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Sample records for 3d porous scaffold

  1. Preparation and mechanical property of a novel 3D porous magnesium scaffold for bone tissue engineering.

    PubMed

    Zhang, Xue; Li, Xiao-Wu; Li, Ji-Guang; Sun, Xu-Dong

    2014-09-01

    Porous magnesium has been recently recognized as a biodegradable metal for bone substitute applications. A novel porous Mg scaffold with three-dimensional (3D) interconnected pores and with a porosity of 33-54% was produced by the fiber deposition hot pressing (FDHP) technology. The microstructure and morphologies of the porous Mg scaffold were characterized by scanning electron microscopy (SEM), and the effects of porosities on the microstructure and mechanical properties of the porous Mg were investigated. Experimental results indicate that the measured Young's modulus and compressive strength of the Mg scaffold are ranged in 0.10-0.37 GPa, and 11.1-30.3 MPa, respectively, which are fairly comparable to those of cancellous bone. Such a porous Mg scaffold having a 3D interconnected network structure has the potential to be used in bone tissue engineering.

  2. Mechanical properties and shape memory effect of 3D-printed PLA-based porous scaffolds.

    PubMed

    Senatov, F S; Niaza, K V; Zadorozhnyy, M Yu; Maksimkin, A V; Kaloshkin, S D; Estrin, Y Z

    2016-04-01

    In the present work polylactide (PLA)/15wt% hydroxyapatite (HA) porous scaffolds with pre-modeled structure were obtained by 3D-printing by fused filament fabrication. Composite filament was obtained by extrusion. Mechanical properties, structural characteristics and shape memory effect (SME) were studied. Direct heating was used for activation of SME. The average pore size and porosity of the scaffolds were 700μm and 30vol%, respectively. Dispersed particles of HA acted as nucleation centers during the ordering of PLA molecular chains and formed an additional rigid fixed phase that reduced molecular mobility, which led to a shift of the onset of recovery stress growth from 53 to 57°C. A more rapid development of stresses was observed for PLA/HA composites with the maximum recovery stress of 3.0MPa at 70°C. Ceramic particles inhibited the growth of cracks during compression-heating-compression cycles when porous PLA/HA 3D-scaffolds recovered their initial shape. Shape recovery at the last cycle was about 96%. SME during heating may have resulted in "self-healing" of scaffold by narrowing the cracks. PLA/HA 3D-scaffolds were found to withstand up to three compression-heating-compression cycles without delamination. It was shown that PLA/15%HA porous scaffolds obtained by 3D-printing with shape recovery of 98% may be used as self-fitting implant for small bone defect replacement owing to SME.

  3. Preparation and Evaluation of Gelatin-Chitosan-Nanobioglass 3D Porous Scaffold for Bone Tissue Engineering

    PubMed Central

    Maji, Kanchan; Dasgupta, Sudip; Pramanik, Krishna; Bissoyi, Akalabya

    2016-01-01

    The aim of the present study was to prepare and characterize bioglass-natural biopolymer based composite scaffold and evaluate its bone regeneration ability. Bioactive glass nanoparticles (58S) in the size range of 20–30 nm were synthesized using sol-gel method. Porous scaffolds with varying bioglass composition from 10 to 30 wt% in chitosan, gelatin matrix were fabricated using the method of freeze drying of its slurry at 40 wt% solids loading. Samples were cross-linked with glutaraldehyde to obtain interconnected porous 3D microstructure with improved mechanical strength. The prepared scaffolds exhibited >80% porosity with a mean pore size range between 100 and 300 microns. Scaffold containing 30 wt% bioglass (GCB 30) showed a maximum compressive strength of 2.2 ± 0.1 MPa. Swelling and degradation studies showed that the scaffold had excellent properties of hydrophilicity and biodegradability. GCB 30 scaffold was shown to be noncytotoxic and supported mesenchymal stem cell attachment, proliferation, and differentiation as indicated by MTT assay and RUNX-2 expression. Higher cellular activity was observed in GCB 30 scaffold as compared to GCB 0 scaffold suggesting the fact that 58S bioglass nanoparticles addition into the scaffold promoted better cell adhesion, proliferation, and differentiation. Thus, the study showed that the developed composite scaffolds are potential candidates for regenerating damaged bone tissue. PMID:26884764

  4. Bottom-up topography assembly into 3D porous scaffold to mediate cell activities.

    PubMed

    Cheng, Delin; Hou, Jie; Hao, Lijing; Cao, Xiaodong; Gao, Huichang; Fu, Xiaoling; Wang, Yingjun

    2016-08-01

    Native cells live in a three-dimensional (3D) extracellular matrix (ECM) capable of regulating cell activities through various physical and chemical factors. Designed topographies have been well proven to trigger significant difference in cell behaviours. However, present topographies are almost all constructed on two-dimensional (2D) substrates like discs and films, which are far from features like 3D and porosity required in application like bone repair. Here we bottom-up assembled poly(lactic-co-glycolic acid)/calcium carbonate (PLGA/CC) microspheres with superficial porous topography intactly into a 3D porous scaffold. Because the scaffold was obtained through a mild technique, the bioactivity of released BMP-2 was well retained. Mouse bone marrow mesenchymal stem cells (mMSCs) were cultured on produced scaffolds having different 3D topographies. It turned out that osteogenic differentiation of mMSCs did respond to the 3D topographies, while proliferation didn't. Gene expression of αv and β1 integrins revealed that adhesion was supposed to be the underlying mechanism for osteogenic response. The study provides insight into enhancing function of practical scaffolds by elaborate topography design. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 104B: 1056-1063, 2016.

  5. Modeling and Reconstruction of Micro-structured 3D Chitosan/Gelatin Porous Scaffolds Using Micro-CT

    NASA Astrophysics Data System (ADS)

    Gong, Haibo; Li, Dichen; He, Jiankang; Liu, Yaxiong; Lian, Qin; Zhao, Jinna

    2008-09-01

    Three dimensional (3D) channel networks are the key to promise the uniform distribution of nutrients inside 3D hepatic tissue engineering scaffolds and prompt elimination of metabolic products out of the scaffolds. 3D chitosan/gelatin porous scaffolds with predefined internal channels were fabricated and a combination of light microscope, laser confocal microscopy and micro-CT were employed to characterize the structure of porous scaffolds. In order to evaluate the flow field distribution inside the micro-structured 3D scaffolds, a computer reconstructing method based on Micro-CT was proposed. According to this evaluating method, a contrast between 3D porous scaffolds with and without predefined internal channels was also performed to assess scaffolds' fluid characters. Results showed that the internal channel of the 3D scaffolds formed the 3D fluid channel network; the uniformity of flow field distribution of the scaffolds fabricated in this paper was better than the simple porous scaffold without micro-fluid channels.

  6. Evaluation of 3D nano-macro porous bioactive glass scaffold for hard tissue engineering.

    PubMed

    Wang, S; Falk, M M; Rashad, A; Saad, M M; Marques, A C; Almeida, R M; Marei, M K; Jain, H

    2011-05-01

    Recently, nano-macro dual-porous, three-dimensional (3D) glass structures were developed for use as bioscaffolds for hard tissue regeneration, but there have been concerns regarding the interconnectivity and homogeneity of nanopores in the scaffolds, as well as the cytotoxicity of the environment deep inside due to limited fluid access. Therefore, mercury porosimetry, nitrogen absorption, and TEM have been used to characterize nanopore network of the scaffolds. In parallel, viability of MG 63 human osteosarcoma cells seeded on scaffold surface was investigated by fluorescence, confocal and electron microscopy methods. The results show that cells attach, migrate and penetrate inside the glass scaffold with high proliferation and viability rate. Additionally, scaffolds were implanted under the skin of a male New Zealand rabbit for in vivo animal test. Initial observations show the formation of new tissue with blood vessels and collagen fibers deep inside the implanted scaffolds with no obvious inflammatory reaction. Thus, the new nano-macro dual-porous glass structure could be a promising bioscaffold for use in regenerative medicine and tissue engineering for bone regeneration. PMID:21445655

  7. 3D printing of porous hydroxyapatite scaffolds intended for use in bone tissue engineering applications.

    PubMed

    Cox, Sophie C; Thornby, John A; Gibbons, Gregory J; Williams, Mark A; Mallick, Kajal K

    2015-02-01

    A systematic characterisation of bone tissue scaffolds fabricated via 3D printing from hydroxyapatite (HA) and poly(vinyl)alcohol (PVOH) composite powders is presented. Flowability of HA:PVOH precursor materials was observed to affect mechanical stability, microstructure and porosity of 3D printed scaffolds. Anisotropic behaviour of constructs and part failure at the boundaries of interlayer bonds was highlighted by compressive strength testing. A trade-off between the ability to facilitate removal of PVOH thermal degradation products during sintering and the compressive strength of green parts was revealed. The ultimate compressive strength of 55% porous green scaffolds printed along the Y-axis and dried in a vacuum oven for 6h was 0.88 ± 0.02 MPa. Critically, the pores of 3D printed constructs could be user designed, ensuring bulk interconnectivity, and the imperfect packing of powder particles created an inherent surface roughness and non-designed porosity within the scaffold. These features are considered promising since they are known to facilitate osteoconduction and osteointegration in-vivo. Characterisation techniques utilised in this study include two funnel flow tests, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), compressive strength testing and computed tomography (CT).

  8. 3D printing of porous hydroxyapatite scaffolds intended for use in bone tissue engineering applications.

    PubMed

    Cox, Sophie C; Thornby, John A; Gibbons, Gregory J; Williams, Mark A; Mallick, Kajal K

    2015-02-01

    A systematic characterisation of bone tissue scaffolds fabricated via 3D printing from hydroxyapatite (HA) and poly(vinyl)alcohol (PVOH) composite powders is presented. Flowability of HA:PVOH precursor materials was observed to affect mechanical stability, microstructure and porosity of 3D printed scaffolds. Anisotropic behaviour of constructs and part failure at the boundaries of interlayer bonds was highlighted by compressive strength testing. A trade-off between the ability to facilitate removal of PVOH thermal degradation products during sintering and the compressive strength of green parts was revealed. The ultimate compressive strength of 55% porous green scaffolds printed along the Y-axis and dried in a vacuum oven for 6h was 0.88 ± 0.02 MPa. Critically, the pores of 3D printed constructs could be user designed, ensuring bulk interconnectivity, and the imperfect packing of powder particles created an inherent surface roughness and non-designed porosity within the scaffold. These features are considered promising since they are known to facilitate osteoconduction and osteointegration in-vivo. Characterisation techniques utilised in this study include two funnel flow tests, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), compressive strength testing and computed tomography (CT). PMID:25492194

  9. Osteogenic effect of controlled released rhBMP-2 in 3D printed porous hydroxyapatite scaffold.

    PubMed

    Wang, Hai; Wu, Gui; Zhang, Jing; Zhou, Kui; Yin, Bo; Su, Xinlin; Qiu, Guixing; Yang, Guang; Zhang, Xianglin; Zhou, Gang; Wu, Zhihong

    2016-05-01

    Recently, 3D printing as effective technology has been highlighted in the biomedical field. Previously, a porous hydroxyapatite (HA) scaffold with the biocompatibility and osteoconductivity has been developed by this method. However, its osteoinductivity is limited. The main purpose of this study was to improve it by the introduction of recombinant human bone morphogenetic protein-2 (rhBMP-2). This scaffold was developed by coating rhBMP-2-delivery microspheres with collagen. These synthesized scaffolds were characterized by Scanning Electron Microscopy (SEM), a delivery test in vitro, cell culture, and the experiments in vivo by a Micro-computed tomography (μCT) scan and histological evaluation of VanGieson staining. SEM results indicated the surface of scaffolds were more fit for the adhesion of hMSCs to coat collagen/rhBMP-2 microspheres. Biphasic release of rhBMP-2 could continue for more than 21 days, and keep its osteoinductivity to induce osteogenic differentiation of hMSCs in vitro. In addition, the experiments in vivo showed that the scaffold had a good bone regeneration capacity. These findings demonstrate that the HA/Collagen/Chitosan Microspheres system can simultaneously achieve localized long-term controlled release of rhBMP-2 and bone regeneration, which provides a promising route for improving the treatment of bone defects.

  10. 3D Printing Bioceramic Porous Scaffolds with Good Mechanical Property and Cell Affinity.

    PubMed

    Chang, Chih-Hao; Lin, Chih-Yang; Liu, Fwu-Hsing; Chen, Mark Hung-Chih; Lin, Chun-Pin; Ho, Hong-Nerng; Liao, Yunn-Shiuan

    2015-01-01

    Artificial bone grafting is widely used in current orthopedic surgery for bone defect problems. Unfortunately, surgeons remain unsatisfied with the current commercially available products. One of the major complaints is that these products cannot provide sufficient mechanical strength to support the human skeletal structure. In this study, we aimed to develop a bone scaffold with better mechanical property and good cell affinity by 3D printing (3DP) techniques. A self-developed 3D printer with laser-aided gelling (LAG) process was used to fabricate bioceramic scaffolds with inter-porous structures. To improve the mechanical property of the bioceramic parts after heating, CaCO3 was added to the silica ceramic slurry. CaCO3 was blended into a homogenous SiO2-sol dispersion at weight ratios varying from 0/100 to 5/95 to 9/91 (w/w). Bi-component CaCO3/SiO2-sol was prepared as a biocomposite for the 3DP scaffold. The well-mixed biocomposite was used to fabricate the bioceramic green part using the LAG method. The varied scaffolds were sintered at different temperatures ranging from 900 to 1500°C, and the mechanical property was subsequently analyzed. The scaffolds showed good property with the composite ratio of 5:95 CaCO3:SiO2 at a sintering temperature of 1300°C. The compressive strength was 47 MPa, and the porosity was 34%. The topography of the sintered 3DP bioceramic scaffold was examined by SEM, EDS and XRD. The silica bioceramic presented no cytotoxicity and good MG-63 osteoblast-like cell affinity, demonstrating good biocompatibility. Therefore, the new silica biocomposite is viable for fabricating 3DP bone bioceramics with improved mechanical property and good cell affinity. PMID:26618362

  11. 3D Printing Bioceramic Porous Scaffolds with Good Mechanical Property and Cell Affinity

    PubMed Central

    Chang, Chih-Hao; Lin, Chih-Yang; Liu, Fwu-Hsing; Chen, Mark Hung-Chih; Lin, Chun-Pin; Ho, Hong-Nerng; Liao, Yunn-Shiuan

    2015-01-01

    Artificial bone grafting is widely used in current orthopedic surgery for bone defect problems. Unfortunately, surgeons remain unsatisfied with the current commercially available products. One of the major complaints is that these products cannot provide sufficient mechanical strength to support the human skeletal structure. In this study, we aimed to develop a bone scaffold with better mechanical property and good cell affinity by 3D printing (3DP) techniques. A self-developed 3D printer with laser-aided gelling (LAG) process was used to fabricate bioceramic scaffolds with inter-porous structures. To improve the mechanical property of the bioceramic parts after heating, CaCO3 was added to the silica ceramic slurry. CaCO3 was blended into a homogenous SiO2-sol dispersion at weight ratios varying from 0/100 to 5/95 to 9/91 (w/w). Bi-component CaCO3/SiO2-sol was prepared as a biocomposite for the 3DP scaffold. The well-mixed biocomposite was used to fabricate the bioceramic green part using the LAG method. The varied scaffolds were sintered at different temperatures ranging from 900 to 1500°C, and the mechanical property was subsequently analyzed. The scaffolds showed good property with the composite ratio of 5:95 CaCO3:SiO2 at a sintering temperature of 1300°C. The compressive strength was 47 MPa, and the porosity was 34%. The topography of the sintered 3DP bioceramic scaffold was examined by SEM, EDS and XRD. The silica bioceramic presented no cytotoxicity and good MG-63 osteoblast-like cell affinity, demonstrating good biocompatibility. Therefore, the new silica biocomposite is viable for fabricating 3DP bone bioceramics with improved mechanical property and good cell affinity. PMID:26618362

  12. 3D Printing Bioceramic Porous Scaffolds with Good Mechanical Property and Cell Affinity.

    PubMed

    Chang, Chih-Hao; Lin, Chih-Yang; Liu, Fwu-Hsing; Chen, Mark Hung-Chih; Lin, Chun-Pin; Ho, Hong-Nerng; Liao, Yunn-Shiuan

    2015-01-01

    Artificial bone grafting is widely used in current orthopedic surgery for bone defect problems. Unfortunately, surgeons remain unsatisfied with the current commercially available products. One of the major complaints is that these products cannot provide sufficient mechanical strength to support the human skeletal structure. In this study, we aimed to develop a bone scaffold with better mechanical property and good cell affinity by 3D printing (3DP) techniques. A self-developed 3D printer with laser-aided gelling (LAG) process was used to fabricate bioceramic scaffolds with inter-porous structures. To improve the mechanical property of the bioceramic parts after heating, CaCO3 was added to the silica ceramic slurry. CaCO3 was blended into a homogenous SiO2-sol dispersion at weight ratios varying from 0/100 to 5/95 to 9/91 (w/w). Bi-component CaCO3/SiO2-sol was prepared as a biocomposite for the 3DP scaffold. The well-mixed biocomposite was used to fabricate the bioceramic green part using the LAG method. The varied scaffolds were sintered at different temperatures ranging from 900 to 1500°C, and the mechanical property was subsequently analyzed. The scaffolds showed good property with the composite ratio of 5:95 CaCO3:SiO2 at a sintering temperature of 1300°C. The compressive strength was 47 MPa, and the porosity was 34%. The topography of the sintered 3DP bioceramic scaffold was examined by SEM, EDS and XRD. The silica bioceramic presented no cytotoxicity and good MG-63 osteoblast-like cell affinity, demonstrating good biocompatibility. Therefore, the new silica biocomposite is viable for fabricating 3DP bone bioceramics with improved mechanical property and good cell affinity.

  13. Highly Porous Gelatin Reinforced 3D Scaffolds for Articular Cartilage Regeneration.

    PubMed

    Amadori, Sofia; Torricelli, Paola; Panzavolta, Silvia; Parrilli, Annapaola; Fini, Milena; Bigi, Adriana

    2015-07-01

    3D highly porous (93% total porosity) gelatin scaffolds were prepared according to a novel, simple method, which implies gelatin foaming, gelification, soaking into ethanol and successive freeze-drying. Reinforcement of the as-prepared scaffolds (GEL) was performed through immersion in aqueous solutions at different gelatin concentrations. Reinforcement solutions with and without genipin addition allowed to prepare two series of samples:cross-linked and uncross-linked samples, respectively. The amount of gelatin adsorbed onto the reinforced samples increases as a function of gelatin concentration in solution and provokes a drastic improvement of the compressive modulus and collapse strength up to values of about 30 and 4 MPa, respectively. The open and interconnected porosity, although slightly reduced, is still of the order of 80% in the samples reinforced with the highest concentration of gelatin. Water uptake ability evaluated after immersion in PBS for 20 s decreases with gelatin reinforcement. The presence of genipin in cross-linked samples reduces gelatin release and stabilizes the scaffolds in solution. Chondrocytes from human articular cartilage adhere, proliferate, and penetrate into the scaffolds. The evaluation of differentiation markers both on the supernatants of cell culture and by means of quantitative polymerase chain reaction (qPCR) indicates a dose-dependent promotion of cell differentiation.

  14. Surface functionalization of 3D glass-ceramic porous scaffolds for enhanced mineralization in vitro

    NASA Astrophysics Data System (ADS)

    Ferraris, Sara; Vitale-Brovarone, Chiara; Bretcanu, Oana; Cassinelli, Clara; Vernè, Enrica

    2013-04-01

    Bone reconstruction after tissue loosening due to traumatic, pathological or surgical causes is in increasing demand. 3D scaffolds are a widely studied solution for supporting new bone growth. Bioactive glass-ceramic porous materials can offer a three-dimensional structure that is able to chemically bond to bone. The ability to surface modify these devices by grafting biologically active molecules represents a challenge, with the aim of stimulating physiological bone regeneration with both inorganic and organic signals. In this research work glass ceramic scaffolds with very high mechanical properties and moderate bioactivity have been functionalized with the enzyme alkaline phosphatase (ALP). The material surface was activated in order to expose hydroxyl groups. The activated surface was further grafted with ALP both via silanization and also via direct grafting to the surface active hydroxyl groups. Enzymatic activity of grafted samples were measured by means of UV-vis spectroscopy before and after ultrasonic washing in TRIS-HCl buffer solution. In vitro inorganic bioactivity was investigated by soaking the scaffolds after the different steps of functionalization in a simulated body fluid (SBF). SEM observations allowed the monitoring of the scaffold morphology and surface chemical composition after soaking in SBF. The presence of ALP enhanced the in vitro inorganic bioactivity of the tested material.

  15. Laser 3D printing with sub-microscale resolution of porous elastomeric scaffolds for supporting human bone stem cells.

    PubMed

    Petrochenko, Peter E; Torgersen, Jan; Gruber, Peter; Hicks, Lucas A; Zheng, Jiwen; Kumar, Girish; Narayan, Roger J; Goering, Peter L; Liska, Robert; Stampfl, Jürgen; Ovsianikov, Aleksandr

    2015-04-01

    A reproducible method is needed to fabricate 3D scaffold constructs that results in periodic and uniform structures with precise control at sub-micrometer and micrometer length scales. In this study, fabrication of scaffolds by two-photon polymerization (2PP) of a biodegradable urethane and acrylate-based photoelastomer is demonstrated. This material supports 2PP processing with sub-micrometer spatial resolution. The high photoreactivity of the biophotoelastomer permits 2PP processing at a scanning speed of 1000 mm s(-1), facilitating rapid fabrication of relatively large structures (>5 mm(3)). These structures are custom printed for in vitro assay screening in 96-well plates and are sufficiently flexible to enable facile handling and transplantation. These results indicate that stable scaffolds with porosities of greater than 60% can be produced using 2PP. Human bone marrow stromal cells grown on 3D scaffolds exhibit increased growth and proliferation compared to smooth 2D scaffold controls. 3D scaffolds adsorb larger amounts of protein than smooth 2D scaffolds due to their larger surface area; the scaffolds also allow cells to attach in multiple planes and to completely infiltrate the porous scaffolds. The flexible photoelastomer material is biocompatible in vitro and is associated with facile handling, making it a viable candidate for further study of complex 3D-printed scaffolds.

  16. Microfabrication of complex porous tissue engineering scaffolds using 3D projection stereolithography

    PubMed Central

    Gauvin, Robert; Chen, Ying-Chieh; Lee, Jin Woo; Soman, Pranav; Zorlutuna, Pinar; Nichol, Jason W.; Bae, Hojae; Chen, Shaochen; Khademhosseini, Ali

    2013-01-01

    The success of tissue engineering will rely on the ability to generate complex, cell seeded three-dimensional (3D) structures. Therefore, methods that can be used to precisely engineer the architecture and topography of scaffolding materials will represent a critical aspect of functional tissue engineering. Previous approaches for 3D scaffold fabrication based on top-down and process driven methods are often not adequate to produce complex structures due to the lack of control on scaffold architecture, porosity, and cellular interactions. The proposed projection stereolithography (PSL) platform can be used to design intricate 3D tissue scaffolds that can be engineered to mimic the microarchitecture of tissues, based on computer aided design (CAD). The PSL system was developed, programmed and optimized to fabricate 3D scaffolds using gelatin methacrylate (GelMA). Variation of the structure and prepolymer concentration enabled tailoring the mechanical properties of the scaffolds. A dynamic cell seeding method was utilized to improve the coverage of the scaffold throughout its thickness. The results demonstrated that the interconnectivity of pores allowed for uniform human umbilical vein endothelial cells (HUVECs) distribution and proliferation in the scaffolds, leading to high cell density and confluency at the end of the culture period. Moreover, immunohistochemistry results showed that cells seeded on the scaffold maintained their endothelial phenotype, demonstrating the biological functionality of the microfabricated GelMA scaffolds. PMID:22365811

  17. Microfabrication of complex porous tissue engineering scaffolds using 3D projection stereolithography.

    PubMed

    Gauvin, Robert; Chen, Ying-Chieh; Lee, Jin Woo; Soman, Pranav; Zorlutuna, Pinar; Nichol, Jason W; Bae, Hojae; Chen, Shaochen; Khademhosseini, Ali

    2012-05-01

    The success of tissue engineering will rely on the ability to generate complex, cell seeded three-dimensional (3D) structures. Therefore, methods that can be used to precisely engineer the architecture and topography of scaffolding materials will represent a critical aspect of functional tissue engineering. Previous approaches for 3D scaffold fabrication based on top-down and process driven methods are often not adequate to produce complex structures due to the lack of control on scaffold architecture, porosity, and cellular interactions. The proposed projection stereolithography (PSL) platform can be used to design intricate 3D tissue scaffolds that can be engineered to mimic the microarchitecture of tissues, based on computer aided design (CAD). The PSL system was developed, programmed and optimized to fabricate 3D scaffolds using gelatin methacrylate (GelMA). Variation of the structure and prepolymer concentration enabled tailoring the mechanical properties of the scaffolds. A dynamic cell seeding method was utilized to improve the coverage of the scaffold throughout its thickness. The results demonstrated that the interconnectivity of pores allowed for uniform human umbilical vein endothelial cells (HUVECs) distribution and proliferation in the scaffolds, leading to high cell density and confluency at the end of the culture period. Moreover, immunohistochemistry results showed that cells seeded on the scaffold maintained their endothelial phenotype, demonstrating the biological functionality of the microfabricated GelMA scaffolds.

  18. Urethral reconstruction with a 3D porous bacterial cellulose scaffold seeded with lingual keratinocytes in a rabbit model.

    PubMed

    Huang, Jian-Wen; Lv, Xiang-Guo; Li, Zhe; Song, Lu-Jie; Feng, Chao; Xie, Min-Kai; Li, Chao; Li, Hong-Bin; Wang, Ji-Hong; Zhu, Wei-Dong; Chen, Shi-Yan; Wang, Hua-Ping; Xu, Yue-Min

    2015-09-01

    The goal of this study was to evaluate the effects of urethral reconstruction with a three-dimensional (3D) porous bacterial cellulose (BC) scaffold seeded with lingual keratinocytes in a rabbit model. A novel 3D porous BC scaffold was prepared by gelatin sponge interfering in the BC fermentation process. Rabbit lingual keratinocytes were isolated, expanded, and seeded onto 3D porous BC. BC alone (group 1, N  =  10), 3D porous BC alone (group 2, N  =  10), and 3D porous BC seeded with lingual keratinocytes (group 3, N  =  10) were used to repair rabbit ventral urethral defects (2.0   ×   0.8 cm). Scanning electron microscopy revealed that BC consisted of a compact laminate while 3D porous BC was composed of a porous sheet buttressed by a dense outer layer. The average pore diameter and porosity of the 3D porous BC were 4.23   ±   1.14 μm and 67.00   ±   6.80%, respectively. At 3 months postoperatively, macroscopic examinations and retrograde urethrograms of urethras revealed that all urethras maintained wide calibers in group 3. Strictures were found in all rabbits in groups 1 and 2. Histologically, at 1 month postoperatively, intact epithelium occurred in group 3, and discontinued epithelium was found in groups 1 and 2. However, groups 2 and 3 exhibited similar epithelial regeneration, which was superior to that of group 1 at 3 months (p  <  0.05). Comparisons of smooth muscle content and endothelia density among the three groups revealed a significant increase at each time point (p  <  0.05). Our results demonstrated that 3D porous BC seeded with lingual keratinocytes enhanced urethral tissue regeneration. 3D porous BC could potentially be used as an optimized scaffold for urethral reconstruction. PMID:26358641

  19. Urethral reconstruction with a 3D porous bacterial cellulose scaffold seeded with lingual keratinocytes in a rabbit model.

    PubMed

    Huang, Jian-Wen; Lv, Xiang-Guo; Li, Zhe; Song, Lu-Jie; Feng, Chao; Xie, Min-Kai; Li, Chao; Li, Hong-Bin; Wang, Ji-Hong; Zhu, Wei-Dong; Chen, Shi-Yan; Wang, Hua-Ping; Xu, Yue-Min

    2015-09-11

    The goal of this study was to evaluate the effects of urethral reconstruction with a three-dimensional (3D) porous bacterial cellulose (BC) scaffold seeded with lingual keratinocytes in a rabbit model. A novel 3D porous BC scaffold was prepared by gelatin sponge interfering in the BC fermentation process. Rabbit lingual keratinocytes were isolated, expanded, and seeded onto 3D porous BC. BC alone (group 1, N  =  10), 3D porous BC alone (group 2, N  =  10), and 3D porous BC seeded with lingual keratinocytes (group 3, N  =  10) were used to repair rabbit ventral urethral defects (2.0   ×   0.8 cm). Scanning electron microscopy revealed that BC consisted of a compact laminate while 3D porous BC was composed of a porous sheet buttressed by a dense outer layer. The average pore diameter and porosity of the 3D porous BC were 4.23   ±   1.14 μm and 67.00   ±   6.80%, respectively. At 3 months postoperatively, macroscopic examinations and retrograde urethrograms of urethras revealed that all urethras maintained wide calibers in group 3. Strictures were found in all rabbits in groups 1 and 2. Histologically, at 1 month postoperatively, intact epithelium occurred in group 3, and discontinued epithelium was found in groups 1 and 2. However, groups 2 and 3 exhibited similar epithelial regeneration, which was superior to that of group 1 at 3 months (p  <  0.05). Comparisons of smooth muscle content and endothelia density among the three groups revealed a significant increase at each time point (p  <  0.05). Our results demonstrated that 3D porous BC seeded with lingual keratinocytes enhanced urethral tissue regeneration. 3D porous BC could potentially be used as an optimized scaffold for urethral reconstruction.

  20. Development and characterization of novel porous 3D alginate-cockle shell powder nanobiocomposite bone scaffold.

    PubMed

    Bharatham, B Hemabarathy; Abu Bakar, Md Zuki; Perimal, Enoch Kumar; Yusof, Loqman Mohamed; Hamid, Muhajir

    2014-01-01

    A novel porous three-dimensional bone scaffold was developed using a natural polymer (alginate/Alg) in combination with a naturally obtained biomineral (nano cockle shell powder/nCP) through lyophilization techniques. The scaffold was developed in varying composition mixture of Alg-nCP and characterized using various evaluation techniques as well as preliminary in vitro studies on MG63 human osteoblast cells. Morphological observations using SEM revealed variations in structures with the use of different Alg-nCP composition ratios. All the developed scaffolds showed a porous structure with pore sizes ideal for facilitating new bone growth; however, not all combination mixtures showed subsequent favorable characteristics to be used for biological applications. Scaffolds produced using the combination mixture of 40% Alg and 60% nCP produced significantly promising results in terms of mechanical strength, degradation rate, and increased cell proliferation rates making it potentially the optimum composition mixture of Alg-nCP with future application prospects.

  1. In vitro cartilage tissue engineering with 3D porous aqueous-derived silk scaffolds and mesenchymal stem cells.

    PubMed

    Wang, Yongzhong; Kim, Ung-Jin; Blasioli, Dominick J; Kim, Hyeon-Joo; Kaplan, David L

    2005-12-01

    Adult cartilage tissue has limited self-repair capacity, especially in the case of severe damages caused by developmental abnormalities, trauma, or aging-related degeneration like osteoarthritis. Adult mesenchymal stem cells (MSCs) have the potential to differentiate into cells of different lineages including bone, cartilage, and fat. In vitro cartilage tissue engineering using autologous MSCs and three-dimensional (3-D) porous scaffolds has the potential for the successful repair of severe cartilage damage. Ideally, scaffolds designed for cartilage tissue engineering should have optimal structural and mechanical properties, excellent biocompatibility, controlled degradation rate, and good handling characteristics. In the present work, a novel, highly porous silk scaffold was developed by an aqueous process according to these criteria and subsequently combined with MSCs for in vitro cartilage tissue engineering. Chondrogenesis of MSCs in the silk scaffold was evident by real-time RT-PCR analysis for cartilage-specific ECM gene markers, histological and immunohistochemical evaluations of cartilage-specific ECM components. Dexamethasone and TGF-beta3 were essential for the survival, proliferation and chondrogenesis of MSCs in the silk scaffolds. The attachment, proliferation, and differentiation of MSCs in the silk scaffold showed unique characteristics. After 3 weeks of cultivation, the spatial cell arrangement and the collagen type-II distribution in the MSCs-silk scaffold constructs resembles those in native articular cartilage tissue, suggesting promise for these novel 3-D degradable silk-based scaffolds in MSC-based cartilage repair. Further in vivo evaluation is necessary to fully recognize the clinical relevance of these observations.

