordered α-helical structure in biomimetic membranes. Their putative membrane-permeabilizing activity was investigated at Hg-supported self-assembled monolayers (SAMs) and at tethered bilayer lipid membranes (tBLMs); the latter consisted of a monolayer of 2,3,di-O-phytanyl-sn-glycerol-1-tetraethylene-glycol-d,l-α lipoic acid ester thiolipid (DPTL), with a dioleoylphosphatidylcholine (DOPC) or dioleoylphosphatidylserine (DOPS) monolayer on top of it. Interaction of CI and CII with these biomimetic membranes was studied by four electrochemical techniques at pH 3, 5.4 and 6.8. Peptide incorporation in tBLMs was attempted via scans of electrochemical impedance spectra. Experiments demonstrated that CI and CII penetrate SAMs as well as the distal DOPC monolayer of DPTL/DOPC tBLMs, but not the proximal phytanyl monolayer, with the only exception of CII at pH 5.4. Conversely, CII permeabilized DPTL/DOPS tBLMs to a moderate extent at all investigated pH values by forming holes across the membrane, but not ion channels. Structural distribution of charged residues seemed to prevent CII from having a hydrophobic side of the α-helix capable of stabilizing a regular ion channel in the lipid matrix. Copyright © 2018 Elsevier B.V. All rights reserved.

How capping protein enhances actin filament growth and nucleation on biomimetic beads.

PubMed

Wang, Ruizhe; Carlsson, Anders E

2015-11-25

Capping protein (CP), which caps the growing ends of actin filaments, accelerates actin-based motility. Recent experiments on biomimetic beads have shown that CP also enhances the rate of actin filament nucleation. Proposed explanations for these phenomena include (i) the actin funneling hypothesis (AFH), in which the presence of CP increases the free-actin concentration, and (ii) the monomer gating model, in which CP binding to actin filament barbed ends makes more monomers available for filament nucleation. To establish how CP increases the rates of filament elongation and nucleation on biomimetic beads, we perform a quantitative modeling analysis of actin polymerization, using rate equations that include actin filament nucleation, polymerization and capping, as modified by monomer depletion near the surface of the bead. With one adjustable parameter, our simulation results match previously measured time courses of polymerized actin and filament number. The results support a version of the AFH where CP increases the local actin monomer concentration at the bead surface, but leaves the global free-actin concentration nearly constant. Because the rate of filament nucleation increases with the monomer concentration, the increased local monomer concentration enhances actin filament nucleation. We derive a closed-form formula for the characteristic CP concentration where the local free-actin concentration reaches half the bulk value, and find it to be comparable to the global Arp2/3 complex concentration. We also propose an experimental protocol for distinguishing branching nucleation of filaments from spontaneous nucleation.

Wear Behavior of Medium Carbon Steel with Biomimetic Surface Under Starved Lubricated Conditions

NASA Astrophysics Data System (ADS)

Zhang, Zhihui; Shao, Feixian; Liang, Yunhong; Lin, Pengyu; Tong, Xin; Ren, Luquan

2017-07-01

Friction and wear under starved lubrication condition are both key life-related factors for mechanical performance of many structural parts. In this paper, different surface morphologies on medium carbon steel were fabricated using laser, inspired by the surface coupling effect of biological system. The friction and sliding wear behaviors of biomimetic specimens (characterized by convex and concave units on the specimen surface) were studied under starved lubrication condition. The stress distribution on different sliding surfaces under sliding friction was studied using finite element method. The results showed that the tribological performance of studied surfaces under starved lubrication condition depended not only on the surface morphology but also on the structure of biomimetic units below surface (subsurface structure). The friction coefficient of biomimetic surface was effectively reduced by the concave unit depth, while the refined microstructure with higher hardness led to the much better wear resistance. In addition to lubricant reserving and wear debris trapping effect derived from the surface concave morphology, it was believed that the well-formed subsurface structure of biomimetic units could carry much heavy loads against tribopair, which enhanced the function of surface topography and resulted in complementary lubrication in the wear contact area. The uniform stress distribution on the entire biomimetic surface also played an important role in stabilizing the friction coefficient and reducing the wear cracks.

Biomimetic materials in the utility industry: A program plan for research opportunities, volume 2. Final report

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

Richman, R.H.; McNaughton, W.P.

1996-09-01

This report is the second of a two-volume set addressing the state-of-the-art and outlook for the application of biomimetic materials. The first volume examined achievements in mimicking novel aspects of biological systems in five broad categories: (1) Mimicking of Natural Material Designs, (2) Biomimetic Materials Processing, (3) Artificial Photosynthesis, (4) Biomimetic Molecular Electronics, and (5) Biomimetic Catalysis. Each topic was examined as to current activities and approaches, key aspects, unresolved issues, and implications for the power industry. Key researchers, their organizations, the main thrusts of investigation, achievements, and funding agencies were also summarized. This volume highlights opportunities for future researchmore » activities in biomimetics that could be valuable to the U.S. utility industry. Nineteen specific research projects have been identified. These opportunities are outlined in four classes: (1) technology awareness, (2) modeling and experimental studies, (3) state-of-the-art and outlook studies: developing experimental plans, and (4) concept feasibility studies.« less

A New Absorbable Synthetic Substitute With Biomimetic Design for Dural Tissue Repair.

PubMed

Shi, Zhidong; Xu, Tao; Yuan, Yuyu; Deng, Kunxue; Liu, Man; Ke, Yiquan; Luo, Chengyi; Yuan, Tun; Ayyad, Ali

2016-04-01

Dural repair products are evolving from animal tissue-derived materials to synthetic materials as well as from inert to absorbable features; most of them lack functional and structural characteristics compared with the natural dura mater. In the present study, we evaluated the properties and tissue repair performance of a new dural repair product with biomimetic design. The biomimetic patch exhibits unique three-dimensional nonwoven microfiber structure with good mechanical strength and biocompatibility. The animal study showed that the biomimetic patch and commercially synthetic material group presented new subdural regeneration at 90 days, with low level inflammatory response and minimal to no adhesion formation detected at each stage. In the biological material group, no new subdural regeneration was observed and severe adhesion between the implant and the cortex occurred at each stage. In clinical case study, there was no cerebrospinal fluid leakage, and all the postoperation observations were normal. The biomimetic structure and proper rate of degradation of the new absorbable dura substitute can guide the meaningful reconstruction of the dura mater, which may provide a novel approach for dural defect repair. Copyright © 2015 International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.

Biomimetics in the design of a robotic exoskeleton for upper limb therapy

NASA Astrophysics Data System (ADS)

Baniqued, Paul Dominick E.; Dungao, Jade R.; Manguerra, Michael V.; Baldovino, Renann G.; Abad, Alexander C.; Bugtai, Nilo T.

2018-02-01

Current methodologies in designing robotic exoskeletons for upper limb therapy simplify the complex requirements of the human anatomy. As a result, such devices tend to compromise safety and biocompatibility with the intended user. However, a new design methodology uses biological analogues as inspiration to address these technical issues. This approach follows that of biomimetics, a design principle that uses the extraction and transfer of useful information from natural morphologies and processes to solve technical design issues. In this study, a biomimetic approach in the design of a 5-degree-of-freedom robotic exoskeleton for upper limb therapy was performed. A review of biomimetics was first discussed along with its current contribution to the design of rehabilitation robots. With a proposed methodological framework, the design for an upper limb robotic exoskeleton was generated using CATIA software. The design was inspired by the morphology of the bones and the muscle force transmission of the upper limbs. Finally, a full design assembly presented had integrated features extracted from the biological analogue. The successful execution of a biomimetic design methodology made a case in providing safer and more biocompatible robots for rehabilitation.

Challenges in Commercializing Biomimetic Membranes

PubMed Central

Perry, Mark; Madsen, Steen Ulrik; Jørgensen, Tine; Braekevelt, Sylvie; Lauritzen, Karsten; Hélix-Nielsen, Claus

2015-01-01

The discovery of selective water channel proteins—aquaporins—has prompted growing interest in using these proteins, as the building blocks for designing new types of membranes. However, as with any other new and potentially disruptive technology, barriers for successful market entry exist. One category includes customer-related barriers, which can be influenced to some extent. Another category includes market-technical-related barriers, which can be very difficult to overcome by an organization/company aiming at successfully introducing their innovation on the market—in particular if both the organization and the technology are at early stages. Often, one faces barriers from both these categories at the same time, which makes it necessary to gain insight of the particular market when introducing a new innovative product. In this review we present the basic concepts and discuss some of these barriers and challenges associated with introducing biomimetic aquaporin membranes. These include technical issues in membrane production and product testing. Then we discuss possible business models for introducing new technologies in general, followed by a presentation of beach-head market segments relevant for biomimetic aquaporin membranes. PMID:26556379

Biocatalysis and biomimetics

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

Burrington, J.D.; Clark, D.S.

1989-01-01

This book presents recent advances in catalytic science and biotechnology. The chapters illustrate how many of the key challenges in biotechnology can be addressed by bringing together traditionally separate disciplines within chemistry and biology. The authors focus on emerging enabling technologies at the interfaces of catalysis and biology that will provide new opportunities for the chemicals industries. Key aspects to be presented within this major theme of catalysis and biotechnology are biomimetics and hybrid catalysts, biocatalytic applications of computers and expert systems, enzyme solid-state structure and immobilization, enzyme structure-activity relationships, and the use of enzymes under novel conditions.

Biomimetic actuators using electroactive polymers (EAP) as artificial muscles

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph

2006-01-01

Evolution has resolved many of nature's challenges leading to lasting solutions with maximal performance and effective use of resources. Nature's inventions have always inspired human achievements leading to effective materials, structures, tools, mechanisms, processes, algorithms, methods, systems and many other benefits. The field of mimicking nature is known as Biomimetics and one of its topics includes electroactive polymers that gain the moniker artificial muscles. Integrating EAP with embedded sensors, self-repair and many other capabilities that are used in composite materials can add greatly to the capability of smart biomimetic systems. Such development would enable fascinating possibilities potentially turning science fiction ideas into engineering reality.

Biomimetic coating of magnesium alloy for enhanced corrosion resistance and calcium phosphate deposition.

PubMed

Cui, W; Beniash, E; Gawalt, E; Xu, Z; Sfeir, C

2013-11-01

Degradable metals have been suggested as biomaterials with revolutionary potential for bone-related therapies. Of these candidate metals, magnesium alloys appear to be particularly attractive candidates because of their non-toxicity and outstanding mechanical properties. Despite their having been widely studied as orthopedic implants for bone replacement/regeneration, their undesirably rapid corrosion rate under physiological conditions has limited their actual clinical application. This study reports the use of a novel biomimetic peptide coating for Mg alloys to improve the alloy corrosion resistance. A 3DSS biomimetic peptide is designed based on the highly acidic, bioactive bone and dentin extracellular matrix protein, phosphophoryn. Surface characterization techniques (scanning electron microscopy, energy dispersive X-ray spectroscopy and diffuse-reflectance infrared spectroscopy) confirmed the feasibility of coating the biomimetic 3DSS peptide onto Mg alloy AZ31B. The 3DSS peptide was also used as a template for calcium phosphate deposition on the surface of the alloy. The 3DSS biomimetic peptide coating presented a protective role of AZ31B in both hydrogen evolution and electrochemical corrosion tests. Copyright © 2013. Published by Elsevier Ltd.

A supramolecular biomimetic skin combining a wide spectrum of mechanical properties and multiple sensory capabilities.

PubMed

Lei, Zhouyue; Wu, Peiyi

2018-03-19

Biomimetic skin-like materials, capable of adapting shapes to variable environments and sensing external stimuli, are of great significance in a wide range of applications, including artificial intelligence, soft robotics, and smart wearable devices. However, such highly sophisticated intelligence has been mainly found in natural creatures while rarely realized in artificial materials. Herein, we fabricate a type of biomimetic iontronics to imitate natural skins using supramolecular polyelectrolyte hydrogels. The dynamic viscoelastic networks provide the biomimetic skin with a wide spectrum of mechanical properties, including flexible reconfiguration ability, robust elasticity, extremely large stretchability, autonomous self-healability, and recyclability. Meanwhile, polyelectrolytes' ionic conductivity allows multiple sensory capabilities toward temperature, strain, and stress. This work provides not only insights into dynamic interactions and sensing mechanism of supramolecular iontronics, but may also promote the development of biomimetic skins with sophisticated intelligence similar to natural skins.

Biomimetic membrane arrays on cast hydrogel supports.

PubMed

Roerdink Lander, Monique; Ibragimova, Sania; Rein, Christian; Vogel, Jörg; Stibius, Karin; Geschke, Oliver; Perry, Mark; Hélix-Nielsen, Claus

2011-06-07

Lipid bilayers are intrinsically fragile and require mechanical support in technical applications based on biomimetic membranes. Tethering the lipid bilayer membranes to solid substrates, either directly through covalent or ionic substrate-lipid links or indirectly on substrate-supported cushions, provides mechanical support but at the cost of small molecule transport through the membrane-support sandwich. To stabilize biomimetic membranes while allowing transport through a membrane-support sandwich, we have investigated the feasibility of using an ethylene tetrafluoroethylene (ETFE)/hydrogel sandwich as the support. The sandwich is realized as a perforated surface-treated ETFE film onto which a hydrogel composite support structure is cast. We report a simple method to prepare arrays of lipid bilayer membranes with low intrinsic electrical conductance on the highly permeable, self-supporting ETFE/hydrogel sandwiches. We demonstrate how the ETFE/hydrogel sandwich support promotes rapid self-thinning of lipid bilayers suitable for hosting membrane-spanning proteins.

Kirigami design and fabrication for biomimetic robotics

NASA Astrophysics Data System (ADS)

Rossiter, Jonathan; Sareh, Sina

2014-03-01

Biomimetics faces a continual challenge of how to bridge the gap between what Nature has so effectively evolved and the current tools and materials that engineers and scientists can exploit. Kirigami, from the Japanese `cut' and `paper', is a method of design where laminar materials are cut and then forced out-of-plane to yield 3D structures. Kirimimetic design provides a convenient and relatively closed design space within which to replicate some of the most interesting niche biological mechanisms. These include complex flexing organelles such as cilia in algae, energy storage and buckled structures in plants, and organic appendages that actuate out-of-plane such as the myoneme of the Vorticella protozoa. Where traditional kirigami employs passive materials which must be forced to transition to higher dimensions, we can exploit planar smart actuators and artificial muscles to create self-actuating kirigami structures. Here we review biomimetics with respect to the kirigami design and fabrication methods and examine how smart materials, including electroactive polymers and shape memory polymers, can be used to realise effective biomimetic components for robotic, deployable structures and engineering systems. One-way actuation, for example using shape memory polymers, can yield complete self-deploying structures. Bi-directional actuation, in contrast, can be exploited to mimic fundamental biological mechanisms such as thrust generation and fluid control. We present recent examples of kirigami robotic mechanisms and actuators and discuss planar fabrication methods, including rapid prototyping and 3D printing, and how current technologies, and their limitations, affect Kirigami robotics.

Biomimetic approach to cardiac tissue engineering.

PubMed

Radisic, M; Park, H; Gerecht, S; Cannizzaro, C; Langer, R; Vunjak-Novakovic, G

2007-08-29

Here, we review an approach to tissue engineering of functional myocardium that is biomimetic in nature, as it involves the use of culture systems designed to recapitulate some aspects of the actual in vivo environment. To mimic the capillary network, subpopulations of neonatal rat heart cells were cultured on a highly porous elastomer scaffold with a parallel array of channels perfused with culture medium. To mimic oxygen supply by haemoglobin, the culture medium was supplemented with a perfluorocarbon (PFC) emulsion. Constructs cultivated in the presence of PFC contained higher amounts of DNA and cardiac markers and had significantly better contractile properties than control constructs cultured without PFC. To induce synchronous contractions of cultured constructs, electrical signals mimicking those in native heart were applied. Over only 8 days of cultivation, electrical stimulation induced cell alignment and coupling, markedly increased the amplitude of synchronous construct contractions and resulted in a remarkable level of ultrastructural organization. The biomimetic approach is discussed in the overall context of cardiac tissue engineering, and the possibility to engineer functional human cardiac grafts based on human stem cells.

Biomimetic Strategies for Sensing Biological Species

PubMed Central

Hussain, Munawar; Wackerlig, Judith; Lieberzeit, Peter A.

2013-01-01

The starting point of modern biosensing was the application of actual biological species for recognition. Increasing understanding of the principles underlying such recognition (and biofunctionality in general), however, has triggered a dynamic field in chemistry and materials sciences that aims at joining the best of two worlds by combining concepts derived from nature with the processability of manmade materials, e.g., sensitivity and ruggedness. This review covers different biomimetic strategies leading to highly selective (bio)chemical sensors: the first section covers molecularly imprinted polymers (MIP) that attempt to generate a fully artificial, macromolecular mold of a species in order to detect it selectively. A different strategy comprises of devising polymer coatings to change the biocompatibility of surfaces that can also be used to immobilized natural receptors/ligands and thus stabilize them. Rationally speaking, this leads to self-assembled monolayers closely resembling cell membranes, sometimes also including bioreceptors. Finally, this review will highlight some approaches to generate artificial analogs of natural recognition materials and biomimetic approaches in nanotechnology. It mainly focuses on the literature published since 2005. PMID:25587400

Effect of medium on friction and wear properties of compacted graphite cast iron processed by biomimetic coupling laser remelting process

NASA Astrophysics Data System (ADS)

Guo, Qing-chun; Zhou, Hong; Wang, Cheng-tao; Zhang, Wei; Lin, Peng-yu; Sun, Na; Ren, Luquan

2009-04-01

Stimulated by the cuticles of soil animals, an attempt to improve the wear resistance of compact graphite cast iron (CGI) with biomimetic units on the surface was made by using a biomimetic coupled laser remelting process in air and various thicknesses water film, respectively. The microstructures of biomimetic units were examined by scanning electron microscope and X-ray diffraction was used to describe the microstructure and identify the phases in the melted zone. Microhardness was measured and the wear behaviors of biomimetic specimens as functions of different mediums as well as various water film thicknesses were investigated under dry sliding condition, respectively. The results indicated that the microstructure zones in the biomimetic specimens processed with water film are refined compared with that processed in air and had better wear resistance increased by 60%, the microhardness of biomimetic units has been improved significantly. The application of water film provided finer microstructures and much more regular grain shape in biomimetic units, which played a key role in improving the friction properties and wear resistance of CGI.

UV photofunctionalization promotes nano-biomimetic apatite deposition on titanium

PubMed Central

Saita, Makiko; Ikeda, Takayuki; Yamada, Masahiro; Kimoto, Katsuhiko; Lee, Masaichi Chang-Il; Ogawa, Takahiro

2016-01-01

Background Although biomimetic apatite coating is a promising way to provide titanium with osteoconductivity, the efficiency and quality of deposition is often poor. Most titanium implants have microscale surface morphology, and an addition of nanoscale features while preserving the micromorphology may provide further biological benefit. Here, we examined the effect of ultraviolet (UV) light treatment of titanium, or photofunctionalization, on the efficacy of biomimetic apatite deposition on titanium and its biological capability. Methods and results Micro-roughed titanium disks were prepared by acid-etching with sulfuric acid. Micro-roughened disks with or without photofunctionalization (20-minute exposure to UV light) were immersed in simulated body fluid (SBF) for 1 or 5 days. Photofunctionalized titanium disks were superhydrophilic and did not form surface air bubbles when immersed in SBF, whereas non-photofunctionalized disks were hydrophobic and largely covered with air bubbles during immersion. An apatite-related signal was observed by X-ray diffraction on photofunctionalized titanium after 1 day of SBF immersion, which was equivalent to the one observed after 5 days of immersion of control titanium. Scanning electron microscopy revealed nodular apatite deposition in the valleys and at the inclines of micro-roughened structures without affecting the existing micro-configuration. Micro-roughened titanium and apatite-deposited titanium surfaces had similar roughness values. The attachment, spreading, settling, proliferation, and alkaline phosphate activity of bone marrow-derived osteoblasts were promoted on apatite-coated titanium with photofunctionalization. Conclusion UV-photofunctionalization of titanium enabled faster deposition of nanoscale biomimetic apatite, resulting in the improved biological capability compared to the similarly prepared apatite-deposited titanium without photofunctionalization. Photofunctionalization-assisted biomimetic apatite

Remineralization of artificial dentinal caries lesions by biomimetically modified Mineral Trioxide Aggregate

PubMed Central

Qi, Yi-pin; Li, Nan; Niu, Li-na; Primus, Carolyn M.; Ling, Jun-Qi; Pashley, David H.; Tay, Franklin R.

2011-01-01

Fluoride-releasing restorative materials are available for remineralization of enamel and root caries. However, dentin remineralization is more difficult than enamel remineralization due to the paucity of apatite seed crystallites along the lesion surface for heterogeneous crystal growth. Extracellular matrix proteins play critical roles in controlling apatite nucleation/growth in collagenous tissues. This study examined the remineralization efficacy of mineral trioxide aggregate (MTA) in phosphate-containing simulated body fluid (SBF) by incorporating polyacrylic acid and sodium tripolyphosphate as biomimetic analogs of matrix proteins for remineralizing caries-like dentin. Artificial caries-like dentin lesions incubated in SBF were remineralized over a 6-week period using MTA or MTA containing biomimetic analogs in the absence or presence of dentin adhesive application. Lesion depths and integrated mineral loss were monitored with micro-computed tomography. Ultrastructure of baseline and remineralized lesions were examined by transmission electron microscopy. Dentin remineralization was best achieved using MTA containing biomimetic analogs regardless of whether an adhesive was applied; dentinal tubules within the remineralized dentin were occluded by apatite. It is concluded that the MTA version employed in the study may be doped with biomimetic analogs for remineralization of unbonded and bonded artificial caries-like lesions in the presence of SBF. PMID:22085925

Biomimetic Synthesis of Noble Metal Nanocrystals and the Mechanism Studies

NASA Astrophysics Data System (ADS)

Ruan, Lingyan

Nanostructured materials with dimensions reaching the nanoscale possess novel properties different from their bulk counterparts. Engineering nanomaterials to exploit their improved functions show important applications in catalysis, electrocatalysis, electronics, optoelectronics, and energy devices. One of the challenges to date is to develop methods for producing nanomaterials in a controllable and predictable fashion. We seek to develop novel biomimetic synthetic protocols for programmable nanomaterial synthesis, i.e., using biomolecules with specific material recognition properties to manipulate nanomaterial morphologies and structures. Starting with three Pt binding peptides with distinct recognition properties, i.e., a Pt material specific peptide BP7A and two Pt facet specific peptides T7 (Pt {100} facet specific) and S7 (Pt {111} facet specific), we demonstrate a rational creation of Pt bipyramids, a new type of shape for Pt nanocrystals. The BP7A peptide is found to be able to introduce twinning during Pt nanocrystal growth. We use it to generate single twinned seeds for Pt nanocrystals. Together with targeted facet stabilization using T7/S7 peptides, Pt {100} bipyramid and {111} bipyramid are successfully synthesized for the first time. We further utilize the twin introducing property of the BP7A peptide to generate ultrathin Pt nanowire with high twin densities. We show that the Pt nanowire possesses higher electrocatalytic activity and durability in oxygen reduction and methanol oxidation reactions due to its one-dimensional nanostructure and the presence of dense twin defects, demonstrating the concept of defect engineering in nanocrystals as a strategy in the design of novel electrocatalyst. The organic-inorganic interface is a key issue in many fields including colloidal syntheses and biomimetics, the understanding of which can enable the design of new material synthetic strategies. We aim to understand how the Pt binding peptides modulate the

The state of the art in biomimetics.

PubMed

Lepora, Nathan F; Verschure, Paul; Prescott, Tony J

2013-03-01

Biomimetics is a research field that is achieving particular prominence through an explosion of new discoveries in biology and engineering. The field concerns novel technologies developed through the transfer of function from biological systems. To analyze the impact of this field within engineering and related sciences, we compiled an extensive database of publications for study with network-based information analysis techniques. Criteria included publications by year and journal or conference, and subject areas judged by popular and common terms in titles. Our results reveal that this research area has expanded rapidly from less than 100 papers per year in the 1990s to several thousand papers per year in the first decade of this century. Moreover, this research is having impact across a variety of research themes, spanning robotics, computer science and bioengineering. In consequence, biomimetics is becoming a leading paradigm for the development of new technologies that will potentially lead to significant scientific, societal and economic impact in the near future.

Engineering Vascularized Bone Grafts by Integrating a Biomimetic Periosteum and β-TCP Scaffold

PubMed Central

2015-01-01

Treatment of large bone defects using synthetic scaffolds remain a challenge mainly due to insufficient vascularization. This study is to engineer a vascularized bone graft by integrating a vascularized biomimetic cell-sheet-engineered periosteum (CSEP) and a biodegradable macroporous beta-tricalcium phosphate (β-TCP) scaffold. We first cultured human mesenchymal stem cells (hMSCs) to form cell sheet and human umbilical vascular endothelial cells (HUVECs) were then seeded on the undifferentiated hMSCs sheet to form vascularized cell sheet for mimicking the fibrous layer of native periosteum. A mineralized hMSCs sheet was cultured to mimic the cambium layer of native periosteum. This mineralized hMSCs sheet was first wrapped onto a cylindrical β-TCP scaffold followed by wrapping the vascularized HUVEC/hMSC sheet, thus generating a biomimetic CSEP on the β-TCP scaffold. A nonperiosteum structural cell sheets-covered β-TCP and plain β-TCP were used as controls. In vitro studies indicate that the undifferentiated hMSCs sheet facilitated HUVECs to form rich capillary-like networks. In vivo studies indicate that the biomimetic CSEP enhanced angiogenesis and functional anastomosis between the in vitro preformed human capillary networks and the mouse host vasculature. MicroCT analysis and osteocalcin staining show that the biomimetic CSEP/β-TCP graft formed more bone matrix compared to the other groups. These results suggest that the CSEP that mimics the cellular components and spatial configuration of periosteum plays a critical role in vascularization and osteogenesis. Our studies suggest that a biomimetic periosteum-covered β-TCP graft is a promising approach for bone regeneration. PMID:24858072

A novel biomimetic sonarhead using beamforming technology to mimic bat echolocation.

PubMed

Steckel, Jan; Peremans, Herbert

2012-07-01

A novel biomimetic sonarhead has been developed to allow researchers of bat echolocation behavior and biomimetic sonar to perform experiments with a system similar to the bat¿s sensory system. The bat's echolocation-related transfer function (ERTF) is implemented using an array of receivers to implement the head-related transfer function (HRTF), and an array of emitters mounted on a cylindrical manifold to implement the emission pattern of the bat. The complete system is controlled by a field-programmable gate array (FPGA) based embedded system connected through a USB interface.

Towards a real-time interface between a biomimetic model of sensorimotor cortex and a robotic arm

PubMed Central

Dura-Bernal, Salvador; Chadderdon, George L; Neymotin, Samuel A; Francis, Joseph T; Lytton, William W

2015-01-01

Brain-machine interfaces can greatly improve the performance of prosthetics. Utilizing biomimetic neuronal modeling in brain machine interfaces (BMI) offers the possibility of providing naturalistic motor-control algorithms for control of a robotic limb. This will allow finer control of a robot, while also giving us new tools to better understand the brain’s use of electrical signals. However, the biomimetic approach presents challenges in integrating technologies across multiple hardware and software platforms, so that the different components can communicate in real-time. We present the first steps in an ongoing effort to integrate a biomimetic spiking neuronal model of motor learning with a robotic arm. The biomimetic model (BMM) was used to drive a simple kinematic two-joint virtual arm in a motor task requiring trial-and-error convergence on a single target. We utilized the output of this model in real time to drive mirroring motion of a Barrett Technology WAM robotic arm through a user datagram protocol (UDP) interface. The robotic arm sent back information on its joint positions, which was then used by a visualization tool on the remote computer to display a realistic 3D virtual model of the moving robotic arm in real time. This work paves the way towards a full closed-loop biomimetic brain-effector system that can be incorporated in a neural decoder for prosthetic control, to be used as a platform for developing biomimetic learning algorithms for controlling real-time devices. PMID:26709323

Biomimetic optimization research on wind noise reduction of an asymmetric cross-section bar.

PubMed

Zhang, Yingchao; Meng, Weijiang; Fan, Bing; Tang, Wenhui

2016-01-01

In this paper, we used the principle of biomimetics to design two-dimensional and three-dimensional bar sections, and used computational fluid dynamics software to numerically simulate and analyse the aerodynamic noise, to reduce drag and noise. We used the principle of biomimetics to design the cross-section of a bar. An owl wing shape was used for the initial design of the section geometry; then the feathered form of an owl wing, the v-shaped micro-grooves of a shark's skin, the tubercles of a humpback whale's flipper, and the stripy surface of a scallop's shell were used to inspire surface features, added to the initial section and three-dimensional shape. Through computational aeroacoustic simulations, we obtained the aerodynamic characteristics and the noise levels of the models. These biomimetic models dramatically decreased noise levels.

Remineralization of artificial dentinal caries lesions by biomimetically modified mineral trioxide aggregate.

PubMed

Qi, Yi-pin; Li, Nan; Niu, Li-na; Primus, Carolyn M; Ling, Jun-Qi; Pashley, David H; Tay, Franklin R

2012-02-01

Fluoride-releasing restorative materials are available for remineralization of enamel and root caries. However, remineralization of dentin is more difficult than remineralization of enamel due to the paucity of apatite seed crystallites along the lesion surface for heterogeneous crystal growth. Extracellular matrix proteins play critical roles in controlling apatite nucleation/growth in collagenous tissues. This study examined the remineralization efficacy of mineral trioxide aggregate (MTA) in phosphate-containing simulated body fluid (SBF) by incorporating polyacrylic acid and sodium tripolyphosphate as biomimetic analogs of matrix proteins for remineralizing caries-like dentin. Artificial caries-like dentin lesions incubated in SBF were remineralized over a 6 week period using MTA alone or MTA containing biomimetic analogs in the absence or presence of dentin adhesive application. Lesion depths and integrated mineral loss were monitored with microcomputed tomography. The ultrastructure of baseline and remineralized lesions was examined by transmission electron microscopy. Dentin remineralization was best achieved using MTA containing biomimetic analogs regardless of whether an adhesive was applied; dentinal tubules within the remineralized dentin were occluded by apatite. It is concluded that the version of MTA employed in this study may be doped with biomimetic analogs for remineralization of unbonded and bonded artificial caries-like lesions in the presence of SBF. Copyright © 2011 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Bonding performance of experimental bioactive/biomimetic self-etch adhesives doped with calcium-phosphate fillers and biomimetic analogs of phosphoproteins.

PubMed

Abuna, Gabriel; Feitosa, Victor P; Correr, Americo Bortolazzo; Cama, Giuseppe; Giannini, Marcelo; Sinhoreti, Mario A; Pashley, David H; Sauro, Salvatore

2016-09-01

This study examined the bonding performance and dentin remineralization potential of an experimental adhesive containing calcium-phosphate (Ca/P) micro-fillers, and self-etching primers doped with phosphoprotein biomimetic analogs (polyacrylic acid-(PAA) and/or sodium trimetaphosphate-(TMP)). Experimental self-etching primers doped with biomimetic analogs (PAA and/or TMP), and an adhesive containing Ca(2+), PO4(-3)-releasing micro-fillers (Ca/P) were formulated. Sound human dentin specimens were bonded and cut into sticks after aging (24h or 6 months) under simulated pulpal pressure (20cm H2O), and tested for microtensile bond strength (μTBS). Results were analyzed using two-way ANOVA and Tukey's test (p<0.05). Interfacial silver nanoleakage was assessed using SEM. Remineralization of EDTA-demineralized dentin was assessed through FTIR and TEM ultrastructural analysis. Application of the Ca/P-doped adhesive with or without dentin pre-treatments with the primer containing both biomimetic analogs (PAA and TMP) promoted stable μTBS over 6 months. Conversely, μTBS of the control primer and filler-free adhesive significantly decreased after 6 months. Nanoleakage decreased within the resin-dentin interfaces created using the Ca/P-doped adhesives. EDTA-demineralized dentin specimens treated the Ca/P-doped adhesive and the primer containing PAA and TMP showed phosphate uptake (FTIR analysis), as well as deposition of needle-like crystallites at intrafibrillar level (TEM analysis). The use of Ca/P-doped self-etching adhesives applied in combination with analogs of phosphoproteins provides durable resin-dentin bonds. This approach may represent a suitable bonding strategy for remineralization of intrafibrillar dentin collagen within the resin-dentin interface. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Novel Silicone-Magnetite Composite Material Used in the Fabrication of Biomimetic Cilia

NASA Astrophysics Data System (ADS)

Carstens, B. L.; Evans, B. A.; Shields, A. R.; Su, J.; Washburn, S.; Falvo, M. R.; Superfine, R.

2008-10-01

We have developed a novel polymer-magnetite composite that we use to fabricate arrays of magnetically actuable biomimetic cilia. Biomimetic cilia are flexible nanorods 750 nm in diameter and 25 microns tall. They generate fluid flows similar to those produced by biological cilia. Polymer-magnetic nanoparticle materials such as ours are becoming increasingly useful in biomedical applications and microelectromechanical systems (MEMS). Comprised of magnetite (Fe3O4), the nanoparticles have a diameter of 5-7 nm and are complexed with a silicone copolymer and crosslinked into a flexible, magnetic solid. Amine groups make up 6-7 percent of the silicone copolymer, providing a simple means of functionalization. We present a detailed mechanical and magnetic analysis of our bulk crosslinked material. The high-aspect ratio biomimetic cilia we create with this magnetite-copolymer complex may have applications in microfluidic mixing, biofouling, and MEMS.

Biomimetic vibrissal sensing for robots

PubMed Central

Pearson, Martin J.; Mitchinson, Ben; Sullivan, J. Charles; Pipe, Anthony G.; Prescott, Tony J.

2011-01-01

Active vibrissal touch can be used to replace or to supplement sensory systems such as computer vision and, therefore, improve the sensory capacity of mobile robots. This paper describes how arrays of whisker-like touch sensors have been incorporated onto mobile robot platforms taking inspiration from biology for their morphology and control. There were two motivations for this work: first, to build a physical platform on which to model, and therefore test, recent neuroethological hypotheses about vibrissal touch; second, to exploit the control strategies and morphology observed in the biological analogue to maximize the quality and quantity of tactile sensory information derived from the artificial whisker array. We describe the design of a new whiskered robot, Shrewbot, endowed with a biomimetic array of individually controlled whiskers and a neuroethologically inspired whisking pattern generation mechanism. We then present results showing how the morphology of the whisker array shapes the sensory surface surrounding the robot's head, and demonstrate the impact of active touch control on the sensory information that can be acquired by the robot. We show that adopting bio-inspired, low latency motor control of the rhythmic motion of the whiskers in response to contact-induced stimuli usefully constrains the sensory range, while also maximizing the number of whisker contacts. The robot experiments also demonstrate that the sensory consequences of active touch control can be usefully investigated in biomimetic robots. PMID:21969690

Biomimetics for next generation materials.

PubMed

Barthelat, Francois

2007-12-15

Billions of years of evolution have produced extremely efficient natural materials, which are increasingly becoming a source of inspiration for engineers. Biomimetics-the science of imitating nature-is a growing multidisciplinary field which is now leading to the fabrication of novel materials with remarkable mechanical properties. This article discusses the mechanics of hard biological materials, and more specifically of nacre and bone. These high-performance natural composites are made up of relatively weak components (brittle minerals and soft proteins) arranged in intricate ways to achieve specific combinations of stiffness, strength and toughness (resistance to cracking). Determining which features control the performance of these materials is the first step in biomimetics. These 'key features' can then be implemented into artificial bio-inspired synthetic materials, using innovative techniques such as layer-by-layer assembly or ice-templated crystallization. The most promising approaches, however, are self-assembly and biomineralization because they will enable tight control of structures at the nanoscale. In this 'bottom-up' fabrication, also inspired from nature, molecular structures and crystals are assembled with a little or no external intervention. The resulting materials will offer new combinations of low weight, stiffness and toughness, with added functionalities such as self-healing. Only tight collaborations between engineers, chemists, materials scientists and biologists will make these 'next-generation' materials a reality.

Biomimetic vibrissal sensing for robots.

PubMed

Pearson, Martin J; Mitchinson, Ben; Sullivan, J Charles; Pipe, Anthony G; Prescott, Tony J

2011-11-12

Active vibrissal touch can be used to replace or to supplement sensory systems such as computer vision and, therefore, improve the sensory capacity of mobile robots. This paper describes how arrays of whisker-like touch sensors have been incorporated onto mobile robot platforms taking inspiration from biology for their morphology and control. There were two motivations for this work: first, to build a physical platform on which to model, and therefore test, recent neuroethological hypotheses about vibrissal touch; second, to exploit the control strategies and morphology observed in the biological analogue to maximize the quality and quantity of tactile sensory information derived from the artificial whisker array. We describe the design of a new whiskered robot, Shrewbot, endowed with a biomimetic array of individually controlled whiskers and a neuroethologically inspired whisking pattern generation mechanism. We then present results showing how the morphology of the whisker array shapes the sensory surface surrounding the robot's head, and demonstrate the impact of active touch control on the sensory information that can be acquired by the robot. We show that adopting bio-inspired, low latency motor control of the rhythmic motion of the whiskers in response to contact-induced stimuli usefully constrains the sensory range, while also maximizing the number of whisker contacts. The robot experiments also demonstrate that the sensory consequences of active touch control can be usefully investigated in biomimetic robots.

Biomimetic propulsion under random heaving conditions, using active pitch control

NASA Astrophysics Data System (ADS)

Politis, Gerasimos; Politis, Konstantinos

2014-05-01

Marine mammals travel long distances by utilizing and transforming wave energy to thrust through proper control of their caudal fin. On the other hand, manmade ships traveling in a wavy sea store large amounts of wave energy in the form of kinetic energy for heaving, pitching, rolling and other ship motions. A natural way to extract this energy and transform it to useful propulsive thrust is by using a biomimetic wing. The aim of this paper is to show how an actively pitched biomimetic wing could achieve this goal when it performs a random heaving motion. More specifically, we consider a biomimetic wing traveling with a given translational velocity in an infinitely extended fluid and performing a random heaving motion with a given energy spectrum which corresponds to a given sea state. A formula is invented by which the instantaneous pitch angle of the wing is determined using the heaving data of the current and past time steps. Simulations are then performed for a biomimetic wing at different heave energy spectra, using an indirect Source-Doublet 3-D-BEM, together with a time stepping algorithm capable to track the random motion of the wing. A nonlinear pressure type Kutta condition is applied at the trailing edge of the wing. With a mollifier-based filtering technique, the 3-D unsteady rollup pattern created by the random motion of the wing is calculated without any simplifying assumptions regarding its geometry. Calculated unsteady forces, moments and useful power, show that the proposed active pitch control always results in thrust producing motions, with significant propulsive power production and considerable beneficial stabilizing action to ship motions. Calculation of the power required to set the pitch angle prove it to be a very small percentage of the useful power and thus making the practical application of the device very tractable.

Biomimetics for NASA Langley Research Center: Year 2000 Report of Findings From a Six-Month Survey

NASA Technical Reports Server (NTRS)

Siochi, Emilie J.; Anders, John B., Jr.; Cox, David E.; Jegley, Dawn C.; Fox, Robert L.; Katzberg, Stephen J.

2002-01-01

This report represents an attempt to see if some of the techniques biological systems use to maximize their efficiency can be applied to the problems NASA faces in aeronautics and space exploration. It includes an internal survey of resources available at NASA Langley Research Center for biomimetics research efforts, an external survey of state of the art in biomimetics covering the Materials, Structures, Aerodynamics, Guidance and Controls areas. The Biomimetics Planning team also included ideas for potential research areas, as well as recommendations on how to implement this new program. This six-month survey was conducted in the second half of 1999.

Biomimetics - using nature as an inspiring model for innovation

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph

2006-01-01

In this presentation, various aspects of the field of biomimetics will be reviewed, examples of inspiring biological models and practical applications will be described, and challenges and potential direction of the field will be discussed.

Strategies in biomimetic surface engineering of nanoparticles for biomedical applications

NASA Astrophysics Data System (ADS)

Gong, Yong-Kuan; Winnik, Françoise M.

2012-01-01

Engineered nanoparticles (NPs) play an increasingly important role in biomedical sciences and in nanomedicine. Yet, in spite of significant advances, it remains difficult to construct drug-loaded NPs with precisely defined therapeutic effects, in terms of release time and spatial targeting. The body is a highly complex system that imposes multiple physiological and cellular barriers to foreign objects. Upon injection in the blood stream or following oral administation, NPs have to bypass numerous barriers prior to reaching their intended target. A particularly successful design strategy consists in masking the NP to the biological environment by covering it with an outer surface mimicking the composition and functionality of the cell's external membrane. This review describes this biomimetic approach. First, we outline key features of the composition and function of the cell membrane. Then, we present recent developments in the fabrication of molecules that mimic biomolecules present on the cell membrane, such as proteins, peptides, and carbohydrates. We present effective strategies to link such bioactive molecules to the NPs surface and we highlight the power of this approach by presenting some exciting examples of biomimetically engineered NPs useful for multimodal diagnostics and for target-specific drug/gene delivery applications. Finally, critical directions for future research and applications of biomimetic NPs are suggested to the readers.

Principles of Biomimetic Vascular Network Design Applied to a Tissue-Engineered Liver Scaffold

PubMed Central

Hoganson, David M.; Pryor, Howard I.; Spool, Ira D.; Burns, Owen H.; Gilmore, J. Randall

2010-01-01

Branched vascular networks are a central component of scaffold architecture for solid organ tissue engineering. In this work, seven biomimetic principles were established as the major guiding technical design considerations of a branched vascular network for a tissue-engineered scaffold. These biomimetic design principles were applied to a branched radial architecture to develop a liver-specific vascular network. Iterative design changes and computational fluid dynamic analysis were used to optimize the network before mold manufacturing. The vascular network mold was created using a new mold technique that achieves a 1:1 aspect ratio for all channels. In vitro blood flow testing confirmed the physiologic hemodynamics of the network as predicted by computational fluid dynamic analysis. These results indicate that this biomimetic liver vascular network design will provide a foundation for developing complex vascular networks for solid organ tissue engineering that achieve physiologic blood flow. PMID:20001254

Principles of biomimetic vascular network design applied to a tissue-engineered liver scaffold.

PubMed

Hoganson, David M; Pryor, Howard I; Spool, Ira D; Burns, Owen H; Gilmore, J Randall; Vacanti, Joseph P

2010-05-01

Branched vascular networks are a central component of scaffold architecture for solid organ tissue engineering. In this work, seven biomimetic principles were established as the major guiding technical design considerations of a branched vascular network for a tissue-engineered scaffold. These biomimetic design principles were applied to a branched radial architecture to develop a liver-specific vascular network. Iterative design changes and computational fluid dynamic analysis were used to optimize the network before mold manufacturing. The vascular network mold was created using a new mold technique that achieves a 1:1 aspect ratio for all channels. In vitro blood flow testing confirmed the physiologic hemodynamics of the network as predicted by computational fluid dynamic analysis. These results indicate that this biomimetic liver vascular network design will provide a foundation for developing complex vascular networks for solid organ tissue engineering that achieve physiologic blood flow.

Tunable denture adhesives using biomimetic principles for enhanced tissue adhesion in moist environments.

PubMed

Gill, Simrone K; Roohpour, Nima; Topham, Paul D; Tighe, Brian J

2017-11-01

Nature provides many interesting examples of adhesive strategies. Of particular note, the protein glue secreted by marine mussels delivers high adhesion in wet and dynamic environments owing to existence of catechol moieties. As such, this study focuses on denture fixatives, where a non-zinc-containing commercial-based formulation has been judiciously modified by a biomimetic catechol-inspired polymer, poly(3,4-dihydroxystyrene/styrene-alt-maleic acid) in a quest to modulate adhesive performance. In vitro studies, in a lap-shear configuration, revealed that the catechol-modified components were able to enhance adhesion to both the denture base and hydrated, functional oral tissue mimic, with the resulting mode of failure prominently being adhesive rather than cohesive. These characteristics are desirable in prosthodontic fixative applications, for which temporary adhesion must be maintained, with ultimately an adhesive failure from the mucosal tissue surface preferred. These insights provide an experimental platform in the design of future biomimetic adhesive systems. Mussel adhesive proteins have proven to be promising biomimetic adhesive candidates for soft tissues and here for the first time we have adapted marine adhesive technology into a denture fixative application. Importantly, we have incorporated a soft tissue mimic in our in vitro adhesion technique that more closely resembles the oral mucosa than previously studied substrates. The novel biomimetic-modified adhesives showed the ability to score the highest adhesive bonding out of all the formulations included in this study, across all moisture levels. This paper will be of major interest to the Acta Biomaterialia readership since the study has illustrated the potential of biomimetic principles in the design of effective prosthodontic tissue adhesives in a series of purpose-designed in vitro experiments in the context of the challenging features of the oral environment. Copyright © 2017 Acta Materialia

Effect of distribution of striated laser hardening tracks on dry sliding wear resistance of biomimetic surface

NASA Astrophysics Data System (ADS)

Su, Wei; Zhou, Ti; Zhang, Peng; Zhou, Hong; Li, Hui

2018-01-01

Some biological surfaces were proved to have excellent anti-wear performance. Being inspired, Nd:YAG pulsed laser was used to create striated biomimetic laser hardening tracks on medium carbon steel samples. Dry sliding wear tests biomimetic samples were performed to investigate specific influence of distribution of laser hardening tracks on sliding wear resistance of biomimetic samples. After comparing wear weight loss of biomimetic samples, quenched sample and untreated sample, it can be suggested that the sample covered with dense laser tracks (3.5 mm spacing) has lower wear weight loss than the one covered with sparse laser tracks (4.5 mm spacing); samples distributed with only dense laser tracks or sparse laser tracks (even distribution) were proved to have better wear resistance than samples distributed with both dense and sparse tracks (uneven distribution). Wear mechanisms indicate that laser track and exposed substrate of biomimetic sample can be regarded as hard zone and soft zone respectively. Inconsecutive striated hard regions, on the one hand, can disperse load into small branches, on the other hand, will hinder sliding abrasives during wear. Soft regions with small range are beneficial in consuming mechanical energy and storing lubricative oxides, however, soft zone with large width (>0.5 mm) will be harmful to abrasion resistance of biomimetic sample because damages and material loss are more obvious on surface of soft phase. As for the reason why samples with even distributed bionic laser tracks have better wear resistance, it can be explained by the fact that even distributed laser hardening tracks can inhibit severe worn of local regions, thus sliding process can be more stable and wear extent can be alleviated as well.

Functional biomimetic analogs help remineralize apatite-depleted demineralized resin-infiltrated dentin via a bottom-up approach

PubMed Central

Kim, Jongryul; Arola, Dwayne D.; Gu, Lisha; Kim, Young Kyung; Mai, Sui; Liu, Yan; Pashley, David H.; Tay, Franklin R.

2010-01-01

Natural biominerals are formed through metastable amorphous precursor phases via a bottom-up, nanoparticle-mediated mineralization mechanism. Using an acid-etched human dentin model to create a layer of completely-demineralized collagen matrix, a bio-inspired mineralization scheme has been developed based on the use of dual biomimetic analogs. These analogs help to sequester fluidic amorphous calcium phosphate nanoprecursors and function as templates for guiding homogeneous apatite nucleation within the collagen fibrils. By adopting this scheme for remineralizing adhesive resin-bonded, completely-demineralized dentin, we have been able to redeposit intrafibrillar and extrafibrillar apatites in completely-demineralized collagen matrices that are imperfectly infiltrated by resins. This study utilizes a spectrum of completely- and partially-demineralized dentin collagen matrices to further validate the necessity for using a biomimetic analog-containing medium for remineralizing resin-infiltrated partially-demineralized collagen matrices in which remnant seed crystallites are present. In control specimens in which biomimetic analogs are absent from the remineralization medium, remineralization could only be seen in partially-demineralized collagen matrices probably by epitaxial growth via a top-down crystallization approach. Conversely, in the presence of biomimetic analogs in the remineralization medium, intrafibrillar remineralization of completely-demineralized collagen matrices via a bottom-up crystallization mechanism can additionally be identified. The latter is characterized by the transition of intrafibrillar minerals from an inchoate state of continuously-braided microfibrillar electron-dense amorphous strands to discrete nanocrystals, and ultimately into larger crystalline platelets within the collagen fibrils. Biomimetic remineralization via dual biomimetic analogs has the potential to be translated into a functional delivery system for salvaging failing

Functional biomimetic analogs help remineralize apatite-depleted demineralized resin-infiltrated dentin via a bottom-up approach.

PubMed

Kim, Jongryul; Arola, Dwayne D; Gu, Lisha; Kim, Young Kyung; Mai, Sui; Liu, Yan; Pashley, David H; Tay, Franklin R

2010-07-01

Natural biominerals are formed through metastable amorphous precursor phases via a bottom-up, nanoparticle-mediated mineralization mechanism. Using an acid-etched human dentin model to create a layer of completely demineralized collagen matrix, a bio-inspired mineralization scheme has been developed based on the use of dual biomimetic analogs. These analogs help to sequester fluidic amorphous calcium phosphate nanoprecursors and function as templates for guiding homogeneous apatite nucleation within the collagen fibrils. By adopting this scheme for remineralizing adhesive resin-bonded, completely demineralized dentin, we have been able to redeposit intrafibrillar and extrafibrillar apatites in completely demineralized collagen matrices that are imperfectly infiltrated by resins. This study utilizes a spectrum of completely and partially demineralized dentin collagen matrices to further validate the necessity for using a biomimetic analog-containing medium for remineralizing resin-infiltrated partially demineralized collagen matrices in which remnant seed crystallites are present. In control specimens in which biomimetic analogs are absent from the remineralization medium, remineralization could only be seen in partially demineralized collagen matrices, probably by epitaxial growth via a top-down crystallization approach. Conversely, in the presence of biomimetic analogs in the remineralization medium, intrafibrillar remineralization of completely demineralized collagen matrices via a bottom-up crystallization mechanism can additionally be identified. The latter is characterized by the transition of intrafibrillar minerals from an inchoate state of continuously braided microfibrillar electron-dense amorphous strands to discrete nanocrystals, and ultimately into larger crystalline platelets within the collagen fibrils. Biomimetic remineralization via dual biomimetic analogs has the potential to be translated into a functional delivery system for salvaging failing

Electroactive polymer and shape memory alloy actuators in biomimetics and humanoids

NASA Astrophysics Data System (ADS)

Tadesse, Yonas

2013-04-01

There is a strong need to replicate natural muscles with artificial materials as the structure and function of natural muscle is optimum for articulation. Particularly, the cylindrical shape of natural muscle fiber and its interconnected structure promote the critical investigation of artificial muscles geometry and implementation in the design phase of certain platforms. Biomimetic robots and Humanoid Robot heads with Facial Expressions (HRwFE) are some of the typical platforms that can be used to study the geometrical effects of artificial muscles. It has been shown that electroactive polymer and shape memory alloy artificial muscles and their composites are some of the candidate materials that may replicate natural muscles and showed great promise for biomimetics and humanoid robots. The application of these materials to these systems reveals the challenges and associated technologies that need to be developed in parallel. This paper will focus on the computer aided design (CAD) models of conductive polymer and shape memory alloys in various biomimetic systems and Humanoid Robot with Facial Expressions (HRwFE). The design of these systems will be presented in a comparative manner primarily focusing on three critical parameters: the stress, the strain and the geometry of the artificial muscle.

Biomimetic particles for isolation and reconstitution of receptor function.

PubMed

Moura, Sérgio P; Carmona-Ribeiro, Ana M

2006-01-01

Biomimetic particles supporting lipid bilayers are becoming increasingly important to isolate and reconstitute protein function. Cholera toxin (CT) from Vibrio cholerae, an 87-kDa AB5 hexameric protein, and its receptor, the monosialoganglioside GM1, a cell membrane glycolipid, self-assembled on phosphatidylcholine (PC) bilayer-covered silica particles at 1 CT/5 GM1 molar ratio in perfect agreement with literature. This receptor-ligand recognition represented a proof-of-concept that receptors in general can be isolated and their function reconstituted using biomimetic particles, i.e., bilayer-covered silica. After incubation of colloidal silica with small unilamellar PC vesicles in saline solution, pH 7.4, PC adsorption isotherms on silica from inorganic phosphorus analysis showed a high PC affinity for silica with maximal PC adsorption at bilayer deposition. At 0.3 mM PC, fluorescence of pyrene-labeled GM(1) showed that GM(1) incorporation in biomimetic particles increased as a function of particles concentration. At 1 mg/mL silica, receptor incorporation increased to a maximum of 40% at 0.2-0.3 mM PC and then decreased as a function of PC concentration. At 5 microM GM(1), 0.3 mM PC, and 1 mg/mL silica, CT binding increased as a function of CT concentration with a plateau at 2 mg bound CT/m2 silica, which corresponded to the 5 GM(1)/1 CT molar proportion and showed successful reconstitution of receptor-ligand interaction.

A water-forming NADH oxidase from Lactobacillus pentosus suitable for the regeneration of synthetic biomimetic cofactors

PubMed Central

Nowak, Claudia; Beer, Barbara; Pick, André; Roth, Teresa; Lommes, Petra; Sieber, Volker

2015-01-01

The cell-free biocatalytic production of fine chemicals by oxidoreductases has continuously grown over the past years. Since especially dehydrogenases depend on the stoichiometric use of nicotinamide pyridine cofactors, an integrated efficient recycling system is crucial to allow process operation under economic conditions. Lately, the variety of cofactors for biocatalysis was broadened by the utilization of totally synthetic and cheap biomimetics. Though, to date the regeneration has been limited to chemical or electrochemical methods. Here, we report an enzymatic recycling by the flavoprotein NADH-oxidase from Lactobacillus pentosus (LpNox). Since this enzyme has not been described before, we first characterized it in regard to its optimal reaction parameters. We found that the heterologously overexpressed enzyme only contained 13% FAD. In vitro loading of the enzyme with FAD, resulted in a higher specific activity towards its natural cofactor NADH as well as different nicotinamide derived biomimetics. Apart from the enzymatic recycling, which gives water as a by-product by transferring four electrons onto oxygen, unbound FAD can also catalyze the oxidation of biomimetic cofactors. Here a two electron process takes place yielding H2O2 instead. The enzymatic and chemical recycling was compared in regard to reaction kinetics for the natural and biomimetic cofactors. With LpNox and FAD, two recycling strategies for biomimetic cofactors are described with either water or hydrogen peroxide as by-product. PMID:26441891

Experimental parametric study of a biomimetic fish robot actuated by piezoelectric actuators

NASA Astrophysics Data System (ADS)

Wiguna, T.; Park, Hoon C.; Heo, S.; Goo, Nam S.

2007-04-01

This paper presents an experiment and parametric study of a biomimetic fish robot actuated by the Lightweight Piezocomposite Actuator (LIPCA). The biomimetic aspects in this work are the oscillating tail beat motion and shape of caudal fin. Caudal fins that resemble fins of BCF (Body and Caudal Fin) mode fish were made in order to perform parametric study concerning the effect of caudal fin characteristics on thrust production at an operating frequency range. The observed caudal fin characteristics are the shape, stiffness, area, and aspect ratio. It is found that a high aspect ratio caudal fin contributes to high swimming speed. The robotic fish propelled by artificial caudal fins shaped after thunniform-fish and mackerel caudal fins, which have relatively high aspect ratio, produced swimming speed as high as 2.364 cm/s and 2.519 cm/s, respectively, for a 300 V p-p input voltage excited at 0.9 Hz. Thrust performance of the biomimetic fish robot is examined by calculating Strouhal number, Froude number, Reynolds number, and power consumption.

A Laboratory Exercise to Introduce Inorganic Biomimetic Compounds.

ERIC Educational Resources Information Center

Baird, Donald M.

1985-01-01

Biomimetic chemistry is concerned with the synthesis of small, molecular weight molecules which mimic the properties of metal-containing sites within certain biologically significant species. A series of experiments for an advanced undergraduate laboratory is described as a way to introduce this area into the chemistry curriculum. (JN)

Biomimetic approaches to modulate cellular adhesion in biomaterials: A review.

PubMed

Rahmany, Maria B; Van Dyke, Mark

2013-03-01

Natural extracellular matrix (ECM) proteins possess critical biological characteristics that provide a platform for cellular adhesion and activation of highly regulated signaling pathways. However, ECM-based biomaterials can have several limitations, including poor mechanical properties and risk of immunogenicity. Synthetic biomaterials alleviate the risks associated with natural biomaterials but often lack the robust biological activity necessary to direct cell function beyond initial adhesion. A thorough understanding of receptor-mediated cellular adhesion to the ECM and subsequent signaling activation has facilitated development of techniques that functionalize inert biomaterials to provide a biologically active surface. Here we review a range of approaches used to modify biomaterial surfaces for optimal receptor-mediated cell interactions, as well as provide insights into specific mechanisms of downstream signaling activation. In addition to a brief overview of integrin receptor-mediated cell function, so-called "biomimetic" techniques reviewed here include (i) surface modification of biomaterials with bioadhesive ECM macromolecules or specific binding motifs, (ii) nanoscale patterning of the materials and (iii) the use of "natural-like" biomaterials. Copyright © 2012 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Growth of aragonite calcium carbonate nanorods in the biomimetic anodic aluminum oxide template

NASA Astrophysics Data System (ADS)

Lee, Inho; Han, Haksoo; Lee, Sang-Yup

2010-04-01

In this study, a biomimetic template was prepared and applied for growing calcium carbonate (CaCO 3) nanorods whose shape and polymorphism were controlled. A biomimetic template was prepared by adsorbing catalytic dipeptides into the pores of an anodic aluminum oxide (AAO) membrane. Using this peptide-adsorbed template, mineralization and aggregation of CaCO 3 was carried out to form large nanorods in the pores. The nanorods were aragonite and had a structure similar to nanoneedle assembly. This aragonite nanorod formation was driven by both the AAO template and catalytic function of dipeptides. The AAO membrane pores promoted generation of aragonite polymorph and guided nanorod formation by guiding the nanorod growth. The catalytic dipeptides promoted the aggregation and further dehydration of calcium species to form large nanorods. Functions of the AAO template and catalytic dipeptides were verified through several control experiments. This biomimetic approach makes possible the production of functional inorganic materials with controlled shapes and crystalline structures.

Lactoferrin Adsorbed onto Biomimetic Hydroxyapatite Nanocrystals Controlling - In Vivo - the Helicobacter pylori Infection

PubMed Central

Fulgione, Andrea; Nocerino, Nunzia; Iannaccone, Marco; Roperto, Sante; Capuano, Federico; Roveri, Norberto; Lelli, Marco; Crasto, Antonio; Calogero, Armando; Pilloni, Argenia Paola; Capparelli, Rosanna

2016-01-01

Background The resistance of Helicobacter pylori to the antibiotic therapy poses the problem to discover new therapeutic approaches. Recently it has been stated that antibacterial, immunomodulatory, and antioxidant properties of lactoferrin are increased when this protein is surface-linked to biomimetic hydroxyapatite nanocrystals. Objective Based on these knowledge, the aim of the study was to investigate the efficacy of lactoferrin delivered by biomimetic hydroxyapatite nanoparticles with cell free supernatant from probiotic Lactobacillus paracasei as an alternative therapy against Helicobacter pylori infection. Methods Antibacterial and antinflammatory properties, humoral antibody induction, histopathological analysis and absence of side effects were evaluated in both in vitro and in vivo studies. Results The tests carried out have been demonstrated better performance of lactoferrin delivered by biomimetic hydroxyapatite nanoparticles combined with cell free supernatant from probiotic Lactobacillus paracasei compared to both lactoferrin and probiotic alone or pooled. Conclusion These findings indicate the effectiveness and safety of our proposed therapy as alternative treatment for Helicobacter pylori infection. PMID:27384186

Molecular modelling for the design of chimaeric biomimetic dye-ligands and their interaction with bovine heart mitochondrial malate dehydrogenase.

PubMed Central

Labrou, N E; Eliopoulos, E; Clonis, Y D

1996-01-01

Molecular modelling and kinetic inhibition studies, as well as KD determinations by both difference-spectra and enzyme-inactivation studies, were employed to assess the ability of purpose-designed chimaeric biomimetic dyes (BM dyes) to act as affinity ligands for bovine heart L-malate dehydrogenase (MDH). Each BM dye was composed of two enzyme-recognition moieties. The terminal biomimetic moiety bore a carboxyl or a keto acid structure linked to the triazine ring, thus mimicking the substrate of MDH. The chromophore anthraquinone moiety remained unchanged and the same as that of the parent dye Vilmafix Blue A-R (VBAR), recognizing the nucleotide-binding site of MDH. The monochlorotriazine BM dyes did not inactivate MDH but competitively inhibited inactivation by the parent dichlorotriazine dye VBAR. Dye binding to MDH was accompanied by a characteristic spectral change in the range 500-850 nm. This phenomenon was reversed after titration with increasing amounts of NADH. When compared with VBAR, Cibacron Blue 3GA and two control non-biomimetic anthraquinone dyes, all BM dyes exhibited lower KD values and therefore higher affinity for MDH. The enzyme bound preferably to BM ligands substituted with a biomimetic aromatic moiety bearing an alpha-keto acid group and an amide linkage, rather than a monocarboxyl group. Thus the biomimetic dye bearing p-aminobenzyloxanilic acid as its terminal biomimetic moiety (BM5) exhibited the highest affinity (KD 1.3 microM, which corresponded to a 219-fold decrease over the KD of a control dye). BM5 displayed competitive inhibition with respect to both NADH (Ki 2.7 microM) and oxaloacetate (Ki 9.6 microM). A combination of molecular modelling and experimental studies has led to certain conclusions. The positioning of the dye in the enzyme is primarily achieved by the recognition and positioning of the nucleotide-pseudomimetic anthraquinone moiety. The hydrophobic groups of the dye provide the driving force for positioning of the

Biomimetic syntheses of phenols from polyketones.

PubMed

Evans, G E; Garson, M J; Griffin, D A; Leeper, F J; Stauton, J

1978-01-01

As a result of speculation that many enzymes control polyketone cyclization in vivo by converting a key carbonyl group to a cis-enol ether derivative, we describe two novel biomimetic cyclizations. The first involves condensation of two C6 units derived from triacetic lactone to form an arylpyrone related to aloenin. In the second a naphthapyrone of the rubrofusarin type is formed by condensation of an orsellinic acid derivative with the ether of triacetic lactone.

Templated biomimetic multifunctional coatings

NASA Astrophysics Data System (ADS)

Sun, Chih-Hung; Gonzalez, Adriel; Linn, Nicholas C.; Jiang, Peng; Jiang, Bin

2008-02-01

We report a bioinspired templating technique for fabricating multifunctional optical coatings that mimic both unique functionalities of antireflective moth eyes and superhydrophobic cicada wings. Subwavelength-structured fluoropolymer nipple arrays are created by a soft-lithography-like process. The utilization of fluoropolymers simultaneously enhances the antireflective performance and the hydrophobicity of the replicated films. The specular reflectivity matches the optical simulation using a thin-film multilayer model. The dependence of the size and the crystalline ordering of the replicated nipples on the resulting antireflective properties have also been investigated by experiment and modeling. These biomimetic materials may find important technological application in self-cleaning antireflection coatings.

Synthetic biology and biomimetic chemistry as converging technologies fostering a new generation of smart biosensors.

PubMed

Scognamiglio, Viviana; Antonacci, Amina; Lambreva, Maya D; Litescu, Simona C; Rea, Giuseppina

2015-12-15

Biosensors are powerful tunable systems able to switch between an ON/OFF status in response to an external stimulus. This extraordinary property could be engineered by adopting synthetic biology or biomimetic chemistry to obtain tailor-made biosensors having the desired requirements of robustness, sensitivity and detection range. Recent advances in both disciplines, in fact, allow to re-design the configuration of the sensing elements - either by modifying toggle switches and gene networks, or by producing synthetic entities mimicking key properties of natural molecules. The present review considered the role of synthetic biology in sustaining biosensor technology, reporting examples from the literature and reflecting on the features that make it a useful tool for designing and constructing engineered biological systems for sensing application. Besides, a section dedicated to bioinspired synthetic molecules as powerful tools to enhance biosensor potential is reported, and treated as an extension of the concept of biomimetic chemistry, where organic synthesis is used to generate artificial molecules that mimic natural molecules. Thus, the design of synthetic molecules, such as aptamers, biomimetics, molecular imprinting polymers, peptide nucleic acids, and ribozymes were encompassed as "products" of biomimetic chemistry. Copyright © 2015 Elsevier B.V. All rights reserved.