  2. Development and characterization of novel porous 3D alginate-cockle shell powder nanobiocomposite bone scaffold.

    PubMed

    Bharatham, B Hemabarathy; Abu Bakar, Md Zuki; Perimal, Enoch Kumar; Yusof, Loqman Mohamed; Hamid, Muhajir

    2014-01-01

    A novel porous three-dimensional bone scaffold was developed using a natural polymer (alginate/Alg) in combination with a naturally obtained biomineral (nano cockle shell powder/nCP) through lyophilization techniques. The scaffold was developed in varying composition mixture of Alg-nCP and characterized using various evaluation techniques as well as preliminary in vitro studies on MG63 human osteoblast cells. Morphological observations using SEM revealed variations in structures with the use of different Alg-nCP composition ratios. All the developed scaffolds showed a porous structure with pore sizes ideal for facilitating new bone growth; however, not all combination mixtures showed subsequent favorable characteristics to be used for biological applications. Scaffolds produced using the combination mixture of 40% Alg and 60% nCP produced significantly promising results in terms of mechanical strength, degradation rate, and increased cell proliferation rates making it potentially the optimum composition mixture of Alg-nCP with future application prospects. PMID:25110655

  3. Characterization of Silk Fibroin/Chitosan 3D Porous Scaffold and In Vitro Cytology

    PubMed Central

    Zeng, Shuguang; Liu, Lei; Shi, Yong; Qiu, Junqi; Fang, Wei; Rong, Mingdeng; Guo, Zehong; Gao, Wenfeng

    2015-01-01

    Bone tissue engineering is a powerful tool to treat bone defects caused by trauma, infection, tumors and other factors. Both silk fibroin (SF) and chitosan (CS) are non-toxic and have good biocompatibility, but are poor biological scaffolds when used alone. In this study, the microscopic structure and related properties of SF/CS composite scaffolds with different component ratios were examined. The scaffold material most suitable for osteoblast growth was determined, and these results offer an experimental basis for the future reconstruction of bone defects. First, via freeze-drying and chemical crosslinking methods, SF/CS composites with different component ratios were prepared and their structure was characterized. Changes in the internal structure of the SF and CS mixture were observed, confirming that the mutual modification between the two components was complete and stable. The internal structure of the composite material was porous and three-dimensional with a porosity above 90%. We next studied the pore size, swelling ratio, water absorption ratio, degradation and in vitro cell proliferation. For the 40% SF-60% CS group, the pore size of the scaffold was suitable for the growth of osteoblasts, and the rate of degradation was steady. This favors the early adhesion, growth and proliferation of MG-63 cells. In addition to good biocompatibility and satisfactory cell affinity, this material promotes the secretion of extracellular matrix materials by osteoblasts. Thus, 40% SF-60% CS is a good material for bone tissue engineering. PMID:26083846

  4. Fabrication of 3D porous SF/β-TCP hybrid scaffolds for bone tissue reconstruction.

    PubMed

    Park, Hyun Jung; Min, Kyung Dan; Lee, Min Chae; Kim, Soo Hyeon; Lee, Ok Joo; Ju, Hyung Woo; Moon, Bo Mi; Lee, Jung Min; Park, Ye Ri; Kim, Dong Wook; Jeong, Ju Yeon; Park, Chan Hum

    2016-07-01

    Bio-ceramic is a biomaterial actively studied in the field of bone tissue engineering. But, only certain ceramic materials can resolve the corrosion problem and possess the biological affinity of conventional metal biomaterials. Therefore, the recent development of composites of hybrid composites and polymers has been widely studied. In this study, we aimed to select the best scaffold of silk fibroin and β-TCP hybrid for bone tissue engineering. We fabricated three groups of scaffold such as SF (silk fibroin scaffold), GS (silk fibroin/small granule size of β-TCP scaffold) and GM (silk fibroin/medium granule size of β-TCP scaffold), and we compared the characteristics of each group. During characterization of the scaffold, we used scanning electron microscopy (SEM) and a Fourier transform infrared spectroscopy (FTIR) for structural analysis. We compared the physiological properties of the scaffold regarding the swelling ratio, water uptake and porosity. To evaluate the mechanical properties, we examined the compressive strength of the scaffold. During in vitro testing, we evaluated cell attachment and cell proliferation (CCK-8). Finally, we confirmed in vivo new bone regeneration from the implanted scaffolds using histological staining and micro-CT. From these evaluations, the fabricated scaffold demonstrated high porosity with good inter-pore connectivity, showed good biocompatibility and high compressive strength and modulus. In particular, the present study indicates that the GM scaffold using β-TCP accelerates new bone regeneration of implanted scaffolds. Accordingly, our scaffold is expected to act a useful application in the field of bone tissue engineering. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 1779-1787, 2016. PMID:26999521

  5. Indirect solid free form fabrication of local and global porous, biomimetic and composite 3D polymer-ceramic scaffolds.

    PubMed

    Taboas, J M; Maddox, R D; Krebsbach, P H; Hollister, S J

    2003-01-01

    Precise control over scaffold material, porosity, and internal pore architecture is essential for tissue engineering. By coupling solid free form (SFF) manufacturing with conventional sponge scaffold fabrication procedures, we have developed methods for casting scaffolds that contain designed and controlled locally porous and globally porous internal architectures. These methods are compatible with numerous bioresorbable and non-resorbable polymers, ceramics, and biologic materials. Phase separation, emulsion-solvent diffusion, and porogen leaching were used to create poly(L)lactide (PLA) scaffolds containing both computationally designed global pores (500, 600, or 800 microm wide channels) and solvent fashioned local pores (50-100 microm wide voids or 5-10 microm length plates). Globally porous PLA and polyglycolide/PLA discrete composites were made using melt processing. Biphasic scaffolds with mechanically interdigitated PLA and sintered hydroxyapatite regions were fabricated with 500 and 600 microm wide global pores. PLA scaffolds with complex internal architectures that mimicked human trabecular bone were produced. Our indirect fabrication using casting in SFF molds provided enhanced control over scaffold shape, material, porosity and pore architecture, including size, geometry, orientation, branching, and interconnectivity. These scaffolds that contain concurrent local and global pores, discrete material regions, and biomimetic internal architectures may prove valuable for multi-tissue and structural tissue interface engineering. PMID:12417192

  6. Gas anti-solvent precipitation assisted salt leaching for generation of micro- and nano-porous wall in bio-polymeric 3D scaffolds.

    PubMed

    Flaibani, Marina; Elvassore, Nicola

    2012-08-01

    The mass transport through biocompatible and biodegradable polymeric 3D porous scaffolds may be depleted by non-porous impermeable internal walls. As consequence the concentration of metabolites and growth factors within the scaffold may be heterogeneous leading to different cell fate depending on spatial cell location, and in some cases it may compromise cell survival. In this work, we fabricated polymeric scaffolds with micro- and nano-scale porosity by developing a new technique that couples two conventional scaffold production methods: solvent casting-salt leaching and gas antisolvent precipitation. 10-15 w/w solutions of a hyaluronic benzyl esters (HYAFF11) and poly-(lactic acid) (PLA) were used to fill packed beds of 0.177-0.425 mm NaCl crystals. The polymer precipitation in micro and nano-porous structures between the salt crystals was induced by high-pressure gas, then its flushing extracted the residual solvent. The salt was removed by water-wash. Morphological analysis by scanning electron microscopy showed a uniform porosity (~70%) and a high interconnectivity between porous. The polymeric walls were porous themselves counting for 30% of the total porosity. This wall porosity did not lead to a remarkable change in compressive modulus, deformation, and rupture pressure. Scaffold biocompatibility was tested with murine muscle cell line C2C12 for 4 and 7 days. Viability analysis and histology showed that micro- and nano-porous scaffolds are biocompatible and suitable for 3D cell culture promoting cell adhesion on the polymeric wall and allowing their proliferation in layers. Micro- and nano-scale porosities enhance cell migration and growth in the inner part of the scaffold.

  7. Gas anti-solvent precipitation assisted salt leaching for generation of micro- and nano-porous wall in bio-polymeric 3D scaffolds.

    PubMed

    Flaibani, Marina; Elvassore, Nicola

    2012-08-01

    The mass transport through biocompatible and biodegradable polymeric 3D porous scaffolds may be depleted by non-porous impermeable internal walls. As consequence the concentration of metabolites and growth factors within the scaffold may be heterogeneous leading to different cell fate depending on spatial cell location, and in some cases it may compromise cell survival. In this work, we fabricated polymeric scaffolds with micro- and nano-scale porosity by developing a new technique that couples two conventional scaffold production methods: solvent casting-salt leaching and gas antisolvent precipitation. 10-15 w/w solutions of a hyaluronic benzyl esters (HYAFF11) and poly-(lactic acid) (PLA) were used to fill packed beds of 0.177-0.425 mm NaCl crystals. The polymer precipitation in micro and nano-porous structures between the salt crystals was induced by high-pressure gas, then its flushing extracted the residual solvent. The salt was removed by water-wash. Morphological analysis by scanning electron microscopy showed a uniform porosity (~70%) and a high interconnectivity between porous. The polymeric walls were porous themselves counting for 30% of the total porosity. This wall porosity did not lead to a remarkable change in compressive modulus, deformation, and rupture pressure. Scaffold biocompatibility was tested with murine muscle cell line C2C12 for 4 and 7 days. Viability analysis and histology showed that micro- and nano-porous scaffolds are biocompatible and suitable for 3D cell culture promoting cell adhesion on the polymeric wall and allowing their proliferation in layers. Micro- and nano-scale porosities enhance cell migration and growth in the inner part of the scaffold. PMID:24364970

  8. Biodegradable HA-PLA 3-D porous scaffolds: effect of nano-sized filler content on scaffold properties.

    PubMed

    Kothapalli, Chandrasekhar R; Shaw, Montgomery T; Wei, Mei

    2005-11-01

    Scaffolds comprising poly(lactic acid) and nano-hydroxyapatite (HA) were prepared using the solvent-casting/salt-leaching technique. NaCl was used as the leaching agent. Nano-sized HA was synthesized by a hydrothermal method at 170 degrees C and autogenous pressure. High-resolution TEM imaging revealed that the HA particles were ellipsoidal-shaped with needle-like morphologies. The particles had an average size of approximately 25 nm in width and 150 nm in length with aspect ratios ranging from 6 to 8. As the HA content increased in the scaffold from 0 to 50 wt%, the compression modulus of the scaffolds increased from 4.72+/-1.2 to 9.87+/-1.8 MPa, while the yield strength from 0.29+/-0.03 to 0.44+/-0.01 MPa. Such polymeric scaffolds should be suitable materials for non-load sharing tissue-engineering applications. PMID:16701846

  9. Hybrid Macro-Porous Titanium Ornamented by Degradable 3D Gel/nHA Micro-Scaffolds for Bone Tissue Regeneration

    PubMed Central

    Yin, Bo; Ma, Pei; Chen, Jun; Wang, Hai; Wu, Gui; Li, Bo; Li, Qiang; Huang, Zhifeng; Qiu, Guixing; Wu, Zhihong

    2016-01-01

    Porous titanium is a kind of promising material for bone substitution, while its bio-inert property results in demand of modifications to improve the osteointegration capacity. In this study, gelatin (Gel) and nano-hydroxyapatite (nHA) were used to construct 3D micro-scaffolds in the pores of porous titanium in the ratios of Gel:nHA = 1:0, Gel:nHA = 1:1, and Gel:nHA = 1:3, respectively. Cell attachment and proliferation, and gene and protein expression levels of osteogenic markers were evaluated in MC3T3-E1 cells, followed by bone regeneration assessment in a rabbit radius defect model. All hybrid scaffolds with different composition ratio were found to have significant promotional effects in cell adhesion, proliferation and differentiation, in which the group with Gel:nHA = 1:1 showed the best performance in vitro, as well as the most bone regeneration volume in vivo. This 3D micro-scaffolds modification may be an innovative method for porous titanium ornamentation and shows potential application values in clinic. PMID:27092492

  10. Hybrid Macro-Porous Titanium Ornamented by Degradable 3D Gel/nHA Micro-Scaffolds for Bone Tissue Regeneration.

    PubMed

    Yin, Bo; Ma, Pei; Chen, Jun; Wang, Hai; Wu, Gui; Li, Bo; Li, Qiang; Huang, Zhifeng; Qiu, Guixing; Wu, Zhihong

    2016-04-15

    Porous titanium is a kind of promising material for bone substitution, while its bio-inert property results in demand of modifications to improve the osteointegration capacity. In this study, gelatin (Gel) and nano-hydroxyapatite (nHA) were used to construct 3D micro-scaffolds in the pores of porous titanium in the ratios of Gel:nHA = 1:0, Gel:nHA = 1:1, and Gel:nHA = 1:3, respectively. Cell attachment and proliferation, and gene and protein expression levels of osteogenic markers were evaluated in MC3T3-E1 cells, followed by bone regeneration assessment in a rabbit radius defect model. All hybrid scaffolds with different composition ratio were found to have significant promotional effects in cell adhesion, proliferation and differentiation, in which the group with Gel:nHA = 1:1 showed the best performance in vitro, as well as the most bone regeneration volume in vivo. This 3D micro-scaffolds modification may be an innovative method for porous titanium ornamentation and shows potential application values in clinic.

  11. Pore size and LbL chitosan coating influence mesenchymal stem cell in vitro fibrosis and biomineralization in 3D porous poly(epsilon-caprolactone) scaffolds.

    PubMed

    Mehr, Nima Ghavidel; Li, Xian; Chen, Gaoping; Favis, Basil D; Hoemann, Caroline D

    2015-07-01

    Poly(epsilon-caprolactone) (PCL) is a hydrophobic bioplastic under development for bone tissue engineering applications. Limited information is available on the role of internal geometry and cell-surface attachment on osseous integration potential. We tested the hypothesis that human bone marrow mesenchymal stem cells (MSCs) deposit more mineral inside porous 3D PCL scaffolds with fully interconnected 84 or 141 µm pores, when the surfaces are coated with chitosan via Layer-by-Layer (LbL)-deposited polyelectrolytes. Freshly trypsinized MSCs were seeded on PCL 3D cylinders using a novel static cold seeding method in 2% serum to optimally populate all depths of the scaffold discs, followed by 10 days of culture in proliferation medium and 21 additional days in osteogenic medium. MSCs were observed by SEM and histology to spread faster and to proliferate more on chitosan-coated pore surfaces. Most pores, with or without chitosan, became filled by collagen networks sparsely populated with fibroblast-like cells. After 21 days of culture in osteogenic medium, sporadic matrix mineralization was detected histologically and by micro-CT in highly cellular surface layers that enveloped all scaffolds and in cell aggregates in 141 µm pores near the edges. LbL-chitosan promoted punctate mineral deposition on the surfaces of 84 µm pores (p < 0.05 vs. PCL-only) but not the 141 µm pores. This study revealed that LbL-chitosan coatings are sufficient to promote MSC attachment to PCL but only enhance mineral formation in 84 µm pores, suggesting a potential inhibitory role for MSC-derived fibroblasts in osteoblast terminal differentiation. PMID:25504184

  12. Fabrication of 3D porous silk scaffolds by particulate (salt/sucrose) leaching for bone tissue reconstruction.

    PubMed

    Park, Hyun Jung; Lee, Ok Joo; Lee, Min Chae; Moon, Bo Mi; Ju, Hyung Woo; Lee, Jung min; Kim, Jung-Ho; Kim, Dong Wook; Park, Chan Hum

    2015-01-01

    Silk fibroin is a biomaterial being actively studied in the field of bone tissue engineering. In this study, we aimed to select the best strategy for bone reconstruction on scaffolds by changing various conditions. We compared the characteristics of each scaffold via structural analysis using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), the swelling ratio, water uptake, porosity, compressive strength, cell infiltration and cell viability (CCK-8). The scaffolds had high porosity with good inter pore connectivity and showed high compressive strength and modulus. In addition, to confirm bone reconstruction, animal studies were conducted in which samples were implanted in rat calvaria and investigated by micro-CT scans. In conclusion, the presented study indicates that using sucrose produces scaffolds showing better pore interconnectivity and cell infiltration than scaffolds made by using a salt process. In addition, in vivo experiments showed that hydroxyapatite accelerates bone reconstruction on implanted scaffolds. Accordingly, our scaffold will be expected to have a useful application in bone reconstruction.

  13. 3D Porous Calcium-Alginate Scaffolds Cell Culture System Improved Human Osteoblast Cell Clusters for Cell Therapy

    PubMed Central

    Chen, Ching-Yun; Ke, Cherng-Jyh; Yen, Ko-Chung; Hsieh, Hui-Chen; Sun, Jui-Sheng; Lin, Feng-Huei

    2015-01-01

    Age-related orthopedic disorders and bone defects have become a critical public health issue, and cell-based therapy is potentially a novel solution for issues surrounding bone tissue engineering and regenerative medicine. Long-term cultures of primary bone cells exhibit phenotypic and functional degeneration; therefore, culturing cells or tissues suitable for clinical use remain a challenge. A platform consisting of human osteoblasts (hOBs), calcium-alginate (Ca-Alginate) scaffolds, and a self-made bioreactor system was established for autologous transplantation of human osteoblast cell clusters. The Ca-Alginate scaffold facilitated the growth and differentiation of human bone cell clusters, and the functionally-closed process bioreactor system supplied the soluble nutrients and osteogenic signals required to maintain the cell viability. This system preserved the proliferative ability of cells and cell viability and up-regulated bone-related gene expression and biological apatite crystals formation. The bone-like tissue generated could be extracted by removal of calcium ions via ethylenediaminetetraacetic acid (EDTA) chelation, and exhibited a size suitable for injection. The described strategy could be used in therapeutic application and opens new avenues for surgical interventions to correct skeletal defects. PMID:25825603

  14. 3D-printed scaffolds based on PLA/HA nanocomposites for trabecular bone reconstruction

    NASA Astrophysics Data System (ADS)

    Niaza, K. V.; Senatov, F. S.; Kaloshkin, S. D.; Maksimkin, A. V.; Chukov, D. I.

    2016-08-01

    In the present work porous PLA scaffolds filled with micro- and nano- HA were studied. Both composites with micro- and nano-HA were obtained by extrusion in the same conditions. Scaffolds were obtained by 3D-printing by fused filament fabrication method. Structure of porous scaffolds was pre-modeled by computer software. Compression and three - point flexural tests were used to study mechanical properties of the scaffolds.

  15. 3D printing of novel osteochondral scaffolds with graded microstructure.

    PubMed

    Nowicki, Margaret A; Castro, Nathan J; Plesniak, Michael W; Zhang, Lijie Grace

    2016-10-14

    Osteochondral tissue has a complex graded structure where biological, physiological, and mechanical properties vary significantly over the full thickness spanning from the subchondral bone region beneath the joint surface to the hyaline cartilage region at the joint surface. This presents a significant challenge for tissue-engineered structures addressing osteochondral defects. Fused deposition modeling (FDM) 3D bioprinters present a unique solution to this problem. The objective of this study is to use FDM-based 3D bioprinting and nanocrystalline hydroxyapatite for improved bone marrow human mesenchymal stem cell (hMSC) adhesion, growth, and osteochondral differentiation. FDM printing parameters can be tuned through computer aided design and computer numerical control software to manipulate scaffold geometries in ways that are beneficial to mechanical performance without hindering cellular behavior. Additionally, the ability to fine-tune 3D printed scaffolds increases further through our investment casting procedure which facilitates the inclusion of nanoparticles with biochemical factors to further elicit desired hMSC differentiation. For this study, FDM was used to print investment-casting molds innovatively designed with varied pore distribution over the full thickness of the scaffold. The mechanical and biological impacts of the varied pore distributions were compared and evaluated to determine the benefits of this physical manipulation. The results indicate that both mechanical properties and cell performance improve in the graded pore structures when compared to homogeneously distributed porous and non-porous structures. Differentiation results indicated successful osteogenic and chondrogenic manipulation in engineered scaffolds. PMID:27606933

  16. 3D printing of novel osteochondral scaffolds with graded microstructure

    NASA Astrophysics Data System (ADS)

    Nowicki, Margaret A.; Castro, Nathan J.; Plesniak, Michael W.; Zhang, Lijie Grace

    2016-10-01

    Osteochondral tissue has a complex graded structure where biological, physiological, and mechanical properties vary significantly over the full thickness spanning from the subchondral bone region beneath the joint surface to the hyaline cartilage region at the joint surface. This presents a significant challenge for tissue-engineered structures addressing osteochondral defects. Fused deposition modeling (FDM) 3D bioprinters present a unique solution to this problem. The objective of this study is to use FDM-based 3D bioprinting and nanocrystalline hydroxyapatite for improved bone marrow human mesenchymal stem cell (hMSC) adhesion, growth, and osteochondral differentiation. FDM printing parameters can be tuned through computer aided design and computer numerical control software to manipulate scaffold geometries in ways that are beneficial to mechanical performance without hindering cellular behavior. Additionally, the ability to fine-tune 3D printed scaffolds increases further through our investment casting procedure which facilitates the inclusion of nanoparticles with biochemical factors to further elicit desired hMSC differentiation. For this study, FDM was used to print investment-casting molds innovatively designed with varied pore distribution over the full thickness of the scaffold. The mechanical and biological impacts of the varied pore distributions were compared and evaluated to determine the benefits of this physical manipulation. The results indicate that both mechanical properties and cell performance improve in the graded pore structures when compared to homogeneously distributed porous and non-porous structures. Differentiation results indicated successful osteogenic and chondrogenic manipulation in engineered scaffolds.

  17. 3D printing of novel osteochondral scaffolds with graded microstructure.

    PubMed

    Nowicki, Margaret A; Castro, Nathan J; Plesniak, Michael W; Zhang, Lijie Grace

    2016-10-14

    Osteochondral tissue has a complex graded structure where biological, physiological, and mechanical properties vary significantly over the full thickness spanning from the subchondral bone region beneath the joint surface to the hyaline cartilage region at the joint surface. This presents a significant challenge for tissue-engineered structures addressing osteochondral defects. Fused deposition modeling (FDM) 3D bioprinters present a unique solution to this problem. The objective of this study is to use FDM-based 3D bioprinting and nanocrystalline hydroxyapatite for improved bone marrow human mesenchymal stem cell (hMSC) adhesion, growth, and osteochondral differentiation. FDM printing parameters can be tuned through computer aided design and computer numerical control software to manipulate scaffold geometries in ways that are beneficial to mechanical performance without hindering cellular behavior. Additionally, the ability to fine-tune 3D printed scaffolds increases further through our investment casting procedure which facilitates the inclusion of nanoparticles with biochemical factors to further elicit desired hMSC differentiation. For this study, FDM was used to print investment-casting molds innovatively designed with varied pore distribution over the full thickness of the scaffold. The mechanical and biological impacts of the varied pore distributions were compared and evaluated to determine the benefits of this physical manipulation. The results indicate that both mechanical properties and cell performance improve in the graded pore structures when compared to homogeneously distributed porous and non-porous structures. Differentiation results indicated successful osteogenic and chondrogenic manipulation in engineered scaffolds.

  18. Cell colonization in degradable 3D porous matrices

    PubMed Central

    Lawrence, Benjamin J

    2008-01-01

    Cell colonization is an important in a wide variety of biological processes and applications including vascularization, wound healing, tissue engineering, stem cell differentiation and biosensors. During colonization porous 3D structures are used to support and guide the ingrowth of cells into the matrix. In this review, we summarize our understanding of various factors affecting cell colonization in three-dimensional environment. The structural, biological and degradation properties of the matrix all play key roles during colonization. Further, specific scaffold properties such as porosity, pore size, fiber thickness, topography and scaffold stiffness as well as important cell material interactions such as cell adhesion and mechanotransduction also influence colonization. PMID:19262124

  19. Enhancement of neurite outgrowth in neuron cancer stem cells by growth on 3-D collagen scaffolds

    SciTech Connect

    Chen, Chih-Hao; Kuo, Shyh Ming; Liu, Guei-Sheung; Chen, Wan-Nan U.; Chuang, Chin-Wen; Liu, Li-Feng

    2012-11-09

    Highlights: Black-Right-Pointing-Pointer Neuron cancer stem cells (NCSCs) behave high multiply of growth on collagen scaffold. Black-Right-Pointing-Pointer Enhancement of NCSCs neurite outgrowth on porous collagen scaffold. Black-Right-Pointing-Pointer 3-D collagen culture of NCSCs shows an advance differentiation than 2-D culture. -- Abstract: Collagen is one component of the extracellular matrix that has been widely used for constructive remodeling to facilitate cell growth and differentiation. The 3-D distribution and growth of cells within the porous scaffold suggest a clinical significance for nerve tissue engineering. In the current study, we investigated proliferation and differentiation of neuron cancer stem cells (NCSCs) on a 3-D porous collagen scaffold that mimics the natural extracellular matrix. We first generated green fluorescence protein (GFP) expressing NCSCs using a lentiviral system to instantly monitor the transitions of morphological changes during growth on the 3-D scaffold. We found that proliferation of GFP-NCSCs increased, and a single cell mass rapidly grew with unrestricted expansion between days 3 and 9 in culture. Moreover, immunostaining with neuronal nuclei (NeuN) revealed that NCSCs grown on the 3-D collagen scaffold significantly enhanced neurite outgrowth. Our findings confirmed that the 80 {mu}m porous collagen scaffold could enhance attachment, viability and differentiation of the cancer neural stem cells. This result could provide a new application for nerve tissue engineering and nerve regeneration.

  20. Characterisation of the surface structure of 3D printed scaffolds for cell infiltration and surgical suturing.

    PubMed

    Ruiz-Cantu, Laura; Gleadall, Andrew; Faris, Callum; Segal, Joel; Shakesheff, Kevin; Yang, Jing

    2016-03-01

    3D printing is of great interest for tissue engineering scaffolds due to the ability to form complex geometries and control internal structures, including porosity and pore size. The porous structure of scaffolds plays an important role in cell ingrowth and nutrition infusion. Although the internal porosity and pore size of 3D printed scaffolds have been frequently studied, the surface porosity and pore size, which are critical for cell infiltration and mass transport, have not been investigated. The surface geometry can differ considerably from the internal scaffold structure depending on the 3D printing process. It is vital to be able to control the surface geometry of scaffolds as well as the internal structure to fabricate optimal architectures. This work presents a method to control the surface porosity and pore size of 3D printed scaffolds. Six scaffold designs have been printed with surface porosities ranging from 3% to 21%. We have characterised the overall scaffold porosity and surface porosity using optical microscopy and microCT. It has been found that surface porosity has a significant impact on cell infiltration and proliferation. In addition, the porosity of the surface has been found to have an effect on mechanical properties and on the forces required to penetrate the scaffold with a surgical suturing needle. To the authors' knowledge, this study is the first to investigate the surface geometry of extrusion-based 3D printed scaffolds and demonstrates the importance of surface geometry in cell infiltration and clinical manipulation. PMID:26930179

  1. Characterisation of the surface structure of 3D printed scaffolds for cell infiltration and surgical suturing.

    PubMed

    Ruiz-Cantu, Laura; Gleadall, Andrew; Faris, Callum; Segal, Joel; Shakesheff, Kevin; Yang, Jing

    2016-03-01

    3D printing is of great interest for tissue engineering scaffolds due to the ability to form complex geometries and control internal structures, including porosity and pore size. The porous structure of scaffolds plays an important role in cell ingrowth and nutrition infusion. Although the internal porosity and pore size of 3D printed scaffolds have been frequently studied, the surface porosity and pore size, which are critical for cell infiltration and mass transport, have not been investigated. The surface geometry can differ considerably from the internal scaffold structure depending on the 3D printing process. It is vital to be able to control the surface geometry of scaffolds as well as the internal structure to fabricate optimal architectures. This work presents a method to control the surface porosity and pore size of 3D printed scaffolds. Six scaffold designs have been printed with surface porosities ranging from 3% to 21%. We have characterised the overall scaffold porosity and surface porosity using optical microscopy and microCT. It has been found that surface porosity has a significant impact on cell infiltration and proliferation. In addition, the porosity of the surface has been found to have an effect on mechanical properties and on the forces required to penetrate the scaffold with a surgical suturing needle. To the authors' knowledge, this study is the first to investigate the surface geometry of extrusion-based 3D printed scaffolds and demonstrates the importance of surface geometry in cell infiltration and clinical manipulation.

  2. Superabsorbent 3D Scaffold Based on Electrospun Nanofibers for Cartilage Tissue Engineering.

    PubMed

    Chen, Weiming; Chen, Shuai; Morsi, Yosry; El-Hamshary, Hany; El-Newhy, Mohamed; Fan, Cunyi; Mo, Xiumei

    2016-09-21

    Electrospun nanofibers have been used for various biomedical applications. However, electrospinning commonly produces two-dimensional (2D) membranes, which limits the application of nanofibers for the 3D tissue engineering scaffold. In the present study, a porous 3D scaffold (3DS-1) based on electrospun gelatin/PLA nanofibers has been prepared for cartilage tissue regeneration. To further improve the repairing effect of cartilage, a modified scaffold (3DS-2) cross-linked with hyaluronic acid (HA) was also successfully fabricated. The nanofibrous structure, water absorption, and compressive mechanical properties of 3D scaffold were studied. Chondrocytes were cultured on 3D scaffold, and their viability and morphology were examined. 3D scaffolds were also subjected to an in vivo cartilage regeneration study on rabbits using an articular cartilage injury model. The results indicated that 3DS-1 and 3DS-2 exhibited superabsorbent property and excellent cytocompatibility. Both these scaffolds present elastic property in the wet state. An in vivo study showed that 3DS-2 could enhance the repair of cartilage. The present 3D nanofibrous scaffold (3DS-2) would be promising for cartilage tissue engineering application. PMID:27559926

  3. Superabsorbent 3D Scaffold Based on Electrospun Nanofibers for Cartilage Tissue Engineering.

    PubMed

    Chen, Weiming; Chen, Shuai; Morsi, Yosry; El-Hamshary, Hany; El-Newhy, Mohamed; Fan, Cunyi; Mo, Xiumei

    2016-09-21

    Electrospun nanofibers have been used for various biomedical applications. However, electrospinning commonly produces two-dimensional (2D) membranes, which limits the application of nanofibers for the 3D tissue engineering scaffold. In the present study, a porous 3D scaffold (3DS-1) based on electrospun gelatin/PLA nanofibers has been prepared for cartilage tissue regeneration. To further improve the repairing effect of cartilage, a modified scaffold (3DS-2) cross-linked with hyaluronic acid (HA) was also successfully fabricated. The nanofibrous structure, water absorption, and compressive mechanical properties of 3D scaffold were studied. Chondrocytes were cultured on 3D scaffold, and their viability and morphology were examined. 3D scaffolds were also subjected to an in vivo cartilage regeneration study on rabbits using an articular cartilage injury model. The results indicated that 3DS-1 and 3DS-2 exhibited superabsorbent property and excellent cytocompatibility. Both these scaffolds present elastic property in the wet state. An in vivo study showed that 3DS-2 could enhance the repair of cartilage. The present 3D nanofibrous scaffold (3DS-2) would be promising for cartilage tissue engineering application.

  4. Development of 3D PPF/DEF scaffolds using micro-stereolithography and surface modification.

    PubMed

    Lan, Phung Xuan; Lee, Jin Woo; Seol, Young-Joon; Cho, Dong-Woo

    2009-01-01

    Poly(propylene fumarate) (PPF) is an ultraviolet-curable and biodegradable polymer with potential applications for bone regeneration. In this study, we designed and fabricated three-dimensional (3D) porous scaffolds based on a PPF polymer network using micro-stereolithography (MSTL). The 3D scaffold was well fabricated with a highly interconnected porous structure and porosity of 65%. These results provide a new scaffold fabrication method for tissue engineering. Surface modification is a commonly used and effective method for improving the surface characteristics of biomaterials without altering their bulk properties that avoids the expense and long time associated with the development of new biomaterials. Therefore, we examined surface modification of 3D scaffolds by applying accelerated biomimetic apatite and arginine-glycine-aspartic acid (RGD) peptide coating to promote cell behavior. The apatite coating uniformly covered the scaffold surface after immersion for 24 h in 5-fold simulated body fluid (5SBF) and then the RGD peptide was applied. Finally, the coated 3D scaffolds were seeded with MC3T3-E1 pre-osteoblasts and their biologic properties were evaluated using an MTS assay and histologic staining. We found that 3D PPF/diethyl fumarate (DEF) scaffolds fabricated with MSTL and biomimetic apatite coating can be potentially used in bone tissue engineering.

  5. 3D braid scaffolds for regeneration of articular cartilage.

    PubMed

    Ahn, Hyunchul; Kim, Kyoung Ju; Park, Sook Young; Huh, Jeong Eun; Kim, Hyun Jeong; Yu, Woong-Ryeol

    2014-06-01

    Regenerating articular cartilage in vivo from cultured chondrocytes requires that the cells be cultured and implanted within a biocompatible, biodegradable scaffold. Such scaffolds must be mechanically stable; otherwise chondrocytes would not be supported and patients would experience severe pain. Here we report a new 3D braid scaffold that matches the anisotropic (gradient) mechanical properties of natural articular cartilage and is permissive to cell cultivation. To design an optimal structure, the scaffold unit cell was mathematically modeled and imported into finite element analysis. Based on this analysis, a 3D braid structure with gradient axial yarn distribution was designed and manufactured using a custom-built braiding machine. The mechanical properties of the 3D braid scaffold were evaluated and compared with simulated results, demonstrating that a multi-scale approach consisting of unit cell modeling and continuum analysis facilitates design of scaffolds that meet the requirements for mechanical compatibility with tissues. PMID:24556323

  6. Sphere-shaped nano-hydroxyapatite/chitosan/gelatin 3D porous scaffolds increase proliferation and osteogenic differentiation of human induced pluripotent stem cells from gingival fibroblasts.

    PubMed

    Ji, Jun; Tong, Xin; Huang, Xiaofeng; Wang, Tiancong; Lin, Zitong; Cao, Yazhou; Zhang, Junfeng; Dong, Lei; Qin, Haiyan; Hu, Qingang

    2015-08-01

    Hydroxyapatite (HA) is an important component of human bone and bone tissue engineering scaffolds. A plethora of bone tissue engineering scaffolds have been synthesized so far, including nano-HA/chitosan/gelatin (nHA/CG) scaffolds; and for seeding cells, stem cells, especially induced pluripotent stem cells (iPSCs), have been a promising cell source for bone tissue engineering recently. However, the influence of different HA nano-particle morphologies on the osteogenic differentiation of human iPSCs (hiPSCs) from human gingival fibroblasts (hGFs) is unknown. The purpose of this study was to investigate the osteogenic differentiation of hiPSCs from hGFs seeded on nHA/CG scaffolds with 2 shapes (rod and sphere) of nHA particles. Firstly, hGFs isolated from discarded normal gingival tissues were reprogrammed into hiPSCs. Secondly, hiPSCs were seeded on rod-like nHA/CG (rod-nHA/CG) and sphere-shaped nHA/CG (sphere-nHA/CG) scaffolds respectively and then cell/scaffold complexes were cultured in vitro. Scanning electron microscope, hematoxyline and eosin (HE) staining, Masson's staining, and quantitative real-time polymerase chain reaction techniques were used to examine hiPSC morphology, proliferation, and differentiation on rod-nHA/CG and sphere-nHA/CG scaffolds. Finally, hiPSCs composited with 2 kinds of nHA/CG were transplanted in vivo in a subcutaneous implantation model for 12 weeks; pure scaffolds were also transplanted as a blank control. HE, Masson's, and immunohistochemistry staining were applied to detect new bone regeneration ability. The results showed that sphere-nHA/CG significantly increased hiPSCs from hGF proliferation and osteogenic differentiation in vitro. hiPSCs and sphere-nHA/CG composities generated large bone, whereas hiPSCs and rod-nHA/CG composities produced tiny bone in vivo. Moreover, pure scaffolds without cells almost produced no bone. In conclusion, our work provided a potential innovative bone tissue engineering approach using

  7. Apple Derived Cellulose Scaffolds for 3D Mammalian Cell Culture

    PubMed Central

    Modulevsky, Daniel J.; Lefebvre, Cory; Haase, Kristina; Al-Rekabi, Zeinab; Pelling, Andrew E.

    2014-01-01

    There are numerous approaches for producing natural and synthetic 3D scaffolds that support the proliferation of mammalian cells. 3D scaffolds better represent the natural cellular microenvironment and have many potential applications in vitro and in vivo. Here, we demonstrate that 3D cellulose scaffolds produced by decellularizing apple hypanthium tissue can be employed for in vitro 3D culture of NIH3T3 fibroblasts, mouse C2C12 muscle myoblasts and human HeLa epithelial cells. We show that these cells can adhere, invade and proliferate in the cellulose scaffolds. In addition, biochemical functionalization or chemical cross-linking can be employed to control the surface biochemistry and/or mechanical properties of the scaffold. The cells retain high viability even after 12 continuous weeks of culture and can achieve cell densities comparable with other natural and synthetic scaffold materials. Apple derived cellulose scaffolds are easily produced, inexpensive and originate from a renewable source. Taken together, these results demonstrate that naturally derived cellulose scaffolds offer a complementary approach to existing techniques for the in vitro culture of mammalian cells in a 3D environment. PMID:24842603

  8. 3D Microperiodic Hydrogel Scaffolds for Robust Neuronal Cultures

    PubMed Central

    Hanson Shepherd, Jennifer N.; Parker, Sara T.; Shepherd, Robert F.; Gillette, Martha U.; Lewis, Jennifer A.; Nuzzo, Ralph G.

    2011-01-01

    Three-dimensional (3D) microperiodic scaffolds of poly(2-hydroxyethyl methacrylate) (pHEMA) have been fabricated by direct-write assembly of a photopolymerizable hydrogel ink. The ink is initially composed of physically entangled pHEMA chains dissolved in a solution of HEMA monomer, comonomer, photoinitiator and water. Upon printing 3D scaffolds of varying architecture, the ink filaments are exposed to UV light, where they are transformed into an interpenetrating hydrogel network of chemically cross-linked and physically entangled pHEMA chains. These 3D microperiodic scaffolds are rendered growth compliant for primary rat hippocampal neurons by absorption of polylysine. Neuronal cells thrive on these scaffolds, forming differentiated, intricately branched networks. Confocal laser scanning microscopy reveals that both cell distribution and extent of neuronal process alignment depend upon scaffold architecture. This work provides an important step forward in the creation of suitable platforms for in vitro study of sensitive cell types. PMID:21709750

  9. Porous ceramic scaffolds with complex architectures

    SciTech Connect

    Saiz, Eduardo; Munch, Etienne; Franco, Jaime; Deville, Sylvain; Hunger, Phillip; Saiz, Eduardo; Tomsia, Antoni P.

    2008-03-15

    This work compares two novel techniques for the fabrication of ceramic scaffolds for bone tissue engineering with complex porosity: robocasting and freeze casting. Both techniques are based on the preparation of concentrated ceramic suspensions with suitable properties for the process. In robocasting, the computer-guided deposition of the suspensions is used to build porous materials with designed three dimensional (3-D) geometries and microstructures. Freeze casting uses ice crystals as a template to form porous lamellar ceramic materials. Preliminary results on the compressive strengths of the materials are also reported.

  10. Nano/macro porous bioactive glass scaffold

    NASA Astrophysics Data System (ADS)

    Wang, Shaojie

    Bioactive glass (BG) and ceramics have been widely studied and developed as implants to replace hard tissues of the musculo-skeletal system, such as bones and teeth. Recently, instead of using bulk materials, which usually do not degrade rapidly enough and may remain in the human body for a long time, the idea of bioscaffold for tissue regeneration has generated much interest. An ideal bioscaffold is a porous material that would not only provide a three-dimensional structure for the regeneration of natural tissue, but also degrade gradually and, eventually be replaced by the natural tissue completely. Among various material choices the nano-macro dual porous BG appears as the most promising candidate for bioscaffold applications. Here macropores facilitate tissue growth while nanopores control degradation and enhance cell response. The surface area, which controls the degradation of scaffold can also be tuned by changing the nanopore size. However, fabrication of such 3D structure with desirable nano and macro pores has remained challenging. In this dissertation, sol-gel process combined with spinodal decomposition or polymer sponge replication method has been developed to fabricate the nano-macro porous BG scaffolds. Macropores up to 100microm are created by freezing polymer induced spinodal structure through sol-gel transition, while larger macropores (>200um) of predetermined size are obtained by the polymer sponge replication technique. The size of nanopores, which are inherent to the sol-gel method of glass fabrication, has been tailored using several approaches: Before gel point, small nanopores are generated using acid catalyst that leads to weakly-branched polymer-like network. On the other hand, larger nanopores are created with the base-catalyzed gel with highly-branched cluster-like structure. After the gel point, the nanostructure can be further modified by manipulating the sintering temperature and/or the ammonia concentration used in the solvent

  11. Effect of sterilization on structural and material properties of 3-D silk fibroin scaffolds.

    PubMed

    Hofmann, Sandra; Stok, Kathryn S; Kohler, Thomas; Meinel, Anne J; Müller, Ralph

    2014-01-01

    The development of porous scaffolds for tissue engineering applications requires the careful choice of properties, as these influence cell adhesion, proliferation and differentiation. Sterilization of scaffolds is a prerequisite for in vitro culture as well as for subsequent in vivo implantation. The variety of methods used to provide sterility is as diverse as the possible effects they can have on the structural and material properties of the three-dimensional (3-D) porous structure, especially in polymeric or proteinous scaffold materials. Silk fibroin (SF) has previously been demonstrated to offer exceptional benefits over conventional synthetic and natural biomaterials in generating scaffolds for tissue replacements. This study sought to determine the effect of sterilization methods, such as autoclaving, heat-, ethylene oxide-, ethanol- or antibiotic-antimycotic treatment, on porous 3-D SF scaffolds. In terms of scaffold morphology, topography, crystallinity and short-term cell viability, the different sterilization methods showed only few effects. Nevertheless, mechanical properties were significantly decreased by a factor of two by all methods except for dry autoclaving, which seemed not to affect mechanical properties compared to the native control group. These data suggest that SF scaffolds are in general highly resistant to various sterilization treatments. Nevertheless, care should be taken if initial mechanical properties are of interest.

  12. Design, construction and mechanical testing of digital 3D anatomical data-based PCL-HA bone tissue engineering scaffold.

    PubMed

    Yao, Qingqiang; Wei, Bo; Guo, Yang; Jin, Chengzhe; Du, Xiaotao; Yan, Chao; Yan, Junwei; Hu, Wenhao; Xu, Yan; Zhou, Zhi; Wang, Yijin; Wang, Liming

    2015-01-01

    The study aims to investigate the techniques of design and construction of CT 3D reconstructional data-based polycaprolactone (PCL)-hydroxyapatite (HA) scaffold. Femoral and lumbar spinal specimens of eight male New Zealand white rabbits were performed CT and laser scanning data-based 3D printing scaffold processing using PCL-HA powder. Each group was performed eight scaffolds. The CAD-based 3D printed porous cylindrical stents were 16 piece × 3 groups, including the orthogonal scaffold, the Pozi-hole scaffold and the triangular hole scaffold. The gross forms, fiber scaffold diameters and porosities of the scaffolds were measured, and the mechanical testing was performed towards eight pieces of the three kinds of cylindrical scaffolds, respectively. The loading force, deformation, maximum-affordable pressure and deformation value were recorded. The pore-connection rate of each scaffold was 100 % within each group, there was no significant difference in the gross parameters and micro-structural parameters of each scaffold when compared with the design values (P > 0.05). There was no significant difference in the loading force, deformation and deformation value under the maximum-affordable pressure of the three different cylinder scaffolds when the load was above 320 N. The combination of CT and CAD reverse technology could accomplish the design and manufacturing of complex bone tissue engineering scaffolds, with no significant difference in the impacts of the microstructures towards the physical properties of different porous scaffolds under large load.

  13. 3D Printed Silicone-Hydrogel Scaffold with Enhanced Physicochemical Properties.

    PubMed

    Mohanty, Soumyaranjan; Alm, Martin; Hemmingsen, Mette; Dolatshahi-Pirouz, Alireza; Trifol, Jon; Thomsen, Peter; Dufva, Martin; Wolff, Anders; Emnéus, Jenny

    2016-04-11

    Scaffolds with multiple functionalities have attracted widespread attention in the field of tissue engineering due to their ability to control cell behavior through various cues, including mechanical, chemical, and electrical. Fabrication of such scaffolds from clinically approved materials is currently a huge challenge. The goal of this work was to fabricate a tissue engineering scaffold from clinically approved materials with the capability of delivering biomolecules and direct cell fate. We have used a simple 3D printing approach, that combines polymer casting with supercritical fluid technology to produce 3D interpenetrating polymer network (IPN) scaffold of silicone-poly(2-hydroxyethyl methacrylate)-co-poly(ethylene glycol) methyl ether acrylate (pHEMA-co-PEGMEA). The pHEMA-co-PEGMEA IPN materials were employed to support growth of human mesenchymal stem cells (hMSC), resulting in high cell viability and metabolic activity over a 3 weeks period. In addition, the IPN scaffolds support 3D tissue formation inside the porous scaffold with well spread cell morphology on the surface of the scaffold. As a proof of concept, sustained doxycycline (DOX) release from pHEMA-co-PEGMEA IPN was demonstrated and the biological activity of released drug from IPN was confirmed using a DOX regulated green fluorescent reporter (GFP) gene expression assay with HeLa cells. Given its unique mechanical and drug releasing characteristics, IPN scaffolds may be used for directing stem cell differentiation by releasing various chemicals from its hydrogel network.

  14. 3D Printed Silicone-Hydrogel Scaffold with Enhanced Physicochemical Properties.

    PubMed

    Mohanty, Soumyaranjan; Alm, Martin; Hemmingsen, Mette; Dolatshahi-Pirouz, Alireza; Trifol, Jon; Thomsen, Peter; Dufva, Martin; Wolff, Anders; Emnéus, Jenny

    2016-04-11

    Scaffolds with multiple functionalities have attracted widespread attention in the field of tissue engineering due to their ability to control cell behavior through various cues, including mechanical, chemical, and electrical. Fabrication of such scaffolds from clinically approved materials is currently a huge challenge. The goal of this work was to fabricate a tissue engineering scaffold from clinically approved materials with the capability of delivering biomolecules and direct cell fate. We have used a simple 3D printing approach, that combines polymer casting with supercritical fluid technology to produce 3D interpenetrating polymer network (IPN) scaffold of silicone-poly(2-hydroxyethyl methacrylate)-co-poly(ethylene glycol) methyl ether acrylate (pHEMA-co-PEGMEA). The pHEMA-co-PEGMEA IPN materials were employed to support growth of human mesenchymal stem cells (hMSC), resulting in high cell viability and metabolic activity over a 3 weeks period. In addition, the IPN scaffolds support 3D tissue formation inside the porous scaffold with well spread cell morphology on the surface of the scaffold. As a proof of concept, sustained doxycycline (DOX) release from pHEMA-co-PEGMEA IPN was demonstrated and the biological activity of released drug from IPN was confirmed using a DOX regulated green fluorescent reporter (GFP) gene expression assay with HeLa cells. Given its unique mechanical and drug releasing characteristics, IPN scaffolds may be used for directing stem cell differentiation by releasing various chemicals from its hydrogel network. PMID:26902925

  15. 3D Printing of Scaffolds for Tissue Regeneration Applications

    PubMed Central

    Do, Anh-Vu; Khorsand, Behnoush; Geary, Sean M.; Salem, Aliasger K.

    2015-01-01

    The current need for organ and tissue replacement, repair and regeneration for patients is continually growing such that supply is not meeting the high demand primarily due to a paucity of donors as well as biocompatibility issues that lead to immune rejection of the transplant. In an effort to overcome these drawbacks, scientists working in the field of tissue engineering and regenerative medicine have investigated the use of scaffolds as an alternative to transplantation. These scaffolds are designed to mimic the extracellular matrix (ECM) by providing structural support as well as promoting attachment, proliferation, and differentiation with the ultimate goal of yielding functional tissues or organs. Initial attempts at developing scaffolds were problematic and subsequently inspired a growing interest in 3D printing as a mode for generating scaffolds. Utilizing three-dimensional printing (3DP) technologies, ECM-like scaffolds can be produced with a high degree of complexity and precision, where fine details can be included at a micron level. In this review, we discuss the criteria for printing viable and functional scaffolds, scaffolding materials, and 3DP technologies used to print scaffolds for tissue engineering. A hybrid approach, employing both natural and synthetic materials, as well as multiple printing processes may be the key to yielding an ECM-like scaffold with high mechanical strength, porosity, interconnectivity, biocompatibility, biodegradability, and high processability. Creating such biofunctional scaffolds could potentially help to meet the demand by patients for tissues and organs without having to wait or rely on donors for transplantation. PMID:26097108

  16. Nanostructured thick 3D nanofibrous scaffold can induce bone.

    PubMed

    Eap, Sandy; Morand, David; Clauss, François; Huck, Olivier; Stoltz, Jean-François; Lutz, Jean-Christophe; Gottenberg, Jacques-Eric; Benkirane-Jessel, Nadia; Keller, Laetitia; Fioretti, Florence

    2015-01-01

    Designing unique nanostructured biomimetic materials is a new challenge in modern regenerative medicine. In order to develop functional substitutes for damaged organs or tissues, several methods have been used to create implants able to regenerate robust and durable bone. Electrospinning produces nonwoven scaffolds based on polymer nanofibers mimicking the fibrillar organization of bone extracellular matrix. Here, we describe a biomimetic 3D thick nanofibrous scaffold obtained by electrospinning of the biodegradable, bioresorbable and FDA-approved polymer, poly(ε-caprolactone). Such scaffold presents a thickness reaching one centimeter. We report here the demonstration that the designed nanostructured implant is able to induce in vivo bone regeneration. PMID:25538059

  17. 3D Printing of Scaffolds for Tissue Regeneration Applications.

    PubMed

    Do, Anh-Vu; Khorsand, Behnoush; Geary, Sean M; Salem, Aliasger K

    2015-08-26

    The current need for organ and tissue replacement, repair, and regeneration for patients is continually growing such that supply is not meeting demand primarily due to a paucity of donors as well as biocompatibility issues leading to immune rejection of the transplant. In order to overcome these drawbacks, scientists have investigated the use of scaffolds as an alternative to transplantation. These scaffolds are designed to mimic the extracellular matrix (ECM) by providing structural support as well as promoting attachment, proliferation, and differentiation with the ultimate goal of yielding functional tissues or organs. Initial attempts at developing scaffolds were problematic and subsequently inspired an interest in 3D printing as a mode for generating scaffolds. Utilizing three-dimensional printing (3DP) technologies, ECM-like scaffolds can be produced with a high degree of complexity, where fine details can be included at a micrometer level. In this Review, the criteria for printing viable and functional scaffolds, scaffolding materials, and 3DP technologies used to print scaffolds for tissue engineering are discussed. Creating biofunctional scaffolds could potentially help to meet the demand by patients for tissues and organs without having to wait or rely on donors for transplantation. PMID:26097108

  18. 3D Printing of Scaffolds for Tissue Regeneration Applications.

    PubMed

    Do, Anh-Vu; Khorsand, Behnoush; Geary, Sean M; Salem, Aliasger K

    2015-08-26

    The current need for organ and tissue replacement, repair, and regeneration for patients is continually growing such that supply is not meeting demand primarily due to a paucity of donors as well as biocompatibility issues leading to immune rejection of the transplant. In order to overcome these drawbacks, scientists have investigated the use of scaffolds as an alternative to transplantation. These scaffolds are designed to mimic the extracellular matrix (ECM) by providing structural support as well as promoting attachment, proliferation, and differentiation with the ultimate goal of yielding functional tissues or organs. Initial attempts at developing scaffolds were problematic and subsequently inspired an interest in 3D printing as a mode for generating scaffolds. Utilizing three-dimensional printing (3DP) technologies, ECM-like scaffolds can be produced with a high degree of complexity, where fine details can be included at a micrometer level. In this Review, the criteria for printing viable and functional scaffolds, scaffolding materials, and 3DP technologies used to print scaffolds for tissue engineering are discussed. Creating biofunctional scaffolds could potentially help to meet the demand by patients for tissues and organs without having to wait or rely on donors for transplantation.

  19. 3D conductive nanocomposite scaffold for bone tissue engineering

    PubMed Central

    Shahini, Aref; Yazdimamaghani, Mostafa; Walker, Kenneth J; Eastman, Margaret A; Hatami-Marbini, Hamed; Smith, Brenda J; Ricci, John L; Madihally, Sundar V; Vashaee, Daryoosh; Tayebi, Lobat

    2014-01-01

    Bone healing can be significantly expedited by applying electrical stimuli in the injured region. Therefore, a three-dimensional (3D) ceramic conductive tissue engineering scaffold for large bone defects that can locally deliver the electrical stimuli is highly desired. In the present study, 3D conductive scaffolds were prepared by employing a biocompatible conductive polymer, ie, poly(3,4-ethylenedioxythiophene) poly(4-styrene sulfonate) (PEDOT:PSS), in the optimized nanocomposite of gelatin and bioactive glass. For in vitro analysis, adult human mesenchymal stem cells were seeded in the scaffolds. Material characterizations using hydrogen-1 nuclear magnetic resonance, in vitro degradation, as well as thermal and mechanical analysis showed that incorporation of PEDOT:PSS increased the physiochemical stability of the composite, resulting in improved mechanical properties and biodegradation resistance. The outcomes indicate that PEDOT:PSS and polypeptide chains have close interaction, most likely by forming salt bridges between arginine side chains and sulfonate groups. The morphology of the scaffolds and cultured human mesenchymal stem cells were observed and analyzed via scanning electron microscope, micro-computed tomography, and confocal fluorescent microscope. Increasing the concentration of the conductive polymer in the scaffold enhanced the cell viability, indicating the improved microstructure of the scaffolds or boosted electrical signaling among cells. These results show that these conductive scaffolds are not only structurally more favorable for bone tissue engineering, but also can be a step forward in combining the tissue engineering techniques with the method of enhancing the bone healing by electrical stimuli. PMID:24399874

  20. Engineering multi-layered skeletal muscle tissue by using 3D microgrooved collagen scaffolds.

    PubMed

    Chen, Shangwu; Nakamoto, Tomoko; Kawazoe, Naoki; Chen, Guoping

    2015-12-01

    Preparation of three-dimensional (3D) micropatterned porous scaffolds remains a great challenge for engineering of highly organized tissues such as skeletal muscle tissue and cardiac tissue. Two-dimensional (2D) micropatterned surfaces with periodic features (several nanometers to less than 100 μm) are commonly used to guide the alignment of muscle myoblasts and myotubes and lead to formation of pre-patterned cell sheets. However, cell sheets from 2D patterned surfaces have limited thickness, and harvesting the cell sheets for implantation is inconvenient and can lead to less alignment of myotubes. 3D micropatterned scaffolds can promote cell alignment and muscle tissue formation. In this study, we developed a novel type of 3D porous collagen scaffolds with concave microgrooves that mimic muscle basement membrane to engineer skeletal muscle tissue. Highly aligned and multi-layered muscle bundle tissues were engineered by controlling the size of microgrooves and cell seeding concentration. Myoblasts in the engineered muscle tissue were well-aligned and had high expression of myosin heavy chain and synthesis of muscle extracellular matrix. The microgrooved collagen scaffolds could be used to engineer organized multi-layered muscle tissue for implantation to repair/restore the function of diseased tissues or be used to investigate the cell-cell interaction in 3D microscale topography.

  1. Fabricating gradient hydrogel scaffolds for 3D cell culture.

    PubMed

    Chatterjee, Kaushik; Young, Marian F; Simon, Carl G

    2011-05-01

    Optimizing cell-material interactions is critical for maximizing regeneration in tissue engineering. Combinatorial and high-throughput (CHT) methods can be used to systematically screen tissue scaffolds to identify optimal biomaterial properties. Previous CHT platforms in tissue engineering have involved a two-dimensional (2D) cell culture format where cells were cultured on material surfaces. However, these platforms are inadequate to predict cellular response in a three-dimensional (3D) tissue scaffold. We have developed a simple CHT platform to screen cell-material interactions in 3D culture format that can be applied to screen hydrogel scaffolds. Herein we provide detailed instructions on a method to prepare gradients in elastic modulus of photopolymerizable hydrogels.

  2. The medial scaffold of 3D unorganized point clouds.

    PubMed

    Leymarie, Frederic F; Kimia, Benjamin B

    2007-02-01

    We introduce the notion of the medial scaffold, a hierarchical organization of the medial axis of a 3D shape in the form of a graph constructed from special medial curves connecting special medial points. A key advantage of the scaffold is that it captures the qualitative aspects of shape in a hierarchical and tightly condensed representation. We propose an efficient and exact method for computing the medial scaffold based on a notion of propagation along the scaffold itself, starting from initial sources of the flow and constructing the scaffold during the propagation. We examine this method specifically in the context of an unorganized cloud of points in 3D, e.g., as obtained from laser range finders, which typically involve hundreds of thousands of points, but the ideas are generalizable to data arising from geometrically described surface patches. The computational bottleneck in the propagation-based scheme is in finding the initial sources of the flow. We thus present several ideas to avoid the unnecessary consideration of pairs of points which cannot possibly form a medial point source, such as the "visibility" of a point from another given a third point and the interaction of clusters of points. An application of using the medial scaffold for the representation of point samplings of real-life objects is also illustrated.

  3. Finite Element Analysis of Meniscal Anatomical 3D Scaffolds: Implications for Tissue Engineering

    PubMed Central

    Moroni, L; Lambers, F.M; Wilson, W; van Donkelaar, C.C; de Wijn, JR; Huiskesb, R; van Blitterswijk, C.A

    2007-01-01

    Solid Free-Form Fabrication (SFF) technologies allow the fabrication of anatomical 3D scaffolds from computer tomography (CT) or magnetic resonance imaging (MRI) patients’ dataset. These structures can be designed and fabricated with a variable, interconnected and accessible porous network, resulting in modulable mechanical properties, permeability, and architecture that can be tailored to mimic a specific tissue to replace or regenerate. In this study, we evaluated whether anatomical meniscal 3D scaffolds with matching mechanical properties and architecture are beneficial for meniscus replacement as compared to meniscectomy. After acquiring CT and MRI of porcine menisci, 3D fiber-deposited (3DF) scaffolds were fabricated with different architectures by varying the deposition pattern of the fibers comprising the final structure. The mechanical behaviour of 3DF scaffolds with different architectures and of porcine menisci was measured by static and dynamic mechanical analysis and the effect of these tissue engineering templates on articular cartilage was assessed by finite element analysis (FEA) and compared to healthy conditions or to meniscectomy. Results show that 3DF anatomical menisci scaffolds can be fabricated with pore different architectures and with mechanical properties matching those of natural menisci. FEA predicted a beneficial effect of meniscus replacement with 3D scaffolds in different mechanical loading conditions as compared to meniscectomy. No influence of the internal scaffold architecture was found on articular cartilage damage. Although FEA predictions should be further confirmed by in vitro and in vivo experiments, this study highlights meniscus replacement by SFF anatomical scaffolds as a potential alternative to meniscectomy. PMID:19662124

  4. Evaluating 3D Printed Biomaterials as Scaffolds for Vascularized Bone Tissue Engineering

    PubMed Central

    Wang, Martha O.; Vorwald, Charlotte E.; Dreher, Maureen L.; Mott, Eric J.; Cheng, Ming-Huei; Cinar, Ali; Mehdizadeh, Hamidreza; Somo, Sami; Dean, David; Brey, Eric M.; Fisher, John P.

    2015-01-01

    The recent proliferation of three dimensional (3D) printing technologies has allowed the exploration of increasing complex designs, and, furthermore, the consideration of 3D printed constructs for biological applications. However, there is an unmet need for a consistent set of tools for the design and evaluation of these biological 3D printed constructs, particularly as they relate to engineered tissues. For example, identifying the most advantageous construct parameters for the rapid vascularization of an engineered tissue - a critical parameter in regenerative medicine - is difficult without a common group of measures. We demonstrate here a toolbox to design, characterize, and evaluate 3D printed scaffolds for vascularized tissue regenerative medicine. Our toolbox (1) identifies the range of design specifications using a modular design, (2) nondestructively compares the 3D printed scaffolds to the design, (3) evaluates biocompatibility and mechanical properties, and (4) predicts host vessel integration. As a case study, we designed, fabricated, and evaluated polymer scaffolds using a poly(propylene fumarate) based resin. Our work highlights the potential for these tools to be combined as a consistent methodology for the evaluation of porous 3D printed constructs for regenerative medicine. PMID:25387454

  5. Mesoporous bioactive glass nanolayer-functionalized 3D-printed scaffolds for accelerating osteogenesis and angiogenesis.

    PubMed

    Zhang, Yali; Xia, Lunguo; Zhai, Dong; Shi, Mengchao; Luo, Yongxiang; Feng, Chun; Fang, Bing; Yin, Jingbo; Chang, Jiang; Wu, Chengtie

    2015-12-01

    The hierarchical microstructure, surface and interface of biomaterials are important factors influencing their bioactivity. Porous bioceramic scaffolds have been widely used for bone tissue engineering by optimizing their chemical composition and large-pore structure. However, the surface and interface of struts in bioceramic scaffolds are often ignored. The aim of this study is to incorporate hierarchical pores and bioactive components into the bioceramic scaffolds by constructing nanopores and bioactive elements on the struts of scaffolds and further improve their bone-forming activity. Mesoporous bioactive glass (MBG) modified β-tricalcium phosphate (MBG-β-TCP) scaffolds with a hierarchical pore structure and a functional strut surface (∼100 nm of MBG nanolayer) were successfully prepared via 3D printing and spin coating. The compressive strength and apatite-mineralization ability of MBG-β-TCP scaffolds were significantly enhanced as compared to β-TCP scaffolds without the MBG nanolayer. The attachment, viability, alkaline phosphatase (ALP) activity, osteogenic gene expression (Runx2, BMP2, OPN and Col I) and protein expression (OPN, Col I, VEGF, HIF-1α) of rabbit bone marrow stromal cells (rBMSCs) as well as the attachment, viability and angiogenic gene expression (VEGF and HIF-1α) of human umbilical vein endothelial cells (HUVECs) in MBG-β-TCP scaffolds were significantly upregulated compared with conventional bioactive glass (BG)-modified β-TCP (BG-β-TCP) and pure β-TCP scaffolds. Furthermore, MBG-β-TCP scaffolds significantly enhanced the formation of new bone in vivo as compared to BG-β-TCP and β-TCP scaffolds. The results suggest that application of the MBG nanolayer to modify 3D-printed bioceramic scaffolds offers a new strategy to construct hierarchically porous scaffolds with significantly improved physicochemical and biological properties, such as mechanical properties, osteogenesis, angiogenesis and protein expression for bone tissue

  6. Mesoporous bioactive glass nanolayer-functionalized 3D-printed scaffolds for accelerating osteogenesis and angiogenesis

    NASA Astrophysics Data System (ADS)

    Zhang, Yali; Xia, Lunguo; Zhai, Dong; Shi, Mengchao; Luo, Yongxiang; Feng, Chun; Fang, Bing; Yin, Jingbo; Chang, Jiang; Wu, Chengtie

    2015-11-01

    The hierarchical microstructure, surface and interface of biomaterials are important factors influencing their bioactivity. Porous bioceramic scaffolds have been widely used for bone tissue engineering by optimizing their chemical composition and large-pore structure. However, the surface and interface of struts in bioceramic scaffolds are often ignored. The aim of this study is to incorporate hierarchical pores and bioactive components into the bioceramic scaffolds by constructing nanopores and bioactive elements on the struts of scaffolds and further improve their bone-forming activity. Mesoporous bioactive glass (MBG) modified β-tricalcium phosphate (MBG-β-TCP) scaffolds with a hierarchical pore structure and a functional strut surface (~100 nm of MBG nanolayer) were successfully prepared via 3D printing and spin coating. The compressive strength and apatite-mineralization ability of MBG-β-TCP scaffolds were significantly enhanced as compared to β-TCP scaffolds without the MBG nanolayer. The attachment, viability, alkaline phosphatase (ALP) activity, osteogenic gene expression (Runx2, BMP2, OPN and Col I) and protein expression (OPN, Col I, VEGF, HIF-1α) of rabbit bone marrow stromal cells (rBMSCs) as well as the attachment, viability and angiogenic gene expression (VEGF and HIF-1α) of human umbilical vein endothelial cells (HUVECs) in MBG-β-TCP scaffolds were significantly upregulated compared with conventional bioactive glass (BG)-modified β-TCP (BG-β-TCP) and pure β-TCP scaffolds. Furthermore, MBG-β-TCP scaffolds significantly enhanced the formation of new bone in vivo as compared to BG-β-TCP and β-TCP scaffolds. The results suggest that application of the MBG nanolayer to modify 3D-printed bioceramic scaffolds offers a new strategy to construct hierarchically porous scaffolds with significantly improved physicochemical and biological properties, such as mechanical properties, osteogenesis, angiogenesis and protein expression for bone tissue

  7. Mesoporous bioactive glass nanolayer-functionalized 3D-printed scaffolds for accelerating osteogenesis and angiogenesis.