Calixarenes and Their Biomimetic Applications

PubMed Central

Agrawal, Y. K.; Bhatt, Harshit

2004-01-01

The synthetic models for the structures, spectroscopic properties and catalytic activities of metalloprotein active sites have been reviewed. Calixarenes were used as new biomimetic catalysts because of their advantage of providing preorganiiation of the catalytic group, which can bind the substrate dynamically that results in fast turnover and fast release of the products. Functional and structural models based on calixarenes are presented and in addition importance of molecular recognition and non-covalent interactions e.g. hydrogen bonding and their role in biological systems are discussed with the help of synthetic systems. PMID:18365079

Aloe vera Induced Biomimetic Assemblage of Nucleobase into Nanosized Particles

PubMed Central

Chauhan, Arun; Zubair, Swaleha; Sherwani, Asif; Owais, Mohammad

2012-01-01

Aim Biomimetic nano-assembly formation offers a convenient and bio friendly approach to fabricate complex structures from simple components with sub-nanometer precision. Recently, biomimetic (employing microorganism/plants) synthesis of metal and inorganic materials nano-particles has emerged as a simple and viable strategy. In the present study, we have extended biological synthesis of nano-particles to organic molecules, namely the anticancer agent 5-fluorouracil (5-FU), using Aloe vera leaf extract. Methodology The 5-FU nano- particles synthesized by using Aloe vera leaf extract were characterized by UV, FT-IR and fluorescence spectroscopic techniques. The size and shape of the synthesized nanoparticles were determined by TEM, while crystalline nature of 5-FU particles was established by X-ray diffraction study. The cytotoxic effects of 5-FU nanoparticles were assessed against HT-29 and Caco-2 (human adenocarcinoma colorectal) cell lines. Results Transmission electron microscopy and atomic force microscopic techniques confirmed nano-size of the synthesized particles. Importantly, the nano-assembled 5-FU retained its anticancer action against various cancerous cell lines. Conclusion In the present study, we have explored the potential of biomimetic synthesis of nanoparticles employing organic molecules with the hope that such developments will be helpful to introduce novel nano-particle formulations that will not only be more effective but would also be devoid of nano-particle associated putative toxicity constraints. PMID:22403622

Biomimetic devices functionalized by membrane channel proteins

NASA Astrophysics Data System (ADS)

Schmidt, Jacob

2004-03-01

We are developing a new family of active materials which derive their functional properties from membrane proteins. These materials have two primary components: the proteins and the membranes themselves. I will discuss our recent work directed toward development of a generic platform for a "plug-and-play" philosophy of membrane protein engineering. By creating a stable biomimetic polymer membrane a single molecular monolayer thick, we will enable the exploitation of the function of any membrane protein, from pores and pumps to sensors and energy transducers. Our initial work has centered on the creation, study, and characterization of the biomimetic membranes. We are attempting to make large areas of membrane monolayers using Langmuir-Blodgett film formation as well as through arrays of microfabricated black lipid membrane-type septa. A number of techniques allow the insertion of protein into the membranes. As a benchmark, we have been employing a model system of voltage-gated pore proteins, which have electrically controllable porosities. I will report on the progress of this work, the characterization of the membranes, protein insertion processes, and the yield and functionality of the composite.

Progress on bioinspired, biomimetic, and bioreplication routes to harvest solar energy

NASA Astrophysics Data System (ADS)

Martín-Palma, Raúl J.; Lakhtakia, Akhlesh

2017-06-01

Although humans have long been imitating biological structures to serve their particular purposes, only a few decades ago engineered biomimicry began to be considered a technoscientific discipline with a great problem-solving potential. The three methodologies of engineered biomimicry-viz., bioinspiration, biomimetic, and bioreplication-employ and impact numerous technoscientific fields. For producing fuels and electricity by artificial photosynthesis, both processes and porous surfaces inspired by plants and certain marine animals are under active investigation. Biomimetically textured surfaces on the subwavelength scale have been shown to reduce the reflectance of photovoltaic solar cells over the visible and the near-infrared regimes. Lenticular compound lenses bioreplicated from insect eyes by an industrially scalable technique offer a similar promise.

Effects of PEGylation on biomimetic synthesis of magnetoferritin nanoparticles

NASA Astrophysics Data System (ADS)

Yang, Caiyun; Cao, Changqian; Cai, Yao; Xu, Huangtao; Zhang, Tongwei; Pan, Yongxin

2017-03-01

Recent studies have demonstrated that ferrimagnetic magnetoferritin nanoparticles are a promising novel magnetic nanomaterial in biomedical applications, including biocatalysis, imaging, diagnostics, and tumor therapy. Here we investigated the PEGylation of human H-ferritin (HFn) proteins and the possible influence on biomimetic synthesis of magnetoferritin nanoparticles. The outer surface of HFn proteins was chemically modified with different PEG molecular weights (PEG10K and PEG20K) and different modification ratios (HFn subunit:PEG20K = 1:1, 1:2, 1:4). The PEGylated HFn proteins were used for biomimetic synthesis of ferrimagnetic magnetoferritin nanoparticles. We found that, compared with magnetoferritin using non-PEGylated HFn protein templates, the synthesized magnetoferritin using the PEGylated HFn protein templates possessed larger magnetite cores, higher magnetization and relaxivity values, and improved thermal stability. These results suggest that the PEGylation of H-ferritin may improve the biomineralization of magnetoferritin nanoparticles and enhance their biomedical applications.

Evolutionary algorithm optimization of biological learning parameters in a biomimetic neuroprosthesis

PubMed Central

Dura-Bernal, S.; Neymotin, S. A.; Kerr, C. C.; Sivagnanam, S.; Majumdar, A.; Francis, J. T.; Lytton, W. W.

2017-01-01

Biomimetic simulation permits neuroscientists to better understand the complex neuronal dynamics of the brain. Embedding a biomimetic simulation in a closed-loop neuroprosthesis, which can read and write signals from the brain, will permit applications for amelioration of motor, psychiatric, and memory-related brain disorders. Biomimetic neuroprostheses require real-time adaptation to changes in the external environment, thus constituting an example of a dynamic data-driven application system. As model fidelity increases, so does the number of parameters and the complexity of finding appropriate parameter configurations. Instead of adapting synaptic weights via machine learning, we employed major biological learning methods: spike-timing dependent plasticity and reinforcement learning. We optimized the learning metaparameters using evolutionary algorithms, which were implemented in parallel and which used an island model approach to obtain sufficient speed. We employed these methods to train a cortical spiking model to utilize macaque brain activity, indicating a selected target, to drive a virtual musculoskeletal arm with realistic anatomical and biomechanical properties to reach to that target. The optimized system was able to reproduce macaque data from a comparable experimental motor task. These techniques can be used to efficiently tune the parameters of multiscale systems, linking realistic neuronal dynamics to behavior, and thus providing a useful tool for neuroscience and neuroprosthetics. PMID:29200477

The importance of the biomimetic composites components for recreating the optical properties and molecular composition of intact dental tissues.

NASA Astrophysics Data System (ADS)

Seredin, P. V.; Goloshchapov, D. L.; Gushchin, M. S.; Ippolitov, Y. A.; Prutskij, T.

2017-11-01

The objective of this paper was to investigate whether it is possible to obtain biomimetic materials recreating the luminescent properties and molecular composition of intact dental tissues. Biomimetic materials were produced and their properties compared with native dental tissues. In addition, the overall contribution of the organic and non-organic components in the photoluminescence band was investigated. The results showed that it is possible to develop biomimetic materials with similar molecular composition and optical properties to native dental tissues for the early identification of dental caries.

Imprinting Technology in Electrochemical Biomimetic Sensors

PubMed Central

Frasco, Manuela F.; Truta, Liliana A. A. N. A.; Sales, M. Goreti F.; Moreira, Felismina T. C.

2017-01-01

Biosensors are a promising tool offering the possibility of low cost and fast analytical screening in point-of-care diagnostics and for on-site detection in the field. Most biosensors in routine use ensure their selectivity/specificity by including natural receptors as biorecognition element. These materials are however too expensive and hard to obtain for every biochemical molecule of interest in environmental and clinical practice. Molecularly imprinted polymers have emerged through time as an alternative to natural antibodies in biosensors. In theory, these materials are stable and robust, presenting much higher capacity to resist to harsher conditions of pH, temperature, pressure or organic solvents. In addition, these synthetic materials are much cheaper than their natural counterparts while offering equivalent affinity and sensitivity in the molecular recognition of the target analyte. Imprinting technology and biosensors have met quite recently, relying mostly on electrochemical detection and enabling a direct reading of different analytes, while promoting significant advances in various fields of use. Thus, this review encompasses such developments and describes a general overview for building promising biomimetic materials as biorecognition elements in electrochemical sensors. It includes different molecular imprinting strategies such as the choice of polymer material, imprinting methodology and assembly on the transduction platform. Their interface with the most recent nanostructured supports acting as standard conductive materials within electrochemical biomimetic sensors is pointed out. PMID:28272314

Biomimetic multifunctional surfaces inspired from animals.

PubMed

Han, Zhiwu; Mu, Zhengzhi; Yin, Wei; Li, Wen; Niu, Shichao; Zhang, Junqiu; Ren, Luquan

2016-08-01

Over millions of years, animals have evolved to a higher intelligent level for their environment. A large number of diverse surface structures on their bodies have been formed to adapt to the extremely harsh environment. Just like the structural diversity existed in plants, the same also applies true in animals. Firstly, this article provides an overview and discussion of the most common functional surface structures inspired from animals, such as drag reduction, noise reduction, anti-adhesion, anti-wear, anti-erosion, anti-fog, water capture, and optical surfaces. Then, some typical characteristics of morphologies, structures, and materials of the animal multifunctional surfaces were discussed. The adaptation of these surfaces to environmental conditions was also analyzed. It mainly focuses on the relationship between their surface functions and their surface structural characteristics. Afterwards, the multifunctional mechanisms or principles of these surfaces were discussed. Models of these structures were provided for the development of structure materials and machinery surfaces. At last, fabrication techniques and existing or potential technical applications inspired from biomimetic multifunctional surfaces in animals were also discussed. The application prospects of the biomimetic functional surfaces are very broad, such as civil field of self-cleaning textile fabrics and non-stick pots, ocean field of oil-water separation, sports field of swimming suits, space development field of lens arrays. Copyright © 2016 Elsevier B.V. All rights reserved.

9-Fluorenylmethyl (Fm) Disulfides: Biomimetic Precursors for Persulfides

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

Park, Chung-Min; Johnson, Brett A.; Duan, Jicheng

Protein S-sulfhydration has been recognized as an important post-translational modification that regulates H2S signals. However, the reactivity and biological implications of the products of S-sulfhydration, i.e. persulfides, are still unclear. This is mainly due to the instability of persulfides and difficulty to access these molecules. Under physiological conditions persulfides mainly exist in anionic forms because of their low pKa values. However, current methods do not allow for the direct generation of persulfide anions under biomimetic and non-H2S conditions. Herein we report the development of a functional disulfide, FmSSPy-A (Fm =9-fluorenylmethyl; Py = pyridinyl). This reagent can effectively convert both smallmore » molecule and protein thiols (-SH) to form –S-SFm adducts under mild conditions. It allows for a H2S-free and biomimetic protocol to generate highly reactive persulfides (in their anionic forms). We also demonstrated the high nucleophilicity of persulfides toward a number of thiol-blocking reagents. This method holds promise for further understanding the chemical biology of persulfides and S-sulfhydration.« less

3D Printing of Lotus Root-Like Biomimetic Materials for Cell Delivery and Tissue Regeneration.

PubMed

Feng, Chun; Zhang, Wenjie; Deng, Cuijun; Li, Guanglong; Chang, Jiang; Zhang, Zhiyuan; Jiang, Xinquan; Wu, Chengtie

2017-12-01

Biomimetic materials have drawn more and more attention in recent years. Regeneration of large bone defects is still a major clinical challenge. In addition, vascularization plays an important role in the process of large bone regeneration and microchannel structure can induce endothelial cells to form rudimentary vasculature. In recent years, 3D printing scaffolds are major materials for large bone defect repair. However, these traditional 3D scaffolds have low porosity and nonchannel structure, which impede angiogenesis and osteogenesis. In this study, inspired by the microstructure of natural plant lotus root, biomimetic materials with lotus root-like structures are successfully prepared via a modified 3D printing strategy. Compared with traditional 3D materials, these biomimetic materials can significantly improve in vitro cell attachment and proliferation as well as promote in vivo osteogenesis, indicating potential application for cell delivery and bone regeneration.

Controlling tissue microenvironments: biomimetics, transport phenomena, and reacting systems.

PubMed

Fisher, Robert J; Peattie, Robert A

2007-01-01

The reconstruction of tissues ex vivo and production of cells capable of maintaining a stable performance for extended time periods in sufficient quantity for synthetic or therapeutic purposes are primary objectives of tissue engineering. The ability to characterize and manipulate the cellular microenvironment is critical for successful implementation of such cell-based bioengineered systems. As a result, knowledge of fundamental biomimetics, transport phenomena, and reaction engineering concepts is essential to system design and development. Once the requirements of a specific tissue microenvironment are understood, the biomimetic system specifications can be identified and a design implemented. Utilization of novel membrane systems that are engineered to possess unique transport and reactive features is one successful approach presented here. The limited availability of tissue or cells for these systems dictates the need for microscale reactors. A capstone illustration based on cellular therapy for type 1 diabetes mellitus via encapsulation techniques is presented as a representative example of this approach, to stress the importance of integrated systems.

A small biomimetic quadruped robot driven by multistacked dielectric elastomer actuators

NASA Astrophysics Data System (ADS)

Nguyen, Canh Toan; Phung, Hoa; Dat Nguyen, Tien; Lee, Choonghan; Kim, Uikyum; Lee, Donghyouk; Moon, Hyungpil; Koo, Jachoon; Nam, Jae-do; Ryeol Choi, Hyouk

2014-06-01

A kind of dielectric elastomer (DE) material, called ‘synthetic elastomer’, has been developed based on acrylonitrile butadiene rubber (NBR) to be used as a dielectric elastomer actuator (DEA). By stacking single layers of synthetic elastomer, a linear actuator, called a multistacked actuator, is produced, and used by mechatronic and robotic systems to generate linear motion. In this paper, we demonstrate the application of the multistacked dielectric elastomer actuator in a biomimetic legged robot. A miniature robot driven by a biomimetic actuation system with four 2-DOF (two-degree-of-freedom) legged mechanisms is realized. Based on the experimental results, we evaluate the performance of the proposed robot and validate the feasibility of the multistacked actuator in a locomotion system as a replacement for conventional actuators.

Biomimetic design processes in architecture: morphogenetic and evolutionary computational design.

PubMed

Menges, Achim

2012-03-01

Design computation has profound impact on architectural design methods. This paper explains how computational design enables the development of biomimetic design processes specific to architecture, and how they need to be significantly different from established biomimetic processes in engineering disciplines. The paper first explains the fundamental difference between computer-aided and computational design in architecture, as the understanding of this distinction is of critical importance for the research presented. Thereafter, the conceptual relation and possible transfer of principles from natural morphogenesis to design computation are introduced and the related developments of generative, feature-based, constraint-based, process-based and feedback-based computational design methods are presented. This morphogenetic design research is then related to exploratory evolutionary computation, followed by the presentation of two case studies focusing on the exemplary development of spatial envelope morphologies and urban block morphologies.

Biomimetic Mineralization on a Macroporous Cellulose-Based Matrix for Bone Regeneration

PubMed Central

Petrauskaite, Odeta; Gomes, Pedro de Sousa; Fernandes, Maria Helena; Juodzbalys, Gintaras; Maminskas, Julius

2013-01-01

The aim of this study is to investigate the biomimetic mineralization on a cellulose-based porous matrix with an improved biological profile. The cellulose matrix was precalcified using three methods: (i) cellulose samples were treated with a solution of calcium chloride and diammonium hydrogen phosphate; (ii) the carboxymethylated cellulose matrix was stored in a saturated calcium hydroxide solution; (iii) the cellulose matrix was mixed with a calcium silicate solution in order to introduce silanol groups and to combine them with calcium ions. All the methods resulted in a mineralization of the cellulose surfaces after immersion in a simulated body fluid solution. Over a period of 14 days, the matrix was completely covered with hydroxyapatite crystals. Hydroxyapatite formation depended on functional groups on the matrix surface as well as on the precalcification method. The largest hydroxyapatite crystals were obtained on the carboxymethylated cellulose matrix treated with calcium hydroxide solution. The porous cellulose matrix was not cytotoxic, allowing the adhesion and proliferation of human osteoblastic cells. Comparatively, improved cell adhesion and growth rate were achieved on the mineralized cellulose matrices. PMID:24163816

X-Ray absorption spectroscopy quantitative analysis of biomimetic copper(II) complexes with tridentate nitrogen ligands mimicking the tris(imidazole) array of protein centres.

PubMed

Borghi, Elena; Casella, Luigi

2010-02-21

In this study copper(ii) complexes with the tridentate nitrogen ligand bis[2-(1-methylbenzimidazol-2-yl)ethyl]amine (2-BB) are considered as model compounds for the Cu-tris(imidazole) array found in several copper proteins. 2-BB chelates copper(ii) forming two six-membered rings and the complexes contain methanol, nitrite, azide and water as ancillary ligands; both the coordination numbers and stereochemistries differ in these complexes. Their key structural features were investigated by using full multiple-scattering theoretical analysis of the copper K-edge X-ray absorption spectrum with the MXAN code. We showed that using cluster sizes large enough to include all atoms of the ligand, the analysis of the XANES region can give both a structural model of the metal centre and map the structure of the 2-BB complexes. Complex [Cu(2-BB)(N(3))](+) provided a critical test through the comparison of the XANES simulation results with crystallographic data, thus permitting the extension of the method to the complex [Cu(2-BB)(H(2)O)(n)](+) (n = 1 or 2), for which crystallographic data are not available but is expected to bear a five-coordinated Cu(3N)(2O) core (n = 2). The structural data of [Cu(2-BB)(MeOH)(ClO(4))](+) and [Cu(2-BB)(NO(2))](+), both with a Cu(3N)(2O) core but with a different stereochemistry, were used as the starting parameters for two independent simulations of the XANES region of the [Cu(2-BB)(H(2)O)(2)](+) cation. The two structural models generated by simulation converge towards a structure for the aqua-cation with a lower coordination number. New calculations, where four-coordinated Cu(3N)(O) cores were considered as the starting structures, validated that the structure of the aqua-complex in the powder state has a copper(ii) centre with a four-coordinated Cu(3N)(O) core and a molecular formula [Cu(2-BB)(H(2)O)](ClO(4)).(H(2)O). A water solvation molecule, presumed to be disordered from the simulations with the two Cu(3N)(2O) cores, is present. The

Biomimetics and Tubercles on Flippers for Hydrodynamic Flow Control

NASA Astrophysics Data System (ADS)

Fish, Frank E.

2011-11-01

The biomimetic approach seeks to incorporate designs based on biological organisms into engineered technologies. Biomimetics can be used to engineer machines that emulate the performance of organisms, particularly in instances where the organism's performance exceeds current mechanical technology or provides new directions to solve existing problems. The ability to control the flow of water around the body dictates the performance of marine mammals in the aquatic environment. Morphological specializations of marine mammals afford mechanisms for passive flow control. Aside from the design of the body, which minimizes drag, the morphology of the appendages provide hydrodynamic advantages with respect to drag, lift, thrust, and stall. Of particular interest are the pectoral flippers of the humpback whale (Megaptera novaeangliae). These flippers act as wing-like structures to provide hydrodynamic lift for maneuvering. The use of any such wing-like structure in making small radius turns to enhance both agility and maneuverability is constrained by performance associated with stall. Delay of stall can be accomplished passively by modification of the flipper leading edge. The design of the flippers includes prominent leading edge bumps or tubercles. Such a design is exhibited by the leading edge tubercles on the flippers of humpback whales. These novel morphological structures induce a spanwise flow field of separated vortices alternating with regions of accelerated flow. The coupled flow regions maintain areas of attached flow and delay stall to high angles of attack. The morphological features of humpback whales for flow control can be utilized in the biomimetic design of engineered structures and commercial products for increased hydrodynamic performance. Nature retains a store of untouched knowledge, which would be beneficial in advancing technology.

3D Printing of Lotus Root‐Like Biomimetic Materials for Cell Delivery and Tissue Regeneration

PubMed Central

Feng, Chun; Zhang, Wenjie; Deng, Cuijun; Li, Guanglong; Chang, Jiang; Zhang, Zhiyuan

2017-01-01

Abstract Biomimetic materials have drawn more and more attention in recent years. Regeneration of large bone defects is still a major clinical challenge. In addition, vascularization plays an important role in the process of large bone regeneration and microchannel structure can induce endothelial cells to form rudimentary vasculature. In recent years, 3D printing scaffolds are major materials for large bone defect repair. However, these traditional 3D scaffolds have low porosity and nonchannel structure, which impede angiogenesis and osteogenesis. In this study, inspired by the microstructure of natural plant lotus root, biomimetic materials with lotus root‐like structures are successfully prepared via a modified 3D printing strategy. Compared with traditional 3D materials, these biomimetic materials can significantly improve in vitro cell attachment and proliferation as well as promote in vivo osteogenesis, indicating potential application for cell delivery and bone regeneration. PMID:29270348

A review of selected pumping systems in nature and engineering--potential biomimetic concepts for improving displacement pumps and pulsation damping.

PubMed

Bach, D; Schmich, F; Masselter, T; Speck, T

2015-09-03

The active transport of fluids by pumps plays an essential role in engineering and biology. Due to increasing energy costs and environmental issues, topics like noise reduction, increase of efficiency and enhanced robustness are of high importance in the development of pumps in engineering. The study compares pumps in biology and engineering and assesses biomimetic potentials for improving man-made pumping systems. To this aim, examples of common challenges, applications and current biomimetic research for state-of-the art pumps are presented. The biomimetic research is helped by the similar configuration of many positive displacement pumping systems in biology and engineering. In contrast, the configuration and underlying pumping principles for fluid dynamic pumps (FDPs) differ to a greater extent in biology and engineering. However, progress has been made for positive displacement as well as for FDPs by developing biomimetic devices with artificial muscles and cilia that improve energetic efficiency and fail-safe operation or reduce noise. The circulatory system of vertebrates holds a high biomimetic potential for the damping of pressure pulsations, a common challenge in engineering. Damping of blood pressure pulsation results from a nonlinear viscoelastic behavior of the artery walls which represent a complex composite material. The transfer of the underlying functional principle could lead to an improvement of existing technical solutions and be used to develop novel biomimetic damping solutions. To enhance efficiency or thrust of man-made fluid transportation systems, research on jet propulsion in biology has shown that a pulsed jet can be tuned to either maximize thrust or efficiency. The underlying principle has already been transferred into biomimetic applications in open channel water systems. Overall there is a high potential to learn from nature in order to improve pumping systems for challenges like the reduction of pressure pulsations, increase of jet

Biomimetic TiO2 formation from interfacial sol-gel chemistry leading to new photocatalysts

NASA Astrophysics Data System (ADS)

Jaffer Al-Timimi, Iman A.; Onwukwe, Uche K.; Worsley, Myles P.; Sermon, Paul A.

2016-09-01

The surfaces of Portobello mushroom spores (PMS) have been used to produce Au and Ag nanoparticles, which are held thereon. They have then been overcoated with TiOx. These adsorbed more methyl orange (MO) pollutant from water than commercial P25 TiO2. After calcination they form biomimetic TiO2 (PMS) and removal of the biotemplate, they catalyse faster rates of MO from water (molecules/mg/s) than P25 anataserutile. Other biotemplates are now anticipated that will yield biomimetic photocatalysts with higher turnover number (s-1) removal of endocrine disrupters from water.

Layer-by-Layer Assembled Nanotubes as Biomimetic Nanoreactors for Calcium Carbonate Deposition.

PubMed

He, Qiang; Möhwald, Helmuth; Li, Junbai

2009-09-17

Enzyme-loaded magnetic polyelectrolyte multilayer nanotubes prepared by layer-by-layer assembly combined with the porous template could be used as biomimetic nanoreactors. It is demonstrated that calcium carbonate can be biomimetically synthesized inside the cavities of the polyelectrolyte nanotubes by the catalysis of urease, and the size of the calcium carbonate precipitates was controlled by the cavity dimensions. The metastable structure of the calcium carbonate precipitates inside the nanotubes was protected by the outer shell of the polyelectrolyte multilayers. These features may allow polyelectrolyte nanotubes to be applied in the fields of nanomaterials synthesis, controlled release, and drug delivery. Copyright © 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Recent Progress in Biomimetic Additive Manufacturing Technology: From Materials to Functional Structures.

PubMed

Yang, Yang; Song, Xuan; Li, Xiangjia; Chen, Zeyu; Zhou, Chi; Zhou, Qifa; Chen, Yong

2018-06-19

Nature has developed high-performance materials and structures over millions of years of evolution and provides valuable sources of inspiration for the design of next-generation structural materials, given the variety of excellent mechanical, hydrodynamic, optical, and electrical properties. Biomimicry, by learning from nature's concepts and design principles, is driving a paradigm shift in modern materials science and technology. However, the complicated structural architectures in nature far exceed the capability of traditional design and fabrication technologies, which hinders the progress of biomimetic study and its usage in engineering systems. Additive manufacturing (three-dimensional (3D) printing) has created new opportunities for manipulating and mimicking the intrinsically multiscale, multimaterial, and multifunctional structures in nature. Here, an overview of recent developments in 3D printing of biomimetic reinforced mechanics, shape changing, and hydrodynamic structures, as well as optical and electrical devices is provided. The inspirations are from various creatures such as nacre, lobster claw, pine cone, flowers, octopus, butterfly wing, fly eye, etc., and various 3D-printing technologies are discussed. Future opportunities for the development of biomimetic 3D-printing technology to fabricate next-generation functional materials and structures in mechanical, electrical, optical, and biomedical engineering are also outlined. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Synthetic Hydroxyapatite as a Biomimetic Oral Care Agent.

PubMed

Enax, Joachim; Epple, Matthias

Human tooth enamel consists mostly of minerals, primarily hydroxyapatite, Ca10(PO4)6(OH)2, and thus synthetic hydroxyapatite can be used as a biomimetic oral care agent. This review describes the synthesis and characterization of hydroxyapatite from a chemist's perspective and provides an overview of its current use in oral care, with a focus on dentin hypersensitivity, caries, biofilm management, erosion, and enamel lesions. Reviews and original research papers published in English and German were included. The efficiency of synthetic hydroxyapatite in occluding open dentin tubules, resulting in a protection for sensitive teeth, has been well documented in a number of clinical studies. The first corresponding studies on caries, biofilm management and erosion have provided evidence for a positive effect of hydroxyapatite either as a main or synergistic agent in oral care products. However, more in situ and in vivo studies are needed due to the complexity of the oral milieu and to further clarify existing results. Due to its biocompatibility and similarity to biologically formed hydroxyapatite in natural tooth enamel, synthetic hydroxyapatite is a promising biomimetic oral care ingredient that may extend the scope of preventive dentistry.

Biomimetic Photonic Crystals based on Diatom Algae Frustules

NASA Astrophysics Data System (ADS)

Mishler, Jonathan; Alverson, Andrew; Herzog, Joseph

2015-03-01

Diatom algae are unicellular, photosynthetic microorganisms with a unique external shell known as a frustule. Frustules, which are composed of amorphous silica, exhibit a unique periodic nano-patterning, distinguishing diatoms from other types of phytoplankton. Diatoms have been studied for their distinctive optical properties due to their resemblance of photonic crystals. In this regard, diatoms are not only considered for their applications as photonic crystals, but also for their use as biomimetic templates for artificially fabricated photonic crystals. Through the examination and measurement of the physical characteristics of many scanning electron microscope (SEM) images of diatom frustules, a biomimetic photonic crystal derived from diatom frustules can be recreated and modeled with the finite element method. In this approach, the average geometries of the diatom frustules are used to recreate a 2-dimensional photonic crystal, after which the electric field distribution and optical transmission through the photonic crystal are both measured. The optical transmission is then compared to the transmission spectra of a regular hexagonal photonic crystal, revealing the effects of diatom geometry on their optical properties. Finally, the dimensions of the photonic crystal are parametrically swept, allowing for further control over the transmission of light through the photonic crystal.

Self-assembled biomimetic antireflection coatings

NASA Astrophysics Data System (ADS)

Linn, Nicholas C.; Sun, Chih-Hung; Jiang, Peng; Jiang, Bin

2007-09-01

The authors report a simple self-assembly technique for fabricating antireflection coatings that mimic antireflective moth eyes. Wafer-scale, nonclose-packed colloidal crystals with remarkable large hexagonal domains are created by a spin-coating technology. The resulting polymer-embedded colloidal crystals exhibit highly ordered surface modulation and can be used directly as templates to cast poly(dimethylsiloxane) (PDMS) molds. Moth-eye antireflection coatings with adjustable reflectivity can then be molded against the PDMS master. The specular reflection of replicated nipple arrays matches the theoretical prediction using a thin-film multilayer model. These biomimetic films may find important technological application in optical coatings and solar cells.

Biomimetics: its practice and theory.

PubMed

Vincent, Julian F V; Bogatyreva, Olga A; Bogatyrev, Nikolaj R; Bowyer, Adrian; Pahl, Anja-Karina

2006-08-22

Biomimetics, a name coined by Otto Schmitt in the 1950s for the transfer of ideas and analogues from biology to technology, has produced some significant and successful devices and concepts in the past 50 years, but is still empirical. We show that TRIZ, the Russian system of problem solving, can be adapted to illuminate and manipulate this process of transfer. Analysis using TRIZ shows that there is only 12% similarity between biology and technology in the principles which solutions to problems illustrate, and while technology solves problems largely by manipulating usage of energy, biology uses information and structure, two factors largely ignored by technology.

Biomimetics: its practice and theory

PubMed Central

Vincent, Julian F.V; Bogatyreva, Olga A; Bogatyrev, Nikolaj R; Bowyer, Adrian; Pahl, Anja-Karina

2006-01-01

Biomimetics, a name coined by Otto Schmitt in the 1950s for the transfer of ideas and analogues from biology to technology, has produced some significant and successful devices and concepts in the past 50 years, but is still empirical. We show that TRIZ, the Russian system of problem solving, can be adapted to illuminate and manipulate this process of transfer. Analysis using TRIZ shows that there is only 12% similarity between biology and technology in the principles which solutions to problems illustrate, and while technology solves problems largely by manipulating usage of energy, biology uses information and structure, two factors largely ignored by technology. PMID:16849244

In vitro osteoinduction of human mesenchymal stem cells in biomimetic surface modified titanium alloy implants.

PubMed

Santander, Sonia; Alcaine, Clara; Lyahyai, Jaber; Pérez, Maria Angeles; Rodellar, Clementina; Doblaré, Manuel; Ochoa, Ignacio

2012-01-01

Interaction between cells and implant surface is crucial for clinical success. This interaction and the associated surface treatment are essential for achieving a fast osseointegration process. Several studies of different topographical or chemical surface modifications have been proposed previously in literature. The Biomimetic Advanced Surface (BAS) topography is a combination of a shot blasting and anodizing procedure. Macroroughness, microporosity of titanium oxide and Calcium/Phosphate ion deposition is obtained. Human mesenchymal stem cells (hMCSs) response in vitro to this treatment has been evaluated. The results obtained show an improved adhesion capacity and a higher proliferation rate when hMSCs are cultured on treated surfaces. This biomimetic modification of the titanium surface induces the expression of osteblastic differentiation markers (RUNX2 and Osteopontin) in the absence of any externally provided differentiation factor. As a main conclusion, our biomimetic surface modification could lead to a substantial improvement in osteoinduction in titanium alloy implants.

Stabilization of Phenylalanine Ammonia Lyase from Rhodotorula glutinis by Encapsulation in Polyethyleneimine-Mediated Biomimetic Silica.

PubMed

Cui, Jiandong; Liang, Longhao; Han, Cong; Lin Liu, Rong

2015-06-01

Phenylalanine ammonia lyase (PAL) from Rhodotorula glutinis was encapsulated within polyethyleneimine-mediated biomimetic silica. The main factors in the preparation of biomimetic silica were optimized by response surface methodology (RSM). Compared to free PAL (about 2 U), the encapsulated PAL retained more than 43 % of their initial activity after 1 h of incubation time at 60 °C, whereas free PAL lost most of activity in the same conditions. It was clearly indicated that the thermal stability of PAL was improved by encapsulation. Moreover, the encapsulated PAL exhibited the excellent stability of the enzyme against denaturants and storage stability, and pH stability was improved by encapsulation. Operational stability of 7 reaction cycles showed that the encapsulated PAL was stable. Nevertheless, the K m value of encapsulated PAL in biomimetic silica was higher than that of the free PAL due to lower total surface area and increased mass transfer resistance.

Industrial-scale spray layer-by-layer assembly for production of biomimetic photonic systems.

PubMed

Krogman, K C; Cohen, R E; Hammond, P T; Rubner, M F; Wang, B N

2013-12-01

Layer-by-layer assembly is a powerful and flexible thin film process that has successfully reproduced biomimetic photonic systems such as structural colour. While most of the seminal work has been carried out using slow and ultimately unscalable immersion assembly, recent developments using spray layer-by-layer assembly provide a platform for addressing challenges to scale-up and manufacturability. A series of manufacturing systems has been developed to increase production throughput by orders of magnitude, making commercialized structural colour possible. Inspired by biomimetic photonic structures we developed and demonstrated a heat management system that relies on constructive reflection of near infrared radiation to bring about dramatic reductions in heat content.

Application of biomimetics principles in space optics

NASA Astrophysics Data System (ADS)

Remisova, K.; Hudec, R.

2017-09-01

The principles of biomimetics have been successfully applied in space optics, e.g. in Lobster-Eye X-ray optical systems. However, the recent increase in knowledge on vision of sea animals, especially on mirror eyes of scallops, crustaceans, and deep sea fishes, makes possible to consider other such applications. Especially the discoveries of mirror eyes of the deep sea fishes Dolichopteryx longipes and Rhynchohyalus natalensis are promising because of their unique arrangements and likely active optics.

Echolocation with bat buzz emissions: model and biomimetic sonar for elevation estimation.

PubMed

Kuc, Roman

2012-01-01

Just prior to capture the Buzz II emissions of some mouth-emitting bats, such as Eptesicus fuscus, are observed to exhibit spectra having multiple peaks. This paper proposes an echolocation strategy that uses such spectra with energy concentrated in specific frequency bands for determining target elevation. A biomimetic sonar was implemented to produce a tri-modal spectrum by driving a speaker with a signal rich in harmonics. The emission magnitudes at these harmonic frequencies measured as a function of elevation in the zero-azimuth plane form distinct beams. A template was formed from the ratio of the first harmonic and fundamental magnitudes to determine elevation. The elevation estimator exhibited a sub-degree accuracy (SD = 0.4° over a 20° interval centered at the elevation at which these two beams intersect in the zero-azimuth plane. Spectral cues from -40° to +10° elevation allow a qualitative non-linear control of sonar orientation to drive the target to the beam-intersection point where quantitative elevation estimates are available. © 2012 Acoustical Society of America.

Stable metal–organic frameworks as a host platform for catalysis and biomimetics

DOE PAGES

Qin, Jun-Sheng; Yuan, Shuai; Lollar, Christina; ...

2018-01-01

Recent years have witnessed the exploration and synthesis of an increasing number of metal–organic frameworks (MOFs). The utilization of stable MOFs as a platform for catalysis and biomimetics is discussed.

Nano-Engineered Biomimetic Optical Sensors for Glucose Monitoring in Diabetes.

PubMed

Rauf, Sajid; Hayat Nawaz, Muhammad Azhar; Badea, Mihaela; Marty, Jean Louis; Hayat, Akhtar

2016-11-17

Diabetes is a rapidly growing disease that can be monitored at an individual level by controlling the blood glucose level, hence minimizing the negative impact of the disease. Significant research efforts have been focused on the design of novel and improved technologies to overcome the limitations of existing glucose analysis methods. In this context, nanotechnology has enabled the diagnosis at the single cell and molecular level with the possibility of incorporation in advanced molecular diagnostic biochips. Recent years have witnessed the exploration and synthesis of various types of nanomaterials with enzyme-like properties, with their subsequent integration into the design of biomimetic optical sensors for glucose monitoring. This review paper will provide insights on the type, nature and synthesis of different biomimetic nanomaterials. Moreover, recent developments in the integration of these nanomaterials for optical glucose biosensing will be highlighted, with a final discussion on the challenges that must be addressed for successful implementation of these nano-devices in the clinical applications is presented.

Nano-Engineered Biomimetic Optical Sensors for Glucose Monitoring in Diabetes

PubMed Central

Rauf, Sajid; Hayat Nawaz, Muhammad Azhar; Badea, Mihaela; Marty, Jean Louis; Hayat, Akhtar

2016-01-01

Diabetes is a rapidly growing disease that can be monitored at an individual level by controlling the blood glucose level, hence minimizing the negative impact of the disease. Significant research efforts have been focused on the design of novel and improved technologies to overcome the limitations of existing glucose analysis methods. In this context, nanotechnology has enabled the diagnosis at the single cell and molecular level with the possibility of incorporation in advanced molecular diagnostic biochips. Recent years have witnessed the exploration and synthesis of various types of nanomaterials with enzyme-like properties, with their subsequent integration into the design of biomimetic optical sensors for glucose monitoring. This review paper will provide insights on the type, nature and synthesis of different biomimetic nanomaterials. Moreover, recent developments in the integration of these nanomaterials for optical glucose biosensing will be highlighted, with a final discussion on the challenges that must be addressed for successful implementation of these nano-devices in the clinical applications is presented. PMID:27869658

Nanocrystal Core Lipoprotein Biomimetics for Imaging of Lipoproteins and Associated Diseases.

PubMed

Fay, Francois; Sanchez-Gaytan, Brenda L; Cormode, David P; Skajaa, Torjus; Fisher, Edward A; Fayad, Zahi A; Mulder, Willem J M

2013-02-01

Lipoproteins are natural nanoparticles composed of phospholipids and apolipoproteins that transport lipids throughout the body. As key effectors of lipid homeostasis, the functions of lipoproteins have been demonstrated to be crucial during the development of cardiovascular diseases. Therefore various strategies have been used to study their biology and detect them in vivo. A recent approach has been the production of lipoprotein biomimetic particles loaded with diagnostically active nanocrystals in their core. These include, but are not limited to: quantum dots, iron oxide or gold nanocrystals. Inclusion of these nanocrystals enables the utilization of lipoproteins as probes for a variety of imaging modalities (computed tomography, magnetic resonance imaging, fluorescence) while preserving their biological activity. Furthermore as some lipoproteins naturally accumulate in atherosclerotic plaque or specific tumor tissues, nanocrystal core lipoprotein biomimetics have been developed as contrast agents for early diagnosis of these diseases.

Computational modelling of oxygenation processes in enzymes and biomimetic model complexes.

PubMed

de Visser, Sam P; Quesne, Matthew G; Martin, Bodo; Comba, Peter; Ryde, Ulf

2014-01-11

With computational resources becoming more efficient and more powerful and at the same time cheaper, computational methods have become more and more popular for studies on biochemical and biomimetic systems. Although large efforts from the scientific community have gone into exploring the possibilities of computational methods for studies on large biochemical systems, such studies are not without pitfalls and often cannot be routinely done but require expert execution. In this review we summarize and highlight advances in computational methodology and its application to enzymatic and biomimetic model complexes. In particular, we emphasize on topical and state-of-the-art methodologies that are able to either reproduce experimental findings, e.g., spectroscopic parameters and rate constants, accurately or make predictions of short-lived intermediates and fast reaction processes in nature. Moreover, we give examples of processes where certain computational methods dramatically fail.

Influence of phosphoproteins' biomimetic analogs on remineralization of mineral-depleted resin-dentin interfaces created with ion-releasing resin-based systems.

PubMed

Sauro, Salvatore; Osorio, Raquel; Watson, Timothy F; Toledano, Manuel

2015-07-01

The study aimed at evaluating the remineralization of acid-etched dentin pre-treated with primers containing biomimetic analogs and bonded using an ion-releasing light-curable resin-based material. An experimental etch-and-rinse adhesive system filled with Ca(2+), PO4(3-)-releasing Ca-Silicate micro-fillers was created along with two experimental primers containing biomimetic analogs such as sodium trimetaphosphate (TMP) and/or polyaspartic acid (PLA). Dentin specimens etched with 37% H3PO4 were pre-treated with two different aqueous primers containing the polyanionic biomimetic analogs or deionized water and subsequently bonded using the experimental resin-based materials. The specimens were sectioned and analyzed by AFM/nanoindentation to evaluate changes in the modulus of elasticity (Ei) across the resin-dentin interface at different AS storage periods (up to 90 days). Raman cluster analysis was also performed to evaluate the chemical changes along the interface. The phosphate uptake by the acid-etched dentin was evaluated using the ATR-FTIR. Additional resin-dentin specimens were tested for microtensile bond strength. SEM examination was performed after de-bonding, while confocal laser microscopy was used to evaluate the interfaces ultramorphology and micropermeability. Both biomimetic primers induced phosphate uptake by acid-etched dentin. Specimens created with the ion-releasing resin in combination with the pre-treatment primers containing either PLA and TMA showed the greatest recovery of the Ei of the hybrid layer, with no decrease in μTBS (p>0.05) after 3-month AS storage. The ion-releasing resin applied after use of the biomimetic primers showed the greatest reduction in micropermeability due to mineral precipitation; these results were confirmed using SEM. The use of the ion-releasing resin-based system applied to acid-etched dentin pre-treated with biomimetic primers containing analogs of phosphoproteins such as poly-l-aspartic acid and/or sodium

Towards a biomimetic gyroscope inspired by the fly's haltere using microelectromechanical systems technology

PubMed Central

Droogendijk, H.; Brookhuis, R. A.; de Boer, M. J.; Sanders, R. G. P.; Krijnen, G. J. M.

2014-01-01

Flies use so-called halteres to sense body rotation based on Coriolis forces for supporting equilibrium reflexes. Inspired by these halteres, a biomimetic gimbal-suspended gyroscope has been developed using microelectromechanical systems (MEMS) technology. Design rules for this type of gyroscope are derived, in which the haltere-inspired MEMS gyroscope is geared towards a large measurement bandwidth and a fast response, rather than towards a high responsivity. Measurements for the biomimetic gyroscope indicate a (drive mode) resonance frequency of about 550 Hz and a damping ratio of 0.9. Further, the theoretical performance of the fly's gyroscopic system and the developed MEMS haltere-based gyroscope is assessed and the potential of this MEMS gyroscope is discussed. PMID:25100317

Polymeric capsule-cushioned leukocyte cell membrane vesicles as a biomimetic delivery platform

NASA Astrophysics Data System (ADS)

Gao, Changyong; Wu, Zhiguang; Lin, Zhihua; Lin, Xiankun; He, Qiang

2016-02-01

We report a biomimetic delivery of microsized capsule-cushioned leukocyte membrane vesicles (CLMVs) through the conversion of freshly reassembled leukocyte membrane vesicles (LMVs), including membrane lipids and membrane-bound proteins onto the surface of layer-by-layer assembled polymeric multilayer microcapsules. The leukocyte membrane coating was verified by using electron microscopy, a quartz crystal microbalance, dynamic light scattering, and confocal laser scanning microscopy. The resulting CLMVs have the ability to effectively evade clearance by the immune system and thus prolong the circulation time in mice. Moreover, we also show that the right-side-out leukocyte membrane coating can distinctly improve the accumulation of capsules in tumor sites through the molecular recognition of membrane-bound proteins of CLMVs with those of tumor cells in vitro and in vivo. The natural cell membrane camouflaged polymeric multilayer capsules with the immunosuppressive and tumor-recognition functionalities of natural leukocytes provide a new biomimetic delivery platform for disease therapy.We report a biomimetic delivery of microsized capsule-cushioned leukocyte membrane vesicles (CLMVs) through the conversion of freshly reassembled leukocyte membrane vesicles (LMVs), including membrane lipids and membrane-bound proteins onto the surface of layer-by-layer assembled polymeric multilayer microcapsules. The leukocyte membrane coating was verified by using electron microscopy, a quartz crystal microbalance, dynamic light scattering, and confocal laser scanning microscopy. The resulting CLMVs have the ability to effectively evade clearance by the immune system and thus prolong the circulation time in mice. Moreover, we also show that the right-side-out leukocyte membrane coating can distinctly improve the accumulation of capsules in tumor sites through the molecular recognition of membrane-bound proteins of CLMVs with those of tumor cells in vitro and in vivo. The natural

Biomimetic robots using EAP as artificial muscles - progress and challenges

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph

2004-01-01

Biology offers a great model for emulation in areas ranging from tools, computational algorithms, materials science, mechanisms and information technology. In recent years, the field of biomimetics, namely mimicking biology, has blossomed with significant advances enabling the reverse engineering of many animals' functions and implementation of some of these capabilities.

Biomimetics of fetal alveolar flow phenomena using microfluidics.

PubMed

Tenenbaum-Katan, Janna; Fishler, Rami; Rothen-Rutishauser, Barbara; Sznitman, Josué

2015-01-01

At the onset of life in utero, the respiratory system begins as a liquid-filled tubular organ and undergoes significant morphological changes during fetal development towards establishing a respiratory organ optimized for gas exchange. As airspace morphology evolves, respiratory alveolar flows have been hypothesized to exhibit evolving flow patterns. In the present study, we have investigated flow topologies during increasing phases of embryonic life within an anatomically inspired microfluidic device, reproducing real-scale features of fetal airways representative of three distinct phases of in utero gestation. Micro-particle image velocimetry measurements, supported by computational fluid dynamics simulations, reveal distinct respiratory alveolar flow patterns throughout different stages of fetal life. While attached, streamlined flows characterize the shallow structures of premature alveoli indicative of the onset of saccular stage, separated recirculating vortex flows become the signature of developed and extruded alveoli characteristic of the advanced stages of fetal development. To further mimic physiological aspects of the cellular environment of developing airways, our biomimetic devices integrate an alveolar epithelium using the A549 cell line, recreating a confluent monolayer that produces pulmonary surfactant. Overall, our in vitro biomimetic fetal airways model delivers a robust and reliable platform combining key features of alveolar morphology, flow patterns, and physiological aspects of fetal lungs developing in utero.

Biomimetic Polyaminoacids as Precursors for Optical-Active Intelligent Materials

DTIC Science & Technology

2003-06-17

discuss several properties of biomimetic polyaminoacid derivatives in solutions, monolayers and Langmuir - Blodgette films. Principal strategy such as...dependences of surface pressure on area per one molecule under compression of monolayer (P-A compres- sion isoterms). Y-type Langmuir - Blodgett films for...switches construction. Inorganic- organic hybrids with cyclophosphazene cores (star-like design of poly -glutamic or poly -alanine) are the convient ma

Nanocrystal Core Lipoprotein Biomimetics for Imaging of Lipoproteins and Associated Diseases

PubMed Central

Fay, Francois; Sanchez-Gaytan, Brenda L.; Cormode, David P.; Skajaa, Torjus; Fisher, Edward A.; Fayad, Zahi A.

2013-01-01

Lipoproteins are natural nanoparticles composed of phospholipids and apolipoproteins that transport lipids throughout the body. As key effectors of lipid homeostasis, the functions of lipoproteins have been demonstrated to be crucial during the development of cardiovascular diseases. Therefore various strategies have been used to study their biology and detect them in vivo. A recent approach has been the production of lipoprotein biomimetic particles loaded with diagnostically active nanocrystals in their core. These include, but are not limited to: quantum dots, iron oxide or gold nanocrystals. Inclusion of these nanocrystals enables the utilization of lipoproteins as probes for a variety of imaging modalities (computed tomography, magnetic resonance imaging, fluorescence) while preserving their biological activity. Furthermore as some lipoproteins naturally accumulate in atherosclerotic plaque or specific tumor tissues, nanocrystal core lipoprotein biomimetics have been developed as contrast agents for early diagnosis of these diseases. PMID:23687557

Biomimetic Modeling of Copper Complexes: A Study of Enantioselective Catalytic Oxidation on D-(+)-Catechin and L-( − )-Epicatechin with Copper Complexes

PubMed Central

Mutti, Francesco G.; Pievo, Roberta; Sgobba, Maila; Gullotti, Michele; Santagostini, Laura

2008-01-01

The biomimetic catalytic oxidations of the dinuclear and trinuclear copper(II) complexes versus two catechols, namely, D-(+)-catechin and L-( − )-epicatechin to give the corresponding quinones are reported. The unstable quinones were trapped by the nucleophilic reagent, 3-methyl-2-benzothiazolinone hydrazone (MBTH), and have been calculated the molar absorptivities of the different quinones. The catalytic efficiency is moderate, as inferred by kinetic constants, but the complexes exhibit significant enantio-differentiating ability towards the catechols, albeit for the dinuclear complexes, this enantio-differentiating ability is lower. In all cases, the preferred enantiomeric substrate is D-(+)-catechin to respect the other catechol, because of the spatial disposition of this substrate. PMID:18825268

Controlling the Biomimetic Implant Interface: Modulating Antimicrobial Activity by Spacer Design

NASA Astrophysics Data System (ADS)

Wisdom, Cate; Vanoosten, Sarah Kay; Boone, Kyle W.; Khvostenko, Dmytro; Arnold, Paul M.; Snead, Malcolm L.; Tamerler, Candan

2016-08-01

Surgical site infection is a common cause of post-operative morbidity, often leading to implant loosening, ultimately requiring revision surgery, increased costs and worse surgical outcomes. Since implant failure starts at the implant surface, creating and controlling the bio-material interface will play a critical role in reducing infection while improving host cell-to-implant interaction. Here, we engineered a biomimetic interface based upon a chimeric peptide that incorporates a titanium binding peptide (TiBP) with an antimicrobial peptide (AMP) into a single molecule to direct binding to the implant surface and deliver an antimicrobial activity against S. mutans and S. epidermidis, two bacteria which are linked with clinical implant infections. To optimize antimicrobial activity, we investigated the design of the spacer domain separating the two functional domains of the chimeric peptide. Lengthening and changing the amino acid composition of the spacer resulted in an improvement of minimum inhibitory concentration by a three-fold against S. mutans. Surfaces coated with the chimeric peptide reduced dramatically the number of bacteria, with up to a nine-fold reduction for S. mutans and a 48-fold reduction for S. epidermidis. Ab initio predictions of antimicrobial activity based on structural features were confirmed. Host cell attachment and viability at the biomimetic interface were also improved compared to the untreated implant surface. Biomimetic interfaces formed with this chimeric peptide offer interminable potential by coupling antimicrobial and improved host cell responses to implantable titanium materials, and this peptide based approach can be extended to various biomaterials surfaces.

Gambogic acid-loaded biomimetic nanoparticles in colorectal cancer treatment

PubMed Central

Zhang, Zhen; Qian, Hanqing; Yang, Mi; Li, Rutian; Hu, Jing; Li, Li; Yu, Lixia; Liu, Baorui; Qian, Xiaoping

2017-01-01

Gambogic acid (GA) is expected to be a potential new antitumor drug, but its poor aqueous solubility and inevitable side effects limit its clinical application. Despite these inhe rent defects, various nanocarriers can be used to promote the solubility and tumor targeting of GA, improving antitumor efficiency. In addition, a cell membrane-coated nanoparticle platform that was reported recently, unites the customizability and flexibility of a synthetic copolymer, as well as the functionality and complexity of natural membrane, and is a new synthetic biomimetic nanocarrier with improved stability and biocompatibility. Here, we combined poly(lactic-co-glycolic acid) (PLGA) with red blood-cell membrane (RBCm), and evaluated whether GA-loaded RBCm nanoparticles can retain and improve the antitumor efficacy of GA with relatively lower toxicity in colorectal cancer treatment compared with free GA. We also confirmed the stability, biocompatibility, passive targeting, and few side effects of RBCm-GA/PLGA nanoparticles. We expect to provide a new drug carrier in the treatment of colorectal cancer, which has strong clinical application prospects. In addition, the potential antitumor drug GA and other similar drugs could achieve broader clinical applications via this biomimetic nanocarrier. PMID:28280328

Advances in surfaces and osseointegration in implantology. Biomimetic surfaces

PubMed Central

Albertini, Matteo; Fernandez-Yague, Marc; Lázaro, Pedro; Herrero-Climent, Mariano; Bullon, Pedro; Gil, Francisco-Javier

2015-01-01

The present work is a revision of the processes occurring in osseointegration of titanium dental implants according to different types of surfaces -namely, polished surfaces, rough surfaces obtained from subtraction methods, as well as the new hydroxyapatite biomimetic surfaces obtained from thermochemical processes. Hydroxyapatite’s high plasma-projection temperatures have proven to prevent the formation of crystalline apatite on the titanium dental implant, but lead to the formation of amorphous calcium phosphate (i.e., with no crystal structure) instead. This layer produce some osseointegration yet the calcium phosphate layer will eventually dissolve and leave a gap between the bone and the dental implant, thus leading to osseointegration failure due to bacterial colonization. A new surface -recently obtained by thermochemical processes- produces, by crystallization, a layer of apatite with the same mineral content as human bone that is chemically bonded to the titanium surface. Osseointegration speed was tested by means of minipigs, showing bone formation after 3 to 4 weeks, with the security that a dental implant can be loaded. This surface can be an excellent candidate for immediate or early loading procedures. Key words:Dental implants, implants surfaces, osseointegration, biomimetics surfaces. PMID:25662555

Nano-biomimetics for nano/micro tissue regeneration.

PubMed

Singh, Dolly; Singh, Deepti; Zo, Sunmi; Han, Sung Soo

2014-10-01

Nanostructured biomimetics have recently shown great promise in the field of tissue engineering. They can be used as nanoscaffolds and tailored at the molecular level. The scaffold topography closely resembles the native extracellular matrix in terms of framing, porosity and bio-functionality. This review covers the approaches used for biomimetic fabrication, including soft lithography, the plasmonic nanohybrid matrix method and multilayer self-assembly scaffolds for tissue regeneration. It brings together knowledge from different arenas about the synthesis, characterization and functionalization of matrices to accelerate the tissue regeneration process. Every tissue in the body presents different challenges and requires a specific fabrication process designed to identify and mirror the particular organ. For example, microfluidics systems aim to mimic the extracellular matrix of vascular and cartilage tissue, and these systems have different parts with completely different mechanical strength, cellular adhesion and interplay between matrix and cells. A fully functional nanomatrix designed by a self-assembling methodology for use as a vascular tissue engineering scaffold needs to have intrinsic microvessels that facilitate the transportation of metabolites and nutrients. Similarly, in the case of peripheral nerve regeneration, a scaffold needs to have sufficient mechanical strength to protect the regenerating tissue, yet be biodegradable enough to avoid a possible second surgery. To enhance the functionality of scaffolds, increasing focus has been placed on in vitro and in vivo research to achieve optimal scaffold design. Nanobiomimetics unarguably offer the most suitable physicochemical scaffold properties for tissue regeneration.

Superhydrophobic hierarchically structured surfaces in biology: evolution, structural principles and biomimetic applications

PubMed Central

Mail, M.; Neinhuis, C.

2016-01-01

A comprehensive survey of the construction principles and occurrences of superhydrophobic surfaces in plants, animals and other organisms is provided and is based on our own scanning electron microscopic examinations of almost 20 000 different species and the existing literature. Properties such as self-cleaning (lotus effect), fluid drag reduction (Salvinia effect) and the introduction of new functions (air layers as sensory systems) are described and biomimetic applications are discussed: self-cleaning is established, drag reduction becomes increasingly important, and novel air-retaining grid technology is introduced. Surprisingly, no evidence for lasting superhydrophobicity in non-biological surfaces exists (except technical materials). Phylogenetic trees indicate that superhydrophobicity evolved as a consequence of the conquest of land about 450 million years ago and may be a key innovation in the evolution of terrestrial life. The approximate 10 million extant species exhibit a stunning diversity of materials and structures, many of which are formed by self-assembly, and are solely based on a limited number of molecules. A short historical survey shows that bionics (today often called biomimetics) dates back more than 100 years. Statistical data illustrate that the interest in biomimetic surfaces is much younger still. Superhydrophobicity caught the attention of scientists only after the extreme superhydrophobicity of lotus leaves was published in 1997. Regrettably, parabionic products play an increasing role in marketing. This article is part of the themed issue ‘Bioinspired hierarchically structured surfaces for green science’. PMID:27354736

Superhydrophobic hierarchically structured surfaces in biology: evolution, structural principles and biomimetic applications.

PubMed

Barthlott, W; Mail, M; Neinhuis, C

2016-08-06

A comprehensive survey of the construction principles and occurrences of superhydrophobic surfaces in plants, animals and other organisms is provided and is based on our own scanning electron microscopic examinations of almost 20 000 different species and the existing literature. Properties such as self-cleaning (lotus effect), fluid drag reduction (Salvinia effect) and the introduction of new functions (air layers as sensory systems) are described and biomimetic applications are discussed: self-cleaning is established, drag reduction becomes increasingly important, and novel air-retaining grid technology is introduced. Surprisingly, no evidence for lasting superhydrophobicity in non-biological surfaces exists (except technical materials). Phylogenetic trees indicate that superhydrophobicity evolved as a consequence of the conquest of land about 450 million years ago and may be a key innovation in the evolution of terrestrial life. The approximate 10 million extant species exhibit a stunning diversity of materials and structures, many of which are formed by self-assembly, and are solely based on a limited number of molecules. A short historical survey shows that bionics (today often called biomimetics) dates back more than 100 years. Statistical data illustrate that the interest in biomimetic surfaces is much younger still. Superhydrophobicity caught the attention of scientists only after the extreme superhydrophobicity of lotus leaves was published in 1997. Regrettably, parabionic products play an increasing role in marketing.This article is part of the themed issue 'Bioinspired hierarchically structured surfaces for green science'. © 2016 The Author(s).

Bio-microfluidics: biomaterials and biomimetic designs.

PubMed

Domachuk, Peter; Tsioris, Konstantinos; Omenetto, Fiorenzo G; Kaplan, David L

2010-01-12

Bio-microfluidics applies biomaterials and biologically inspired structural designs (biomimetics) to microfluidic devices. Microfluidics, the techniques for constraining fluids on the micrometer and sub-micrometer scale, offer applications ranging from lab-on-a-chip to optofluidics. Despite this wealth of applications, the design of typical microfluidic devices imparts relatively simple, laminar behavior on fluids and is realized using materials and techniques from silicon planar fabrication. On the other hand, highly complex microfluidic behavior is commonplace in nature, where fluids with nonlinear rheology flow through chaotic vasculature composed from a range of biopolymers. In this Review, the current state of bio-microfluidic materials, designs and applications are examined. Biopolymers enable bio-microfluidic devices with versatile functionalization chemistries, flexibility in fabrication, and biocompatibility in vitro and in vivo. Polymeric materials such as alginate, collagen, chitosan, and silk are being explored as bulk and film materials for bio-microfluidics. Hydrogels offer options for mechanically functional devices for microfluidic systems such as self-regulating valves, microlens arrays and drug release systems, vital for integrated bio-microfluidic devices. These devices including growth factor gradients to study cell responses, blood analysis, biomimetic capillary designs, and blood vessel tissue culture systems, as some recent examples of inroads in the field that should lead the way in a new generation of microfluidic devices for bio-related needs and applications. Perhaps one of the most intriguing directions for the future will be fully implantable microfluidic devices that will also integrate with existing vasculature and slowly degrade to fully recapitulate native tissue structure and function, yet serve critical interim functions, such as tissue maintenance, drug release, mechanical support, and cell delivery.

Biomimetic design in microparticulate vaccines.

PubMed

Keegan, Mark E; Whittum-Hudson, Judith A; Mark Saltzman, W

2003-11-01

Current efforts to improve the effectiveness of microparticle vaccines include incorporating biomimetic features into the particles. Many pathogens use surface molecules to target specific cell types in the gut for host invasion. This observation has inspired efforts to chemically conjugate cell-type targeting ligands to the surfaces of microparticles in order to increase the efficiency of uptake, and therefore the effectiveness, of orally administered microparticles. Bio-mimicry is not limited to the exterior surface of the microparticles. Anti-idiotypic antibodies, cytokines or other biological modifiers can be encapsulated for delivery to sites of interest as vaccines or other therapeutics. Direct mucosal delivery of microparticle vaccines or immunomodulatory agents may profoundly enhance mucosal and systemic immune responses compared to other delivery routes.

A novel soft biomimetic microrobot with two motion attitudes.

PubMed

Shi, Liwei; Guo, Shuxiang; Li, Maoxun; Mao, Shilian; Xiao, Nan; Gao, Baofeng; Song, Zhibin; Asaka, Kinji

2012-12-06

 A variety of microrobots have commonly been used in the fields of biomedical engineering and underwater operations during the last few years. Thanks to their compact structure, low driving power, and simple control systems, microrobots can complete a variety of underwater tasks, even in limited spaces. To accomplish our objectives, we previously designed several bio-inspired underwater microrobots with compact structure, flexibility, and multi-functionality, using ionic polymer metal composite (IPMC) actuators. To implement high-position precision for IPMC legs, in the present research, we proposed an electromechanical model of an IPMC actuator and analysed the deformation and actuating force of an equivalent IPMC cantilever beam, which could be used to design biomimetic legs, fingers, or fins for an underwater microrobot. We then evaluated the tip displacement of an IPMC actuator experimentally. The experimental deflections fit the theoretical values very well when the driving frequency was larger than 1 Hz. To realise the necessary multi-functionality for adapting to complex underwater environments, we introduced a walking biomimetic microrobot with two kinds of motion attitudes: a lying state and a standing state. The microrobot uses eleven IPMC actuators to move and two shape memory alloy (SMA) actuators to change its motion attitude. In the lying state, the microrobot implements stick-insect-inspired walking/rotating motion, fish-like swimming motion, horizontal grasping motion, and floating motion. In the standing state, it implements inchworm-inspired crawling motion in two horizontal directions and grasping motion in the vertical direction. We constructed a prototype of this biomimetic microrobot and evaluated its walking, rotating, and floating speeds experimentally. The experimental results indicated that the robot could attain a maximum walking speed of 3.6 mm/s, a maximum rotational speed of 9°/s, and a maximum floating speed of 7.14 mm/s. Obstacle

Bio-mimetic mineralization potential of collagen hydrolysate obtained from chromium tanned leather waste.

PubMed

Banerjee, Pradipta; Madhu, S; Chandra Babu, N K; Shanthi, C

2015-04-01

Hydroxyapatite (HA) ceramics serve as an alternative to autogenous-free bone grafting by virtue of their excellent biocompatibility. However, chemically synthesized HA lacks the strong load-bearing capacity as required by bone. The bio-mimetic growth of HA crystals on collagen surface provides a feasible solution for synthesizing bone substitutes with the desired properties. This study deals with the utilization of the collagen hydrolysate recovered from leather waste as a substrate for promoting HA crystal growth. Bio-mimetic growth of HA was induced by subjecting the hydrolysate to various mineralization conditions. Parameters that would have a direct effect on crystal growth were varied to determine the optimal conditions necessary. Maximum mineralization was achieved with a combination of 10mM of CaCl2, 5mM of Na2HPO4, 100mM of NaCl and 0.575% glutaraldehyde at a pH of 7.4. The metal-protein interactions leading to formation of HA were identified through Fourier-transform infrared (FTIR) spectroscopy and x-ray diffraction (XRD) studies. The crystal dimensions were determined to be in the nanoscale range by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The size and crystallinity of bio-mimetically grown HA indicate that hydrolysate from leather waste can be used as an ideal alternative substrate for bone growth. Copyright © 2015 Elsevier B.V. All rights reserved.

Substantial Differentiation of Human Neural Stem Cells Into Motor Neurons on a Biomimetic Polyureaa

PubMed Central

Yun, Donghwa; Lee, Young M.; Laughter, Melissa R.; Freed, Curt R.

2015-01-01

To find the first restorative treatment for spinal cord injury (SCI), researchers have focused on stem cell therapies. However, one obstacle is the lack of an implantable cell scaffold that can support efficient motor neuron (MN) differentiation and proliferation. We aimed to overcome this through the use of an RGD functionalized novel biomimetic polyurea, optimized to encourage efficient differentiation of MNs. Images taken after 14-days showed increased differentiation (~40%) of hNSCs into MNs as well as increased cell count on the biomimetic polymer compared to PDL-Laminin coating, indicating that the RGD-polyurea provides a favorable microenvironment for hNSC survival, having promising implications for future SCI therapies. PMID:26033933

A crude protective film on historic stones and its artificial preparation through biomimetic synthesis

NASA Astrophysics Data System (ADS)

Liu, Qiang; Zhang, Bingjian; Shen, Zhongyue; Lu, Huanming

2006-12-01

A biomimetic film has been found on the surface of the historic stone buildings and monuments. The stone inscriptions under the film are preserved so well that has not been damaged for more than 1000 years. Samples of the crude film have been analyzed by XRD, FTIR, PLM, EDA, SEM and TEM. The results show that it consists mainly of calcium oxalate monohydrate. On the basis of the existence of the organism debris, it is concluded that the film should be a product of biomineralization. According to this hypothesis, a similar film has been prepared on the stone surface through biomimetic synthesis in our laboratory. The preliminary analysis shows that the artificial protective film functions well.