    PubMed

    Zhang, Yali; Xia, Lunguo; Zhai, Dong; Shi, Mengchao; Luo, Yongxiang; Feng, Chun; Fang, Bing; Yin, Jingbo; Chang, Jiang; Wu, Chengtie

    2015-12-01

    The hierarchical microstructure, surface and interface of biomaterials are important factors influencing their bioactivity. Porous bioceramic scaffolds have been widely used for bone tissue engineering by optimizing their chemical composition and large-pore structure. However, the surface and interface of struts in bioceramic scaffolds are often ignored. The aim of this study is to incorporate hierarchical pores and bioactive components into the bioceramic scaffolds by constructing nanopores and bioactive elements on the struts of scaffolds and further improve their bone-forming activity. Mesoporous bioactive glass (MBG) modified β-tricalcium phosphate (MBG-β-TCP) scaffolds with a hierarchical pore structure and a functional strut surface (∼100 nm of MBG nanolayer) were successfully prepared via 3D printing and spin coating. The compressive strength and apatite-mineralization ability of MBG-β-TCP scaffolds were significantly enhanced as compared to β-TCP scaffolds without the MBG nanolayer. The attachment, viability, alkaline phosphatase (ALP) activity, osteogenic gene expression (Runx2, BMP2, OPN and Col I) and protein expression (OPN, Col I, VEGF, HIF-1α) of rabbit bone marrow stromal cells (rBMSCs) as well as the attachment, viability and angiogenic gene expression (VEGF and HIF-1α) of human umbilical vein endothelial cells (HUVECs) in MBG-β-TCP scaffolds were significantly upregulated compared with conventional bioactive glass (BG)-modified β-TCP (BG-β-TCP) and pure β-TCP scaffolds. Furthermore, MBG-β-TCP scaffolds significantly enhanced the formation of new bone in vivo as compared to BG-β-TCP and β-TCP scaffolds. The results suggest that application of the MBG nanolayer to modify 3D-printed bioceramic scaffolds offers a new strategy to construct hierarchically porous scaffolds with significantly improved physicochemical and biological properties, such as mechanical properties, osteogenesis, angiogenesis and protein expression for bone tissue

  8. Porous three-dimensional carbon nanotube scaffolds for tissue engineering.

    PubMed

    Lalwani, Gaurav; Gopalan, Anu; D'Agati, Michael; Sankaran, Jeyantt Srinivas; Judex, Stefan; Qin, Yi-Xian; Sitharaman, Balaji

    2015-10-01

    Assembly of carbon nanomaterials into three-dimensional (3D) architectures is necessary to harness their unique physiochemical properties for tissue engineering and regenerative medicine applications. Herein, we report the fabrication and comprehensive cytocompatibility assessment of 3D chemically crosslinked macrosized (5-8 mm height and 4-6 mm diameter) porous carbon nanotube (CNT) scaffolds. Scaffolds prepared via radical initiated thermal crosslinking of single- or multiwalled CNTs (SWCNTs and MWCNTs) possess high porosity (>80%), and nano-, micro-, and macroscale interconnected pores. MC3T3 preosteoblast cells on MWCNT and SWCNT scaffolds showed good cell viability comparable to poly(lactic-co-glycolic) acid (PLGA) scaffolds after 5 days. Confocal live cell and immunofluorescence imaging showed that MC3T3 cells were metabolically active and could attach, proliferate, and infiltrate MWCNT and SWCNT scaffolds. SEM imaging corroborated cell attachment and spreading and suggested that cell morphology is governed by scaffold surface roughness. MC3T3 cells were elongated on scaffolds with high surface roughness (MWCNTs) and rounded on scaffolds with low surface roughness (SWCNTs). The surface roughness of scaffolds may be exploited to control cellular morphology and, in turn, govern cell fate. These results indicate that crosslinked MWCNTs and SWCNTs scaffolds are cytocompatible, and open avenues toward development of multifunctional all-carbon scaffolds for tissue engineering applications.

  9. 3D printing facilitated scaffold-free tissue unit fabrication.

    PubMed

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

    2014-06-01

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

  10. 3D Printing Facilitated Scaffold-free Tissue Unit Fabrication

    PubMed Central

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

    2014-01-01

    Tissue spheroids hold great potential in tissue engineering as building blocks to assemble into functional tissues. To date, agarose molds have been extensively used to facilitate fusion process of tissue spheroids. As a molding material, agarose typically requires low temperature plates for gelation and/or heated dispenser units. Here, we proposed and developed an alginate-based, direct 3D mold-printing technology: 3D printing micro-droplets of alginate solution into biocompatible, bio-inert alginate hydrogel molds for the fabrication of scaffold-free tissue engineering constructs. Specifically, we developed a 3D printing technology to deposit micro-droplets of alginate solution on calcium containing substrates in a layer-by-layer fashion to prepare ring-shaped 3D hydrogel molds. Tissue spheroids composed of 50% endothelial cells and 50% smooth muscle cells were robotically placed into the 3D printed alginate molds using a 3D printer, and were found to rapidly fuse into toroid-shaped tissue units. Histological and immunofluorescence analysis indicated that the cells secreted collagen type I playing a critical role in promoting cell-cell adhesion, tissue formation and maturation. PMID:24717646

  11. Functionalization of 3D scaffolds with protein-releasing biomaterials for intracellular delivery.

    PubMed

    Seras-Franzoso, Joaquin; Steurer, Christoph; Roldán, Mònica; Vendrell, Meritxell; Vidaurre-Agut, Carla; Tarruella, Anna; Saldaña, Laura; Vilaboa, Nuria; Parera, Marc; Elizondo, Elisa; Ratera, Imma; Ventosa, Nora; Veciana, Jaume; Campillo-Fernández, Alberto J; García-Fruitós, Elena; Vázquez, Esther; Villaverde, Antonio

    2013-10-10

    Appropriate combinations of mechanical and biological stimuli are required to promote proper colonization of substrate materials in regenerative medicine. In this context, 3D scaffolds formed by compatible and biodegradable materials are under continuous development in an attempt to mimic the extracellular environment of mammalian cells. We have here explored how novel 3D porous scaffolds constructed by polylactic acid, polycaprolactone or chitosan can be decorated with bacterial inclusion bodies, submicron protein particles formed by releasable functional proteins. A simple dipping-based decoration method tested here specifically favors the penetration of the functional particles deeper than 300μm from the materials' surface. The functionalized surfaces support the intracellular delivery of biologically active proteins to up to more than 80% of the colonizing cells, a process that is slightly influenced by the chemical nature of the scaffold. The combination of 3D soft scaffolds and protein-based sustained release systems (Bioscaffolds) offers promise in the fabrication of bio-inspired hybrid matrices for multifactorial control of cell proliferation in tissue engineering under complex architectonic setting-ups.

  12. Design of novel 3D gene activated PEG scaffolds with ordered pore structure.

    PubMed

    Orsi, Silvia; Guarnieri, Daniela; Netti, Paolo A

    2010-03-01

    The ability to genetically modify cells seeded inside synthetic hydrogel scaffolds offers a suitable approach to induce and control tissue repair and regeneration guiding cell fate. In fact the transfected cells can act as local in vivo bioreactor, secreting plasmid encoded proteins that augment tissue regeneration processes. We have realized a DNA bioactivated high porous poly(ethylene glycol) (PEG) matrix by polyethyleneimine (PEI)/DNA complexes adsorption. As the design of the microarchitectural features of a scaffold also contributes to promote and influence cell fate, we appropriately designed the inner structure of gene activated PEG hydrogels by gelatine microparticles templating. Microarchitectural properties of the scaffold were analysed by scanning electron microscopy. 3D cell migration and transfection were monitored through time-lapse videomicroscopy and confocal laser scanning microscopy.

  13. Living Bacterial Sacrificial Porogens to Engineer Decellularized Porous Scaffolds

    PubMed Central

    Xu, Feng; Sridharan, BanuPriya; Durmus, Naside Gozde; Wang, ShuQi; Yavuz, Ahmet Sinan; Gurkan, Umut Atakan; Demirci, Utkan

    2011-01-01

    Decellularization and cellularization of organs have emerged as disruptive methods in tissue engineering and regenerative medicine. Porous hydrogel scaffolds have widespread applications in tissue engineering, regenerative medicine and drug discovery as viable tissue mimics. However, the existing hydrogel fabrication techniques suffer from limited control over pore interconnectivity, density and size, which leads to inefficient nutrient and oxygen transport to cells embedded in the scaffolds. Here, we demonstrated an innovative approach to develop a new platform for tissue engineered constructs using live bacteria as sacrificial porogens. E.coli were patterned and cultured in an interconnected three-dimensional (3D) hydrogel network. The growing bacteria created interconnected micropores and microchannels. Then, the scafold was decellularized, and bacteria were eliminated from the scaffold through lysing and washing steps. This 3D porous network method combined with bioprinting has the potential to be broadly applicable and compatible with tissue specific applications allowing seeding of stem cells and other cell types. PMID:21552485

  14. Living bacterial sacrificial porogens to engineer decellularized porous scaffolds.

    PubMed

    Xu, Feng; Sridharan, BanuPriya; Durmus, Naside Gozde; Wang, ShuQi; Yavuz, Ahmet Sinan; Gurkan, Umut Atakan; Demirci, Utkan

    2011-01-01

    Decellularization and cellularization of organs have emerged as disruptive methods in tissue engineering and regenerative medicine. Porous hydrogel scaffolds have widespread applications in tissue engineering, regenerative medicine and drug discovery as viable tissue mimics. However, the existing hydrogel fabrication techniques suffer from limited control over pore interconnectivity, density and size, which leads to inefficient nutrient and oxygen transport to cells embedded in the scaffolds. Here, we demonstrated an innovative approach to develop a new platform for tissue engineered constructs using live bacteria as sacrificial porogens. E.coli were patterned and cultured in an interconnected three-dimensional (3D) hydrogel network. The growing bacteria created interconnected micropores and microchannels. Then, the scafold was decellularized, and bacteria were eliminated from the scaffold through lysing and washing steps. This 3D porous network method combined with bioprinting has the potential to be broadly applicable and compatible with tissue specific applications allowing seeding of stem cells and other cell types.

  15. Time-Dependent Effects of Pre-Aging 3D Polymer Scaffolds in Cell Culture Medium on Cell Proliferation.

    PubMed

    Chatterjee, Kaushik; Hung, Stevephen; Kumar, Girish; Simon, Carl G

    2012-01-01

    Protein adsorption is known to direct biological response to biomaterials and is important in determining cellular response in tissue scaffolds. In this study we investigated the effect of the duration of protein adsorption to 3D polymer scaffolds on cell attachment and proliferation. 3D macro-porous polymer scaffolds were pre-aged in serum-containing culture medium for 5 min, 1 d or 7 d prior to seeding osteoblasts. The total amount of protein adsorbed was found to increase with pre-ageing time. Cell attachment and proliferation were measured 1 d and 14 d, respectively, after cell seeding. Osteoblast proliferation, but not attachment, increased with scaffold pre-ageing time and amount of adsorbed serum protein. These results demonstrate that the amount of time that scaffolds are exposed to serum-containing medium can affect cell proliferation and suggest that these effects are mediated by differences in the amount of protein adsorption.

  16. Combinatorial screening of osteoblast response to 3D calcium phosphate/poly(ε-caprolactone) scaffolds using gradients and arrays

    PubMed Central

    Chatterjee, Kaushik; Sun, Limin; Chow, Laurence C.; Young, Marian F.; Simon, Carl G.

    2012-01-01

    There is a need for combinatorial and high-throughput methods for screening cell–biomaterial interactions to maximize tissue generation in scaffolds. Current methods employ a flat two-dimensional (2D) format even though three-dimensional (3D) scaffolds are more representative of the tissue environment in vivo and cells are responsive to topographical differences of 2D substrates and 3D scaffolds. Thus, combinatorial libraries of 3D porous scaffolds were developed and used to screen the effect of nano-amorphous calcium phosphate (nACP) particles on osteoblast response. Increasing nACP content in poly (ε-caprolactone) (PCL) scaffolds promoted osteoblast adhesion and proliferation. The nACP-containing scaffolds released calcium and phosphate ions which are known to activate osteoblast function. Scaffold libraries were fabricated in two formats, gradients and arrays, and the magnitude of the effect of nACP on osteoblast proliferation was greater for arrays than gradients. The enhanced response in arrays can be explained by differences in cell culture designs, diffusional effects and differences in the ratio of “scaffold mass to culture medium”. These results introduce a gradient library approach for screening large pore 3D scaffolds and demonstrate that inclusion of the nACP particles enhances osteoblast proliferation in 3D scaffolds. Further, comparison of gradients and arrays suggests that gradients were more sensitive for detecting effects of scaffold composition on cell adhesion (short time points, 1 day) whereas arrays were more sensitive at detecting effects on cell proliferation (longer time points, 14 day). PMID:21074846

  17. Improved Human Bone Marrow Mesenchymal Stem Cell Osteogenesis in 3D Bioprinted Tissue Scaffolds with Low Intensity Pulsed Ultrasound Stimulation

    PubMed Central

    Zhou, Xuan; Castro, Nathan J.; Zhu, Wei; Cui, Haitao; Aliabouzar, Mitra; Sarkar, Kausik; Zhang, Lijie Grace

    2016-01-01

    3D printing and ultrasound techniques are showing great promise in the evolution of human musculoskeletal tissue repair and regeneration medicine. The uniqueness of the present study was to combine low intensity pulsed ultrasound (LIPUS) and advanced 3D printing techniques to synergistically improve growth and osteogenic differentiation of human mesenchymal stem cells (MSC). Specifically, polyethylene glycol diacrylate bioinks containing cell adhesive Arginine-Glycine-Aspartic acid-Serene (RGDS) peptide and/or nanocrystalline hydroxyapatite (nHA) were used to fabricate 3D scaffolds with different geometric patterns via novel table-top stereolithography 3D printer. The resultant scaffolds provide a highly porous and interconnected 3D environment to support cell proliferation. Scaffolds with small square pores were determined to be the optimal geometric pattern for MSC attachment and growth. The optimal LIPUS working parameters were determined to be 1.5 MHz, 20% duty cycle with 150 mW/cm2 intensity. Results demonstrated that RGDS peptide and nHA containing 3D printed scaffolds under LIPUS treatment can greatly promote MSC proliferation, alkaline phosphatase activity, calcium deposition and total protein content. These results illustrate the effectiveness of the combination of LIPUS and biomimetic 3D printing scaffolds as a valuable combinatorial tool for improved MSC function, thus make them promising for future clinical and various regenerative medicine application. PMID:27597635

  18. Improved Human Bone Marrow Mesenchymal Stem Cell Osteogenesis in 3D Bioprinted Tissue Scaffolds with Low Intensity Pulsed Ultrasound Stimulation.

    PubMed

    Zhou, Xuan; Castro, Nathan J; Zhu, Wei; Cui, Haitao; Aliabouzar, Mitra; Sarkar, Kausik; Zhang, Lijie Grace

    2016-01-01

    3D printing and ultrasound techniques are showing great promise in the evolution of human musculoskeletal tissue repair and regeneration medicine. The uniqueness of the present study was to combine low intensity pulsed ultrasound (LIPUS) and advanced 3D printing techniques to synergistically improve growth and osteogenic differentiation of human mesenchymal stem cells (MSC). Specifically, polyethylene glycol diacrylate bioinks containing cell adhesive Arginine-Glycine-Aspartic acid-Serene (RGDS) peptide and/or nanocrystalline hydroxyapatite (nHA) were used to fabricate 3D scaffolds with different geometric patterns via novel table-top stereolithography 3D printer. The resultant scaffolds provide a highly porous and interconnected 3D environment to support cell proliferation. Scaffolds with small square pores were determined to be the optimal geometric pattern for MSC attachment and growth. The optimal LIPUS working parameters were determined to be 1.5 MHz, 20% duty cycle with 150 mW/cm(2) intensity. Results demonstrated that RGDS peptide and nHA containing 3D printed scaffolds under LIPUS treatment can greatly promote MSC proliferation, alkaline phosphatase activity, calcium deposition and total protein content. These results illustrate the effectiveness of the combination of LIPUS and biomimetic 3D printing scaffolds as a valuable combinatorial tool for improved MSC function, thus make them promising for future clinical and various regenerative medicine application. PMID:27597635

  19. Improved Human Bone Marrow Mesenchymal Stem Cell Osteogenesis in 3D Bioprinted Tissue Scaffolds with Low Intensity Pulsed Ultrasound Stimulation.

    PubMed

    Zhou, Xuan; Castro, Nathan J; Zhu, Wei; Cui, Haitao; Aliabouzar, Mitra; Sarkar, Kausik; Zhang, Lijie Grace

    2016-09-06

    3D printing and ultrasound techniques are showing great promise in the evolution of human musculoskeletal tissue repair and regeneration medicine. The uniqueness of the present study was to combine low intensity pulsed ultrasound (LIPUS) and advanced 3D printing techniques to synergistically improve growth and osteogenic differentiation of human mesenchymal stem cells (MSC). Specifically, polyethylene glycol diacrylate bioinks containing cell adhesive Arginine-Glycine-Aspartic acid-Serene (RGDS) peptide and/or nanocrystalline hydroxyapatite (nHA) were used to fabricate 3D scaffolds with different geometric patterns via novel table-top stereolithography 3D printer. The resultant scaffolds provide a highly porous and interconnected 3D environment to support cell proliferation. Scaffolds with small square pores were determined to be the optimal geometric pattern for MSC attachment and growth. The optimal LIPUS working parameters were determined to be 1.5 MHz, 20% duty cycle with 150 mW/cm(2) intensity. Results demonstrated that RGDS peptide and nHA containing 3D printed scaffolds under LIPUS treatment can greatly promote MSC proliferation, alkaline phosphatase activity, calcium deposition and total protein content. These results illustrate the effectiveness of the combination of LIPUS and biomimetic 3D printing scaffolds as a valuable combinatorial tool for improved MSC function, thus make them promising for future clinical and various regenerative medicine application.

  20. Carboxy-Methyl-Cellulose (CMC) hydrogel-filled 3-D scaffold: Preliminary study through a 3-D antiproliferative activity of Centella asiatica extract

    NASA Astrophysics Data System (ADS)

    Aizad, Syazwan; Yahaya, Badrul Hisham; Zubairi, Saiful Irwan

    2015-09-01

    This study focuses on the effects of using the water extract from Centella asiatica on the mortality of human lung cancer cells (A549) with the use of novel 3-D scaffolds infused with CMC hydrogel. A biodegradable polymer, poly (hydroxybutyrate-co-hydroxyvalerate) (PHBV) was used in this study as 3-D scaffolds, with some modifications made by introducing the gel structure on its pore, which provides a great biomimetic microenvironment for cells to grow apart from increasing the interaction between the cells and cell-bioactive extracts. The CMC showed a good hydrophilic characteristic with mean contact angle of 24.30 ± 22.03°. To ensure the CMC gel had good attachments with the scaffolds, a surface treatment was made before the CMC gel was infused into the scaffolds. The results showed that these modified scaffolds contained 42.41 ± 0.14% w/w of CMC gel, which indicated that the gel had already filled up the entire pore of 3-D scaffolds. Besides, the infused hydrogel scaffolds took only 24 hours to be saturated when absorbing the water. The viability of cancer cells by MTS assay after being treated with Centella asiatica showed that the scaffolds infused with CMC hydrogel had the cell viability of 46.89 ± 1.20% followed by porous 3-D model with 57.30 ± 1.60% of cell viability, and the 2-D model with 67.10 ± 1.10% of cell viability. The inhibitory activity in cell viability between 2-D and 3-D models did not differ significantly (p>0.05) due to the limitation of time in incubating the extract with the cell in the 3-D model microenvironment. In conclusion, with the application of 3-D scaffolds infused with CMC hydrogel, the extracts of Centella asiatica has been proven to have the ability to kill cancer cells and have a great potential to become one of the alternative methods in treating cancer patients.

  1. 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.

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

    PubMed

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

    2015-09-01

    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.

  3. Rapid prototyping for tissue-engineered bone scaffold by 3D printing and biocompatibility study

    PubMed Central

    He, Hui-Yu; Zhang, Jia-Yu; Mi, Xue; Hu, Yang; Gu, Xiao-Yu

    2015-01-01

    The prototyping of tissue-engineered bone scaffold (calcined goat spongy bone-biphasic ceramic composite/PVA gel) by 3D printing was performed, and the biocompatibility of the fabricated bone scaffold was studied. Pre-designed STL file was imported into the GXYZ303010-XYLE 3D printing system, and the tissue-engineered bone scaffold was fabricated by 3D printing using gel extrusion. Rabbit bone marrow stromal cells (BMSCs) were cultured in vitro and then inoculated to the sterilized bone scaffold obtained by 3D printing. The growth of rabbit BMSCs on the bone scaffold was observed under the scanning electron microscope (SEM). The effect of the tissue-engineered bone scaffold on the proliferation and differentiation of rabbit BMSCs using MTT assay. Universal testing machine was adopted to test the tensile strength of the bone scaffold. The leachate of the bone scaffold was prepared and injected into the New Zealand rabbits. Cytotoxicity test, acute toxicity test, pyrogenic test and intracutaneous stimulation test were performed to assess the biocompatibility of the bone scaffold. Bone scaffold manufactured by 3D printing had uniform pore size with the porosity of about 68.3%. The pores were well interconnected, and the bone scaffold showed excellent mechanical property. Rabbit BMSCs grew and proliferated on the surface of the bone scaffold after adherence. MTT assay indicated that the proliferation and differentiation of rabbit BMSCs on the bone scaffold did not differ significantly from that of the cells in the control. In vivo experiments proved that the bone scaffold fabricated by 3D printing had no acute toxicity, pyrogenic reaction or stimulation. Bone scaffold manufactured by 3D printing allows the rabbit BMSCs to adhere, grow and proliferate and exhibits excellent biomechanical property and high biocompatibility. 3D printing has a good application prospect in the prototyping of tissue-engineered bone scaffold. PMID:26380018

  4. Rapid prototyping for tissue-engineered bone scaffold by 3D printing and biocompatibility study.

    PubMed

    He, Hui-Yu; Zhang, Jia-Yu; Mi, Xue; Hu, Yang; Gu, Xiao-Yu

    2015-01-01

    The prototyping of tissue-engineered bone scaffold (calcined goat spongy bone-biphasic ceramic composite/PVA gel) by 3D printing was performed, and the biocompatibility of the fabricated bone scaffold was studied. Pre-designed STL file was imported into the GXYZ303010-XYLE 3D printing system, and the tissue-engineered bone scaffold was fabricated by 3D printing using gel extrusion. Rabbit bone marrow stromal cells (BMSCs) were cultured in vitro and then inoculated to the sterilized bone scaffold obtained by 3D printing. The growth of rabbit BMSCs on the bone scaffold was observed under the scanning electron microscope (SEM). The effect of the tissue-engineered bone scaffold on the proliferation and differentiation of rabbit BMSCs using MTT assay. Universal testing machine was adopted to test the tensile strength of the bone scaffold. The leachate of the bone scaffold was prepared and injected into the New Zealand rabbits. Cytotoxicity test, acute toxicity test, pyrogenic test and intracutaneous stimulation test were performed to assess the biocompatibility of the bone scaffold. Bone scaffold manufactured by 3D printing had uniform pore size with the porosity of about 68.3%. The pores were well interconnected, and the bone scaffold showed excellent mechanical property. Rabbit BMSCs grew and proliferated on the surface of the bone scaffold after adherence. MTT assay indicated that the proliferation and differentiation of rabbit BMSCs on the bone scaffold did not differ significantly from that of the cells in the control. In vivo experiments proved that the bone scaffold fabricated by 3D printing had no acute toxicity, pyrogenic reaction or stimulation. Bone scaffold manufactured by 3D printing allows the rabbit BMSCs to adhere, grow and proliferate and exhibits excellent biomechanical property and high biocompatibility. 3D printing has a good application prospect in the prototyping of tissue-engineered bone scaffold.

  5. Formation of Neural Networks in 3D Scaffolds Fabricated by Means of Laser Microstereolithography.

    PubMed

    Vedunova, M V; Timashev, P S; Mishchenko, T A; Mitroshina, E V; Koroleva, A V; Chichkov, B N; Panchenko, V Ya; Bagratashvili, V N; Mukhina, I V

    2016-08-01

    We developed and tested new 3D scaffolds for neurotransplantation. Scaffolds of predetermined architectonic were prepared using microstereolithography technique. Scaffolds were highly biocompatible with the nervous tissue cells. In vitro studies showed that the material of fabricated scaffolds is not toxic for dissociated brain cells and promotes the formation of functional neural networks in the matrix. These results demonstrate the possibility of fabrication of tissue-engineering constructs for neurotransplantation based on created scaffolds. PMID:27595153

  6. Optimization of composition, structure and mechanical strength of bioactive 3-D glass-ceramic scaffolds for bone substitution.

    PubMed

    Baino, Francesco; Ferraris, Monica; Bretcanu, Oana; Verné, Enrica; Vitale-Brovarone, Chiara

    2013-03-01

    Fabrication of 3-D highly porous, bioactive, and mechanically competent scaffolds represents a significant challenge of bone tissue engineering. In this work, Bioglass®-derived glass-ceramic scaffolds actually fulfilling this complex set of requirements were successfully produced through the sponge replication method. Scaffold processing parameters and sintering treatment were carefully designed in order to obtain final porous bodies with pore content (porosity above 70 %vol), trabecular architecture and mechanical properties (compressive strength up to 3 MPa) analogous to those of the cancellous bone. Influence of the Bioglass® particles size on the structural and mechanical features of the sintered scaffolds was considered and discussed. Relationship between porosity and mechanical strength was investigated and modeled. Three-dimensional architecture, porosity, mechanical strength and in vitro bioactivity of the optimized Bioglass®-derived scaffolds were also compared to those of CEL2-based glass-ceramic scaffolds (CEL2 is an experimental bioactive glass originally developed by the authors at Politecnico di Torino) fabricated by the same processing technique, in an attempt at understanding the role of different bioactive glass composition on the major features of scaffolds prepared by the same method.

  7. Proliferation and enrichment of CD133+ glioblastoma cancer stem cells on 3D chitosan-alginate scaffolds

    PubMed Central

    Kievit, Forrest M.; Florczyk, Stephen J.; Leung, Matthew C.; Wang, Kui; Wu, Jennifer D.; Silber, John R.; Ellenbogen, Richard G.; Lee, Jerry S.H.; Zhang, Miqin

    2014-01-01

    Emerging evidence implicates cancer stem cells (CSCs) as primary determinants of the clinical behavior of human cancers, representing an ideal target for next-generation anticancer therapies. However CSCs are difficult to propagate in vitro, severely limiting the study of CSC biology and drug development. Here we report that growing cells from glioblastoma (GBM) cell lines on three dimensional (3D) porous chitosan-alginate (CA) scaffolds dramatically promotes the proliferation and enrichment of cells possessing the hallmarks of CSCs. CA scaffold-grown cells were found more tumorigenic in nude mouse xenografts than cells grown from monolayers. Growing in CA scaffolds rapidly promoted expression of genes involved in the epithelial-to-mesenchymal transition that has been implicated in the genesis of CSCs. Our results indicate that CA scaffolds have utility as a simple and inexpensive means to cultivate CSCs in vitro in support of studies to understand CSC biology and develop more effective anti-cancer therapies. PMID:25109438

  8. Electrophoretic deposition of porous hydroxyapatite scaffold.

    PubMed

    Ma, J; Wang, C; Peng, K W

    2003-09-01

    Bioactive porous hydroxyapatite (HA) scaffold was fabricated using electrophoretic deposition (EPD) technique in the present work. Bulk HA scaffold was achieved by repeated deposition. The green scaffold was sintered at 1200 degrees C to 82% of the theoretical density. Scanning electron microscopy examination and mercury porosimetry measurement have shown that the porosity remains interconnected and a range of pore size from several microns to hundreds of microns was obtained. X-ray diffraction analysis was performed and confirmed that there is no HA decomposition during the sintering process. Mechanical characterization has also shown that the EPD scaffold possesses excellent properties. Cell culturing experiment was carried out and the result shows that the scaffold bioactivity is not only dependent on the interconnectivity of the pores, but also the pore size.

  9. Preliminary study of surface modification of 3D Poly (ɛ - caprolactone) scaffolds by ultrashort laser irradiation

    NASA Astrophysics Data System (ADS)

    Daskalova, A.; Bliznakova, I.; Iordanova, E.; Yankov, G.; Grozeva, M.; Ostrowska, B.

    2016-02-01

    Three - dimensional poly (e- caprolactone) (PCL) scaffolds as suitable biocompatible material for manufacturing tissue replacements are utilized for tissue engineering purposes. The porous structures are fabricated by rapid prototyping method (Bioscaffolder) based on hypodermic dispensing process. The consecution of experiments demonstrated the possibility on creation of surface micro formations, applying different laser fluences, at 1 kHz repetition rate for fixed time of exposure 1 sec at 800 nm central wavelength. The combination of both methods offers possibilities for successful production of 3D matrices with modified surfaces. The obtained results of laser - induced surface modifications of PCL demonstrate the potential of the method to microprocess this kind of material for possible applications in regenerative medicine.

  10. A review: fabrication of porous polyurethane scaffolds.

    PubMed

    Janik, H; Marzec, M

    2015-03-01

    The aim of tissue engineering is the fabrication of three-dimensional scaffolds that can be used for the reconstruction and regeneration of damaged or deformed tissues and organs. A wide variety of techniques have been developed to create either fibrous or porous scaffolds from polymers, metals, composite materials and ceramics. However, the most promising materials are biodegradable polymers due to their comprehensive mechanical properties, ability to control the rate of degradation and similarities to natural tissue structures. Polyurethanes (PUs) are attractive candidates for scaffold fabrication, since they are biocompatible, and have excellent mechanical properties and mechanical flexibility. PU can be applied to various methods of porous scaffold fabrication, among which are solvent casting/particulate leaching, thermally induced phase separation, gas foaming, emulsion freeze-drying and melt moulding. Scaffold properties obtained by these techniques, including pore size, interconnectivity and total porosity, all depend on the thermal processing parameters, and the porogen agent and solvents used. In this review, various polyurethane systems for scaffolds are discussed, as well as methods of fabrication, including the latest developments, and their advantages and disadvantages.

  11. Superelastic, superabsorbent and 3D nanofiber-assembled scaffold for tissue engineering.

    PubMed

    Chen, Weiming; Ma, Jun; Zhu, Lei; Morsi, Yosry; Ei-Hamshary, Hany; Al-Deyab, Salem S; Mo, Xiumei

    2016-06-01

    Fabrication of 3D scaffold to mimic the nanofibrous structure of the nature extracellular matrix (ECM) with appropriate mechanical properties and excellent biocompatibility, remain an important technical challenge in tissue engineering. The present study reports the strategy to fabricate a 3D nanofibrous scaffold with similar structure to collagen in ECM by combining electrospinning and freeze-drying technique. With the technique reported here, a nanofibrous structure scaffold with hydrophilic and superabsorbent properties can be readily prepared by Gelatin and Polylactic acid (PLA). In wet state the scaffold also shows a super-elastic property, which could bear a compressive strain as high as 80% and recovers its original shape afterwards. Moreover, after 6 days of culture, L-929 cells grow, proliferate and infiltrated into the scaffold. The results suggest that this 3D nanofibrous scaffold would be promising for varied field of tissue engineering application.

  12. [Applications of Porous Scaffolds in Muscle Tissue Engineering].

    PubMed

    Sun, Yan; Zou, Ling; Liu, Jun

    2015-12-01

    Scaffold is one of the key elements required for tissue engineering. Porous scaffolds have several special advantages for muscle tissue engineering, and they are beneficial to cell survival, myogenic differentiation, and vascular ingrowth. The performance of porous scaffolds is closely related to the property of the biomaterials used. Additionally, the pore size and porosity may affect cell adhesion, proliferation, and differentiation. This review focuses on the application of porous scaffolds in muscle tissue engineering, including their categories, application, and advantages.

  13. Cell Proliferation on Macro/Nano Surface Structure and Collagen Immobilization of 3D Polycaprolactone Scaffolds.

    PubMed

    Park, Young-Ouk; Myung, Sung-Woon; Kook, Min-Suk; Jung, Sang-Chul; Kim, Byung-Hoon

    2016-02-01

    In this study, 3D polycaprolactone (PCL) scaffolds were fabricated by 3D printing technique. The macro/nano morphology of, 3D PCL scaffolds surface was etched with oxygen plasma. Acrylic acid (AA) plasma-polymerization was performed to functionalize the macro/nano surface with carboxyl groups and then collagen was immobilized with plasma-polymerized 3D PCL scaffolds. After O2 plasma and AA plasma-polymerization, contact angles were decreased. The FE-SEM and AFM results showed that O2 plasma is increased the surface roughness. The MTT assay results showed that proliferation of the M3CT3-E1 cells increased on the oxygen plasma treated and collagen immobilized 3D PCL scaffolds. PMID:27433597

  14. Cell culture and characterization of cross-linked poly(vinyl alcohol)-g-starch 3D scaffold for tissue engineering.

    PubMed

    Hsieh, Wen-Chuan; Liau, Jiun-Jia

    2013-10-15

    The research goal of this experiment is chemically to cross-link poly(vinyl alcohol) (PVA) and starch to form a 3D scaffold that is effective water absorbent, has a stable structure, and supports cell growth. PVA and starch can be chemically cross-linked to form a PVA-g-starch 3D scaffold polymer, as observed by Fourier transform infrared spectroscopy (FTIR), with an absorbency of up to 800%. Tensile testing reveals that, as the amount of starch increases, the strength of the 3D scaffold strength reaches 4×10(-2) MPa. Scanning electron microscope (SEM) observations of the material reveal that the 3D scaffold is highly porous formed using a homogenizer at 500 rpm. In an enzymatic degradation, the 3D scaffold was degraded by various enzymes at a rate of up to approximately 30-60% in 28 days. In vitro tests revealed that cells proliferate and grow in the 3D scaffold material. Energy dispersive spectrometer (EDS) analysis further verified that the bio-compatibility of this scaffold. PMID:23987384

  15. Bone response to 3-D periodic hydroxyapatite scaffolds with and without tailored microporosity to deliver bone morphogenetic protein 2.

    SciTech Connect

    Eurell, Jo Ann; Dellinger, Jennifer Gwynne; Cesarano, Joseph, III; Jamison, Russell D.

    2005-06-01

    The in vivo bone response of 3D periodic hydroxyapatite (HA) scaffolds is investigated. Two groups of HA scaffolds (11 mm diameter x 3.5 mm thick) are fabricated by direct-write assembly of a concentrated HA ink. The scaffolds consist of cylindrical rods periodically arranged into four quadrants with varying separation distances between rods. In the first group, HA rods (250 {micro}m in diameter) are patterned to create pore channels, whose areal dimensions are 250 x 250 {micro}m{sup 2} in quadrant 1, 250 x 500 {micro}m{sup 2} in quadrants 2 and 4, and 500 x 500 {micro}m{sup 2} in quadrant 3. In the second group, HA rods (400 {micro}m in diameter) are patterned to create pore channels, whose areal dimensions of 500 x 500 {micro}m{sup 2} in quadrant 1, 500 x 750 {micro}m{sup 2} in quadrants 2 and 4, and 750 x 750 {micro}m{sup 2} in quadrant 3. Each group of scaffolds is partially densified by sintering at 1200 C prior to being implanted bilaterally in trephine defects of skeletally mature New Zealand White rabbits. Their tissue response is evaluated at 8 and 16 weeks using micro-computed tomography, histology, and scanning electron microscopy. New trabecular bone is conducted rapidly and efficiently across substantial distances within these patterned 3D HA scaffolds. Our observations suggest that HA rods are first coated with a layer of new bone followed by subsequent scaffold infilling via outward and inward radial growth of the coated regions. Direct-write assembly of 3D periodic scaffolds composed of micro-porous HA rods arrayed to produce macro-pores that are size-matched to trabecular bone may represent an optimal strategy for bone repair and replacement structures.

  16. Electrospinning of small diameter 3-D nanofibrous tubular scaffolds with controllable nanofiber orientations for vascular grafts.

    PubMed

    Wu, Huijun; Fan, Jintu; Chu, Chih-Chang; Wu, Jun

    2010-12-01

    The control of nanofiber orientation in nanofibrous tubular scaffolds can benefit the cell responses along specific directions. For small diameter tubular scaffolds, however, it becomes difficult to engineer nanofiber orientation. This paper reports a novel electrospinning technique for the fabrication of 3-D nanofibrous tubular scaffolds with controllable nanofiber orientations. Synthetic absorbable poly-ε-caprolactone (PCL) was used as the model biomaterial to demonstrate this new electrospinning technique. Electrospun 3-D PCL nanofibrous tubular scaffolds of 4.5 mm in diameter with different nanofiber orientations (viz. circumferential, axial, and combinations of circumferential and axial directions) were successfully fabricated. The degree of nanofiber alignment in the electrospun 3-D tubular scaffolds was quantified by using the fast Fourier transform (FFT) analysis. The results indicated that excellent circumferential nanofiber alignment could be achieved in the 3-D nanofibrous PCL tubular scaffolds. The nanofibrous tubular scaffolds with oriented nanofibers had not only directional mechanical property but also could facilitate the orientation of the endothelial cell attachment on the fibers. Multiple layers of aligned nanofibers in different orientations can produce 3-D nanofibrous tubular scaffolds of different macroscopic properties. PMID:20890639

  17. Ornamenting 3D printed scaffolds with cell-laid extracellular matrix for bone tissue regeneration.

    PubMed

    Pati, Falguni; Song, Tae-Ha; Rijal, Girdhari; Jang, Jinah; Kim, Sung Won; Cho, Dong-Woo

    2015-01-01

    3D printing technique is the most sophisticated technique to produce scaffolds with tailorable physical properties. But, these scaffolds often suffer from limited biological functionality as they are typically made from synthetic materials. Cell-laid mineralized ECM was shown to be potential for improving the cellular responses and drive osteogenesis of stem cells. Here, we intend to improve the biological functionality of 3D-printed synthetic scaffolds by ornamenting them with cell-laid mineralized extracellular matrix (ECM) that mimics a bony microenvironment. We developed bone graft substitutes by using 3D printed scaffolds made from a composite of polycaprolactone (PCL), poly(lactic-co-glycolic acid) (PLGA), and β-tricalcium phosphate (β-TCP) and mineralized ECM laid by human nasal inferior turbinate tissue-derived mesenchymal stromal cells (hTMSCs). A rotary flask bioreactor was used to culture hTMSCs on the scaffolds to foster formation of mineralized ECM. A freeze/thaw cycle in hypotonic buffer was used to efficiently decellularize (97% DNA reduction) the ECM-ornamented scaffolds while preserving its main organic and inorganic components. The ECM-ornamented 3D printed scaffolds supported osteoblastic differentiation of newly-seeded hTMSCs by upregulating four typical osteoblastic genes (4-fold higher RUNX2; 3-fold higher ALP; 4-fold higher osteocalcin; and 4-fold higher osteopontin) and increasing calcium deposition compared to bare 3D printed scaffolds. In vivo, in ectopic and orthotopic models in rats, ECM-ornamented scaffolds induced greater bone formation than that of bare scaffolds. These results suggest a valuable method to produce ECM-ornamented 3D printed scaffolds as off-the-shelf bone graft substitutes that combine tunable physical properties with physiological presentation of biological signals.

  18. A Mechanistic Study of Wetting Superhydrophobic Porous 3D Meshes.

    PubMed

    Yohe, Stefan T; Freedman, Jonathan D; Falde, Eric J; Colson, Yolonda L; Grinstaff, Mark W

    2013-08-01

    Superhydrophobic, porous, 3D materials composed of poly( ε -caprolactone) (PCL) and the hydrophobic polymer dopant poly(glycerol monostearate- co - ε -caprolactone) (PGC-C18) are fabricated using the electrospinning technique. These 3D materials are distinct from 2D superhydrophobic surfaces, with maintenance of air at the surface as well as within the bulk of the material. These superhydrophobic materials float in water, and when held underwater and pressed, an air bubble is released and will rise to the surface. By changing the PGC-C18 doping concentration in the meshes and/or the fiber size from the micro- to nanoscale, the long-term stability of the entrapped air layer is controlled. The rate of water infiltration into the meshes, and the resulting displacement of the entrapped air, is quantitatively measured using X-ray computed tomography. The properties of the meshes are further probed using surfactants and solvents of different surface tensions. Finally, the application of hydraulic pressure is used to quantify the breakthrough pressure to wet the meshes. The tools for fabrication and analysis of these superhydrophobic materials as well as the ability to control the robustness of the entrapped air layer are highly desirable for a number of existing and emerging applications. PMID:25309305

  19. 3D fibre deposition and stereolithography techniques for the design of multifunctional nanocomposite magnetic scaffolds.

    PubMed

    De Santis, Roberto; D'Amora, Ugo; Russo, Teresa; Ronca, Alfredo; Gloria, Antonio; Ambrosio, Luigi

    2015-10-01

    Magnetic nanocomposite scaffolds based on poly(ε-caprolactone) and poly(ethylene glycol) were fabricated by 3D fibre deposition modelling (FDM) and stereolithography techniques. In addition, hybrid coaxial and bilayer magnetic scaffolds were produced by combining such techniques. The aim of the current research was to analyse some structural and functional features of 3D magnetic scaffolds obtained by the 3D fibre deposition technique and by stereolithography as well as features of multimaterial scaffolds in the form of coaxial and bilayer structures obtained by the proper integration of such methods. The compressive mechanical behaviour of these scaffolds was investigated in a wet environment at 37 °C, and the morphological features were analysed through scanning electron microscopy (SEM) and X-ray micro-computed tomography. The capability of a magnetic scaffold to absorb magnetic nanoparticles (MNPs) in water solution was also assessed. confocal laser scanning microscopy was used to assess the in vitro biological behaviour of human mesenchymal stem cells (hMSCs) seeded on 3D structures. Results showed that a wide range of mechanical properties, covering those spanning hard and soft tissues, can be obtained by 3D FDM and stereolithography techniques. 3D virtual reconstruction and SEM showed the precision with which the scaffolds were fabricated, and a good-quality interface between poly(ε-caprolactone) and poly(ethylene glycol) based scaffolds was observed for bilayer and coaxial scaffolds. Magnetised scaffolds are capable of absorbing water solution of MNPs, and a preliminary information on cell adhesion and spreading of hMSCs was obtained without the application of an external magnetic field.

  20. 3D fibre deposition and stereolithography techniques for the design of multifunctional nanocomposite magnetic scaffolds.

    PubMed

    De Santis, Roberto; D'Amora, Ugo; Russo, Teresa; Ronca, Alfredo; Gloria, Antonio; Ambrosio, Luigi

    2015-10-01

    Magnetic nanocomposite scaffolds based on poly(ε-caprolactone) and poly(ethylene glycol) were fabricated by 3D fibre deposition modelling (FDM) and stereolithography techniques. In addition, hybrid coaxial and bilayer magnetic scaffolds were produced by combining such techniques. The aim of the current research was to analyse some structural and functional features of 3D magnetic scaffolds obtained by the 3D fibre deposition technique and by stereolithography as well as features of multimaterial scaffolds in the form of coaxial and bilayer structures obtained by the proper integration of such methods. The compressive mechanical behaviour of these scaffolds was investigated in a wet environment at 37 °C, and the morphological features were analysed through scanning electron microscopy (SEM) and X-ray micro-computed tomography. The capability of a magnetic scaffold to absorb magnetic nanoparticles (MNPs) in water solution was also assessed. confocal laser scanning microscopy was used to assess the in vitro biological behaviour of human mesenchymal stem cells (hMSCs) seeded on 3D structures. Results showed that a wide range of mechanical properties, covering those spanning hard and soft tissues, can be obtained by 3D FDM and stereolithography techniques. 3D virtual reconstruction and SEM showed the precision with which the scaffolds were fabricated, and a good-quality interface between poly(ε-caprolactone) and poly(ethylene glycol) based scaffolds was observed for bilayer and coaxial scaffolds. Magnetised scaffolds are capable of absorbing water solution of MNPs, and a preliminary information on cell adhesion and spreading of hMSCs was obtained without the application of an external magnetic field. PMID:26420041

  1. An approach in developing 3D fiber-deposited magnetic scaffolds for tissue engineering

    SciTech Connect

    De Santis, R.; Gloria, A.; D'Amora, U.; Zeppetelli, S.; Ambrosio, L.; Russo, T.

    2010-06-02

    Scaffolds should possess suitable properties to play their specific role. In this work, the potential of 3D fiber deposition technique to develop multifunctional and well-defined magnetic poly(epsilon-caprolactone)/iron oxide scaffolds has been highlighted, and the effect of iron oxide nanoparticles on the biological and mechanical performances has been assessed.

  2. Physical modification of the interior surfaces of PLGA porous scaffolds using sugar fibers as template.

    PubMed

    Qu, Zehua; Ding, Jiandong

    2013-01-01

    A three-dimensional (3D) poly(D,L-lactic-co-glycolic acid) porous scaffold with microgrooves and microholes on the pore walls was fabricated by using salt particulates as main porogens and sugar fibers as modifiers. Besides macropores templated from salt particulates, microgrooves and microholes were generated after leaching sugar fibers. The resultant porous scaffolds were of high porosity over 90% and still kept good mechanical properties. The microgrooves were globally randomly distributed, but locally anisotropic, resulting in contact guidance of cells, and an appropriate fraction of fibers in fabrication of 3D scaffolds led to a significantly enhanced cell viability; the microholes increased the loading amount of a model protein bovine serum albumin. Two key ideal parameters of this technical strategy, the full coverage amount of sugar fibers on the salt particulates, m(c), and the ratio of the surface areas of modified and unmodified scaffolds S(in)=S(in,o) were defined and derived.

  3. Evaluating 3D-printed biomaterials as scaffolds for vascularized bone tissue engineering.

    PubMed

    Wang, Martha O; Vorwald, Charlotte E; Dreher, Maureen L; Mott, Eric J; Cheng, Ming-Huei; Cinar, Ali; Mehdizadeh, Hamidreza; Somo, Sami; Dean, David; Brey, Eric M; Fisher, John P

    2015-01-01

    There is an unmet need for a consistent set of tools for the evaluation of 3D-printed constructs. A toolbox developed to design, characterize, and evaluate 3D-printed poly(propylene fumarate) scaffolds is proposed for vascularized engineered tissues. This toolbox combines modular design and non-destructive fabricated design evaluation, evaluates biocompatibility and mechanical properties, and models angiogenesis.

  4. Systematical Evaluation of Mechanically Strong 3D Printed Diluted magnesium Doping Wollastonite Scaffolds on Osteogenic Capacity in Rabbit Calvarial Defects

    PubMed Central

    Sun, Miao; Liu, An; Shao, Huifeng; Yang, Xianyan; Ma, Chiyuan; Yan, Shigui; Liu, Yanming; He, Yong; Gou, Zhongru

    2016-01-01

    Wollastonite (CaSiO3; CSi) ceramic is a promising bioactive material for bone defect repair due to slightly fast degradation of its porous constructs in vivo. In our previous strategy some key features of CSi ceramic have been significantly improved by dilute magnesium doping for regulating mechanical properties and biodegradation. Here we demonstrate that 6 ~ 14% of Ca substituted by Mg in CSi (CSi-Mgx, x = 6, 10, 14) can enhance the mechanical strength (>40 MPa) but not compromise biological performances of the 3D printed porous scaffolds with open porosity of 60‒63%. The in vitro cell culture tests in vitro indicated that the dilute Mg doping into CSi was beneficial for ALP activity and high expression of osteogenic marker genes of MC3T3-E1 cells in the scaffolds. A good bone tissue regeneration response and elastoplastic response in mechanical strength in vivo were determined after implantation in rabbit calvarial defects for 6‒12 weeks. Particularly, the CSi-Mg10 and CSi-Mg14 scaffolds could enhance new bone regeneration with a significant increase of newly formed bone tissue (18 ~ 22%) compared to the pure CSi (~14%) at 12 weeks post-implantation. It is reasonable to consider that, therefore, such CSi-Mgx scaffolds possessing excellent strength and reasonable degradability are promising for bone reconstruction in thin-wall bone defects. PMID:27658481

  5. Osteogenic cell response to 3-D hydroxyapatite scaffolds developed via replication of natural marine sponges.

    PubMed

    Clarke, S A; Choi, S Y; McKechnie, Melanie; Burke, G; Dunne, N; Walker, G; Cunningham, E; Buchanan, F

    2016-02-01

    Bone tissue engineering may provide an alternative to autograft, however scaffold optimisation is required to maximize bone ingrowth. In designing scaffolds, pore architecture is important and there is evidence that cells prefer a degree of non-uniformity. The aim of this study was to compare scaffolds derived from a natural porous marine sponge (Spongia agaricina) with unique architecture to those derived from a synthetic polyurethane foam. Hydroxyapatite scaffolds of 1 cm(3) were prepared via ceramic infiltration of a marine sponge and a polyurethane (PU) foam. Human foetal osteoblasts (hFOB) were seeded at 1 × 10(5) cells/scaffold for up to 14 days. Cytotoxicity, cell number, morphology and differentiation were investigated. PU-derived scaffolds had 84-91% porosity and 99.99% pore interconnectivity. In comparison marine sponge-derived scaffolds had 56-61% porosity and 99.9% pore interconnectivity. hFOB studies showed that a greater number of cells were found on marine sponge-derived scaffolds at than on the PU scaffold but there was no significant difference in cell differentiation. X-ray diffraction and inductively coupled plasma mass spectrometry showed that Si ions were released from the marine-derived scaffold. In summary, three dimensional porous constructs have been manufactured that support cell attachment, proliferation and differentiation but significantly more cells were seen on marine-derived scaffolds. This could be due both to the chemistry and pore architecture of the scaffolds with an additional biological stimulus from presence of Si ions. Further in vivo tests in orthotopic models are required but this marine-derived scaffold shows promise for applications in bone tissue engineering. PMID:26704539

  6. Bioengineered silk scaffolds in 3D tissue modeling with focus on mammary tissues.

    PubMed

    Maghdouri-White, Yas; Bowlin, Gary L; Lemmon, Christopher A; Dréau, Didier

    2016-02-01

    In vitro generation of three-dimensional (3D) biological tissues and organ-like structures is a promising strategy to study and closely model complex aspects of the molecular, cellular, and physiological interactions of tissue. In particular, in vitro 3D tissue modeling holds promises to further our understanding of breast development. Indeed, biologically relevant 3D structures that combine mammary cells and engineered matrices have improved our knowledge of mammary tissue growth, organization, and differentiation. Several polymeric biomaterials have been used as scaffolds to engineer 3D mammary tissues. Among those, silk fibroin-based biomaterials have many biologically relevant properties and have been successfully used in multiple medical applications. Here, we review the recent advances in engineered scaffolds with an emphasis on breast-like tissue generation and the benefits of modified silk-based scaffolds.

  7. Fabrication of a customized bone scaffold using a homemade medical 3D printer for comminuted fractures

    NASA Astrophysics Data System (ADS)

    Yoon, Do-Kun; Jung, Joo-Young; Shin, Han-Back; Kim, Moo-Sub; Choe, Bo-Young; Kim, Sunmi; Suh, Tae Suk; Lee, Keum Sil; Xing, Lei

    2016-09-01

    The purpose of this study was to show a 3D printed reconstruction model of a bone destroyed by a comminuted fracture. After a thoracic limb of a cow with a comminuted fracture was scanned by using computed tomography, a scaffold was designed by using a 3D modeling tool for its reconstruction and fabricated by using a homemade medical 3D printer. The homemade medical 3D printer was designed for medical use. In order to reconstruct the geometry of the destroyed bone, we use the geometry of a similar section (reference geometry) of normal bone in the 3D modeling process. The missing part between the destroyed ridge and the reference geometry was filled with an effective space by using a manual interpolation. Inexpensive materials and free software were used to construct the medical 3D printer system. The fabrication of the scaffold progressed according to the design of reconstructed bone by using this medical 3D printer. The material of the scaffold was biodegradable material, and could be transplanted into the human body. The fabricated scaffold was correctly inserted into the fractured bone in place of the destroyed portion, with good agreement. According to physical stress test results, the performance of printing resolution was 0.1 mm. The average geometrical error of the scaffold was below 0.3 mm. The reconstructed bone by using the fabricated scaffold was able to support the weight of the human body. No process used to obtain the result was complex or required many resources. The methods and results in this study show several possible clinical applications in fields such as orthopedics or oncology without a need to purchase high-price instruments for 3D printing.

  8. Porous titanium scaffolds fabricated using a rapid prototyping and powder metallurgy technique.

    PubMed

    Ryan, Garrett E; Pandit, Abhay S; Apatsidis, Dimitrios P

    2008-09-01

    One of the main issues in orthopaedic implant design is the fabrication of scaffolds that closely mimic the biomechanical properties of the surrounding bone. This research reports on a multi-stage rapid prototyping technique that was successfully developed to produce porous titanium scaffolds with fully interconnected pore networks and reproducible porosity and pore size. The scaffolds' porous characteristics were governed by a sacrificial wax template, fabricated using a commercial 3D-printer. Powder metallurgy processes were employed to generate the titanium scaffolds by filling around the wax template with titanium slurry. In the attempt to optimise the powder metallurgy technique, variations in slurry concentration, compaction pressure and sintering temperature were investigated. By altering the wax design template, pore sizes ranging from 200 to 400 microm were achieved. Scaffolds with porosities of 66.8 +/- 3.6% revealed compression strengths of 104.4+/-22.5 MPa in the axial direction and 23.5 +/- 9.6 MPa in the transverse direction demonstrating their anisotropic nature. Scaffold topography was characterised using scanning electron microscopy and microcomputed tomography. Three-dimensional reconstruction enabled the main architectural parameters such as pore size, interconnecting porosity, level of anisotropy and level of structural disorder to be determined. The titanium scaffolds were compared to their intended designs, as governed by their sacrificial wax templates. Although discrepancies in architectural parameters existed between the intended and the actual scaffolds, overall the results indicate that the porous titanium scaffolds have the properties to be potentially employed in orthopaedic applications.

  9. Mechanical Improvements to Reinforced Porous Silk Scaffolds

    PubMed Central

    Gil, Eun Seok; Kluge, Jonathan A.; Rockwood, Danielle N.; Rajkhowa, Rangam; Wang, Lijing; Wang, Xungai; Kaplan, David L

    2012-01-01

    Load bearing porous biodegradable scaffolds are required to engineer functional tissues such as bone. Mechanical improvements to porogen leached scaffolds prepared from silk proteins were systematically studied through the addition of silk particles in combination with silk solution concentration, exploiting interfacial compatibility between the two components. Solvent solutions of silk up to 32 w/v% were successfully prepared in hexafluoroisopropanaol (HFIP) for the study. The mechanical properties of the reinforced silk scaffolds correlated to the material density and matched by a power law relationship, independent of the ratio of silk particles to matrix. These results were similar to the relationships previously shown for cancellous bone. The mechanism behind the increased mechanical properties was a densification effect, and not the effect of including stiffer silk particles into the softer silk continuous matrix. A continuous interface between the silk matrix and the silk particles, as well as homogeneous distribution of the silk particles within the matrix were observed. Furthermore, we note that the roughness of the pore walls was controllable by varying the ratio of particles matrix, providing a route to control topography. The rate of proteolytic hydrolysis of the scaffolds decreased with increase in mass of silk used in the matrix and with increasing silk particle content. PMID:21793193

  10. 3D-Printed ABS and PLA Scaffolds for Cartilage and Nucleus Pulposus Tissue Regeneration.

    PubMed

    Rosenzweig, Derek H; Carelli, Eric; Steffen, Thomas; Jarzem, Peter; Haglund, Lisbet

    2015-07-03

    Painful degeneration of soft tissues accounts for high socioeconomic costs. Tissue engineering aims to provide biomimetics recapitulating native tissues. Biocompatible thermoplastics for 3D printing can generate high-resolution structures resembling tissue extracellular matrix. Large-pore 3D-printed acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) scaffolds were compared for cell ingrowth, viability, and tissue generation. Primary articular chondrocytes and nucleus pulposus (NP) cells were cultured on ABS and PLA scaffolds for three weeks. Both cell types proliferated well, showed high viability, and produced ample amounts of proteoglycan and collagen type II on both scaffolds. NP generated more matrix than chondrocytes; however, no difference was observed between scaffold types. Mechanical testing revealed sustained scaffold stability. This study demonstrates that chondrocytes and NP cells can proliferate on both ABS and PLA scaffolds printed with a simplistic, inexpensive desktop 3D printer. Moreover, NP cells produced more proteoglycan than chondrocytes, irrespective of thermoplastic type, indicating that cells maintain individual phenotype over the three-week culture period. Future scaffold designs covering larger pore sizes and better mimicking native tissue structure combined with more flexible or resorbable materials may provide implantable constructs with the proper structure, function, and cellularity necessary for potential cartilage and disc tissue repair in vivo.

  11. 3D-Printed ABS and PLA Scaffolds for Cartilage and Nucleus Pulposus Tissue Regeneration

    PubMed Central

    Rosenzweig, Derek H.; Carelli, Eric; Steffen, Thomas; Jarzem, Peter; Haglund, Lisbet

    2015-01-01

    Painful degeneration of soft tissues accounts for high socioeconomic costs. Tissue engineering aims to provide biomimetics recapitulating native tissues. Biocompatible thermoplastics for 3D printing can generate high-resolution structures resembling tissue extracellular matrix. Large-pore 3D-printed acrylonitrile butadiene styrene (ABS) and polylactic acid (PLA) scaffolds were compared for cell ingrowth, viability, and tissue generation. Primary articular chondrocytes and nucleus pulposus (NP) cells were cultured on ABS and PLA scaffolds for three weeks. Both cell types proliferated well, showed high viability, and produced ample amounts of proteoglycan and collagen type II on both scaffolds. NP generated more matrix than chondrocytes; however, no difference was observed between scaffold types. Mechanical testing revealed sustained scaffold stability. This study demonstrates that chondrocytes and NP cells can proliferate on both ABS and PLA scaffolds printed with a simplistic, inexpensive desktop 3D printer. Moreover, NP cells produced more proteoglycan than chondrocytes, irrespective of thermoplastic type, indicating that cells maintain individual phenotype over the three-week culture period. Future scaffold designs covering larger pore sizes and better mimicking native tissue structure combined with more flexible or resorbable materials may provide implantable constructs with the proper structure, function, and cellularity necessary for potential cartilage and disc tissue repair in vivo. PMID:26151846

  12. 3D Bioprinting Using a Templated Porous Bioink.

    PubMed

    Armstrong, James P K; Burke, Madeline; Carter, Benjamin M; Davis, Sean A; Perriman, Adam W

    2016-07-01

    3D tissue printing with adult stem cells is reported. A novel cell-containing multicomponent bioink is used in a two-step 3D printing process to engineer bone and cartilage architectures. PMID:27125336

  13. Subacute Tissue Response to 3D Graphene Oxide Scaffolds Implanted in the Injured Rat Spinal Cord.

    PubMed

    López-Dolado, Elisa; González-Mayorga, Ankor; Portolés, María Teresa; Feito, María José; Ferrer, María Luisa; Del Monte, Francisco; Gutiérrez, María Concepción; Serrano, María Concepción

    2015-08-26

    The increasing prevalence and high sanitary costs of lesions affecting the central nervous system (CNS) at the spinal cord are encouraging experts in different fields to explore new avenues for neural repair. In this context, graphene and its derivatives are attracting significant attention, although their toxicity and performance in the CNS in vivo remains unclear. Here, the subacute tissue response to 3D flexible and porous scaffolds composed of partially reduced graphene oxide is investigated when implanted in the injured rat spinal cord. The interest of these structures as potentially useful platforms for CNS regeneration mainly relies on their mechanical compliance with neural tissues, adequate biocompatibility with neural cells in vitro and versatility to carry topographical and biological guidance cues. Early tissue responses are thoroughly investigated locally (spinal cord at C6 level) and in the major organs (i.e., kidney, liver, lung, and spleen). The absence of local and systemic toxic responses, along with the positive signs found at the lesion site (e.g., filler effect, soft interface for no additional scaring, preservation of cell populations at the perilesional area, presence of M2 macrophages), encourages further investigation of these materials as promising components of more efficient material-based platforms for CNS repair.

  14. Design of a Novel 3D Printed Bioactive Nanocomposite Scaffold for Improved Osteochondral Regeneration

    PubMed Central

    Castro, Nathan J.; Patel, Romil; Zhang, Lijie Grace

    2015-01-01

    Chronic and acute osteochondral defects as a result of osteoarthritis and trauma present a common and serious clinical problem due to the tissue's inherent complexity and poor regenerative capacity. In addition, cells within the osteochondral tissue are in intimate contact with a 3D nanostructured extracellular matrix composed of numerous bioactive organic and inorganic components. As an emerging manufacturing technique, 3D printing offers great precision and control over the microarchitecture, shape and composition of tissue scaffolds. Therefore, the objective of this study is to develop a biomimetic 3D printed nanocomposite scaffold with integrated differentiation cues for improved osteochondral tissue regeneration. Through the combination of novel nano-inks composed of organic and inorganic bioactive factors and advanced 3D printing, we have successfully fabricated a series of novel constructs which closely mimic the native 3D extracellular environment with hierarchical nanoroughness, microstructure and spatiotemporal bioactive cues. Our results illustrate several key characteristics of the 3D printed nanocomposite scaffold to include improved mechanical properties as well as excellent cytocompatibility for enhanced human bone marrow-derived mesenchymal stem cell adhesion, proliferation, and osteochondral differentiation in vitro. The present work further illustrates the effectiveness of the scaffolds developed here as a promising and highly tunable platform for osteochondral tissue regeneration. PMID:26366231

  15. Mechanical evaluation of gradient electrospun scaffolds with 3D printed ring reinforcements for tracheal defect repair.

    PubMed

    Ott, Lindsey M; Zabel, Taylor A; Walker, Natalie K; Farris, Ashley L; Chakroff, Jason T; Ohst, Devan G; Johnson, Jed K; Gehrke, Steven H; Weatherly, Robert A; Detamore, Michael S

    2016-04-01

    Tracheal stenosis can become a fatal condition, and current treatments include augmentation of the airway with autologous tissue. A tissue-engineered approach would not require a donor source, while providing an implant that meets both surgeons' and patients' needs. A fibrous, polymeric scaffold organized in gradient bilayers of polycaprolactone (PCL) and poly-lactic-co-glycolic acid (PLGA) with 3D printed structural ring supports, inspired by the native trachea rings, could meet this need. The purpose of the current study was to characterize the tracheal scaffolds with mechanical testing models to determine the design most suitable for maintaining a patent airway. Degradation over 12 weeks revealed that scaffolds with the 3D printed rings had superior properties in tensile and radial compression, with at least a three fold improvement and 8.5-fold improvement, respectively, relative to the other scaffold groups. The ringed scaffolds produced tensile moduli, radial compressive forces, and burst pressures similar to or exceeding physiological forces and native tissue data. Scaffolds with a thicker PCL component had better suture retention and tube flattening recovery properties, with the monolayer of PCL (PCL-only group) exhibiting a 2.3-fold increase in suture retention strength (SRS). Tracheal scaffolds with ring reinforcements have improved mechanical properties, while the fibrous component increased porosity and cell infiltration potential. These scaffolds may be used to treat various trachea defects (patch or circumferential) and have the potential to be employed in other tissue engineering applications. PMID:27097554

  16. In-vivo behavior of Si-hydroxyapatite/polycaprolactone/DMB scaffolds fabricated by 3D printing.

    PubMed

    Meseguer-Olmo, Luis; Vicente-Ortega, Vicente; Alcaraz-Baños, Miguel; Calvo-Guirado, José Luis; Vallet-Regí, María; Arcos, Daniel; Baeza, Alejandro

    2013-07-01

    Scaffolds made of polycaprolactone and nanocrystalline silicon-substituted hydroxyapatite have been fabricated by 3D printing rapid prototyping technique. To asses that the scaffolds fulfill the requirements to be considered for bone grafting applications, they were implanted in New Zealand rabbits. Histological and radiological studies have demonstrated that the scaffolds implanted in bone exhibited an excellent osteointegration without the interposition of fibrous tissue between bone and implants and without immune response after 4 months of implantation. In addition, we have evaluated the possibility of improving the scaffolds efficiency by incorporating demineralized bone matrix during the preparation by 3D printing. When demineralized bone matrix (DBM) is incorporated, the efficacy of the scaffolds is enhanced, as new bone formation occurs not only in the peripheral portions of the scaffolds but also within its pores after 4 months of implantation. This enhanced performance can be explained in terms of the osteoinductive properties of the DBM in the scaffolds, which have been assessed through the new bone tissue formation when the scaffolds are ectopically implanted.