Dual-responsive and Multi-functional Plasmonic Hydrogel Valves and Biomimetic Architectures Formed with Hydrogel and Gold Nanocolloids

PubMed Central

Song, Ji Eun; Cho, Eun Chul

2016-01-01

We present a straightforward approach with high moldability for producing dual-responsive and multi-functional plasmonic hydrogel valves and biomimetic architectures that reversibly change volumes and colors in response to temperature and ion variations. Heating of a mixture of hybrid colloids (gold nanoparticles assembled on a hydrogel colloid) and hydrogel colloids rapidly induces (within 30 min) the formation of hydrogel architectures resembling mold shapes (cylinder, fish, butterfly). The biomimetic fish and butterfly display reversible changes in volumes and colors with variations of temperature and ionic conditions in aqueous solutions. The cylindrical plasmonic valves installed in flow tubes rapidly control water flow rate in on-off manner by responding to these stimuli. They also report these changes in terms of their colors. Therefore, the approach presented here might be helpful in developing new class of biomimetic and flow control systems where liquid conditions should be visually notified (e.g., glucose or ion concentration changes). PMID:27703195

Biomimetic/Bioinspired Design of Enzyme@capsule Nano/Microsystems.

PubMed

Shi, J; Jiang, Y; Zhang, S; Yang, D; Jiang, Z

2016-01-01

Enzyme@capsule nano/microsystems, which refer to the enzyme-immobilized capsules, have received tremendous interest owing to the combination of the high catalytic activities of encapsulated enzymes and the hierarchical structure of the capsule. The preparation of capsules and simultaneous encapsulation of enzymes is recognized as the core process for the rational design and construction of enzyme@capsule nano/microsystems. The strategy used has three major steps: (a) generation of the templates, (b) surface coating on the templates, and (c) removal of the templates, and it has been proven to be effective and versatile for the construction of enzyme@capsule nano/microsystems. Several conventional methods, including layer-by-layer assembly of polyelectrolytes, liquid crystalline templating method, etc., were used to design and construct enzyme@capsule nano/microsystems, but these have two major drawbacks. One is the low mechanical stability of the systems and the second is the harsh conditions used in the construction process. Learning from nature, several biomimetic/bioinspired methods such as biomineralization, biomimetic/bioinspired adhesion, and their combination have been exploited for the construction of enzyme@capsule nano/microsystems. In this chapter, we will present a general protocol for the construction of enzyme@capsule nano/microsystems using the latter approach. Some suggestions for improved design, construction, and characterization will also be presented with detailed procedures for specific examples. © 2016 Elsevier Inc. All rights reserved.

Pore-Confined Carriers and Biomolecules in Mesoporous Silica for Biomimetic Separation and Targeting

NASA Astrophysics Data System (ADS)

Zhou, Shanshan

Selectively permeable biological membranes composed of lipophilic barriers inspire the design of biomimetic carrier-mediated membranes for aqueous solute separation. This work imparts selective permeability to lipid-filled pores of silica thin film composite membranes using carrier molecules that reside in the lipophilic self-assemblies. The lipids confined inside the pores of silica are proven to be a more effective barrier than bilayers formed on the porous surface through vesicle fusion, which is critical for quantifying the function of an immobilized carrier. The ability of a lipophilic carrier embedded in the lipid bilayer to reversibly bind the target solute and transport it through the membrane is demonstrated. Through the functionalization of the silica surface with enzymes, enzymatic catalysis and biomimetic separations can be combined on this nanostructured composite platform. The successful development of biomimetic nanocomposite membrane can provide for efficient dilute aqueous solute upgrading or separations using engineered carrier/catalyst/support systems. While the carrier-mediated biomimetic membranes hold great potential, fully understanding of the transport processes in composite synthetic membranes is essential for improve the membrane performance. Electrochemical impedance spectroscopy (EIS) technique is demonstrated to be a useful tool for characterizing the thin film pore accessibility. Furthermore, the effect of lipid bilayer preparation methods on the silica thin film (in the form of pore enveloping, pore filling) on ion transport is explored, as a lipid bilayer with high electrically insulation is essential for detecting activity of proteins or biomimetic carriers in the bilayer. This study provides insights for making better barriers on mesoporous support for carrier-mediated membrane separation process. Porous silica nanoparticles (pSNPs) with pore sizes appropriate for biomolecule loading are potential for encapsulating dsRNA within the

Ion implantation modified stainless steel as a substrate for hydroxyapatite deposition. Part II. Biomimetic layer growth and characterization.

PubMed

Pramatarova, L; Pecheva, E; Krastev, V

2007-03-01

The interest in stainless steel as a material widely used in medicine and dentistry has stimulated extensive studies on improving its bone-bonding properties. AISI 316 stainless steel is modified by a sequential ion implantation of Ca and P ions (the basic ions of hydroxyapatite), and by Ca and P implantation and subsequent thermal treatment in air (600( composite function)C, 1 h). This paper investigates the ability of the as-modified surfaces to induce hydroxyapatite deposition by using a biomimetic approach, i.e. immersion in a supersaturated aqueous solution resembling the human blood plasma (the so-called simulated body fluid). We describe our experimental procedure and results, and discuss the physico-chemical properties of the deposed hydroxyapatite on the modified stainless steel surfaces. It is shown that the implantation of a selected combination of ions followed by the applied methodology of the sample soaking in the simulated body fluid yield the growth of hydroxyapatite layers with composition and structure resembling those of the bone apatite. The grown layers are found suitable for studying the process of mineral formation in nature (biomineralization).

Biomimetic synthesis of highly biocompatible gold nanoparticles with amino acid-dithiocarbamate as a precursor for SERS imaging

NASA Astrophysics Data System (ADS)

Li, Li; Liu, Jianbo; Yang, Xiaohai; Huang, Jin; He, Dinggeng; Guo, Xi; Wan, Lan; He, Xiaoxiao; Wang, Kemin

2016-03-01

Amino acid-dithiocarbamate (amino acid-DTC) was developed as both the reductant and ligand stabilizer for biomimetic synthesis of gold nanoparticles (AuNPs), which served as an excellent surface-enhanced Raman scattering (SERS) contrast nanoprobe for cell imaging. Glycine (Gly), glutamic acid (Glu), and histidine (His) with different isoelectric points were chosen as representative amino acid candidates to synthesize corresponding amino acid-DTC compounds through mixing with carbon disulfide (CS2), respectively. The pyrogenic decomposition of amino acid-DTC initiated the reduction synthesis of AuNPs, and the strong coordinating dithiocarbamate group of amino acid-DTC served as a stabilizer that grafted onto the surface of the AuNPs, which rendered the as-prepared nanoparticles a negative surface charge and high colloidal stability. MTT cell viability assay demonstrated that the biomimetic AuNPs possessed neglectful toxicity to the human hepatoma cell, which guaranteed them good biocompatibility for biomedical application. Meanwhile, the biomimetic AuNPs showed a strong SERS effect with an enhancement factor of 9.8 × 105 for the sensing of Rhodamine 6G, and two distinct Raman peaks located at 1363 and 1509 cm-1 could be clearly observed in the cell-imaging experiments. Therefore, biomimetic AuNPs can be explored as an excellent SERS contrast nanoprobe for biomedical imaging, and the amino acid-DTC mediated synthesis of the AuNPs has a great potential in bio-engineering and biomedical imaging applications.

Biomimetic mechanism for micro aircraft

NASA Technical Reports Server (NTRS)

Pines, Darryll J. (Inventor); Bohorquez, Felipe A. (Inventor); Sirohi, Jayant (Inventor)

2005-01-01

A biomimetic pitching and flapping mechanism including a support member, at least two blade joints for holding blades and operatively connected to the support member. An outer shaft member is concentric with the support member, and an inner shaft member is concentric with the outer shaft member. The mechanism allows the blades of a small-scale rotor to be actuated in the flap and pitch degrees of freedom. The pitching and the flapping are completely independent from and uncoupled to each other. As such, the rotor can independently flap, or independently pitch, or flap and pitch simultaneously with different amplitudes and/or frequencies. The mechanism can also be used in a non-rotary wing configuration, such as an ornithopter, in which case the rotational degree of freedom would be suppressed.

Biomimetic artificial sphincter muscles: status and challenges

NASA Astrophysics Data System (ADS)

Leung, Vanessa; Fattorini, Elisa; Karapetkova, Maria; Osmani, Bekim; Töpper, Tino; Weiss, Florian; Müller, Bert

2016-04-01

Fecal incontinence is the involuntary loss of bowel content and affects more than 12% of the adult population, including 45% of retirement home residents. Severe fecal incontinence is often treated by implanting an artificial sphincter. Currently available implants, however, have long-term reoperation rates of 95% and definitive explantation rates of 40%. These statistics show that the implants fail to reproduce the capabilities of the natural sphincter and that the development of an adaptive, biologically inspired implant is required. Dielectric elastomer actuators (DEA) are being developed as artificial muscles for a biomimetic sphincter, due to their suitable response time, reaction forces, and energy consumption. However, at present the operation voltage of DEAs is too high for artificial muscles implanted in the human body. To reduce the operating voltage to tens of volts, we are using microfabrication to reduce the thickness of the elastomer layer to the nanometer level. Two microfabrication methods are being investigated: molecular beam deposition and electrospray deposition. This communication covers the current status and a perspective on the way forward, including the long-term prospects of constructing a smart sphincter from low-voltage sensors and actuators based on nanometer-thin dielectric elastomer films. As DEA can also provide sensory feedback, a biomimetic sphincter can be designed in accordance with the geometrical and mechanical parameters of its natural counterpart. The availability of such technology will enable fast pressure adaption comparable to the natural feedback mechanism, so that tissue atrophy and erosion can be avoided while maintaining continence du ring daily activities.

Fabrication and characterization of biomimetic ceramic/polymer composite materials for dental restoration.

PubMed

Petrini, Morena; Ferrante, Maurizio; Su, Bo

2013-04-01

Conventional dental composites with randomly dispersed inorganic particles within a polymer matrix fail to recapitulate the aligned and anisotropic structure of the dentin and enamel. The aim of the study was to produce a biomimetic composite consisting of a ceramic preform with graded and continuously aligned open pores, infiltrated with epoxy resin. The freeze casting technique was used to obtain the hierarchically structured architecture of the ceramic preforms. Optical and scanning electron microscopy (SEM) and differential thermal analysis and thermogravimetry (TG-DTA) were used to characterize the samples. Three point bending test and compression test were also performed. All analysis confirmed that the biomimetic composite was characterized by a multi-level hierarchical structure along the freezing direction. In the bottom layers close to the cooling plate (up to 2mm thick), a randomly packed ceramic with closed pores were formed, which resulted in incomplete infiltration with resin and resultant poor mechanical propertiesof the composite. Above 2mm, all ceramic samples showed an aligned structure with an increasing lamellae spacing (wavelength) and a decreasing wall thickness. Mechanical tests showed that the properties of the composites made from ceramic preforms above 2mm from cooling plate are similar to those of the dentin. The fabrication processing reported in this work offers a viable route for the fabrication of biomimetic composites, which could be potentially used in a range of dental restorations to compete with the current dental composites and ceramics. Copyright © 2012 Academy of Dental Materials. All rights reserved.

Biomimetics inspired surfaces for drag reduction and oleophobicity/philicity.

PubMed

Bhushan, Bharat

2011-01-01

The emerging field of biomimetics allows one to mimic biology or nature to develop nanomaterials, nanodevices, and processes which provide desirable properties. Hierarchical structures with dimensions of features ranging from the macroscale to the nanoscale are extremely common in nature and possess properties of interest. There are a large number of objects including bacteria, plants, land and aquatic animals, and seashells with properties of commercial interest. Certain plant leaves, such as lotus (Nelumbo nucifera) leaves, are known to be superhydrophobic and self-cleaning due to the hierarchical surface roughness and presence of a wax layer. In addition to a self-cleaning effect, these surfaces with a high contact angle and low contact angle hysteresis also exhibit low adhesion and drag reduction for fluid flow. An aquatic animal, such as a shark, is another model from nature for the reduction of drag in fluid flow. The artificial surfaces inspired from the shark skin and lotus leaf have been created, and in this article the influence of structure on drag reduction efficiency is reviewed. Biomimetic-inspired oleophobic surfaces can be used to prevent contamination of the underwater parts of ships by biological and organic contaminants, including oil. The article also reviews the wetting behavior of oil droplets on various superoleophobic surfaces created in the lab.

Alkane Oxidation: Methane Monooxygenases, Related Enzymes, and Their Biomimetics.

PubMed

Wang, Vincent C-C; Maji, Suman; Chen, Peter P-Y; Lee, Hung Kay; Yu, Steve S-F; Chan, Sunney I

2017-07-12

Methane monooxygenases (MMOs) mediate the facile conversion of methane into methanol in methanotrophic bacteria with high efficiency under ambient conditions. Because the selective oxidation of methane is extremely challenging, there is considerable interest in understanding how these enzymes carry out this difficult chemistry. The impetus of these efforts is to learn from the microbes to develop a biomimetic catalyst to accomplish the same chemical transformation. Here, we review the progress made over the past two to three decades toward delineating the structures and functions of the catalytic sites in two MMOs: soluble methane monooxygenase (sMMO) and particulate methane monooxygenase (pMMO). sMMO is a water-soluble three-component protein complex consisting of a hydroxylase with a nonheme diiron catalytic site; pMMO is a membrane-bound metalloenzyme with a unique tricopper cluster as the site of hydroxylation. The metal cluster in each of these MMOs harnesses O 2 to functionalize the C-H bond using different chemistry. We highlight some of the common basic principles that they share. Finally, the development of functional models of the catalytic sites of MMOs is described. These efforts have culminated in the first successful biomimetic catalyst capable of efficient methane oxidation without overoxidation at room temperature.

Biomimetic molecular design tools that learn, evolve, and adapt.

PubMed

Winkler, David A

2017-01-01

A dominant hallmark of living systems is their ability to adapt to changes in the environment by learning and evolving. Nature does this so superbly that intensive research efforts are now attempting to mimic biological processes. Initially this biomimicry involved developing synthetic methods to generate complex bioactive natural products. Recent work is attempting to understand how molecular machines operate so their principles can be copied, and learning how to employ biomimetic evolution and learning methods to solve complex problems in science, medicine and engineering. Automation, robotics, artificial intelligence, and evolutionary algorithms are now converging to generate what might broadly be called in silico-based adaptive evolution of materials. These methods are being applied to organic chemistry to systematize reactions, create synthesis robots to carry out unit operations, and to devise closed loop flow self-optimizing chemical synthesis systems. Most scientific innovations and technologies pass through the well-known "S curve", with slow beginning, an almost exponential growth in capability, and a stable applications period. Adaptive, evolving, machine learning-based molecular design and optimization methods are approaching the period of very rapid growth and their impact is already being described as potentially disruptive. This paper describes new developments in biomimetic adaptive, evolving, learning computational molecular design methods and their potential impacts in chemistry, engineering, and medicine.

Advanced Biomimetic Implants Based on Nanostructured Coatings Synthesized by Pulsed Laser Technologies

NASA Astrophysics Data System (ADS)

Mihailescu, Ion N.; Ristoscu, Carmen; Bigi, Adriana; Mayer, Isaac

Calcium phosphates (CaPs) are alternative substitutes for human bones and so primary candidates for the manufacture of medical implants. Unfortunately, they do not withstand stress in bulk. To overcome this obstacle, a solution was developed to cover metallic implants with functional biomimetic layers.

Biomimetic graphene sensors: functionalizing graphene with peptides

NASA Astrophysics Data System (ADS)

Ishigami, Masa; Nyon Kim, Sang; Naik, Rajesh; Tatulian, Suren A.; Katoch, Jyoti

2012-02-01

Non-covalent biomimetic functionalization of graphene using peptides is one of more promising methods for producing novel sensors with high sensitivity and selectivity. Here we combine atomic force microscopy, Raman spectroscopy, and attenuated total reflection Fourier transform infrared spectroscopy to investigate peptide binding to graphene and graphite. We choose to study a dodecamer peptide identified with phage display to possess affinities for graphite and we find that the peptide forms a complex mesh-like structure upon adsorption on graphene. Moreover, optical spectroscopy reveals that the peptide binds non-covalently to graphene and possesses an optical signature of an ?-helical conformation on graphene.

Biomimetic Composite Scaffold for Breast Reconstruction Following Tumor Resection

DTIC Science & Technology

2005-09-01

developing an innovative biomimetic scaffold materials by combining two natural polymers: silk fibroin (from Bombyx mori silk worm) and chitosan (from...M.D. Anderson Cancer Center (UTMDACC) is a component of the University of Texas System. It is one of the nation’s original three Comprehensive Cancer...follow protocols • Properly collect, measure, and document data from the lab, clinic, and/or animal facilities 22 Table 2. Origin of Country and

Biomimetic nanocrystalline apatites: Emerging perspectives in cancer diagnosis and treatment.

PubMed

Al-Kattan, Ahmed; Girod-Fullana, Sophie; Charvillat, Cédric; Ternet-Fontebasso, Hélène; Dufour, Pascal; Dexpert-Ghys, Jeannette; Santran, Véronique; Bordère, Julie; Pipy, Bernard; Bernad, José; Drouet, Christophe

2012-02-14

Nanocrystalline calcium phosphate apatites constitute the mineral part of hard tissues, and the synthesis of biomimetic analogs is now well-mastered at the lab-scale. Recent advances in the fine physico-chemical characterization of these phases enable one to envision original applications in the medical field along with a better understanding of the underlying chemistry and related pharmacological features. In this contribution, we specifically focused on applications of biomimetic apatites in the field of cancer diagnosis or treatment. We first report on the production and first biological evaluations (cytotoxicity, pro-inflammatory potential, internalization by ZR-75-1 breast cancer cells) of individualized luminescent nanoparticles based on Eu-doped apatites, eventually associated with folic acid, for medical imaging purposes. We then detail, in a first approach, the preparation of tridimensional constructs associating nanocrystalline apatite aqueous gels and drug-loaded pectin microspheres. Sustained releases of a fluorescein analog (erythrosin) used as model molecule were obtained over 7 days, in comparison with the ceramic or microsphere reference compounds. Such systems could constitute original bone-filling materials for in situ delivery of anticancer drugs. Copyright © 2011 Elsevier B.V. All rights reserved.

Biomimetic structured surfaces increase primary adhesion capacity of cartilage implants.

PubMed

Lahner, Matthias; Kalwa, Lukas; Olbring, Roxana; Mohr, Charlotte; Göpfert, Lena; Seidl, Tobias

2015-01-01

In cartilage repair, scaffold-assisted single-step techniques are used to improve the cartilage regeneration. Nevertheless, the fixation of cartilage implants represents a challenge in orthopaedics, particularly in the moist conditions that pertain during arthroscopic surgery. Within the animal kingdom a broad range of species has developed working solutions to intermittent adhesion under challenging conditions. Using a top-down approach we identified promising mechanisms for biomimetic transfer The tree-frog adhesive system served as a test case to analyze the adhesion capacity of a polyglycolic acid (PGA) scaffold with and without a structural modification in a bovine articular cartilage defect model. To this end, PGA implants were modified with a simplified foot-pad structure and evaluated on femoral articular bovine cartilage lesions. Non-structured PGA scaffolds were used as control. Both implants were pressed on 20 mm × 20 mm full-thickness femoral cartilage defects using a dynamometer. The structured scaffolds showed a higher adhesion capacity on the cartilage defect than the non-structured original scaffolds. The results suggest that the adhesion ability can be increased by means of biomimetic structured surfaces without the need of additional chemical treatment and thus significantly facilitate primary fixation procedures.

A Chemical Phosphorylation-inspired Design for Type I Collagen Biomimetic Remineralization

PubMed Central

Gu, Li-sha; Kim, Jongryul; Kim, Young Kyung; Liu, Yan; Dickens, Sabine H.; Pashley, David H.; Ling, Jun-qi; Tay, Franklin R.

2010-01-01

Objectives Type I collagen alone cannot initiate tissue mineralization. Sodium trimetaphosphate (STMP) is frequently employed as a chemical phosphorylating reagent in the food industry. This study examined the feasibility of using STMP as a functional analog of matrix phosphoproteins for biomimetic remineralization of resin-bonded dentin. Methods Equilibrium adsorption and desorption studies of STMP were performed using demineralized dentin powder (DDP). Interaction between STMP and DDP was examined using Fourier-transform infrared spectroscopy. Based on those results, a bio-inspired mineralization scheme was developed for chemical phosphorylation of acid-etched dentin with STMP, followed by infiltration of the STMP-treated collagen matrix with two etch-and-rinse adhesives. Resin-dentin interfaces were remineralized in a Portland cement-simulated body fluid system, with or without the use of polyacrylic acid (PAA) as a dual biomimetic analog. Remineralized resin-dentin interfaces were examined unstained using transmission electron microscopy. Results Analysis of saturation binding curves revealed the presence of irreversible phosphate group binding sites on the surface of the DDP. FT-IR provided additional evidence of chemical interaction between STMP and DDP, with increased in the peak intensities of the P=O and P–O–C stretching modes. Those peaks returned to their original intensities after alkaline phosphatase treatment. Evidence of intrafibrillar apatite formation could be seen in incompletely resin-infiltrated, STMP-phosphorylated collagen matrices only when PAA was present in the SBF. Significance These results reinforce the importance of PAA for sequestration of amorphous calcium phosphate nanoprecursors in the biomimetic remineralization scheme. They also highlight the role of STMP as a templating analog of dentin matrix phosphoproteins for inducing intrafibrillar remineralization of apatite nanocrystals within the collagen matrix of incompletely resin

VEGF-incorporated biomimetic poly(lactide-co-glycolide) sintered microsphere scaffolds for bone tissue engineering.

PubMed

Jabbarzadeh, Ehsan; Deng, Meng; Lv, Qing; Jiang, Tao; Khan, Yusuf M; Nair, Lakshmi S; Laurencin, Cato T

2012-11-01

Regenerative engineering approaches utilizing biomimetic synthetic scaffolds provide alternative strategies to repair and restore damaged bone. The efficacy of the scaffolds for functional bone regeneration critically depends on their ability to induce and support vascular infiltration. In the present study, three-dimensional (3D) biomimetic poly(lactide-co-glycolide) (PLAGA) sintered microsphere scaffolds were developed by sintering together PLAGA microspheres followed by nucleation of minerals in a simulated body fluid. Further, the angiogenic potential of vascular endothelial growth factor (VEGF)-incorporated mineralized PLAGA scaffolds were examined by monitoring the growth and phenotypic expression of endothelial cells on scaffolds. Scanning electron microscopy micrographs confirmed the growth of bone-like mineral layers on the surface of microspheres. The mineralized PLAGA scaffolds possessed interconnectivity and a compressive modulus of 402 ± 61 MPa and compressive strength of 14.6 ± 2.9 MPa. Mineralized scaffolds supported the attachment and growth and normal phenotypic expression of endothelial cells. Further, precipitation of apatite layer on PLAGA scaffolds resulted in an enhanced VEGF adsorption and prolonged release compared to nonmineralized PLAGA and, thus, a significant increase in endothelial cell proliferation. Together, these results demonstrated the potential of VEGF-incorporated biomimetic PLAGA sintered microsphere scaffolds for bone tissue engineering as they possess the combined effects of osteointegrativity and angiogenesis. Copyright © 2012 Wiley Periodicals, Inc.

Fabrication and characterization of biomimetic multichanneled crosslinked-urethane-doped polyester tissue engineered nerve guides.

PubMed

Tran, Richard T; Choy, Wai Man; Cao, Hung; Qattan, Ibrahim; Chiao, Jung-Chih; Ip, Wing Yuk; Yeung, Kelvin Wai Kwok; Yang, Jian

2014-08-01

Biomimetic scaffolds that replicate the native architecture and mechanical properties of target tissues have been recently shown to be a very promising strategy to guide cellular growth and facilitate tissue regeneration. In this study, porous, soft, and elastic crosslinked urethane-doped polyester (CUPE) tissue engineered nerve guides were fabricated with multiple longitudinally oriented channels and an external non-porous sheath to mimic the native endoneurial microtubular and epineurium structure, respectively. The fabrication technique described herein is highly adaptable and allows for fine control over the resulting nerve guide architecture in terms of channel number, channel diameter, porosity, and mechanical properties. Biomimetic multichanneled CUPE guides were fabricated with various channel numbers and displayed an ultimate peak stress of 1.38 ± 0.22 MPa with a corresponding elongation at break of 122.76 ± 42.17%, which were comparable to that of native nerve tissue. The CUPE nerve guides were also evaluated in vivo for the repair of a 1 cm rat sciatic nerve defect. Although histological evaluations revealed collapse of the inner structure from CUPE TENGs, the CUPE nerve guides displayed fiber populations and densities comparable with nerve autograft controls after 8 weeks of implantation. These studies are the first report of a CUPE-based biomimetic multichanneled nerve guide and warrant future studies towards optimization of the channel geometry for use in neural tissue engineering. © 2013 Wiley Periodicals, Inc.

Biomimetic photo-actuation: sensing, control and actuation in sun-tracking plants.

PubMed

Dicker, M P M; Rossiter, J M; Bond, I P; Weaver, P M

2014-09-01

Although the actuation mechanisms that drive plant movement have been investigated from a biomimetic perspective, few studies have looked at the wider sensing and control systems that regulate this motion. This paper examines photo-actuation-actuation induced by, and controlled with light-through a review of the sun-tracking functions of the Cornish Mallow. The sun-tracking movement of the Cornish Mallow leaf results from an extraordinarily complex-yet extremely elegant-process of signal perception, generation, filtering and control. Inspired by this process, a concept for a simplified biomimetic analogue of this leaf is proposed: a multifunctional structure employing chemical sensing, signal transmission, and control of composite hydrogel actuators. We present this multifunctional structure, and show that the success of the concept will require improved selection of materials and structural design. This device has application in the solar-tracking of photovoltaic panels for increased energy yield. More broadly it is envisaged that the concept of chemical sensing and control can be expanded beyond photo-actuation to many other stimuli, resulting in new classes of robust solid-state devices.

Oxidative and photoxidative polymerization of humic suprastructures by heterogeneous biomimetic catalysis.

PubMed

Nuzzo, Assunta; Piccolo, Alessandro

2013-05-13

The meso-tetra(2,6-dichloro-3-sulfonatophenyl)porphyrinate of manganese(III) chloride [Mn-(TDCPPS)Cl] biomimetic catalyst immobilized on spacer-functionalized kaolinite clay mineral was employed in the oxidative coupling reaction of a dissolved humic acid (HA) suprastructure with either chemical (H2O2) or UV-light oxidation. The changes in molecular size of humic matter subjected to catalyzed oxidative reaction were followed by high-performance size exclusion chromatography (HPSEC) with UV-vis and refractive index (RI) detectors in series, and by thermogravimetric (TGA) analysis. Both the enhanced molecular size shown by differences between HPSEC chromatograms of humic reaction mixtures at either pH 6 or 3.5 and the increase of thermogravimetric stability suggest that the heterogeneous biomimetic catalysis promoted the stabilization of humic conformations by new intermolecular covalent bonds during oxidative coupling. The similarity between chemical and light-induced oxidation results suggests potential multiple applications of the kaolinite-supported heterogeneous catalyst in controlling the reactivity of natural organic matter within biogeochemical cycles and environmental reactions.

Biomimetic small scale variable focal length lens unit using synthetic elastomer actuators

NASA Astrophysics Data System (ADS)

Kim, Baek-chul; Chung, Jinah; Lee, Y.; Nam, Jae-Do; Moon, Hyungpil; Choi, Hyouk Ryeol; Koo, J. C.

2011-04-01

Having a combination of a gel-like soft lens, ligaments, and the Ciliary muscles, the human eyes are effectively working for various focal lengths without a complicated group of lens. The simple and compact but effective optical system should deserve numerous attentions from various technical field especially portable information technology device industry. Noting the limited physical space of those deivces, demanding shock durability, and massive volume productivity, the present paper proposes a biomimetic optical lens unit that is organized with a circular silicone lens and an annular dielectric polymer actuator. Unlike the traditional optical lens mechanism that normally acquires a focus by changing its focal distance with moving lens or focal plane. the proposed optical system changes its lens thickness using a annulary connected polymer actuator in order to get image focuses. The proposed biomimetic lens system ensures high shock durability, compact physical dimensions, fast actuations, simple manufacturing process, and low production cost.

Large-Deformation Curling Actuators Based on Carbon Nanotube Composite: Advanced-Structure Design and Biomimetic Application.

PubMed

Chen, Luzhuo; Weng, Mingcen; Zhou, Zhiwei; Zhou, Yi; Zhang, Lingling; Li, Jiaxin; Huang, Zhigao; Zhang, Wei; Liu, Changhong; Fan, Shoushan

2015-12-22

In recent years, electroactive polymers have been developed as actuator materials. As an important branch of electroactive polymers, electrothermal actuators (ETAs) demonstrate potential applications in the fields of artificial muscles, biomimetic devices, robotics, and so on. Large-shape deformation, low-voltage-driven actuation, and ultrafast fabrication are critical to the development of ETA. However, a simultaneous optimization of all of these advantages has not been realized yet. Practical biomimetic applications are also rare. In this work, we introduce an ultrafast approach to fabricate a curling actuator based on a newly designed carbon nanotube and polymer composite, which completely realizes all of the above required advantages. The actuator shows an ultralarge curling actuation with a curvature greater than 1.0 cm(-1) and bending angle larger than 360°, even curling into a tubular structure. The driving voltage is down to a low voltage of 5 V. The remarkable actuation is attributed not only to the mismatch in the coefficients of thermal expansion but also to the mechanical property changes of materials during temperature change. We also construct an S-shape actuator to show the possibility of building advanced-structure actuators. A weightlifting walking robot is further designed that exhibits a fast-moving motion while lifting a sample heavier than itself, demonstrating promising biomimetic applications.

Clinical observation of biomimetic mineralized collagen artificial bone putty for bone reconstruction of calcaneus fracture

PubMed Central

Pan, Yong-Xiong; Yang, Guang-Gang; Li, Zhong-Wan; Shi, Zhong-Min; Sun, Zhan-Dong

2018-01-01

Abstract This study investigated clinical outcomes of biomimetic mineralized collagen artificial bone putty for bone reconstruction in the treatment of calcaneus fracture. Sixty cases of calcaneal fractures surgically treated with open reduction and internal fixation in our hospital from June 2014–2015 were chosen and randomly divided into two groups, including 30 cases treated with biomimetic mineralized collagen artificial bone putty as treatment group, and 30 cases treated with autogenous ilia as control group. The average follow-up time was 17.2 ± 3.0 months. The results showed that the surgery duration and postoperative drainage volume of treatment group were significantly lower than control group; there were no statistically significant differences in the fracture healing time, American Orthopaedic Foot and Ankle Society scores at 3 and 12 months after surgery, Böhler’s angle, Gissane’s angle and height of calcaneus between the two groups. There were no significant differences in wound complication and reject reaction between the two groups, while significant difference in donor site complication. As a conclusion, the implantation of biomimetic mineralized collagen artificial bone putty in the open reduction of calcaneal fracture resulted in reliable effect and less complications, which is suitable for clinical applications in the treatment of bone defect in calcaneal fractures. PMID:29644087

Laparoscopic Repair of Inguinal Hernia with Biomimetic Matrix

PubMed Central

2012-01-01

Background and Objectives: Materials utilized for the repair of hernias fall into 2 broad categories, synthetics and biologics. Each has its merits and drawbacks. The synthetics have a permanent, inherent strength but are associated with some incidence of chronic pain. The biologics rely on variable tissue regeneration to give strength to the repair, limiting their use to specific situations. However, thanks to their transient presence and tissue ingrowth, the biologics do not result in a significant incidence of chronic pain. We studied the use of a biomimetic (REVIVE, Biomerix Corporation, Fremont, CA) in this setting in an attempt to obviate the disadvantages of each material. Methods: Fourteen patients underwent laparoscopic repair by totally extraperitoneal and transabdominal preperitoneal techniques of 16 inguinal hernias. Follow-up was as long as 19 mo, and 8 patients were followed for > 12 mo. There were no recurrences and a 5% incidence of functionally insignificant discomfort. Results: REVIVE is shown in histology and in vivo to demonstrate regeneration and tissue ingrowth into the polycarbonate/polyuria matrix similar to that in the biologics rather than scarring or encapsulation. There were no recurrences, indicating its strength and resilience as a permanent repair similar to that in the synthetics. Conclusion: This is proof of the concept that a biomimetic may bridge the gap between the biologics and synthetics and may be able to be utilized on a regular basis with the benefits of both materials and without their drawbacks. PMID:23484565

Molecular biomimetics: nanotechnology through biology.

PubMed

Sarikaya, Mehmet; Tamerler, Candan; Jen, Alex K-Y; Schulten, Klaus; Baneyx, François

2003-09-01

Proteins, through their unique and specific interactions with other macromolecules and inorganics, control structures and functions of all biological hard and soft tissues in organisms. Molecular biomimetics is an emerging field in which hybrid technologies are developed by using the tools of molecular biology and nanotechnology. Taking lessons from biology, polypeptides can now be genetically engineered to specifically bind to selected inorganic compounds for applications in nano- and biotechnology. This review discusses combinatorial biological protocols, that is, bacterial cell surface and phage-display technologies, in the selection of short sequences that have affinity to (noble) metals, semiconducting oxides and other technological compounds. These genetically engineered proteins for inorganics (GEPIs) can be used in the assembly of functional nanostructures. Based on the three fundamental principles of molecular recognition, self-assembly and DNA manipulation, we highlight successful uses of GEPI in nanotechnology.

Enhanced Stability of the Fe(II)/Mn(II) State in a Synthetic Model of Heterobimetallic Cofactor Assembly.

PubMed

Kerber, William D; Goheen, Joshua T; Perez, Kaitlyn A; Siegler, Maxime A

2016-01-19

Heterobimetallic Mn/Fe cofactors are found in the R2 subunit of class Ic ribonucleotide reductases (R2c) and R2-like ligand binding oxidases (R2lox). Selective cofactor assembly is due at least in part to the thermodynamics of M(II) binding to the apoprotein. We report here equilibrium studies of Fe(II)/Mn(II) discrimination in the biomimetic model system H5(F-HXTA) (5-fluoro-2-hydroxy-1,3-xylene-α,α'-diamine-N,N,N',N'-tetraacetic acid). The homobimetallic F-HXTA complexes [Fe(H2O)6][1]2·14H2O and [Mn(H2O)6][2]2·14H2O (1 = [Fe(II)2(F-HXTA)(H2O)4](-); 2 = [Mn(II)2(F-HXTA)(H2O)4](-)) were characterized by single crystal X-ray diffraction. NMR data show that 1 retains its structure in solution (2 is NMR silent). Metal exchange is facile, and the heterobimetallic complex [Fe(II)Mn(II)(F-HXTA)(H2O)4](-) (3) is formed from mixtures of 1 and 2. (19)F NMR was used to quantify 1 and 3 in the presence of excess M(II)(aq) at various metal ratios, and equilibrium constants for Fe(II)/Mn(II) discrimination were calculated from these data. Fe(II) is preferred over Mn(II) with K1 = 182 ± 13 for complete replacement (2 ⇌ 1). This relatively modest preference is attributed to a hard-soft acid-base mismatch between the divalent cations and the polycarboxylate ligand. The stepwise constants for replacement are K2 = 20.1 ± 1.3 (2 ⇌ 3) and K3 = 9.1 ± 1.1 (3 ⇌ 1). K2 > K3 demonstrates enhanced stability of the heterobimetallic state beyond what is expected for simple Mn(II) → Fe(II) replacement. The relevance to Fe(II)/Mn(II) discrimination in R2c and R2lox proteins is discussed.

Novel 3D Tissue Engineered Bone Model, Biomimetic Nanomaterials, and Cold Atmospheric Plasma Technique for Biomedical Applications

NASA Astrophysics Data System (ADS)

Wang, Mian

This thesis research is consist of four chapters, including biomimetic three-dimensional tissue engineered nanostructured bone model for breast cancer bone metastasis study (Chapter one), cold atmospheric plasma for selectively ablating metastatic breast cancer (Chapter two), design of biomimetic and bioactive cold plasma modified nanostructured scaffolds for enhanced osteogenic differentiation of bone marrow derived mesenchymal stem cells (Chapter three), and enhanced osteoblast and mesenchymal stem cell functions on titanium with hydrothermally treated nanocrystalline hydroxyapatite/magnetically treated carbon nanotubes for orthopedic applications (Chapter four). All the thesis research is focused on nanomaterials and the use of cold plasma technique for various biomedical applications.

Engineering biomimetic periosteum with β-TCP scaffolds to promote bone formation in calvarial defects of rats.

PubMed

Zhang, Dan; Gao, Peng; Li, Qin; Li, Jinda; Li, Xiaojuan; Liu, Xiaoning; Kang, Yunqing; Ren, Liling

2017-06-05

There is a critical need for the management of large bone defects. The purpose of this study was to engineer a biomimetic periosteum and to combine this with a macroporous β-tricalcium phosphate (β-TCP) scaffold for bone tissue regeneration. Rat bone marrow-derived mesenchymal stem cells (rBMSCs) were harvested and cultured in different culture media to form undifferentiated rBMSC sheets (undifferentiated medium (UM)) and osteogenic cell sheets (osteogenic medium (OM)). Simultaneously, rBMSCs were differentiated to induced endothelial-like cells (iECs), and the iECs were further cultured on a UM to form a vascularized cell sheet. At the same time, flow cytometry was used to detect the conversion rates of rBMSCs to iECs. The pre-vascularized cell sheet (iECs/UM) and the osteogenic cell sheet (OM) were stacked together to form a biomimetic periosteum with two distinct layers, which mimicked the fibrous layer and cambium layer of native periosteum. The biomimetic periostea were wrapped onto porous β-TCP scaffolds (BP/β-TCP) and implanted in the calvarial bone defects of rats. As controls, autologous periostea with β-TCP (AP/β-TCP) and β-TCP alone were implanted in the calvarial defects of rats, with a no implantation group as another control. At 2, 4, and 8 weeks post-surgery, implants were retrieved and X-ray, microcomputed tomography (micro-CT), histology, and immunohistochemistry staining analyses were performed. Flow cytometry results showed that rBMSCs were partially differentiated into iECs with a 35.1% conversion rate in terms of CD31. There were still 20.97% rBMSCs expressing CD90. Scanning electron microscopy (SEM) results indicated that cells from the wrapped cell sheet on the β-TCP scaffold apparently migrated into the pores of the β-TCP scaffold. The histology and immunohistochemistry staining results from in vivo implantation indicated that the BP/β-TCP and AP/β-TCP groups promoted the formation of blood vessels and new bone tissues in the bone

Na⁺ and K⁺ ion selectivity by size-controlled biomimetic graphene nanopores.

PubMed

Kang, Yu; Zhang, Zhisen; Shi, Hui; Zhang, Junqiao; Liang, Lijun; Wang, Qi; Ågren, Hans; Tu, Yaoquan

2014-09-21

Because biological ionic channels play a key role in cellular transport phenomena, they have attracted extensive research interest for the design of biomimetic nanopores with high permeability and selectivity in a variety of technical applications. Inspired by the structure of K(+) channel proteins, we designed a series of oxygen doped graphene nanopores of different sizes by molecular dynamics simulations to discriminate between K(+) and Na(+) channel transport. The results from free energy calculations indicate that the ion selectivity of such biomimetic graphene nanopores can be simply controlled by the size of the nanopore; compared to K(+), the smaller radius of Na(+) leads to a significantly higher free energy barrier in the nanopore of a certain size. Our results suggest that graphene nanopores with a distance of about 3.9 Å between two neighboring oxygen atoms could constitute a promising candidate to obtain excellent ion selectivity for Na(+) and K(+) ions.

Biomimetic synthesis and antiproliferative properties of racemic natural(-) and unnnatural(+) glyceollin I

USDA-ARS?s Scientific Manuscript database

A 14-step biomimetic synthetic route to glyceollin I in ca. 1.5% overall yield has been developed. In addition to being useful for the elaboration of analogs that can contribute to SAR, this route provides practical access to analytical standards that may be used for quality control purposes when gl...

Biomimetics inspired surfaces for drag reduction and oleophobicity/philicity

PubMed Central

2011-01-01

Summary The emerging field of biomimetics allows one to mimic biology or nature to develop nanomaterials, nanodevices, and processes which provide desirable properties. Hierarchical structures with dimensions of features ranging from the macroscale to the nanoscale are extremely common in nature and possess properties of interest. There are a large number of objects including bacteria, plants, land and aquatic animals, and seashells with properties of commercial interest. Certain plant leaves, such as lotus (Nelumbo nucifera) leaves, are known to be superhydrophobic and self-cleaning due to the hierarchical surface roughness and presence of a wax layer. In addition to a self-cleaning effect, these surfaces with a high contact angle and low contact angle hysteresis also exhibit low adhesion and drag reduction for fluid flow. An aquatic animal, such as a shark, is another model from nature for the reduction of drag in fluid flow. The artificial surfaces inspired from the shark skin and lotus leaf have been created, and in this article the influence of structure on drag reduction efficiency is reviewed. Biomimetic-inspired oleophobic surfaces can be used to prevent contamination of the underwater parts of ships by biological and organic contaminants, including oil. The article also reviews the wetting behavior of oil droplets on various superoleophobic surfaces created in the lab. PMID:21977417

Optimization of a biomimetic bone cement: role of DCPD.

PubMed

Panzavolta, Silvia; Bracci, Barbara; Rubini, Katia; Bigi, Adriana

2011-08-01

We previously proposed a biomimetic α-tricalcium phosphate (α-TCP) bone cement where gelatin controls the transformation of α-TCP into calcium deficient hydroxyapatite (CDHA), leading to improved mechanical properties. In this study we investigated the setting and hardening processes of biomimetic cements containing increasing amounts of CaHPO(4)·2H2O (DCPD) (0, 2.5, 5, 10, 15 wt.%), with the aim to optimize composition. Both initial and final setting times increased significantly when DCPD content accounts for 10 wt.%, whereas cements containing 15 wt.% DCPD did not set at all. Differential scanning calorimetry (DSC), X-ray diffraction (XRD), thermogravimetry (TG) and scanning electron microscopy (SEM) investigations were performed on samples maintained in physiological solution for different times. DCPD dissolution starts soon after cement preparation, but the rate of transformation decreases on increasing DCPD initial content in the samples. The rate of α-TCP to CDHA conversion during hardening decreases on increasing DCPD initial content. Moreover, the presence of DCPD prevents gelatin release during hardening. The combined effects of gelatin and DCPD on the rate of CDHA formation and porosity lead to significantly improved mechanical properties, with the best composition displaying a compressive strength of 35 MPa and a Young modulus of 1600 MPa. Copyright © 2011 Elsevier Inc. All rights reserved.

Biomimetic molecular design tools that learn, evolve, and adapt

PubMed Central

2017-01-01

A dominant hallmark of living systems is their ability to adapt to changes in the environment by learning and evolving. Nature does this so superbly that intensive research efforts are now attempting to mimic biological processes. Initially this biomimicry involved developing synthetic methods to generate complex bioactive natural products. Recent work is attempting to understand how molecular machines operate so their principles can be copied, and learning how to employ biomimetic evolution and learning methods to solve complex problems in science, medicine and engineering. Automation, robotics, artificial intelligence, and evolutionary algorithms are now converging to generate what might broadly be called in silico-based adaptive evolution of materials. These methods are being applied to organic chemistry to systematize reactions, create synthesis robots to carry out unit operations, and to devise closed loop flow self-optimizing chemical synthesis systems. Most scientific innovations and technologies pass through the well-known “S curve”, with slow beginning, an almost exponential growth in capability, and a stable applications period. Adaptive, evolving, machine learning-based molecular design and optimization methods are approaching the period of very rapid growth and their impact is already being described as potentially disruptive. This paper describes new developments in biomimetic adaptive, evolving, learning computational molecular design methods and their potential impacts in chemistry, engineering, and medicine. PMID:28694872

Polar Nature of Biomimetic Fluorapatite/Gelatin Composites: A Comparison of Bipolar Objects and the Polar State of Natural Tissue.

PubMed

Burgener, Matthias; Putzeys, Tristan; Gashti, Mazeyar Parvinzadeh; Busch, Susanne; Aboulfadl, Hanane; Wübbenhorst, Michael; Kniep, Rüdiger; Hulliger, Jürg

2015-09-14

The correspondence of the state of alignment of macromolecules in biomimetic materials and natural tissues is demonstrated by investigating a mechanism of electrical polarity formation: An in vitro grown biomimetic FAp/gelatin composite is investigated for its polar properties by second harmonic (SHGM) and scanning pyroelectric microscopy (SPEM). Hexagonal prismatic seed crystals formed in gelatin gels represent a monodomain polar state, due to aligned mineralized gelatin molecules. Later growth stages, showing dumbbell morphologies, develop into a bipolar state because of surface recognition by gelatin functionality: A reversal of the polar alignment of macromolecules, thus, takes place close to that basal plane of the seed. In natural hard tissues (teeth and bone investigated by SPEM) and the biomimetic FAp/gelatin composite, we find a surprising analogy in view of growth-induced states of polarity: The development of polarity in vivo and in vitro can be explained by a Markov-type mechanism of molecular recognition during the attachment of macromolecules.

Electrospun biomimetic scaffold of hydroxyapatite/chitosan supports enhanced osteogenic differentiation of mMSCs

NASA Astrophysics Data System (ADS)

Peng, Hongju; Yin, Zi; Liu, Huanhuan; Chen, Xiao; Feng, Bei; Yuan, Huihua; Su, Bo; Ouyang, Hongwei; Zhang, Yanzhong

2012-12-01

Engaging functional biomaterial scaffolds to regulate stem cell differentiation has drawn a great deal of attention in the tissue engineering and regenerative medicine community. In this study, biomimetic composite nanofibrous scaffolds of hydroxyapatite/chitosan (HAp/CTS) were prepared to investigate their capacity for inducing murine mesenchymal stem cells (mMSCs) to differentiate into the osteogenic lineage, in the absence and presence of an osteogenic supplementation (i.e., ascorbic acid, β-glycerol phosphate, and dexamethasone), respectively. Using electrospun chitosan (CTS) nanofibrous scaffolds as the control, cell morphology, growth, specific osteogenic genes expression, and quantified proteins secretion on the HAp/CTS scaffolds were sequentially examined and assessed. It appeared that the HAp/CTS scaffolds supported better attachment and proliferation of the mMSCs. Most noteworthy was that in the absence of the osteogenic supplementation, expression of osteogenic genes including collagen I (Col I), runt-related transcription factor 2 (Runx2), alkaline phosphatase (ALP), and osteocalcin (OCN) were significantly upregulated in mMSCs cultured on the HAp/CTS nanofibrous scaffolds. Also increased secretion of the osteogenesis protein markers of alkaline phosphatase and collagen confirmed that the HAp/CTS nanofibrous scaffold markedly promoted the osteogenic commitment in the mMSCs. Moreover, the presence of osteogenic supplementation proved an enhanced efficacy of mMSC osteogenesis on the HAp/CTS nanofibrous scaffolds. Collectively, this study demonstrated that the biomimetic nanofibrous HAp/CTS scaffolds could support and enhance the adhesion, proliferation, and particularly osteogenic differentiation of the mMSCs. It also substantiated the potential of using biomimetic nanofibrous scaffolds of HAp/CTS for functional bone repair and regeneration applications.

Biomimetic "Cactus Spine" with Hierarchical Groove Structure for Efficient Fog Collection.

PubMed

Bai, Fan; Wu, Juntao; Gong, Guangming; Guo, Lin

2015-07-01

A biomimetic "cactus spine" with hierarchical groove structure is designed and fabricated using simple electrospinning. This novel artificial cactus spine possesses excellent fog collection and water transportation ability. A model cactus equipped with artificial spines also shows a great water storage capacity. The results can be helpful in the development of water collectors and may make a contribution to the world water crisis.

Biomimetic polyesters and their role in ion transport across cell membranes.

PubMed

Jedliński, Z; Kurcok, P; Adamus, G; Juzwa, M

2000-01-01

Syntheses of biomimetic low-molecular weight poly-(R)-3-hydroxybutanoate mediated by three types of supramolecular catalysts are presented. The utility of these synthetic polyesters for preparation of artificial channels in phospholipid bilayers capable of sodium and calcium ion transport across cell membranes, is discussed. Further studies on possible applications of these bio-polymers for manufacturing drugs of prolonged activity are under way.

Artificial insect wings with biomimetic wing morphology and mechanical properties.

PubMed

Liu, Zhiwei; Yan, Xiaojun; Qi, Mingjing; Zhu, Yangsheng; Huang, Dawei; Zhang, Xiaoyong; Lin, Liwei

2017-09-26

The pursuit of a high lift force for insect-scale flapping-wing micro aerial vehicles (FMAVs) requires that their artificial wings possess biomimetic wing features which are close to those of their natural counterpart. In this work, we present both fabrication and testing methods for artificial insect wings with biomimetic wing morphology and mechanical properties. The artificial cicada (Hyalessa maculaticollis) wing is fabricated through a high precision laser cutting technique and a bonding process of multilayer materials. Through controlling the shape of the wing venation, the fabrication method can achieve three-dimensional wing architecture, including cambers or corrugations. Besides the artificial cicada wing, the proposed fabrication method also shows a promising versatility for diverse wing types. Considering the artificial cicada wing's characteristics of small size and light weight, special mechanical testing systems are designed to investigate its mechanical properties. Flexural stiffness, maximum deformation rate and natural frequency are measured and compared with those of its natural counterpart. Test results reveal that the mechanical properties of the artificial cicada wing depend strongly on its vein thickness, which can be used to optimize an artificial cicada wing's mechanical properties in the future. As such, this work provides a new form of artificial insect wings which can be used in the field of insect-scale FMAVs.

Biomimetic synthesis of hierarchical crystalline hydroxyapatite fibers in large-scale

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

Xing, Chaogang; Ge, Suxiang; Huang, Baojun

Highlights: ► Crystalline hierarchical hydroxyapatite (HAp) fibers are synthesized. ► We employ a biomimetic route by using cotton cloth as a natural bio-template. ► We study the effects of pH, ultrasonic cleaning time, and calcination temperature. ► We obtain an optimized reaction condition. ► This is a low cost method for production of hierarchical HAp fibers. -- Abstract: Crystalline hierarchical hydroxyapatite [Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}, HAp)] fibers were successfully synthesized via a biomimetic route by using cotton cloth as a natural bio-template. The effects of pH value, aging time, ultrasonic cleaning time, and calcination temperature on the purity andmore » morphology of the resulting hydroxyapatite (HAp) were monitored by scanning election microscope (SEM), X-ray diffraction (XRD), and infrared spectrophotometer (IR) to obtain an optimized reaction condition, namely, pH 9, ultrasonic cleaning for 1 min, aging for 24 h, and calcination at 600 °C for 4 h. We found that the natural cellulose could not only control the morphology of HAp but also lower its phase transformation temperature. The impact of this method lies in its low cost and successful production of large-scale patterning of three-dimensional hierarchical HAp fibers.« less

Rapid prototyping of biomimetic vascular phantoms for hyperspectral reflectance imaging.

PubMed

Ghassemi, Pejhman; Wang, Jianting; Melchiorri, Anthony J; Ramella-Roman, Jessica C; Mathews, Scott A; Coburn, James C; Sorg, Brian S; Chen, Yu; Pfefer, T Joshua

2015-01-01

The emerging technique of rapid prototyping with three-dimensional (3-D) printers provides a simple yet revolutionary method for fabricating objects with arbitrary geometry. The use of 3-D printing for generating morphologically biomimetic tissue phantoms based on medical images represents a potentially major advance over existing phantom approaches. Toward the goal of image-defined phantoms, we converted a segmented fundus image of the human retina into a matrix format and edited it to achieve a geometry suitable for printing. Phantoms with vessel-simulating channels were then printed using a photoreactive resin providing biologically relevant turbidity, as determined by spectrophotometry. The morphology of printed vessels was validated by x-ray microcomputed tomography. Channels were filled with hemoglobin (Hb) solutions undergoing desaturation, and phantoms were imaged with a near-infrared hyperspectral reflectance imaging system. Additionally, a phantom was printed incorporating two disjoint vascular networks at different depths, each filled with Hb solutions at different saturation levels. Light propagation effects noted during these measurements—including the influence of vessel density and depth on Hb concentration and saturation estimates, and the effect of wavelength on vessel visualization depth—were evaluated. Overall, our findings indicated that 3-D-printed biomimetic phantoms hold significant potential as realistic and practical tools for elucidating light–tissue interactions and characterizing biophotonic system performance.

A Novel General Chemistry Laboratory: Creation of Biomimetic Superhydrophobic Surfaces through Replica Molding

ERIC Educational Resources Information Center

Verbanic, Samuel; Brady, Owen; Sanda, Ahmed; Gustafson, Carolina; Donhauser, Zachary J.

2014-01-01

Biomimetic replicas of superhydrophobic lotus and taro leaf surfaces can be made using polydimethylsiloxane. These replicas faithfully reproduce the microstructures of the leaves' surface and can be analyzed using contact angle goniometry, self-cleaning experiments, and optical microscopy. These simple and adaptable experiments were used to…

Laminin and biomimetic extracellular elasticity enhance functional differentiation in mammary epithelia

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

Alcaraz, Jordi; Xu, Ren; Mori, Hidetoshi

2008-10-20

In the mammary gland, epithelial cells are embedded in a 'soft' environment and become functionally differentiated in culture when exposed to a laminin-rich extracellular matrix gel. Here, we define the processes by which mammary epithelial cells integrate biochemical and mechanical extracellular cues to maintain their differentiated phenotype. We used single cells cultured on top of gels in conditions permissive for {beta}-casein expression using atomic force microscopy to measure the elasticity of the cells and their underlying substrata. We found that maintenance of {beta}-casein expression required both laminin signalling and a 'soft' extracellular matrix, as is the case in normal tissuesmore » in vivo, and biomimetic intracellular elasticity, as is the case in primary mammary epithelial organoids. Conversely, two hallmarks of breast cancer development, stiffening of the extracellular matrix and loss of laminin signalling, led to the loss of {beta}-casein expression and non-biomimetic intracellular elasticity. Our data indicate that tissue-specific gene expression is controlled by both the tissues unique biochemical milieu and mechanical properties, processes involved in maintenance of tissue integrity and protection against tumorigenesis.« less

Detection, recognition, identification, and tracking of military vehicles using biomimetic intelligence

NASA Astrophysics Data System (ADS)

Pace, Paul W.; Sutherland, John

2001-10-01

This project is aimed at analyzing EO/IR images to provide automatic target detection/recognition/identification (ATR/D/I) of militarily relevant land targets. An increase in performance was accomplished using a biomimetic intelligence system functioning on low-cost, commercially available processing chips. Biomimetic intelligence has demonstrated advanced capabilities in the areas of hand- printed character recognition, real-time detection/identification of multiple faces in full 3D perspectives in cluttered environments, advanced capabilities in classification of ground-based military vehicles from SAR, and real-time ATR/D/I of ground-based military vehicles from EO/IR/HRR data in cluttered environments. The investigation applied these tools to real data sets and examined the parameters such as the minimum resolution for target recognition, the effect of target size, rotation, line-of-sight changes, contrast, partial obscuring, background clutter etc. The results demonstrated a real-time ATR/D/I capability against a subset of militarily relevant land targets operating in a realistic scenario. Typical results on the initial EO/IR data indicate probabilities of correct classification of resolved targets to be greater than 95 percent.

Biomimetic engineered muscle with capacity for vascular integration and functional maturation in vivo

PubMed Central

Juhas, Mark; Engelmayr, George C.; Fontanella, Andrew N.; Palmer, Gregory M.; Bursac, Nenad

2014-01-01

Tissue-engineered skeletal muscle can serve as a physiological model of natural muscle and a potential therapeutic vehicle for rapid repair of severe muscle loss and injury. Here, we describe a platform for engineering and testing highly functional biomimetic muscle tissues with a resident satellite cell niche and capacity for robust myogenesis and self-regeneration in vitro. Using a mouse dorsal window implantation model and transduction with fluorescent intracellular calcium indicator, GCaMP3, we nondestructively monitored, in real time, vascular integration and the functional state of engineered muscle in vivo. During a 2-wk period, implanted engineered muscle exhibited a steady ingrowth of blood-perfused microvasculature along with an increase in amplitude of calcium transients and force of contraction. We also demonstrated superior structural organization, vascularization, and contractile function of fully differentiated vs. undifferentiated engineered muscle implants. The described in vitro and in vivo models of biomimetic engineered muscle represent enabling technology for novel studies of skeletal muscle function and regeneration. PMID:24706792

Biomimetic Synthesis of Gelatin Polypeptide-Assisted Noble-Metal Nanoparticles and Their Interaction Study

PubMed Central

2011-01-01

Herein, the generation of gold, silver, and silver–gold (Ag–Au) bimetallic nanoparticles was carried out in collagen (gelatin) solution. It first showed that the major ingredient in gelatin polypeptide, glutamic acid, acted as reducing agent to biomimetically synthesize noble metal nanoparticles at 80°C. The size of nanoparticles can be controlled not only by the mass ratio of gelatin to gold ion but also by pH of gelatin solution. Interaction between noble-metal nanoparticles and polypeptide has been investigated by TEM, UV–visible, fluorescence spectroscopy, and HNMR. This study testified that the degradation of gelatin protein could not alter the morphology of nanoparticles, but it made nanoparticles aggregated clusters array (opposing three-dimensional α-helix folding structure) into isolated nanoparticles stabilized by gelatin residues. This is a promising merit of gelatin to apply in the synthesis of nanoparticles. Therefore, gelatin protein is an excellent template for biomimetic synthesis of noble metal/bimetallic nanoparticle growth to form nanometer-sized device. PMID:27502645

Biomimetic Synthesis of Gelatin Polypeptide-Assisted Noble-Metal Nanoparticles and Their Interaction Study

NASA Astrophysics Data System (ADS)

Liu, Ying; Liu, Xiaoheng; Wang, Xin

2011-12-01

Herein, the generation of gold, silver, and silver-gold (Ag-Au) bimetallic nanoparticles was carried out in collagen (gelatin) solution. It first showed that the major ingredient in gelatin polypeptide, glutamic acid, acted as reducing agent to biomimetically synthesize noble metal nanoparticles at 80°C. The size of nanoparticles can be controlled not only by the mass ratio of gelatin to gold ion but also by pH of gelatin solution. Interaction between noble-metal nanoparticles and polypeptide has been investigated by TEM, UV-visible, fluorescence spectroscopy, and HNMR. This study testified that the degradation of gelatin protein could not alter the morphology of nanoparticles, but it made nanoparticles aggregated clusters array (opposing three-dimensional α-helix folding structure) into isolated nanoparticles stabilized by gelatin residues. This is a promising merit of gelatin to apply in the synthesis of nanoparticles. Therefore, gelatin protein is an excellent template for biomimetic synthesis of noble metal/bimetallic nanoparticle growth to form nanometer-sized device.

In vivo remineralization of dentin using an agarose hydrogel biomimetic mineralization system

NASA Astrophysics Data System (ADS)

Han, Min; Li, Quan-Li; Cao, Ying; Fang, Hui; Xia, Rong; Zhang, Zhi-Hong

2017-02-01

A novel agarose hydrogel biomimetic mineralization system loaded with calcium and phosphate was used to remineralize dentin and induce the oriented densely parallel packed HA layer on defective dentin surface in vivo in a rabbit model. Firstly, the enamel of the labial surface of rabbits’ incisor was removed and the dentin was exposed to oral environment. Secondly, the hydrogel biomimetic mineralization system was applied to the exposed dentin surface by using a custom tray. Finally, the teeth were extracted and evaluated by scanning electron microscopy, X-ray diffraction, and nanoindentation test after a certain time of mineralization intervals. The regenerated tissue on the dentin surface was composed of highly organised HA crystals. Densely packed along the c axis, these newly precipitated HA crystals were perpendicular to the underlying dental surface with a tight bond. The demineralized dentin was remineralized and dentinal tubules were occluded by the grown HA crystals. The nanohardness and elastic modulus of the regenerated tissue were similar to natural dentin. The results indicated a potential clinical use for repairing dentin-exposed related diseases, such as erosion, wear, and dentin hypersensitivity.

Biomimetic oral mucin from polymer micelle networks

NASA Astrophysics Data System (ADS)

Authimoolam, Sundar Prasanth

Mucin networks are formed by the complexation of bottlebrush-like mucin glycoprotein with other small molecule glycoproteins. These glycoproteins create nanoscale strands that then arrange into a nanoporous mesh. These networks play an important role in ensuring surface hydration, lubricity and barrier protection. In order to understand the functional behavior in mucin networks, it is important to decouple their chemical and physical effects responsible for generating the fundamental property-function relationship. To achieve this goal, we propose to develop a synthetic biomimetic mucin using a layer-by-layer (LBL) deposition approach. In this work, a hierarchical 3-dimensional structures resembling natural mucin networks was generated using affinity-based interactions on synthetic and biological surfaces. Unlike conventional polyelectrolyte-based LBL methods, pre-assembled biotin-functionalized filamentous (worm-like) micelles was utilized as the network building block, which from complementary additions of streptavidin generated synthetic networks of desired thickness. The biomimetic nature in those synthetic networks are studied by evaluating its structural and bio-functional properties. Structurally, synthetic networks formed a nanoporous mesh. The networks demonstrated excellent surface hydration property and were able capable of microbial capture. Those functional properties are akin to that of natural mucin networks. Further, the role of synthetic mucin as a drug delivery vehicle, capable of providing localized and tunable release was demonstrated. By incorporating antibacterial curcumin drug loading within synthetic networks, bacterial growth inhibition was also demonstrated. Thus, such bioactive interfaces can serve as a model for independently characterizing mucin network properties and through its role as a drug carrier vehicle it presents exciting future opportunities for localized drug delivery, in regenerative applications and as bio

(Cryptand-222)potassium(+) (hydrogensulfido)[5,10,15,20-tetra-kis(2-pival-amido-phen-yl)porphyrinato]ferrate(II).

PubMed

Dhifet, Mondher; Belkhiria, Mohamed Salah; Daran, Jean-Claude; Nasri, Habib

2009-07-22

As part of a systematic investigation for a number of Fe(II) porphyrin complexes used as biomimetic models for cytochrome P450, crystals of the title compound, [K(C(18)H(36)N(2)O(6))][Fe(II)(C(64)H(64)N(8)O(4))(HS)], were prepared. The compound exhibits a non-planar conformation with major ruffling and saddling distortions. The average equatorial iron-pyrrole N atom [Fe-N(p) = 2.102 (2) Å] bond length and the distance between the Fe(II) atom and the 24-atom core of the porphyrin ring (Fe-P(C)= 0.558 Å) are typical for high-spin iron(II) penta-coordinate porphyrinates. One of the tert-butyl groups in the structure is disordered over two sets with occupancies of 0.84 and 0.16.

Interactions between meniscal cells and a self assembled biomimetic surface composed of hyaluronic acid, chitosan and meniscal extracellular matrix molecules.

PubMed

Tan, Guak-Kim; Dinnes, Donna L M; Butler, Lauren N; Cooper-White, Justin J

2010-08-01

Menisci are one of the most commonly injured parts of the knee with a limited healing potential. This study focuses on fabrication and characterization of biomimetic surfaces for meniscal tissue engineering. To achieve this, a combination of hyaluronic acid/chitosan (HA/CH) mutilayers with covalently immobilized major extracellular matrix (ECM) components of native meniscus, namely collagen I/II (COL.I/II) and chondroitin-6-sulfate (C6S) was employed. Adsorption of the biomolecules was monitored using a quartz crystal microbalance with dissipation (QCM-D) and fourier transform-surface plasmon resonance (FT-SPR). Immobilization of the biomolecules onto HA/CH mutilayers was achieved by sequential adsorption, with optimum binding at a molar ratio of 1.4:1 (COL.I/II: C6S). After adding COL.I/II, the layers became relatively more rigid and large aggregates were evident. The effects of the modified surfaces on cell proliferation, gene expression and proteoglycan production of rat meniscal cells were examined. Quantitative real-time reverse transcriptase polymerase chain reaction (RT-qPCR) analysis showed that primary meniscal cells dedifferentiated rapidly after one passage in monolayer culture. This process could be reversed by culturing the cells on C6S surfaces, as indicated by increases in both collagen II and aggrecan gene expression, as well as proteoglycan production. Cells with abundant lipid vacuoles were evident on all the surfaces over an extended culture period. The results demonstrate the feasibility of C6S surfaces to avoid the dedifferentiation that normally occurs during monolayer expansion of meniscal cells. Crown Copyright 2010. Published by Elsevier Ltd. All rights reserved.

Biomimetic syntheses of racemic natural products.

PubMed

Zask, Arie; Ellestad, George

2018-02-01

Racemic natural products are rarely produced in plants and microorganisms and are thought to be the result of nonenzymatic, spontaneous reactions. These compounds are often highly complex with multiple contiguous chiral centers that present a challenge to organic synthesis. Formation of these racemates often occurs by cyclization reactions that can generate multiple stereocenters from achiral precursors. Biomimetic synthesis of these racemic natural products provides support for their proposed nonenzymatic spontaneous biosynthesis. These elegant syntheses also provide scalable and efficient routes to these complex natural products. Although the number of reported racemic natural products is relatively low, an isolated natural product that has a very small optical rotation has been shown to be a true racemate. Thus, the occurrence of racemic natural products could be more common than thought. © 2017 Wiley Periodicals, Inc.

Biomimetic gyroid nanostructures exceeding their natural origins.

PubMed

Gan, Zongsong; Turner, Mark D; Gu, Min

2016-05-01

Using optical two-beam lithography with improved resolution and enhanced mechanical strength, we demonstrate the replication of gyroid photonic nanostructures found in the butterfly Callophrys rubi. These artificial structures are shown to have size, controllability, and uniformity that are superior to those of their biological counterparts. In particular, the elastic Young's modulus of fabricated nanowires is enhanced by up to 20%. As such, the circular dichroism enabled by the gyroid nanostructures can operate in the near-ultraviolet wavelength region, shorter than that supported by the natural butterfly wings of C. rubi. This fabrication technique provides a unique tool for extracting three-dimensional photonic designs from nature and will aid the investigation of biomimetic nanostructures.

Biomimetic gyroid nanostructures exceeding their natural origins

PubMed Central

Gan, Zongsong; Turner, Mark D.; Gu, Min

2016-01-01

Using optical two-beam lithography with improved resolution and enhanced mechanical strength, we demonstrate the replication of gyroid photonic nanostructures found in the butterfly Callophrys rubi. These artificial structures are shown to have size, controllability, and uniformity that are superior to those of their biological counterparts. In particular, the elastic Young’s modulus of fabricated nanowires is enhanced by up to 20%. As such, the circular dichroism enabled by the gyroid nanostructures can operate in the near-ultraviolet wavelength region, shorter than that supported by the natural butterfly wings of C. rubi. This fabrication technique provides a unique tool for extracting three-dimensional photonic designs from nature and will aid the investigation of biomimetic nanostructures. PMID:27386542

Block copolymers for biomimetic composites

NASA Astrophysics Data System (ADS)

Calvert, Paul D.; Oner, Mualla; Burdon, Jeremy; Rieke, Peter C.; Farmer, Kelly

1993-07-01

Mineralized biological tissues can be regarded as composites where a fine reinforcement is laid down in a very controlled fashion within a tough polymeric matrix. Such materials include bone, antler, tooth enamel, mollusc shell, and crustacean shell. We have been exploring ways of forming similar structures by synthetic routes involving precipitation of reinforcing particles directly into a polymeric matrix. Part of this biomimetic approach requires polymer matrices which can exert a high degree of control over the mineralization process. Polymer gels have been formed from cross-linked methacrylates with various types of functionality within the gel. By incorporating calcium binding groups we have been producing gels which lead to preferential mineralization of the gel when it is incubated in a supersaturated solution of calcium oxalate or calcium carbonate. Similarly we have been incorporating silane groups within the gel in order to promote the deposition of silica in a gel body when it is immersed in a metastable solution of partly hydrolysed silicon alkoxides.

Aminofluorene-Mediated Biomimetic Domino Amination-Oxygenation of Aldehydes to Amides.

PubMed

Ghosh, Santanu; Jana, Chandan K

2016-11-18

A conceptually novel biomimetic strategy based on a domino amination-oxygenation reaction was developed for direct amidation of aldehydes under metal-free conditions employing molecular oxygen as the oxidant. 9-Aminofluorene derivatives acted as pyridoxamine-5'-phosphate equivalents for efficient, chemoselective, and operationally simple amine-transfer oxygenation reaction. Unprecedented RNH transfer involving secondary amine to produce secondary amides was achieved. In the presence of 18 O 2 , 18 O-amide was formed with excellent (95%) isotopic purity.

Imperfect hybrid layers created by an aggressive one-step self-etch adhesive in primary dentin are amendable to biomimetic remineralization in vitro

PubMed Central

Kim, Jongryul; Vaughn, Ryan M.; Gu, Lisha; Rockman, Roy A.; Arola, Dwayne D.; Schafer, Tara E.; Choi, Kyungkyu; Pashley, David H.; Tay, Franklin R.

2009-01-01

Degradation of hybrid layers created in primary dentin occurs as early as 6 months in vivo. Biomimetic remineralization utilizes “bottom-up” nanotechnology principles for interfibrillar and intrafibrillar remineralization of collagen matrices. This study examined whether imperfect hybrid layers created in primary dentin can be remineralized. Coronal dentin surfaces were prepared from extracted primary molars and bonded using Adper Prompt L-Pop and a composite. One millimeter-thick specimen slabs of the resin-dentin interface were immersed in a Portland cement-based remineralization medium that contained two biomimetic analogs to mimic the sequestration and templating functions of dentin noncollagenous proteins. Specimens were retrieved after 1–6 months. Confocal laser scanning microscopy was employed for evaluating the permeability of hybrid layers to Rhodamine B. Transmission electron microscopy was used to examine the status of remineralization within hybrid layers. Remineralization at different locations of the hybrid layers corresponded with quenching of fluorescence within similar locations of those hybrid layers. Remineralization was predominantly intrafibrillar in nature as interfibrillar spaces were filled with adhesive resin. Biomimetic remineralization of imperfect hybrid layers in primary human dentin is a potential means for preserving bond integrity. The success of the current proof-of-concept, laterally-diffusing remineralization protocol warrants development of a clinically-applicable biomimetic remineralization delivery system. PMID:19768792

Combinatorial MAPLE deposition of antimicrobial orthopedic maps fabricated from chitosan and biomimetic apatite powders.

PubMed

Visan, A; Stan, G E; Ristoscu, C; Popescu-Pelin, G; Sopronyi, M; Besleaga, C; Luculescu, C; Chifiriuc, M C; Hussien, M D; Marsan, O; Kergourlay, E; Grossin, D; Brouillet, F; Mihailescu, I N

2016-09-10

Chitosan/biomimetic apatite thin films were grown in mild conditions of temperature and pressure by Combinatorial Matrix-Assisted Pulsed Laser Evaporation on Ti, Si or glass substrates. Compositional gradients were obtained by simultaneous laser vaporization of the two distinct material targets. A KrF* excimer (λ=248nm, τFWHM=25ns) laser source was used in all experiments. The nature and surface composition of deposited materials and the spatial distribution of constituents were studied by SEM, EDS, AFM, GIXRD, FTIR, micro-Raman, and XPS. The antimicrobial efficiency of the chitosan/biomimetic apatite layers against Staphylococcus aureus and Escherichia coli strains was interrogated by viable cell count assay. The obtained thin films were XRD amorphous and exhibited a morphology characteristic to the laser deposited structures composed of nanometric round shaped grains. The surface roughness has progressively increased with chitosan concentration. FTIR, EDS and XPS analyses indicated that the composition of the BmAp-CHT C-MAPLE composite films gradually modified from pure apatite to chitosan. The bioevaluation tests indicated that S. aureus biofilm is more susceptible to the action of chitosan-rich areas of the films, whilst the E. coli biofilm proved more sensible to areas containing less chitosan. The best compromise should therefore go, in our opinion, to zones with intermediate-to-high chitosan concentration which can assure a large spectrum of antimicrobial protection concomitantly with a significant enhancement of osseointegration, favored by the presence of biomimetic hydroxyapatite. Copyright © 2016 Elsevier B.V. All rights reserved.

Research trends in biomimetic medical materials for tissue engineering: 3D bioprinting, surface modification, nano/micro-technology and clinical aspects in tissue engineering of cartilage and bone.

PubMed

Chen, Cen; Bang, Sumi; Cho, Younghak; Lee, Sahnghoon; Lee, Inseop; Zhang, ShengMin; Noh, Insup

2016-01-01

This review discusses about biomimetic medical materials for tissue engineering of bone and cartilage, after previous scientific commentary of the invitation-based, Korea-China joint symposium on biomimetic medical materials, which was held in Seoul, Korea, from October 22 to 26, 2015. The contents of this review were evolved from the presentations of that symposium. Four topics of biomimetic medical materials were discussed from different research groups here: 1) 3D bioprinting medical materials, 2) nano/micro-technology, 3) surface modification of biomaterials for their interactions with cells and 4) clinical aspects of biomaterials for cartilage focusing on cells, scaffolds and cytokines.

Effect of doping in carbon nanotubes on the viability of biomimetic chitosan-carbon nanotubes-hydroxyapatite scaffolds.

PubMed

Fonseca-García, Abril; Mota-Morales, Josué D; Quintero-Ortega, Iraís A; García-Carvajal, Zaira Y; Martínez-López, V; Ruvalcaba, Erika; Landa-Solís, Carlos; Solis, Lilia; Ibarra, Clemente; Gutiérrez, María C; Terrones, Mauricio; Sanchez, Isaac C; del Monte, Francisco; Velasquillo, María C; Luna-Bárcenas, G

2014-10-01

This work describes the preparation and characterization of biomimetic chitosan/multiwall carbon nanotubes/nano-hydroxyapatite (CTS/MWCNT/nHAp) scaffolds and their viability for bone tissue engineering applications. The cryogenic process ice segregation-induced self-assembly (ISISA) was used to fabricate 3D biomimetic CTS scaffolds. Proper combination of cryogenics, freeze-drying, nature and molecular ratio of solutes give rise to 3D porous interconnected scaffolds with clusters of nHAp distributed along the scaffold surface. The effect of doping in CNT (e.g. with oxygen and nitrogen atoms) on cell viability was tested. Under the same processing conditions, pore size was in the range of 20-150 μm and irrespective on the type of CNT. Studies on cell viability with scaffolds were carried out using human cells from periosteum biopsy. Prior to cell seeding, the immunophenotype of mesenchymal periosteum or periosteum-derived stem cells (MSCs-PCs) was characterized by flow cytometric analysis using fluorescence-activated and characteristic cell surface markers for MSCs-PCs. The characterized MSCs-PCs maintained their periosteal potential in cell cultures until the 2nd passage from primary cell culture. Thus, the biomimetic CTS/MWCNT/nHAp scaffolds demonstrated good biocompatibility and cell viability in all cases such that it can be considered as promising biomaterials for bone tissue engineering. © 2013 Wiley Periodicals, Inc.

Thermal gelation and tissue adhesion of biomimetic hydrogels

PubMed Central

Burke, Sean A; Ritter-Jones, Marsha; Lee, Bruce P; Messersmith, Phillip B

2008-01-01

Marine and freshwater mussels are notorious foulers of natural and manmade surfaces, secreting specialized protein adhesives for rapid and durable attachment to wet substrates. Given the strong and water-resistant nature of mussel adhesive proteins, significant potential exists for mimicking their adhesive characteristics in bioinspired synthetic polymer materials. An important component of these proteins is L-3,4-dihydroxylphenylalanine (DOPA), an amino acid believed to contribute to mussel glue solidification through oxidation and crosslinking reactions. Synthetic polymers containing DOPA residues have previously been shown to crosslink into hydrogels upon the introduction of oxidizing reagents. Here we introduce a strategy for stimuli responsive gel formation of mussel adhesive protein mimetic polymers. Lipid vesicles with a bilayer melting transition of 37 °C were designed from a mixture of dipalmitoyl and dimyristoyl phosphatidylcholines and exploited for the release of a sequestered oxidizing reagent upon heating from ambient to physiologic temperature. Colorimetric studies indicated that sodium-periodate-loaded liposomes released their cargo at the phase transition temperature, and when used in conjunction with a DOPA-functionalized poly(ethylene glycol) polymer gave rise to rapid solidification of a crosslinked polymer hydrogel. The tissue adhesive properties of this biomimetic system were determined by in situ thermal gelation of liposome/polymer hydrogel between two porcine dermal tissue surfaces. Bond strength measurements showed that the bond formed by the adhesive hydrogel (mean = 35.1 kPa, SD = 12.5 kPa, n = 11) was several times stronger than a fibrin glue control tested under the same conditions. The results suggest a possible use of this biomimetic strategy for repair of soft tissues. PMID:18458476

Rapid prototyping of biomimetic vascular phantoms for hyperspectral reflectance imaging

PubMed Central

Ghassemi, Pejhman; Wang, Jianting; Melchiorri, Anthony J.; Ramella-Roman, Jessica C.; Mathews, Scott A.; Coburn, James C.; Sorg, Brian S.; Chen, Yu; Joshua Pfefer, T.

2015-01-01

Abstract. The emerging technique of rapid prototyping with three-dimensional (3-D) printers provides a simple yet revolutionary method for fabricating objects with arbitrary geometry. The use of 3-D printing for generating morphologically biomimetic tissue phantoms based on medical images represents a potentially major advance over existing phantom approaches. Toward the goal of image-defined phantoms, we converted a segmented fundus image of the human retina into a matrix format and edited it to achieve a geometry suitable for printing. Phantoms with vessel-simulating channels were then printed using a photoreactive resin providing biologically relevant turbidity, as determined by spectrophotometry. The morphology of printed vessels was validated by x-ray microcomputed tomography. Channels were filled with hemoglobin (Hb) solutions undergoing desaturation, and phantoms were imaged with a near-infrared hyperspectral reflectance imaging system. Additionally, a phantom was printed incorporating two disjoint vascular networks at different depths, each filled with Hb solutions at different saturation levels. Light propagation effects noted during these measurements—including the influence of vessel density and depth on Hb concentration and saturation estimates, and the effect of wavelength on vessel visualization depth—were evaluated. Overall, our findings indicated that 3-D-printed biomimetic phantoms hold significant potential as realistic and practical tools for elucidating light–tissue interactions and characterizing biophotonic system performance. PMID:26662064

Biomimetic surface patterning for long-term transmembrane access

PubMed Central

VanDersarl, Jules J.; Renaud, Philippe

2016-01-01

Here we present a planar patch clamp chip based on biomimetic cell membrane fusion. This architecture uses nanometer length-scale surface patterning to replicate the structure and function of membrane proteins, creating a gigaohm seal between the cell and a planar electrode array. The seal is generated passively during cell spreading, without the application of a vacuum to the cell surface. This interface can enable cell-attached and whole-cell recordings that are stable to 72 hours, and generates no visible damage to the cell. The electrodes can be very small (<5 μm) and closely packed, offering a high density platform for cellular measurement. PMID:27577519

Biomimetic surface patterning for long-term transmembrane access.

PubMed

VanDersarl, Jules J; Renaud, Philippe

2016-08-31

Here we present a planar patch clamp chip based on biomimetic cell membrane fusion. This architecture uses nanometer length-scale surface patterning to replicate the structure and function of membrane proteins, creating a gigaohm seal between the cell and a planar electrode array. The seal is generated passively during cell spreading, without the application of a vacuum to the cell surface. This interface can enable cell-attached and whole-cell recordings that are stable to 72 hours, and generates no visible damage to the cell. The electrodes can be very small (<5 μm) and closely packed, offering a high density platform for cellular measurement.

Influence of different temperatures on the thermal fatigue behavior and thermal stability of hot-work tool steel processed by a biomimetic couple laser technique

NASA Astrophysics Data System (ADS)

Meng, Chao; Zhou, Hong; Zhou, Ying; Gao, Ming; Tong, Xin; Cong, Dalong; Wang, Chuanwei; Chang, Fang; Ren, Luquan

2014-04-01

Three kinds of biomimetic non-smooth shapes (spot-shape, striation-shape and reticulation-shape) were fabricated on the surface of H13 hot-work tool steel by laser. We investigated the thermal fatigue behavior of biomimetic non-smooth samples with three kinds of shapes at different thermal cycle temperature. Moreover, the evolution of microstructure, as well as the variations of hardness of laser affected area and matrix were studied and compared. The results showed that biomimetic non-smooth samples had better thermal fatigue behavior compared to the untreated samples at different thermal cycle temperatures. For a given maximal temperature, the biomimetic non-smooth sample with reticulation-shape had the optimum thermal fatigue behavior, than with striation-shape which was better than that with the spot-shape. The microstructure observations indicated that at different thermal cycle temperatures the coarsening degrees of microstructures of laser affected area were different and the microstructures of laser affected area were still finer than that of the untreated samples. Although the resistance to thermal cycling softening of laser affected area was lower than that of the untreated sample, laser affected area had higher microhardness than the untreated sample at different thermal cycle temperature.

Advanced engineering and biomimetic materials for bone repair and regeneration

NASA Astrophysics Data System (ADS)

Yang, Lei; Zhong, Chao

2013-12-01

Over the past decade, there has been tremendous progress in developing advanced biomaterials for tissue repair and regeneration. This article reviews the frontiers of this field from two closely related areas, new engineering materials for bone substitution and biomimetic mineralization for bone-like nanocomposites. Rather than providing an exhaustive overview of the literature, we focus on several representative directions. We also discuss likely future trends in these areas, including synthetic biology-enabled biomaterials design and multifunctional implant materials for bone repair and regeneration.

Effects of Laser Energies on Wear and Tensile Properties of Biomimetic 7075 Aluminum Alloy

NASA Astrophysics Data System (ADS)

Yuan, Yuhuan; Zhang, Peng; Zhao, Guoping; Gao, Yang; Tao, Lixi; Chen, Heng; Zhang, Jianlong; Zhou, Hong

2018-03-01

Inspired by the non-smooth surface of certain animals, a biomimetic coupling unit with various sizes, microstructure, and hardness was prepared on the surface of 7075 aluminum alloy. Following experimental studies were conducted to investigate the wear and tensile properties with various laser energy inputs. The results demonstrated that the non-smooth surface with biomimetic coupling units had a positive effect on both the wear resistance and tensile property of 7075 aluminum alloy. In addition, the sample with the unit fabricated by the laser energy of 420.1 J/cm2 exhibited the most significant improvement on the wear and tensile properties owing to the minimum grain size and the highest microhardness. Also, the weight loss of the sample was one-third of the untreated one's, and the yield strength, the ultimate tensile strength, and the elongation improved by 20, 20, and 34% respectively. Moreover, the mechanisms of wear and tensile properties improvement were also analyzed.

Swimming like algae: biomimetic soft artificial cilia

PubMed Central

Sareh, Sina; Rossiter, Jonathan; Conn, Andrew; Drescher, Knut; Goldstein, Raymond E.

2013-01-01

Cilia are used effectively in a wide variety of biological systems from fluid transport to thrust generation. Here, we present the design and implementation of artificial cilia, based on a biomimetic planar actuator using soft-smart materials. This actuator is modelled on the cilia movement of the alga Volvox, and represents the cilium as a piecewise constant-curvature robotic actuator that enables the subsequent direct translation of natural articulation into a multi-segment ionic polymer metal composite actuator. It is demonstrated how the combination of optimal segmentation pattern and biologically derived per-segment driving signals reproduce natural ciliary motion. The amenability of the artificial cilia to scaling is also demonstrated through the comparison of the Reynolds number achieved with that of natural cilia. PMID:23097503

Biomimetic tissue-engineered anterior cruciate ligament replacement

PubMed Central

Cooper, James A.; Sahota, Janmeet S.; Gorum, W. Jay; Carter, Janell; Doty, Stephen B.; Laurencin, Cato T.

2007-01-01

There are >200,000 anterior cruciate ligament (ACL) ruptures each year in the United States, and, due to the poor healing properties of the ACL, surgical reconstruction with autograft or allograft tissue is the current treatment of these injuries. To regenerate the ACL, the ideal matrix should be biodegradable, porous, and exhibit sufficient mechanical strength to allow formation of neoligament tissue. Researchers have developed ACL scaffolds with collagen fibers, silk, biodegradable polymers, and composites with limited success. Our group has developed a biomimetic ligament replacement by using 3D braiding technology. In this preliminary in vivo rabbit model study for ACL reconstruction, the histological and mechanical evaluation demonstrated excellent healing and regeneration with our cell-seeded, tissue-engineered ligament replacement. PMID:17360607

Biomimetic interfaces based on S-layer proteins, lipid membranes and functional biomolecules

PubMed Central

Schuster, Bernhard; Sleytr, Uwe B.

2014-01-01

Designing and utilization of biomimetic membrane systems generated by bottom-up processes is a rapidly growing scientific and engineering field. Elucidation of the supramolecular construction principle of archaeal cell envelopes composed of S-layer stabilized lipid membranes led to new strategies for generating highly stable functional lipid membranes at meso- and macroscopic scale. In this review, we provide a state-of-the-art survey of how S-layer proteins, lipids and polymers may be used as basic building blocks for the assembly of S-layer-supported lipid membranes. These biomimetic membrane systems are distinguished by a nanopatterned fluidity, enhanced stability and longevity and, thus, provide a dedicated reconstitution matrix for membrane-active peptides and transmembrane proteins. Exciting areas in the (lab-on-a-) biochip technology are combining composite S-layer membrane systems involving specific membrane functions with the silicon world. Thus, it might become possible to create artificial noses or tongues, where many receptor proteins have to be exposed and read out simultaneously. Moreover, S-layer-coated liposomes and emulsomes copying virus envelopes constitute promising nanoformulations for the production of novel targeting, delivery, encapsulation and imaging systems. PMID:24812051

Chemically specific coarse-grained models to investigate the structure of biomimetic membranes

DOE PAGES

Kowalik, Ma?gorzata; Schantz, Allen B.; Naqi, Abdullah; ...

2017-11-29

Biomimetic polymer/protein membranes are promising materials for DNA sequencing, sensors, drug delivery and water purification. These self-assembled structures are made from low molecular weight amphiphilic block copolymers (N hydrophobic < 40 for a diblock copolymer), including poly(ethylene oxide)–1,2-polybutadiene (EO–1,2-BD) and poly(ethylene oxide)–poly(ethyl ethylene) (EO–EE). To examine these membranes' nanoscale structure, we developed a coarse-grained molecular dynamics (CG MD) model for EO–1,2-BD and assembled a CG MD model for EO–EE using parameters from two published force fields. We observe that the polymers' hydrophobic core blocks are slightly stretched compared to the random coil configuration seen at higher molecular weights. We alsomore » observe an increase in the interdigitation of the hydrophobic leaflets with increasing molecular weight (consistent with literature). The hydration level of the EO corona (which may influence protein incorporation) is higher for membranes with a larger area/chain, regardless of whether EE or 1,2-BD forms the hydrophobic block. Our results provide a molecular-scale view of membrane packing and hydrophobicity, two important properties for creating polymer–protein biomimetic membranes.« less

Chemically specific coarse-grained models to investigate the structure of biomimetic membranes

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

Kowalik, Ma?gorzata; Schantz, Allen B.; Naqi, Abdullah

Biomimetic polymer/protein membranes are promising materials for DNA sequencing, sensors, drug delivery and water purification. These self-assembled structures are made from low molecular weight amphiphilic block copolymers (N hydrophobic < 40 for a diblock copolymer), including poly(ethylene oxide)–1,2-polybutadiene (EO–1,2-BD) and poly(ethylene oxide)–poly(ethyl ethylene) (EO–EE). To examine these membranes' nanoscale structure, we developed a coarse-grained molecular dynamics (CG MD) model for EO–1,2-BD and assembled a CG MD model for EO–EE using parameters from two published force fields. We observe that the polymers' hydrophobic core blocks are slightly stretched compared to the random coil configuration seen at higher molecular weights. We alsomore » observe an increase in the interdigitation of the hydrophobic leaflets with increasing molecular weight (consistent with literature). The hydration level of the EO corona (which may influence protein incorporation) is higher for membranes with a larger area/chain, regardless of whether EE or 1,2-BD forms the hydrophobic block. Our results provide a molecular-scale view of membrane packing and hydrophobicity, two important properties for creating polymer–protein biomimetic membranes.« less

Small-Scale Fabrication of Biomimetic Structures for Periodontal Regeneration

PubMed Central

Green, David W.; Lee, Jung-Seok; Jung, Han-Sung

2016-01-01

The periodontium is the supporting tissues for the tooth organ and is vulnerable to destruction, arising from overpopulating pathogenic bacteria and spirochaetes. The presence of microbes together with host responses can destroy large parts of the periodontium sometimes leading tooth loss. Permanent tissue replacements are made possible with tissue engineering techniques. However, existing periodontal biomaterials cannot promote proper tissue architectures, necessary tissue volumes within the periodontal pocket and a “water-tight” barrier, to become clinically acceptable. New kinds of small-scale engineered biomaterials, with increasing biological complexity are needed to guide proper biomimetic regeneration of periodontal tissues. So the ability to make compound structures with small modules, filled with tissue components, is a promising design strategy for simulating the anatomical complexity of the periodotium attachment complexes along the tooth root and the abutment with the tooth collar. Anatomical structures such as, intima, adventitia, and special compartments such as the epithelial cell rests of Malassez or a stellate reticulum niche need to be engineered from the start of regeneration to produce proper periodontium replacement. It is our contention that the positioning of tissue components at the origin is also necessary to promote self-organizing cell–cell connections, cell–matrix connections. This leads to accelerated, synchronized and well-formed tissue architectures and anatomies. This strategy is a highly effective preparation for tackling periodontitis, periodontium tissue resorption, and to ultimately prevent tooth loss. Furthermore, such biomimetic tissue replacements will tackle problems associated with dental implant support and perimimplantitis. PMID:26903872

Accelerating the design of biomimetic materials by integrating RNA-seq with proteomics and materials science.

PubMed

Guerette, Paul A; Hoon, Shawn; Seow, Yiqi; Raida, Manfred; Masic, Admir; Wong, Fong T; Ho, Vincent H B; Kong, Kiat Whye; Demirel, Melik C; Pena-Francesch, Abdon; Amini, Shahrouz; Tay, Gavin Z; Ding, Dawei; Miserez, Ali

2013-10-01

Efforts to engineer new materials inspired by biological structures are hampered by the lack of genomic data from many model organisms studied in biomimetic research. Here we show that biomimetic engineering can be accelerated by integrating high-throughput RNA-seq with proteomics and advanced materials characterization. This approach can be applied to a broad range of systems, as we illustrate by investigating diverse high-performance biological materials involved in embryo protection, adhesion and predation. In one example, we rapidly engineer recombinant squid sucker ring teeth proteins into a range of structural and functional materials, including nanopatterned surfaces and photo-cross-linked films that exceed the mechanical properties of most natural and synthetic polymers. Integrating RNA-seq with proteomics and materials science facilitates the molecular characterization of natural materials and the effective translation of their molecular designs into a wide range of bio-inspired materials.

Biomimetic synthesis of noble metal nanocrystals

NASA Astrophysics Data System (ADS)

Chiu, Chin-Yi

At the nanometer scale, the physical and chemical properties of materials heavily depend on their sizes and shapes. This fact has triggered considerable efforts in developing controllable nanomaterial synthesis. The controlled growth of colloidal nanocrystal is a kinetic process, in which high-energy facets grow faster and then vanish, leading to a nanocrystal enclosed by low-energy facets. Identifying a surfactant that can selectively bind to a particular crystal facet and thus lower its surface energy, is critical and challenging in shape controlled synthesis of nanocrystals. Biomolecules exhibiting exquisite molecular recognition properties can be exploited to precisely engineer nanostructured materials. In the first part of my thesis, we employed the phage display technique to select a specific multifunctional peptide sequence which can bind on Pd surface and mediate Pd crystal nucleation and growth, achieving size controlled synthesis of Pd nanocrystals in aqueous solution. We further demonstrated a rational biomimetic approach to the predictable synthesis of nanocrystals enclosed by a particular facet in the case of Pt. Specifically, Pt {100} and Pt {111} facet-specific peptides were identified and used to synthesize Pt nanocubes and Pt nano-tetrahedrons, respectively. The mechanistic studies of Pt {111} facet-specific peptide had led us to study the facet-selective adsorption of aromatic molecules on noble metal surfaces. The discoveries had achieved the development of design strategies to select facet-selective molecules which can synthesize nanocrystals with expected shapes in both Pt and Pd system. At last, we exploited Pt facet-specific peptides and controlled the molecular interaction to produce one- and three- dimensional nanostructures composed of anisotropic nanoparticles in synthetic conditions without supramolecular pre-organization, demonstrating the full potential of biomolecules in mediating material formation process. My research on biomimetic

Integrating biologically inspired nanomaterials and table-top stereolithography for 3D printed biomimetic osteochondral scaffolds

NASA Astrophysics Data System (ADS)

Castro, Nathan J.; O'Brien, Joseph; Zhang, Lijie Grace

2015-08-01

The osteochondral interface of an arthritic joint is notoriously difficult to regenerate due to its extremely poor regenerative capacity and complex stratified architecture. Native osteochondral tissue extracellular matrix is composed of numerous nanoscale organic and inorganic constituents. Although various tissue engineering strategies exist in addressing osteochondral defects, limitations persist with regards to tissue scaffolding which exhibit biomimetic cues at the nano to micro scale. In an effort to address this, the current work focused on 3D printing biomimetic nanocomposite scaffolds for improved osteochondral tissue regeneration. For this purpose, two biologically-inspired nanomaterials have been synthesized consisting of (1) osteoconductive nanocrystalline hydroxyapatite (nHA) (primary inorganic component of bone) and (2) core-shell poly(lactic-co-glycolic) acid (PLGA) nanospheres encapsulated with chondrogenic transforming growth-factor β1 (TGF-β1) for sustained delivery. Then, a novel table-top stereolithography 3D printer and the nano-ink (i.e., nHA + nanosphere + hydrogel) were employed to fabricate a porous and highly interconnected osteochondral scaffold with hierarchical nano-to-micro structure and spatiotemporal bioactive factor gradients. Our results showed that human bone marrow-derived mesenchymal stem cell adhesion, proliferation, and osteochondral differentiation were greatly improved in the biomimetic graded 3D printed osteochondral construct in vitro. The current work served to illustrate the efficacy of the nano-ink and current 3D printing technology for efficient fabrication of a novel nanocomposite hydrogel scaffold. In addition, tissue-specific growth factors illustrated a synergistic effect leading to increased cell adhesion and directed stem cell differentiation.

Biomimetic 'Green' Synthesis of Nanomaterials Using Antioxidants-Vitamins, Glutathione and Polyphenols from Tea and Wine

EPA Science Inventory

The presentation summarizes our recent activity in chemical synthesis of nanomaterials via benign biomimetic ‘greener’ alternatives,1 such as the use antioxidants present in a variety of natural products, and ubiquitous glutathione in aqueous media.2 Vitamins B1, B2, C, and tea ...

In vivo comparison of biomimetic approaches for tissue regeneration of the scarred vocal fold.

PubMed

Thibeault, Susan L; Klemuk, Sarah A; Smith, Marshall E; Leugers, Cecilia; Prestwich, Glenn

2009-07-01

The objective of this study was to determine if three different biomimetic approaches could facilitate tissue regeneration and improve viscoelastic properties in the scarred vocal fold lamina propria extracellular matrix (ECM). Twenty rabbit vocal folds were biopsied bilaterally; 2 months postinjury rabbits were unilaterally treated with (i) autologous fibroblasts, (ii) a semisynthetic ECM (sECM), or (iii) autologous fibroblasts encapsulated in sECM. Saline was injected as a control into the contralateral fold. Animals were sacrificed 2 months after treatment. Outcomes measured were procollagen, collagen, and fibronectin levels in the lamina propria, and tissue viscosity and elasticity across three frequency decades. All treatment groups demonstrated accelerated proliferation of the ECM. Vocal fold lamina propria treated with autologous fibroblasts were found to have significantly improved viscosity (p = 0.0077) and elasticity (p = 0.0081) compared to saline. This treatment group had significantly elevated fibronectin levels. sECM and autologous fibroblasts/sECM groups had significantly elevated levels of procollagen, collagen, and fibronectin, indicating abundant matrix production as compared to saline with viscoelastic measures that did not differ statistically from controls. The use of autologous fibroblasts led to better restoration of the vocal fold lamina propria biomechanical properties. Optimization of cell-scaffold interactions and subsequent cell behavior is necessary for utilization of scaffold and scaffold-cell approaches.

(Cryptand-222)potassium(+) (hydrogensulfido)[5,10,15,20-tetra­kis(2-pival­amido­phen­yl)porphyrinato]ferrate(II)

PubMed Central

Dhifet, Mondher; Belkhiria, Mohamed Salah; Daran, Jean-Claude; Nasri, Habib

2009-01-01

As part of a systematic investigation for a number of FeII porphyrin complexes used as biomimetic models for cytochrome P450, crystals of the title compound, [K(C18H36N2O6)][FeII(C64H64N8O4)(HS)], were prepared. The compound exhibits a non-planar conformation with major ruffling and saddling distortions. The average equatorial iron–pyrrole N atom [Fe—Np = 2.102 (2) Å] bond length and the distance between the FeII atom and the 24-atom core of the porphyrin ring (Fe—PC= 0.558 Å) are typical for high-spin iron(II) penta­coordinate porphyrinates. One of the tert-butyl groups in the structure is disordered over two sets with occupancies of 0.84 and 0.16. PMID:21583412

Surface modification of cellulose fibers: towards wood composites by biomimetics.

PubMed

Gradwell, Sheila E; Renneckar, Scott; Esker, Alan R; Heinze, Thomas; Gatenholm, Paul; Vaca-Garcia, Carlos; Glasser, Wolfgang

2004-01-01

A biomimetic approach was taken for studying the adsorption of a model copolymer (pullulan abietate, DS 0.027), representing the lignin-carbohydrate complex, to a model surface for cellulose fibers (Langmuir-Blodgett thin films of regenerated cellulose). Adsorption results were assayed using surface plasmon resonance spectroscopy (SPR) and atomic force microscopy (AFM). Rapid, spontaneous, and desorption-resistant surface modification resulted. This effort is viewed as a critical first step towards the permanent surface modification of cellulose fibers with a layer of molecules amenable to either enzymatic crosslinking for improved wood composites or thermoplastic consolidation.

Long-term, high frequency in situ measurements of intertidal mussel bed temperatures using biomimetic sensors

PubMed Central

Helmuth, Brian; Choi, Francis; Matzelle, Allison; Torossian, Jessica L.; Morello, Scott L.; Mislan, K.A.S.; Yamane, Lauren; Strickland, Denise; Szathmary, P. Lauren; Gilman, Sarah E.; Tockstein, Alyson; Hilbish, Thomas J.; Burrows, Michael T.; Power, Anne Marie; Gosling, Elizabeth; Mieszkowska, Nova; Harley, Christopher D.G.; Nishizaki, Michael; Carrington, Emily; Menge, Bruce; Petes, Laura; Foley, Melissa M.; Johnson, Angela; Poole, Megan; Noble, Mae M.; Richmond, Erin L.; Robart, Matt; Robinson, Jonathan; Sapp, Jerod; Sones, Jackie; Broitman, Bernardo R.; Denny, Mark W.; Mach, Katharine J.; Miller, Luke P.; O’Donnell, Michael; Ross, Philip; Hofmann, Gretchen E.; Zippay, Mackenzie; Blanchette, Carol; Macfarlan, J.A.; Carpizo-Ituarte, Eugenio; Ruttenberg, Benjamin; Peña Mejía, Carlos E.; McQuaid, Christopher D.; Lathlean, Justin; Monaco, Cristián J.; Nicastro, Katy R.; Zardi, Gerardo

2016-01-01

At a proximal level, the physiological impacts of global climate change on ectothermic organisms are manifest as changes in body temperatures. Especially for plants and animals exposed to direct solar radiation, body temperatures can be substantially different from air temperatures. We deployed biomimetic sensors that approximate the thermal characteristics of intertidal mussels at 71 sites worldwide, from 1998-present. Loggers recorded temperatures at 10–30 min intervals nearly continuously at multiple intertidal elevations. Comparisons against direct measurements of mussel tissue temperature indicated errors of ~2.0–2.5 °C, during daily fluctuations that often exceeded 15°–20 °C. Geographic patterns in thermal stress based on biomimetic logger measurements were generally far more complex than anticipated based only on ‘habitat-level’ measurements of air or sea surface temperature. This unique data set provides an opportunity to link physiological measurements with spatially- and temporally-explicit field observations of body temperature. PMID:27727238

Long-term, high frequency in situ measurements of intertidal mussel bed temperatures using biomimetic sensors

NASA Astrophysics Data System (ADS)

Helmuth, Brian; Choi, Francis; Matzelle, Allison; Torossian, Jessica L.; Morello, Scott L.; Mislan, K. A. S.; Yamane, Lauren; Strickland, Denise; Szathmary, P. Lauren; Gilman, Sarah E.; Tockstein, Alyson; Hilbish, Thomas J.; Burrows, Michael T.; Power, Anne Marie; Gosling, Elizabeth; Mieszkowska, Nova; Harley, Christopher D. G.; Nishizaki, Michael; Carrington, Emily; Menge, Bruce; Petes, Laura; Foley, Melissa M.; Johnson, Angela; Poole, Megan; Noble, Mae M.; Richmond, Erin L.; Robart, Matt; Robinson, Jonathan; Sapp, Jerod; Sones, Jackie; Broitman, Bernardo R.; Denny, Mark W.; Mach, Katharine J.; Miller, Luke P.; O'Donnell, Michael; Ross, Philip; Hofmann, Gretchen E.; Zippay, Mackenzie; Blanchette, Carol; Macfarlan, J. A.; Carpizo-Ituarte, Eugenio; Ruttenberg, Benjamin; Peña Mejía, Carlos E.; McQuaid, Christopher D.; Lathlean, Justin; Monaco, Cristián J.; Nicastro, Katy R.; Zardi, Gerardo

2016-10-01

At a proximal level, the physiological impacts of global climate change on ectothermic organisms are manifest as changes in body temperatures. Especially for plants and animals exposed to direct solar radiation, body temperatures can be substantially different from air temperatures. We deployed biomimetic sensors that approximate the thermal characteristics of intertidal mussels at 71 sites worldwide, from 1998-present. Loggers recorded temperatures at 10-30 min intervals nearly continuously at multiple intertidal elevations. Comparisons against direct measurements of mussel tissue temperature indicated errors of ~2.0-2.5 °C, during daily fluctuations that often exceeded 15°-20 °C. Geographic patterns in thermal stress based on biomimetic logger measurements were generally far more complex than anticipated based only on ‘habitat-level’ measurements of air or sea surface temperature. This unique data set provides an opportunity to link physiological measurements with spatially- and temporally-explicit field observations of body temperature.

Biomimetics: From Bioinformatics to Rational Design of Dendrimers as Gene Carriers.

PubMed

Márquez-Miranda, Valeria; Camarada, María Belén; Araya-Durán, Ingrid; Varas-Concha, Ignacio; Almonacid, Daniel Eduardo; González-Nilo, Fernando Danilo

2015-01-01

Biomimetics, or the use of principles of Nature for developing new materials, is a paradigm that could help Nanomedicine tremendously. One of the current challenges in Nanomedicine is the rational design of new efficient and safer gene carriers. Poly(amidoamine) (PAMAM) dendrimers are a well-known class of nanoparticles, extensively used as non-viral nucleic acid carriers, due to their positively charged end-groups. Yet, there are still several aspects that can be improved for their successful application in in vitro and in vivo systems, including their affinity for nucleic acids as well as lowering their cytotoxicity. In the search of new functional groups that could be used as new dendrimer-reactive groups, we followed a biomimetic approach to determine the amino acids with highest prevalence in protein-DNA interactions. Then we introduced them individually as terminal groups of dendrimers, generating a new class of nanoparticles. Molecular dynamics studies of two systems: PAMAM-Arg and PAMAM-Lys were also performed in order to describe the formation of complexes with DNA. Results confirmed that the introduction of amino acids as terminal groups in a dendrimer increases their affinity for DNA and the interactions in the complexes were characterized at atomic level. We end up by briefly discussing additional modifications that can be made to PAMAM dendrimers to turned them into promising new gene carriers.

Biomimetics: From Bioinformatics to Rational Design of Dendrimers as Gene Carriers

PubMed Central

Araya-Durán, Ingrid; Varas-Concha, Ignacio; Almonacid, Daniel Eduardo; González-Nilo, Fernando Danilo

2015-01-01

Biomimetics, or the use of principles of Nature for developing new materials, is a paradigm that could help Nanomedicine tremendously. One of the current challenges in Nanomedicine is the rational design of new efficient and safer gene carriers. Poly(amidoamine) (PAMAM) dendrimers are a well-known class of nanoparticles, extensively used as non-viral nucleic acid carriers, due to their positively charged end-groups. Yet, there are still several aspects that can be improved for their successful application in in vitro and in vivo systems, including their affinity for nucleic acids as well as lowering their cytotoxicity. In the search of new functional groups that could be used as new dendrimer-reactive groups, we followed a biomimetic approach to determine the amino acids with highest prevalence in protein-DNA interactions. Then we introduced them individually as terminal groups of dendrimers, generating a new class of nanoparticles. Molecular dynamics studies of two systems: PAMAM-Arg and PAMAM-Lys were also performed in order to describe the formation of complexes with DNA. Results confirmed that the introduction of amino acids as terminal groups in a dendrimer increases their affinity for DNA and the interactions in the complexes were characterized at atomic level. We end up by briefly discussing additional modifications that can be made to PAMAM dendrimers to turned them into promising new gene carriers. PMID:26382062

Effect of titania content and biomimetic coating on the mechanical properties of the Y-TZP/TiO2 composite.

PubMed

Miranda, Ranulfo Benedito de Paula; Miranda, Walter Gomes; Lazar, Dolores Ribeiro Ricci; Ussui, Valter; Marchi, Juliana; Cesar, Paulo Francisco

2018-02-01

To investigate the effect of titania addition (0, 10 and 30mol%) on the microstructure, relative density, Young's modulus (E), Poisson's ratio (υ), mechanical properties (flexural strength, σ f , and Weibull modulus, m) of a Y-TZP/TiO 2 composite. The effect of the presence of a biomimetic coating on the microstructure and mechanical properties was also evaluated. Y-TZP (3mol% of yttria) and Y-TZP/TiO 2 composite (10 or 30mol% of titania) were synthesized by co-precipitation. The powders were pressed and sintered at 1400°C/2h. The surfaces, with and without biomimetic coating, were characterized by X-ray diffraction analysis and scanning electron microscopy. The relative density was measured by the Archimedes' principle. E and υ were measured by ultrasonic pulse-echo method. For the mechanical properties the specimens (n=30 for each group) were tested in a universal testing machine. Titania addition increased the grain size of the composite and caused a significant decrease in the flexural strength (in MPa, control 815.4 a ; T10 455.7 b and T30 336.0 c ), E (in GPa, control 213.4 a ; T10 155.8 b and T30 134.0 c ) and relative density (control 99.0% a ; T10 94.4% c and T30 96.3% b ) of the Y-TZP/TiO 2 composite. The presence of 30% titania caused substantial increase in m and υ. Biomimetic coating did not affect the mechanical properties of the composite. The Y-TZP/TiO 2 composite coated with a layer of CaP has great potential to be used as implant material. Although addition of titania affected the properties of the composite, the application of a biomimetic coating did not jeopardize its reliability. Copyright © 2017 The Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Adsorption of nucleotides on biomimetic apatite: The case of adenosine 5‧ monophosphate (AMP)

NASA Astrophysics Data System (ADS)

Hammami, K.; Feki, H. El; Marsan, O.; Drouet, C.

2015-10-01

This work investigates the interaction between the nucleotide adenosine 5‧ monophosphate molecule (AMP) and a biomimetic nanocrystalline carbonated apatite as a model for bone mineral. The analogy of the apatite phase used in this work with biological apatite was first pointed out by complementary techniques. AMP adsorption isotherms were then investigated. Obtained data were fitted to a Sips isotherm with an exponent greater than one suggesting positive cooperativity among adsorbed molecules. The data were compared to a previous study relative to the adsorption of another nucleotide, cytidine monophosphate (CMP) onto a similar substrate, evidencing some effect of the chemical nature of the nucleic base. An enhanced adsorption was observed under acidic (pH 6) conditions as opposed to pH 7.4, which parallels the case of DNA adsorption on biomimetic apatite. An estimated standard Gibbs free energy associated to the adsorption process (ΔG°ads ≅ -22 kJ/mol) intermediate between "physisorption" and "chemisorption" was found. The analysis of the solids after adsorption pointed to the preservation of the main characteristics of the apatite substrate but shifts or enhancements of Raman bands attributed to AMP showed the existence of chemical interactions involving both the phosphate and adenine parts of AMP. This contribution adds to the works conducted in view of better understanding the interaction of DNA/RNA and their constitutive nucleotides and the surface of biomimetic apatites. It could prove helpful in disciplines such as bone diagenesis (DNA/apatite interface in aged bones) or nanomedicine (setup of DNA- or RNA-loaded apatite systems). Also, the adsorption of nucleic acids on minerals like apatites could have played a role in the preservation of such biomolecules in the varying conditions known to exist at the origin of life on Earth, underlining the importance of dedicated adsorption studies.

Novel biomimetic composite material for potentiometric screening of acetylcholine, a neurotransmitter in Alzheimer's disease.

PubMed

Sacramento, Ana S; Moreira, Felismina T C; Guerreiro, Joana L; Tavares, Ana P; Sales, M Goreti F

2017-10-01

This work describes a novel approach to produce an antibody-like biomimetic material. It includes preparing composite imprinted material never presented before, with highly conductive support nanostructures and assembling a high conductivity polymeric layer at low temperature. Overall, such highly conductive material may enhance the final features of electrically-based devices. Acetylcholine (ACh) was selected as target analyte, a neurotransmitter of importance in Alzheimer's disease. Potentiometric transduction was preferred, allowing quick responses and future adaptation to point-of-care requirements. The biomimetic material was obtained by bulk polymerization, where ACh was placed in a composite matrix of multiwalled carbon nanotubes (MWCNTs) and aniline (ANI). Subsequent polymerization, initiated by radical species, yielded a polymeric structure of polyaniline (PANI) acting as physical support of the composite. A non-imprinted material (NIM) having only PANI/MWCNT (without ACh) has been prepared for comparison of the biomimetic-imprinted material (BIM). RAMAN and Fourier Transform Infrared spectroscopy (FTIR), Transmission Electron microscopy (TEM), and Scanning Electron microscope (SEM) analysis characterized the structures of the materials. The ability of this biomaterial to rebind ACh was confirmed by including it as electroactive compound in a PVC/plasticizer mixture. The membranes with imprinted material and anionic additive presented the best analytical characteristics, with a sensitivity of 83.86mV decade -1 and limit of detection (LOD) of 3.45×10 -5 mol/L in HEPES buffer pH4.0. Good selectivity was observed against creatinine, creatine, glucose, cysteine and urea. The electrodes were also applied on synthetic serum samples and seemed a reliable tool for screening ACh in synthetic serum samples. The overall performance showed fast response, reusability, simplicity and low price. Copyright © 2017 Elsevier B.V. All rights reserved.

Ion transport and selectivity in biomimetic nanopores with pH-tunable zwitterionic polyelectrolyte brushes.

PubMed

Zeng, Zhenping; Yeh, Li-Hsien; Zhang, Mingkan; Qian, Shizhi

2015-10-28

Inspired by nature, functionalized nanopores with biomimetic structures have attracted growing interests in using them as novel platforms for applications of regulating ion and nanoparticle transport. To improve these emerging applications, we study theoretically for the first time the ion transport and selectivity in short nanopores functionalized with pH tunable, zwitterionic polyelectrolyte (PE) brushes. In addition to background salt ions, the study takes into account the presence of H(+) and OH(-) ions along with the chemistry reactions between functional groups on PE chains and protons. Due to ion concentration polarization, the charge density of PE layers is not homogeneously distributed and depends significantly on the background salt concentration, pH, grafting density of PE chains, and applied voltage bias, thereby resulting in many interesting and unexpected ion transport phenomena in the nanopore. For example, the ion selectivity of the biomimetic nanopore can be regulated from anion-selective (cation-selective) to cation-selective (anion-selective) by diminishing (raising) the solution pH when a sufficiently small grafting density of PE chains, large voltage bias, and low background salt concentration are applied.

Multiscale design and synthesis of biomimetic gradient protein/biosilica composites for interfacial tissue engineering.

PubMed

Guo, Jin; Li, Chunmei; Ling, Shengjie; Huang, Wenwen; Chen, Ying; Kaplan, David L

2017-11-01

Continuous gradients present at tissue interfaces such as osteochondral systems, reflect complex tissue functions and involve changes in extracellular matrix compositions, cell types and mechanical properties. New and versatile biomaterial strategies are needed to create suitable biomimetic engineered grafts for interfacial tissue engineering. Silk protein-based composites, coupled with selective peptides with mineralization domains, were utilized to mimic the soft-to-hard transition in osteochondral interfaces. The gradient composites supported tunable mineralization and mechanical properties corresponding to the spatial concentration gradient of the mineralization domains (R5 peptide). The composite system exhibited continuous transitions in terms of composition, structure and mechanical properties, as well as cytocompatibility and biodegradability. The gradient silicified silk/R5 composites promoted and regulated osteogenic differentiation of human mesenchymal stem cells in an osteoinductive environment in vitro. The cells differentiated along the composites in a manner consistent with the R5-gradient profile. This novel biomimetic gradient biomaterial design offers a useful approach to meet a broad range of needs in regenerative medicine. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nano-biomimetic carriers are implicated in mechanistic evaluation of intracellular gene delivery

NASA Astrophysics Data System (ADS)

Alipour, Mohsen; Hosseinkhani, Saman; Sheikhnejad, Reza; Cheraghi, Roya

2017-01-01

Several tissue specific non-viral carriers have been developed for gene delivery purposes. However, the inability to escape endosomes, undermines the efficacy of these carriers. Researchers inspired by HIV and influenza virus, have randomly used Gp41 and H5WYG fusogenic peptides in several gene delivery systems without any rational preference. Here for the first time, we have genetically engineered two Nano-biomimetic carriers composed of either HWYG (HNH) or Gp41 (GNH) that precisely provide identical conditions for the study and evaluation of these fusogenic peptides. The luciferase assay demonstrated a two-fold higher transfection efficiency of HNH compared to GNH. These nanocarriers also displayed equivalent properties in terms of DNA binding ability and DNA protection against serum nucleases and formed similar nanoparticles in terms of surface charge and size. Interestingly, hemolysis and cellular analysis demonstrated both of nanoparticles internalized into cells in similar rate and escaped from endosome with different efficiency. Furthermore, the structural analysis revealed the mechanisms responsible for the superior endosomal escaping capability of H5WYG. In conclusion, this study describes the rationale for using H5WYG peptide to deliver nucleic acids and suggests that using nano-biomimetic carriers to screen different endosomal release peptides, improves gene delivery significantly.

Bone tissue reactions to biomimetic ion-substituted apatite surfaces on titanium implants.

PubMed

Ballo, Ahmed M; Xia, Wei; Palmquist, Anders; Lindahl, Carl; Emanuelsson, Lena; Lausmaa, Jukka; Engqvist, Håkan; Thomsen, Peter

2012-07-07

The aim of this study was to evaluate the bone tissue response to strontium- and silicon-substituted apatite (Sr-HA and Si-HA) modified titanium (Ti) implants. Sr-HA, Si-HA and HA were grown on thermally oxidized Ti implants by a biomimetic process. Oxidized implants were used as controls. Surface properties, i.e. chemical composition, surface thickness, morphology/pore characteristics, crystal structure and roughness, were characterized with various analytical techniques. The implants were inserted in rat tibiae and block biopsies were prepared for histology, histomorphometry and scanning electron microscopy analysis. Histologically, new bone formed on all implant surfaces. The bone was deposited directly onto the Sr-HA and Si-HA implants without any intervening soft tissue. The statistical analysis showed significant higher amount of bone-implant contact (BIC) for the Si-doped HA modification (P = 0.030), whereas significant higher bone area (BA) for the Sr-doped HA modification (P = 0.034), when compared with the non-doped HA modification. The differences were most pronounced at the early time point. The healing time had a significant impact for both BA and BIC (P < 0.001). The present results show that biomimetically prepared Si-HA and Sr-HA on Ti implants provided bioactivity and promoted early bone formation.

Biomimetics: lessons from nature--an overview.

PubMed

Bhushan, Bharat

2009-04-28

Nature has developed materials, objects and processes that function from the macroscale to the nanoscale. These have gone through evolution over 3.8 Gyr. The emerging field of biomimetics allows one to mimic biology or nature to develop nanomaterials, nanodevices and processes. Properties of biological materials and surfaces result from a complex interplay between surface morphology and physical and chemical properties. Hierarchical structures with dimensions of features ranging from the macroscale to the nanoscale are extremely common in nature to provide properties of interest. Molecular-scale devices, superhydrophobicity, self-cleaning, drag reduction in fluid flow, energy conversion and conservation, high adhesion, reversible adhesion, aerodynamic lift, materials and fibres with high mechanical strength, biological self-assembly, antireflection, structural coloration, thermal insulation, self-healing and sensory-aid mechanisms are some of the examples found in nature that are of commercial interest. This paper provides a broad overview of the various objects and processes of interest found in nature and applications under development or available in the marketplace.

Biomimetic Nanofibrillation in Two-Component Biopolymer Blends with Structural Analogs to Spider Silk

NASA Astrophysics Data System (ADS)

Xie, Lan; Xu, Huan; Li, Liang-Bin; Hsiao, Benjamin S.; Zhong, Gan-Ji; Li, Zhong-Ming

2016-10-01

Despite the enormous potential in bioinspired fabrication of high-strength structure by mimicking the spinning process of spider silk, currently accessible routes (e.g., microfluidic and electrospinning approaches) still have substantial function gaps in providing precision control over the nanofibrillar superstructure, crystalline morphology or molecular orientation. Here the concept of biomimetic nanofibrillation, by copying the spiders’ spinning principles, was conceived to build silk-mimicking hierarchies in two-phase biodegradable blends, strategically involving the stepwise integration of elongational shear and high-pressure shear. Phase separation confined on nanoscale, together with deformation of discrete phases and pre-alignment of polymer chains, was triggered in the elongational shear, conferring the readiness for direct nanofibrillation in the latter shearing stage. The orderly aligned nanofibrils, featuring an ultralow diameter of around 100 nm and the “rigid-soft” system crosslinked by nanocrystal domains like silk protein dopes, were secreted by fine nanochannels. The incorporation of multiscale silk-mimicking structures afforded exceptional combination of strength, ductility and toughness for the nanofibrillar polymer composites. The proposed spider spinning-mimicking strategy, offering the biomimetic function integration unattainable with current approaches, may prompt materials scientists to pursue biopolymer mimics of silk with high performance yet light weight.

Biomimetic Nanofibrillation in Two-Component Biopolymer Blends with Structural Analogs to Spider Silk.

PubMed

Xie, Lan; Xu, Huan; Li, Liang-Bin; Hsiao, Benjamin S; Zhong, Gan-Ji; Li, Zhong-Ming

2016-10-03

Despite the enormous potential in bioinspired fabrication of high-strength structure by mimicking the spinning process of spider silk, currently accessible routes (e.g., microfluidic and electrospinning approaches) still have substantial function gaps in providing precision control over the nanofibrillar superstructure, crystalline morphology or molecular orientation. Here the concept of biomimetic nanofibrillation, by copying the spiders' spinning principles, was conceived to build silk-mimicking hierarchies in two-phase biodegradable blends, strategically involving the stepwise integration of elongational shear and high-pressure shear. Phase separation confined on nanoscale, together with deformation of discrete phases and pre-alignment of polymer chains, was triggered in the elongational shear, conferring the readiness for direct nanofibrillation in the latter shearing stage. The orderly aligned nanofibrils, featuring an ultralow diameter of around 100 nm and the "rigid-soft" system crosslinked by nanocrystal domains like silk protein dopes, were secreted by fine nanochannels. The incorporation of multiscale silk-mimicking structures afforded exceptional combination of strength, ductility and toughness for the nanofibrillar polymer composites. The proposed spider spinning-mimicking strategy, offering the biomimetic function integration unattainable with current approaches, may prompt materials scientists to pursue biopolymer mimics of silk with high performance yet light weight.

Nucleation of biomimetic apatite in synthetic body fluids: dense and porous scaffold development.

PubMed

Landi, Elena; Tampieri, Anna; Celotti, Giancarlo; Langenati, Ratih; Sandri, Monica; Sprio, Simone

2005-06-01

The effectiveness of synthetic body fluids (SBF) as biomimetic sources to synthesize carbonated hydroxyapatite (CHA) powder similar to the biological inorganic phase, in terms of composition and microstructure, was investigated. CHA apatite powders were prepared following two widely experimented routes: (1) calcium nitrate tetrahydrate and diammonium hydrogen phosphate and (2) calcium hydroxide and ortophosphoric acid, but using SBF as synthesis medium instead of pure water. The characteristics of the as-prepared powders were compared, also with the features of apatite powders synthesized via pure water-based classical methods. The powder thermal resistance and behaviour during densification were studied together with the mechanical properties of the dense samples. The sponge impregnation process was used to prepare porous samples having morphological and mechanical characteristics suitable for bone substitution. Using this novel synthesis was it possible to prepare nanosized (approximately equal to 20 nm), pure, carbonate apatite powder containing Mg, Na, K ions, with morphological and compositional features mimicking natural apatite and with improved thermal properties. After sintering at 1250 degrees C the carbonate-free apatite porous samples showed a surprising, high compressive strength together with a biomimetic morphology.

Using a binaural biomimetic array to identify bottom objects ensonified by echolocating dolphins

USGS Publications Warehouse

Heiweg, D.A.; Moore, P.W.; Martin, S.W.; Dankiewicz, L.A.

2006-01-01

The development of a unique dolphin biomimetic sonar produced data that were used to study signal processing methods for object identification. Echoes from four metallic objects proud on the bottom, and a substrate-only condition, were generated by bottlenose dolphins trained to ensonify the targets in very shallow water. Using the two-element ('binaural') receive array, object echo spectra were collected and submitted for identification to four neural network architectures. Identification accuracy was evaluated over two receive array configurations, and five signal processing schemes. The four neural networks included backpropagation, learning vector quantization, genetic learning and probabilistic network architectures. The processing schemes included four methods that capitalized on the binaural data, plus a monaural benchmark process. All the schemes resulted in above-chance identification accuracy when applied to learning vector quantization and backpropagation. Beam-forming or concatenation of spectra from both receive elements outperformed the monaural benchmark, with higher sensitivity and lower bias. Ultimately, best object identification performance was achieved by the learning vector quantization network supplied with beam-formed data. The advantages of multi-element signal processing for object identification are clearly demonstrated in this development of a first-ever dolphin biomimetic sonar. ?? 2006 IOP Publishing Ltd.

Engineering biomimetic hair bundle sensors for underwater sensing applications

NASA Astrophysics Data System (ADS)

Kottapalli, Ajay Giri Prakash; Asadnia, Mohsen; Karavitaki, K. Domenica; Warkiani, Majid Ebrahimi; Miao, Jianmin; Corey, David P.; Triantafyllou, Michael

2018-05-01

We present the fabrication of an artificial MEMS hair bundle sensor designed to approximate the structural and functional principles of the flow-sensing bundles found in fish neuromast hair cells. The sensor consists of micro-pillars of graded height connected with piezoelectric nanofiber "tip-links" and encapsulated by a hydrogel cupula-like structure. Fluid drag force actuates the hydrogel cupula and deflects the micro-pillar bundle, stretching the nanofibers and generating electric charges. These biomimetic sensors achieve an ultrahigh sensitivity of 0.286 mV/(mm/s) and an extremely low threshold detection limit of 8.24 µm/s. A complete version of this paper has been published [1].

Acoustic beam control in biomimetic projector via velocity gradient

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

Gao, Xiaowei; Dong, Erqian; Song, Zhongchang

A biomimetic projector (BioP) based on computerized tomography of pygmy sperm whale's biosonar system has been designed using gradient-index (GRIN) material. The directivity of this BioP device was investigated as function of frequency and the velocity gradient of the GRIN material. A strong beam control over a broad bandwidth at the subwavelength scale has been achieved. Compared with a bare subwavelength source, the main lobe pressure of the BioP is about five times as high and the angular resolution is one order of magnitude better. Our results indicate that this BioP has excellent application potential in miniaturized underwater sonars.

Acoustic beam control in biomimetic projector via velocity gradient

NASA Astrophysics Data System (ADS)

Gao, Xiaowei; Zhang, Yu; Cao, Wenwu; Dong, Erqian; Song, Zhongchang; Li, Songhai; Tang, Liguo; Zhang, Sai

2016-07-01

A biomimetic projector (BioP) based on computerized tomography of pygmy sperm whale's biosonar system has been designed using gradient-index (GRIN) material. The directivity of this BioP device was investigated as function of frequency and the velocity gradient of the GRIN material. A strong beam control over a broad bandwidth at the subwavelength scale has been achieved. Compared with a bare subwavelength source, the main lobe pressure of the BioP is about five times as high and the angular resolution is one order of magnitude better. Our results indicate that this BioP has excellent application potential in miniaturized underwater sonars.

Synthesis and Ligand Non-Innocence of Thiolate-Ligated (N4S) Iron(II) and Nickel(II) Bis(imino)pyridine Complexes

PubMed Central

Widger, Leland R.; Jiang, Yunbo; Siegler, Maxime; Kumar, Devesh; Latifi, Reza; de Visser, Sam P.; Jameson, Guy N.L.; Goldberg, David P.

2013-01-01

The known iron(II) complex [FeII(LN3S)(OTf)] (1) was used as starting material to prepare the new biomimetic (N4S(thiolate)) iron(II) complexes [FeII(LN3S)(py)](OTf) (2) and [FeII(LN3S)(DMAP)](OTf) (3), where LN3S is a tetradentate bis(imino)pyridine (BIP) derivative with a covalently tethered phenylthiolate donor. These complexes were characterized by X-ray crystallography, UV-vis, 1H NMR, and Mössbauer spectroscopy, as well as electrochemistry. A nickel(II) analogue, [NiII(LN3S)](BF4) (5), was also synthesized and characterized by structural and spectroscopic methods. Cyclic voltammetric studies showed 1 – 3 and 5 undergo a single reduction process with E1/2 between −0.9 to −1.2 V versus Fc+/Fc. Treatment of 3 with 0.5% Na/Hg amalgam gave the mono-reduced complex [Fe(LN3S)(DMAP)]0 (4), which was characterized by X-ray crystallography, UV-vis, EPR (g = [2.155, 2.057, 2.038]) and Mössbauer (δ = 0.33 mm s−1; ΔEQ = 2.04 mm s−1) spectroscopies. Computational methods (DFT) were employed to model complexes 3 – 5. The combined experimental and computational studies show that 1 – 3 are 5-coordinate, high-spin (S = 2) FeII complexes, whereas 4 is best described as a 5-coordinate, intermediate-spin (S = 1) FeII complex antiferromagnetically coupled to a ligand radical. This unique electronic configuration leads to an overall doublet spin (Stotal = ½) ground state. Complexes 2 and 3 are shown to react with O2 to give S-oxygenated products, as previously reported for 1. In contrast, the mono-reduced 4 appears to react with O2 to give a mixture of S- and Fe-oxygenates. The nickel(II) complex 5 does not react with O2, and even when the mono-reduced nickel complex is produced, it appears to undergo only outer-sphere oxidation with O2. PMID:23992096

A Direct Electric Field-Aided Biomimetic Mineralization System for Inducing the Remineralization of Dentin Collagen Matrix

PubMed Central

Wu, Xiao-Ting; Mei, May Lei; Li, Quan-Li; Cao, Chris Ying; Chen, Jia-Long; Xia, Rong; Zhang, Zhi-Hong; Chu, Chun Hung

2015-01-01

This in vitro study aimed to accelerate the remineralization of a completely demineralized dentine collagen block in order to regenerate the dentinal microstructure of calcified collagen fibrils by a novel electric field-aided biomimetic mineralization system in the absence of non-collagenous proteins. Completely demineralized human dentine slices were prepared using ethylene diamine tetraacetic acid (EDTA) and treated with guanidine hydrochloride to extract the bound non-collagenous proteins. The completely demineralized dentine collagen blocks were then remineralized in a calcium chloride agarose hydrogel and a sodium hydrogen phosphate and fluoride agarose hydrogel. This process was accelerated by subjecting the hydrogels to electrophoresis at 20 mA for 4 and 12 h. X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and transmission electron microscopy (TEM) were used to evaluate the resultant calcification of the dentin collagen matrix. SEM indicated that mineral particles were precipitated on the intertubular dentin collagen matrix; these densely packed crystals mimicked the structure of the original mineralized dentin. However, the dentinal tubules were not occluded by the mineral crystals. XRD and EDX both confirmed that the deposited crystals were fluorinated hydroxyapatite. TEM revealed the existence of intrafibrillar and interfibrillar mineralization of the collagen fibrils. A novel electric field-aided biomimetic mineralization system was successfully developed to remineralize a completely demineralized dentine collagen matrix in the absence of non-collagenous proteins. This study developed an accelerated biomimetic mineralization system which can be a potential protocol for the biomineralization of dentinal defects. PMID:28793685

Biomimetic spiroid winglets for lift and drag control

NASA Astrophysics Data System (ADS)

Guerrero, Joel E.; Maestro, Dario; Bottaro, Alessandro

2012-01-01

In aeronautical engineering, drag reduction constitutes a challenge and there is room for improvement and innovative developments. The drag breakdown of a typical transport aircraft shows that the lift-induced drag can amount to as much as 40% of the total drag at cruise conditions and 80-90% of the total drag in take-off configuration. One way of reducing lift-induced drag is by using wingtip devices. By applying biomimetic abstraction of the principle behind a bird's wingtip feathers, we study spiroid wingtips, which look like an extended blended wingtip that bends upward by 360 degrees to form a large rigid ribbon. The numerical investigation of such a wingtip device is described and preliminary indications of its aerodynamic performance are provided.