  17. Construction of a 3D rGO-collagen hybrid scaffold for enhancement of the neural differentiation of mesenchymal stem cells

    NASA Astrophysics Data System (ADS)

    Guo, Weibo; Wang, Shu; Yu, Xin; Qiu, Jichuan; Li, Jianhua; Tang, Wei; Li, Zhou; Mou, Xiaoning; Liu, Hong; Wang, Zhonglin

    2016-01-01

    The cell-material interface is one of the most important considerations in designing a high-performance tissue engineering scaffold because the surface of the scaffold can determine the fate of stem cells. A conductive surface is required for a scaffold to direct stem cells toward neural differentiation. However, most conductive polymers are toxic and not amenable to biological degradation, which restricts the design of neural tissue engineering scaffolds. In this study, we used a bioactive three-dimensional (3D) porcine acellular dermal matrix (PADM), which is mainly composed of type I collagen, as a basic material and successfully assembled a layer of reduced graphene oxide (rGO) nanosheets on the surface of the PADM channels to obtain a porous 3D, biodegradable, conductive and biocompatible PADM-rGO hybrid neural tissue engineering scaffold. Compared with the PADM scaffold, assembling the rGO into the scaffold did not induce a significant change in the microstructure but endowed the PADM-rGO hybrid scaffold with good conductivity. A comparison of the neural differentiation of rat bone-marrow-derived mesenchymal stem cells (MSCs) was performed by culturing the MSCs on PADM and PADM-rGO scaffolds in neuronal culture medium, followed by the determination of gene expression and immunofluorescence staining. The results of both the gene expression and protein level assessments suggest that the rGO-assembled PADM scaffold may promote the differentiation of MSCs into neuronal cells with higher protein and gene expression levels after 7 days under neural differentiation conditions. This study demonstrated that the PADM-rGO hybrid scaffold is a promising scaffold for neural tissue engineering; this scaffold can not only support the growth of MSCs at a high proliferation rate but also enhance the differentiation of MSCs into neural cells.The cell-material interface is one of the most important considerations in designing a high-performance tissue engineering scaffold

  18. Metabolic alteration of HepG2 in scaffold-based 3-D culture: proteomic approach.

    PubMed

    Pruksakorn, Dumnoensun; Lirdprapamongkol, Kriengsak; Chokchaichamnankit, Daranee; Subhasitanont, Pantipa; Chiablaem, Khajeelak; Svasti, Jisnuson; Srisomsap, Chantragan

    2010-11-01

    3-D cell culture models are important in cancer biology since they provide improved understanding of tumor microenvironment. We have established a 3-D culture model using HepG2 in natural collagen-based scaffold to mimic the development of small avascular tumor in vivo. Morphological characterization showed that HepG2 colonies grew within the interior of the scaffold and showed enhanced extracellular matrix deposition. High levels of cell proliferation in the outermost regions of the scaffold created a hypoxic microenvironment in the 3-D culture system, as indicated by hypoxia-inducible factor-1α stabilization, detectable by Western blotting and immunohistochemistry. Proteomic studies showed decreased expression of several mitochondrial proteins and increased expression of proteins in anaerobic glycolysis under 3-D culture compared to monolayer culture. Creatine kinase was also upregulated in 3-D culture, indicating its possible role as an important energy buffer system under hypoxic microenvironment. Increased levels of proteins in nucleotide metabolism may relate to cellular energy. Thus, our results suggest that HepG2 cells under 3-D culture adapt their energy metabolism in response to hypoxic conditions. Metabolic alterations in the 3-D culture model may relate to physiological changes relevant to development of small avascular tumor in vivo and their study may improve future therapeutic strategies.

  19. Composite lithium metal anode by melt infusion of lithium into a 3D conducting scaffold with lithiophilic coating

    PubMed Central

    Liang, Zheng; Lin, Dingchang; Zhao, Jie; Lu, Zhenda; Liu, Yayuan; Liu, Chong; Lu, Yingying; Wang, Haotian; Yan, Kai; Tao, Xinyong; Cui, Yi

    2016-01-01

    Lithium metal-based battery is considered one of the best energy storage systems due to its high theoretical capacity and lowest anode potential of all. However, dendritic growth and virtually relative infinity volume change during long-term cycling often lead to severe safety hazards and catastrophic failure. Here, a stable lithium–scaffold composite electrode is developed by lithium melt infusion into a 3D porous carbon matrix with “lithiophilic” coating. Lithium is uniformly entrapped on the matrix surface and in the 3D structure. The resulting composite electrode possesses a high conductive surface area and excellent structural stability upon galvanostatic cycling. We showed stable cycling of this composite electrode with small Li plating/stripping overpotential (<90 mV) at a high current density of 3 mA/cm2 over 80 cycles. PMID:26929378

  20. Construction of a 3D rGO-collagen hybrid scaffold for enhancement of the neural differentiation of mesenchymal stem cells.

    PubMed

    Guo, Weibo; Wang, Shu; Yu, Xin; Qiu, Jichuan; Li, Jianhua; Tang, Wei; Li, Zhou; Mou, Xiaoning; Liu, Hong; Wang, Zhonglin

    2016-01-28

    The cell-material interface is one of the most important considerations in designing a high-performance tissue engineering scaffold because the surface of the scaffold can determine the fate of stem cells. A conductive surface is required for a scaffold to direct stem cells toward neural differentiation. However, most conductive polymers are toxic and not amenable to biological degradation, which restricts the design of neural tissue engineering scaffolds. In this study, we used a bioactive three-dimensional (3D) porcine acellular dermal matrix (PADM), which is mainly composed of type I collagen, as a basic material and successfully assembled a layer of reduced graphene oxide (rGO) nanosheets on the surface of the PADM channels to obtain a porous 3D, biodegradable, conductive and biocompatible PADM-rGO hybrid neural tissue engineering scaffold. Compared with the PADM scaffold, assembling the rGO into the scaffold did not induce a significant change in the microstructure but endowed the PADM-rGO hybrid scaffold with good conductivity. A comparison of the neural differentiation of rat bone-marrow-derived mesenchymal stem cells (MSCs) was performed by culturing the MSCs on PADM and PADM-rGO scaffolds in neuronal culture medium, followed by the determination of gene expression and immunofluorescence staining. The results of both the gene expression and protein level assessments suggest that the rGO-assembled PADM scaffold may promote the differentiation of MSCs into neuronal cells with higher protein and gene expression levels after 7 days under neural differentiation conditions. This study demonstrated that the PADM-rGO hybrid scaffold is a promising scaffold for neural tissue engineering; this scaffold can not only support the growth of MSCs at a high proliferation rate but also enhance the differentiation of MSCs into neural cells. PMID:26750302

  1. Construction of a 3D rGO-collagen hybrid scaffold for enhancement of the neural differentiation of mesenchymal stem cells.

    PubMed

    Guo, Weibo; Wang, Shu; Yu, Xin; Qiu, Jichuan; Li, Jianhua; Tang, Wei; Li, Zhou; Mou, Xiaoning; Liu, Hong; Wang, Zhonglin

    2016-01-28

    The cell-material interface is one of the most important considerations in designing a high-performance tissue engineering scaffold because the surface of the scaffold can determine the fate of stem cells. A conductive surface is required for a scaffold to direct stem cells toward neural differentiation. However, most conductive polymers are toxic and not amenable to biological degradation, which restricts the design of neural tissue engineering scaffolds. In this study, we used a bioactive three-dimensional (3D) porcine acellular dermal matrix (PADM), which is mainly composed of type I collagen, as a basic material and successfully assembled a layer of reduced graphene oxide (rGO) nanosheets on the surface of the PADM channels to obtain a porous 3D, biodegradable, conductive and biocompatible PADM-rGO hybrid neural tissue engineering scaffold. Compared with the PADM scaffold, assembling the rGO into the scaffold did not induce a significant change in the microstructure but endowed the PADM-rGO hybrid scaffold with good conductivity. A comparison of the neural differentiation of rat bone-marrow-derived mesenchymal stem cells (MSCs) was performed by culturing the MSCs on PADM and PADM-rGO scaffolds in neuronal culture medium, followed by the determination of gene expression and immunofluorescence staining. The results of both the gene expression and protein level assessments suggest that the rGO-assembled PADM scaffold may promote the differentiation of MSCs into neuronal cells with higher protein and gene expression levels after 7 days under neural differentiation conditions. This study demonstrated that the PADM-rGO hybrid scaffold is a promising scaffold for neural tissue engineering; this scaffold can not only support the growth of MSCs at a high proliferation rate but also enhance the differentiation of MSCs into neural cells.

  2. 3D printed PLA-based scaffolds: a versatile tool in regenerative medicine.

    PubMed

    Serra, Tiziano; Mateos-Timoneda, Miguel A; Planell, Josep A; Navarro, Melba

    2013-10-01

    Rapid prototyping (RP), also known as additive manufacturing (AM), has been well received and adopted in the biomedical field. The capacity of this family of techniques to fabricate customized 3D structures with complex geometries and excellent reproducibility has revolutionized implantology and regenerative medicine. In particular, nozzle-based systems allow the fabrication of high-resolution polylactic acid (PLA) structures that are of interest in regenerative medicine. These 3D structures find interesting applications in the regenerative medicine field where promising applications including biodegradable templates for tissue regeneration purposes, 3D in vitro platforms for studying cell response to different scaffolds conditions and for drug screening are considered among others. Scaffolds functionality depends not only on the fabrication technique, but also on the material used to build the 3D structure, the geometry and inner architecture of the structure, and the final surface properties. All being crucial parameters affecting scaffolds success. This Commentary emphasizes the importance of these parameters in scaffolds' fabrication and also draws the attention toward the versatility of these PLA scaffolds as a potential tool in regenerative medicine and other medical fields.

  3. Chitosan-based hydrogel tissue scaffolds made by 3D plotting promotes osteoblast proliferation and mineralization.

    PubMed

    Liu, I-Hsin; Chang, Shih-Hsin; Lin, Hsin-Yi

    2015-05-13

    A 3D plotting system was used to make chitosan-based tissue scaffolds with interconnected pores using pure chitosan (C) and chitosan cross-linked with pectin (CP) and genipin (CG). A freeze-dried chitosan scaffold (CF/D) was made to compare with C, to observe the effects of structural differences. The fiber size, pore size, porosity, compression strength, swelling ratio, drug release efficacy, and cumulative weight loss of the scaffolds were measured. Osteoblasts were cultured on the scaffolds and their proliferation, type I collagen production, alkaline phosphatase activity, calcium deposition, and morphology were observed. C had a lower swelling ratio, degradation, porosity and drug release efficacy and a higher compressional stiffness and cell proliferation compared to CF/D (p < 0.05). Of the 3D-plotted samples, cells on CP exhibited the highest degree of mineralization after 21 d (p < 0.05). CP also had the highest swelling ratio and fastest drug release, followed by C and CG (p < 0.05). Both CP and CG were stiffer and degraded more slowly in saline solution than C (p < 0.05). In summary, 3D-plotted scaffolds were stronger, less likely to degrade and better promoted osteoblast cell proliferation in vitro compared to the freeze-dried scaffolds. C, CP and CG were structurally similar, and the different crosslinking caused significant changes in their physical and biological performances.

  4. Development of melt electrohydrodynamic 3D printing for complex microscale poly (ε-caprolactone) scaffolds.

    PubMed

    He, Jiankang; Xia, Peng; Li, Dichen

    2016-01-01

    The replication of native hierarchical structures into synthetic scaffolds is important to direct cell growth and tissue regeneration. However, most of the existing scaffold strategies lack the capability to simultaneously realize the controlled fabrication of macroscopic geometries as well as microscale architectures with the scale similar to living cells. Here we developed a melt electrohydrodynamic printing platform and verified its feasibility to fabricate three-dimensional (3D) tissue-engineered scaffolds with complex curved geometries and microscale fibrous structures. Melting temperature was studied to stably print poly (ε-caprolactone) (PCL) filaments with the size of about 10 μm, which was precisely stacked into 3D straight walls with fine surface quality. By adjusting stage moving speed and directions, 3D PCL scaffolds with curved contours and predefined fiber orientations or spacing were successfully printed. Biological experiments showed that the printed microscale scaffolds had good biocompatibility and facilitated cellular proliferation and alignment in vitro. It is envisioned that the melt electrohydrodynamic printing can potentially provide an innovative tool to fabricate hierarchical scaffolds that mimic the native tissue architectures in a multiscale level. PMID:27490377

  5. Development of melt electrohydrodynamic 3D printing for complex microscale poly (ε-caprolactone) scaffolds.

    PubMed

    He, Jiankang; Xia, Peng; Li, Dichen

    2016-01-01

    The replication of native hierarchical structures into synthetic scaffolds is important to direct cell growth and tissue regeneration. However, most of the existing scaffold strategies lack the capability to simultaneously realize the controlled fabrication of macroscopic geometries as well as microscale architectures with the scale similar to living cells. Here we developed a melt electrohydrodynamic printing platform and verified its feasibility to fabricate three-dimensional (3D) tissue-engineered scaffolds with complex curved geometries and microscale fibrous structures. Melting temperature was studied to stably print poly (ε-caprolactone) (PCL) filaments with the size of about 10 μm, which was precisely stacked into 3D straight walls with fine surface quality. By adjusting stage moving speed and directions, 3D PCL scaffolds with curved contours and predefined fiber orientations or spacing were successfully printed. Biological experiments showed that the printed microscale scaffolds had good biocompatibility and facilitated cellular proliferation and alignment in vitro. It is envisioned that the melt electrohydrodynamic printing can potentially provide an innovative tool to fabricate hierarchical scaffolds that mimic the native tissue architectures in a multiscale level.

  6. Chitosan-based hydrogel tissue scaffolds made by 3D plotting promotes osteoblast proliferation and mineralization.

    PubMed

    Liu, I-Hsin; Chang, Shih-Hsin; Lin, Hsin-Yi

    2015-06-01

    A 3D plotting system was used to make chitosan-based tissue scaffolds with interconnected pores using pure chitosan (C) and chitosan cross-linked with pectin (CP) and genipin (CG). A freeze-dried chitosan scaffold (CF/D) was made to compare with C, to observe the effects of structural differences. The fiber size, pore size, porosity, compression strength, swelling ratio, drug release efficacy, and cumulative weight loss of the scaffolds were measured. Osteoblasts were cultured on the scaffolds and their proliferation, type I collagen production, alkaline phosphatase activity, calcium deposition, and morphology were observed. C had a lower swelling ratio, degradation, porosity and drug release efficacy and a higher compressional stiffness and cell proliferation compared to CF/D (p < 0.05). Of the 3D-plotted samples, cells on CP exhibited the highest degree of mineralization after 21 d (p < 0.05). CP also had the highest swelling ratio and fastest drug release, followed by C and CG (p < 0.05). Both CP and CG were stiffer and degraded more slowly in saline solution than C (p < 0.05). In summary, 3D-plotted scaffolds were stronger, less likely to degrade and better promoted osteoblast cell proliferation in vitro compared to the freeze-dried scaffolds. C, CP and CG were structurally similar, and the different crosslinking caused significant changes in their physical and biological performances. PMID:25970802

  7. Improved osteoblast cell affinity on plasma-modified 3-D extruded PCL scaffolds.

    PubMed

    Domingos, M; Intranuovo, F; Gloria, A; Gristina, R; Ambrosio, L; Bártolo, P J; Favia, P

    2013-04-01

    Cellular adhesion and proliferation inside three-dimensional synthetic scaffolds represent a major challenge in tissue engineering. Besides the surface chemistry of the polymers, it is well recognized that scaffold internal architecture, namely pore size/shape and interconnectivity, has a strong effect on the biological response of cells. This study reports for the first time how polycaprolactone (PCL) scaffolds with controlled micro-architecture can be effectively produced via bioextrusion and used to enhance the penetration of plasma deposited species. Low-pressure nitrogen-based coatings were employed to augment cell adhesion and proliferation without altering the mechanical properties of the structures. X-ray photoelectron spectroscopy carried out on different sections of the scaffolds indicates a uniform distribution of nitrogen-containing groups throughout the entire porous structure. In vitro biological assays confirm that plasma deposition sensitively promotes the activity of Saos-2 osteoblast cells, leading to a homogeneous colonization of the PCL scaffolds.

  8. Development of a 3D polymer reinforced calcium phosphate cement scaffold for cranial bone tissue engineering

    NASA Astrophysics Data System (ADS)

    Alge, Daniel L.

    The repair of critical-sized cranial bone defects represents an important clinical challenge. The limitations of autografts and alloplastic materials make a bone tissue engineering strategy desirable, but success depends on the development of an appropriate scaffold. Key scaffold properties include biocompatibility, osteoconductivity, sufficient strength to maintain its structure, and resorbability. Furthermore, amenability to rapid prototyping fabrication methods is desirable, as these approaches offer precise control over scaffold architecture and have the potential for customization. While calcium phosphate cements meet many of these criteria due to their composition and their injectability, which can be leveraged for scaffold fabrication via indirect casting, their mechanical properties are a major limitation. Thus, the overall goal of this work was to develop a 3D polymer reinforced calcium phosphate cement scaffold for use in cranial bone tissue engineering. Dicalcium phosphate dihydrate (DCPD) setting cements are of particular interest because of their excellent resorbability. We demonstrated for the first time that DCPD cement can be prepared from monocalcium phosphate monohydrate (MCPM)/hydroxyapatite (HA) mixtures. However, subsequent characterization revealed that MCPM/HA cements rapidly convert to HA during degradation, which is undesirable and led us to choose a more conventional formulation for scaffold fabrication. In addition, we developed a novel method for calcium phosphate cement reinforcement that is based on infiltrating a pre-set cement structure with a polymer, and then crosslinking the polymer in situ. Unlike prior methods of cement reinforcement, this method can be applied to the reinforcement of 3D scaffolds fabricated by indirect casting. Using our novel method, composites of poly(propylene fumarate) (PPF) reinforced DCPD were prepared and demonstrated as excellent candidate scaffold materials, as they had increased strength and ductility

  9. A multi-scale controlled tissue engineering scaffold prepared by 3D printing and NFES technology

    NASA Astrophysics Data System (ADS)

    Yan, Feifei; Liu, Yuanyuan; Chen, Haiping; Zhang, Fuhua; Zheng, Lulu; Hu, Qingxi

    2014-03-01

    The current focus in the field of life science is the use of tissue engineering scaffolds to repair human organs, which has shown great potential in clinical applications. Extracellular matrix morphology and the performance and internal structure of natural organs are required to meet certain requirements. Therefore, integrating multiple processes can effectively overcome the limitations of the individual processes and can take into account the needs of scaffolds for the material, structure, mechanical properties and many other aspects. This study combined the biological 3D printing technology and the near-field electro-spinning (NFES) process to prepare a multi-scale controlled tissue engineering scaffold. While using 3D printing technology to directly prepare the macro-scaffold, the compositing NFES process to build tissue micro-morphology ultimately formed a tissue engineering scaffold which has the specific extracellular matrix structure. This scaffold not only takes into account the material, structure, performance and many other requirements, but also focuses on resolving the controllability problems in macro- and micro-forming which further aim to induce cell directed differentiation, reproduction and, ultimately, the formation of target tissue organs. It has in-depth immeasurable significance to build ideal scaffolds and further promote the application of tissue engineering.

  10. Porous Allograft Bone Scaffolds: Doping with Strontium

    PubMed Central

    Zhao, Yantao; Guo, Dagang; Hou, Shuxun; Zhong, Hongbin; Yan, Jun; Zhang, Chunli; Zhou, Ying

    2013-01-01

    Strontium (Sr) can promote the process of bone formation. To improve bioactivity, porous allograft bone scaffolds (ABS) were doped with Sr and the mechanical strength and bioactivity of the scaffolds were evaluated. Sr-doped ABS were prepared using the ion exchange method. The density and distribution of Sr in bone scaffolds were investigated by inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectroscopy (EDS). Controlled release of strontium ions was measured and mechanical strength was evaluated by a compressive strength test. The bioactivity of Sr-doped ABS was investigated by a simulated body fluid (SBF) assay, cytotoxicity testing, and an in vivo implantation experiment. The Sr molar concentration [Sr/(Sr+Ca)] in ABS surpassed 5% and Sr was distributed nearly evenly. XPS analyses suggest that Sr combined with oxygen and carbonate radicals. Released Sr ions were detected in the immersion solution at higher concentration than calcium ions until day 30. The compressive strength of the Sr-doped ABS did not change significantly. The bioactivity of Sr-doped material, as measured by the in vitro SBF immersion method, was superior to that of the Sr-free freeze-dried bone and the Sr-doped material did not show cytotoxicity compared with Sr-free culture medium. The rate of bone mineral deposition for Sr-doped ABS was faster than that of the control at 4 weeks (3.28±0.23 µm/day vs. 2.60±0.20 µm/day; p<0.05). Sr can be evenly doped into porous ABS at relevant concentrations to create highly active bone substitutes. PMID:23922703

  11. Porous allograft bone scaffolds: doping with strontium.

    PubMed

    Zhao, Yantao; Guo, Dagang; Hou, Shuxun; Zhong, Hongbin; Yan, Jun; Zhang, Chunli; Zhou, Ying

    2013-01-01

    Strontium (Sr) can promote the process of bone formation. To improve bioactivity, porous allograft bone scaffolds (ABS) were doped with Sr and the mechanical strength and bioactivity of the scaffolds were evaluated. Sr-doped ABS were prepared using the ion exchange method. The density and distribution of Sr in bone scaffolds were investigated by inductively coupled plasma optical emission spectrometry (ICP-OES), X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectroscopy (EDS). Controlled release of strontium ions was measured and mechanical strength was evaluated by a compressive strength test. The bioactivity of Sr-doped ABS was investigated by a simulated body fluid (SBF) assay, cytotoxicity testing, and an in vivo implantation experiment. The Sr molar concentration [Sr/(Sr+Ca)] in ABS surpassed 5% and Sr was distributed nearly evenly. XPS analyses suggest that Sr combined with oxygen and carbonate radicals. Released Sr ions were detected in the immersion solution at higher concentration than calcium ions until day 30. The compressive strength of the Sr-doped ABS did not change significantly. The bioactivity of Sr-doped material, as measured by the in vitro SBF immersion method, was superior to that of the Sr-free freeze-dried bone and the Sr-doped material did not show cytotoxicity compared with Sr-free culture medium. The rate of bone mineral deposition for Sr-doped ABS was faster than that of the control at 4 weeks (3.28 ± 0.23 µm/day vs. 2.60 ± 0.20 µm/day; p<0.05). Sr can be evenly doped into porous ABS at relevant concentrations to create highly active bone substitutes. PMID:23922703

  12. Balancing mechanical strength with bioactivity in chitosan-calcium phosphate 3D microsphere scaffolds for bone tissue engineering: air- vs. freeze-drying processes.

    PubMed

    Nguyen, D T; McCanless, J D; Mecwan, M M; Noblett, A P; Haggard, W O; Smith, R A; Bumgardner, J D

    2013-01-01

    The objective of this study was to evaluate the potential benefit of 3D composite scaffolds composed of chitosan and calcium phosphate for bone tissue engineering. Additionally, incorporation of mechanically weak lyophilized microspheres within those air-dried (AD) was considered for enhanced bioactivity. AD microsphere, alone, and air- and freeze-dried microsphere (FDAD) 3D scaffolds were evaluated in vitro using a 28-day osteogenic culture model with the Saos-2 cell line. Mechanical testing, quantitative microscopy, and lysozyme-driven enzymatic degradation of the scaffolds were also studied. FDAD scaffold showed a higher concentration (p < 0.01) in cells per scaffold mass vs. AD constructs. Collagen was ∼31% greater (p < 0.01) on FDAD compared to AD scaffolds not evident in microscopy of microsphere surfaces. Alternatively, AD scaffolds demonstrated a superior threefold increase in compressive strength over FDAD (12 vs. 4 MPa) with minimal degradation. Inclusion of FD spheres within the FDAD scaffolds allowed increased cellular activity through improved seeding, proliferation, and extracellular matrix production (as collagen), although mechanical strength was sacrificed through introduction of the less stiff, porous FD spheres.

  13. Proliferation and enrichment of CD133(+) glioblastoma cancer stem cells on 3D chitosan-alginate scaffolds.

    PubMed

    Kievit, Forrest M; Florczyk, Stephen J; Leung, Matthew C; Wang, Kui; Wu, Jennifer D; Silber, John R; Ellenbogen, Richard G; Lee, Jerry S H; Zhang, Miqin

    2014-11-01

    Emerging evidence implicates cancer stem cells (CSCs) as primary determinants of the clinical behavior of human cancers, representing an ideal target for next-generation anti-cancer therapies. However CSCs are difficult to propagate in vitro, severely limiting the study of CSC biology and drug development. Here we report that growing cells from glioblastoma (GBM) cell lines on three dimensional (3D) porous chitosan-alginate (CA) scaffolds dramatically promotes the proliferation and enrichment of cells possessing the hallmarks of CSCs. CA scaffold-grown cells were found more tumorigenic in nude mouse xenografts than cells grown from monolayers. Growing in CA scaffolds rapidly promoted expression of genes involved in the epithelial-to-mesenchymal transition that has been implicated in the genesis of CSCs. Our results indicate that CA scaffolds have utility as a simple and inexpensive means to cultivate CSCs in vitro in support of studies to understand CSC biology and develop more effective anti-cancer therapies.

  14. Integration of 3D Printed and Micropatterned Polycaprolactone Scaffolds for Guidance of Oriented Collagenous Tissue Formation In Vivo.

    PubMed

    Pilipchuk, Sophia P; Monje, Alberto; Jiao, Yizu; Hao, Jie; Kruger, Laura; Flanagan, Colleen L; Hollister, Scott J; Giannobile, William V

    2016-03-01

    Scaffold design incorporating multiscale cues for clinically relevant, aligned tissue regeneration has potential to improve structural and functional integrity of multitissue interfaces. The objective of this preclinical study is to develop poly(ε-caprolactone) (PCL) scaffolds with mesoscale and microscale architectural cues specific to human ligament progenitor cells and assess their ability to form aligned bone-ligament-cementum complexes in vivo. PCL scaffolds are designed to integrate a 3D printed bone region with a micropatterned PCL thin film consisting of grooved pillars. The patterned film region is seeded with human ligament cells, fibroblasts transduced with bone morphogenetic protein-7 genes seeded within the bone region, and a tooth dentin segment positioned on the ligament region prior to subcutaneous implantation into a murine model. Results indicate increased tissue alignment in vivo using micropatterned PCL films, compared to random-porous PCL. At week 6, 30 μm groove depth significantly enhances oriented collagen fiber thickness, overall cell alignment, and nuclear elongation relative to 10 μm groove depth. This study demonstrates for the first time that scaffolds with combined hierarchical mesoscale and microscale features can align cells in vivo for oral tissue repair with potential for improving the regenerative response of other bone-ligament complexes.

  15. Micro-CT studies on 3-D bioactive glass-ceramic scaffolds for bone regeneration.

    PubMed

    Renghini, Chiara; Komlev, Vladimir; Fiori, Fabrizio; Verné, Enrica; Baino, Francesco; Vitale-Brovarone, Chiara

    2009-05-01

    The aim of this study was the preparation and characterization of bioactive glass-ceramic scaffolds for bone tissue engineering. For this purpose, a glass belonging to the system SiO2-P2O5-CaO-MgO-Na2O-K2O (CEL2) was used. The sponge-replication method was adopted to prepare the scaffolds; specifically, a polymeric skeleton was impregnated with a slurry containing CEL2 powder, polyvinyl alcohol (PVA) as a binding agent and distilled water. The impregnated sponge was then thermally treated to remove the polymeric phase and to sinter the inorganic one. The obtained scaffolds possessed an open and interconnected porosity, analogous to cancellous bone texture, and with a mechanical strength above 2 MPa. Moreover, the scaffolds underwent partial bioresorption due to ion-leaching phenomena. This feature was investigated by X-ray computed microcomputed tomography (micro-CT). Micro-CT is a three-dimensional (3-D) radiographic imaging technique, able to achieve a spatial resolution close to 1 microm(3). The use of synchrotron radiation allows the selected photon energy to be tuned to optimize the contrast among the different phases in the investigated samples. The 3-D scaffolds were soaked in a simulated body fluid (SBF) to study the formation of hydroxyapatite microcrystals on the scaffold struts and on the internal pore walls. The 3-D scaffolds were also soaked in a buffer solution (Tris-HCl) for different times to assess the scaffold bioresorption according to the ISO standard. A gradual resorption of the pores walls was observed during the soakings both in SBF and in Tris-HCl.

  16. Fabrication of computationally designed scaffolds by low temperature 3D printing.

    PubMed

    Castilho, Miguel; Dias, Marta; Gbureck, Uwe; Groll, Jürgen; Fernandes, Paulo; Pires, Inês; Gouveia, Barbara; Rodrigues, Jorge; Vorndran, Elke

    2013-09-01

    The development of artificial bone substitutes that mimic the properties of bone and simultaneously promote the desired tissue regeneration is a current issue in bone tissue engineering research. An approach to create scaffolds with such characteristics is based on the combination of novel design and additive manufacturing processes. The objective of this work is to characterize the microstructural and the mechanical properties of scaffolds developed by coupling both topology optimization and a low temperature 3D printing process. The scaffold design was obtained using a topology optimization approach to maximize the permeability with constraints on the mechanical properties. This procedure was studied to be suitable for the fabrication of a cage prototype for tibial tuberosity advancement application, which is one of the most recent and promising techniques to treat cruciate ligament rupture in dogs. The microstructural and mechanical properties of the scaffolds manufactured by reacting α/β-tricalcium phosphate with diluted phosphoric acid were then assessed experimentally and the scaffolds strength reliability was determined. The results demonstrate that the low temperature 3D printing process is a reliable option to create synthetic scaffolds with tailored properties, and when coupled with topology optimization design it can be a powerful tool for the fabrication of patient-specific bone implants. PMID:23887064

  17. Engineering EMT using 3D micro-scaffold to promote hepatic functions for drug hepatotoxicity evaluation.

    PubMed

    Wang, Jingyu; Chen, Fengling; Liu, Longwei; Qi, Chunxiao; Wang, Bingjie; Yan, Xiaojun; Huang, Chenyu; Hou, Wei; Zhang, Michael Q; Chen, Yang; Du, Yanan

    2016-06-01

    Accompanied by decreased hepatic functions, epithelial-mesenchymal transition (EMT) was observed in two dimensional (2D) cultured hepatocytes with elongated morphology, loss of polarity and weakened cell-cell interaction, while upgrading to 3D culture has been considered as significant improvement of its 2D counterpart for hepatocyte maintenance. Here we hypothesize that 3D culture enhances hepatic functions through regulating the EMT status. Biomaterial-engineered EMT was achieved by culturing HepaRG as 3D spheroids (SP-3D) or 3D stretched cells (ST-3D) in non-adherent and adherent micro-scaffold respectively. In SP-3D, constrained EMT of HepaRG, a hepatic stem cell line, as represented by increased epithelial markers and decreased mesenchymal markers, was echoed by improved hepatic functions. To investigate the relationship between EMT status and hepatic functions, time-series RNA-Seq and gene network analysis were used for comparing different cell culture models, which identified histone deacetylases (HDACs) as key mediating factors. Protein analysis confirmed that high HDAC activity was correlated with high expression of Cadherin-1 (CDH1) and hepatic function genes, which were decreased upon HDAC inhibitor treatment in SP-3D, suggesting HDACs may play positive role in regulating EMT and hepatic functions. To illustrate the application of 3D micro-scaffold culture in drug safety evaluation, hepatotoxicity and metabolism assays of two hepatotoxins (i.e. N-acetyl-p-aminophenol and Doxorubicin) were performed and SP-3D showed more biomimetic toxicity response, indicating regulation of EMT as a vital consideration in designing 3D hepatocyte culture configuration.