Regenerated cellulose/wool blend enhanced biomimetic hydroxyapatite mineralization.

PubMed

Salama, Ahmed; El-Sakhawy, Mohamed

2016-11-01

The current article investigates the effect of bioactive cellulose/wool blend on calcium phosphate biomimetic mineralization. Regenerated cellulose/wool blend was prepared by dissolution-regeneration of neat cellulose and natural wool in 1-butyl-3-methyl imidazolium chloride [Bmim][Cl], as a solvent for the two polymers. Crystalline hydroxyapatite nanofibers with a uniform size, shape and dimension were formed after immersing the bioactive blend in simulated body fluid. The cytotoxicity of cellulose/wool/hydroxyapatite was studied using animal fibroblast baby hamster kidney cells (BHK-21) and the result displayed good cytocompatability. This research work presents a green processing method for the development of novel cellulose/wool/hydroxyapatite hybrid materials for tissue engineering applications. Copyright © 2016 Elsevier B.V. All rights reserved.

Biomimetic mineralization: long-term observations in patients with dentin sensitivity.

PubMed

Guentsch, Arndt; Seidler, Karin; Nietzsche, Sandor; Hefti, Arthur F; Preshaw, Philip M; Watts, David C; Jandt, Klaus D; Sigusch, Bernd W

2012-04-01

Cervical tooth erosion is increasingly observed among adults and frequently associated with dentin sensitivity (DS). This study evaluated the effectiveness on DS of a biomimetic mineralization system (BIMIN) in comparison to the current standard treatment (Gluma(®) Desensitizer, Gluma). In this single-blind, 2-arm study, 40 patients with confirmed cervical DS were randomized to either the test group or the positive control group. A Visual-Analog-Scale (VAS) was used to assess DS following stimulation of the exposed dentin with a 2-s air blast. Assessments were made at baseline (pre-treatment), 2 days, 4, 8 and 12 weeks, and 12 months after treatment. Two-stage replicas were obtained from the treated teeth and gold sputtered at baseline, and 2 days, 3 and 12 months after treatment. Surface topography of the treated cervical lesions and occlusion of dentinal tubules were investigated using scanning electron microscopy (SEM). Both treatments led to a statistically significant reduction (P<0.0001) in DS that persisted over the entire 12-month observation period. Differences in DS between the treatments were not statistically significant. SEM photomicrographs demonstrated that a mineral layer concealed the dentinal tubules in the test group. In contrast, numerous dentinal tubules remained visible in cervical defects that were treated with Gluma. A biomimetic mineralization kit was successfully used to treat patients exhibiting DS. The effect was similar to using Gluma, and was likely the result of the deposition of an enamel-like layer on the exposed cervical dentin. Copyright © 2012 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved.

Biomimetic mineralized hierarchical hybrid scaffolds based on in situ synthesis of nano-hydroxyapatite/chitosan/chondroitin sulfate/hyaluronic acid for bone tissue engineering.

PubMed

Hu, Yimin; Chen, Jingdi; Fan, Tiantang; Zhang, Yujue; Zhao, Yao; Shi, Xuetao; Zhang, Qiqing

2017-09-01

Biomimetic mineralized hybrid scaffolds are widely used as natural bone substitute materials in tissue engineering by mimicking vital characters of extracellular matrix (ECM). However, the fabrication of hybrid scaffolds with suitable mechanical properties and good biocompatibility remains a challenge. To solve the problems mentioned above, biomimetic calcium phosphate mineralized organic-inorganic hybrid scaffold composed of nano hydroxyapatite (nHAP), Chitosan (CS), Chondroitin sulfate (CSA) and hyaluronic acid (HA) with hierarchical micro/nano structures was successfully developed. In this process, an efficient and easy-to-accomplish method combining in situ biomimetic synthesis with freeze-drying technology was applied. The chemical structure of the scaffolds was confirmed by Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Surface morphology of scaffolds was characterized by Scanning electron microscopy (SEM). The nHAP/CS/CSA/HA hybrid scaffolds with a well-distributed pore size showed suitable mechanical strength which is not only due to the addition of the nHAP but also the interaction between the positively charged CS and the negatively charged CSA and HA. Simultaneously, the biocompatibility was evaluated by the MTT cytotoxicity assay, alkaline phosphatase (ALP) activity, Hoechst 33258 fluorescence staining. All those results proved that the scaffolds possess good biocompatibility and the components added have enhanced the proliferation and differentiation of osteoblast. Thus, it can be anticipated that the in situ biomimetic mineralized nHAP/CS/CAS/HA hybrid scaffolds will be promising candidates for bone tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

Advances in modelling of biomimetic fluid flow at different scales

PubMed Central

2011-01-01

The biomimetic flow at different scales has been discussed at length. The need of looking into the biological surfaces and morphologies and both geometrical and physical similarities to imitate the technological products and processes has been emphasized. The complex fluid flow and heat transfer problems, the fluid-interface and the physics involved at multiscale and macro-, meso-, micro- and nano-scales have been discussed. The flow and heat transfer simulation is done by various CFD solvers including Navier-Stokes and energy equations, lattice Boltzmann method and molecular dynamics method. Combined continuum-molecular dynamics method is also reviewed. PMID:21711847

Evaluation of a biomimetic 3D substrate based on the Human Elastin-like Polypeptides (HELPs) model system for elastolytic activity detection.

PubMed

Corich, Lucia; Busetti, Marina; Petix, Vincenzo; Passamonti, Sabina; Bandiera, Antonella

2017-08-10

Elastin is a fibrous protein that confers elasticity to tissues such as skin, arteries and lung. It is extensively cross-linked, highly hydrophobic and insoluble. Nevertheless, elastin can be hydrolysed by bacterial proteases in infectious diseases, resulting in more or less severe tissue damage. Thus, development of substrates able to reliably and specifically detect pathogen-secreted elastolytic activity is needed to improve the in vitro evaluation of the injury that bacterial proteases may provoke. In this work, two human biomimetic elastin polypeptides, HELP and HELP1, as well as the matrices derived from HELP, have been probed as substrates for elastolytic activity detection. Thirty strains of Pseudomonas aeruginosa isolated from cystic fibrosis patients were analyzed in parallel with standard substrates, to detect proteolytic and elastolytic activity. Results point to the HELP-based 3D matrix as an interesting biomimetic model of elastin to assess bacterial elastolytic activity in vitro. Moreover, this model substrate enables to further elucidate the mechanism underlying elastin degradation at molecular level, as well as to develop biomimetic material-based devices responsive to external stimuli. Copyright © 2017 Elsevier B.V. All rights reserved.

Mechanistic study of the biomimetic synthesis of flavonolignan diastereoisomers in milk thistle.

PubMed

Althagafy, Hanan S; Meza-Aviña, Maria Elena; Oberlies, Nicholas H; Croatt, Mitchell P

2013-08-02

The mechanism for the biomimetic synthesis of flavonolignan diastereoisomers in milk thistle is proposed to proceed by single-electron oxidation of coniferyl alcohol, subsequent reaction with one of the oxygen atoms of taxifolin's catechol moiety, and finally, further oxidation to form four of the major components of silymarin: silybin A, silybin B, isosilybin A, and isosilybin B. This mechanism is significantly different from a previously proposed process that involves the coupling of two independently formed radicals.

Universal poroelastic mechanism for hydraulic signals in biomimetic and natural branches

PubMed Central

Louf, J.-F.; Guéna, G.; Badel, E.; Forterre, Y.

2017-01-01

Plants constantly undergo external mechanical loads such as wind or touch and respond to these stimuli by acclimating their growth processes. A fascinating feature of this mechanical-induced growth response is that it can occur rapidly and at long distance from the initial site of stimulation, suggesting the existence of a fast signal that propagates across the whole plant. The nature and origin of the signal is still not understood, but it has been recently suggested that it could be purely mechanical and originate from the coupling between the local deformation of the tissues (bending) and the water pressure in the plant vascular system. Here, we address the physical origin of this hydromechanical coupling using a biomimetic strategy. We designed soft artificial branches perforated with longitudinal liquid-filled channels that mimic the basic features of natural stems and branches. In response to bending, a strong overpressure is generated in the channels that varies quadratically with the bending curvature. A model based on a mechanism analogous to the ovalization of hollow tubes enables us to predict quantitatively this nonlinear poroelastic response and identify the key physical parameters that control the generation of the pressure pulse. Further experiments conducted on natural tree branches reveal the same phenomenology. Once rescaled by the model prediction, both the biomimetic and natural branches fall on the same master curve, enlightening the universality of our poroelastic mechanism for the generation of hydraulic signals in plants. PMID:28973910

Biomechanical evaluation of a biomimetic spinal construct.

PubMed

Wang, Tian; Ball, Jonathon R; Pelletier, Mattew H; Walsh, William R

2014-12-01

Laboratory spinal biomechanical tests using human cadaveric or animal spines have limitations in terms of disease transmission, high sample variability, decay and fatigue during extended testing protocols. Therefore, a synthetic biomimetic spine model may be an acceptable substitute. The goal of current study is to evaluate the properties of a synthetic biomimetic spine model; also to assess the mechanical performance of lateral plating following lateral interbody fusion. Three L3/4 synthetic spinal motion segments were examined using a validated pure moment testing system. Moments (±7.5 Nm) were applied in flexion-extension (FE), lateral bending (LB) and axial rotation (AR) at 1Hz for total 10000 cycles in MTS Bionix. An additional test was performed 12 hours after 10000 cycles. A ±10 Nm cycle was also performed to allow provide comparison to the literature. For implantation evaluation, each model was tested in the 4 following conditions: 1) intact, 2) lateral cage alone, 3) lateral cage and plate 4) anterior cage and plate. Results were analysed using ANOVA with post-hoc Tukey's HSD test. Range of motion (ROM) exhibited logarithmic growth with cycle number (increases of 16%, 37.5% and 24.3% in AR, FE and LB respectively). No signification difference (p > 0.1) was detected between 4 cycles, 10000 cycles and 12 hour rest stages. All measured parameters were comparable to that of reported cadaveric values. The ROM for a lateral cage and plate construct was not significantly different to the anterior lumbar interbody construct for FE (p = 1.00), LB (p = 0.995) and AR (p = 0.837). Based on anatomical and biomechanical similarities, the synthetic spine tested here provides a reasonable model to represent the human lumbar spine. Repeated testing did not dramatically alter biomechanics which may allow non-destructive testing between many different procedures and devices without the worry of carry over effects. Small intra-specimen variability

Tubular inverse opal scaffolds for biomimetic vessels

NASA Astrophysics Data System (ADS)

Zhao, Ze; Wang, Jie; Lu, Jie; Yu, Yunru; Fu, Fanfan; Wang, Huan; Liu, Yuxiao; Zhao, Yuanjin; Gu, Zhongze

2016-07-01

There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially oriented elliptical pattern microstructures on their surfaces. It is demonstrated that these tailored tubular scaffolds can effectively make endothelial cells to form an integrated hollow tubular structure on their inner surface and induce smooth muscle cells to form a circumferential orientation on their outer surface. These features of our tubular scaffolds make them highly promising for the construction of biomimetic blood vessels.There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially

Superhydrophobic, Biomimetic Surfaces with High and Low Adhesion, Optical Transmittance, and Nanoscale Mechanical Wear Resistance

NASA Astrophysics Data System (ADS)

Ebert, Daniel R.

Superhydrophobic surfaces (defined as surfaces having water contact angle greater than 150°) show great promise for use in a rapidly growing number of engineering applications, ranging from biomedical devices to fluid drag reduction in pipelines. In nature, the surfaces of many organisms, such as certain plant leaves, are known to exhibit superhydrophobicity. In some cases, droplet adhesion is very low (droplet rolls away easily), while in other cases adhesion is high (droplet remains adhered when surface is inverted). The recent advent and development of microscopes with resolution down to a few nanometers (such as atomic force microscopes and scanning electron microscopes) has allowed for in-depth understanding of the micro- and nanoscale mechanisms employed by these plant leaves and other natural surfaces to achieve their particular wetting properties. Biomimetics (or "mimicking nature") is therefore a very promising approach for the development of engineering surfaces with desired wetting characteristics. However, research in creating biomimetic surfaces is still in its early stages, and many of the surfaces created thus far are not mechanically robust, which is required for many potential real-world applications. In addition, for applications such as self-cleaning windows and solar panels, optical transparency is required. In this thesis, a set of original studies are presented in which superhydrophobic surfaces were designed based on biomimetics and fabricated using a wide of variety of techniques. The surfaces were characterized with regard to wetting characteristics such as water contact angle and contact angle hysteresis, micro- and nanoscale mechanical durability, and in some cases optical transmittance. Theoretical wetting models served as guides both in the design and in the understanding of experimental results, especially in regard to different wetting regime and regime transition. This work provides important conclusions and valuable insight for

Molecular biomimetics: GEPI-based biological routes to technology.

PubMed

Tamerler, Candan; Khatayevich, Dmitriy; Gungormus, Mustafa; Kacar, Turgay; Oren, E Emre; Hnilova, Marketa; Sarikaya, Mehmet

2010-01-01

In nature, the viability of biological systems is sustained via specific interactions among the tens of thousands of proteins, the major building blocks of organisms from the simplest single-celled to the most complex multicellular species. Biomolecule-material interaction is accomplished with molecular specificity and efficiency leading to the formation of controlled structures and functions at all scales of dimensional hierarchy. Through evolution, Mother Nature developed molecular recognition by successive cycles of mutation and selection. Molecular specificity of probe-target interactions, e.g., ligand-receptor, antigen-antibody, is always based on specific peptide molecular recognition. Using biology as a guide, we can now understand, engineer, and control peptide-material interactions and exploit them as a new design tool for novel materials and systems. We adapted the protocols of combinatorially designed peptide libraries, via both cell surface or phage display methods; using these we select short peptides with specificity to a variety of practical materials. These genetically engineered peptides for inorganics (GEPI) are then studied experimentally to establish their binding kinetics and surface stability. The bound peptide structure and conformations are interrogated both experimentally and via modeling, and self-assembly characteristics are tested via atomic force microscopy. We further engineer the peptide binding and assembly characteristics using a computational biomimetics approach where bioinformatics based peptide-sequence similarity analysis is developed to design higher generation function-specific peptides. The molecular biomimetic approach opens up new avenues for the design and utilization of multifunctional molecular systems in a wide-range of applications from tissue engineering, disease diagnostics, and therapeutics to various areas of nanotechnology where integration is required among inorganic, organic and biological materials. Here, we

Hierarchically organized architecture of potassium hydrogen phthalate and poly(acrylic acid): toward a general strategy for biomimetic crystal design.

PubMed

Oaki, Yuya; Imai, Hiroaki

2005-12-28

A hierarchically organized architecture in multiple scales was generated from potassium hydrogen phthalate crystals and poly(acrylic acid) based on our novel biomimetic approach with an exquisite association of polymers on crystallization.

Biomimetic approaches to control soluble concentration gradients in biomaterials.

PubMed

Nguyen, Eric H; Schwartz, Michael P; Murphy, William L

2011-04-08

Soluble concentration gradients play a critical role in controlling tissue formation during embryonic development. The importance of soluble signaling in biology has motivated engineers to design systems that allow precise and quantitative manipulation of gradient formation in vitro. Engineering techniques have increasingly moved to the third dimension in order to provide more physiologically relevant models to study the biological role of gradient formation and to guide strategies for controlling new tissue formation for therapeutic applications. This review provides an overview of efforts to design biomimetic strategies for soluble gradient formation, with a focus on microfluidic techniques and biomaterials approaches for moving gradient generation to the third dimension. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Crustacean-derived biomimetic components and nanostructured composites.

PubMed

Grunenfelder, Lessa Kay; Herrera, Steven; Kisailus, David

2014-08-27

Over millions of years, the crustacean exoskeleton has evolved into a rigid, tough, and complex cuticle that is used for structural support, mobility, protection of vital organs, and defense against predation. The crustacean cuticle is characterized by a hierarchically arranged chitin fiber scaffold, mineralized predominately by calcium carbonate and/or calcium phosphate. The structural organization of the mineral and organic within the cuticle occurs over multiple length scales, resulting in a strong and tough biological composite. Here, the ultrastructural details observed in three species of crustacean are reviewed: the American lobster (Homarus americanus), the edible crab (Cancer pagurus), and the peacock mantis shrimp (Odontodactylus scyllarus). The Review concludes with a discussion of recent advances in the development of biomimetics with controlled organic scaffolding, mineralization, and the construction of nanoscale composites, inspired by the organization and formation of the crustacean cuticle. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Physiology, biomechanics, and biomimetics of hagfish slime.

PubMed

Fudge, Douglas S; Schorno, Sarah; Ferraro, Shannon

2015-01-01

Hagfishes thwart attacks by fish predators by producing liters of defensive slime. The slime is produced when slime gland exudate is released into the predator's mouth, where it deploys in a fraction of a second and clogs the gills. Slime exudate is composed mainly of secretory products from two cell types, gland mucous cells and gland thread cells, which produce the mucous and fibrous components of the slime, respectively. Here, we review what is known about the composition of the slime, morphology of the slime gland, and physiology of the cells that produce the slime. We also discuss several of the mechanisms involved in the deployment of both mucous and thread cells during the transition from thick glandular exudate to ultradilute material. We review biomechanical aspects of the slime, along with recent efforts to produce biomimetic slime thread analogs, and end with a discussion of how hagfish slime may have evolved.

Clues for biomimetics from natural composite materials

PubMed Central

Lapidot, Shaul; Meirovitch, Sigal; Sharon, Sigal; Heyman, Arnon; Kaplan, David L; Shoseyov, Oded

2013-01-01

Bio-inspired material systems are derived from different living organisms such as plants, arthropods, mammals and marine organisms. These biomaterial systems from nature are always present in the form of composites, with molecular-scale interactions optimized to direct functional features. With interest in replacing synthetic materials with natural materials due to biocompatibility, sustainability and green chemistry issues, it is important to understand the molecular structure and chemistry of the raw component materials to also learn from their natural engineering, interfaces and interactions leading to durable and highly functional material architectures. This review will focus on applications of biomaterials in single material forms, as well as biomimetic composites inspired by natural organizational features. Examples of different natural composite systems will be described, followed by implementation of the principles underlying their composite organization into artificial bio-inspired systems for materials with new functional features for future medicine. PMID:22994958

Clues for biomimetics from natural composite materials.

PubMed

Lapidot, Shaul; Meirovitch, Sigal; Sharon, Sigal; Heyman, Arnon; Kaplan, David L; Shoseyov, Oded

2012-09-01

Bio-inspired material systems are derived from different living organisms such as plants, arthropods, mammals and marine organisms. These biomaterial systems from nature are always present in the form of composites, with molecular-scale interactions optimized to direct functional features. With interest in replacing synthetic materials with natural materials due to biocompatibility, sustainability and green chemistry issues, it is important to understand the molecular structure and chemistry of the raw component materials to also learn from their natural engineering, interfaces and interactions leading to durable and highly functional material architectures. This review will focus on applications of biomaterials in single material forms, as well as biomimetic composites inspired by natural organizational features. Examples of different natural composite systems will be described, followed by implementation of the principles underlying their composite organization into artificial bio-inspired systems for materials with new functional features for future medicine.

Surface Topography and Mechanical Strain Promote Keratocyte Phenotype and Extracellular Matrix Formation in a Biomimetic 3D Corneal Model.

PubMed

Zhang, Wei; Chen, Jialin; Backman, Ludvig J; Malm, Adam D; Danielson, Patrik

2017-03-01

The optimal functionality of the native corneal stroma is mainly dependent on the well-ordered arrangement of extracellular matrix (ECM) and the pressurized structure. In order to develop an in vitro corneal model, it is crucial to mimic the in vivo microenvironment of the cornea. In this study, the influence of surface topography and mechanical strain on keratocyte phenotype and ECM formation within a biomimetic 3D corneal model is studied. By modifying the surface topography of materials, it is found that patterned silk fibroin film with 600 grooves mm -1 optimally supports cell alignment and ECM arrangement. Furthermore, treatment with 3% dome-shaped mechanical strain, which resembles the shape and mechanics of native cornea, significantly enhances the expression of keratocyte markers as compared to flat-shaped strain. Accordingly, a biomimetic 3D corneal model, in the form of a collagen-modified, silk fibroin-patterned construct subjected to 3% dome-shaped strain, is created. Compared to traditional 2D cultures, it supports a significantly higher expression of keratocyte and ECM markers, and in conclusion better maintains keratocyte phenotype, alignment, and fusiform cell shape. Therefore, the novel biomimetic 3D corneal model developed in this study serves as a useful in vitro 3D culture model to improve current 2D cultures for corneal studies. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The optimal SAM surface functional group for producing a biomimetic HA coating on Ti.

PubMed

Liu, D P; Majewski, P; O'Neill, B K; Ngothai, Y; Colby, C B

2006-06-15

Commercial interest is growing in biomimetic methods that employ self assembled mono-layers (SAMs) to produce biocompatible HA coatings on Ti-based orthopedic implants. Recently, separate studies have considered HA formation for various SAM surface functional groups. However, these have often neglected to verify crystallinity of the HA coating, which is essential for optimal bioactivity. Furthermore, differing experimental and analytical methods make performance comparisons difficult. This article investigates and evaluates HA formation for four of the most promising surface functional groups: --OH, --SO(3)H, --PO(4)H(2) and --COOH. All of them successfully formed a HA coating at Ca/P ratios between 1.49 and 1.62. However, only the --SO(3)H and --COOH end groups produced a predominantly crystalline HA. Furthermore, the --COOH end group yielded the thickest layer and possessed crystalline characteristics very similar to that of the human bone. The --COOH end group appears to provide the optimal SAM surface interface for nucleation and growth of biomimetic crystalline HA. Intriguingly, this finding may lend support to explanations elsewhere of why human bone sialoprotein is such a potent nucleator of HA and is attributed to the protein's glutamic acid-rich sequences.

Influence of the modulated two-step synthesis of biogenic hydroxyapatite on biomimetic products' surface

NASA Astrophysics Data System (ADS)

Miculescu, Florin; Mocanu, Aura Cătălina; Stan, George E.; Miculescu, Marian; Maidaniuc, Andreea; Cîmpean, Anisoara; Mitran, Valentina; Voicu, Stefan Ioan; Machedon-Pisu, Teodor; Ciocan, Lucian Toma

2018-04-01

Processing calcium-rich natural resources, such as marble and mussel seashells, into biomimetic products could constitute an environmentally-friendly and economically sustainable alternative given their geographical widespread. Hitherto, their value for biomedicine was demonstrated only for seashells, with the technological exploitation approaches still facing challenges with respect to the identification of generic synthesis parameters capable to allow the reproducible and designed synthesis of calcium phosphate at an industrial-ready level. In this study was targeted the optimization of Rathje synthesis method for the fabrication of biogenic calcium phosphates, by conveniently adjusting the chemical composition of employed reagents. It was shown that post-synthesis heat-treatment of compacted powders is the key step for inducing structural transformations suitable to attain biomimetic products for reconstructive orthopedic applications. The sintered materials have been multi-parametricallyevaluated from morpho-compositional, structural, wettability, mechanical and cytocompatibility points of view and the results have been cross-examined and discussed. Convenient and efficient preparation routes to produce biogenic hydroxyapatite have been identified. The functional performances of the as-prepared biogenic ceramics endorse their use as a solid and inexpensive alternative source material for the fabrication of various bone regenerative products and implant coatings.

Fabrication of biomimetic resorption lacunae-like structure on titanium surface and its osteoblast responses

NASA Astrophysics Data System (ADS)

Huo, Fangjun; Guo, Weihua; Wu, Hao; Wang, Yueting; He, Gang; Xie, Li; Tian, Weidong

2018-04-01

Biomimetic specific surface structure could improve biological behaviors of specific cells and eventual tissue integration. Featuring titanium surface with structures resembling bone resorption lacunae (RL) can be a promising approach to improve the osteoblast responses and osseointegration of implants. As a most common used dental implant surface, sandblasting and acid etching (SLA) surface has micro-sized structures with dimensions similar to RL, but great differences exist when it comes to shape and contour. In this work, by anodizing titanium substrate in a novel HCOONa/CH3COONa electrolyte, RL-like crater structures were fabricated with highly similar size, shape and contour. Compared with SLA, it was much more similar to RL structure in shape and contour. Furthermore, through subsequent alkali-heat treatment, nano-sized structures that overlaid the whole surface were obtained, which further mimic undercuts features inside the RL. The as-prepared surface was consisted of crystalline titania and exhibited super-hydrophilicity with good stability. In vitro evaluation results showed that the surface could significantly improve adhesion, proliferation and differentiation of MG63 cells in comparison with SLA. This new method may be a promising candidate for biomimetic modification of titanium implant to promote osseointegration.

Biomimetic superhydrophobic surface of high adhesion fabricated with micronano binary structure on aluminum alloy.

PubMed

Liu, Yan; Liu, Jindan; Li, Shuyi; Liu, Jiaan; Han, Zhiwu; Ren, Luquan

2013-09-25

Triggered by the microstructure characteristics of the surfaces of typical plant leaves such as the petals of red roses, a biomimetic superhydrophobic surface with high adhesion is successfully fabricated on aluminum alloy. The essential procedure is that samples were processed by a laser, then immersed and etched in nitric acid and copper nitrate, and finally modified by DTS (CH3(CH2)11Si(OCH3)3). The obtained surfaces exhibit a binary structure consisting of microscale crater-like pits and nanoscale reticula. The superhydrophobicity can be simultaneously affected by the micronano binary structure and chemical composition of the surface. The contact angle of the superhydrophobic surface reaches up to 158.8 ± 2°. Especially, the surface with micronano binary structure is revealed to be an excellent adhesive property with petal-effect. Moreover, the superhydrophobic surfaces show excellent stability in aqueous solution with a large pH range and after being exposed long-term in air. In this way, the multifunctional biomimetic structural surface of the aluminum alloy is fabricated. Furthermore, the preparation technology in this article provides a new route for other metal materials.

A low-cost, high-yield fabrication method for producing optimized biomimetic dry adhesives

NASA Astrophysics Data System (ADS)

Sameoto, D.; Menon, C.

2009-11-01

We present a low-cost, large-scale method of fabricating biomimetic dry adhesives. This process is useful because it uses all photosensitive polymers with minimum fabrication costs or complexity to produce molds for silicone-based dry adhesives. A thick-film lift-off process is used to define molds using AZ 9260 photoresist, with a slow acting, deep UV sensitive material, PMGI, used as both an adhesion promoter for the AZ 9260 photoresist and as an undercutting material to produce mushroom-shaped fibers. The benefits to this process are ease of fabrication, wide range of potential layer thicknesses, no special surface treatment requirements to demold silicone adhesives and easy stripping of the full mold if process failure does occur. Sylgard® 184 silicone is used to cast full sheets of biomimetic dry adhesives off 4" diameter wafers, and different fiber geometries are tested for normal adhesion properties. Additionally, failure modes of the adhesive during fabrication are noted and strategies for avoiding these failures are discussed. We use this fabrication method to produce different fiber geometries with varying cap diameters and test them for normal adhesion strengths. The results indicate that the cap diameters relative to post diameters for mushroom-shaped fibers dominate the adhesion properties.

Characterization of a Biomimetic Mesophase Composed of Nonionic Surfactants and an Aqueous Solvent.

PubMed

Adrien, V; Rayan, G; Reffay, M; Porcar, L; Maldonado, A; Ducruix, A; Urbach, W; Taulier, N

2016-10-11

We have investigated the physical and biomimetic properties of a sponge (L 3 ) phase composed of pentaethylene glycol monododecyl ether (C 12 E 5 ), a nonionic surfactant, an aqueous solvent, and a cosurfactant. The following cosurfactants, commonly used for solubilizing membrane proteins, were incorporated: n-octyl-β-d-glucopyranoside (β-OG), n-dodecyl-β-d-maltopyranoside (DDM), 4-cyclohexyl-1-butyl-β-d-maltoside (CYMAL-4), and 5-cyclohexyl-1-pentyl-β-d-maltoside (CYMAL-5). Partial phase diagrams of these systems were created. The L 3 phase was characterized using crossed polarizers, diffusion of a fluorescent probe by fluorescence recovery after pattern photobleaching (FRAPP), and freeze fracture electron microscopy (FFEM). By varying the hydration of the phase, we were able to tune the distance between adjacent bilayers. The characteristic distance (d b ) of the phase was obtained from small angle scattering (SAXS/SANS) as well as from FFEM, which yielded complementary d b values. These d b values were neither affected by the nature of the cosurfactant nor by the addition of membrane proteins. These findings illustrate that a biomimetic surfactant sponge phase can be created in the presence of several common membrane protein-solubilizing detergents, thus making it a versatile medium for membrane protein studies.

Biomimetic Nanofibrillation in Two-Component Biopolymer Blends with Structural Analogs to Spider Silk

PubMed Central

Xie, Lan; Xu, Huan; Li, Liang-Bin; Hsiao, Benjamin S.; Zhong, Gan-Ji; Li, Zhong-Ming

2016-01-01

Despite the enormous potential in bioinspired fabrication of high-strength structure by mimicking the spinning process of spider silk, currently accessible routes (e.g., microfluidic and electrospinning approaches) still have substantial function gaps in providing precision control over the nanofibrillar superstructure, crystalline morphology or molecular orientation. Here the concept of biomimetic nanofibrillation, by copying the spiders’ spinning principles, was conceived to build silk-mimicking hierarchies in two-phase biodegradable blends, strategically involving the stepwise integration of elongational shear and high-pressure shear. Phase separation confined on nanoscale, together with deformation of discrete phases and pre-alignment of polymer chains, was triggered in the elongational shear, conferring the readiness for direct nanofibrillation in the latter shearing stage. The orderly aligned nanofibrils, featuring an ultralow diameter of around 100 nm and the “rigid−soft” system crosslinked by nanocrystal domains like silk protein dopes, were secreted by fine nanochannels. The incorporation of multiscale silk-mimicking structures afforded exceptional combination of strength, ductility and toughness for the nanofibrillar polymer composites. The proposed spider spinning-mimicking strategy, offering the biomimetic function integration unattainable with current approaches, may prompt materials scientists to pursue biopolymer mimics of silk with high performance yet light weight. PMID:27694989

Second-Sphere Effects in Dinuclear FeIIIZnII Hydrolase Biomimetics: Tuning Binding and Reactivity Properties.

PubMed

Camargo, Tiago Pacheco; Neves, Ademir; Peralta, Rosely A; Chaves, Cláudia; Maia, Elene C P; Lizarazo-Jaimes, Edgar H; Gomes, Dawidson A; Bortolotto, Tiago; Norberto, Douglas R; Terenzi, Hernán; Tierney, David L; Schenk, Gerhard

2018-01-02

Herein, we report the synthesis and characterization of two dinuclear Fe III Zn II complexes [Fe III Zn II LP1] (1) and [Fe III Zn II LP2] (2), in which LP1 and LP2 are conjugated systems containing one and two pyrene groups, respectively, connected via the diamine -HN(CH 2 ) 4 NH- spacer to the well-known N 5 O 2 -donor H 2 L ligand (H 2 L = 2-bis{[(2-pyridylmethyl)aminomethyl]-6-[(2-hydroxybenzyl)(2-pyridylmethyl)]aminomethyl}-4-methylphenol). The complex [Fe III Zn II L1] (3), in which H 2 L was modified to H 2 L1, with a carbonyl group attached to the terminal phenol group, was included in this study for comparison purposes. 1 Both complexes 1 and 2 were satisfactorily characterized in the solid state and in solution. Extended X-ray absorption fine structure data for 1 and 3 in an acetonitrile solution show that the multiply bridged structure seen in the solid state of 3 is retained in solution. Potentiometric and UV-vis titration of 1 and 2 show that electrostatic interaction between the protonated amino groups and coordinated water molecules significantly decreases the pK a of the iron(III)-bound water compared to those of 3. On the other hand, catalytic activity studies using 1 and 2 in the hydrolysis of the activated substrate bis(2,4-dinitrophenyl)phosphate (BDNPP) resulted in a significant increase in the association of the substrate (K ass ≅ 1/K M ) compared to that of 3 because of electrostatic and hydrophobic interactions between BDNPP and the side-chain diaminopyrene of the ligands H 2 LP1 and H 2 LP2. In addition, the introduction of the pyrene motifs in 1 and 2 enhanced their activity toward DNA and as effective antitumor drugs, although the biochemical mechanism of the latter effect is currently under investigation. These complexes represent interesting examples of how to promote an increase in the activity of traditional artificial metal nucleases by introducing second-coordination-sphere effects.

Biomimetic Production of Hydrogen

NASA Astrophysics Data System (ADS)

Gust, Devens

2004-03-01

The basic reaction for hydrogen generation is formation of molecular hydrogen from two electrons and two protons. Although there are many possible sources for the protons and electrons, and a variety of mechanisms for providing the requisite energy for hydrogen synthesis, the most abundant and readily available source of protons and electrons is water, and the most attractive source of energy for powering the process is sunlight. Not surprisingly, living systems have evolved to take advantage of these sources for materials and energy. Thus, biology provides paradigms for carrying out the reactions necessary for hydrogen production. Photosynthesis in green plants uses sunlight as the source of energy for the oxidation of water to give molecular oxygen, protons, and reduction potential. Some photosynthetic organisms are capable of using this reduction potential, in the form of the reduced redox protein ferredoxin, to reduce protons and produce molecular hydrogen via the action of an hydrogenase enzyme. A variety of other organisms metabolize the reduced carbon compounds that are ultimately the major products of photosynthesis to produce molecular hydrogen. These facts suggest that it might be possible to use light energy to make molecular hydrogen via biomimetic constructs that employ principles similar to those used by natural organisms, or perhaps with hybrid "bionic" systems that combine biomimetic materials with natural enzymes. It is now possible to construct artificial photosynthetic systems that mimic some of the major steps in the natural process.(1) Artificial antennas based on porphyrins, carotenoids and other chromophores absorb light at various wavelengths in the solar spectrum and transfer the harvested excitation energy to artificial photosynthetic reaction centers.(2) In these centers, photoinduced electron transfer uses the energy from light to move an electron from a donor to an acceptor moiety, generating a high-energy charge-separated state

Enhanced thermal shock resistance of ceramics through biomimetically inspired nanofins.

PubMed

Song, Fan; Meng, Songhe; Xu, Xianghong; Shao, Yingfeng

2010-03-26

We propose here a new method to make ceramics insensitive to thermal shock up to their melting temperature. In this method the surface of ceramics was biomimetically roughened into nanofinned surface that creates a thin air layer enveloping the surface of the ceramics during quenching. This air layer increases the heat transfer resistance of the surface of the ceramics by about 10,000 times so that the strong thermal gradient and stresses produced by the steep temperature difference in thermal shock did not occur both on the actual surface and in the interior of the ceramics. This method effectively extends the applications of existing ceramics in the extreme thermal environments.

Renewable Molecular Flasks with NADH Models: Combination of Light-Driven Proton Reduction and Biomimetic Hydrogenation of Benzoxazinones.

PubMed

Zhao, Liang; Wei, Jianwei; Lu, Junhua; He, Cheng; Duan, Chunying

2017-07-17

Using small molecules with defined pockets to catalyze chemical transformations resulted in attractive catalytic syntheses that echo the remarkable properties of enzymes. By modulating the active site of a nicotinamide adenine dinucleotide (NADH) model in a redox-active molecular flask, we combined biomimetic hydrogenation with in situ regeneration of the active site in a one-pot transformation using light as a clean energy source. This molecular flask facilitates the encapsulation of benzoxazinones for biomimetic hydrogenation of the substrates within the inner space of the flask using the active sites of the NADH models. The redox-active metal centers provide an active hydrogen source by light-driven proton reduction outside the pocket, allowing the in situ regeneration of the NADH models under irradiation. This new synthetic platform, which offers control over the location of the redox events, provides a regenerating system that exhibits high selectivity and efficiency and is extendable to benzoxazinone and quinoxalinone systems. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomimetic materials for controlling bone cell responses.

PubMed

Drevelle, Olivier; Faucheux, Nathalie

2013-01-01

Bone defects that cannot "heal spontaneously during life" will become an ever greater health problem as populations age. Harvesting autografts has several drawbacks, such as pain and morbidity at both donor and acceptor sites, the limited quantity of material available, and frequently its inappropriate shape. Researchers have therefore developed alternative strategies that involve biomaterials to fill bone defects. These biomaterials must be biocompatible and interact with the surrounding bone tissue to allow their colonization by bone cells and blood vessels. The latest generation biomaterials are not inert; they control cell responses like adhesion, proliferation and differentiation. These biomaterials are called biomimetic materials. This review focuses on the development of third generation materials. We first briefly describe the bone tissue with its cells and matrix, and then how bone cells interact with the extracellular matrix. The next section covers the materials currently used to repair bone defects. Finally, we describe the strategies employed to modify the surface of materials, such as coating with hydroxyapatite and grafting biomolecules.

Application of biomimetics in x-ray optics

NASA Astrophysics Data System (ADS)

Hudec, R.; Remisova, K.

2017-05-01

The principles of biomimetics were successfully applied in X ray optics in the past and recently, e.g. in Lobster-Eye optical systems. However, the recent growing knowledge of sea vision, especially of peculiar mirror eyes of scallops, crustaceans, and deep sea fishes, makes it possible to consider other such applications. One of the most important discoveries is finding of mirror eyes in deep sea fish Dolichopteryx longipes based on large large numbers of very small mirror plates organized in specific positions. This arrangement may even include principles of active optics. We report on ongoing study with focus on understanding of very specific mirror eyes of sea animals and how they may help us to design and develop special optics for scientific applications. We study the ways these mirror eyes work, what are the advantages of these peculiar eye arrangements, and whether these optics can be used in advanced devices, e. g. X-ray optics. We will briefly present and discuss the preliminary results.

[Biomimetic nanohydroxyapatite/gelatin composite material preparation and in vitro study].

PubMed

Li, Siriguleng; Hu, Xiaowen

2014-09-01

To prepare nHA/gelatin porous scaffold and to evaluate its physical and chemical properties and biocompatibility. We used nano-powders of HA and gelatin to prepare 3D porous composite scaffold by freeze-drying technique, and used scanning electron microscope, fourier transform infrared spectroscopy and universal testing machine to characterize the composite material. Osteoblasts were primarily cultured, and the third-passage osteoblasts were co-cultured with the composite material. The cell adhesion and morphology were examined under scanning electron microscope. The cell viability analysis was performed by MTT assay, and the alkaline phosphatase activity was measured with alkaline phosphatase kit. Scanning electron microscope showed that the scaffold possessed a 3-dimensional interconnected homogenous porous structure with pore sizes ranging from 150 to 400 μm. Fourier transform infrared spectroscopy showed that the composite material had a strong chemical bond between the inorganic phase and organic phase. The scaffold presented the compressive strength of (3.28 ± 0.51) MPa and porosities of (80.6 ± 4.1)%. Composite materials showed features of had good biocompatibility. Mouse osteoblasts were well adhered and spread on the materials. The grade of the cell toxicity ranged from I to II. On the 5th and 7th day the proliferative rate of osteoblasts on scaffolds in the composite materials was significantly higher than that in the control group. The activity of alkaline phosphatase was obviously higher than that in the control group on Day 1 and 3. Nano-hydroxyapatite and gelatin in certain proportions and under certain conditions can be prepared into a composite biomimetic porous scaffolds with high porosity and three-dimensional structure using freeze-drying method. The scaffold shows good biocompatibility with mouse osteoblasts and may be a novel scaffolds for bone tissue engineering.

Micromotor-Based Biomimetic Carbon Dioxide Sequestration: Towards Mobile Microscrubbers.

PubMed

Uygun, Murat; Singh, Virendra V; Kaufmann, Kevin; Uygun, Deniz A; de Oliveira, Severina D S; Wang, Joseph

2015-10-26

We describe a mobile CO2 scrubbing platform that offers a greatly accelerated biomimetic sequestration based on a self-propelled carbonic anhydrase (CA) functionalized micromotor. The CO2 hydration capability of CA is coupled with the rapid movement of catalytic micromotors, and along with the corresponding fluid dynamics, results in a highly efficient mobile CO2 scrubbing microsystem. The continuous movement of CA and enhanced mass transport of the CO2 substrate lead to significant improvements in the sequestration efficiency and speed over stationary immobilized or free CA platforms. This system is a promising approach to rapid and enhanced CO2 sequestration platforms for addressing growing concerns over the buildup of greenhouse gas. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomimetics, color, and the arts

NASA Astrophysics Data System (ADS)

Schenk, Franziska

2015-03-01

Color as dramatic, dynamic and dazzling as the iridescent hues on the wings of certain butterflies has never been encountered in the art world. Unlike and unmatched by the chemical pigments of the artists' palette, this changeable color is created by transparent, colorless nanostructures that, as with prisms, diffract and reflect light to render spectral color visible. Until now, iridescent colors, by their very nature, have defied artists' best efforts to fully capture these rainbow hues. Now, for the first time, the artist and researcher Franziska Schenk employs latest nature-inspired color-shift technology to actually simulate the iridescence of butterflies and beetles on canvas. Crucially, studying the ingenious ways in which a range of such displays are created by insects has provided the artist with vital clues on how to adapt and adopt these challenging optical nano-materials for painting. And indeed, after years of meticulous and painstaking research both in the lab and studio, the desired effect is achieved. The resulting paintings, like an iridescent insect, do in fact fluctuate in perceived color - depending on the light and viewing angle. In tracing the artist's respective biomimetic approach, the paper not only provides an insight into the new color technology's evolution and innovative artistic possibilities, but also suggests what artists can learn from nature.

Compressive failure modes and parameter optimization of the trabecular structure of biomimetic fully integrated honeycomb plates.

PubMed

Chen, Jinxiang; Tuo, Wanyong; Zhang, Xiaoming; He, Chenglin; Xie, Juan; Liu, Chang

2016-12-01

To develop lightweight biomimetic composite structures, the compressive failure and mechanical properties of fully integrated honeycomb plates were investigated experimentally and through the finite element method. The results indicated that: fracturing of the fully integrated honeycomb plates primarily occurred in the core layer, including the sealing edge structure. The morphological failures can be classified into two types, namely dislocations and compactions, and were caused primarily by the stress concentrations at the interfaces between the core layer and the upper and lower laminations and secondarily by the disordered short-fiber distribution in the material; although the fully integrated honeycomb plates manufactured in this experiment were imperfect, their mass-specific compressive strength was superior to that of similar biomimetic samples. Therefore, the proposed bio-inspired structure possesses good overall mechanical properties, and a range of parameters, such as the diameter of the transition arc, was defined for enhancing the design of fully integrated honeycomb plates and improving their compressive mechanical properties. Copyright © 2016 Elsevier B.V. All rights reserved.

Redox-Responsive Biomimetic Polymeric Micelle for Simultaneous Anticancer Drug Delivery and Aggregation-Induced Emission Active Imaging.

PubMed

Hu, Jun; Zhuang, Weihua; Ma, Boxuan; Su, Xin; Yu, Tao; Li, Gaocan; Hu, Yanfei; Wang, Yunbing

2018-05-10

Intelligent polymeric micelles have been developed as potential nanoplatforms for efficient drug delivery and diagnosis. Herein, we successfully prepared redox-sensitive polymeric micelles combined aggregation-induced emission (AIE) imaging as an outstanding anticancer drug carrier system for simultaneous chemotherapy and bioimaging. The amphiphilic copolymer TPE-SS-PLAsp- b-PMPC could self-assemble into spherical micelles, and these biomimetic micelles exhibited great biocompatibility and remarkable ability in antiprotein adsorption, showing great potential for biomedical application. Anticancer drug doxorubicin (DOX) could be encapsulated during the self-assembly process, and these drug-loaded micelles showed intelligent drug release and improved antitumor efficacy due to the quick disassembly in response to high levels of glutathione (GSH) in the environment. Moreover, the intracellular DOX release could be traced through the fluorescent imaging of these AIE micelles. As expected, the in vivo antitumor study exhibited that these DOX-carried micelles showed better antitumor efficacy and less adverse effects than that of free DOX. These results strongly indicated that this smart biomimetic micelle system would be a prominent candidate for chemotherapy and bioimaging.

Biomimetic collagen/elastin meshes for ventral hernia repair in a rat model.

PubMed

Minardi, Silvia; Taraballi, Francesca; Wang, Xin; Cabrera, Fernando J; Van Eps, Jeffrey L; Robbins, Andrew B; Sandri, Monica; Moreno, Michael R; Weiner, Bradley K; Tasciotti, Ennio

2017-03-01

Ventral hernia repair remains a major clinical need. Herein, we formulated a type I collagen/elastin crosslinked blend (CollE) for the fabrication of biomimetic meshes for ventral hernia repair. To evaluate the effect of architecture on the performance of the implants, CollE was formulated both as flat sheets (CollE Sheets) and porous scaffolds (CollE Scaffolds). The morphology, hydrophylicity and in vitro degradation were assessed by SEM, water contact angle and differential scanning calorimetry, respectively. The stiffness of the meshes was determined using a constant stretch rate uniaxial tensile test, and compared to that of native tissue. CollE Sheets and Scaffolds were tested in vitro with human bone marrow-derived mesenchymal stem cells (h-BM-MSC), and finally implanted in a rat ventral hernia model. Neovascularization and tissue regeneration within the implants was evaluated at 6weeks, by histology, immunofluorescence, and q-PCR. It was found that CollE Sheets and Scaffolds were not only biomechanically sturdy enough to provide immediate repair of the hernia defect, but also promoted tissue restoration in only 6weeks. In fact, the presence of elastin enhanced the neovascularization in both sheets and scaffolds. Overall, CollE Scaffolds displayed mechanical properties more closely resembling those of native tissue, and induced higher gene expression of the entire marker genes tested, associated with de novo matrix deposition, angiogenesis, adipogenesis and skeletal muscles, compared to CollE Sheets. Altogether, this data suggests that the improved mechanical properties and bioactivity of CollE Sheets and Scaffolds make them valuable candidates for applications of ventral hernia repair. Due to the elevated annual number of ventral hernia repair in the US, the lack of successful grafts, the design of innovative biomimetic meshes has become a prime focus in tissue engineering, to promote the repair of the abdominal wall, avoid recurrence. Our meshes (Coll

Biomimetic-inspired joining of composite with metal structures: A survey of natural joints and application to single lap joints

NASA Astrophysics Data System (ADS)

Avgoulas, Evangelos Ioannis; Sutcliffe, Michael P. F.

2014-03-01

Joining composites with metal parts leads, inevitably, to high stress concentrations because of the material property mismatch. Since joining composite to metal is required in many high performance structures, there is a need to develop a new multifunctional approach to meet this challenge. This paper uses the biomimetics approach to help develop solutions to this problem. Nature has found many ingenious ways of joining dissimilar materials and making robust attachments, alleviating potential stress concentrations. A literature survey of natural joint systems has been carried out, identifying and analysing different natural joint methods from a mechanical perspective. A taxonomy table was developed based on the different methods/functions that nature successfully uses to attach dissimilar tissues (materials). This table is used to understand common themes or approaches used in nature for different joint configurations and functionalities. One of the key characteristics that nature uses to joint dissimilar materials is a transitional zone of stiffness in the insertion site. Several biomimetic-inspired metal-to-composite (steel-to-CFRP), adhesively bonded, Single Lap Joints (SLJs) were numerically investigated using a finite element analysis. The proposed solutions offer a transitional zone of stiffness of one joint part to reduce the material stiffness mismatch at the joint. An optimisation procedure was used to identify the variation in material stiffness which minimises potential failure of the joint. It was found that the proposed biomimetic SLJs reduce the asymmetry of the stress distribution along the adhesive area.

Studying large jellyfish swimming hydrodynamics using a biomimetic robot named Cyro 2

NASA Astrophysics Data System (ADS)

Stewart, Colin; Krummel, Gregory; Villanueva, Alex; Marut, Kenneth; Priya, Shashank

2015-11-01

Some species of jellyfish can grow to great sizes, such as the lion's mane jellyfish (Cyanea capillata), which can span 2 m in diameter with tentacles 30 m long, roughly the same length as a blue whale. This is an impressive feat for an animal that begins its mobile life three orders of magnitude smaller. Such growth can require a large energy budget, suggesting that Cyanea may be a uniquely efficient swimmer, successful predator, or both. Either accolade would stem from a high level of hydrodynamic mastery as oblate jellyfish like Cyanea rely on the flow currents generated by bell pulsation for both propulsive thrust and prey encounter. However, further investigation has been hindered by the lack of reported quantitative flow measurements, perhaps due to the logistic challenges inherent to studying large specimen in vivo. Here, we used a 50 cm diameter biomimetic Cyanea robot named Cyro 2 as a proxy to study the hydrodynamics of large jellyfish. The effect of different trailing structure morphologies (e.g. oral arms and tentacles), swimming gaits, and kinematics on flow patterns were measured using PIV. Baseline swimming performance using biomimetic settings (but no trailing structures) was characterized by a cycle average velocity of 6.58 cm s-1, thrust of 1.9 N, and power input of 5.7 W, yielding a vehicle efficiency of 2.2% and a cost of transport of 15.4 J kg-1 m-1.

Engineering nanomaterials with a combined electrochemical and molecular biomimetic approach

NASA Astrophysics Data System (ADS)

Dai, Haixia

Biocomposite materials, such as bones, teeth, and shells, are created using mild aqueous solution-based processes near room temperature. Proteins add flexibility to these processes by facilitating the nucleation, growth, and ordering of specific inorganic materials into hierarchical structures. We aim to develop a biomimetic strategy for engineering technologically relevant inorganic materials with controlled compositions and structures, as Nature does, using proteins to orchestrate material formation and assembly. This approach involves three basic steps: (i) preparation of inorganic substrates compatible with combinatorial polypeptide screening; (ii) identification of inorganic-binding polypeptides and their engineering into inorganic-binding proteins; and (iii) protein-mediated inorganic nucleation and organization. Cuprous oxide (Cu2O), a p-type semiconductor, has been used to demonstrate all three steps. Zinc oxide (ZnO), an n-type semiconductor, has been used to show the generality of selected steps. Step (i), preparation of high quality inorganic substrates to select inorganic-binding polypeptides, was accomplished using electrochemical microfabrication to grow and pattern Cu2O and ZnO. Raman spectroscopy and x-ray photoelectron spectroscopy were used to verify phase purity and compositional stability of these surfaces during polypeptide screening. Step (ii), accomplished in collaboration with personnel in Prof Baneyx' lab at the University of Washington, involved incubating the inorganic substrates with the FliTrx(TM) random peptide library to identify cysteine-constrained dodecapeptides that bind the targeted inorganic. Insertion of a Cu2O-binding dodecapeptide into the DNA-binding protein TraI endowed the engineered TraI with strong affinity for Cu2O (Kd ≈ 10 -8 M). Finally, step (iii) involved nonequilibrium synthesis and organization of Cu2O nanoparticles, taking advantage of the inorganic and DNA recognition properties of the engineered TraI. The

Fabrication and Characterization of Biomimetic Collagen-Apatite Scaffolds with Tunable Structures for Bone Tissue Engineering

PubMed Central

Xia, Zengmin; Yu, Xiaohua; Jiang, Xi; Brody, Harold D; Rowe, David W; Wei, Mei

2013-01-01

The objective of the current study is to prepare a biomimetic collagen-apatite (Col-Ap) scaffold for improved bone repair and regeneration. A novel bottom-up approach has been developed, which combines a biomimetic self-assembly method with a controllable freeze casting technology. In this study, the mineralized collagen fibers were generated using a simple one-step co-precipitation method which involved collagen self-assembly and in situ apatite precipitation in a collagen-containing modified simulated body fluid (m-SBF). The precipitates were subjected to controllable freeze casting, forming scaffolds with either an isotropic equiaxed structure or a unidirectional lamellar structure. These scaffolds were comprised of collagen fibers and poorly crystalline bone-like carbonated apatite nanoparticles. The mineral content in the scaffold could be tailored in a range 0–54 wt% by simply adjusting the collagen content in the m-SBF. Further, the mechanisms of the formation of both the equiaxed and the lamellar scaffolds were investigated, and freezing regimes for equiaxed and lamellar solidification were established. Finally, bone forming capability of such prepared scaffolds was evaluated in vivo in a mouse calvarial defect model. It was confirmed that the scaffolds well support new bone formation. PMID:23567944

3D-Printed Biomimetic Super-Hydrophobic Structure for Microdroplet Manipulation and Oil/Water Separation.

PubMed

Yang, Yang; Li, Xiangjia; Zheng, Xuan; Chen, Zeyu; Zhou, Qifa; Chen, Yong

2018-03-01

Biomimetic functional surfaces are attracting increasing attention for various technological applications, especially the superhydrophobic surfaces inspired by plant leaves. However, the replication of the complex hierarchical microstructures is limited by the traditional fabrication techniques. In this paper, superhydrophobic micro-scale artificial hairs with eggbeater heads inspired by Salvinia molesta leaf was fabricated by the Immersed surface accumulation three dimensional (3D) printing process. Multi-walled carbon nanotubes were added to the photocurable resins to enhance the surface roughness and mechanical strength of the microstructures. The 3D printed eggbeater surface reveals interesting properties in terms of superhydrophobilicity and petal effect. The results show that a hydrophilic material can macroscopically behave as hydrophobic if a surface has proper microstructured features. The controllable adhesive force (from 23 μN to 55 μN) can be easily tuned with different number of eggbeater arms for potential applications such as micro hand for droplet manipulation. Furthermore, a new energy-efficient oil/water separation solution based on our biomimetic structures was demonstrated. The results show that the 3D-printed eggbeater structure could have numerous applications, including water droplet manipulation, 3D cell culture, micro reactor, oil spill clean-up, and oil/water separation. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomimetic HDL nanoparticle mediated tumor targeted delivery of indocyanine green for enhanced photodynamic therapy.

PubMed

Wang, Yazhe; Wang, Cheng; Ding, Yang; Li, Jing; Li, Min; Liang, Xiao; Zhou, Jianping; Wang, Wei

2016-12-01

Photodynamic therapy has emerged as a promising strategy for cancer treatment. To ensure the efficient delivery of a photosensitizer to tumor for anticancer effect, a safe and tumor-specific delivery system is highly desirable. Herein, we introduce a novel biomimetic nanoparticle named rHDL/ICG (rHDL/I), by loading amphiphilic near-infrared (NIR) fluorescent dye indocyanine green (ICG) into reconstituted high density lipoproteins (rHDL). In this system, rHDL can mediate photoprotection effect and receptor-guided tumor-targeting transportation of cargos into cells. Upon NIR irradiation, ICG can generate fluorescent imaging signals for diagnosis and monitoring therapeutic activity, and produce singlet oxygen to trigger photodynamic therapy (PDT). Our studies demonstrated that rHDL/I exhibited excellent size and fluorescence stability, light-triggered controlled release feature, and neglectable hemolytic activity. It also showed equivalent NIR response compared to free ICG under laser irradiation. Importantly, the fluorescent signal of ICG loaded in rHDL/I could be visualized subcellularly in vitro and exhibited metabolic distribution in vivo, presenting superior tumor targeting and internalization. This NIR-triggered image-guided nanoparticle produced outstanding therapeutic outcomes against cancer cells, demonstrating great potential of biomimetic delivery vehicles in future clinical practice. Copyright © 2016 Elsevier B.V. All rights reserved.

Biomimetics on seed dispersal: survey and insights for space exploration.

PubMed

Pandolfi, Camilla; Izzo, Dario

2013-06-01

Seeds provide the vital genetic link and dispersal agent between successive generations of plants. Without seed dispersal as a means of reproduction, many plants would quickly die out. Because plants lack any sort of mobility and remain in the same spot for their entire lives, they rely on seed dispersal to transport their offspring throughout the environment. This can be accomplished either collectively or individually; in any case as seeds ultimately abdicate their movement, they are at the mercy of environmental factors. Thus, seed dispersal strategies are characterized by robustness, adaptability, intelligence (both behavioral and morphological), and mass and energy efficiency (including the ability to utilize environmental sources of energy available): all qualities that advanced engineering systems aim at in general, and in particular those that need to enable complex endeavors such as space exploration. Plants evolved and adapted their strategy according to their environment, and taken together, they enclose many desirable characteristics that a space mission needs to have. Understanding in detail how plants control the development of seeds, fabricate structural components for their dispersal, build molecular machineries to keep seeds dormant up to the right moment and monitor the environment to release them at the right time could provide several solutions impacting current space mission design practices. It can lead to miniaturization, higher integration and packing efficiency, energy efficiency and higher autonomy and robustness. Consequently, there would appear to be good reasons for considering biomimetic solutions from plant kingdom when designing space missions, especially to other celestial bodies, where solid and liquid surfaces, atmosphere, etc constitute and are obviously parallel with the terrestrial environment where plants evolved. In this paper, we review the current state of biomimetics on seed dispersal to improve space mission design.

Preparation of monolithic silica-chitin composite under extreme biomimetic conditions.

PubMed

Bazhenov, Vasilii V; Wysokowski, Marcin; Petrenko, Iaroslav; Stawski, Dawid; Sapozhnikov, Philipp; Born, René; Stelling, Allison L; Kaiser, Sabine; Jesionowski, Teofil

2015-05-01

Chitin is a widespread renewable biopolymer that is extensively distributed in the natural world. The high thermal stability of chitin provides an opportunity to develop novel inorganic-organic composites under hydrothermal synthesis conditions in vitro. For the first time, in this work we prepared monolithic silica-chitin composite under extreme biomimetic conditions (80°C and pH 1.5) using three dimensional chitinous matrices isolated from the marine sponge Aplysina cauliformis. The resulting material was studied using light and fluorescence microscopy, scanning electron microscopy, Fourier transform infrared spectroscopy. A mechanism for the silica-chitin interaction after exposure to these hydrothermal conditions is proposed and discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Recent advances in biomimetic sensing technologies.

PubMed

Johnson, E A C; Bonser, R H C; Jeronimidis, G

2009-04-28

The importance of biological materials has long been recognized from the molecular level to higher levels of organization. Whereas, in traditional engineering, hardness and stiffness are considered desirable properties in a material, biology makes considerable and advantageous use of softer, more pliable resources. The development, structure and mechanics of these materials are well documented and will not be covered here. The purpose of this paper is, however, to demonstrate the importance of such materials and, in particular, the functional structures they form. Using only a few simple building blocks, nature is able to develop a plethora of diverse materials, each with a very different set of mechanical properties and from which a seemingly impossibly large number of assorted structures are formed. There is little doubt that this is made possible by the fact that the majority of biological 'materials' or 'structures' are based on fibres and that these fibres provide opportunities for functional hierarchies. We show how these structures have inspired a new generation of innovative technologies in the science and engineering community. Particular attention is given to the use of insects as models for biomimetically inspired innovations.

Biomimetic micromechanical adaptive flow-sensor arrays

NASA Astrophysics Data System (ADS)

Krijnen, Gijs; Floris, Arjan; Dijkstra, Marcel; Lammerink, Theo; Wiegerink, Remco

2007-05-01

We report current developments in biomimetic flow-sensors based on flow sensitive mechano-sensors of crickets. Crickets have one form of acoustic sensing evolved in the form of mechanoreceptive sensory hairs. These filiform hairs are highly perceptive to low-frequency sound with energy sensitivities close to thermal threshold. In this work we describe hair-sensors fabricated by a combination of sacrificial poly-silicon technology, to form silicon-nitride suspended membranes, and SU8 polymer processing for fabrication of hairs with diameters of about 50 μm and up to 1 mm length. The membranes have thin chromium electrodes on top forming variable capacitors with the substrate that allow for capacitive read-out. Previously these sensors have been shown to exhibit acoustic sensitivity. Like for the crickets, the MEMS hair-sensors are positioned on elongated structures, resembling the cercus of crickets. In this work we present optical measurements on acoustically and electrostatically excited hair-sensors. We present adaptive control of flow-sensitivity and resonance frequency by electrostatic spring stiffness softening. Experimental data and simple analytical models derived from transduction theory are shown to exhibit good correspondence, both confirming theory and the applicability of the presented approach towards adaptation.

Precise and Arbitrary Deposition of Biomolecules onto Biomimetic Fibrous Matrices for Spatially Controlled Cell Distribution and Functions.

PubMed

Jia, Chao; Luo, Bowen; Wang, Haoyu; Bian, Yongqian; Li, Xueyong; Li, Shaohua; Wang, Hongjun

2017-09-01

Advances in nano-/microfabrication allow the fabrication of biomimetic substrates for various biomedical applications. In particular, it would be beneficial to control the distribution of cells and relevant biomolecules on an extracellular matrix (ECM)-like substrate with arbitrary micropatterns. In this regard, the possibilities of patterning biomolecules and cells on nanofibrous matrices are explored here by combining inkjet printing and electrospinning. Upon investigation of key parameters for patterning accuracy and reproducibility, three independent studies are performed to demonstrate the potential of this platform for: i) transforming growth factor (TGF)-β1-induced spatial differentiation of fibroblasts, ii) spatiotemporal interactions between breast cancer cells and stromal cells, and iii) cancer-regulated angiogenesis. The results show that TGF-β1 induces local fibroblast-to-myofibroblast differentiation in a dose-dependent fashion, and breast cancer clusters recruit activated stromal cells and guide the sprouting of endothelial cells in a spatially resolved manner. The established platform not only provides strategies to fabricate ECM-like interfaces for medical devices, but also offers the capability of spatially controlling cell organization for fundamental studies, and for high-throughput screening of various biomolecules for stem cell differentiation and cancer therapeutics. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomimetic approaches with smart interfaces for bone regeneration.

PubMed

Sailaja, G S; Ramesh, P; Vellappally, Sajith; Anil, Sukumaran; Varma, H K

2016-11-05

A 'smart tissue interface' is a host tissue-biomaterial interface capable of triggering favourable biochemical events inspired by stimuli responsive mechanisms. In other words, biomaterial surface is instrumental in dictating the interface functionality. This review aims to investigate the fundamental and favourable requirements of a 'smart tissue interface' that can positively influence the degree of healing and promote bone tissue regeneration. A biomaterial surface when interacts synergistically with the dynamic extracellular matrix, the healing process become accelerated through development of a smart interface. The interface functionality relies equally on bound functional groups and conjugated molecules belonging to the biomaterial and the biological milieu it interacts with. The essential conditions for such a special biomimetic environment are discussed. We highlight the impending prospects of smart interfaces and trying to relate the design approaches as well as critical factors that determine species-specific functionality with special reference to bone tissue regeneration.

Biomimetically Engineered Demi-Bacteria Potentiate Vaccination against Cancer.

PubMed

Ni, Dezhi; Qing, Shuang; Ding, Hui; Yue, Hua; Yu, Di; Wang, Shuang; Luo, Nana; Su, Zhiguo; Wei, Wei; Ma, Guanghui

2017-10-01

Failure in enhancing antigen immunogenicity has limited the development of cancer vaccine. Inspired by effective immune responses toward microorganisms, demi-bacteria (DB) from Bacillus are engineered as carriers for cancer vaccines. The explored hydrothermal treatment enables the Bacillus to preserve optimal pathogen morphology with intrinsic mannose receptor agonist. Meanwhile, the treated Bacillus can be further endowed with ideal hollow/porous structure for efficient accommodation of antigen and adjuvant, such as CpG. Therefore, this optimal engineered nanoarchitecture allows multiple immunostimulatory elements integrate in a pattern closely resembling that of bacterial pathogens. Such pathogen mimicry greatly enhances antigen uptake and cross-presentation, resulting in stronger immune activation suitable for cancer vaccines. Indeed, DB-based biomimetic vaccination in mice induces synergistic cellular and humoral immune responses, achieving potent therapeutic and preventive effects against cancer. Application of microorganism-sourced materials thus presents new opportunities for potent cancer therapy.

Biomimetically Engineered Demi‐Bacteria Potentiate Vaccination against Cancer

PubMed Central

Ni, Dezhi; Qing, Shuang; Ding, Hui; Yue, Hua; Yu, Di; Wang, Shuang; Luo, Nana; Su, Zhiguo

2017-01-01

Abstract Failure in enhancing antigen immunogenicity has limited the development of cancer vaccine. Inspired by effective immune responses toward microorganisms, demi‐bacteria (DB) from Bacillus are engineered as carriers for cancer vaccines. The explored hydrothermal treatment enables the Bacillus to preserve optimal pathogen morphology with intrinsic mannose receptor agonist. Meanwhile, the treated Bacillus can be further endowed with ideal hollow/porous structure for efficient accommodation of antigen and adjuvant, such as CpG. Therefore, this optimal engineered nanoarchitecture allows multiple immunostimulatory elements integrate in a pattern closely resembling that of bacterial pathogens. Such pathogen mimicry greatly enhances antigen uptake and cross‐presentation, resulting in stronger immune activation suitable for cancer vaccines. Indeed, DB‐based biomimetic vaccination in mice induces synergistic cellular and humoral immune responses, achieving potent therapeutic and preventive effects against cancer. Application of microorganism‐sourced materials thus presents new opportunities for potent cancer therapy. PMID:29051851

Biomimetic NMES controller for arm movements supported by a passive exoskeleton.

PubMed

Ferrante, S; Ambrosini, E; Ferrigno, G; Pedrocchi, A

2012-01-01

The European Project MUltimodal Neuroprosthesis for Daily Upper limb Support (MUNDUS) aims at the development of an assistive platform for recovering direct interaction capability during daily life activities based on arm reaching and hand functions. Within this project the present study is focused on the design of a biomimetic controller able to modulate the neuromuscular electrical stimulation needed to perform reaching movements supported by a commercial passive exoskeleton for weight relief. Once defined the activities of daily life to be supported by the MUNDUS system, an experimental campaign on healthy subjects was carried out to identify the repeatable kinematics and muscular solution adopted during the target movements. The kinematics resulted to be highly stereotyped, a root mean squared error lower than 5° was found between all the trajectories obtained by healthy subjects in the same movement. A principal component analysis was performed on the EMG signals: less than 5 components explained more than the 85% of the signal variance. This result suggested that the muscular strategy adopted by healthy subjects was stereotyped and can be replicated by a biomimetic NMES controller. The controller was based on a time-delay artificial neural network which mapped the dynamic and non-linear relationship between kinematics and EMG activations to determine the stimulation timing. The stimulation levels reproduced the same scaling factors found between muscles in the stereotyped strategy. The controller was tested on 2 healthy subjects and though it was a feedforward controller, it showed good accuracy in reaching the desired target positions. The integration of a feedback controller is foreseen to ensure the complete accomplishment of the task and to compensate for unpredictable conditions such as muscular fatigue.

Biomimetic composite coating on rapid prototyped scaffolds for bone tissue engineering.

PubMed

Arafat, M Tarik; Lam, Christopher X F; Ekaputra, Andrew K; Wong, Siew Yee; Li, Xu; Gibson, Ian

2011-02-01

The objective of this present study was to improve the functional performance of rapid prototyped scaffolds for bone tissue engineering through biomimetic composite coating. Rapid prototyped poly(ε-caprolactone)/tri-calcium phosphate (PCL/TCP) scaffolds were fabricated using the screw extrusion system (SES). The fabricated PCL/TCP scaffolds were coated with a carbonated hydroxyapatite (CHA)-gelatin composite via biomimetic co-precipitation. The structure of the prepared CHA-gelatin composite coating was studied by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Compressive mechanical testing revealed that the coating process did not have any detrimental effect on the mechanical properties of the scaffolds. The cell-scaffold interaction was studied by culturing porcine bone marrow stromal cells (BMSCs) on the scaffolds and assessing the proliferation and bone-related gene and protein expression capabilities of the cells. Confocal laser microscopy and SEM images of the cell-scaffold constructs showed a uniformly distributed cell sheet and accumulation of extracellular matrix in the interior of CHA-gelatin composite-coated PCL/TCP scaffolds. The proliferation rate of BMSCs on CHA-gelatin composite-coated PCL/TCP scaffolds was about 2.3 and 1.7 times higher than that on PCL/TCP scaffolds and CHA-coated PCL/TCP scaffolds, respectively, by day 10. Furthermore, reverse transcription polymerase chain reaction and Western blot analysis revealed that CHA-gelatin composite-coated PCL/TCP scaffolds stimulate osteogenic differentiation of BMSCs the most, compared with PCL/TCP scaffolds and CHA-coated PCL/TCP scaffolds. These results demonstrate that CHA-gelatin composite-coated rapid prototyped PCL/TCP scaffolds are promising for bone tissue engineering. Copyright © 2010 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Calcium powered phloem protein of SEO gene family "Forisome" functions in wound sealing and act as biomimetic smart materials.

PubMed

Srivastava, Vineet Kumar; Tuteja, Narendra

2014-01-01

Forisomes protein belongs to SEO gene family and is unique to Fabaceae family. These proteins are located in sieve tubes of phloem and function to prevent loss of nutrient-rich photoassimilates, upon mechanical injury/wounding. Forisome protein is also known as ATP independent, mechanically active proteins. Despite the wealth of information role of forisome in plants are not yet fully understood. Recent reports suggest that forisomes protein can act as ideal model to study self assembly mechanism for development of nanotechnological devices like microfluidic system application in space exploration mission. Improvement in micro instrument is highly demanding and has been a key technology by NASA in future space exploration missions. Based on its physical parameters, forisome are found to be ideal biomimetic materials for micro fluidic system because the conformational shifts can be replicated in vitro and are fully reversible over large number of cycles. By the use of protein engineering forisome recombinant protein can be tailored. Due to its unique ability to convert chemical energy into mechanical energy forisome has received much attention. For nanotechnological application and handling biomolecules such as DNA, RNA, protein and cell as a whole microfluidic system will be the most powerful technology. The discovery of new biomimetic smart materials has been a key factor in development of space science and its requirements in such a challenging environment. The field of microfludic, particularly in terms of development of its components along with identification of new biomimetic smart materials, deserves more attention. More biophysical investigation is required to characterize it to make it more suitable under parameters of performance.

Calcium powered phloem protein of SEO gene family "Forisome" functions in wound sealing and act as biomimetic smart materials.

PubMed

Srivastava, Vineet Kumar; Tuteja, Narendra

2014-06-06

Forisomes protein belongs to SEO gene family and is unique to Fabaceae family. These proteins are located in sieve tubes of phloem and function to prevent loss of nutrient-rich photoassimilates, upon mechanical injury/wounding. Forisome protein is also known as ATP independent, mechanically active proteins. Despite the wealth of information role of forisome in plants are not yet fully understood. Recent reports suggest that forisomes protein can act as ideal model to study self assembly mechanism for development of nanotechnological devices like microfluidic system application in space exploration mission. Improvement in micro instrument is highly demanding and has been a key technology by NASA in future space exploration missions. Based on its physical parameters, forisome are found to be ideal biomimetic materials for micro fluidic system because the conformational shifts can be replicated in vitro and are fully reversible over large number of cycles. By the use of protein engineering forisome recombinant protein can be tailored. Due to its unique ability to convert chemical energy into mechanical energy forisome has received much attention. For nanotechnological application and handling biomolecules such as DNA, RNA, protein and cell as a whole microfluidic system will be the most powerful technology. The discovery of new biomimetic smart materials has been a key factor in development of space science and its requirements in such a challenging environment. The field of microfludic, particularly in terms of development of its components along with identification of new biomimetic smart materials, deserves more attention. More biophysical investigation is required to characterize it to make it more suitable under parameters of performance.

Imposed Thermal Fatigue and Post-Thermal-Cycle Wear Resistance of Biomimetic Gray Cast Iron by Laser Treatment

NASA Astrophysics Data System (ADS)

Sui, Qi; Zhou, Hong; Zhang, Deping; Chen, Zhikai; Zhang, Peng

2017-08-01

The present study aims to create coupling biomimetic units on gray cast iron substrate by laser surface treatment (LST). LSTs for single-step (LST1) and two-step (LST2) processes, were carried out on gray cast iron in different media (air and water). Their effects on microstructure, thermal fatigue, and post-thermal-cycle wear (PTW) resistance on the specimens were studied. The tests were carried out to examine the influence of crack-resistance behavior as well as the biomimetic surface on its post-thermal-cycle wear behavior and different units, with different laser treatments for comparison. Results showed that LST2 enhanced the PTW behaviors of gray cast iron, which then led to an increase in its crack resistance. Among the treated cast irons, the one treated by LST2 in air showed the lowest residual stress, due to the positive effect of the lower steepness of the thermal gradient. Moreover, the same specimen showed the best PTW performance, due to its superior crack resistance and higher hardness as a result of it.

Bioaccessibility of cadmium in fresh and cooked Agaricus blazei Murill assessed by in vitro biomimetic digestion system.

PubMed

Sun, Liping; Liu, Gaoxiang; Yang, Meizhizi; Zhuang, Yongliang

2012-05-01

Bioaccessibility of cadmium (Cd) in fresh and cooked Agaricus blazei Murill (AbM) was studied by an in vitro biomimetic digestion system in this paper. The results showed that the Cd content in fresh AbM was 10.27 mg kg(-1) DM. The cooking treatments of boiling and microwaving with water significantly decreased Cd contents in fresh AbM by 36.4% and 30.2% (P<0.05), respectively. Cd in fresh AbM showed the highest bioaccessibility of 77.8% during the biomimetic digestion in stomach, followed by that of 69.4% from the gastrointestinal digestion. Cooking treatments also significantly lowered the bioaccessibility of Cd (P<0.05). Cd in boiled AbM showed 50.7% and 46.1% bioaccessibility during the gastric and gastrointestinal procedures. While, Cd in microwaved AbM showed 58.2% and 50.4% bioaccessibility. This study confirmed that the health risk assessment of AbM depending on the total Cd levels in fresh AbM was inaccurate, especially for the products domestically cooked. Copyright © 2012 Elsevier Ltd. All rights reserved.

Real-time biomimetic Central Pattern Generators in an FPGA for hybrid experiments

PubMed Central

Ambroise, Matthieu; Levi, Timothée; Joucla, Sébastien; Yvert, Blaise; Saïghi, Sylvain

2013-01-01

This investigation of the leech heartbeat neural network system led to the development of a low resources, real-time, biomimetic digital hardware for use in hybrid experiments. The leech heartbeat neural network is one of the simplest central pattern generators (CPG). In biology, CPG provide the rhythmic bursts of spikes that form the basis for all muscle contraction orders (heartbeat) and locomotion (walking, running, etc.). The leech neural network system was previously investigated and this CPG formalized in the Hodgkin–Huxley neural model (HH), the most complex devised to date. However, the resources required for a neural model are proportional to its complexity. In response to this issue, this article describes a biomimetic implementation of a network of 240 CPGs in an FPGA (Field Programmable Gate Array), using a simple model (Izhikevich) and proposes a new synapse model: activity-dependent depression synapse. The network implementation architecture operates on a single computation core. This digital system works in real-time, requires few resources, and has the same bursting activity behavior as the complex model. The implementation of this CPG was initially validated by comparing it with a simulation of the complex model. Its activity was then matched with pharmacological data from the rat spinal cord activity. This digital system opens the way for future hybrid experiments and represents an important step toward hybridization of biological tissue and artificial neural networks. This CPG network is also likely to be useful for mimicking the locomotion activity of various animals and developing hybrid experiments for neuroprosthesis development. PMID:24319408

A Structurally and Functionally Biomimetic Biphasic Scaffold for Intervertebral Disc Tissue Engineering

PubMed Central

Choy, Andrew Tsz Hang; Chan, Barbara Pui

2015-01-01

Tissue engineering offers high hopes for the treatment of intervertebral disc (IVD) degeneration. Whereas scaffolds of the disc nucleus and annulus have been extensively studied, a truly biomimetic and mechanically functional biphasic scaffold using naturally occurring extracellular matrix is yet to be developed. Here, a biphasic scaffold was fabricated with collagen and glycosaminoglycans (GAGs), two of the most abundant extracellular matrix components in the IVD. Following fabrication, the scaffold was characterized and benchmarked against native disc. The biphasic scaffold was composed of a collagen-GAG co-precipitate making up the nucleus pulposus-like core, and this was encapsulated in multiple lamellae of photochemically crosslinked collagen membranes comprising the annulus fibrosus-like lamellae. On mechanical testing, the height of our engineered disc recovered by ~82-89% in an annulus-independent manner, when compared with the 99% recovery exhibited by native disc. The annulus-independent nature of disc height recovery suggests that the fluid replacement function of the engineered nucleus pulposus core might mimic this hitherto unique feature of native disc. Biphasic scaffolds comprised of 10 annulus fibrosus-like lamellae had the best overall mechanical performance among the various designs owing to their similarity to native disc in most aspects, including elastic compliance during creep and recovery, and viscous compliance during recovery. However, the dynamic mechanical performance (including dynamic stiffness and damping factor) of all the biphasic scaffolds was similar to that of the native discs. This study contributes to the rationalized design and development of a biomimetic and mechanically viable biphasic scaffold for IVD tissue engineering. PMID:26115332

Unusual multiscale mechanics of biomimetic nanoparticle hydrogels

DOE PAGES

Zhou, Yunlong; Damasceno, Pablo F.; Somashekar, Bagganahalli S.; ...

2018-01-12

Viscoelastic properties are central for gels and other materials. Simultaneously, high storage and loss moduli are difficult to attain due to their contrarian requirements to chemical structure. Biomimetic inorganic nanoparticles offer a promising toolbox for multiscale engineering of gel mechanics, but a conceptual framework for their molecular, nanoscale, mesoscale, and microscale engineering as viscoelastic materials is absent. Here we show nanoparticle gels with simultaneously high storage and loss moduli from CdTe nanoparticles. Viscoelastic figure of merit reaches 1.83 MPa exceeding that of comparable gels by 100–1000 times for glutathione-stabilized nanoparticles. The gels made from the smallest nanoparticles display the highestmore » stiffness, which was attributed to the drastic change of GSH configurations when nanoparticles decrease in size. A computational model accounting for the difference in nanoparticle interactions for variable GSH configurations describes the unusual trends of nanoparticle gel viscoelasticity. These observations are generalizable to other NP gels interconnected by supramolecular interactions and lead to materials with high-load bearing abilities and energy dissipation needed for multiple technologies.« less

Tubular inverse opal scaffolds for biomimetic vessels.

PubMed

Zhao, Ze; Wang, Jie; Lu, Jie; Yu, Yunru; Fu, Fanfan; Wang, Huan; Liu, Yuxiao; Zhao, Yuanjin; Gu, Zhongze

2016-07-14

There is a clinical need for tissue-engineered blood vessels that can be used to replace or bypass damaged arteries. The success of such grafts depends strongly on their ability to mimic native arteries; however, currently available artificial vessels are restricted by their complex processing, controversial integrity, or uncontrollable cell location and orientation. Here, we present new tubular scaffolds with specific surface microstructures for structural vessel mimicry. The tubular scaffolds are fabricated by rotationally expanding three-dimensional tubular inverse opals that are replicated from colloidal crystal templates in capillaries. Because of the ordered porous structure of the inverse opals, the expanded tubular scaffolds are imparted with circumferentially oriented elliptical pattern microstructures on their surfaces. It is demonstrated that these tailored tubular scaffolds can effectively make endothelial cells to form an integrated hollow tubular structure on their inner surface and induce smooth muscle cells to form a circumferential orientation on their outer surface. These features of our tubular scaffolds make them highly promising for the construction of biomimetic blood vessels.

Unusual multiscale mechanics of biomimetic nanoparticle hydrogels

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

Zhou, Yunlong; Damasceno, Pablo F.; Somashekar, Bagganahalli S.

Viscoelastic properties are central for gels and other materials. Simultaneously, high storage and loss moduli are difficult to attain due to their contrarian requirements to chemical structure. Biomimetic inorganic nanoparticles offer a promising toolbox for multiscale engineering of gel mechanics, but a conceptual framework for their molecular, nanoscale, mesoscale, and microscale engineering as viscoelastic materials is absent. Here we show nanoparticle gels with simultaneously high storage and loss moduli from CdTe nanoparticles. Viscoelastic figure of merit reaches 1.83 MPa exceeding that of comparable gels by 100–1000 times for glutathione-stabilized nanoparticles. The gels made from the smallest nanoparticles display the highestmore » stiffness, which was attributed to the drastic change of GSH configurations when nanoparticles decrease in size. A computational model accounting for the difference in nanoparticle interactions for variable GSH configurations describes the unusual trends of nanoparticle gel viscoelasticity. These observations are generalizable to other NP gels interconnected by supramolecular interactions and lead to materials with high-load bearing abilities and energy dissipation needed for multiple technologies.« less

Nano-mechanical properties and structural of a 3D-printed biodegradable biomimetic micro air vehicle wing

NASA Astrophysics Data System (ADS)

Salami, E.; Montazer, E.; Ward, T. A.; Ganesan, P. B.

2017-06-01

The biomimetic micro air vehicles (BMAV) are unmanned, micro-scaled aircraft that are bio-inspired from flying organisms to achieve the lift and thrust by flapping their wings. The main objectives of this study are to design a BMAV wing (inspired from the dragonfly) and analyse its nano-mechanical properties. In order to gain insights into the flight mechanics of dragonfly, reverse engineering methods were used to establish three-dimensional geometrical models of the dragonfly wings, so we can make a comparative analysis. Then mechanical test of the real dragonfly wings was performed to provide experimental parameter values for mechanical models in terms of nano-hardness and elastic modulus. The mechanical properties of wings were measured by nanoindentre. Finally, a simplified model was designed and the dragonfly-like wing frame structure was bio-mimicked and fabricated using a 3D printer. Then mechanical test of the BMAV wings was performed to analyse and compare the wings under a variety of simplified load regimes that are concentrated force, uniform line-load and a torque. This work opened up the possibility towards developing an engineering basis for the biomimetic design of BMAV wings.

Deuterohemin-Peptide Enzyme Mimic-Embedded Metal-Organic Frameworks through Biomimetic Mineralization with Efficient ATRP Catalytic Activity.

PubMed

Jiang, Wei; Wang, Xinghuo; Chen, Jiawen; Liu, Ying; Han, Haobo; Ding, Yi; Li, Quanshun; Tang, Jun

2017-08-16

An enzyme mimic harboring iron porphyrin (DhHP-6) embedded in zeolite imidazolate framework-8 (ZIF-8) was constructed through a biomimetic mineralization approach to obtain composite DhHP-6@ZIF-8. The composite was then used as a catalyst in the atom transfer radical polymerization (ATRP) of poly(ethylene glycol) methyl ether methacrylate (PEGMA 500 ) in which poly(PEGMA 500 ) could be synthesized with monomer conversion of 76.1% and M n of 45 900 g/mol, stronger than that obtained when using free DhHP-6 as a catalyst. More importantly, it could efficiently overcome the drawbacks of free DhHP-6 and achieve the easy separation of DhHP-6 from the catalytic system and the elimination of iron residues in the synthesized polymer. In addition, it exhibited an enhanced recyclability with monomer conversion of 75.7% after five cycles and favorable stability during the ATRP reaction with <3.0% of DhHP-6 release within 100 h. Thus, the enzyme mimic-ZIF-8 composite developed through biomimetic mineralization can be potentially used as an effective catalyst for preparing well-defined polymers with biomedical applications.

Fabrication and characterization of biomimetic collagen-apatite scaffolds with tunable structures for bone tissue engineering.

PubMed

Xia, Zengmin; Yu, Xiaohua; Jiang, Xi; Brody, Harold D; Rowe, David W; Wei, Mei

2013-07-01

The objective of the current study is to prepare a biomimetic collagen-apatite scaffold for improved bone repair and regeneration. A novel bottom-up approach has been developed, which combines a biomimetic self-assembly method with a controllable freeze-casting technology. In this study, the mineralized collagen fibers were generated using a simple one-step co-precipitation method which involved collagen self-assembly and in situ apatite precipitation in a collagen-containing modified simulated body fluid (m-SBF). The precipitates were then subjected to controllable freeze casting, forming scaffolds with either an isotropic equiaxed structure or a unidirectional lamellar structure. These scaffolds were comprised of collagen fibers and poorly crystalline bone-like carbonated apatite nanoparticles. The mineral content in the scaffold could be tailored in the range 0-54wt.% by simply adjusting the collagen content in the m-SBF. Further, the mechanisms of the formation of both the equiaxed and the lamellar scaffolds were investigated, and freezing regimes for equiaxed and lamellar solidification were established. Finally, the bone-forming capability of such prepared scaffolds was evaluated in vivo in a mouse calvarial defect model. It was confirmed that the scaffolds well support new bone formation. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Tumor-environment biomimetics delay peritoneal metastasis formation by deceiving and redirecting disseminated cancer cells.

PubMed

De Vlieghere, Elly; Gremonprez, Félix; Verset, Laurine; Mariën, Lore; Jones, Christopher J; De Craene, Bram; Berx, Geert; Descamps, Benedicte; Vanhove, Christian; Remon, Jean-Paul; Ceelen, Wim; Demetter, Pieter; Bracke, Marc; De Geest, Bruno G; De Wever, Olivier

2015-06-01

Peritoneal metastasis is life threatening and is the result of an extensive communication between disseminated cancer cells, mesothelial cells and cancer-associated fibroblasts (CAF). CAFs secrete extracellular matrix (ECM) proteins creating a receptive environment for peritoneal implantation. Considering cancer as an ecosystem may provide opportunities to exploit CAFs to create biomimetic traps to deceive and redirect cancer cells. We have designed microparticles (MP) containing a CAF-derived ECM-surface that is intended to compete with natural niches. CAFs were encapsulated in alginate/gelatine beads (500-750 μm in diameter) functionalised with a polyelectrolyte coating (MP[CAF]). The encapsulated CAFs remain viable and metabolically active (≥35 days), when permanently encapsulated. CAF-derived ECM proteins are retained by the non-biodegradable coating. Adhesion experiments mimicking the environment of the peritoneal cavity show the selective capture of floating cancer cells from different tumor origins by MP[CAF] compared to control MP. MP[CAF] are distributed throughout the abdominal cavity without attachment to intestinal organs and without signs of inflammatory reaction. Intraperitoneal delivery of MP[CAF] and sequential removal redirects cancer cell adhesion from the surgical wound to the MP[CAF], delays peritoneal metastasis formation and prolongs animal survival. Our experiments suggest the use of a biomimetic trap based on tumor-environment interactions to delay peritoneal metastasis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Evaluation of different crosslinking agents on hybrid biomimetic collagen-hydroxyapatite composites for regenerative medicine.

PubMed

Krishnakumar, Gopal Shankar; Gostynska, Natalia; Dapporto, Massimiliano; Campodoni, Elisabetta; Montesi, Monica; Panseri, Silvia; Tampieri, Anna; Kon, Elizaveta; Marcacci, Maurilio; Sprio, Simone; Sandri, Monica

2018-01-01

This study focuses on the development of novel bone-like scaffolds by bio-inspired, pH-driven, mineralization of type I collagen matrix with magnesium-doped hydroxyapatite nanophase (MgHA/Coll). To this aim, this study evaluates the altered modifications in the obtained composite due to different crosslinkers such as dehydrothermal treatment (DHT), 1,4-butanediol diglycidyl ether (BDDGE) and ribose in terms of morphological, physical-chemical and biological properties. The physical-chemical properties of the composites evaluated by XRD, FTIR, ICP and TGA demonstrated that the chemical mimesis of bone was effectively achieved using the in-lab biomineralization process. Furthermore, the presence of various crosslinkers greatly promoted beneficial enzymatic resistivity and swelling ability. The morphological results revealed highly porous and fibrous micro-architecture with total porosity above 85% with anisotropic pore size within the range of 50-200μm in all the analysed composites. The mechanical behaviour in response to compressive forces demonstrated enhanced compressive modulus in all crosslinked composites, suggesting that mechanical behaviour is largely dependent on the type of crosslinker used. The biomimetic compositional and morphological features of the composites elicited strong cell-material interaction. Therefore, the results showed that by activating specific crosslinking mechanisms, hybrid composites can be designed and tailored to develop tissue-specific biomimetic biomaterials for hard tissue engineering. Copyright © 2017 Elsevier B.V. All rights reserved.

Aquaporin-Based Biomimetic Polymeric Membranes: Approaches and Challenges

PubMed Central

Habel, Joachim; Hansen, Michael; Kynde, Søren; Larsen, Nanna; Midtgaard, Søren Roi; Jensen, Grethe Vestergaard; Bomholt, Julie; Ogbonna, Anayo; Almdal, Kristoffer; Schulz, Alexander; Hélix-Nielsen, Claus

2015-01-01

In recent years, aquaporin biomimetic membranes (ABMs) for water separation have gained considerable interest. Although the first ABMs are commercially available, there are still many challenges associated with further ABM development. Here, we discuss the interplay of the main components of ABMs: aquaporin proteins (AQPs), block copolymers for AQP reconstitution, and polymer-based supporting structures. First, we briefly cover challenges and review recent developments in understanding the interplay between AQP and block copolymers. Second, we review some experimental characterization methods for investigating AQP incorporation including freeze-fracture transmission electron microscopy, fluorescence correlation spectroscopy, stopped-flow light scattering, and small-angle X-ray scattering. Third, we focus on recent efforts in embedding reconstituted AQPs in membrane designs that are based on conventional thin film interfacial polymerization techniques. Finally, we describe some new developments in interfacial polymerization using polyhedral oligomeric silsesquioxane cages for increasing the physical and chemical durability of thin film composite membranes. PMID:26264033

Biomimetic whisker-shaped apatite coating of titanium powder.

PubMed

Sim, Young Uk; Kim, Jong Hee; Yang, Tae Young; Yoon, Seog Young; Park, Hong Chae

2010-05-01

Biomimetic apatite coatings on chemically modified titanium powder have been processed and the resulting coating layers evaluated in terms of morphology, composition and structure, using TF-XRD, XPS, SEM, TEM and FTIR analysis. After 7 days immersion in a simulated body fluid (SBF), nanometer-sized fine precipitates with an amorphous whisker-like phase and a Ca/P atomic ratio of 1.94 were obtained on the external surface of the titanium particles. When the immersion time in SBF was extended to 16 days, the coating layer consisted of the whisker-like nanostructured crystals of carbonated hydroxyapatite with a atomic ratio of 3; in such a case, a double coating layer was developed. The double layer could be divided into two regions and could be clearly distinguished: an inner dense region (approximately 200 nm in thickness) which may include hard agglomerated crystals and an outer less dense region (> 500 nm in thickness) in which crystals are loosely distributed.

Enzymatic hydrolysis of biomimetic bacterial cellulose-hemicellulose composites.

PubMed

Penttilä, Paavo A; Imai, Tomoya; Hemming, Jarl; Willför, Stefan; Sugiyama, Junji

2018-06-15

The production of biofuels and other chemicals from lignocellulosic biomass is limited by the inefficiency of enzymatic hydrolysis. Here a biomimetic composite material consisting of bacterial cellulose and wood-based hemicelluloses was used to study the effects of hemicelluloses on the enzymatic hydrolysis with a commercial cellulase mixture. Bacterial cellulose synthesized in the presence of hemicelluloses, especially xylan, was found to be more susceptible to enzymatic hydrolysis than hemicellulose-free bacterial cellulose. The reason for the easier hydrolysis could be related to the nanoscale structure of the substrate, particularly the packing of cellulose microfibrils into ribbons or bundles. In addition, small-angle X-ray scattering was used to show that the average nanoscale morphology of bacterial cellulose remained unchanged during the enzymatic hydrolysis. The reported easier enzymatic hydrolysis of bacterial cellulose produced in the presence of wood-based xylan offers new insights to overcome biomass recalcitrance through genetic engineering. Copyright © 2018 Elsevier Ltd. All rights reserved.

Silaffins in Silica Biomineralization and Biomimetic Silica Precipitation

PubMed Central

Lechner, Carolin C.; Becker, Christian F. W.

2015-01-01

Biomineralization processes leading to complex solid structures of inorganic material in biological systems are constantly gaining attention in biotechnology and biomedical research. An outstanding example for biomineral morphogenesis is the formation of highly elaborate, nano-patterned silica shells by diatoms. Among the organic macromolecules that have been closely linked to the tightly controlled precipitation of silica in diatoms, silaffins play an extraordinary role. These peptides typically occur as complex posttranslationally modified variants and are directly involved in the silica deposition process in diatoms. However, even in vitro silaffin-based peptides alone, with and without posttranslational modifications, can efficiently mediate biomimetic silica precipitation leading to silica material with different properties as well as with encapsulated cargo molecules of a large size range. In this review, the biomineralization process of silica in diatoms is summarized with a specific focus on silaffins and their in vitro silica precipitation properties. Applications in the area of bio- and nanotechnology as well as in diagnostics and therapy are discussed. PMID:26295401

A Biomimetic Algorithm for Flight Stabilization in Airborne Vehicles, Based on Dragonfly Ocellar Vision

DTIC Science & Technology

2006-07-27

9 10 Technical horizon sensors Over the past few years, a remarkable proliferation of designs for micro-aerial vehicles (MAVs) has occurred... photodiode Fig. 15 Fig. 14 Sky scans with a GaP UV pho to dio de a lo ng three vert ical paths. A ngle o f v iew 30 degrees, 50% clo ud co ver, sun at...Australia Email: gert.stange@anu.edu.au A biomimetic algorithm for flight stabilization in airborne vehicles , based on dragonfly ocellar vision

Biomimetic/Optical Sensors for Detecting Bacterial Species

NASA Technical Reports Server (NTRS)

Homer, Margie; Ksendzov, Alexander; Yen, Shiao-Pin; Ryan, Margaret; Lazazzera, Beth

2006-01-01

Biomimetic/optical sensors have been proposed as means of real-time detection of bacteria in liquid samples through real-time detection of compounds secreted by the bacteria. Bacterial species of interest would be identified through detection of signaling compounds unique to those species. The best-characterized examples of quorum-signaling compounds are acyl-homoserine lactones and peptides. Each compound, secreted by each bacterium of an affected species, serves as a signal to other bacteria of the same species to engage in a collective behavior when the population density of that species reaches a threshold level analogous to a quorum. A sensor according to the proposal would include a specially formulated biomimetic film, made of a molecularly imprinted polymer (MIP), that would respond optically to the signaling compound of interest. The MIP film would be integrated directly onto an opticalwaveguide- based ring resonator for optical readout. Optically, the sensor would resemble the one described in Chemical Sensors Based on Optical Ring Resonators (NPO-40601), NASA Tech Briefs, Vol. 29, No. 10 (October 2005), page 32. MIPs have been used before as molecular- recognition compounds, though not in the manner of the present proposal. Molecular imprinting is an approach to making molecularly selective cavities in a polymer matrix. These cavities function much as enzyme receptor sites: the chemical functionality and shape of a cavity in the polymer matrix cause the cavity to bind to specific molecules. An MIP matrix is made by polymerizing monomers in the presence of the compound of interest (template molecule). The polymer forms around the template. After the polymer solidifies, the template molecules are removed from the polymer matrix by decomplexing them from their binding sites and then dissolving them, leaving cavities that are matched to the template molecules in size, shape, and chemical functionality. The cavities thus become molecular-recognition sites

Is the mu-oxo-mu-peroxodiiron intermediate of a ribonucleotide reductase biomimetic a possible oxidant of epoxidation reactions?

PubMed

de Visser, Sam P

2008-01-01

Density functional calculations on a mu-oxo-mu-peroxodiiron complex (1) with a tetrapodal ligand BPP (BPP=N,N-bis(2-pyridylmethyl)-3-aminopropionate) are presented that is a biomimetic of the active site region of ribonucleotide reductase (RNR). We have studied all low-lying electronic states and show that it has close-lying broken-shell singlet and undecaplet (S=0, 5) ground states with essentially two sextet spin iron atoms. In strongly distorted electronic systems in which the two iron atoms have different spin states, the peroxo group moves considerably out of the plane of the mu-oxodiiron group due to orbital rearrangements. The calculated absorption spectra of (1,11)1 are in good agreement with experimental studies on biomimetics and RNR enzyme systems. Moreover, vibrational shifts in the spectrum due to (18)O(2) substitution of the oxygen atoms in the peroxo group follow similar trends as experimental observations. To identify whether the mu-oxo-mu-1,2-peroxodiiron or the mu-oxo-mu-1,1-peroxodiiron complexes are able to epoxidize substrates, we studied the reactivity patterns versus propene. Generally, the reactions are stepwise via radical intermediates and proceed by two-state reactivity patterns on competing singlet and undecaplet spin state surfaces. However, both the mu-oxo-mu-1,2-peroxodiiron and mu-oxo-mu-1,1-peroxodiiron complex are sluggish oxidants with high epoxidation barriers. The epoxidation barriers for the mu-oxo-mu-1,1-peroxodiiron complex are significantly lower than the ones for the mu-oxo-mu-1,2-peroxodiiron complex but still are too high to be considered for catalytic properties. Thus, theory has ruled out two possible peroxodiiron catalysts as oxidants in RNR enzymes and biomimetics and the quest to find the actual oxidant in the enzyme mechanism continues.

Software architecture of biomimetic underwater vehicle

NASA Astrophysics Data System (ADS)

Praczyk, Tomasz; Szymak, Piotr

2016-05-01

Autonomous underwater vehicles are vehicles that are entirely or partly independent of human decisions. In order to obtain operational independence, the vehicles have to be equipped with a specialized software. The main task of the software is to move the vehicle along a trajectory with collision avoidance. Moreover, the software has also to manage different devices installed on the vehicle board, e.g. to start and stop cameras, sonars etc. In addition to the software embedded on the vehicle board, the software responsible for managing the vehicle by the operator is also necessary. Its task is to define mission of the vehicle, to start, to stop the mission, to send emergency commands, to monitor vehicle parameters, and to control the vehicle in remotely operated mode. An important objective of the software is also to support development and tests of other software components. To this end, a simulation environment is necessary, i.e. simulation model of the vehicle and all its key devices, the model of the sea environment, and the software to visualize behavior of the vehicle. The paper presents architecture of the software designed for biomimetic autonomous underwater vehicle (BAUV) that is being constructed within the framework of the scientific project financed by Polish National Center of Research and Development.

Flight Control of Biomimetic Air Vehicles Using Vibrational Control and Averaging

NASA Astrophysics Data System (ADS)

Tahmasian, Sevak; Woolsey, Craig A.

2017-08-01

A combination of vibrational inputs and state feedback is applied to control the flight of a biomimetic air vehicle. First, a control strategy is developed for longitudinal flight, using a quasi-steady aerodynamic model and neglecting wing inertial effects. Vertical and forward motion is controlled by modulating the wings' stroke and feather angles, respectively. Stabilizing control parameter values are determined using the time-averaged dynamic model. Simulations of a system resembling a hawkmoth show that the proposed controller can overcome modeling error associated with the wing inertia and small parameter uncertainties when following a prescribed trajectory. After introducing the approach through an application to longitudinal flight, the control strategy is extended to address flight in three-dimensional space.

Synthesis and morphogenesis of organic and inorganic polymers by means of biominerals and biomimetic materials.

PubMed

Kijima, Misako; Oaki, Yuya; Munekawa, Yurika; Imai, Hiroaki

2013-02-11

We have studied the simultaneous synthesis and morphogenesis of polymer materials with hierarchical structures from nanoscopic to macroscopic scales. The morphologies of the original materials can be replicated to the polymer materials. In general, it is not easy to achieve the simultaneous synthesis and morphogenesis of polymer material even using host materials. In the present work, four biominerals and three biomimetic mesocrystal structures are used as the host materials or templates and polypyrrole, poly(3-hexylthiopehene), and silica were used as the precursors for the simultaneous syntheses and morphogenesis of polymer materials. The host materials with the hierarchical structure possess the nanospace for the incorporation of the monomers. After the incorporation of the monomers, the polymerization reaction proceeds in the nanospace with addition of the initiator agents. Then, the dissolution of the host materials leads to the formation and morphogenesis of the polymer materials. The scheme of the replication can be classified into the three types based on the structures of the host materials (types I-III). The type I template facilitates the hierarchical replication of the whole host material, type II mediates the hierarchical surface replication, and type III induces the formation of the two-dimensional nanosheets. Based on these results, the approach for the coupled synthesis and morphogenesis can be applied to a variety of combinations of the templates and polymer materials. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

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.

Structure, biomimetics, and fluid dynamics of fish skin surfaces*

NASA Astrophysics Data System (ADS)

Lauder, George V.; Wainwright, Dylan K.; Domel, August G.; Weaver, James C.; Wen, Li; Bertoldi, Katia

2016-10-01

The interface between the fluid environment and the surface of the body in swimming fishes is critical for both physiological and hydrodynamic functions. The skin surface in most species of fishes is covered with bony scales or toothlike denticles (in sharks). Despite the apparent importance of fish surfaces for understanding aquatic locomotion and near-surface boundary layer flows, relatively little attention has been paid to either the nature of surface textures in fishes or possible hydrodynamic effects of variation in roughness around the body surface within an individual and among species. Fish surfaces are remarkably diverse and in many bony fishes scales can have an intricate surface texture with projections, ridges, and comblike extensions. Shark denticles (or scales) are toothlike and project out of the skin to form a complexly textured surface that interacts with free-stream flow. Manufacturing biomimetic foils with fishlike surfaces allows hydrodynamic testing and we emphasize here the importance of dynamic test conditions where the effect of surface textures is assessed under conditions of self-propulsion. We show that simple two-dimensional foils with patterned cuts do not perform as well as a smooth control surface, but that biomimetic shark skin foils can swim at higher self-propelled speeds than smooth controls. When the arrangement of denticles on the foil surface is altered, we find that a staggered-overlapped pattern outperforms other arrangements. Flexible foils made of real shark skin outperform sanded controls when foils are moved with a biologically realistic motion program. We suggest that focus on the mechanisms of drag reduction by fish surfaces has been too limiting and an additional role of fish surface textures may be to alter leading edge vortices and flow patterns on moving surfaces in a way that enhances thrust. Analysis of water flow over an artificial shark skin foil under both static and dynamic conditions shows that a shear layer

Design and synthesis of a tetradentate '3-amine-1-carboxylate' ligand to mimic the metal binding environment at the non-heme iron(II) oxidase active site.

PubMed

Dungan, Victoria J; Ortin, Yannick; Mueller-Bunz, Helge; Rutledge, Peter J

2010-04-07

Non-heme iron(II) oxidases (NHIOs) catalyse a diverse array of oxidative chemistry in Nature. As part of ongoing efforts to realize biomimetic, iron-mediated C-H activation, we report the synthesis of a new 'three-amine-one-carboxylate' ligand designed to complex with iron(II) and mimic the NHIO active site. The tetradentate ligand has been prepared as a single enantiomer in nine synthetic steps from N-Cbz-L-alanine, pyridine-2,6-dimethanol and diphenylamine, using Seebach oxazolidinone chemistry to control the stereochemistry. X-Ray crystal structures are reported for two important intermediates, along with variable temperature NMR experiments to probe the hindered interconversion of conformational isomers of several key intermediates, 2,6-disubstituted pyridine derivatives. The target ligand and an N-Cbz-protected precursor were each then complexed with iron(II) and tested for their ability to promote alkene dihydroxylation, using hydrogen peroxide as the oxidant.

Biomimetic Antigenic Nanoparticles Elicit Controlled Protective Immune Response to Influenza

PubMed Central

Patterson, Dustin P.; Rynda-Apple, Agnieszka; Harmsen, Ann L.; Harmsen, Allen G.; Douglas, Trevor

2013-01-01

Here we present a biomimetic strategy towards nanoparticle design for controlled immune response through encapsulation of conserved internal influenza proteins on the interior of virus like particles (VLPs) to direct CD8+ cytotoxic T cell protection. Programmed encapsulation and sequestration of the conserved nucleoprotein (NP) from influenza on the interior of a VLP, derived from the bacteriophage P22, results in a vaccine that provides multi-strain protection against 100 times lethal doses of influenza in an NP specific CD8+ T cell-dependent manner. VLP assembly and encapsulation of the immunogenic NP cargo protein is the result of a genetically programmed self-assembly making this strategy amendable to the quick production of vaccines to rapidly emerging pathogens. Addition of adjuvants or targeting molecules were not required for eliciting the protective response. PMID:23540530

3D Bioprinting of Artificial Tissues: Construction of Biomimetic Microstructures.

PubMed

Luo, Yongxiang; Lin, Xin; Huang, Peng

2018-04-24

It is promising that artificial tissues/organs for clinical application can be produced via 3D bioprinting of living cells and biomaterials. The construction of microstructures biomimicking native tissues is crucially important to create artificial tissues with biological functions. For instance, the fabrication of vessel-like networks to supply cells with initial nutrient and oxygen, and the arrangement of multiple types of cells for creating lamellar/complex tissues through 3D bioprinting are widely reported. The current advances in 3D bioprinting of artificial tissues from the view of construction of biomimetic microstructures, especially the fabrication of lamellar, vascular, and complex structures are summarized. In the end, the conclusion and perspective of 3D bioprinting for clinical applications are elaborated. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomimetic Hydroxyapatite Growth on Functionalized Surfaces of Ti-6Al-4V and Ti-Zr-Nb Alloys

NASA Astrophysics Data System (ADS)

Pylypchuk, Ie V.; Petranovskaya, A. L.; Gorbyk, P. P.; Korduban, A. M.; Markovsky, P. E.; Ivasishin, O. M.

2015-08-01

A biomimetic approach for coating titanium-containing alloys with hydroxyapatite (HA) is reported in the article. Two types of Ti-containing alloys were chosen as an object for coating: Ti-6Al-4V (recommended for orthopedic application) and a novel highly biocompatible Ti-Zr-Nb alloy, with good mechanical compatibility due to a modulus that is more close to that of human bones (E ≈ 50 GPa instead of 110 GPa in Ti-6Al-4V). Coating process was carried out in a 10×-concentrated simulated body fluid (SBF)—synthetic analog of human body plasma. The effect of oxidized and carboxylated alloy surface on formation of biomimetic hydroxyapatite has been studied. By XRD, we found influence of thermal conditions on HA crystal formation and size. SEM images and Fourier transform infrared confirmed that hydroxyapatite with different morphology, crystallinity, and Ca/P ratio formed on metallic surfaces. X-ray photoelectron spectroscopy showed that in the Ti-6AL-4V sample the observed Ca/P ratio reach 0.97, whereas in the Ti-Zr-Nb sample the observed Ca/P ratio reach 1.15.

Creating Lithium-Ion Electrolytes with Biomimetic Ionic Channels in Metal-Organic Frameworks.

PubMed

Shen, Li; Wu, Hao Bin; Liu, Fang; Brosmer, Jonathan L; Shen, Gurong; Wang, Xiaofeng; Zink, Jeffrey I; Xiao, Qiangfeng; Cai, Mei; Wang, Ge; Lu, Yunfeng; Dunn, Bruce

2018-06-01

Solid-state electrolytes are the key to the development of lithium-based batteries with dramatically improved energy density and safety. Inspired by ionic channels in biological systems, a novel class of pseudo solid-state electrolytes with biomimetic ionic channels is reported herein. This is achieved by complexing the anions of an electrolyte to the open metal sites of metal-organic frameworks (MOFs), which transforms the MOF scaffolds into ionic-channel analogs with lithium-ion conduction and low activation energy. This work suggests the emergence of a new class of pseudo solid-state lithium-ion conducting electrolytes. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomimetic catalytic system driven by electron transfer for selective oxygenation of hydrocarbon.

PubMed

Yang, Guanyu; Ma, Yinfa; Xu, Jie

2004-09-01

Hydrocarbon oxyfunctionalization is a crucial industrial process. Most metallic catalysts require higher temperatures and often show lower selectivities. One of the intellectual approaches is the mimicry for bio-oxidation. We have established a biomimetic system with a nonmetallic redox center, composed of anthraquinones, N-hydroxyphthalimide, and zeolite HY, for selective hydrocarbon oxygenation by molecular oxygen. Selectivity of 95.8% for acetophenone and 66.2% conversion were accomplished for oxygenation of ethylbenzene at temperatures as low as 80 degrees C. The redox cycle, driven by one-electron transfer and product orientation by Zeolite HY, opens up the possibility of mimicking bio-oxidation under mild conditions.

Biomimetic wall-shaped hierarchical microstructure for gecko-like attachment.

PubMed

Kasem, Haytam; Tsipenyuk, Alexey; Varenberg, Michael

2015-04-21

Most biological hairy adhesive systems involved in locomotion rely on spatula-shaped terminal elements, whose operation has been actively studied during the last decade. However, though functional principles underlying their amazing performance are now well understood, due to technical difficulties in manufacturing the complex structure of hierarchical spatulate systems, a biomimetic surface structure featuring true shear-induced dynamic attachment still remains elusive. To try bridging this gap, a novel method of manufacturing gecko-like attachment surfaces is devised based on a laser-micromachining technology. This method overcomes the inherent disadvantages of photolithography techniques and opens wide perspectives for future production of gecko-like attachment systems. Advanced smart-performance surfaces featuring thin-film-based hierarchical shear-activated elements are fabricated and found capable of generating friction force of several tens of times the contact load, which makes a significant step forward towards a true gecko-like adhesive.

Efficient Enzyme-Free Biomimetic Sensors for Natural Phenol Detection.

PubMed

Ferreira Garcia, Luane; Ribeiro Souza, Aparecido; Sanz Lobón, Germán; Dos Santos, Wallans Torres Pio; Alecrim, Morgana Fernandes; Fontes Santiago, Mariângela; de Sotomayor, Rafael Luque Álvarez; de Souza Gil, Eric

2016-08-13

The development of sensors and biosensors based on copper enzymes and/or copper oxides for phenol sensing is disclosed in this work. The electrochemical properties were studied by cyclic and differential pulse voltammetry using standard solutions of potassium ferrocyanide, phosphate/acetate buffers and representative natural phenols in a wide pH range (3.0 to 9.0). Among the natural phenols herein investigated, the highest sensitivity was observed for rutin, a powerful antioxidant widespread in functional foods and ubiquitous in the plant kingdom. The calibration curve for rutin performed at optimum pH (7.0) was linear in a broad concentration range, 1 to 120 µM (r = 0.99), showing detection limits of 0.4 µM. The optimized biomimetic sensor was also applied in total phenol determination in natural samples, exhibiting higher stability and sensitivity as well as distinct selectivity for antioxidant compounds.

A biomimetic accelerometer inspired by the cricket's clavate hair

PubMed Central

Droogendijk, H.; de Boer, M. J.; Sanders, R. G. P.; Krijnen, G. J. M.

2014-01-01

Crickets use so-called clavate hairs to sense (gravitational) acceleration to obtain information on their orientation. Inspired by this clavate hair system, a one-axis biomimetic accelerometer has been developed and fabricated using surface micromachining and SU-8 lithography. An analytical model is presented for the design of the accelerometer, and guidelines are derived to reduce responsivity due to flow-induced contributions to the accelerometer's output. Measurements show that this microelectromechanical systems (MEMS) hair-based accelerometer has a resonance frequency of 320 Hz, a detection threshold of 0.10 ms−2 and a dynamic range of more than 35 dB. The accelerometer exhibits a clear directional response to external accelerations and a low responsivity to airflow. Further, the accelerometer's physical limits with respect to noise levels are addressed and the possibility for short-term adaptation of the sensor to the environment is discussed. PMID:24920115

Exquisite Enzyme-Fenton Biomimetic Catalysts for Hydroxyl Radical Production by Mimicking an Enzyme Cascade.

PubMed

Zhang, Qi; Chen, Shuo; Wang, Hua; Yu, Hongtao

2018-03-14

Hydrogen peroxide (H 2 O 2 ) is a key reactant in the Fenton process. As a byproduct of enzymatic reaction, H 2 O 2 can be obtained via catalytical oxidation of glucose using glucose oxidase in the presence of O 2 . Another oxidation product (gluconic acid) can suitably adjust the microenvironmental pH contributing to the Fe 3+ /Fe 2+ cycle in the Fenton reaction. Enzymes are extremely efficient at catalyzing a variety of reactions with high catalytic activity, substrate specificity, and yields in living organisms. Inspired by the multiple functions of natural multienzyme systems, an exquisite nanozyme-modified α-FeOOH/porous carbon (PC) biomimetic catalyst constructed by in situ growth of glucose oxidase-mimicking Au nanoparticles and crystallization of adsorbed ferric ions within carboxyl into hierarchically PC is developed as an efficient enzyme-Fenton catalyst. The products (H 2 O 2 , ∼4.07 mmol·L -1 ) of the first enzymatic reaction are immediately used as substrates for the second Fenton-like reaction to generate the valuable • OH (∼96.84 μmol·L -1 ), thus mimicking an enzyme cascade pathway. α-FeOOH nanocrystals, attached by C-O-Fe bondings, are encapsulated into the mesoporous PC frameworks, facilitating the electron transfer between α-FeOOH and the PC support and greatly suppressing iron leaching. This study paves a new avenue for designing biomimetic enzyme-based Fenton catalysts mimicking a natural system for • OH production.

A biomimetic bioelectronic tongue: A switch for On- and Off- response of acid sensations.

PubMed

Zhang, Wei; Chen, Peihua; Zhou, Lianqun; Qin, Zhen; Gao, Keqiang; Yao, Jia; Li, Chuanyu; Wang, Ping

2017-06-15

The perception of sour taste in mammals is important for its basic modality properties and avoiding toxic substances. We explore a biomimetic bioelectronic tongue, which integrate MEA (microelectrode array) and taste receptor cell for acid detection as a switch. However, the acid-sensing mechanism and coding of the taste receptor cells in the periphery is not well understood, with long-standing debate. Therefore, we firstly construct a Hodgkin-Huxley type mathematical model of whole-cell acid-sensing taste receptor cells based on the electrophysiologic patch clamp recordings with different acid sensitive receptor expressing and different acidic stimulations. ASICs and PKDL channels are two most promising candidates for acidic sensation. ASICs channels contribute to the On response, and PKDL channels coding the Offset stimulations respectively, which function as a pair for switch. Therefore, with the advantage of effective and noninvasive detection for MEA, a sour taste biosensor based on MEA and taste receptor cells was designed and established to detect sour response from the elementary acid sensitive taste receptor cells during and after stimulus. From simulation and extracelluar potential recordings, we found the biomimetic bioelectronic tongue was acid-sensitive, as acid stimulation pH decrease, the firing frequency significantly increase. Furthermore, this reliable and effective MEA based bioelectronic tongue functioned as a switch for stimulation On and Off. This study provided a powerful platform to recognize sour stimulation and help elucidate the sour taste sensation and coding mechanism. Copyright © 2016 Elsevier B.V. All rights reserved.

Mechanical design, fabrication, and test of biomimetic fish robot using LIPCA as artificial muscle

NASA Astrophysics Data System (ADS)

Wiguna, T.; Syaifuddin, M.; Park, Hoon C.; Heo, S.

2006-03-01

This paper presents a mechanical design, fabrication and test of biomimetic fish robot using the Lightweight Piezocomposite Curved Actuator (LIPCA). We have designed a mechanism for converting actuation of the LIPCA into caudal fin movement. This linkage mechanism consists of rack-pinion system and four-bar linkage. We also have tested four types of caudal fin in order to examine effect of different shape of caudal fin on thrust generation by tail beat. Subsequently, based on the caudal fin test, four caudal fins which resemble fish caudal fin shapes of ostraciiform, subcarangiform, carangiform and thunniform, respectively, are attached to the posterior part of the robotic fish. The swimming test using 300 V pp input with 1 Hz to 1.5 Hz frequency was conducted to investigate effect of changing tail beat frequency and shape of caudal fin on the swimming speed of the robotic fish. The maximum swimming speed was reached when the device was operated at its natural swimming frequency. At the natural swimming frequency 1 Hz, maximum swimming speeds of 1.632 cm/s, 1.776 cm/s, 1.612 cm/s and 1.51 cm/s were reached for ostraciiform-, subcarangiform-, carangiform- and thunniform-like caudal fins, respectively. Strouhal numbers, which are a measure of thrust efficiency, were calculated in order to examine thrust performance of the present biomimetic fish robot. We also approximated the net forward force of the robotic fish using momentum conservation principle.

Engineering a biomimetic three-dimensional nanostructured bone model for breast cancer bone metastasis study.

PubMed

Zhu, Wei; Wang, Mian; Fu, Yebo; Castro, Nathan J; Fu, Sidney W; Zhang, Lijie Grace

2015-03-01

Traditional breast cancer (BrCa) bone metastasis models contain many limitations with regards to controllability, reproducibility and flexibility of design. In this study, a novel biomimetic bone microenvironment was created by integrating hydroxyapatite (HA) and native bioactive factors deposited by osteogenic induction of human bone marrow mesenchymal stem cells (MSCs) within a cytocompatible chitosan hydrogel. It was found that a 10% nanocrystalline HA (nHA) chitosan scaffold exhibited the highest BrCa adhesion and proliferation when compared to chitosan scaffolds with 20% nHA, 10% and 20% microcrystalline HA as well as amorphous HA. This 3-D tunable bone scaffold can provide a biologically relevant environment, increase cell-cell and cell-matrix interactions as found in native bone, and retain the behavior of BrCa cells with different metastasis potential (i.e. highly metastatic MDA-MB-231, less metastatic MCF-7 and transfected MDA-MB-231). The co-culture of MSCs and MDA-MB-231 in this bone model illustrated that MSCs have the capacity to upregulate the expression of the well-known metastasis-associated gene metadherin within BrCa cells. In summary, this study illustrates the ability of our 3-D bone model to create a biomimetic environment conducive to recapitulating the behavior of metastatic BrCa cells, making it a promising tool for in vitro BrCa cell bone metastasis study and for the discovery of potential therapeutics. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Bactericidal activity of biomimetic diamond nanocone surfaces.

PubMed

Fisher, Leanne E; Yang, Yang; Yuen, Muk-Fung; Zhang, Wenjun; Nobbs, Angela H; Su, Bo

2016-03-17

The formation of biofilms on implant surfaces and the subsequent development of medical device-associated infections are difficult to resolve and can cause considerable morbidity to the patient. Over the past decade, there has been growing recognition that physical cues, such as surface topography, can regulate biological responses and possess bactericidal activity. In this study, diamond nanocone-patterned surfaces, representing biomimetic analogs of the naturally bactericidal cicada fly wing, were fabricated using microwave plasma chemical vapor deposition, followed by bias-assisted reactive ion etching. Two structurally distinct nanocone surfaces were produced, characterized, and the bactericidal ability examined. The sharp diamond nanocone features were found to have bactericidal capabilities with the surface possessing the more varying cone dimension, nonuniform array, and decreased density, showing enhanced bactericidal ability over the more uniform, highly dense nanocone surface. Future research will focus on using the fabrication process to tailor surface nanotopographies on clinically relevant materials that promote both effective killing of a broader range of microorganisms and the desired mammalian cell response. This study serves to introduce a technology that may launch a new and innovative direction in the design of biomaterials with capacity to reduce the risk of medical device-associated infections.

Scaling laws for a compliant biomimetic swimmer

NASA Astrophysics Data System (ADS)

Gibouin, Florence; Raufaste, Christophe; Bouret, Yann; Argentina, Mederic

2017-11-01

Motivated by the seminal work of Lord Lighthill in the sixties, we study the motion of inertial aquatic swimmers that propels with undulatory gaits. In 2014, Gazzola et al. have uncovered the law linking the swimming velocity to the kinematics of the swimmer and the fluid properties. At high Reynolds numbers, the velocity appears to be equal to 0.4 Af /(2 π) , where A and f are respectively the amplitude and the frequency of the oscillating fin. We have constructed a compliant biomimetic swimmer, whose muscles have been modeled through a torque distribution thanks to a servomotor. A soft polymeric material mimics the flesh and provides the flexibility. By immersing our robot into a water tunnel, we find and characterize the operating point for which the propulsive force balances the drag. We bring the first experimental proof of the former law and probe large amplitude undulations which exhibits nonlinear effects. All data collapse perfectly onto a single master curve. We investigate the role of the fin flexibility by varying its length and its thickness and we figured out the existence of an efficient swimming regime. We thank the support of CNRS and Université Côte d'Azur.

Synthesis of magnetite nanoparticles for bio- and nanotechnology: genetic engineering and biomimetics of bacterial magnetosomes.

PubMed

Lang, Claus; Schüler, Dirk; Faivre, Damien

2007-02-12

Magnetotactic bacteria (MTB) have the ability to navigate along the Earth's magnetic field. This so-called magnetotaxis is a result of the presence of magnetosomes, organelles which comprise nanometer-sized intracellular crystals of magnetite (Fe(3)O(4)) enveloped by a membrane. Because of their unique characteristics, magnetosomes have a high potential for nano- and biotechnological applications, which require a specifically designed particle surface. The functionalization of magnetosomes is possible either by chemical modification of purified particles or by genetic engineering of magnetosome membrane proteins. The second approach is potentially superior to chemical approaches as a large variety of biological functions such as protein tags, fluorophores, and enzymes may be directly incorporated in a site-specific manner during magnetosome biomineralization. An alternative to the bacterial production of magnetosomes are biomimetic approaches, which aim to mimic the bacterial biomineralization pathway in vitro. In MTB a number of magnetosome proteins with putative functions in the biomineralization of the nanoparticles have been identified by genetic and biochemical approaches. The initial results obtained by several groups indicate that some of these proteins have an impact on nanomagnetite properties in vitro. In this article the key features of magnetosomes are discussed, an overview of their potential applications are given, and different strategies are proposed for the functionalization of magnetosome particles and for the biomimetism of their biomineralization pathway.

Comparison of physical characteristics and cell culture test of hydroxyapatite/collagen composite coating on NiTi SMA: electrochemical deposition and chemically biomimetic growth

NASA Astrophysics Data System (ADS)

Hu, Kai; Yang, Xianjin; Cai, Yanli; Cui, Zhenduo; Wei, Qiang

2007-07-01

A hydroxyapatite (HA)/collagen (COL) composite coating on NiTi shape memory alloy (SMA) was prepared by eletrochemical deposition (ELD) in modified simulated body fluid (MSBF). To draw comparisons of physical characteristics and bioactivity of the composite coating, the HA/COL composite coating was also prepared by chemically biomimetic growth (BG) and the ELD coating was re-soaked in MSBF again for further biomimetic growth (called EBG method in this paper). It was indicated that the c-axis of HA crystals was oriented parallel to the longitudinal direction of the COL fibril in BG and EBG coating, which could not found in ELD coating. The EBG method could induce a denser, thicker and better crystallized HA/COL coating. The cell culture test indicated that the BG coating presented better cell biocompatibility.

Rapid syntheses of dehydrodiferulates via biomimetic radical coupling reactions of ethyl ferulate.

PubMed

Lu, Fachuang; Wei, Liping; Azarpira, Ali; Ralph, John

2012-08-29

Dehydrodimerization of ferulates in grass cell walls provides a pathway toward cross-linking polysaccharide chains limiting the digestibility of carbohydrates by ruminant bacteria and in general affecting the utilization of grass as a renewable bioresource. Analysis of dehydrodiferulates (henceforth termed diferulates) in plant cell walls is useful in the evaluation of the quality of dairy forages as animal feeds. Therefore, there has been considerable demand for quantities of diferulates as standards for such analyses. Described here are syntheses of diferulates from ethyl ferulate via biomimetic radical coupling reactions using the copper(II)-tetramethylethylenediamine [CuCl(OH)-TMEDA] complex as oxidant or catalyst. Although CuCl(OH)-TMEDA oxidation of ethyl ferulate in acetonitrile produced mixtures composed of 8-O-4-, 8-5-, 8-8- (cyclic and noncyclic), and 5-5-coupled diferulates, a catalyzed oxidation using CuCl(OH)-TMEDA as catalyst and oxygen as an oxidant resulted in better overall yields of such diferulates. Flash chromatographic fractionation allowed isolation of 8-8- and 5-5-coupled diferulates. 8-5-Diferulate coeluted with 8-O-4-diferulate but was separated from it via crystallization; the 8-O-4 diferulate left in the mother solution was isolated by rechromatography following a simple tetrabutylammonium fluoride treatment that converted 8-5-diferulate to another useful diferulate, 8-5-(noncyclic) diferulate. Therefore, six of the nine (5-5, 8-O-4, 8-5-c, 8-5-nc, 8-5-dc, 8-8-c, 8-8-nc, 8-8-THF, 4-O-5) diferulic acids that have to date been found in the alkaline hydrolysates of plant cell walls can be readily synthesized by the CuCl(OH)-TMEDA catalyzed aerobic oxidative coupling reaction and subsequent saponification described here.

Calcium powered phloem protein of SEO gene family “Forisome” functions in wound sealing and act as biomimetic smart materials

PubMed Central

Srivastava, Vineet Kumar; Tuteja, Narendra

2014-01-01

Forisomes protein belongs to SEO gene family and is unique to Fabaceae family. These proteins are located in sieve tubes of phloem and function to prevent loss of nutrient-rich photoassimilates, upon mechanical injury/wounding. Forisome protein is also known as ATP independent, mechanically active proteins. Despite the wealth of information role of forisome in plants are not yet fully understood. Recent reports suggest that forisomes protein can act as ideal model to study self assembly mechanism for development of nanotechnological devices like microfluidic system application in space exploration mission. Improvement in micro instrument is highly demanding and has been a key technology by NASA in future space exploration missions. Based on its physical parameters, forisome are found to be ideal biomimetic materials for micro fluidic system because the conformational shifts can be replicated in vitro and are fully reversible over large number of cycles. By the use of protein engineering forisome recombinant protein can be tailored. Due to its unique ability to convert chemical energy into mechanical energy forisome has received much attention. For nanotechnological application and handling biomolecules such as DNA, RNA, protein and cell as a whole microfluidic system will be the most powerful technology. The discovery of new biomimetic smart materials has been a key factor in development of space science and its requirements in such a challenging environment. The field of microfludic, particularly in terms of development of its components along with identification of new biomimetic smart materials, deserves more attention. More biophysical investigation is required to characterize it to make it more suitable under parameters of performance. PMID:25763691

New biomimetic approach to determine the bioavailability of triclosan in soils and its validation with the wheat plant uptake bioassay.

PubMed

Jachero, Lourdes; Ahumada, Inés; Fuentes, Edwar; Richter, Pablo

2015-01-01

A new biomimetic approach for triclosan (TCS) was developed based on the leaching of the analyte from different biosolid-amended agricultural soils and the subsequent extraction of the leachates, using a rotating disk sorptive extraction (RDSE) procedure. The leaching equilibrium for TCS was reached at 3h when the ISO method (ISO/TS 21268-1:2007) was followed. The concentrations determined by this biomimetic method were compared with the bioavailability of TCS, determined by its accumulation in the roots of wheat plants grown in the same soil-biosolid systems. It was observed that the amount of organic matter in the soil matrix was a determining factor for mobilization of TCS. An increasing biosolid rate applied to soils resulted in a reduced mobility of TCS because the high amount of organic matter provided by the biosolid increased the hydrophobic interaction between TCS and the matrix. Similarly, increasing biosolid concentrations in the soil significantly decreased the bioavailability of TCS to the wheat plant. Thus, the bioavailability factor in wheat roots decreased from 0.22 to 0.08 for a soil having a pH of 8.2, when the biosolid rate was increased from 30 to 200 Mg ha(-1), respectively. A significant correlation (R=0.98) was obtained between TCS concentration in wheat plants and the proposed biomimetic methodology, indicating that the latter can predict the bioavailability in a time period as short as 180 min. The results of this study confirm our previous findings that amending soils with biosolids is beneficial for immobilizing low polarity contaminants and helps prevent their percolation through the soil profile and into groundwater. Copyright © 2014 Elsevier Ltd. All rights reserved.

The use of sodium trimetaphosphate as a biomimetic analog of matrix phosphoproteins for remineralization of artificial caries-like dentin

PubMed Central

Liu, Yan; Li, Nan; Qi, Yipin; Niu, Li-na; Elshafiy, Sally; Mao, Jing; Breschi, Lorenzo; Pashley, David H.; Tay, Franklin R.

2011-01-01

Objectives This study examined the use of sodium trimetaphosphate (STMP) as a biomimetic analog of matrix phosphoproteins for remineralization of artificial carious-affected dentin. Methods Artificial carious lesions with lesion depths of 300±30 µm were created by pH-cycling. 2.5% hydrolyzed STMP was applied to the artificial carious lesions to phosphorylate the partially-demineralized collagen matrix. Half of the STMP-treated specimens were bonded with One-Step. The adhesive and non-adhesive infiltrated specimens were remineralized in a Portland cement-simulated body fluid system containing polyacrylic acid (PAA) to stabilize amorphous calcium phosphate as nanoprecursors. Micro-computed tomography (micro-CT) and transmission electron microscopy (TEM) were used to evaluate the results of remineralization after a 4-month period. Results In absence of PAA and STMP as biomimetic analogs (control groups), there was no remineralization irrespective of whether the lesions were infiltrated with adhesive. For the STMP-treated experimental groups immersed in PAA-containing simulated body fluid, specimens without adhesive infiltration were more heavily remineralized than those infiltrated with adhesive. Statistical analysis of the 4-month micro-CT data revealed significant differences in the lesion depth, relative mineral content along the lesion surface and changes in ΔZ between the non-adhesive and adhesive experimental groups (p<0.05 for all the three parameters). TEM examination indicated that collagen degradation occurred in both the non-adhesive and adhesive control and experimental groups after 4 months of remineralization. Significance Biomimetic remineralization using STMP is a promising method to remineralize artificial carious lesions particularly in areas devoid of seed crystallites. Future studies should consider the incorporation of MMP-inhibitors within the partially-demineralized collagen matrix to prevent collagen degradation during remineralization. PMID

Hydrodynamically Lubricated and Grooved Biomimetic Self-Adapting Surfaces

PubMed Central

Jackson, Robert L.; Lei, Jiang

2014-01-01

In many machines and mechanical components, there is a need for new bearing technologies to reduce friction and wear, and provide precision control of motion when the load is varied. This can be provided by electronically controlled actuators and sensors on the surfaces, but then the system reliability can be an issue. In contrast, biomimetic surfaces can be created that adapt mechanically to variations in load. This work uses numerical methods to research the use of self-adapting surfaces for bearings that are based on the deformable nature of biological materials such as articular cartilage. These surfaces are designed to change their profiles to achieve a desired behavior, without any external control. The surfaces change their profile to control the film height and tilt of the bearing to a near constant value for different loads. If the surfaces are tilted, the grooved self-adapting surfaces will also react with a larger restoring moment than a conventional grooved surface. These surfaces could be beneficial to applications where electrical systems and controls are not feasible. PMID:24956441

Optimization of a tensegrity wing for biomimetic applications

NASA Astrophysics Data System (ADS)

Moored, Keith W., III; Taylor, Stuart A.; Bart-Smith, Hilary

2006-03-01

Current attempts to build fast, efficient, and maneuverable underwater vehicles have looked to nature for inspiration. However, they have all been based on traditional propulsive techniques, i.e. rotary motors. In the current study a promising and potentially revolutionary approach is taken that overcomes the limitations of these traditional methods-morphing structure concepts with integrated actuation and sensing. Inspiration for this work comes from the manta ray (Manta birostris) and other batoid fish. These creatures are highly maneuverable but are also able to cruise at high speeds over long distances. In this paper, the structural foundation for the biomimetic morphing wing is a tensegrity structure. A preliminary procedure is presented for developing morphing tensegrity structures that include actuating elements. A shape optimization method is used that determines actuator placement and actuation amount necessary to achieve the measured biological displacement field of a ray. Lastly, an experimental manta ray wing is presented that measures the static and dynamic pressure field acting on the ray's wings during a normal flapping cycle.