  18. Preparation of 3D fibrin scaffolds for stem cell culture applications.

    PubMed

    Kolehmainen, Kathleen; Willerth, Stephanie M

    2012-01-01

    Stem cells are found in naturally occurring 3D microenvironments in vivo, which are often referred to as the stem cell niche. Culturing stem cells inside of 3D biomaterial scaffolds provides a way to accurately mimic these microenvironments, providing an advantage over traditional 2D culture methods using polystyrene as well as a method for engineering replacement tissues. While 2D tissue culture polystrene has been used for the majority of cell culture experiments, 3D biomaterial scaffolds can more closely replicate the microenvironments found in vivo by enabling more accurate establishment of cell polarity in the environment and possessing biochemical and mechanical properties similar to soft tissue. A variety of naturally derived and synthetic biomaterial scaffolds have been investigated as 3D environments for supporting stem cell growth. While synthetic scaffolds can be synthesized to have a greater range of mechanical and chemical properties and often have greater reproducibility, natural biomaterials are often composed of proteins and polysaccharides found in the extracelluar matrix and as a result contain binding sites for cell adhesion and readily support cell culture. Fibrin scaffolds, produced by polymerizing the protein fibrinogen obtained from plasma, have been widely investigated for a variety of tissue engineering applications both in vitro and in vivo. Such scaffolds can be modified using a variety of methods to incorporate controlled release systems for delivering therapeutic factors. Previous work has shown that such scaffolds can be used to successfully culture embryonic stem cells and this scaffold-based culture system can be used to screen the effects of various growth factors on the differentiation of the stem cells seeded inside. This protocol details the process of polymerizing fibrin scaffolds from fibrinogen solutions using the enzymatic activity of thrombin. The process takes 2 days to complete, including an overnight dialysis step for the

  19. Preparation of 3D Fibrin Scaffolds for Stem Cell Culture Applications

    PubMed Central

    Kolehmainen, Kathleen; Willerth, Stephanie M.

    2012-01-01

    Stem cells are found in naturally occurring 3D microenvironments in vivo, which are often referred to as the stem cell niche 1. Culturing stem cells inside of 3D biomaterial scaffolds provides a way to accurately mimic these microenvironments, providing an advantage over traditional 2D culture methods using polystyrene as well as a method for engineering replacement tissues 2. While 2D tissue culture polystrene has been used for the majority of cell culture experiments, 3D biomaterial scaffolds can more closely replicate the microenvironments found in vivo by enabling more accurate establishment of cell polarity in the environment and possessing biochemical and mechanical properties similar to soft tissue.3 A variety of naturally derived and synthetic biomaterial scaffolds have been investigated as 3D environments for supporting stem cell growth. While synthetic scaffolds can be synthesized to have a greater range of mechanical and chemical properties and often have greater reproducibility, natural biomaterials are often composed of proteins and polysaccharides found in the extracelluar matrix and as a result contain binding sites for cell adhesion and readily support cell culture. Fibrin scaffolds, produced by polymerizing the protein fibrinogen obtained from plasma, have been widely investigated for a variety of tissue engineering applications both in vitro and in vivo4. Such scaffolds can be modified using a variety of methods to incorporate controlled release systems for delivering therapeutic factors 5. Previous work has shown that such scaffolds can be used to successfully culture embryonic stem cells and this scaffold-based culture system can be used to screen the effects of various growth factors on the differentiation of the stem cells seeded inside 6,7. This protocol details the process of polymerizing fibrin scaffolds from fibrinogen solutions using the enzymatic activity of thrombin. The process takes 2 days to complete, including an overnight dialysis

  20. 3D-Printed Scaffolds and Biomaterials: Review of Alveolar Bone Augmentation and Periodontal Regeneration Applications

    PubMed Central

    Asa'ad, Farah; Giannì, Aldo Bruno; Giannobile, William V.; Rasperini, Giulio

    2016-01-01

    To ensure a successful dental implant therapy, the presence of adequate vertical and horizontal alveolar bone is fundamental. However, an insufficient amount of alveolar ridge in both dimensions is often encountered in dental practice due to the consequences of oral diseases and tooth loss. Although postextraction socket preservation has been adopted to lessen the need for such invasive approaches, it utilizes bone grafting materials, which have limitations that could negatively affect the quality of bone formation. To overcome the drawbacks of routinely employed grafting materials, bone graft substitutes such as 3D scaffolds have been recently investigated in the dental field. In this review, we highlight different biomaterials suitable for 3D scaffold fabrication, with a focus on “3D-printed” ones as bone graft substitutes that might be convenient for various applications related to implant therapy. We also briefly discuss their possible adoption for periodontal regeneration. PMID:27366149

  1. 3D-Printed Scaffolds and Biomaterials: Review of Alveolar Bone Augmentation and Periodontal Regeneration Applications.

    PubMed

    Asa'ad, Farah; Pagni, Giorgio; Pilipchuk, Sophia P; Giannì, Aldo Bruno; Giannobile, William V; Rasperini, Giulio

    2016-01-01

    To ensure a successful dental implant therapy, the presence of adequate vertical and horizontal alveolar bone is fundamental. However, an insufficient amount of alveolar ridge in both dimensions is often encountered in dental practice due to the consequences of oral diseases and tooth loss. Although postextraction socket preservation has been adopted to lessen the need for such invasive approaches, it utilizes bone grafting materials, which have limitations that could negatively affect the quality of bone formation. To overcome the drawbacks of routinely employed grafting materials, bone graft substitutes such as 3D scaffolds have been recently investigated in the dental field. In this review, we highlight different biomaterials suitable for 3D scaffold fabrication, with a focus on "3D-printed" ones as bone graft substitutes that might be convenient for various applications related to implant therapy. We also briefly discuss their possible adoption for periodontal regeneration. PMID:27366149

  2. 3D Scaffolds with Different Stiffness but the Same Microstructure for Bone Tissue Engineering.

    PubMed

    Chen, Guobao; Dong, Chanjuan; Yang, Li; Lv, Yonggang

    2015-07-29

    A growing body of evidence has shown that extracellular matrix (ECM) stiffness can modulate stem cell adhesion, proliferation, migration, differentiation, and signaling. Stem cells can feel and respond sensitively to the mechanical microenvironment of the ECM. However, most studies have focused on classical two-dimensional (2D) or quasi-three-dimensional environments, which cannot represent the real situation in vivo. Furthermore, most of the current methods used to generate different mechanical properties invariably change the fundamental structural properties of the scaffolds (such as morphology, porosity, pore size, and pore interconnectivity). In this study, we have developed novel three-dimensional (3D) scaffolds with different degrees of stiffness but the same 3D microstructure that was maintained by using decellularized cancellous bone. Mixtures of collagen and hydroxyapatite [HA: Ca10(PO4)6(OH)2] with different proportions were coated on decellularized cancellous bone to vary the stiffness (local stiffness, 13.00 ± 5.55 kPa, 13.87 ± 1.51 kPa, and 37.7 ± 19.6 kPa; bulk stiffness, 6.74 ± 1.16 kPa, 8.82 ± 2.12 kPa, and 23.61 ± 8.06 kPa). Microcomputed tomography (μ-CT) assay proved that there was no statistically significant difference in the architecture of the scaffolds before or after coating. Cell viability, osteogenic differentiation, cell recruitment, and angiogenesis were determined to characterize the scaffolds and evaluate their biological responses in vitro and in vivo. The in vitro results indicate that the scaffolds developed in this study could sustain adhesion and growth of rat mesenchymal stem cells (MSCs) and promote their osteogenic differentiation. The in vivo results further demonstrated that these scaffolds could help to recruit MSCs from subcutaneous tissue, induce them to differentiate into osteoblasts, and provide the 3D environment for angiogenesis. These findings showed that the method we developed can build scaffolds with

  3. 3D polylactide-based scaffolds for studying human hepatocarcinoma processes in vitro

    NASA Astrophysics Data System (ADS)

    Scaffaro, Roberto; Lo Re, Giada; Rigogliuso, Salvatrice; Ghersi, Giulio

    2012-08-01

    We evaluated the combination of leaching techniques and melt blending of polymers and particles for the preparation of highly interconnected three-dimensional polymeric porous scaffolds for in vitro studies of human hepatocarcinoma processes. More specifically, sodium chloride and poly(ethylene glycol) (PEG) were used as water-soluble porogens to form porous and solvent-free poly(L,D-lactide) (PLA)-based scaffolds. Several characterization techniques, including porosimetry, image analysis and thermogravimetry, were combined to improve the reliability of measurements and mapping of the size, distribution and microarchitecture of pores. We also investigated the effect of processing, in PLA-based blends, on the simultaneous bulk/surface modifications and pore architectures in the scaffolds, and assessed the effects on human hepatocarcinoma viability and cell adhesion. The influence of PEG molecular weight on the scaffold morphology and cell viability and adhesion were also investigated. Morphological studies indicated that it was possible to obtain scaffolds with well-interconnected pores of assorted sizes. The analysis confirmed that SK-Hep1 cells adhered well to the polymeric support and emitted surface protrusions necessary to grow and differentiate three-dimensional systems. PEGs with higher molecular weight showed the best results in terms of cell adhesion and viability.

  4. 3D Printing of Composite Calcium Phosphate and Collagen Scaffolds for Bone Regeneration

    PubMed Central

    Inzana, Jason A.; Olvera, Diana; Fuller, Seth M.; Kelly, James P.; Graeve, Olivia A.; Schwarz, Edward M.; Kates, Stephen L.; Awad, Hani A.

    2014-01-01

    Low temperature 3D printing of calcium phosphate scaffolds holds great promise for fabricating synthetic bone graft substitutes with enhanced performance over traditional techniques. Many design parameters, such as the binder solution properties, have yet to be optimized to ensure maximal biocompatibility and osteoconductivity with sufficient mechanical properties. This study tailored the phosphoric acid-based binder solution concentration to 8.75 wt% to maximize cytocompatibility and mechanical strength, with a supplementation of Tween 80 to improve printing. To further enhance the formulation, collagen was dissolved into the binder solution to fabricate collagen-calcium phosphate composites. Reducing the viscosity and surface tension through a physiologic heat treatment and Tween 80, respectively, enabled reliable thermal inkjet printing of the collagen solutions. Supplementing the binder solution with 1–2 wt% collagen significantly improved maximum flexural strength and cell viability. To assess the bone healing performance, we implanted 3D printed scaffolds into a critically sized murine femoral defect for 9 weeks. The implants were confirmed to be osteoconductive, with new bone growth incorporating the degrading scaffold materials. In conclusion, this study demonstrates optimization of material parameters for 3D printed calcium phosphate scaffolds and enhancement of material properties by volumetric collagen incorporation via inkjet printing. PMID:24529628

  5. 3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration.

    PubMed

    Inzana, Jason A; Olvera, Diana; Fuller, Seth M; Kelly, James P; Graeve, Olivia A; Schwarz, Edward M; Kates, Stephen L; Awad, Hani A

    2014-04-01

    Low temperature 3D printing of calcium phosphate scaffolds holds great promise for fabricating synthetic bone graft substitutes with enhanced performance over traditional techniques. Many design parameters, such as the binder solution properties, have yet to be optimized to ensure maximal biocompatibility and osteoconductivity with sufficient mechanical properties. This study tailored the phosphoric acid-based binder solution concentration to 8.75 wt% to maximize cytocompatibility and mechanical strength, with a supplementation of Tween 80 to improve printing. To further enhance the formulation, collagen was dissolved into the binder solution to fabricate collagen-calcium phosphate composites. Reducing the viscosity and surface tension through a physiologic heat treatment and Tween 80, respectively, enabled reliable thermal inkjet printing of the collagen solutions. Supplementing the binder solution with 1-2 wt% collagen significantly improved maximum flexural strength and cell viability. To assess the bone healing performance, we implanted 3D printed scaffolds into a critically sized murine femoral defect for 9 weeks. The implants were confirmed to be osteoconductive, with new bone growth incorporating the degrading scaffold materials. In conclusion, this study demonstrates optimization of material parameters for 3D printed calcium phosphate scaffolds and enhancement of material properties by volumetric collagen incorporation via inkjet printing.

  6. 3D finite element analysis of porous Ti-based alloy prostheses.

    PubMed

    Mircheski, Ile; Gradišar, Marko

    2016-11-01

    In this paper, novel designs of porous acetabular cups are created and tested with 3D finite element analysis (FEA). The aim is to develop a porous acetabular cup with low effective radial stiffness of the structure, which will be near to the architectural and mechanical behavior of the natural bone. For the realization of this research, a 3D-scanner technology was used for obtaining a 3D-CAD model of the pelvis bone, a 3D-CAD software for creating a porous acetabular cup, and a 3D-FEA software for virtual testing of a novel design of the porous acetabular cup. The results obtained from this research reveal that a porous acetabular cup from Ti-based alloys with 60 ± 5% porosity has the mechanical behavior and effective radial stiffness (Young's modulus in radial direction) that meet and exceed the required properties of the natural bone. The virtual testing with 3D-FEA of a novel design with porous structure during the very early stage of the design and the development of orthopedic implants, enables obtaining a new or improved biomedical implant for a relatively short time and reduced price.

  7. 3-D intestinal scaffolds for evaluating the therapeutic potential of probiotics.

    PubMed

    Costello, Cait M; Sorna, Rachel M; Goh, Yih-Lin; Cengic, Ivana; Jain, Nina K; March, John C

    2014-07-01

    Biomimetic in vitro intestinal models are becoming useful tools for studying host-microbial interactions. In the past, these models have typically been limited to simple cultures on 2-D scaffolds or Transwell inserts, but it is widely understood that epithelial cells cultured in 3-D environments exhibit different phenotypes that are more reflective of native tissue, and that different microbial species will preferentially adhere to select locations along the intestinal villi. We used a synthetic 3-D tissue scaffold with villous features that could support the coculture of epithelial cell types with select bacterial populations. Our end goal was to establish microbial niches along the crypt-villus axis in order to mimic the natural microenvironment of the small intestine, which could potentially provide new insights into microbe-induced intestinal disorders, as well as enabling targeted probiotic therapies. We recreated the surface topography of the small intestine by fabricating a biodegradable and biocompatible villous scaffold using poly lactic-glycolic acid to enable the culture of Caco-2 with differentiation along the crypt-villus axis in a similar manner to native intestines. This was then used as a platform to mimic the adhesion and invasion profiles of both Salmonella and Pseudomonas, and assess the therapeutic potential of Lactobacillus and commensal Escherichia coli in a 3-D setting. We found that, in a 3-D environment, Lactobacillus is more successful at displacing pathogens, whereas Nissle is more effective at inhibiting pathogen adhesion. PMID:24798584

  8. Elastic properties of model 3-D porous ceramics and foams

    NASA Astrophysics Data System (ADS)

    Roberts, Anthony; Garboczi, Edward

    2000-03-01

    The novel properties of many new porous materials are related to their interesting internal microstructure. Apart from simple cases, there exist no theoretical means of predicting the bulk properties of these materials. This limits our ability to guide microstructure optimization for a particular purpose. We use a large scale finite element method to demonstrate the complex relationship between microstructure and the effective properties of realistic three-dimensional model porous ceramics and foams. We find that pore-shape and interconnectivity strongly influence the properties of sintered ceramics. For porous foams we have studied the role of coordination number, random disorder, and strut shape on the Young's modulus and Poisson's ratio. We find that that Voronoi tesselations, commonly used to model solid foams, show unphysical behavior, in particular they are incompressible (rubber-like) at low densities. Deletion of just 10% of the bonds in the model reduces the bulk modulus by 75%, more in line with experimental evidence. The FEM results are generally in good agreement with experimental data for ceramics and foams, and can be used as both a predictive and interpretative tool by experimentalists.

  9. The Potential of Encapsulating “Raw Materials” in 3D Osteochondral Gradient Scaffolds

    PubMed Central

    Mohan, Neethu; Gupta, Vineet; Sridharan, BanuPriya; Sutherland, Amanda; Detamore, Michael S.

    2015-01-01

    Scaffolds with continuous gradients in material composition and bioactive signals enable a smooth transition of properties at the interface. Components like chondroitin sulfate (CS) and bioactive glass (BG) in 3D scaffolds may serve as “raw materials” for synthesis of new extracellular matrix (ECM), and may have the potential to completely or partially replace expensive growth factors. We hypothesized that scaffolds with gradients of ECM components would enable superior performance of engineered constructs. Raw material encapsulation altered the appearance, structure, porosity, and degradation of the scaffolds. They allowed the scaffolds to better retain their 3D structure during culture and provided a buffering effect to the cells in culture. Following seeding of rat mesenchymal stem cells, there were several instances where glycosaminoglycan (GAG), collagen, or calcium contents were higher with the scaffolds containing raw materials (CS or BG) than with those containing transforming growth factor (TGF)-β3 or bone morphogenetic protein (BMP)-2. It was also noteworthy that a combination of both CS and TGF-β3 increased the secretion of collagen type II. Moreover, cells seeded in scaffolds containing opposing gradients of CS/TGF-β3 and BG/BMP-2 produced clear regional variations in the secretion of tissue-specific ECM. The study demonstrated raw materials have the potential to create a favorable microenvironment for cells; they can significantly enhance the synthesis of certain extracellular matrix (ECM) components when compared to expensive growth factors; either alone or in combination with growth factors they can enhance the secretion of tissue specific matrix proteins. Raw materials are promising candidates that can be used to either replace or be used in combination with growth factors. Success with raw materials in lieu of growth factors could have profound implications in terms of lower cost and faster regulatory approval for more rapid translation of

  10. SrO- and MgO-doped microwave sintered 3D printed tricalcium phosphate scaffolds: mechanical properties and in vivo osteogenesis in a rabbit model.

    PubMed

    Tarafder, Solaiman; Dernell, William S; Bandyopadhyay, Amit; Bose, Susmita

    2015-04-01

    The presence of interconnected macro pores allows guided tissue regeneration in tissue engineering scaffolds. However, highly porous scaffolds suffer from having poor mechanical strength. Previously, we showed that microwave sintering could successfully be used to improve mechanical strength of macro porous tricalcium phosphate (TCP) scaffolds. This study reports the presence of SrO and MgO as dopants in TCP scaffolds improves mechanical and in vivo biological performance. We have used direct three dimensional printing (3DP) technology for scaffold fabrication. These 3DP scaffolds possessed multiscale porosity, that is, 3D interconnected designed macro pores along with intrinsic micro pores. A significant increase in mechanical strength, between 37 and 41%, was achieved due to SrO and MgO doping in TCP as compared with pure TCP. Maximum compressive strengths of 9.38 ± 1.86 MPa and 12.01 ± 1.56 MPa were achieved by conventional and microwave sintering, respectively, for SrO-MgO-doped 3DP scaffolds with 500 μm designed pores. Histomorphological and histomorphometric analysis revealed a significantly higher osteoid, bone and haversian canal formation induced by the presence of SrO and MgO dopants in 3DP TCP as compared with pure TCP scaffolds when tested in rabbit femoral condyle defect model. Increased osteon and thus enhanced network of blood vessel formation, and osteocalcin expression were observed in the doped TCP scaffolds. Our results show that these 3DP SrO-MgO-doped TCP scaffolds have the potential for early wound healing through accelerated osteogenesis and vasculogenesis. PMID:25045131

  11. SrO- and MgO-doped microwave sintered 3D printed tricalcium phosphate scaffolds: mechanical properties and in vivo osteogenesis in a rabbit model.

    PubMed

    Tarafder, Solaiman; Dernell, William S; Bandyopadhyay, Amit; Bose, Susmita

    2015-04-01

    The presence of interconnected macro pores allows guided tissue regeneration in tissue engineering scaffolds. However, highly porous scaffolds suffer from having poor mechanical strength. Previously, we showed that microwave sintering could successfully be used to improve mechanical strength of macro porous tricalcium phosphate (TCP) scaffolds. This study reports the presence of SrO and MgO as dopants in TCP scaffolds improves mechanical and in vivo biological performance. We have used direct three dimensional printing (3DP) technology for scaffold fabrication. These 3DP scaffolds possessed multiscale porosity, that is, 3D interconnected designed macro pores along with intrinsic micro pores. A significant increase in mechanical strength, between 37 and 41%, was achieved due to SrO and MgO doping in TCP as compared with pure TCP. Maximum compressive strengths of 9.38 ± 1.86 MPa and 12.01 ± 1.56 MPa were achieved by conventional and microwave sintering, respectively, for SrO-MgO-doped 3DP scaffolds with 500 μm designed pores. Histomorphological and histomorphometric analysis revealed a significantly higher osteoid, bone and haversian canal formation induced by the presence of SrO and MgO dopants in 3DP TCP as compared with pure TCP scaffolds when tested in rabbit femoral condyle defect model. Increased osteon and thus enhanced network of blood vessel formation, and osteocalcin expression were observed in the doped TCP scaffolds. Our results show that these 3DP SrO-MgO-doped TCP scaffolds have the potential for early wound healing through accelerated osteogenesis and vasculogenesis.

  12. 3D Hierarchical Porous Mo2 C for Efficient Hydrogen Evolution.

    PubMed

    Ang, Huixiang; Wang, Huanwen; Li, Bing; Zong, Yun; Wang, Xuefeng; Yan, Qingyu

    2016-06-01

    Porous electrocatalyst for hydrogen production. 3D hierarchical porous molybdenum carbide provides a low operating potential (97 mV at 10 mA cm(-2) ). These beneficial textures of large specific surface area (302 m(2) g(-1) ) and hierarchical porous architecture containing dominant pore size distribution peak at 11 Å in width can provide large surface active sites and facilitate proton mass transport. PMID:27076208

  13. Porous Biodegradable Metals for Hard Tissue Scaffolds: A Review

    PubMed Central

    Yusop, A. H.; Bakir, A. A.; Shaharom, N. A.; Abdul Kadir, M. R.; Hermawan, H.

    2012-01-01

    Scaffolds have been utilized in tissue regeneration to facilitate the formation and maturation of new tissues or organs where a balance between temporary mechanical support and mass transport (degradation and cell growth) is ideally achieved. Polymers have been widely chosen as tissue scaffolding material having a good combination of biodegradability, biocompatibility, and porous structure. Metals that can degrade in physiological environment, namely, biodegradable metals, are proposed as potential materials for hard tissue scaffolding where biodegradable polymers are often considered as having poor mechanical properties. Biodegradable metal scaffolds have showed interesting mechanical property that was close to that of human bone with tailored degradation behaviour. The current promising fabrication technique for making scaffolds, such as computation-aided solid free-form method, can be easily applied to metals. With further optimization in topologically ordered porosity design exploiting material property and fabrication technique, porous biodegradable metals could be the potential materials for making hard tissue scaffolds. PMID:22919393

  14. Fabrication of scalable and structured tissue engineering scaffolds using water dissolvable sacrificial 3D printed moulds.

    PubMed

    Mohanty, Soumyaranjan; Larsen, Layla Bashir; Trifol, Jon; Szabo, Peter; Burri, Harsha Vardhan Reddy; Canali, Chiara; Dufva, Marin; Emnéus, Jenny; Wolff, Anders

    2015-10-01

    One of the major challenges in producing large scale engineered tissue is the lack of ability to create large highly perfused scaffolds in which cells can grow at a high cell density and viability. Here, we explore 3D printed polyvinyl alcohol (PVA) as a sacrificial mould in a polymer casting process. The PVA mould network defines the channels and is dissolved after curing the polymer casted around it. The printing parameters determined the PVA filament density in the sacrificial structure and this density resulted in different stiffness of the corresponding elastomer replica. It was possible to achieve 80% porosity corresponding to about 150 cm(2)/cm(3) surface to volume ratio. The process is easily scalable as demonstrated by fabricating a 75 cm(3) scaffold with about 16,000 interconnected channels (about 1m(2) surface area) and with a channel to channel distance of only 78 μm. To our knowledge this is the largest scaffold ever to be produced with such small feature sizes and with so many structured channels. The fabricated scaffolds were applied for in-vitro culturing of hepatocytes over a 12-day culture period. Smaller scaffolds (6×4 mm) were tested for cell culturing and could support homogeneous cell growth throughout the scaffold. Presumably, the diffusion of oxygen and nutrient throughout the channel network is rapid enough to support cell growth. In conclusion, the described process is scalable, compatible with cell culture, rapid, and inexpensive. PMID:26117791

  15. 3D Chemical Similarity Networks for Structure-Based Target Prediction and Scaffold Hopping.

    PubMed

    Lo, Yu-Chen; Senese, Silvia; Damoiseaux, Robert; Torres, Jorge Z

    2016-08-19

    Target identification remains a major challenge for modern drug discovery programs aimed at understanding the molecular mechanisms of drugs. Computational target prediction approaches like 2D chemical similarity searches have been widely used but are limited to structures sharing high chemical similarity. Here, we present a new computational approach called chemical similarity network analysis pull-down 3D (CSNAP3D) that combines 3D chemical similarity metrics and network algorithms for structure-based drug target profiling, ligand deorphanization, and automated identification of scaffold hopping compounds. In conjunction with 2D chemical similarity fingerprints, CSNAP3D achieved a >95% success rate in correctly predicting the drug targets of 206 known drugs. Significant improvement in target prediction was observed for HIV reverse transcriptase (HIVRT) compounds, which consist of diverse scaffold hopping compounds targeting the nucleotidyltransferase binding site. CSNAP3D was further applied to a set of antimitotic compounds identified in a cell-based chemical screen and identified novel small molecules that share a pharmacophore with Taxol and display a Taxol-like mechanism of action, which were validated experimentally using in vitro microtubule polymerization assays and cell-based assays.

  16. Impact of 3-D printed PLA- and chitosan-based scaffolds on human monocyte/macrophage responses: unraveling the effect of 3-D structures on inflammation.

    PubMed

    Almeida, Catarina R; Serra, Tiziano; Oliveira, Marta I; Planell, Josep A; Barbosa, Mário A; Navarro, Melba

    2014-02-01

    Recent studies have pointed towards a decisive role of inflammation in triggering tissue repair and regeneration, while at the same time it is accepted that an exacerbated inflammatory response may lead to rejection of an implant. Within this context, understanding and having the capacity to regulate the inflammatory response elicited by 3-D scaffolds aimed for tissue regeneration is crucial. This work reports on the analysis of the cytokine profile of human monocytes/macrophages in contact with biodegradable 3-D scaffolds with different surface properties, architecture and controlled pore geometry, fabricated by 3-D printing technology. Fabrication processes were optimized to create four different 3-D platforms based on polylactic acid (PLA), PLA/calcium phosphate glass or chitosan. Cytokine secretion and cell morphology of human peripheral blood monocytes allowed to differentiate on the different matrices were analyzed. While all scaffolds supported monocyte/macrophage adhesion and stimulated cytokine production, striking differences between PLA-based and chitosan scaffolds were found, with chitosan eliciting increased secretion of tumor necrosis factor (TNF)-α, while PLA-based scaffolds induced higher production of interleukin (IL)-6, IL-12/23 and IL-10. Even though the material itself induced the biggest differences, the scaffold geometry also impacted on TNF-α and IL-12/23 production, with chitosan scaffolds having larger pores and wider angles leading to a higher secretion of these pro-inflammatory cytokines. These findings strengthen the appropriateness of these 3-D platforms to study modulation of macrophage responses by specific parameters (chemistry, topography, scaffold architecture). PMID:24211731

  17. Non-bioengineered silk fibroin protein 3D scaffolds for potential biotechnological and tissue engineering applications.

    PubMed

    Mandal, Biman B; Kundu, Subhas C

    2008-09-01

    This paper describes a new source for fabricating high-strength, non-bioengineered silk gland fibroin 3D scaffolds from Indian tropical tasar silkworm, Antheraea mylitta using SDS for dissolution. The scaffolds were fabricated by freeze drying at different prefreezing temperatures for pore size and porosity optimization. Superior mechanical properties with compressive strength in the range of 972 kPa were observed. The matrices were degraded by proteases within 28 d of incubation. Biocompatibility was assessed by feline fibroblast culture in vitro and confocal microscopy further confirmed adherence, spreading, and proliferation of primary dermal fibroblasts. Results indicate nonmulberry 3D silk gland fibroin protein as an inexpensive, high-strength, slow biodegradable, biocompatible, and alternative natural biomaterial. [Figure: see text]. PMID:18702171

  18. Chitosan-g-lactide copolymers for fabrication of 3D scaffolds for tissue engineering

    NASA Astrophysics Data System (ADS)

    Demina, T. S.; Zaytseva-Zotova, D. S.; Timashev, P. S.; Bagratashvili, V. N.; Bardakova, K. N.; Sevrin, Ch; Svidchenko, E. A.; Surin, N. M.; Markvicheva, E. A.; Grandfils, Ch; Akopova, T. A.

    2015-07-01

    Chitosan-g-oligo (L, D-lactide) copolymers were synthesized and assessed to fabricate a number of 3D scaffolds using a variety of technologies such as oil/water emulsion evaporation technique, freeze-drying and two-photon photopolymerization. Solid-state copolymerization method allowed us to graft up to 160 wt-% of oligolactide onto chitosan backbone via chitosan amino group acetylation with substitution degree reaching up to 0.41. Grafting of hydrophobic oligolactide side chains with polymerization degree up to 10 results in chitosan amphiphilic properties. The synthesized chitosan-g-lactide copolymers were used to design 3D scaffolds for tissue engineering such as spherical microparticles and macroporous hydrogels.

  19. Modulating mechanical behaviour of 3D-printed cartilage-mimetic PCL scaffolds: influence of molecular weight and pore geometry.

    PubMed

    Olubamiji, Adeola D; Izadifar, Zohreh; Si, Jennifer L; Cooper, David M L; Eames, B Frank; Chen, Daniel X B

    2016-06-01

    Three-dimensional (3D)-printed poly(ε)-caprolactone (PCL)-based scaffolds are increasingly being explored for cartilage tissue engineering (CTE) applications. However, ensuring that the mechanical properties of these PCL-based constructs are comparable to that of articular cartilage that they are meant to regenerate is an area that has been under-explored. This paper presents the effects of PCL's molecular weight (MW) and scaffold's pore geometric configurations; strand size (SZ), strand spacing (SS), and strand orientation (SO), on mechanical properties of 3D-printed PCL scaffolds. The results illustrate that MW has significant effect on compressive moduli and yield strength of 3D-printed PCL scaffolds. Specifically, PCL with MW of 45 K was a more feasible choice for fabrication of visco-elastic, flexible and load-bearing PCL scaffolds. Furthermore, pore geometric configurations; SZ, SS, and SO, all significantly affect on tensile moduli of scaffolds. However, only SZ and SS have statistically significant effects on compressive moduli and porosity of these scaffolds. That said, inverse linear relationship was observed between porosity and mechanical properties of 3D-printed PCL scaffolds in Pearson's correlation test. Altogether, this study illustrates that modulating MW of PCL and pore geometrical configurations of the scaffolds enabled design and fabrication of PCL scaffolds with mechanical and biomimetic properties that better mimic mechanical behaviour of human articular cartilage. Thus, the modulated PCL scaffold proposed in this study is a framework that offers great potentials for CTE applications. PMID:27328736

  20. Vorticity and upscaled dispersion in 3D heterogeneous porous media

    NASA Astrophysics Data System (ADS)

    Di Dato, Mariaines; Chiogna, Gabriele; de Barros, Felipe; Bellin, Alberto; Fiori, Aldo

    2015-04-01

    Modeling flow in porous media is relevant for many environmental, energy and industrial applications. From an environmental perspective, the relevance of porous media flow becomes evident in subsurface hydrology. In general, flow in natural porous media is creeping, yet the large variability in the hydraulic conductivity values encountered in natural aquifers leads to highly heterogeneous flow fields. This natural variability in the conductivity field will affect both dilution rates of chemical species and reactive mixing. A physical consequence of this heterogeneity is also the presence of a various localized kinematical features such as straining, shearing and vorticity in aquifers, which will influence the shape of solute clouds and its fate and transport. This work aims in fundamentally characterizing the vorticity field in spatially heterogeneous flow fields as a function of their statistical properties in order to analyze the impact on transport processes. In our study, three-dimensional porous formations are constructed with an ensemble of N independent, non-overlapping spheroidal inclusions submerged into an homogeneous matrix, of conductivity K0. The inclusions are randomly located in a domain of volume W and are fully characterized by the geometry of spheroid (oblate or prolate), their conductivity K (random and drawn from a given probability density function fκ), the centroid location ¯x, the axes ratio e, the orientation of the rotational axis (α1,α2) and the volume w. Under the assumption of diluted medium, the flow problem is solved analitically by means of only two parameters: the conductivity contrast κ = K/K0 and the volume fraction n = Nw/W . Through the variation of these parameters of the problem, it is possible to approximate the structure of natural heterogeneous porous media. Using a random distribution of the orientation of the inclusions, we create media defined by the same global anisotropy f = Iz/Ix but different micro

  1. Mastoid obliteration using 3D PCL scaffold in combination with alginate and rhBMP-2.

    PubMed

    Jang, Chul Ho; Kim, Min Seong; Cho, Yong Beom; Jang, Yoon Seok; Kim, Geun Hyung

    2013-11-01

    Various materials, both biological and alloplastic, have been used for mastoid obliteration after canal wall-down mastoidectomy in chronic otitis media. The purpose of this study is to investigate the osteoinductive potential of PCL scaffolds in mastoid obliteration, and to test that osteoinductivity can be enhanced by coating PCL with alginate and rhBMP-2. The in vitro biocompatibilities of the scaffolds were examined using osteoblast-like cells (MG63). Cell-morphology and calcium deposition were assessed. Based on scanning electron microscope (SEM) images, the cells grew sporadically on the surfaces of the struts in the PCL scaffold, while the entire struts of the PCL/alginate/BMP-2 scaffold was covered with the cells. Furthermore, the PCL/alginate/BMP-2 scaffold showed significantly higher calcium deposition than the PCL/alginate scaffold. Micro-CT showed osteogenesis in the pores of the 3D PCL scaffold in the experimental group, compared to the control group. Confocal microscopic findings showed that the honeycomb appearance of the PCL structure remained in the control group (pure PCL), but significant amount of bone remodeling in the experimental group (PCL/alginate/BMP-2). Histomorphometric analysis showed that the experimental group demonstrated a significantly higher amount (p=0.014) of new bone formation with 50.2 ± 6.5% (mean ± SD), compared to 10.2 ± 3.5% for the control group. Based on these in vitro and in vivo results, the use of the PCL/alginate/BMP-2 scaffold seemed to be a promising technique for the mastoid obliteration.