Hydrodynamically lubricated and grooved biomimetic self-adapting surfaces.

PubMed

Jackson, Robert L; Lei, Jiang

2014-06-04

In many machines and mechanical components, there is a need for new bearing technologies to reduce friction and wear, and provide precision control of motion when the load is varied. This can be provided by electronically controlled actuators and sensors on the surfaces, but then the system reliability can be an issue. In contrast, biomimetic surfaces can be created that adapt mechanically to variations in load. This work uses numerical methods to research the use of self-adapting surfaces for bearings that are based on the deformable nature of biological materials such as articular cartilage. These surfaces are designed to change their profiles to achieve a desired behavior, without any external control. The surfaces change their profile to control the film height and tilt of the bearing to a near constant value for different loads. If the surfaces are tilted, the grooved self-adapting surfaces will also react with a larger restoring moment than a conventional grooved surface. These surfaces could be beneficial to applications where electrical systems and controls are not feasible.

Biomimetic Hybrid Feedback Feedforward Neural-Network Learning Control.

PubMed

Pan, Yongping; Yu, Haoyong

2017-06-01

This brief presents a biomimetic hybrid feedback feedforward neural-network learning control (NNLC) strategy inspired by the human motor learning control mechanism for a class of uncertain nonlinear systems. The control structure includes a proportional-derivative controller acting as a feedback servo machine and a radial-basis-function (RBF) NN acting as a feedforward predictive machine. Under the sufficient constraints on control parameters, the closed-loop system achieves semiglobal practical exponential stability, such that an accurate NN approximation is guaranteed in a local region along recurrent reference trajectories. Compared with the existing NNLC methods, the novelties of the proposed method include: 1) the implementation of an adaptive NN control to guarantee plant states being recurrent is not needed, since recurrent reference signals rather than plant states are utilized as NN inputs, which greatly simplifies the analysis and synthesis of the NNLC and 2) the domain of NN approximation can be determined a priori by the given reference signals, which leads to an easy construction of the RBF-NNs. Simulation results have verified the effectiveness of this approach.

Inspection and analysis of the walls of fluid filled tubes by active electrolocation: a biomimetic approach

NASA Astrophysics Data System (ADS)

Gottwald, Martin; Mayekar, Kavita; Reiswich, Vladislav; Bousack, Herbert; Damalla, Deepak; Biswas, Shubham; Metzen, Michael G.; von der Emde, Gerhard

2011-04-01

During their nocturnal activity period, weakly electric fish employ a process called "active electrolocation" for navigation and object detection. They discharge an electric organ in their tail, which emits electrical current pulses, called electric organ discharges (EOD). Local EODs are sensed by arrays of electroreceptors in the fish's skin, which respond to modulations of the signal caused by nearby objects. Fish thus gain information about the size, shape, complex impedance and distance of objects. Inspired by these remarkable capabilities, we have designed technical sensor systems which employ active electrolocation to detect and analyse the walls of small, fluid filled pipes. Our sensor systems emit pulsed electrical signals into the conducting medium and simultaneously sense local current densities with an array of electrodes. Sensors can be designed which (i) analyse the tube wall, (ii) detect and localize material faults, (iii) identify wall inclusions or objects blocking the tube (iv) and find leakages. Here, we present first experiments and FEM simulations on the optimal sensor arrangement for different types of sensor systems and different types of tubes. In addition, different methods for sensor read-out and signal processing are compared. Our biomimetic sensor systems promise to be relatively insensitive to environmental disturbances such as heat, pressure, turbidity or muddiness. They could be used in a wide range of tubes and pipes including water pipes, hydraulic systems, and biological systems. Medical applications include catheter based sensors which inspect blood vessels, urethras and similar ducts in the human body.

Biomimetic soluble collagen purified from bones.

PubMed

Ferreira, Ana Marina; Gentile, Piergiorgio; Sartori, Susanna; Pagliano, Cristina; Cabrele, Chiara; Chiono, Valeria; Ciardelli, Gianluca

2012-11-01

Type I collagen has been extensively exploited as a biomaterial for biomedical applications and drug delivery; however, small molecular alterations occurring during the isolation procedure and its interaction with residual bone extracellular matrix molecules or proteins might affect the overall material biocompatibility and performance. The aim of the current work is to study the potential alterations in collagen properties and organization associated with the absence of proteoglycans, which mimic pathological conditions associated with age-related diseases. A new approach for evaluating the effect of proteoglycans on the properties of isolated type I collagen from the bone matrix is described. Additional treatment with guanidine hydrochloride was introduced to remove residual proteoglycans from the collagen matrix. The properties of the isolated collagen with/without guanidine hydrochloride treatment were investigated and compared with a commercial rabbit collagen as control. We demonstrate that the absence of proteoglycans in the isolated type I collagen affects its thermal properties, the extraction into its native structure, and its ability to hydrate and self-assemble into fibers. The fine control and tuning of all these features, linked to the absence of non-collagenous proteins as proteoglycans, offer the possibility of designing new strategies and biomaterials with advanced biomimetic properties aimed at regenerating bone tissue in the case of fragility and/or defects. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Bions: A Family of Biomimetic Mineralo-Organic Complexes Derived from Biological Fluids

PubMed Central

Martel, Jan; Young, John D.

2013-01-01

Mineralo-organic nanoparticles form spontaneously in human body fluids when the concentrations of calcium and phosphate ions exceed saturation. We have shown previously that these mineralo-organic nanoparticles possess biomimetic properties and can reproduce the whole phenomenology of the so-called nanobacteria—mineralized entities initially described as the smallest microorganisms on earth. Here, we examine the possibility that various charged elements and ions may form mineral nanoparticles with similar properties in biological fluids. Remarkably, all the elements tested, including sodium, magnesium, aluminum, calcium, manganese, iron, cobalt, nickel, copper, zinc, strontium, and barium form mineralo-organic particles with bacteria-like morphologies and other complex shapes following precipitation with phosphate in body fluids. Upon formation, these mineralo-organic particles, which we term bions, invariably accumulate carbonate apatite during incubation in biological fluids; yet, the particles also incorporate additional elements and thus reflect the ionic milieu in which they form. Bions initially harbor an amorphous mineral phase that gradually converts to crystals in culture. Our results show that serum produces a dual inhibition-seeding effect on bion formation. Using a comprehensive proteomic analysis, we identify a wide range of proteins that bind to these mineral particles during incubation in medium containing serum. The two main binding proteins identified, albumin and fetuin-A, act as both inhibitors and seeders of bions in culture. Notably, bions possess several biomimetic properties, including the possibility to increase in size and number and to be sub-cultured in fresh culture medium. Based on these results, we propose that bions represent biological, mineralo-organic particles that may form in the body under both physiological and pathological homeostasis conditions. These mineralo-organic particles may be part of a physiological cycle that

Flagellin based biomimetic coatings: From cell-repellent surfaces to highly adhesive coatings.

PubMed

Kovacs, Boglarka; Patko, Daniel; Szekacs, Inna; Orgovan, Norbert; Kurunczi, Sandor; Sulyok, Attila; Khanh, Nguyen Quoc; Toth, Balazs; Vonderviszt, Ferenc; Horvath, Robert

2016-09-15

Biomimetic coatings with cell-adhesion-regulating functionalities are intensively researched today. For example, cell-based biosensing for drug development, biomedical implants, and tissue engineering require that the surface adhesion of living cells is well controlled. Recently, we have shown that the bacterial flagellar protein, flagellin, adsorbs through its terminal segments to hydrophobic surfaces, forming an oriented monolayer and exposing its variable D3 domain to the solution. Here, we hypothesized that this nanostructured layer is highly cell-repellent since it mimics the surface of the flagellar filaments. Moreover, we proposed flagellin as a carrier molecule to display the cell-adhesive RGD (Arg-Gly-Asp) peptide sequence and induce cell adhesion on the coated surface. The D3 domain of flagellin was replaced with one or more RGD motifs linked by various oligopeptides modulating flexibility and accessibility of the inserted segment. The obtained flagellin variants were applied to create surface coatings inducing cell adhesion and spreading to different levels, while wild-type flagellin was shown to form a surface layer with strong anti-adhesive properties. As reference surfaces synthetic polymers were applied which have anti-adhesive (PLL-g-PEG poly(l-lysine)-graft-poly(ethylene glycol)) or adhesion inducing properties (RGD-functionalized PLL-g-PEG). Quantitative adhesion data was obtained by employing optical biochips and microscopy. Cell-adhesion-regulating coatings can be simply formed on hydrophobic surfaces by using the developed flagellin-based constructs. The developed novel RGD-displaying flagellin variants can be easily obtained by bacterial production and can serve as alternatives to create cell-adhesion-regulating biomimetic coatings. In the present work, we show for the first time that. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Construction of uric acid biosensor based on biomimetic titanate nanotubes.

PubMed

Tao, Haisheng; Wang, Xuebin; Wang, Xizhang; Hu, Yemin; Ma, Yanwen; Lu, Yinong; Hu, Zheng

2010-02-01

A uric acid biosensor has been fabricated through the immobilization of uricase on glassy carbon electrode modified by biomimetic titanate nanotubes of high specific surface area synthesized by hydrothermal decomposition. The so-constructed biosensor presents a high affinity to uric acid with a small apparent Michaelis-Menten constant of only 0.66 mM. The biosensor exhibits fairly good electrochemical properties such as the high sensitivity of 184.3 microAcm(-2)mM(-1), the fast response of less than 2 s, as well as the wide linear range from 1 microM to 5 mM. These performances indicate that titanate nanotubes could provide a favorable microenvironment for uricase immobilization, stabilize its biological activity, and function as an efficient electron conducting tunnel to facilitate the electron transfer. This suggests an important potential of titanate nanotubes in uric acid biosensors.

Time-Dependent Liquid Transport on a Biomimetic Topological Surface.

PubMed

Yu, Cunlong; Li, Chuxin; Gao, Can; Dong, Zhichao; Wu, Lei; Jiang, Lei

2018-05-02

Liquid drops impacting on a solid surface is a familiar phenomenon. On rainy days, it is quite important for leaves to drain off impacting raindrops. Water can bounce off or flow down a water-repellent leaf easily, but with difficulty on a hydrophilic leaf. Here, we show an interesting phenomenon in which impacting drops on the hydrophilic pitcher rim of Nepenthes alata can spread outward to prohibit water filling the pitcher tank. We mimic the peristome surface through a designed 3D printing and replicating way and report a time-dependently switchable liquid transport based on biomimetic topological structures, where surface curvature can work synergistically with the surface microtextures to manipulate the switchable spreading performance. Motived by this strange behavior, we construct a large-scaled peristome-mimetic surface in a 3D profile, demonstrating the ability to reduce the need to mop or to squeegee drops that form during the drop impacting process on pipes or other curved surfaces in food processing, moisture transfer, heat management, etc.

Plant Surfaces: Structures and Functions for Biomimetic Innovations

NASA Astrophysics Data System (ADS)

Barthlott, Wilhelm; Mail, Matthias; Bhushan, Bharat; Koch, Kerstin

2017-04-01

An overview of plant surface structures and their evolution is presented. It combines surface chemistry and architecture with their functions and refers to possible biomimetic applications. Within some 3.5 billion years biological species evolved highly complex multifunctional surfaces for interacting with their environments: some 10 million living prototypes (i.e., estimated number of existing plants and animals) for engineers. The complexity of the hierarchical structures and their functionality in biological organisms surpasses all abiotic natural surfaces: even superhydrophobicity is restricted in nature to living organisms and was probably a key evolutionary step with the invasion of terrestrial habitats some 350-450 million years ago in plants and insects. Special attention should be paid to the fact that global environmental change implies a dramatic loss of species and with it the biological role models. Plants, the dominating group of organisms on our planet, are sessile organisms with large multifunctional surfaces and thus exhibit particular intriguing features. Superhydrophilicity and superhydrophobicity are focal points in this work. We estimate that superhydrophobic plant leaves (e.g., grasses) comprise in total an area of around 250 million km2, which is about 50% of the total surface of our planet. A survey of structures and functions based on own examinations of almost 20,000 species is provided, for further references we refer to Barthlott et al. (Philos. Trans. R. Soc. A 374: 20160191, 1). A basic difference exists between aquatic non-vascular and land-living vascular plants; the latter exhibit a particular intriguing surface chemistry and architecture. The diversity of features is described in detail according to their hierarchical structural order. The first underlying and essential feature is the polymer cuticle superimposed by epicuticular wax and the curvature of single cells up to complex multicellular structures. A descriptive terminology

Deterministically patterned biomimetic human iPSC-derived hepatic model via rapid 3D bioprinting

PubMed Central

Ma, Xuanyi; Qu, Xin; Zhu, Wei; Li, Yi-Shuan; Yuan, Suli; Zhang, Hong; Liu, Justin; Wang, Pengrui; Lai, Cheuk Sun Edwin; Zanella, Fabian; Feng, Gen-Sheng; Sheikh, Farah; Chien, Shu; Chen, Shaochen

2016-01-01

The functional maturation and preservation of hepatic cells derived from human induced pluripotent stem cells (hiPSCs) are essential to personalized in vitro drug screening and disease study. Major liver functions are tightly linked to the 3D assembly of hepatocytes, with the supporting cell types from both endodermal and mesodermal origins in a hexagonal lobule unit. Although there are many reports on functional 2D cell differentiation, few studies have demonstrated the in vitro maturation of hiPSC-derived hepatic progenitor cells (hiPSC-HPCs) in a 3D environment that depicts the physiologically relevant cell combination and microarchitecture. The application of rapid, digital 3D bioprinting to tissue engineering has allowed 3D patterning of multiple cell types in a predefined biomimetic manner. Here we present a 3D hydrogel-based triculture model that embeds hiPSC-HPCs with human umbilical vein endothelial cells and adipose-derived stem cells in a microscale hexagonal architecture. In comparison with 2D monolayer culture and a 3D HPC-only model, our 3D triculture model shows both phenotypic and functional enhancements in the hiPSC-HPCs over weeks of in vitro culture. Specifically, we find improved morphological organization, higher liver-specific gene expression levels, increased metabolic product secretion, and enhanced cytochrome P450 induction. The application of bioprinting technology in tissue engineering enables the development of a 3D biomimetic liver model that recapitulates the native liver module architecture and could be used for various applications such as early drug screening and disease modeling. PMID:26858399

Deterministically patterned biomimetic human iPSC-derived hepatic model via rapid 3D bioprinting.

PubMed

Ma, Xuanyi; Qu, Xin; Zhu, Wei; Li, Yi-Shuan; Yuan, Suli; Zhang, Hong; Liu, Justin; Wang, Pengrui; Lai, Cheuk Sun Edwin; Zanella, Fabian; Feng, Gen-Sheng; Sheikh, Farah; Chien, Shu; Chen, Shaochen

2016-02-23

The functional maturation and preservation of hepatic cells derived from human induced pluripotent stem cells (hiPSCs) are essential to personalized in vitro drug screening and disease study. Major liver functions are tightly linked to the 3D assembly of hepatocytes, with the supporting cell types from both endodermal and mesodermal origins in a hexagonal lobule unit. Although there are many reports on functional 2D cell differentiation, few studies have demonstrated the in vitro maturation of hiPSC-derived hepatic progenitor cells (hiPSC-HPCs) in a 3D environment that depicts the physiologically relevant cell combination and microarchitecture. The application of rapid, digital 3D bioprinting to tissue engineering has allowed 3D patterning of multiple cell types in a predefined biomimetic manner. Here we present a 3D hydrogel-based triculture model that embeds hiPSC-HPCs with human umbilical vein endothelial cells and adipose-derived stem cells in a microscale hexagonal architecture. In comparison with 2D monolayer culture and a 3D HPC-only model, our 3D triculture model shows both phenotypic and functional enhancements in the hiPSC-HPCs over weeks of in vitro culture. Specifically, we find improved morphological organization, higher liver-specific gene expression levels, increased metabolic product secretion, and enhanced cytochrome P450 induction. The application of bioprinting technology in tissue engineering enables the development of a 3D biomimetic liver model that recapitulates the native liver module architecture and could be used for various applications such as early drug screening and disease modeling.

An Investigation into the Effects of Interface Stress and Interfacial Arrangement on Temperature Dependent Thermal Properties of a Biological and a Biomimetic Material

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

Tomar, Vikas

2015-01-12

A significant effort in the biomimetic materials research is on developing materials that can mimic and function in the same way as biological tissues, on bio-inspired electronic circuits, on bio-inspired flight structures, on bio-mimetic materials processing, and on structural biomimetic materials, etc. Most structural biological and biomimetic material properties are affected by two primary factors: (1) interfacial interactions between an organic and an inorganic phase usually in the form of interactions between an inorganic mineral phase and organic protein network; and (2) structural arrangement of the constituents. Examples are exoskeleton structures such as spicule, nacre, and crustacean exoskeletons. A significantmore » effort is being directed towards making synthetic biomimetic materials based on a manipulation of the above two primary factors. The proposed research is based on a hypothesis that in synthetic materials with biomimetic morphology thermal conductivity, k, (how fast heat is carried away) and thermal diffusivity, D, (how fast a material’s temperature rises: proportional to the ratio of k and heat capacity) can be engineered to be either significantly low or significantly high based on a combination of chosen interface orientation and interfacial arrangement in comparison to conventional material microstructures with the same phases and phase volume fractions. METHOD DEVELOPMENT 1. We have established a combined Raman spectroscopy and nanomechanical loading based experimental framework to perform environment (liquid vs. air vs. vacuum) dependent and temperature dependent (~1000 degree-C) in-situ thermal diffusivity measurements in biomaterials at nanoscale to micron scale along with the corresponding analytical theoretic calculations. (Zhang and Tomar, 2013) 2. We have also established a new classical molecular simulation based framework to measure thermal diffusivity in biomolecular interfaces. We are writing a publication currently (Qu and

Surface modification using the biomimetic method in alumina-zirconia porous ceramics obtained by the replica method.

PubMed

Silva, André D R; Rigoli, Willian R; Osiro, Denise; Mello, Daphne C R; Vasconcellos, Luana M R; Lobo, Anderson O; Pallone, Eliria M J A

2018-01-12

The modification of biomaterials approved by the Food and Drug Administration could be an alternative to reduce the period of use in humans. Porous bioceramics are widely used as support structures for bone formation and repair. This composite has essential characteristics for an implant, including good mechanical properties, high chemical stability, biocompatibility and adequate aesthetic appearance. Here, three-dimensional porous scaffolds of Al 2 O 3 containing 5% by volume of ZrO 2 were produced by the replica method. These scaffolds had their surfaces chemically treated with phosphoric acid and were coated with calcium phosphate using the biomimetic method simulated body fluid (SBF, 5×) for 14 days. The scaffolds, before and after biomimetic coating, were characterized mechanically, morphologically and structurally by axial compression tests, scanning electron microscopy, microtomography, apparent porosity, X-ray diffractometry, near-infrared spectroscopy, inductively coupled plasma optical emission spectroscopy, energy dispersive X-ray spectroscopy and reactivity. The in vitro cell viability and formation of mineralization nodules were used to identify the potential for bone regeneration. The produced scaffols after immersion in SBF were able to induce the nodules formation. These characteristics are advantaged by the formation of different phases of calcium phosphates on the material surface in a reduced incubation period. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc.

Biomimetic hydrogel with tunable mechanical properties for vitreous substitutes.

PubMed

Santhanam, Sruthi; Liang, Jue; Struckhoff, Jessica; Hamilton, Paul D; Ravi, Nathan

2016-10-01

The vitreous humor of the eye is a biological hydrogel principally composed of collagen fibers interspersed with hyaluronic acid. Certain pathological conditions necessitate its removal and replacement. Current substitutes, like silicone oils and perfluorocarbons, are not biomimetic and have known complications. In this study, we have developed an in situ forming two-component biomimetic hydrogel with tunable mechanical and osmotic properties. The components are gellan, an analogue of collagen, and poly(methacrylamide-co-methacrylate), an analogue of hyaluronic acid; both endowed with thiol side groups. We used response surface methodology to consider seventeen possible hydrogels to determine how each component affects the optical, mechanical, sol-gel transition temperature and swelling properties. The optical and physical properties of the hydrogels were similar to vitreous. The shear storage moduli ranged from 3 to 358Pa at 1Hz and sol-gel transition temperatures from 35.5 to 43°C. The hydrogel had the ability to remain swollen without degradation for four weeks in vitro. Three hydrogels were tested for biocompatibility on primary porcine retinal pigment epithelial cells, human retinal pigment epithelial cells, and fibroblast (3T3/NIH) cells, by electric cell-substrate impedance sensing system. The two-component hydrogels allowed for the tuning and optimizing of mechanical, swelling, and transition temperature to obtain three biocompatible hydrogels with properties similar to the vitreous. Future studies include testing of the optimized hydrogels in animal models for use as a long-term substitute, whose preliminary results are mentioned. Although hydrogels are researched as long-term vitreous substitute, none have advanced sufficiently to reach clinical application. Our work focuses on the development of a novel two component in situ forming hydrogel that bio-mimic the natural vitreous. Our thiol-containing copolymers can be injected as an aqueous solution into

Development of Multi-Legged Walking Robot Using Reconfigurable Modular Design and Biomimetic Control Architecture

NASA Astrophysics Data System (ADS)

Chen, Xuedong; Sun, Yi; Huang, Qingjiu; Jia, Wenchuan; Pu, Huayan

This paper focuses on the design of a modular multi-legged walking robot MiniQuad-I, which can be reconfigured into variety configurations, including quadruped and hexapod configurations for different tasks by changing the layout of modules. Critical design considerations when taking the adaptability, maintainability and extensibility in count simultaneously are discussed and then detailed designs of each module are presented. The biomimetic control architecture of MiniQuad-I is proposed, which can improve the capability of agility and independence of the robot. Simulations and experiments on crawling, object picking and obstacle avoiding are performed to verify functions of the MiniQuad-I.

Directed Fluid Transport with Biomimetic ``Silia'' Arrays

NASA Astrophysics Data System (ADS)

Shields, A. R.; Evans, B. A.; Carstens, B. L.; Falvo, M. R.; Washburn, S.; Superfine, R.

2008-10-01

We present results on the long-range, directed fluid transport produced by the collective beating of arrays of biomimetic ``silia.'' Silia are arrays of free-standing nanorods roughly the size of biological cilia, which we fabricate from a polymer-magnetic nanoparticle composite material. With external permanent magnets we actuate our silia such that their motion mimics the beating of biological cilia. Biological cilia have evolved to produce microscale fluid transport and are increasingly being recognized as critical components in a wide range of biological systems. However, despite much effort cilia generated fluid flows remain an area of active study. In the last decade, cilia-driven fluid flow in the embryonic node of vertebrates has been implicated as the initial left-right symmetry breaking event in these embryos. With silia we generate directional fluid transport by mimicking the tilted conical beating of these nodal cilia and seek to answer open questions about the nature of particle advection in such a system. By seeding fluorescent microparticles into the fluid we have noted the existence of two distinct flow regimes. The fluid flow is directional and coherent above the tips of the silia, while between the silia tips and floor particle motion is complicated and suggestive of chaotic advection.

Selected papers from the 7th International Conference on Biomimetics, Artificial Muscles and Nano-bio (BAMN2013)

NASA Astrophysics Data System (ADS)

Shahinpoor, Mohsen; Oh, Ilkwon

2014-07-01

The 7th International Congress on Biomimetics, Artificial Muscles and Nano-Bio was held on the magnificent and beautiful Jeju Island in Korea on 26-30 August 2013. In June 2007, the volcanic island and lava tube cave systems were designated as UNESCO World Natural Heritage Sites for their natural beauty and unique geographical values. The aim of the congress was to offer high-level lectures, extensive discussions and communications covering the state-of-the-art on biomimetics, artificial muscles, and nano-bio technologies providing an overview of their potential applications in the industrial, biomedical, scientific and robotic fields. This conference provided a necessary platform for an ongoing dialogue between researchers from different areas (chemistry, physics, biology, medicine, engineering, robotics, etc) within biomimetics, artificial muscle and nano-bio technologies. This special issue of Smart Materials and Structures is devoted to a selected number of research papers that were presented at BAMN2013. Of the 400 or so papers and over 220 posters presented at this international congress, 15 papers were finally received, reviewed and accepted for this special issue, following the regular peer review procedures of the journal. The special issue covers polymeric artificial muscles, electroactive polymers, multifunctional nanocomposites, and their applications. In particular, electromechanical performance and other characteristics of ionic polymer-metal composites (IPMCs) fabricated with various commercially available ion exchange membranes are discussed. Additionally, the control of free-edge interlaminar stresses in composite laminates using piezoelectric actuators is elaborated on. Further, the electrode effects of a cellulose-based electroactive paper energy harvester are described. Next, a flexible tactile-feedback touch screen using transparent ferroelectric polymer film vibrators is discussed. A broad coverage of bio-applications of IPMC transducers is

Towards low back support with a passive biomimetic exo-spine.

PubMed

Naf, Matthias B; De Rijcke, Laura; Guerrero, Carlos Rodriguez; Millard, Matthew; Vanderborght, Bram; Lefeber, Dirk

2017-07-01

Low-Back Pain (LBP) affects a large portion of the working population. Preventive exoskeletons have been proposed to reduce the moments on the lower back, specifically around the lumbosacral (L5/S1) joint. High correlation has been shown, between reducing the moments around the L5/S1 joint and intervertebral compression forces, which in turn have been identified as a risk factor for developing LBP. However, most passive back support exoskeletons use rigid plates or stiff beams to support the spine that limit the range of motion of the wearer. A large range of motion and versatility are especially desirable for industrial applications. To overcome these limitations, a passive biomimetic exo-spine has been designed, modelled and an initial prototype tested. Its potential to allow for a large range of motion, whilst at the same time limiting the most extreme and potentially harmful postures has been shown.

A Novel Biomimetic Nanosponge Protects the Retina from the Enterococcus faecalis Cytolysin.

PubMed

LaGrow, Austin L; Coburn, Phillip S; Miller, Frederick C; Land, Craig; Parkunan, Salai Madhumathi; Luk, Brian T; Gao, Weiwei; Zhang, Liangfang; Callegan, Michelle C

2017-01-01

Intraocular infections are a potentially blinding complication of common ocular surgeries and traumatic eye injuries. Bacterial toxins synthesized in the eye can damage intraocular tissue, often resulting in poor visual outcomes. Enteroccocus faecalis causes blinding infections and is responsible for 8 to 17% of postoperative endophthalmitis cases. These infections are increasingly difficult to treat due to the emergence of multidrug-resistant strains. Virulent E. faecalis isolates secrete a pore-forming bicomponent cytolysin that contributes to retinal tissue damage during endophthalmitis. We hypothesized that a biomimetic nanosponge, which mimics erythrocytes, might adsorb subunits of the cytolysin and reduce retinal damage, protecting vision. To test the efficacy of nanosponges in neutralizing the cytolysin in vitro , hemoglobin release assays were performed on culture supernatants from cytolysin-producing E. faecalis with and without preincubation with nanosponges. Treatment with nanosponges for 30 min reduced hemolytic activity by ~70%. To determine whether nanosponges could neutralize the cytolysin in vivo , electroretinography was performed on mice 24 h after intravitreal injection with cytolysin-containing supernatants treated with nanosponges. Pretreatment of cytolysin-containing supernatants with nanosponges increased the A-wave retention from 12.2% to 65.5% and increased the B-wave retention from 21.0% to 77.0%. Histology revealed that in nanosponge-treated eyes, retinas remained intact and attached, with little to no damage. Rabbit nanosponges were also nontoxic and noninflammatory when injected into mouse eyes. In an experimental murine model of E. faecalis endophthalmitis, injection of nanosponges into the vitreous 6 h after infection with a wild-type cytolysin-producing strain increased A-wave retention from 5.9% to 31% and increased B-wave retention from 12.6% to 27.8%. Together, these results demonstrated that biomimetic nanosponges

A Novel Biomimetic Nanosponge Protects the Retina from the Enterococcus faecalis Cytolysin

PubMed Central

LaGrow, Austin L.; Coburn, Phillip S.; Miller, Frederick C.; Land, Craig; Parkunan, Salai Madhumathi; Luk, Brian T.; Gao, Weiwei; Zhang, Liangfang

2017-01-01

ABSTRACT Intraocular infections are a potentially blinding complication of common ocular surgeries and traumatic eye injuries. Bacterial toxins synthesized in the eye can damage intraocular tissue, often resulting in poor visual outcomes. Enteroccocus faecalis causes blinding infections and is responsible for 8 to 17% of postoperative endophthalmitis cases. These infections are increasingly difficult to treat due to the emergence of multidrug-resistant strains. Virulent E. faecalis isolates secrete a pore-forming bicomponent cytolysin that contributes to retinal tissue damage during endophthalmitis. We hypothesized that a biomimetic nanosponge, which mimics erythrocytes, might adsorb subunits of the cytolysin and reduce retinal damage, protecting vision. To test the efficacy of nanosponges in neutralizing the cytolysin in vitro, hemoglobin release assays were performed on culture supernatants from cytolysin-producing E. faecalis with and without preincubation with nanosponges. Treatment with nanosponges for 30 min reduced hemolytic activity by ~70%. To determine whether nanosponges could neutralize the cytolysin in vivo, electroretinography was performed on mice 24 h after intravitreal injection with cytolysin-containing supernatants treated with nanosponges. Pretreatment of cytolysin-containing supernatants with nanosponges increased the A-wave retention from 12.2% to 65.5% and increased the B-wave retention from 21.0% to 77.0%. Histology revealed that in nanosponge-treated eyes, retinas remained intact and attached, with little to no damage. Rabbit nanosponges were also nontoxic and noninflammatory when injected into mouse eyes. In an experimental murine model of E. faecalis endophthalmitis, injection of nanosponges into the vitreous 6 h after infection with a wild-type cytolysin-producing strain increased A-wave retention from 5.9% to 31% and increased B-wave retention from 12.6% to 27.8%. Together, these results demonstrated that biomimetic nanosponges

A biomimetic colorimetric logic gate system based on multi-functional peptide-mediated gold nanoparticle assembly

NASA Astrophysics Data System (ADS)

Li, Yong; Li, Wang; He, Kai-Yu; Li, Pei; Huang, Yan; Nie, Zhou; Yao, Shou-Zhuo

2016-04-01

In natural biological systems, proteins exploit various functional peptide motifs to exert target response and activity switch, providing a functional and logic basis for complex cellular activities. Building biomimetic peptide-based bio-logic systems is highly intriguing but remains relatively unexplored due to limited logic recognition elements and complex signal outputs. In this proof-of-principle work, we attempted to address these problems by utilizing multi-functional peptide probes and the peptide-mediated nanoparticle assembly system. Here, the rationally designed peptide probes function as the dual-target responsive element specifically responsive to metal ions and enzymes as well as the mediator regulating the assembly of gold nanoparticles (AuNPs). Taking advantage of Zn2+ ions and chymotrypsin as the model inputs of metal ions and enzymes, respectively, we constructed the peptide logic system computed by the multi-functional peptide probes and outputted by the readable colour change of AuNPs. In this way, the representative binary basic logic gates (AND, OR, INHIBIT, NAND, IMPLICATION) have been achieved by delicately coding the peptide sequence, demonstrating the versatility of our logic system. Additionally, we demonstrated that the three-input combinational logic gate (INHIBIT-OR) could also be successfully integrated and applied as a multi-tasking biosensor for colorimetric detection of dual targets. This nanoparticle-based peptide logic system presents a valid strategy to illustrate peptide information processing and provides a practical platform for executing peptide computing or peptide-related multiplexing sensing, implying that the controllable nanomaterial assembly is a promising and potent methodology for the advancement of biomimetic bio-logic computation.In natural biological systems, proteins exploit various functional peptide motifs to exert target response and activity switch, providing a functional and logic basis for complex cellular

A multi-electrode biomimetic electrolocation sensor

NASA Astrophysics Data System (ADS)

Mayekar, K.; Damalla, D.; Gottwald, M.; Bousack, H.; von der Emde, G.

2012-04-01

We present the concept of an active multi-electrode catheter inspired by the electroreceptive system of the weakly electric fish, Gnathonemus petersii. The skin of this fish exhibits numerous electroreceptor organs which are capable of sensing a self induced electrical field. Our sensor is composed of a sending electrode and sixteen receiving electrodes. The electrical field produced by the sending electrode was measured by the receiving electrodes and objects were detected by the perturbation of the electrical field they induce. The intended application of such a sensor is in coronary diagnostics, in particular in distinguishing various types of plaques, which are major causes of heart attack. For calibration of the sensor system, finite element modeling (FEM) was performed. To validate the model, experimental measurements were carried out with two different systems. The physical system was glass tubing with metal and plastic wall insertions as targets. For the control of the experiment and for data acquisition, the software LabView designed for 17 electrodes was used. Different parameters of the electric images were analyzed for the prediction of the electrical properties and size of the inserted targets in the tube. Comparisons of the voltage modulations predicted from the FEM model and the experiments showed a good correspondence. It can be concluded that this novel biomimetic method can be further developed for detailed investigations of atherosclerotic lesions. Finally, we discuss various design strategies to optimize the output of the sensor using different simulated models to enhance target recognition.

Sequentially-crosslinked biomimetic bioactive glass/gelatin methacryloyl composites hydrogels for bone regeneration.

PubMed

Zheng, Jiafu; Zhao, Fujian; Zhang, Wen; Mo, Yunfei; Zeng, Lei; Li, Xian; Chen, Xiaofeng

2018-08-01

In recent years, gelatin-based composites hydrogels have been intensively investigated because of their inherent bioactivity, biocompatibility and biodegradability. Herein, we fabricated photocrosslinkable biomimetic composites hydrogels from bioactive glass (BG) and gelatin methacryloyl (GelMA) by a sequential physical and chemical crosslinking (gelation + UV) approach. The results showed that the compressive modulus of composites hydrogels increased significantly through the sequential crosslinking approach. The addition of BG resulted in a significant increase in physiological stability and apatite-forming ability. In vitro data indicated that BG/GelMA composites hydrogels promoted cell attachment, proliferation and differentiation. Overall, the BG/GelMA composites hydrogels combined the advantages of good biocompatibility and bioactivity, and had potential applications in bone regeneration. Copyright © 2018. Published by Elsevier B.V.

On the need for a biomimetic breast device

NASA Astrophysics Data System (ADS)

Danos, Nicole; German, Rebecca

2016-11-01

The function of the mammary gland, a key anatomical innovation that led to the rise of mammals, is governed by solid-fluid mechanics. There is strong evidence that these mechanical interactions regulate the production of milk and the transport of milk through the lactiferous ducts and into the infant's mouth. Solid-fluid mechanics determine the rate of milk flow and therefore may affect the safe coordination of sucking, swallowing and breathing in the infant. Additionally, links between breastfeeding, the material properties of the gland and breast cancer have been shown repeatedly. However, there is to date no direct way of characterizing breast mechanics during the physiological function for which it has evolved: infant feeding. We are developing an engineered biomimetic breast in which we can experimentally manipulate both structural and material properties of the gland. The device will be tested with an animal model of infant feeding, the pig, to measure the direct effect of gland mechanics on infant feeding. Data from these studies may lead to better designed feeding bottles for infants, milk pumps for both humans and agricultural mammals, and will provide the control mechanical environmental for studies of breast cancer mechanobiology.

Simulation of Biomimetic Recognition between Polymers and Surfaces

NASA Astrophysics Data System (ADS)

Golumbfskie, Aaron J.; Pande, Vijay S.; Chakraborty, Arup K.

1999-10-01

Many biological processes, such as transmembrane signaling and pathogen-host interactions, are initiated by a protein recognizing a specific pattern of binding sites on part of a membrane or cell surface. By recognition, we imply that the polymer quickly finds and then adsorbs strongly on the pattern-matched region and not on others. The development of synthetic systems that can mimic such recognition between polymers and surfaces could have significant impact on advanced applications such as the development of sensors, molecular-scale separation processes, and synthetic viral inhibition agents. Attempting to affect recognition in synthetic systems by copying the detailed chemistries to which nature has been led over millenia of evolution does not seem practical for most applications. This leads us to the following question: Are there any universal strategies that can affect recognition between polymers and surfaces? Such generic strategies may be easier to implement in abiotic applications. We describe results that suggest that biomimetic recognition between synthetic polymers and surfaces is possible by exploiting certain generic strategies, and we elucidate the kinetic mechanisms by which this occurs. Our results suggest convenient model systems for experimental studies of dynamics in free energy landscapes characteristic of frustrated systems.

Measuring shear force transmission across a biomimetic glycocalyx

NASA Astrophysics Data System (ADS)

Bray, Isabel; Young, Dylan; Scrimgeour, Jan

Human blood vessels are lined with a low-density polymer brush known as the glycocalyx. This brush plays an active role in defining the mechanical and biochemical environment of the endothelial cell in the blood vessel wall. In addition, it is involved in the detection of mechanical stimuli, such as the shear stress from blood flowing in the vessel. In this work, we construct a biomimetic version of the glycocalyx on top of a soft deformable substrate in order to measure its ability to modulate the effects of shear stress at the endothelial cell surface. The soft substrate is stamped on to a glass substrate and then enclosed inside a microfluidic device that generates a controlled flow over the substrate. The hydrogel chemistry has been optimized so that it reliably stamps into a defined shape and has consistent mechanical properties. Fluorescent microbeads embedded in the gel allow measurement of the surface deformation, and subsequently, calculation of the shear force at the surface of the soft substrate. We investigate the effect of the major structural elements of the glycocalyx, hyaluronic acid and charged proteoglycans, on the magnitude of the shear force transmitted to the surface of the hydrogel.

Biomimetic and bio-inspired uses of mollusc shells.

PubMed

Morris, J P; Wang, Y; Backeljau, T; Chapelle, G

2016-06-01

Climate change and ocean acidification are likely to have a profound effect on marine molluscs, which are of great ecological and economic importance. One process particularly sensitive to climate change is the formation of biominerals in mollusc shells. Fundamental research is broadening our understanding of the biomineralization process, as well as providing more informed predictions on the effects of climate change on marine molluscs. Such studies are important in their own right, but their value also extends to applied sciences. Biominerals, organic/inorganic hybrid materials with many remarkable physical and chemical properties, have been studied for decades, and the possibilities for future improved use of such materials for society are widely recognised. This article highlights the potential use of our understanding of the shell biomineralization process in novel bio-inspired and biomimetic applications. It also highlights the potential for the valorisation of shells produced as a by-product of the aquaculture industry. Studying shells and the formation of biominerals will inspire novel functional hybrid materials. It may also provide sustainable, ecologically- and economically-viable solutions to some of the problems created by current human resource exploitation. Copyright © 2016 Elsevier B.V. All rights reserved.

A biomimetic vision-based hovercraft accounts for bees' complex behaviour in various corridors.

PubMed

Roubieu, Frédéric L; Serres, Julien R; Colonnier, Fabien; Franceschini, Nicolas; Viollet, Stéphane; Ruffier, Franck

2014-09-01

Here we present the first systematic comparison between the visual guidance behaviour of a biomimetic robot and those of honeybees flying in similar environments. We built a miniature hovercraft which can travel safely along corridors with various configurations. For the first time, we implemented on a real physical robot the 'lateral optic flow regulation autopilot', which we previously studied computer simulations. This autopilot inspired by the results of experiments on various species of hymenoptera consists of two intertwined feedback loops, the speed and lateral control loops, each of which has its own optic flow (OF) set-point. A heading-lock system makes the robot move straight ahead as fast as 69 cm s(-1) with a clearance from one wall as small as 31 cm, giving an unusually high translational OF value (125° s(-1)). Our biomimetic robot was found to navigate safely along straight, tapered and bent corridors, and to react appropriately to perturbations such as the lack of texture on one wall, the presence of a tapering or non-stationary section of the corridor and even a sloping terrain equivalent to a wind disturbance. The front end of the visual system consists of only two local motion sensors (LMS), one on each side. This minimalistic visual system measuring the lateral OF suffices to control both the robot's forward speed and its clearance from the walls without ever measuring any speeds or distances. We added two additional LMSs oriented at +/-45° to improve the robot's performances in stiffly tapered corridors. The simple control system accounts for worker bees' ability to navigate safely in six challenging environments: straight corridors, single walls, tapered corridors, straight corridors with part of one wall moving or missing, as well as in the presence of wind.

Biomimetic Engineering of Nanofibrous Gelatin Scaffolds with Noncollagenous Proteins for Enhanced Bone Regeneration

PubMed Central

Sun, Yao; Jiang, Yong; Liu, Qilin; Gao, Tian; Feng, Jian Q.; Dechow, Paul; D'Souza, Rena N.; Qin, Chunlin

2013-01-01

Biomimetic approaches are widely used in scaffolding designs to enhance tissue regeneration. In this study, we integrated noncollagenous proteins (NCPs) from bone extracellular matrix (ECM) with three-dimensional nanofibrous gelatin (NF-Gelatin) scaffolds to form an artificial matrix (NF-Gelatin-NCPs) mimicking both the nano-structured architecture and chemical composition of natural bone ECM. Through a chemical coupling process, the NCPs were evenly distributed over all the surfaces (inner and outer) of the NF-gelatin-NCPs. The in vitro study showed that the number of osteoblasts (MC3T3-E1) on the NF-Gelatin-NCPs was significantly higher than that on the NF-Gelatin after being cultured for 14 days. Both the alkaline phosphatase (ALP) activity and the expression of osteogenic genes (OPN, BSP, DMP1, CON, and Runx2) were significantly higher in the NF-Gelatin-NCPs than in the NF-Gelatin at 3 weeks. Von Kossa staining, backscattered scanning electron microscopy, and microcomputed tomography all revealed a higher amount of mineral deposition in the NF-Gelatin-NCPs than in the NF-Gelatin after in vitro culturing for 3 weeks. The in vivo calvarial defect study indicated that the NF-Gelatin-NCPs recruited more host cells to the defect and regenerated a higher amount of bone than the controls after implantation for 6 weeks. Immunohistochemical staining also showed high-level mineralization of the bone matrix in the NF-Gelatin-NCPs. Taken together, both the in vitro and in vivo results confirmed that the incorporation of NCPs onto the surfaces of the NF-Gelatin scaffold significantly enhanced osteogenesis and mineralization. Biomimetic engineering of the surfaces of the NF-Gelatin scaffold with NCPs, therefore, is a promising strategy to enhance bone regeneration. PMID:23469769

Biomimetic MEMS to assist, enhance, and expand human sensory perceptions: a survey on state-of-the-art developments

NASA Astrophysics Data System (ADS)

Makarczuk, Teresa; Matin, Tina R.; Karman, Salmah B.; Diah, S. Zaleha M.; Davaji, Benyamin; Macqueen, Mark O.; Mueller, Jeanette; Schmid, Ulrich; Gebeshuber, Ille C.

2011-06-01

The human senses are of extraordinary value but we cannot change them even if this proves to be a disadvantage in modern times. However, we can assist, enhance and expand these senses via MEMS. Current MEMS cover the range of the human sensory system, and additionally provide data about signals that are too weak for the human sensory system (in terms of signal strength) and signal types that are not covered by the human sensory system. Biomimetics deals with knowledge transfer from biology to technology. In our interdisciplinary approach existing MEMS sensor designs shall be modified and adapted (to keep costs at bay), via biomimetic knowledge transfer of outstanding sensory perception in 'best practice' organisms (e.g. thermoreception, UV sensing, electromagnetic sense). The MEMS shall then be linked to the human body (mainly ex corpore to avoid ethics conflicts), to assist, enhance and expand human sensory perception. This paper gives an overview of senses in humans and animals, respective MEMS sensors that are already on the market and gives a list of possible applications of such devices including sensors that vibrate when a blind person approaches a kerb stone edge and devices that allow divers better orientation under water (echolocation, ultrasound).

Interfacing of differential-capacitive biomimetic hair flow-sensors for optimal sensitivity

NASA Astrophysics Data System (ADS)

Dagamseh, A. M. K.; Bruinink, C. M.; Wiegerink, R. J.; Lammerink, T. S. J.; Droogendijk, H.; Krijnen, G. J. M.

2013-03-01

Biologically inspired sensor-designs are investigated as a possible path to surpass the performance of more traditionally engineered designs. Inspired by crickets, artificial hair sensors have shown the ability to detect minute flow signals. This paper addresses developments in the design, fabrication, interfacing and characterization of biomimetic hair flow-sensors towards sensitive high-density arrays. Improvement of the electrode design of the hair sensors has resulted in a reduction of the smallest hair movements that can be measured. In comparison to the arrayed hairs-sensor design, the detection-limit was arguably improved at least twelve-fold, down to 1 mm s-1 airflow amplitude at 250 Hz as measured in a bandwidth of 3 kHz. The directivity pattern closely resembles a figure-of-eight. These sensitive hair-sensors open possibilities for high-resolution spatio-temporal flow pattern observations.

Biomimetic Moth-eye Nanofabrication: Enhanced Antireflection with Superior Self-cleaning Characteristic.

PubMed

Sun, Jingyao; Wang, Xiaobing; Wu, Jinghua; Jiang, Chong; Shen, Jingjing; Cooper, Merideth A; Zheng, Xiuting; Liu, Ying; Yang, Zhaogang; Wu, Daming

2018-04-03

Sub-wavelength antireflection moth-eye structures were fabricated with Nickel mold using Roll-to-Plate (R2P) ultraviolet nanoimprint lithography (UV-NIL) on transparent polycarbonate (PC) substrates. Samples with well replicated patterns established an average reflection of 1.21% in the visible light range, 380 to 760 nm, at normal incidence. An excellent antireflection property of a wide range of incidence angles was shown with the average reflection below 4% at 50°. Compared with the unpatterned ultraviolet-curable resin coating, the resulting sub-wavelength moth-eye structure also exhibited increased hydrophobicity in addition to antireflection. This R2P method is especially suitable for large-area product preparation and the biomimetic moth-eye structure with multiple performances can be applied to optical devices such as display screens, solar cells, or light emitting diodes.

Block Copolymer Directed Biomimetic Mineral Formation for Polymer Nanocomposites

NASA Astrophysics Data System (ADS)

Gleeson, Sarah; Yu, Tony; Chen, Xi; Marcolongo, Michele; Li, Christopher

Bone is a hierarchically structured biocomposite comprised of mineralized collagen fibrils. The mechanical properties of bone can be precisely tuned by the structure and morphology of the mineral nanocrystals as well as the organic collagen fibrils. Synthetic materials that can mimic the nanostructure of natural bone show promise to replicate bone's structural function, yet little is known about the mechanism of mineral formation. We previously have shown that hierarchically ordered polymer fibers control the distribution and orientation of hydroxyapatite, enhancing mechanical properties and biocompatibility. We demonstrate a new method for mineralization by forming block copolymer single crystal films of polycaprolactone-block-poly(acrylic acid) (PCL- b-PAA) so that lamellar anionic PAA nanodomains recruit mineral ions and provide one-dimensional confinement to induce orientation. The effect of the anionic domain dimensions on mineral content, orientation, and structure within the polymer matrix is shown. The mechanical properties of the nanocomposite are evaluated to determine the role of mineral orientation and crystallinity in composite strength. These results can be used to tailor the physical mineralization environment to create a more biomimetic bone material.

Modeling of dielectric elastomer oscillators for soft biomimetic applications.

PubMed

Henke, E-F M; Wilson, Katherine E; Anderson, I A

2018-06-26

Biomimetic, entirely soft robots with animal-like behavior and integrated artificial nervous systems will open up totally new perspectives and applications. However, until now, most presented studies on soft robots were limited to only partly soft designs, since all solutions at least needed conventional, stiff electronics to sense, process signals and activate actuators. We present a novel approach for a set up and the experimental validation of an artificial pace maker that is able to drive basic robotic structures and act as artificial central pattern generator. The structure is based on multi-functional dielectric elastomers (DEs). DE actuators, DE switches and DE resistors are combined to create complex DE oscillators (DEOs). Supplied with only one external DC voltage, the DEO autonomously generates oscillating signals that can be used to clock a robotic structure, control the cyclic motion of artificial muscles in bionic robots or make a whole robotic structure move. We present the basic functionality, derive a mathematical model for predicting the generated signal waveform and verify the model experimentally.

Biomimetic and bioactive nanofibrous scaffolds from electrospun composite nanofibers

PubMed Central

Zhang, YZ; Su, B; Venugopal, J; Ramakrishna, S; Lim, CT

2007-01-01

Electrospinning is an enabling technology that can architecturally (in terms of geometry, morphology or topography) and biochemically fabricate engineered cellular scaffolds that mimic the native extracellular matrix (ECM). This is especially important and forms one of the essential paradigms in the area of tissue engineering. While biomimesis of the physical dimensions of native ECM’s major constituents (eg, collagen) is no longer a fabrication-related challenge in tissue engineering research, conveying bioactivity to electrospun nanofibrous structures will determine the efficiency of utilizing electrospun nanofibers for regenerating biologically functional tissues. This can certainly be achieved through developing composite nanofibers. This article gives a brief overview on the current development and application status of employing electrospun composite nanofibers for constructing biomimetic and bioactive tissue scaffolds. Considering that composites consist of at least two material components and phases, this review details three different configurations of nanofibrous composite structures by using hybridizing basic binary material systems as example. These are components blended composite nanofiber, core-shell structured composite nanofiber, and nanofibrous mingled structure. PMID:18203429

Actuation control of a PiezoMEMS biomimetic robotic jellyfish

NASA Astrophysics Data System (ADS)

Alejandre, Alvaro; Olszewski, Oskar; Jackson, Nathan

2017-06-01

Biomimetic micro-robots try to mimic the motion of a living system in the form of a synthetically developed microfabricated device. Dynamic motion of living systems have evolved through the years, but trying to mimic these motions is challenging. Micro-robotics are particular challenging as the fabrication of devices and controlling the motion in 3 dimensions is difficult. However, micro-scale robotics have potential to be used in a wide range of applications. MEMS based robots that can move and function in a liquid environment is of particular interest. This paper describes the development of a piezoMEMS based device that mimics the movement of a jellyfish. The paper focuses on the development of a finite element model that investigates a method of controlling the individual piezoelectric beams in order to create a jet propulsion motion, consisting of a quick excitation pulse followed by a slow recovery pulse in order to maximize thrust and velocity. By controlling the individual beams or legs of the jellyfish robot the authors can control the robot to move precisely in 3 dimensions.

Biomimetic three-dimensional nanocrystalline hydroxyapatite and magnetically synthesized single-walled carbon nanotube chitosan nanocomposite for bone regeneration

PubMed Central

Im, Owen; Li, Jian; Wang, Mian; Zhang, Lijie Grace; Keidar, Michael

2012-01-01

Background Many shortcomings exist in the traditional methods of treating bone defects, such as donor tissue shortages for autografts and disease transmission for allografts. The objective of this study was to design a novel three-dimensional nanostructured bone substitute based on magnetically synthesized single-walled carbon nanotubes (SWCNT), biomimetic hydrothermally treated nanocrystalline hydroxyapatite, and a biocompatible hydrogel (chitosan). Both nanocrystalline hydroxyapatite and SWCNT have a biomimetic nanostructure, excellent osteoconductivity, and high potential to improve the load-bearing capacity of hydrogels. Methods Specifically, three-dimensional porous chitosan scaffolds with different concentrations of nanocrystalline hydroxyapatite and SWCNT were created to support the growth of human osteoblasts (bone-forming cells) using a lyophilization procedure. Two types of SWCNT were synthesized in an arc discharge with a magnetic field (B-SWCNT) and without a magnetic field (N-SWCNT) for improving bone regeneration. Results Nanocomposites containing magnetically synthesized B-SWCNT had superior cytocompatibility properties when compared with nonmagnetically synthesized N-SWCNT. B-SWCNT have much smaller diameters and are twice as long as their nonmagnetically prepared counterparts, indicating that the dimensions of carbon nanotubes can have a substantial effect on osteoblast attachment. Conclusion This study demonstrated that a chitosan nanocomposite with both B-SWCNT and 20% nanocrystalline hydroxyapatite could achieve a higher osteoblast density when compared with the other experimental groups, thus making this nanocomposite promising for further exploration for bone regeneration. PMID:22619545

Co-precipitation of tobramycin into biomimetically coated orthopedic fixation pins employing submicron-thin seed layers of hydroxyapatite.

PubMed

Sörensen, Jan H; Lilja, Mirjam; Åstrand, Maria; Sörensen, Torben C; Procter, Philip; Strømme, Maria; Steckel, Hartwig

2014-01-01

The migration, loosening and cut-out of implants and nosocomial infections are current problems associated with implant surgery. New innovative strategies to overcome these issues are emphasized in today's research. The current work presents a novel strategy involving co-precipitation of tobramycin with biomimetic hydroxyapatite (HA) formation to produce implant coatings that control local drug delivery to prevent early bacterial colonization of the implant. A submicron- thin HA layer served as seed layer for the co-precipitation process and allowed for incorporation of tobramycin in the coating from a stock solution of antibiotic concentrations as high as 20 mg/ml. Concentrations from 0.5 to 20 mg/ml tobramycin and process temperatures of 37 °C and 60 °C were tested to assess the optimal parameters for a thin tobramycin- delivering HA coating on discs and orthopedic fixation pins. The morphology and thickness of the coating and the drug-release profile were evaluated via scanning electron microscopy and high performance liquid chromatography. The coatings delivered pharmaceutically relevant amounts of tobramycin over a period of 12 days. To the best of our knowledge, this is the longest release period ever observed for a fast-loaded biomimetic implant coating. The presented approach could form the foundation for development of combination device/antibiotic delivery vehicles tailored to meet well-defined clinical needs while combating infections and ensuring fast implant in-growth.

Arterial specification of endothelial cells derived from human induced pluripotent stem cells in a biomimetic flow bioreactor.

PubMed

Sivarapatna, Amogh; Ghaedi, Mahboobe; Le, Andrew V; Mendez, Julio J; Qyang, Yibing; Niklason, Laura E

2015-01-01

Endothelial cells (ECs) exist in different microenvironments in vivo, including under different levels of shear stress in arteries versus veins. Standard stem cell differentiation protocols to derive ECs and EC-subtypes from human induced pluripotent stem cells (hiPSCs) generally use growth factors or other soluble factors in an effort to specify cell fate. In this study, a biomimetic flow bioreactor was used to subject hiPSC-derived ECs (hiPSC-ECs) to shear stress to determine the impacts on phenotype and upregulation of markers associated with an anti-thrombotic, anti-inflammatory, arterial-like phenotype. The in vitro bioreactor system was able to efficiently mature hiPSC-ECs into arterial-like cells in 24 h, as demonstrated by qRT-PCR for arterial markers EphrinB2, CXCR4, Conexin40 and Notch1, as well protein-level expression of Notch1 intracellular domain (NICD). Furthermore, the exogenous addition of soluble factors was not able to fully recapitulate this phenotype that was imparted by shear stress exposure. The induction of these phenotypic changes was biomechanically mediated in the shear stress bioreactor. This biomimetic flow bioreactor is an effective means for the differentiation of hiPSC-ECs toward an arterial-like phenotype, and is amenable to scale-up for culturing large quantities of cells for tissue engineering applications. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Biomimetic Propulsor for Active Noise Control. Part 2: Theory

NASA Astrophysics Data System (ADS)

Annaswamy Krol, A., Jr.; Bandyopadhyay, P. R.

2000-11-01

The alteration of radiated noise in underwater propulsors using biomimetic active control is considered. Wake momentum filling is carried out by introducing artificial muscles at the trailing edge of a stator blade of an upstream stator propulsor, and articulating them like a fish tail (see companion abstract Part 1). Using a systems framework, we derive a methodology for the articulation of the muscles with active control. The unsteady force produced on the rotor because of velocity perturbations due to actuator displacements, wake deficits caused by stator boundary layers, and blade rotation is modeled. Linear and adaptive nonlinear control strategies are described for articulating the tail using unsteady force measurements. This active control procedure can be viewed as the realization of “virtual” blades with different sweep and noise characteristics and can affect the noise spectrum due to direct radiation significantly. The work provides an understanding of the effect of nonuniform wakes on radiated noise and can lead to a general approach by which wakes can be altered.

Triangular prism-shaped β-peptoid helices as unique biomimetic scaffolds

NASA Astrophysics Data System (ADS)

Laursen, Jonas S.; Harris, Pernille; Fristrup, Peter; Olsen, Christian A.

2015-05-01

β-Peptoids are peptidomimetics based on N-alkylated β-aminopropionic acid residues (or N-alkyl-β-alanines). This type of peptide mimic has previously been incorporated in biologically active ligands and has been hypothesized to be able to exhibit foldamer properties. Here we show, for the first time, that β-peptoids can be tuned to fold into stable helical structures. We provide high-resolution X-ray crystal structures of homomeric β-peptoid hexamers, which reveal right-handed helical conformations with exactly three residues per turn and a helical pitch of 9.6-9.8 Å between turns. The presence of folded conformations in solution is supported by circular dichroism spectroscopy showing length- and solvent dependency, and molecular dynamics simulations provide further support for a stabilized helical secondary structure in organic solvent. We thus outline a framework for future design of novel biomimetics that display functional groups with high accuracy in three dimensions, which has potential for development of new functional materials.

Mechanics of tunable helices and geometric frustration in biomimetic seashells

NASA Astrophysics Data System (ADS)

Guo, Qiaohang; Chen, Zi; Li, Wei; Dai, Pinqiang; Ren, Kun; Lin, Junjie; Taber, Larry A.; Chen, Wenzhe

2014-03-01

Helical structures are ubiquitous in nature and engineering, ranging from DNA molecules to plant tendrils, from sea snail shells to nanoribbons. While the helical shapes in natural and engineered systems often exhibit nearly uniform radius and pitch, helical shell structures with changing radius and pitch, such as seashells and some plant tendrils, add to the variety of this family of aesthetic beauty. Here we develop a comprehensive theoretical framework for tunable helical morphologies, and report the first biomimetic seashell-like structure resulting from mechanics of geometric frustration. In previous studies, the total potential energy is everywhere minimized when the system achieves equilibrium. In this work, however, the local energy minimization cannot be realized because of the geometric incompatibility, and hence the whole system deforms into a shape with a global energy minimum whereby the energy in each segment may not necessarily be locally optimized. This novel approach can be applied to develop materials and devices of tunable geometries with a range of applications in nano/biotechnology.

Transport of Proteins Dissolved in Organic Solvents Across Biomimetic Membranes

NASA Astrophysics Data System (ADS)

Bromberg, Lev E.; Klibanov, Alexander M.

1995-02-01

Using lipid-impregnated porous cellulose membranes as biomimetic barriers, we tested the hypothesis that to afford effective transmembrane transfer of proteins and nucleic acids, the vehicle solvent should be able to dissolve both the biopolymers and the lipids. While the majority of solvents dissolve one or the other, ethanol and methanol were found to dissolve both, especially if the protein had been lyophilized from an aqueous solution of a pH remote from the protein's isoelectric point. A number of proteins, as well as RNA and DNA, dissolved in these alcohols readily crossed the lipidized membranes, whereas the same biopolymers placed in nondissolving solvents (e.g., hexane and ethyl acetate) or in those unable to dissolve lipids (e.g., water and dimethyl sulfoxide) exhibited little transmembrane transport. The solubility of biopolymers in ethanol and methanol was further enhanced by complexation with detergents and poly(ethylene glycol); significant protein and nucleic acid transport through the lipidized membranes was observed from these solvents but not from water.

Microwave-induced biomimetic approach for hydroxyapatite coatings of chitosan scaffolds.

PubMed

Kaynak Bayrak, Gökçe; Demirtaş, T Tolga; Gümüşderelioğlu, Menemşe

2017-02-10

Simulated body fluid (SBF) can form calcium phosphates on osteoinductive materials, so it is widely used for coating of bone scaffolds to mimic natural extracellular matrix (ECM). However, difficulties of bulk coating in 3D scaffolds and the necessity of long process times are the common problems for coating with SBF. In the present study, a microwave-assisted process was developed for rapid and internal coating of chitosan scaffolds. The scaffolds were fabricated as superporous hydrogel (SPH) by combining microwave irradiation and gas foaming methods. Then, they were immersed into 10x  SBF-like solution and homogenous bone-like hydroxyapatite (HA) coating was achieved by microwave treatment at 600W without the need of any nucleating agent. Cell culture studies with MC3T3-E1 preosteoblasts showed that microwave-assisted biomimetic HA coating process could be evaluated as an efficient and rapid method to obtain composite scaffolds for bone tissue engineering. Copyright © 2016 Elsevier Ltd. All rights reserved.

Enzymatically active biomimetic micropropellers for the penetration of mucin gels

PubMed Central

Walker, Debora; Käsdorf, Benjamin T.; Jeong, Hyeon-Ho; Lieleg, Oliver; Fischer, Peer

2015-01-01

In the body, mucus provides an important defense mechanism by limiting the penetration of pathogens. It is therefore also a major obstacle for the efficient delivery of particle-based drug carriers. The acidic stomach lining in particular is difficult to overcome because mucin glycoproteins form viscoelastic gels under acidic conditions. The bacterium Helicobacter pylori has developed a strategy to overcome the mucus barrier by producing the enzyme urease, which locally raises the pH and consequently liquefies the mucus. This allows the bacteria to swim through mucus and to reach the epithelial surface. We present an artificial system of reactive magnetic micropropellers that mimic this strategy to move through gastric mucin gels by making use of surface-immobilized urease. The results demonstrate the validity of this biomimetic approach to penetrate biological gels, and show that externally propelled microstructures can actively and reversibly manipulate the physical state of their surroundings, suggesting that such particles could potentially penetrate native mucus. PMID:26824056

MIPs and Aptamers for Recognition of Proteins in Biomimetic Sensing.

PubMed

Menger, Marcus; Yarman, Aysu; Erdőssy, Júlia; Yildiz, Huseyin Bekir; Gyurcsányi, Róbert E; Scheller, Frieder W

2016-07-18

Biomimetic binders and catalysts have been generated in order to substitute the biological pendants in separation techniques and bioanalysis. The two major approaches use either "evolution in the test tube" of nucleotides for the preparation of aptamers or total chemical synthesis for molecularly imprinted polymers (MIPs). The reproducible production of aptamers is a clear advantage, whilst the preparation of MIPs typically leads to a population of polymers with different binding sites. The realization of binding sites in the total bulk of the MIPs results in a higher binding capacity, however, on the expense of the accessibility and exchange rate. Furthermore, the readout of the bound analyte is easier for aptamers since the integration of signal generating labels is well established. On the other hand, the overall negative charge of the nucleotides makes aptamers prone to non-specific adsorption of positively charged constituents of the sample and the "biological" degradation of non-modified aptamers and ionic strength-dependent changes of conformation may be challenging in some application.

Erythrocyte membrane-camouflaged polymeric nanoparticles as a biomimetic delivery platform

PubMed Central

Hu, Che-Ming J.; Zhang, Li; Aryal, Santosh; Cheung, Connie; Fang, Ronnie H.; Zhang, Liangfang

2011-01-01

Efforts to extend nanoparticle residence time in vivo have inspired many strategies in particle surface modifications to bypass macrophage uptake and systemic clearance. Here we report a top-down biomimetic approach in particle functionalization by coating biodegradable polymeric nanoparticles with natural erythrocyte membranes, including both membrane lipids and associated membrane proteins for long-circulating cargo delivery. The structure, size and surface zeta potential, and protein contents of the erythrocyte membrane-coated nanoparticles were verified using transmission electron microscopy, dynamic light scattering, and gel electrophoresis, respectively. Mice injections with fluorophore-loaded nanoparticles revealed superior circulation half-life by the erythrocyte-mimicking nanoparticles as compared to control particles coated with the state-of-the-art synthetic stealth materials. Biodistribution study revealed significant particle retention in the blood 72 h following the particle injection. The translocation of natural cellular membranes, their associated proteins, and the corresponding functionalities to the surface of synthetic particles represents a unique approach in nanoparticle functionalization. PMID:21690347

Preparation of biomimetic nano-structured films with multi-scale roughness

NASA Astrophysics Data System (ADS)

Shelemin, A.; Nikitin, D.; Choukourov, A.; Kylián, O.; Kousal, J.; Khalakhan, I.; Melnichuk, I.; Slavínská, D.; Biederman, H.

2016-06-01

Biomimetic nano-structured films are valuable materials in various applications. In this study we introduce a fully vacuum-based approach for fabrication of such films. The method combines deposition of nanoparticles (NPs) by gas aggregation source and deposition of overcoat thin film that fixes the nanoparticles on a surface. This leads to the formation of nanorough surfaces which, depending on the chemical nature of the overcoat, may range from superhydrophilic to superhydrophobic. In addition, it is shown that by proper adjustment of the amount of NPs it is possible to tailor adhesive force on superhydrophobic surfaces. Finally, the possibility to produce NPs in a wide range of their size (45-240 nm in this study) makes it possible to produce surfaces not only with single scale roughness, but also with bi-modal or even multi-modal character. Such surfaces were found to be superhydrophobic with negligible water contact angle hysteresis and hence truly slippery.

Mineralization induction effects of osteopontin, bone sialoprotein, and dentin phosphoprotein on a biomimetic collagen substrate.

PubMed

Zurick, Kevin M; Qin, Chunlin; Bernards, Matthew T

2013-06-01

Native bone tissue is composed of a matrix of collagen, noncollagenous proteins, and calcium phosphate minerals, which are primarily hydroxyapatite. The SIBLING (small integrin-binding ligand, N-linked glycoprotein) family of proteins is the primary noncollagenous protein group found in mineralized tissues. In this work, the mineralization induction capabilities of three of the SIBLING members, bone sialoprotein (BSP), osteopontin (OPN), and the calcium-binding subdomain of dentin sialophosphoprotein, dentin phosphoprotein (DPP), are directly compared on a biomimetic collagen substrate. A self-assembled, loosely aligned collagen fibril substrate was prepared, and then (125) I-radiolabeled adsorption isotherms were developed for BSP, OPN, and DPP. The results showed that BSP exhibited the highest binding capacity for collagen at lower concentrations, followed by DPP and OPN. However, at the highest concentrations, all three proteins had similar adsorption levels. The adsorption isotherms were then used to identify conditions that resulted in identical amounts of adsorbed protein. These substrates were prepared and placed in simulated body fluid for 5, 10, and 24 h at 37°C. The resulting mineral morphology was assessed by atomic force microscopy, and the composition was determined using photochemical assays. Mineralization was seen in the presence of all the proteins. However, DPP was seen to be the only protein that formed individual mineral nodules similar to those seen in developing bone. This suggests that DPP plays a significant role in the biomineralization process and that the incorporation of DPP into tissue engineering constructs may facilitate the induction of biomimetic mineral formation. Copyright © 2012 Wiley Periodicals, Inc.

Mineralization Induction Effects of Osteopontin, Bone Sialoprotein, and Dentin Phosphoprotein on a Biomimetic Collagen Substrate

PubMed Central

Zurick, Kevin M.; Qin, Chunlin; Bernards, Matthew T.

2012-01-01

Native bone tissue is composed of a matrix of collagen, non-collagenous proteins, and calcium phosphate minerals, which are primarily hydroxyapatite (HA). The SIBLING (small integrin-binding ligand, N-linked glycoprotein) family of proteins is the primary non-collagenous protein group found in mineralized tissues. In this work, the mineralization induction capabilities of three of the SIBLING members, bone sialoprotein (BSP), osteopontin (OPN), and the calcium binding subdomain of dentin sialophosphoprotein, dentin phosphoprotein (DPP), are directly compared on a biomimetic collagen substrate. A self-assembled, loosely aligned collagen fibril substrate was prepared and then 125I radiolabeled adsorption isotherms were developed for BSP, OPN, and DPP. The results showed that BSP exhibited the highest binding capacity for collagen at lower concentrations, followed by DPP and OPN. However, at the highest concentrations all three proteins had similar adsorption levels. The adsorption isotherms were then used to identify conditions that resulted in identical amounts of adsorbed protein. These substrates were prepared and placed in simulated body fluid for 5 hours, 10 hours, and 24 hours at 37°C. The resulting mineral morphology was assessed by atomic force microscopy and the composition was determined using photochemical assays. Mineralization was seen in the presence of all of the proteins. However, DPP was seen to be the only protein that formed individual mineral nodules similar to those seen in developing bone. This suggests that DPP plays a significant role in the biomineralization process and that the incorporation of DPP into tissue engineering constructs may facilitate the induction of biomimetic mineral formation. PMID:23161527

A biomimetic colorimetric logic gate system based on multi-functional peptide-mediated gold nanoparticle assembly.

PubMed

Li, Yong; Li, Wang; He, Kai-Yu; Li, Pei; Huang, Yan; Nie, Zhou; Yao, Shou-Zhuo

2016-04-28

In natural biological systems, proteins exploit various functional peptide motifs to exert target response and activity switch, providing a functional and logic basis for complex cellular activities. Building biomimetic peptide-based bio-logic systems is highly intriguing but remains relatively unexplored due to limited logic recognition elements and complex signal outputs. In this proof-of-principle work, we attempted to address these problems by utilizing multi-functional peptide probes and the peptide-mediated nanoparticle assembly system. Here, the rationally designed peptide probes function as the dual-target responsive element specifically responsive to metal ions and enzymes as well as the mediator regulating the assembly of gold nanoparticles (AuNPs). Taking advantage of Zn2+ ions and chymotrypsin as the model inputs of metal ions and enzymes, respectively, we constructed the peptide logic system computed by the multi-functional peptide probes and outputted by the readable colour change of AuNPs. In this way, the representative binary basic logic gates (AND, OR, INHIBIT, NAND, IMPLICATION) have been achieved by delicately coding the peptide sequence, demonstrating the versatility of our logic system. Additionally, we demonstrated that the three-input combinational logic gate (INHIBIT-OR) could also be successfully integrated and applied as a multi-tasking biosensor for colorimetric detection of dual targets. This nanoparticle-based peptide logic system presents a valid strategy to illustrate peptide information processing and provides a practical platform for executing peptide computing or peptide-related multiplexing sensing, implying that the controllable nanomaterial assembly is a promising and potent methodology for the advancement of biomimetic bio-logic computation.

Osteoinductive peptide-functionalized nanofibers with highly ordered structure as biomimetic scaffolds for bone tissue engineering.

PubMed

Gao, Xiang; Zhang, Xiaohong; Song, Jinlin; Xu, Xiao; Xu, Anxiu; Wang, Mengke; Xie, Bingwu; Huang, Enyi; Deng, Feng; Wei, Shicheng

2015-01-01

The construction of functional biomimetic scaffolds that recapitulate the topographical and biochemical features of bone tissue extracellular matrix is now of topical interest in bone tissue engineering. In this study, a novel surface-functionalized electrospun polycaprolactone (PCL) nanofiber scaffold with highly ordered structure was developed to simulate the critical features of native bone tissue via a single step of catechol chemistry. Specially, under slightly alkaline aqueous solution, polydopamine (pDA) was coated on the surface of aligned PCL nanofibers after electrospinning, followed by covalent immobilization of bone morphogenetic protein-7-derived peptides onto the pDA-coated nanofiber surface. Contact angle measurement, Raman spectroscopy, and X-ray photoelectron spectroscopy confirmed the presence of pDA and peptides on PCL nanofiber surface. Our results demonstrated that surface modification with osteoinductive peptides could improve cytocompatibility of nanofibers in terms of cell adhesion, spreading, and proliferation. Most importantly, Alizarin Red S staining, quantitative real-time polymerase chain reaction, immunostaining, and Western blot revealed that human mesenchymal stem cells cultured on aligned nanofibers with osteoinductive peptides exhibited enhanced osteogenic differentiation potential than cells on randomly oriented nanofibers. Furthermore, the aligned nanofibers with osteoinductive peptides could direct osteogenic differentiation of human mesenchymal stem cells even in the absence of osteoinducting factors, suggesting superior osteogenic efficacy of biomimetic design that combines the advantages of osteoinductive peptide signal and highly ordered nanofibers on cell fate decision. The presented peptide-decorated bone-mimic nanofiber scaffolds hold a promising potential in the context of bone tissue engineering.

Refinement of the crystal structures of biomimetic weddellites produced by microscopic fungus Aspergillus niger

NASA Astrophysics Data System (ADS)

Rusakov, A. V.; Frank-Kamenetskaya, O. V.; Gurzhiy, V. V.; Zelenskaya, M. S.; Izatulina, A. R.; Sazanova, K. V.

2014-05-01

The single-crystal structures of four biomimetic weddellites CaC2O4 · (2 + x)H2O with different contents of zeolitic water ( x = 0.10-0.24 formula units) produced by the microscopic fungus Aspergillus niger were refined from X-ray diffraction data ( R = 0.029-0.038). The effect of zeolitic water content on the structural stability of weddellite was analyzed. The parameter a was shown to increase with increasing x due to the increase in the distance between water molecules along this direction. The water content and structural parameters of the synthesized weddellites are similar to those of weddellites from biofilms and kidney stones.

Biomimetic one-pot synthesis of gold nanoclusters/nanoparticles for targeted tumor cellular dual-modality imaging

NASA Astrophysics Data System (ADS)

Lin, Jing; Zhou, Zhijun; Li, Zhiming; Zhang, Chunlei; Wang, Xiansong; Wang, Kan; Gao, Guo; Huang, Peng; Cui, Daxiang

2013-04-01

Biomimetic synthesis has become a promising green pathway to prepare nanomaterials. In this study, bovine serum albumin (BSA)-conjugated gold nanoclusters/nanoparticles were successfully synthesized in water at room temperature by a protein-directed, solution-phase, green synthetic method. The synthesized BSA-Au nanocomplexes have fluorescence emission (588 nm) of gold nanoclusters and surface plasmon resonance of gold nanoparticles. The BSA-Au nanocomplexes display non-cytotoxicity and excellent biocompatibility on MGC803 gastric cancer cells. After conjugation of folic acid molecules, the obtained BSA-Au nanocomplexes showed highly selective targeting for MGC803 cells and dual-modality dark-field and fluorescence imaging.

Induction of a proton gradient across a gold-supported biomimetic membrane by electroenzymatic H2 oxidation.

PubMed

Gutiérrez-Sanz, Óscar; Tapia, Cristina; Marques, Marta C; Zacarias, Sonia; Vélez, Marisela; Pereira, Inês A C; De Lacey, Antonio L

2015-02-23

Energy-transduction mechanisms in living organisms, such as photosynthesis and respiration, store light and chemical energy in the form of an electrochemical gradient created across a lipid bilayer. Herein we show that the proton concentration at an electrode/phospholipid-bilayer interface can be controlled and monitored electrochemically by immobilizing a membrane-bound hydrogenase. Thus, the energy derived from the electroenzymatic oxidation of H2 can be used to generate a proton gradient across the supported biomimetic membrane. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomimetic growth of gallic acid-ZnO hybrid assemblies and their applications

NASA Astrophysics Data System (ADS)

Sarker, Nazmul H.; Barnaby, Stacey N.; Fath, Karl R.; Frayne, Stephen H.; Nakatsuka, Nako; Banerjee, Ipsita A.

2012-03-01

In this study, we probed the biomimetic formation of gallic acid (GA)-ZnO nanoparticle hybrids. It was found that the morphologies formed were dependent upon pH values, resulting in GA-ZnO hybrids of varying shapes such as micro or nanoplates or fibers. The formed supramolecular GA-ZnO hybrids were found to be luminescent as indicated by confocal microscopy and were utilized for the photocatalytic degradation of the organic dye methylene blue. We also explored the bactericidal effects of the hybrids on Staphylococcus aureus ( S. aureus) as well as Escherichia Coli ( E. Coli). Thus, we have developed a new class of shape-controlled nanohybrid assemblies via mild, green synthetic methods that may be utilized for photocatalytic degradation for environmental remediation as well as for antibacterial applications.

Biomimetic photo-actuation: progress and challenges

NASA Astrophysics Data System (ADS)

Dicker, Michael P. M.; Weaver, Paul M.; Rossiter, Jonathan M.; Bond, Ian P.; Faul, Charl F. J.

2016-04-01

Photo-actuation, such as that observed in the reversible sun-tracking movements of heliotropic plants, is produced by a complex, yet elegant series of processes. In the heliotropic leaf movements of the Cornish Mallow, photo-actuation involves the generation, transport and manipulation of chemical signals from a distributed network of sensors in the leaf veins to a specialized osmosis driven actuation region in the leaf stem. It is theorized that such an arrangement is both efficient in terms of materials use and operational energy conversion, as well as being highly robust. We concern ourselves with understanding and mimicking these light driven, chemically controlled actuating systems with the aim of generating intelligent structures which share the properties of efficiency and robustness that are so important to survival in Nature. In this work we present recent progress in mimicking these photo-actuating systems through remote light exposure of a metastable state photoacid and the resulting signal and energy transfer through solution to a pH-responsive hydrogel actuator. Reversible actuation strains of 20% were achieved from this arrangement, with modelling then employed to reveal the critical influence hydrogel pKa has on this result. Although the strong actuation achieved highlights the progress that has been made in replicating the principles of biomimetic photo-actuation, challenges such as photoacid degradation were also revealed. It is anticipated that current work can directly lead to the development of high-performance and low-cost solartrackers for increased photovoltaic energy capture and to the creation of new types of intelligent structures employing chemical control systems.

Making microenvironments: A look into incorporating macromolecular crowding into in vitro experiments, to generate biomimetic microenvironments which are capable of directing cell function for tissue engineering applications.

PubMed

Benny, Paula; Raghunath, Michael

2017-01-01

Biomimetic microenvironments are key components to successful cell culture and tissue engineering in vitro. One of the most accurate biomimetic microenvironments is that made by the cells themselves. Cell-made microenvironments are most similar to the in vivo state as they are cell-specific and produced by the actual cells which reside in that specific microenvironment. However, cell-made microenvironments have been challenging to re-create in vitro due to the lack of extracellular matrix composition, volume and complexity which are required. By applying macromolecular crowding to current cell culture protocols, cell-made microenvironments, or cell-derived matrices, can be generated at significant rates in vitro. In this review, we will examine the causes and effects of macromolecular crowding and how it has been applied in several in vitro systems including tissue engineering.

Biomimetics and the Development of Humanlike Robots as the Ultimate Challenge

NASA Technical Reports Server (NTRS)

Bar-Cohen, Yoseph

2011-01-01

Evolution led to effective solutions to nature's challenges and they were improved over millions of years. Humans have always made efforts to use nature as a model for innovation and problems solving. These efforts became more intensive in recent years where systematic studies of nature are being made towards better understanding and applying more sophisticated capabilities. Making humanlike robots, including the appearance, functions and intelligence, poses the ultimate challenges to biomimetics. For many years, making such robots was considered science fiction, but as a result of significant advances in biologically inspired technologies, such robots are increasingly becoming an engineering reality. There are already humanlike robots that walk, talk, interpret speech, make eye-contact and facial expressions, as well as perform many other humanlike functions. In this paper, the state-of-the-art of humanlike robots, potential applications and issues of concern will be reviewed.

Biomimetic mineralization of metal-organic frameworks as protective coatings for biomacromolecules

NASA Astrophysics Data System (ADS)

Liang, Kang; Ricco, Raffaele; Doherty, Cara M.; Styles, Mark J.; Bell, Stephen; Kirby, Nigel; Mudie, Stephen; Haylock, David; Hill, Anita J.; Doonan, Christian J.; Falcaro, Paolo

2015-06-01

Enhancing the robustness of functional biomacromolecules is a critical challenge in biotechnology, which if addressed would enhance their use in pharmaceuticals, chemical processing and biostorage. Here we report a novel method, inspired by natural biomineralization processes, which provides unprecedented protection of biomacromolecules by encapsulating them within a class of porous materials termed metal-organic frameworks. We show that proteins, enzymes and DNA rapidly induce the formation of protective metal-organic framework coatings under physiological conditions by concentrating the framework building blocks and facilitating crystallization around the biomacromolecules. The resulting biocomposite is stable under conditions that would normally decompose many biological macromolecules. For example, urease and horseradish peroxidase protected within a metal-organic framework shell are found to retain bioactivity after being treated at 80 °C and boiled in dimethylformamide (153 °C), respectively. This rapid, low-cost biomimetic mineralization process gives rise to new possibilities for the exploitation of biomacromolecules.

Energy-independent intracellular gene delivery mediated by polymeric biomimetics of cell-penetrating peptides.

PubMed

Chae, Su Young; Kim, Hyun June; Lee, Min Sang; Jang, Yeon Lim; Lee, Yuhan; Lee, Soo Hyeon; Lee, Kyuri; Kim, Sun Hwa; Kim, Hong Tae; Chi, Sang-Cheol; Park, Tae Gwan; Jeong, Ji Hoon

2011-09-09

Efficient gene transfer into mammalian cells mediated by small molecular amphiphile-polymer conjugates, bile acid-polyethylenimine (BA-PEI), is demonstrated, opening an efficient transport route for genetic materials across the cell membrane. This process occurs without the aid of endocytosis or other energy-consuming processes, thus mimicking macromolecular transduction by cell-penetrating peptides. The exposure of a hydrophilic face of the amphiphilic BA moiety on the surface of BA-PEI/DNA complex that mediates direct contact of the BA molecules to the cell surface seems to play an important role in the endocytosis- and energy-independent internalization process. The new modality of the polymeric biomimetics can be applied to enhanced delivery of macromolecular therapeutics. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomimetic Beetle-Inspired Flapping Air Vehicle Actuated by Ionic Polymer-Metal Composite Actuator

PubMed Central

Zhao, Yang; Xu, Di; Sheng, Jiazheng; Meng, Qinglong; Wu, Dezhi; Wang, Lingyun; Xiao, Jingjing; Lv, Wenlong; Sun, Daoheng

2018-01-01

During the last decades, the ionic polymer-metal composite (IPMC) received much attention because of its potential capabilities, such as large displacement and flexible bending actuation. In this paper, a biomimetic flapping air vehicle was proposed by combining the superiority of ionic polymer metal composite with the bionic beetle flapping principle. The blocking force was compared between casted IPMC and IPMC. The flapping state of the wing was investigated and the maximum displacement and flapping angle were measured. The flapping displacement under different voltage and frequency was tested. The flapping displacement of the wing and the support reaction force were measured under different frequency by experiments. The experimental results indicate that the high voltage and low frequency would get large flapping displacement. PMID:29682006

Biomimetic Beetle-Inspired Flapping Air Vehicle Actuated by Ionic Polymer-Metal Composite Actuator.

PubMed

Zhao, Yang; Xu, Di; Sheng, Jiazheng; Meng, Qinglong; Wu, Dezhi; Wang, Lingyun; Xiao, Jingjing; Lv, Wenlong; Chen, Qinnan; Sun, Daoheng

2018-01-01

During the last decades, the ionic polymer-metal composite (IPMC) received much attention because of its potential capabilities, such as large displacement and flexible bending actuation. In this paper, a biomimetic flapping air vehicle was proposed by combining the superiority of ionic polymer metal composite with the bionic beetle flapping principle. The blocking force was compared between casted IPMC and IPMC. The flapping state of the wing was investigated and the maximum displacement and flapping angle were measured. The flapping displacement under different voltage and frequency was tested. The flapping displacement of the wing and the support reaction force were measured under different frequency by experiments. The experimental results indicate that the high voltage and low frequency would get large flapping displacement.

Synthesis and Characterization of a Chondroitin Sulfate Based Hybrid Bio/Synthetic Biomimetic Aggrecan Macromolecule

NASA Astrophysics Data System (ADS)

Sarkar, Sumona

Lower back pain resulting from intervertebral disc degeneration is one of the leading musculoskeletal disorders confronting our health system. In order to mechanically stabilize the disc early in the degenerative cascade and prevent the need for spinal fusion surgeries, we have proposed the development of a hybrid-bio/synthetic biomimetic proteoglycan macromolecule for injection into the disc in the early stages of degeneration. The goal of this thesis was to incorporate natural chondroitin sulfate (CS) chains into bottle brush polymer synthesis strategies for the fabrication of CS-macromolecules which mimic the proteoglycan structure and function while resisting enzymatic degradation. Both the "grafting-to" and "grafting-through" techniques of bottle brush synthesis were explored. CS was immobilized via a terminal primary amine onto a model polymeric backbone (polyacrylic acid) for investigation of the "grafting-to" strategy and an epoxy-amine step-growth polymerization technique was utilized for the "grafting-through" synthesis of CS-macromolecules with polyethylene glycol backbone segments. Incorporation of a synthetic polymeric backbone at the terminal amine of CS was confirmed via biochemical assays, 1H-NMR and FTIR spectroscopy, and CS-macromolecule size was demonstrated to be higher than that of natural CS via gel permeation chromatography, transmission electron microscopy and viscosity measurements. Further analysis of CS-macromolecule functionality indicated maintenance of natural CS properties such as high fixed charge density, high osmotic potential and low cytotoxicity with nucleus pulposus cells. These studies are the first attempt at the incorporation of natural CS into biomimetic bottle brush structures. CS-macromolecules synthesized via the methods developed in these studies may be utilized in the treatment and prevention of debilitating back pain as well as act as mimetics for other proteoglycans implicated in cartilage, heart valve, and nervous

Adsorption of nucleotides on biomimetic apatite: The case of adenosine 5⿲ triphosphate (ATP)

NASA Astrophysics Data System (ADS)

Hammami, Khaled; El-Feki, Hafed; Marsan, Olivier; Drouet, Christophe

2016-01-01

ATP is a well-known energy supplier in cells. The idea to associate ATP to pharmaceutical formulations/biotechnological devices to promote cells activity by potentially modulating their microenvironment thus appears as an appealing novel approach. Since biomimetic nanocrystalline apatites have shown great promise for biomedical applications (bone regeneration, cells diagnostics/therapeutics, ⿦), thanks to a high surface reactivity and an intrinsically high biocompatibility, the present contribution was aimed at exploring ATP/apatite interactions. ATP adsorption on a synthetic carbonated nanocrystalline apatite preliminarily characterized (by XRD, FTIR, Raman, TG-DTA and SEM-EDX) was investigated in detail, pointing out a good agreement with Sips isothermal features. Adsorption characteristics were compared to those previously obtained on monophosphate nucleotides (AMP, CMP), unveiling some specificities. ATP was found to adsorb effectively onto biomimetic apatite: despite smaller values of the affinity constant KS and the exponential factor m, larger adsorbed amounts were reached for ATP as compared to AMP for any given concentration in solution. m < 1 suggests that the ATP/apatite adsorption process is mostly guided by direct surface bonding rather than through stabilizing intermolecular interactions. Although standard οGads ° was estimated to only ⿿4 kJ/mol, the large value of Nmax led to significantly negative effective οGads values down to ⿿33 kJ/mol, reflecting the spontaneous character of adsorption process. Vibrational spectroscopy data (FTIR and Raman) pointed out spectral modifications upon adsorption, confirming chemical-like interactions where both the triphosphate group of ATP and its nucleic base were involved. The present study is intended to serve as a basis for future research works involving ATP and apatite nanocrystals/nanoparticles in view of biomedical applications (e.g. bone tissue engineering, intracellular drug delivery, ⿦).

Bioactive gyroid scaffolds formed by sacrificial templating of nanocellulose and nanochitin hydrogels as instructive platforms for biomimetic tissue engineering.

PubMed

Torres-Rendon, Jose Guillermo; Femmer, Tim; De Laporte, Laura; Tigges, Thomas; Rahimi, Khosrow; Gremse, Felix; Zafarnia, Sara; Lederle, Wiltrud; Ifuku, Shinsuke; Wessling, Matthias; Hardy, John G; Walther, Andreas

2015-05-20

A sacrificial templating process using lithographically printed minimal surface structures allows complex de novo geo-metries of delicate hydrogel materials. The hydrogel scaffolds based on cellulose and chitin nanofibrils show differences in terms of attachment of human mesenchymal stem cells, and allow their differentiation into osteogenic outcomes. The approach here serves as a first example toward designer hydrogel scaffolds viable for biomimetic tissue engineering. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Biomimetic Delivery of Keratinocyte Growth Factor upon Cellular Demand for Accelerated Wound Healing in Vitro and in Vivo

PubMed Central

Geer, David J.; Swartz, Daniel D.; Andreadis, Stelios T.

2005-01-01

Exogenous keratinocyte growth factor (KGF) significantly enhances wound healing, but its use is hampered by a short biological half-life and lack of tissue selectivity. We used a biomimetic approach to achieve cell-controlled delivery of KGF by covalently attaching a fluorescent matrix-binding peptide that contained two domains: one recognized by factor XIII and the other by plasmin. Modified KGF was incorporated into the fibrin matrix at high concentration in a factor XIII-dependent manner. Cell-mediated activation of plasminogen to plasmin degraded the fibrin matrix and cleaved the peptides, releasing active KGF to the local microenvironment and enhancing epithelial cell proliferation and migration. To demonstrate in vivo effectiveness, we used a hybrid model of wound healing that involved transplanting human bioengineered skin onto athymic mice. At 6 weeks after grafting, the transplanted tissues underwent full thickness wounding and treatment with fibrin gels containing bound KGF. In contrast to topical KGF, fibrin-bound KGF persisted in the wounds for several days and was released gradually, resulting in significantly enhanced wound closure. A fibrinolytic inhibitor prevented this healing, indicating the requirement for cell-mediated fibrin degradation to release KGF. In conclusion, this biomimetic approach of localized, cell-controlled delivery of growth factors may accelerate healing of large full-thickness wounds and chronic wounds that are notoriously difficult to heal. PMID:16314471

Isotropic Versus Bipolar Functionalized Biomimetic Artificial Basement Membranes and Their Evaluation in Long-Term Human Cell Co-Culture.

PubMed

Rossi, Angela; Wistlich, Laura; Heffels, Karl-Heinz; Walles, Heike; Groll, Jürgen

2016-08-01

In addition to dividing tissues into compartments, basement membranes are crucial as cell substrates and to regulate cellular behavior. The development of artificial basement membranes is indispensable for the ultimate formation of functional engineered tissues; however, pose a challenge due to their complex structure. Herein, biodegradable electrospun polyester meshes are presented, exhibiting isotropic or bipolar bioactivation as a biomimetic and biofunctional model of the natural basement membrane. In a one-step preparation process, reactive star-shaped prepolymer additives, which generate a hydrophilic fiber surface, are electrospun with cell-adhesion-mediating peptides, derived from major components of the basement membrane. Human skin cells adhere to the functionalized meshes, and long-term co-culture experiments confirm that the artificial basement membranes recapitulate and preserve tissue specific functions. Several layers of immortalized human keratinocytes grow on the membranes, differentiating toward the surface and expressing typical epithelial markers. Fibroblasts migrate into the reticular lamina mimicking part of the mesh. Both cells types begin to produce extracellular matrix proteins and to remodel the initial membrane. It is shown at the example of skin that the artificial basement membrane design provokes biomimetic responses of different cell types and can thus be used as basis for the future development of basement membrane containing tissues. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sectioning studies of biomimetic collagen-hydroxyapatite coatings on Ti-6Al-4V substrates using focused ion beam

NASA Astrophysics Data System (ADS)

Hu, Changmin; Yu, Le; Wei, Mei

2018-06-01

A biomimetic bone-like collagen-hydroxyapatite (Col-HA) composite coating was formed on a surface-treated Ti-6Al-4V alloy substrate via simultaneous collagen self-assembly and hydroxyapatite nucleation. The coating process has been carried out by immersing sand-blasted, acid-etched and UV irradiated Ti-6Al-4V alloy in type I collagen-containing modified simulated body fluid (m-SBF). The surface morphology and phase composition of the coating were characterized using various techniques. More importantly, dual-beam FIB/SEMs with either gallium ion source (GFIB) or xenon plasma ion source (PFIB) were used to investigate the cross-sectional features of the biomimetic Col-HA composite coating in great details. As a result, the cross-sectional images and thin transmission electron microscopy (TEM) specimens were successfully obtained from the composite coating with no obvious damages or milling ion implantations. Both the cross-sectional SEM and TEM results have confirmed that the Col-HA coating demonstrates a similar microstructure to that of pure HA coating with homogeneously distributed elements across the whole cross section. Both coatings consist of a uniform, crack-free gradient structure with a dense layer adjacent to the interface between the Ti-6Al-4V substrate and the coating facilitating a strong bonding, while a porous structure at the coating surface aiding cell attachment.

Progress on CD-DVD laser microfabrication method to develop cell culture scaffolds integrating biomimetic characteristics

NASA Astrophysics Data System (ADS)

Hautefeuille, Mathieu; Vázquez-Victorio, Genaro; Cruz-Ramírez, Aaron; Cabriales, Lucia; Jiménez-Diaz, Edgar; Escutia-Guadarrama, Lidia; López-Aparicio, Jehú; Pérez-Calixto, Daniel; Cano-Jorge, Mariel; Nieto-Rivera, Brenda; Sánchez-Olvera, Raúl

2018-02-01

The development of organ-on-chip and biological scaffolds is currently requiring simpler methods to microstructure biocompatible materials in three dimensions, fabricate structural and functional elements in biomaterials or modify the physicochemical properties of desired substrates. With the aim of creating simple, cost-effective alternatives to conventional existing techniques to produce such platforms with very specific properties, a low-power CD-DVD laser pickup head was recycled and mounted on a programmable three-axis micro-displacement system in order to modify the surface of polymeric materials in a local fashion. Thanks to a specially-designed method using a strongly absorbing additive coating the materials of interest, it has been possible to establish and precisely control processes useful in microtechnology for biomedical applications and normally restricted to much less affordable high-power lasers. In this work, we present our latest progress regarding the application of our fabrication technique to the development of organ-on-chip platforms thanks to the simple integration of several biomimetic characteristics typically achieved with traditional, less cost-effective microtechnology methods in one step or through replica-molding. Our straightforward approach indeed enables great control of local laser microablation for true on-demand biomimetic micropatterned designs in several transparent polymers and hydrogels of tunable stiffness and is allowing integration of microfluidics, microelectronics, optical waveguides, surface microstructuring and even transfer of superficial protein micropatterns on a variety of biocompatible materials. The results presented here were validated using hepatic and fibroblasts cell lines to demonstrate the viability of our procedure for organ-on-chip development and show the impact of such features in cell culture.

Surface controlled biomimetic coating of polycaprolactone nanofiber meshes to be used as bone extracellular matrix analogues.

PubMed

Araujo, J V; Martins, A; Leonor, I B; Pinho, E D; Reis, R L; Neves, N M

2008-01-01

The aim of this work was to develop novel electrospun nanofiber meshes coated with a biomimetic calcium phosphate (BCP) layer that mimics the extracellular microenvironment found in the human bone structure. Poly (epsilon-caprolactone) (PCL) was selected because of its well-known medical applications, its biodegradability, biocompatibility and its susceptibility to partial hydrolysis by a straightforward alkaline treatment. The deposition of a calcium phosphate layer, similar to the inorganic phase of bone, on PCL nanofiber meshes was achieved by means of a surface modification. This initial surface modification was followed by treatment with solutions containing calcium and phosphate ions. The process was finished by a posterior immersion in a simulated body fluid (SBF) with nearly 1.5 x the inorganic concentration of the human blood plasma ions. After some optimization work, the best conditions were chosen to perform the biological assays. The influence of the bone-like BCP layer on the viability and adhesion, as well as on the proliferation of human osteoblast-like cells, was assessed. It was shown that PCL nanofiber meshes coated with a BCP layer support and enhance the proliferation of osteoblasts for long culture periods. The attractive properties of the coated structures produced in the present work demonstrated that those materials have potential to be used for applications in bone tissue engineering. This is the first time that nanofiber meshes could be coated with a biomimetic bone-like calcium phosphate layer produced in a way that the original mesh architecture can be fully maintained.

Insights on synergy of materials and structures in biomimetic platelet-matrix composites

NASA Astrophysics Data System (ADS)

Sakhavand, Navid; Shahsavari, Rouzbeh

2018-01-01

Hybrid materials such as biomimetic platelet-matrix composites are in high demand to confer low weight and multifunctional mechanical properties. This letter reports interfacial-bond regulated assembly of polymers on cement-an archetype model with significant infrastructure applications. We demonstrate a series of 20+ molecular dynamics studies on decoding and optimizing the complex interfacial interactions including the role and types of various heterogeneous, competing interfacial bonds that are key to adhesion and interfacial strength. Our results show an existence of an optimum overlap length scale (˜15 nm) between polymers and cement crystals, exhibiting the best balance of strength, toughness, stiffness, and ductility for the composite. This finding, combined with the fundamental insights into the nature of interfacial bonds, provides key hypotheses for selection and processing of constituents to deliberate the best synergy in the structure and materials of platelet-matrix composites.

Heterogeneous biomimetic catalysis using iron porphyrin for cyclohexane oxidation promoted by chitosan

NASA Astrophysics Data System (ADS)

Huang, Guan; Liu, Yao; Cai, Jing Li; Chen, Xiang Feng; Zhao, Shu Kai; Guo, Yong An; Wei, Su Juan; Li, Xu

2017-04-01

This study investigates how ligands modulate metalloporphyrin activity with the goal of producing a practical biomimetic catalyst for use in the chemical industry. We immobilized iron porphyrinate [iron-tetrakis-(4-sulfonatophenyl)-porphyrin; Fe(III) (TPPS)] on powdered chitosan (pd-CTS) to form an immobilized catalyst Fe(III) (TPPS)/pd-CTS, which was characterized using modern spectroscopic techniques and used for catalytic oxidation of cyclohexane with O2. Amino coordination to iron porphyrin in Fe(III) (TPPS)/pd-CTS altered the electron cloud density around the iron cation, probably by reducing the activation energy of Fe(III) (TPPS) and raising the reactivity of the iron ion catalytic center, thereby improving the catalytic efficiency. One milligram of Fe(III) (TPPS) catalyst can be reused three times for the oxidation reaction to yield an average of 22.9 mol% of cyclohexanone and cyclohexanol.

Piezoelectric Templates - New Views on Biomineralization and Biomimetics.

PubMed

Stitz, Nina; Eiben, Sabine; Atanasova, Petia; Domingo, Neus; Leineweber, Andreas; Burghard, Zaklina; Bill, Joachim

2016-05-23

Biomineralization in general is based on electrostatic interactions and molecular recognition of organic and inorganic phases. These principles of biomineralization have also been utilized and transferred to bio-inspired synthesis of functional materials during the past decades. Proteins involved in both, biomineralization and bio-inspired processes, are often piezoelectric due to their dipolar character hinting to the impact of a template's piezoelectricity on mineralization processes. However, the piezoelectric contribution on the mineralization process and especially the interaction of organic and inorganic phases is hardly considered so far. We herein report the successful use of the intrinsic piezoelectric properties of tobacco mosaic virus (TMV) to synthesize piezoelectric ZnO. Such films show a two-fold increase of the piezoelectric coefficient up to 7.2 pm V(-1) compared to films synthesized on non-piezoelectric templates. By utilizing the intrinsic piezoelectricity of a biotemplate, we thus established a novel synthesis pathway towards functional materials, which sheds light on the whole field of biomimetics. The obtained results are of even broader and general interest since they are providing a new, more comprehensive insight into the mechanisms involved into biomineralization in living nature.

Piezoelectric Templates - New Views on Biomineralization and Biomimetics

NASA Astrophysics Data System (ADS)

Stitz, Nina; Eiben, Sabine; Atanasova, Petia; Domingo, Neus; Leineweber, Andreas; Burghard, Zaklina; Bill, Joachim

2016-05-01

Biomineralization in general is based on electrostatic interactions and molecular recognition of organic and inorganic phases. These principles of biomineralization have also been utilized and transferred to bio-inspired synthesis of functional materials during the past decades. Proteins involved in both, biomineralization and bio-inspired processes, are often piezoelectric due to their dipolar character hinting to the impact of a template’s piezoelectricity on mineralization processes. However, the piezoelectric contribution on the mineralization process and especially the interaction of organic and inorganic phases is hardly considered so far. We herein report the successful use of the intrinsic piezoelectric properties of tobacco mosaic virus (TMV) to synthesize piezoelectric ZnO. Such films show a two-fold increase of the piezoelectric coefficient up to 7.2 pm V-1 compared to films synthesized on non-piezoelectric templates. By utilizing the intrinsic piezoelectricity of a biotemplate, we thus established a novel synthesis pathway towards functional materials, which sheds light on the whole field of biomimetics. The obtained results are of even broader and general interest since they are providing a new, more comprehensive insight into the mechanisms involved into biomineralization in living nature.

Additive Manufacturing of Biomedical Constructs with Biomimetic Structural Organizations

PubMed Central

Li, Xiao; He, Jiankang; Zhang, Weijie; Jiang, Nan; Li, Dichen

2016-01-01

Additive manufacturing (AM), sometimes called three-dimensional (3D) printing, has attracted a lot of research interest and is presenting unprecedented opportunities in biomedical fields, because this technology enables the fabrication of biomedical constructs with great freedom and in high precision. An important strategy in AM of biomedical constructs is to mimic the structural organizations of natural biological organisms. This can be done by directly depositing cells and biomaterials, depositing biomaterial structures before seeding cells, or fabricating molds before casting biomaterials and cells. This review organizes the research advances of AM-based biomimetic biomedical constructs into three major directions: 3D constructs that mimic tubular and branched networks of vasculatures; 3D constructs that contains gradient interfaces between different tissues; and 3D constructs that have different cells positioned to create multicellular systems. Other recent advances are also highlighted, regarding the applications of AM for organs-on-chips, AM-based micro/nanostructures, and functional nanomaterials. Under this theme, multiple aspects of AM including imaging/characterization, material selection, design, and printing techniques are discussed. The outlook at the end of this review points out several possible research directions for the future. PMID:28774030

Additive Manufacturing of Biomedical Constructs with Biomimetic Structural Organizations.

PubMed

Li, Xiao; He, Jiankang; Zhang, Weijie; Jiang, Nan; Li, Dichen

2016-11-09

Additive manufacturing (AM), sometimes called three-dimensional (3D) printing, has attracted a lot of research interest and is presenting unprecedented opportunities in biomedical fields, because this technology enables the fabrication of biomedical constructs with great freedom and in high precision. An important strategy in AM of biomedical constructs is to mimic the structural organizations of natural biological organisms. This can be done by directly depositing cells and biomaterials, depositing biomaterial structures before seeding cells, or fabricating molds before casting biomaterials and cells. This review organizes the research advances of AM-based biomimetic biomedical constructs into three major directions: 3D constructs that mimic tubular and branched networks of vasculatures; 3D constructs that contains gradient interfaces between different tissues; and 3D constructs that have different cells positioned to create multicellular systems. Other recent advances are also highlighted, regarding the applications of AM for organs-on-chips, AM-based micro/nanostructures, and functional nanomaterials. Under this theme, multiple aspects of AM including imaging/characterization, material selection, design, and printing techniques are discussed. The outlook at the end of this review points out several possible research directions for the future.

Fabrication of biomimetic dry-adhesion structures through nanosphere lithography

NASA Astrophysics Data System (ADS)

Kuo, P. C.; Chang, N. W.; Suen, Y.; Yang, S. Y.

2018-03-01

Components with surface nanostructures suitable for biomimetic dry adhesion have a great potential in applications such as gecko tape, climbing robots, and skin patches. In this study, a nanosphere lithography technique with self-assembly nanospheres was developed to achieve effective and efficient fabrication of dry-adhesion structures. Self-assembled monolayer nanospheres with high regularity were obtained through tilted dip-coating. Reactive-ion etching of the self-assembled nanospheres was used to fabricate nanostructures of different shapes and aspect ratios by varying the etching time. Thereafter, nickel molds with inverse nanostructures were replicated using the electroforming process. Polydimethylsiloxane (PDMS) nanostructures were fabricated through a gas-assisted hot-embossing method. The pulling test was performed to measure the shear adhesion on the glass substrate of a sample, and the static contact angle was measured to verify the hydrophobic property of the structure. The enhancement of the structure indicates that the adhesion force increased from 1.2 to 4.05 N/cm2 and the contact angle increased from 118.6° to 135.2°. This columnar structure can effectively enhance the adhesion ability of PDMS, demonstrating the potential of using nanosphere lithography for the fabrication of adhesive structures.

Directed Fluid Transport and Mixing with Biomimetic Cilia Arrays

NASA Astrophysics Data System (ADS)

Shields, A. R.; Evans, B. A.; Carstens, B. L.; Falvo, M. R.; Washburn, S.; Superfine, R.

2009-03-01

We present results on the long-range, directed fluid transport and fluidic mixing produced by the collective beating of arrays of biomimetic cilia. These artificial cilia are arrays of free-standing nanorods roughly the size of biological cilia, which we fabricate from a polymer-magnetic nanoparticle composite material and actuate with permanent magnets to mimic biological cilia. Biological cilia have evolved to produce microscale fluid transport and are increasingly being recognized as critical components in a wide range of biological systems. However, despite much effort cilia generated fluid flows remain an area of active study. In the last decade, cilia-driven fluid flow in the embryonic node of vertebrates has been implicated as the initial left-right symmetry breaking event in these embryos. With silia we generate directional fluid transport by mimicking the tilted conical beating of these nodal cilia. By seeding fluorescent microparticles into the fluid we have noted the existence of two distinct flow regimes. The fluid flow is directional and coherent above the cilia tips, while between the cilia tips and the floor particle motion is complicated and suggestive of chaotic advection.

Biomimetic Hydrogel Composites for Soil Stabilization and Contaminant Mitigation.

PubMed

Zhao, Zhi; Hamdan, Nasser; Shen, Li; Nan, Hanqing; Almajed, Abdullah; Kavazanjian, Edward; He, Ximin

2016-11-15

We have developed a novel method to synthesize a hyper-branched biomimetic hydrogel network across a soil matrix to improve the mechanical strength of the loose soil and simultaneously mitigate potential contamination due to excessive ammonium. This method successfully yielded a hierarchical structure that possesses the water retention, ion absorption, and soil aggregation capabilities of plant root systems in a chemically controllable manner. Inspired by the robust organic-inorganic composites found in many living organisms, we have combined this hydrogel network with a calcite biomineralization process to stabilize soil. Our experiments demonstrate that poly(acrylic acid) (PAA) can work synergistically with enzyme-induced carbonate precipitation (EICP) to render a versatile, high-performance soil stabilization method. PAA-enhanced EICP provides multiple benefits including lengthening of water supply time, localization of cementation reactions, reduction of harmful byproduct ammonium, and achievement of ultrahigh soil strength. Soil crusts we have obtained can sustain up to 4.8 × 10 3 kPa pressure, a level comparable to cementitious materials. An ammonium removal rate of 96% has also been achieved. These results demonstrate the potential for hydrogel-assisted EICP to provide effective soil improvement and ammonium mitigation for wind erosion control and other applications.

Biomimetic 3D tissue printing for soft tissue regeneration.

PubMed

Pati, Falguni; Ha, Dong-Heon; Jang, Jinah; Han, Hyun Ho; Rhie, Jong-Won; Cho, Dong-Woo

2015-09-01

Engineered adipose tissue constructs that are capable of reconstructing soft tissue with adequate volume would be worthwhile in plastic and reconstructive surgery. Tissue printing offers the possibility of fabricating anatomically relevant tissue constructs by delivering suitable matrix materials and living cells. Here, we devise a biomimetic approach for printing adipose tissue constructs employing decellularized adipose tissue (DAT) matrix bioink encapsulating human adipose tissue-derived mesenchymal stem cells (hASCs). We designed and printed precisely-defined and flexible dome-shaped structures with engineered porosity using DAT bioink that facilitated high cell viability over 2 weeks and induced expression of standard adipogenic genes without any supplemented adipogenic factors. The printed DAT constructs expressed adipogenic genes more intensely than did non-printed DAT gel. To evaluate the efficacy of our printed tissue constructs for adipose tissue regeneration, we implanted them subcutaneously in mice. The constructs did not induce chronic inflammation or cytotoxicity postimplantation, but supported positive tissue infiltration, constructive tissue remodeling, and adipose tissue formation. This study demonstrates that direct printing of spatially on-demand customized tissue analogs is a promising approach to soft tissue regeneration. Copyright © 2015 Elsevier Ltd. All rights reserved.

A synthetic leaf: the biomimetic potential of graphene oxide

NASA Astrophysics Data System (ADS)

Lamb, Marilla; Koch, George W.; Morgan, Eric R.; Shafer, Michael W.

2015-03-01

Emerging materials such as graphene oxide (GO) have micro and nano features that are functionally similar to those in plant cell walls involved in water transport. Therefore, it may now be possible to design and build biomimetic trees to lift water via mechanisms similar to those employed by trees, allowing for potential applications such as passive water pumping, filtering, and evaporative cooling. The tallest trees can raise large volumes of water to over 100 meters using only the vapor pressure gradient between their leaves and the atmosphere. This phenomenon occurs in all terrestrial plants when capillary forces generated in the microscopic pores in the cell walls of leaves are collectively applied to large diameter xylem conduits. The design of a synthetic tree that mimics these mechanisms will allow water to be moved to heights greater than is currently possible by any engineered system that does not require the use of a positive pressure pump. We are testing the suitability of membranous GO as the leaf of a synthetic tree and present an analysis in support of this design. In addition, we include results from a preliminary design using ceramics.

Development of a shape memory alloy actuated biomimetic vehicle

NASA Astrophysics Data System (ADS)

Garner, L. J.; Wilson, L. N.; Lagoudas, D. C.; Rediniotis, O. K.

2000-10-01

The development of a biomimetic active hydrofoil that utilizes shape memory alloy (SMA) actuator technology is presented. This work is the first stage prototype of a vehicle that will consist of many actuated body segments. The current work describes the design, modeling and testing of a single-segment demonstration SMA actuated hydrofoil. The SMA actuation elements are two sets of thin wires on either side of an elastomeric component that joins together the leading and trailing edges of the hydrofoil. Controlled heating and cooling of the two wire sets generates bi-directional bending of the elastomer, which in turn deflects the trailing edge of the hydrofoil. In this paper the design of the hydrofoil and the experimental tests preformed thereon are explained. A detailed account of SMA actuator preparation (training) and material characterization is given. Finite-element method (FEM) modeling of hydrofoil response to electrical heating of the SMA actuators is carried out using a thermomechanical constitutive model for the SMA with input from the material characterization. The modeling predictions are finally compared with experimental measurements of the trailing edge deflection and the SMA actuator temperature.

A Closer Look at Schlemm's Canal Cell Physiology: Implications for Biomimetics.

PubMed

Dautriche, Cula N; Tian, Yangzi; Xie, Yubing; Sharfstein, Susan T

2015-09-21

Among ocular pathologies, glaucoma is the second leading cause of progressive vision loss, expected to affect 80 million people worldwide by 2020. A primary cause of glaucoma appears to be damage to the conventional outflow tract. Conventional outflow tissues, a composite of the trabecular meshwork and the Schlemm's canal, regulate and maintain homeostatic responses to intraocular pressure. In glaucoma, filtration of aqueous humor into the Schlemm's canal is hindered, leading to an increase in intraocular pressure and subsequent damage to the optic nerve, with progressive vision loss. The Schlemm's canal encompasses a unique endothelium. Recent advances in culturing and manipulating Schlemm's canal cells have elucidated several aspects of their physiology, including ultrastructure, cell-specific marker expression, and biomechanical properties. This review highlights these advances and discusses implications for engineering a 3D, biomimetic, in vitro model of the Schlemm's canal endothelium to further advance glaucoma research, including drug testing and gene therapy screening.

Image Classification Using Biomimetic Pattern Recognition with Convolutional Neural Networks Features

PubMed Central

Huo, Guanying

2017-01-01

As a typical deep-learning model, Convolutional Neural Networks (CNNs) can be exploited to automatically extract features from images using the hierarchical structure inspired by mammalian visual system. For image classification tasks, traditional CNN models employ the softmax function for classification. However, owing to the limited capacity of the softmax function, there are some shortcomings of traditional CNN models in image classification. To deal with this problem, a new method combining Biomimetic Pattern Recognition (BPR) with CNNs is proposed for image classification. BPR performs class recognition by a union of geometrical cover sets in a high-dimensional feature space and therefore can overcome some disadvantages of traditional pattern recognition. The proposed method is evaluated on three famous image classification benchmarks, that is, MNIST, AR, and CIFAR-10. The classification accuracies of the proposed method for the three datasets are 99.01%, 98.40%, and 87.11%, respectively, which are much higher in comparison with the other four methods in most cases. PMID:28316614

Chondroitin sulfate template-mediated biomimetic synthesis of nano-flake hydroxyapatite

NASA Astrophysics Data System (ADS)

He, Dan; Xiao, Xiufeng; Liu, Fang; Liu, Rongfang

2008-11-01

By Ca(NO 3) 2·4H 2O and (NH 4) 3PO 4·3H 2O as reagents and chondroitin sulfate (ChS) as a template, nano-flake hydroxyapatite (HA) is synthesized using a biomimetic method according to the biomineralization theory. HA crystals obtained are characterized in crystalline phase, microstructure, chemical composition and morphology by X-ray diffraction (XRD), Fourier transform infrared spectroscope (FTIR), transmission electron microscopy (TEM) and elemental analysis respectively. UV-vis spectrum is adopted to investigate interactions between functional groups ChS and HA. The results show that HA crystal nucleation and growth take place in chemical interactions between HA crystals and ChS as a template. And elemental analysis indicates that obtained HA contains a small amount of ChS. Furthermore, ChS concentration significantly affects the morphology of HA crystals. Staple-fiber-like HA crystals can be obtained at a low concentration in ChS, and flake-like HA crystals synthesized at a high concentration (≥0.5 wt.%) of ChS as a template.

Development of a spined underwater biomimetic vehicle with SMA actuators

NASA Astrophysics Data System (ADS)

Rediniotis, Othon K.; Lagoudas, Dimitris C.; Garner, Luke J.; Wilson, Larry N.

1999-06-01

We present here our progress towards the development of a type of biomimetic active hydrofoil that utilizes Shape Memory Alloy (SMA) actuator technology. The actuation is presently applied to the control of hydrodynamic forces and moments, including thrust generation, on a 2D hydrofoil. The SMA actuation elements are two sets of thin wires (0.015' to 0.027') on either side of an elastomer element that provides the main structural support. Controlled heating and cooling of the two wire sets generates bi-directional bending of the elastomer, which in turn deflects (for quasi-static control) or oscillates (for thrust generation) the trailing edge of the hydrofoil. The aquatic environment of the hydrofoil lends itself to cooling schemes that utilize the excellent heat transfer properties of water. The SMA actuator was able to deflect the trailing edge by +/- 5 degree(s) at rates as high as 2 Hz. FEM modeling of hydrofoil response to thermoelectric heating has been carried out using a thermomechanical constitutive model for SMAs. FEM predictions are compared with experimental measurements.

Cell membrane-based nanoparticles: a new biomimetic platform for tumor diagnosis and treatment.

PubMed

Li, Ruixiang; He, Yuwei; Zhang, Shuya; Qin, Jing; Wang, Jianxin

2018-01-01

Taking inspiration from nature, the biomimetic concept has been integrated into drug delivery systems in cancer therapy. Disguised with cell membranes, the nanoparticles can acquire various functions of natural cells. The cell membrane-coating technology has pushed the limits of common nano-systems (fast elimination in circulation) to more effectively navigate within the body. Moreover, because of the various functional molecules on the surface, cell membrane-based nanoparticles (CMBNPs) are capable of interacting with the complex biological microenvironment of the tumor. Various sources of cell membranes have been explored to camouflage CMBNPs and different tumor-targeting strategies have been developed to enhance the anti-tumor drug delivery therapy. In this review article we highlight the most recent advances in CMBNP-based cancer targeting systems and address the challenges and opportunities in this field.

Biomimetic Chemistry of Iron, Nickel, Molybdenum, and Tungsten in Sulfur-Ligated Protein Sites†

PubMed Central

Groysman, Stanislav; Holm, R. H.

2009-01-01

Biomimetic inorganic chemistry has as its primary goal the synthesis of molecules that approach or achieve the structures, oxidation states, and electronic and reactivity features of native metal-containing sites of variant nuclearity. Comparison of properties of accurate analogues and these sites ideally provides insight into the influence of protein structure and environment on intrinsic properties as represented by the analogue. For polynuclear sites in particular, the goal provides a formidable challenge for, with the exception of iron-sulfur clusters, all such site structures have never been achieved and few even closely approximated by chemical synthesis. This account describes the current status of the synthetic analogue approach as applied to the mononuclear sites in certain molybdoenzymes and the polynuclear sites in hydrogenases, nitrogenase, and carbon monoxide dehydrogenases. PMID:19206188

Catalytic molecularly imprinted polymer membranes: development of the biomimetic sensor for phenols detection.

PubMed

Sergeyeva, T A; Slinchenko, O A; Gorbach, L A; Matyushov, V F; Brovko, O O; Piletsky, S A; Sergeeva, L M; Elska, G V

2010-02-05

Portable biomimetic sensor devices for the express control of phenols content in water were developed. The synthetic binding sites mimicking active site of the enzyme tyrosinase were formed in the structure of free-standing molecularly imprinted polymer membranes. Molecularly imprinted polymer membranes with the catalytic activity were obtained by co-polymerization of the complex Cu(II)-catechol-urocanic acid ethyl ester with (tri)ethyleneglycoldimethacrylate, and oligourethaneacrylate. Addition of the elastic component oligourethaneacrylate provided formation of the highly cross-linked polymer with the catalytic activity in a form of thin, flexible, and mechanically stable membrane. High accessibility of the artificial catalytic sites for the interaction with the analyzed phenol molecules was achieved due to addition of linear polymer (polyethyleneglycol Mw 20,000) to the initial monomer mixture before the polymerization. As a result, typical semi-interpenetrating polymer networks (semi-IPNs) were formed. The cross-linked component of the semi-IPN was represented by the highly cross-linked catalytic molecularly imprinted polymer, while the linear one was represented by polyethyleneglycol Mw 20,000. Extraction of the linear polymer from the fully formed semi-IPN resulted in formation of large pores in the membranes' structure. Concentration of phenols in the analyzed samples was detected using universal portable device oxymeter with the oxygen electrode in a close contact with the catalytic molecularly imprinted polymer membrane as a transducer. The detection limit of phenols detection using the developed sensor system based on polymers-biomimics with the optimized composition comprised 0.063 mM, while the linear range of the sensor comprised 0.063-1 mM. The working characteristics of the portable sensor devices were investigated. Storage stability of sensor systems at room temperature comprised 12 months (87%). As compared to traditional methods of phenols

Oriented and Ordered Biomimetic Remineralization of the Surface of Demineralized Dental Enamel Using HAP@ACP Nanoparticles Guided by Glycine

PubMed Central

Wang, Haorong; Xiao, Zuohui; Yang, Jie; Lu, Danyang; Kishen, Anil; Li, Yanqiu; Chen, Zhen; Que, Kehua; Zhang, Qian; Deng, Xuliang; Yang, Xiaoping; Cai, Qing; Chen, Ning; Cong, Changhong; Guan, Binbin; Li, Ting; Zhang, Xu

2017-01-01

Achieving oriented and ordered remineralization on the surface of demineralized dental enamel, thereby restoring the satisfactory mechanical properties approaching those of sound enamel, is still a challenge for dentists. To mimic the natural biomineralization approach for enamel remineralization, the biological process of enamel development proteins, such as amelogenin, was simulated in this study. In this work, carboxymethyl chitosan (CMC) conjugated with alendronate (ALN) was applied to stabilize amorphous calcium phosphate (ACP) to form CMC/ACP nanoparticles. Sodium hypochlorite (NaClO) functioned as the protease which decompose amelogenin in vivo to degrade the CMC-ALN matrix and generate HAP@ACP core-shell nanoparticles. Finally, when guided by 10 mM glycine (Gly), HAP@ACP nanoparticles can arrange orderly and subsequently transform from an amorphous phase to well-ordered rod-like apatite crystals to achieve oriented and ordered biomimetic remineralization on acid-etched enamel surfaces. This biomimetic remineralization process is achieved through the oriented attachment (OA) of nanoparticles based on non-classical crystallization theory. These results indicate that finding and developing analogues of natural proteins such as amelogenin involved in the biomineralization by natural macromolecular polymers and imitating the process of biomineralization would be an effective strategy for enamel remineralization. Furthermore, this method represents a promising method for the management of early caries in minimal invasive dentistry (MID). PMID:28079165

Oriented and Ordered Biomimetic Remineralization of the Surface of Demineralized Dental Enamel Using HAP@ACP Nanoparticles Guided by Glycine

NASA Astrophysics Data System (ADS)

Wang, Haorong; Xiao, Zuohui; Yang, Jie; Lu, Danyang; Kishen, Anil; Li, Yanqiu; Chen, Zhen; Que, Kehua; Zhang, Qian; Deng, Xuliang; Yang, Xiaoping; Cai, Qing; Chen, Ning; Cong, Changhong; Guan, Binbin; Li, Ting; Zhang, Xu

2017-01-01

Achieving oriented and ordered remineralization on the surface of demineralized dental enamel, thereby restoring the satisfactory mechanical properties approaching those of sound enamel, is still a challenge for dentists. To mimic the natural biomineralization approach for enamel remineralization, the biological process of enamel development proteins, such as amelogenin, was simulated in this study. In this work, carboxymethyl chitosan (CMC) conjugated with alendronate (ALN) was applied to stabilize amorphous calcium phosphate (ACP) to form CMC/ACP nanoparticles. Sodium hypochlorite (NaClO) functioned as the protease which decompose amelogenin in vivo to degrade the CMC-ALN matrix and generate HAP@ACP core-shell nanoparticles. Finally, when guided by 10 mM glycine (Gly), HAP@ACP nanoparticles can arrange orderly and subsequently transform from an amorphous phase to well-ordered rod-like apatite crystals to achieve oriented and ordered biomimetic remineralization on acid-etched enamel surfaces. This biomimetic remineralization process is achieved through the oriented attachment (OA) of nanoparticles based on non-classical crystallization theory. These results indicate that finding and developing analogues of natural proteins such as amelogenin involved in the biomineralization by natural macromolecular polymers and imitating the process of biomineralization would be an effective strategy for enamel remineralization. Furthermore, this method represents a promising method for the management of early caries in minimal invasive dentistry (MID).

Maintenance and expansion of hematopoietic stem/progenitor cells in biomimetic osteoblast niche.

PubMed

Tan, Jing; Liu, Ting; Hou, Li; Meng, Wentong; Wang, Yuchun; Zhi, Wei; Deng, Li

2010-10-01

In this study, we employed bio-derived bone scaffold and composited with the marrow mesenchymal stem cell induced into osteoblast to replicate a "biomimetic niche." The CD34(+) cells or mononuclear cells (MNC) from umbilical cord blood were cultured for 2-5 weeks in the biomimetic niche (3D system) was compared with conventional two dimensional cultures (2D system) without adding cytokine supplement. After 2 weeks in culture, the CD34(+) cells from umbilical cord blood in the 3D system increased 3.3-4.8 folds when compared with the initial CD34(+) cells. CD34(+)/CD38(-) cells accounted for 82-90% of CD34(+) cells. After 5 weeks, CD34(+)/CD38(-) cells in the 3D system increased when compared with initial (1.3 ± 0.3 × 10(3) vs. 1.0 ± 0.5 × 10(4), p < 0.05), but were decreased in the 2D system (1.3 ± 0.3 × 10(3) vs. 2.5 ± 0.7 × 10(2), p < 0.05). The CFU progenitors were produced more in the 3D system than in the 2D system (4.6-9.3 folds vs. 1.0-1.5 folds) after 2 weeks in culture, and the colony distribution in the 3D system manifested higher percentage of BFU-E and CFU-GEMM, but in the 2D system was mainly CFU-GM. The LTC-ICs in the 3D system showed 5.2-7.2 folds increase over input at 2 weeks in culture, and maintain the immaturation of hematopoietic progenitor cells (HPCs) over 5 weeks. In conclusion, this new 3D hematopoietic progenitor cell culture system is the first to utilize natural cancellous bone as scaffold with osteoblasts as supporting cells; it is mimicry of natural bone marrow HSC niche. Our primary work has demonstrated it could maintain and expand HSC/HPC in vitro.

The cleaner, the greener? Product sustainability assessment of the biomimetic façade paint Lotusan® in comparison to the conventional façade paint Jumbosil®

PubMed Central

Antony, Florian; Grießhammer, Rainer; Speck, Thomas

2016-01-01

Background: The debate on the question whether biomimetics has a specific potential to contribute to sustainability is discussed among scientists, business leaders, politicians and those responsible for project funding. The objective of this paper is to contribute to this controversial debate by presenting the sustainability assessment of one of the most well-known and most successful biomimetic products: the façade paint Lotusan®. Results: As a first step it has been examined and verified that the façade paint Lotusan® is correctly defined as a biomimetic product. Secondly, Lotusan® has been assessed and compared to a conventional façade paint within the course of a detailed product sustainability assessment (PROSA). For purposes of comparison, the façade paint Jumbosil® was chosen as reference for a conventional paint available on the market. The benefit analysis showed that both paints fulfil equally well the requirements of functional utility. With respect to the symbolic utility, Lotusan® has a particular added aesthetic value by the preservation of the optical quality over the life cycle. Within the social analysis no substantial differences between the two paints could be found regarding the handling and disposal of the final products. Regarding the life-cycle cost, Lotusan® is the more expensive product. However, the higher investment cost for a Lotusan®-based façade painting are more than compensated by the longer life time, resulting in both reduced overall material demand and lower labour cost. In terms of the life-cycle impact assessment, it can be ascertained that substantial differences between the paints arise from the respective service life, which are presented in terms of four scenario analyses. Conclusion: In summary, the biomimetic façade paint Lotusan® has been identified as a cost-effective and at the same time resource-saving product. Based on the underlying data and assumptions it could be demonstrated that Lotusan®-based fa

The cleaner, the greener? Product sustainability assessment of the biomimetic façade paint Lotusan® in comparison to the conventional façade paint Jumbosil®.

PubMed

Antony, Florian; Grießhammer, Rainer; Speck, Thomas; Speck, Olga

2016-01-01

Background: The debate on the question whether biomimetics has a specific potential to contribute to sustainability is discussed among scientists, business leaders, politicians and those responsible for project funding. The objective of this paper is to contribute to this controversial debate by presenting the sustainability assessment of one of the most well-known and most successful biomimetic products: the façade paint Lotusan ® . Results: As a first step it has been examined and verified that the façade paint Lotusan ® is correctly defined as a biomimetic product. Secondly, Lotusan ® has been assessed and compared to a conventional façade paint within the course of a detailed product sustainability assessment (PROSA). For purposes of comparison, the façade paint Jumbosil ® was chosen as reference for a conventional paint available on the market. The benefit analysis showed that both paints fulfil equally well the requirements of functional utility. With respect to the symbolic utility, Lotusan ® has a particular added aesthetic value by the preservation of the optical quality over the life cycle. Within the social analysis no substantial differences between the two paints could be found regarding the handling and disposal of the final products. Regarding the life-cycle cost, Lotusan ® is the more expensive product. However, the higher investment cost for a Lotusan ® -based façade painting are more than compensated by the longer life time, resulting in both reduced overall material demand and lower labour cost. In terms of the life-cycle impact assessment, it can be ascertained that substantial differences between the paints arise from the respective service life, which are presented in terms of four scenario analyses. Conclusion: In summary, the biomimetic façade paint Lotusan ® has been identified as a cost-effective and at the same time resource-saving product. Based on the underlying data and assumptions it could be demonstrated that Lotusan �

Donor-Acceptor Distance Sampling Enhances the Performance of "Better than Nature" Nicotinamide Coenzyme Biomimetics.

PubMed

Geddes, Alexander; Paul, Caroline E; Hay, Sam; Hollmann, Frank; Scrutton, Nigel S

2016-09-07

Understanding the mechanisms of enzymatic hydride transfer with nicotinamide coenzyme biomimetics (NCBs) is critical to enhancing the performance of nicotinamide coenzyme-dependent biocatalysts. Here the temperature dependence of kinetic isotope effects (KIEs) for hydride transfer between "better than nature" NCBs and several ene reductase biocatalysts is used to indicate transfer by quantum mechanical tunneling. A strong correlation between rate constants and temperature dependence of the KIE (ΔΔH(⧧)) for H/D transfer implies that faster reactions with NCBs are associated with enhanced donor-acceptor distance sampling. Our analysis provides the first mechanistic insight into how NCBs can outperform their natural counterparts and emphasizes the need to optimize donor-acceptor distance sampling to obtain high catalytic performance from H-transfer enzymes.