  2. Production of new 3D scaffolds for bone tissue regeneration by rapid prototyping.

    PubMed

    Fradique, R; Correia, T R; Miguel, S P; de Sá, K D; Figueira, D R; Mendonça, A G; Correia, I J

    2016-04-01

    The incidence of bone disorders, whether due to trauma or pathology, has been trending upward with the aging of the worldwide population. The currently available treatments for bone injuries are rather limited, involving mainly bone grafts and implants. A particularly promising approach for bone regeneration uses rapid prototyping (RP) technologies to produce 3D scaffolds with highly controlled structure and orientation, based on computer-aided design models or medical data. Herein, tricalcium phosphate (TCP)/alginate scaffolds were produced using RP and subsequently their physicochemical, mechanical and biological properties were characterized. The results showed that 60/40 of TCP and alginate formulation was able to match the compression and present a similar Young modulus to that of trabecular bone while presenting an adequate biocompatibility. Moreover, the biomineralization ability, roughness and macro and microporosity of scaffolds allowed cell anchoring and proliferation at their surface, as well as cell migration to its interior, processes that are fundamental for osteointegration and bone regeneration.

  3. Hepatocyte behavior within three-dimensional porous alginate scaffolds.

    PubMed

    Glicklis, R; Shapiro, L; Agbaria, R; Merchuk, J C; Cohen, S

    2000-02-01

    A potential approach to facilitate the performance of implanted hepatocytes is to enable their aggregation and re-expression of their differentiated function prior to implantation. Here we examined the behavior of freshly isolated rat adult hepatocytes seeded within a novel three-dimensional (3-D) scaffold based on alginate. The attractive features of this scaffold include a highly porous structure (sponge-like) with interconnecting pores, and pore sizes with diameters of 100-150 microm. Due to their hydrophilic nature, seeding hepatocytes onto the alginate sponges was efficient. DNA measurements showed that the total cell number within the sponges did not change over 2 weeks, indicating that hepatocytes do not proliferate under these culture conditions. Nearly all seeded cells maintained viability, according to the MTT assay. Within 24 h post-seeding, small clusters of viable cells, were seen scattered within the sponge. More than 90% of the seeded cells participated in the aggregation; the high efficiency is attributed to the non-adherent nature of alginate. The spheroids had smooth boundaries and by day 4 in culture reached an average diameter of 100 microm, which is at the same magnitude of the sponge pore size. The cells appeared to synthesize fibronectin which was deposited on the spheroids. No laminin or collagen type IV were detected in the deposit. The 3-D arrangement of hepatocytes within the alginate sponges promoted their functional expression; within a week the cells secreted the maximal albumin secretion rate of 60 microg albumin/10(6) cells/day. Urea secretion rate did not depend on cell aggregation and was similar to that obtained when hepatocytes were cultured on collagen type I coated dishes (100 microg/10(6) cells/day). Our studies show that alginate sponges can provide a conducive environment to facilitate the performance of cultured hepatocytes by enhancing their aggregation.

  4. Phage nanofibers induce vascularized osteogenesis in 3D printed bone scaffolds.

    PubMed

    Wang, Jianglin; Yang, Mingying; Zhu, Ye; Wang, Lin; Tomsia, Antoni P; Mao, Chuanbin

    2014-08-01

    A virus-activated matrix is developed to overcome the challenge of forming vascularized bone tissue. It is generated by filling a 3D printed bioceramic scaffold with phage nanofibers displaying high-density RGD peptide. After it is seeded with mesenchymal stem cells (MSCs) and implanted into a bone defect, the phage nanofibers induce osteogenesis and angiogenesis by activating endothelialization and osteogenic differentiation of MSCs.

  5. hiPS-MSCs differentiation towards fibroblasts on a 3D ECM mimicking scaffold

    PubMed Central

    Xu, Ruodan; Taskin, Mehmet Berat; Rubert, Marina; Seliktar, Dror; Besenbacher, Flemming; Chen, Menglin

    2015-01-01

    Fibroblasts are ubiquitous cells that constitute the stroma of virtually all tissues and play vital roles in homeostasis. The poor innate healing capacity of fibroblastic tissues is attributed to the scarcity of fibroblasts as collagen-producing cells. In this study, we have developed a functional ECM mimicking scaffold that is capable to supply spatial allocation of stem cells as well as anchorage and storage of growth factors (GFs) to direct stem cells differentiate towards fibroblasts. Electrospun PCL fibers were embedded in a PEG-fibrinogen (PF) hydrogel, which was infiltrated with connective tissue growth factor (CTGF) to form the 3D nanocomposite PFP-C. The human induced pluripotent stem cells derived mesenchymal stem cells (hiPS-MSCs) with an advance in growth over adult MSCs were applied to validate the fibrogenic capacity of the 3D nanocomposite scaffold. The PFP-C scaffold was found not only biocompatible with the hiPS-MSCs, but also presented intriguingly strong fibroblastic commitments, to an extent comparable to the positive control, tissue culture plastic surfaces (TCP) timely refreshed with 100% CTGF. The novel scaffold presented not only biomimetic ECM nanostructures for homing stem cells, but also sufficient cell-approachable bio-signaling cues, which may synergistically facilitate the control of stem cell fates for regenerative therapies. PMID:25684543

  6. Tailored Surface Treatment of 3D Printed Porous Ti6Al4V by Microarc Oxidation for Enhanced Osseointegration via Optimized Bone In-Growth Patterns and Interlocked Bone/Implant Interface.

    PubMed

    Xiu, Peng; Jia, Zhaojun; Lv, Jia; Yin, Chuan; Cheng, Yan; Zhang, Ke; Song, Chunli; Leng, Huijie; Zheng, Yufeng; Cai, Hong; Liu, Zhongjun

    2016-07-20

    3D printed porous titanium (Ti) holds enormous potential for load-bearing orthopedic applications. Although the 3D printing technique has good control over the macro-sturctures of porous Ti, the surface properties that affect tissue response are beyond its control, adding the need for tailored surface treatment to improve its osseointegration capacity. Here, the one step microarc oxidation (MAO) process was applied to a 3D printed porous Ti6Al4V (Ti64) scaffold to endow the scaffold with a homogeneous layer of microporous TiO2 and significant amounts of amorphous calcium-phosphate. Following the treatment, the porous Ti64 scaffolds exhibited a drastically improved apatite forming ability, cyto-compatibility, and alkaline phosphatase activity. In vivo test in a rabbit model showed that the bone in-growth at the untreated scaffold was in a pattern of distance osteogenesis by which bone formed only at the periphery of the scaffold. In contrast, the bone in-growth at the MAO-treated scaffold exhibited a pattern of contact osteogenesis by which bone formed in situ on the entire surface of the scaffold. This pattern of bone in-growth significantly increased bone formation both in and around the scaffold possibly through enhancement of bone formation and disruption of bone remodeling. Moreover, the implant surface of the MAO-treated scaffold interlocked with the bone tissues through the fabricated microporous topographies to generate a stronger bone/implant interface. The increased osteoinetegration strength was further proven by a push out test. MAO exhibits a high efficiency in the enhancement of osteointegration of porous Ti64 via optimizing the patterns of bone in-growth and bone/implant interlocking. Therefore, post-treatment of 3D printed porous Ti64 with MAO technology might open up several possibilities for the development of bioactive customized implants in orthopedic applications. PMID:27341499

  7. Tailored Surface Treatment of 3D Printed Porous Ti6Al4V by Microarc Oxidation for Enhanced Osseointegration via Optimized Bone In-Growth Patterns and Interlocked Bone/Implant Interface.

    PubMed

    Xiu, Peng; Jia, Zhaojun; Lv, Jia; Yin, Chuan; Cheng, Yan; Zhang, Ke; Song, Chunli; Leng, Huijie; Zheng, Yufeng; Cai, Hong; Liu, Zhongjun

    2016-07-20

    3D printed porous titanium (Ti) holds enormous potential for load-bearing orthopedic applications. Although the 3D printing technique has good control over the macro-sturctures of porous Ti, the surface properties that affect tissue response are beyond its control, adding the need for tailored surface treatment to improve its osseointegration capacity. Here, the one step microarc oxidation (MAO) process was applied to a 3D printed porous Ti6Al4V (Ti64) scaffold to endow the scaffold with a homogeneous layer of microporous TiO2 and significant amounts of amorphous calcium-phosphate. Following the treatment, the porous Ti64 scaffolds exhibited a drastically improved apatite forming ability, cyto-compatibility, and alkaline phosphatase activity. In vivo test in a rabbit model showed that the bone in-growth at the untreated scaffold was in a pattern of distance osteogenesis by which bone formed only at the periphery of the scaffold. In contrast, the bone in-growth at the MAO-treated scaffold exhibited a pattern of contact osteogenesis by which bone formed in situ on the entire surface of the scaffold. This pattern of bone in-growth significantly increased bone formation both in and around the scaffold possibly through enhancement of bone formation and disruption of bone remodeling. Moreover, the implant surface of the MAO-treated scaffold interlocked with the bone tissues through the fabricated microporous topographies to generate a stronger bone/implant interface. The increased osteoinetegration strength was further proven by a push out test. MAO exhibits a high efficiency in the enhancement of osteointegration of porous Ti64 via optimizing the patterns of bone in-growth and bone/implant interlocking. Therefore, post-treatment of 3D printed porous Ti64 with MAO technology might open up several possibilities for the development of bioactive customized implants in orthopedic applications.

  8. Development of polycaprolactone/chitosan blend porous scaffolds.

    PubMed

    Wan, Ying; Xiao, Bo; Dalai, Siqin; Cao, Xiaoying; Wu, Quan

    2009-03-01

    Polycaprolactone (PCL) and chitosan were blended to fabricate porous scaffolds for tissue-engineering applications by employing a concentrated acetic acid solution as solvent and salt particles as porogen. These scaffolds showed well-controlled and interconnected porous structures. The pore size and porosity of the scaffolds could be effectively modulated by selecting appropriate amounts and sizes of porogen. The results obtained from compressive mechanical measurements indicated that PCL/chitosan could basically retain their strength in their dry state compared to individual components. In a hydrated state, their compressive stress and modulus could be still well maintained even though the weight ratio of chitosan reached around 50 wt%. PMID:18987952

  9. Engineered porous scaffolds for periprosthetic infection prevention.

    PubMed

    Iviglia, Giorgio; Cassinelli, Clara; Bollati, Daniele; Baino, Francesco; Torre, Elisa; Morra, Marco; Vitale-Brovarone, Chiara

    2016-11-01

    Periprosthetic infection is a consequence of implant insertion procedures and strategies for its prevention involve either an increase in the rate of new bone formation or the release of antibiotics such as vancomycin. In this work we combined both strategies and developed a novel, multifunctional three-dimensional porous scaffold that was produced using hydroxyapatite (HA) and β-tricalcium phosphate (β-TCP), coupled with a pectin (PEC)-chitosan (CHIT) polyelectrolyte (PEI), and loaded with vancomycin (VCA). By this approach, a controlled vancomycin release was achieved and serial bacterial dilution test demonstrated that, after 1week, the engineered construct still inhibits the bacterial growth. Degradation tests show an excellent behavior in a physiological and acidic environment (<10% of mass loss). Furthermore, the PEI coating shows an anti-inflammatory response, and good cell proliferation and migration were demonstrated in vitro using osteoblast SAOS-2 cell line. This new engineered construct exhibits excellent properties both as an antibacterial material and as a stimulator of bone formation, which makes it a good candidate to contrast periprosthetic infection. PMID:27524071

  10. Physicochemical properties of 3D collagen-CS scaffolds for potential use in neural tissue engineering.

    PubMed

    Pietrucha, Krystyna

    2015-09-01

    Collagen-based composite scaffolds have considerable potential due to their well-known ability to regenerate skin, bone and cartilage. However, the precise composition and structure of scaffolds that optimize their interaction with neural cells remains incompletely understood and yet to be explored. In the present study, a new family of bi-component 3D scaffolds consisting of collagen (Col) and chondroitin sulphate (CS) were synthesized using a two-stage process: multiple freeze-drying followed by carbodiimide modification. Col-CS matrices had an average pore diameter of 31 μm and a relatively high surface area to pore volume ratio. Importantly, the FTIR data indicated that the ratio between the intensity of amide III and 1452 cm(-1) for Col-CS scaffold was 0.87, which indicates that the Col triple helix was preserved during the formation of the bond between Col and CS. All experiments also clearly showed that the Col-CS matrices have a lower enzyme sensitivity and higher thermal resistance than Col alone. These differences are likely due to the relatively large amount of CS in the collagen sponges, which hinders access for attack at specific active sites of the Col triple helix. Improved binary composite scaffolds were designed for neural tissue engineering applications.

  11. Chronic Label-free Volumetric Photoacoustic Microscopy of Melanoma Cells in Three-Dimensional Porous Scaffolds

    PubMed Central

    Zhang, Yu; Cai, Xin; Choi, Sung-Wook; Kim, Chulhong; Wang, Lihong V.; Xia, Younan

    2010-01-01

    Visualizing cells in three-dimensional (3D) scaffolds has been one of the major challenges in tissue engineering. Most current imaging modalities either suffer from poor penetration depth or require exogenous contrast agents. Here, we demonstrate photoacoustic microscopy (PAM) of the spatial distribution and temporal proliferation of cells inside three-dimensional porous scaffolds with thicknesses over 1 mm. Specifically, we evaluated the effects of seeding and culture methods on the spatial distribution of melanoma cells. Spatial distribution of the cells in the scaffold was well-resolved in PAM images. Moreover, the number of cells in the scaffold was quantitatively measured from the as-obtained volumetric information. The cell proliferation profile obtained from PAM correlated well with what was obtained using the traditional 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. PMID:20727581

  12. Interfacing polymeric scaffolds with primary pancreatic ductal adenocarcinoma cells to develop 3D cancer models

    PubMed Central

    Ricci, Claudio; Mota, Carlos; Moscato, Stefania; D’Alessandro, Delfo; Ugel, Stefano; Sartoris, Silvia; Bronte, Vincenzo; Boggi, Ugo; Campani, Daniela; Funel, Niccola; Moroni, Lorenzo; Danti, Serena

    2014-01-01

    We analyzed the interactions between human primary cells from pancreatic ductal adenocarcinoma (PDAC) and polymeric scaffolds to develop 3D cancer models useful for mimicking the biology of this tumor. Three scaffold types based on two biocompatible polymeric formulations, such as poly(vinyl alcohol)/gelatin (PVA/G) mixture and poly(ethylene oxide terephthalate)/poly(butylene terephthalate) (PEOT/PBT) copolymer, were obtained via different techniques, namely, emulsion and freeze-drying, compression molding followed by salt leaching, and electrospinning. In this way, primary PDAC cells interfaced with different pore topographies, such as sponge-like pores of different shape and size or nanofiber interspaces. The aim of this study was to investigate the influence played by the scaffold architecture over cancerous cell growth and function. In all scaffolds, primary PDAC cells showed good viability and synthesized tumor-specific metalloproteinases (MMPs) such as MMP-2, and MMP-9. However, only sponge-like pores, obtained via emulsion-based and salt leaching-based techniques allowed for an organized cellular aggregation very similar to the native PDAC morphological structure. Differently, these cell clusters were not observed on PEOT/PBT electrospun scaffolds. MMP-2 and MMP-9, as active enzymes, resulted to be increased in PVA/G and PEOT/PBT sponges, respectively. These findings suggested that spongy scaffolds supported the generation of pancreatic tumor models with enhanced aggressiveness. In conclusion, primary PDAC cells showed diverse behaviors while interacting with different scaffold types that can be potentially exploited to create stage-specific pancreatic cancer models likely to provide new knowledge on the modulation and drug susceptibility of MMPs. PMID:25482337

  13. Interfacing polymeric scaffolds with primary pancreatic ductal adenocarcinoma cells to develop 3D cancer models.

    PubMed

    Ricci, Claudio; Mota, Carlos; Moscato, Stefania; D'Alessandro, Delfo; Ugel, Stefano; Sartoris, Silvia; Bronte, Vincenzo; Boggi, Ugo; Campani, Daniela; Funel, Niccola; Moroni, Lorenzo; Danti, Serena

    2014-01-01

    We analyzed the interactions between human primary cells from pancreatic ductal adenocarcinoma (PDAC) and polymeric scaffolds to develop 3D cancer models useful for mimicking the biology of this tumor. Three scaffold types based on two biocompatible polymeric formulations, such as poly(vinyl alcohol)/gelatin (PVA/G) mixture and poly(ethylene oxide terephthalate)/poly(butylene terephthalate) (PEOT/PBT) copolymer, were obtained via different techniques, namely, emulsion and freeze-drying, compression molding followed by salt leaching, and electrospinning. In this way, primary PDAC cells interfaced with different pore topographies, such as sponge-like pores of different shape and size or nanofiber interspaces. The aim of this study was to investigate the influence played by the scaffold architecture over cancerous cell growth and function. In all scaffolds, primary PDAC cells showed good viability and synthesized tumor-specific metalloproteinases (MMPs) such as MMP-2, and MMP-9. However, only sponge-like pores, obtained via emulsion-based and salt leaching-based techniques allowed for an organized cellular aggregation very similar to the native PDAC morphological structure. Differently, these cell clusters were not observed on PEOT/PBT electrospun scaffolds. MMP-2 and MMP-9, as active enzymes, resulted to be increased in PVA/G and PEOT/PBT sponges, respectively. These findings suggested that spongy scaffolds supported the generation of pancreatic tumor models with enhanced aggressiveness. In conclusion, primary PDAC cells showed diverse behaviors while interacting with different scaffold types that can be potentially exploited to create stage-specific pancreatic cancer models likely to provide new knowledge on the modulation and drug susceptibility of MMPs.

  14. Hierarchical bioceramic scaffolds with 3D-plotted macropores and mussel-inspired surface nanolayers for stimulating osteogenesis.

    PubMed

    Xu, Mengchi; Zhai, Dong; Xia, Lunguo; Li, Hong; Chen, Shiyi; Fang, Bing; Chang, Jiang; Wu, Chengtie

    2016-07-14

    The hierarchical structure of biomaterials plays an important role in the process of tissue reconstruction and regeneration. 3D-plotted scaffolds have been widely used for bone tissue engineering due to their controlled macropore structure and mechanical properties. However, the lack of micro- or nano-structures on the strut surface of 3D-plotted scaffolds, especially for bioceramic scaffolds, limits their biological activity. Inspired by the adhesive versatility of mussels and the active ion-chelating capacity of polydopamine, we set out to prepare a hierarchical bioceramic scaffold with controlled macropores and mussel-inspired surface nanolayers by combining the 3D-plotting technique with the polydopamine/apatite hybrid strategy in order to synergistically accelerate the osteogenesis and angiogenesis. β-Tricalcium phosphate (TCP) scaffolds were firstly 3D-plotted and then treated in dopamine-Tris/HCl and dopamine-SBF solutions to obtain TCP-DOPA-Tris and TCP-DOPA-SBF scaffolds, respectively. It was found that polydopamine/apatite hybrid nanolayers were formed on the surface of both TCP-DOPA-Tris and TCP-DOPA-SBF scaffolds and TCP-DOPA-SBF scaffolds induced apatite mineralization for the second time during the cell culture. As compared to TCP scaffolds, both TCP-DOPA-Tris and TCP-DOPA-SBF scaffolds significantly promoted the osteogenesis of bone marrow stromal cells (BMSCs) as well as the angiogenesis of human umbilical vein endothelial cells (HUVECs), and the TCP-DOPA-SBF group presented the highest in vitro osteogenic/angiogenic activity among the three groups. Furthermore, both TCP-DOPA-Tris and TCP-DOPA-SBF scaffolds significantly improved the formation of new bone in vivo as compared to TCP scaffolds without a nanostructured surface. Our results suggest that the utilization of a mussel-inspired Ca, P-chelated polydopamine nanolayer on 3D-plotted bioceramic scaffolds is a viable and effective strategy to construct a hierarchical structure for synergistically

  15. Digital micromirror device (DMD)-based 3D printing of poly(propylene fumarate) scaffolds.

    PubMed

    Mott, Eric J; Busso, Mallory; Luo, Xinyi; Dolder, Courtney; Wang, Martha O; Fisher, John P; Dean, David

    2016-04-01

    Our recent investigations into the 3D printing of poly(propylene fumarate) (PPF), a linear polyester, using a DMD-based system brought us to a resin that used titanium dioxide (TiO2) as an ultraviolet (UV) filter for controlling cure depth. However, this material hindered the 3D printing process due to undesirable lateral or "dark" curing (i.e., in areas not exposed to light from the DMD chip). Well known from its use in sunscreen, another UV filter, oxybenzone, has previously been used in conjunction with TiO2. In this study we hypothesize that combining these two UV filters will result in a synergistic effect that controls cure depth and avoids dark cure. A resin mixture (i.e., polymer, initiator, UV filters) was identified that worked well. The resin was then further characterized through mechanical testing, cure testing, and cytotoxicity testing to investigate its use as a material for bone tissue engineering scaffolds. Results show that the final resin eliminated dark cure as shown through image analysis. Mechanically the new scaffolds proved to be far weaker than those printed from previous resins, with compressive strengths of 7.8 ± 0.5 MPa vs. 36.5 ± 1.6 MPa, respectively. The new scaffolds showed a 90% reduction in elastic modulus and a 74% increase in max strain. These properties may be useful in tissue engineering applications where resorption is required. Initial cytotoxicity evaluation was negative. As hypothesized, the use of TiO2 and oxybenzone showed synergistic effects in the 3D printing of PPF tissue engineering scaffolds. PMID:26838854

  16. Digital micromirror device (DMD)-based 3D printing of poly(propylene fumarate) scaffolds.

    PubMed

    Mott, Eric J; Busso, Mallory; Luo, Xinyi; Dolder, Courtney; Wang, Martha O; Fisher, John P; Dean, David

    2016-04-01

    Our recent investigations into the 3D printing of poly(propylene fumarate) (PPF), a linear polyester, using a DMD-based system brought us to a resin that used titanium dioxide (TiO2) as an ultraviolet (UV) filter for controlling cure depth. However, this material hindered the 3D printing process due to undesirable lateral or "dark" curing (i.e., in areas not exposed to light from the DMD chip). Well known from its use in sunscreen, another UV filter, oxybenzone, has previously been used in conjunction with TiO2. In this study we hypothesize that combining these two UV filters will result in a synergistic effect that controls cure depth and avoids dark cure. A resin mixture (i.e., polymer, initiator, UV filters) was identified that worked well. The resin was then further characterized through mechanical testing, cure testing, and cytotoxicity testing to investigate its use as a material for bone tissue engineering scaffolds. Results show that the final resin eliminated dark cure as shown through image analysis. Mechanically the new scaffolds proved to be far weaker than those printed from previous resins, with compressive strengths of 7.8 ± 0.5 MPa vs. 36.5 ± 1.6 MPa, respectively. The new scaffolds showed a 90% reduction in elastic modulus and a 74% increase in max strain. These properties may be useful in tissue engineering applications where resorption is required. Initial cytotoxicity evaluation was negative. As hypothesized, the use of TiO2 and oxybenzone showed synergistic effects in the 3D printing of PPF tissue engineering scaffolds.

  17. Fabrication of 3D Scaffolds with Nano-Hydroxyapatite for Improving the Preosteoblast Cell-Biological Performance.

    PubMed

    Roh, Hee-Sang; Myung, Sung-Woon; Jung, Sang-Chul; Kim, Byung-Hoon

    2015-08-01

    Three-dimensional (3D) scaffolds fabricated by rapid prototyping techniques have many merits for tissue engineering applications, due to its controllable properties such as porosity, pore size and structural shape. Nonetheless, low cell seeding efficiency remains drawback. In this study, poly-caprolactone (PCL) composite 3D extruded scaffolds were modified with nano hydroxyapatite (n-HAp). PCL/n-HAp 3D scaffold surface was treated with oxygen plasma to improve the preosteoblast cell seeding efficiency and proliferation. The results indicate that oxygen plasma is useful technique to improve the cell affinity.

  18. Electrical and Neurotrophin Enhancement of Neurite Outgrowth within a 3D Collagen Scaffold

    PubMed Central

    Adams, Robert D.; Rendell, Sara R.; Counts, Lauren R.; Papke, Jason B.; Willits, Rebecca K.; Harkins, Amy B.

    2016-01-01

    Electrical and chemical stimulation have been studied as potent mechanisms of enhancing nerve regeneration and wound healing. However, it remains unclear how electrical stimuli affect nerve growth, particularly in the presence of neurotrophic factors. The objective of this study was to explore (1) the effect of brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) supplementation to support neurite outgrowth in a 3D scaffold, and (2) the effect of brief, low voltage, electrical stimulation (ES) on neurite outgrowth prior to neurotrophin supplementation. Dissociated E11 chick dorsal root ganglia (DRG) were seeded within a 1.5 mg/mL type-I collagen scaffold. For neurotrophin treatments, scaffolds were incubated for 24 hrs in culture media containing nerve growth factor (NGF, 10 ng/mL) or BDNF (200 ng/mL), or both. For ES groups, scaffolds containing neurons were stimulated for 10 min at 8–10 V/m DC, then incubated for 24 hrs with neurotrophin. Fixed and labeled neurons were imaged to measure neurite growth and directionality. BDNF supplementation was not as effective as NGF at supporting DRG neurite outgrowth. ES prior to NGF supplementation improved DRG neurite outgrowth compared to NGF alone. This combination of brief ES with NGF treatment was the most effective treatment compared to NGF or BDNF alone. Brief ES had no impact on neurite directionality in the 3D scaffolds. These results demonstrate that ES improves neurite outgrowth in the presence of neurotrophins, and could provide a potential therapeutic approach to improve nerve regeneration when coupled with neurotrophin treatment. PMID:24710795

  19. Additive manufactured polymeric 3D scaffolds with tailored surface topography influence mesenchymal stromal cells activity.

    PubMed

    Neves, Sara C; Mota, Carlos; Longoni, Alessia; Barrias, Cristina C; Granja, Pedro L; Moroni, Lorenzo

    2016-06-01

    Additive manufactured three-dimensional (3D) scaffolds with tailored surface topography constitute a clear advantage in tissue regeneration strategies to steer cell behavior. 3D fibrous scaffolds of poly(ethylene oxide terephthalate)/poly(butylene terephthalate) block copolymer presenting different fiber surface features were successfully fabricated by additive manufacturing combined with wet-spinning, in a single step, without any post-processing. The optimization of the processing parameters, mainly driven by different solvent/non-solvent combinations, led to four distinct scaffold types, with average surface roughness values ranging from 0.071 ± 0.012 μm to 1.950 ± 0.553 μm, average pore sizes in the x- and y-axis between 351.1 ± 33.6 μm and 396.1 ± 32.3 μm, in the z-axis between 36.5 ± 5.3 μm and 70.7 ± 8.8 μm, average fiber diameters between 69.4 ± 6.1 μm and 99.0 ± 9.4 μm, and porosity values ranging from 60.2 ± 0.8% to 71.7 ± 2.6%. Human mesenchymal stromal cells (hMSCs) cultured on these scaffolds adhered, proliferated, and produced endogenous extracellular matrix. The effect of surface roughness and topography on hMSCs differentiation was more evident for cells seeded at lower density, where the percentage of cells in direct contact with the surface was higher compared to more densely seeded scaffolds. Under osteogenic conditions, lower surface roughness values (0.227 ± 0.035 μm) had a synergistic effect on hMSCs behavior, while chondrogenesis was favored on rougher surfaces (1.950 ± 0.553 μm). PMID:27219645

  20. Direct 3D powder printing of biphasic calcium phosphate scaffolds for substitution of complex bone defects.

    PubMed

    Castilho, Miguel; Moseke, Claus; Ewald, Andrea; Gbureck, Uwe; Groll, Jürgen; Pires, Inês; Teßmar, Jörg; Vorndran, Elke

    2014-03-01

    The 3D printing technique based on cement powders is an excellent method for the fabrication of individual and complex bone substitutes even in the case of large defects. The outstanding bone remodeling capacity of biphasic calcium phosphates (BCPs) containing hydroxyapatite (HA) as well as tricalcium phosphate (TCP) in varying ratios makes the adaption of powder systems resulting in BCP materials to this fabrication technique a desirable aim. This study presents the synthesis and characterization of a novel powder system for the 3D printing process, intended for the production of complexly shaped BCP scaffolds by a hydraulic setting reaction of calcium carbonate and TCP with phosphoric acid. The HA/TCP ratio in the specimens could be tailored by the calcium/phosphate ratio of the starting powder. The scaffolds could be fabricated with a dimensional accuracy of >96.5% and a minimal macro pore size of 300 µm. Independent of the phase composition the printed specimens showed a microporosity of approximately 68%, while the compressive strength strongly depended on the chemical composition and increased with rising TCP content in the scaffolds to a maximum of 1.81 MPa. Post-treatment of the scaffolds with a polylactic-co-glycolic acid-solution enhanced the mechanical properties by a factor of 8. In vitro studies showed that all BCP scaffolds were cytocompatible and enhanced the cell viability as well as the cell proliferation, as compared with pure TCP. Cell proliferation is even better on BCP when compared to HA and cell viability is in a similar range on these materials.

  1. Porous poly(ε-caprolactone) scaffolds for load-bearing tissue regeneration: solventless fabrication and characterization.

    PubMed

    Allaf, Rula M; Rivero, Iris V; Abidi, Noureddine; Ivanov, Ilia N

    2013-08-01

    Three-dimensional interconnected porous poly(ε-caprolactone) scaffolds have been prepared by a novel solventless scaffold fabrication approach combining cryomilling and compression molding/porogen leaching techniques. This study investigated the effects of processing parameters on scaffold morphology and properties for tissue regeneration. Specifically, the effects of molding temperature, cryomilling time, and porogen mix were examined. Fifty percentage of porous scaffolds were fabricated with a range of properties: mean pore size from ∼40 to 125 μm, water uptake from ∼50 to 86%, compressive modulus from ∼45 to 84 MPa, and compressive strength at 10% strain from ∼3 to 4 MPa. Addition of 60 wt % NaCl salt resulted in a ∼50% increase in porosity in multimodal pore-size structures that depended on the method of NaCl addition. Water uptake ranged from ∼61 to 197%, compressive modulus from ∼4 to 8.6 MPa, and compressive strength at 10% strain from ∼0.36 to 0.40 MPa. Results suggest that this approach provides a controllable strategy for the design and fabrication of 3D interconnected porous biodegradable scaffolds for load-bearing tissue regeneration.

  2. Low intensity pulse ultrasound stimulate chondrocytes growth in a 3-D alginate scaffold through improved porosity and permeability.

    PubMed

    Guo, Gepu; Lu, Lu; Ji, Hongfei; Ma, Yong; Dong, Rui; Tu, Juan; Guo, Xiasheng; Qiu, Yuanyuan; Wu, Junru; Zhang, Dong

    2015-04-01

    A 3-D scaffold culture system has been used to promote in producing functional chondrocytes for repairing damaged cartilage. In the present study, the low intensity pulse ultrasound (LIPUS) (P(-)=0, 0.055, 0.085 and 0.11 MPa) was applied to improve the porosity and permeability of a 3-D alginate scaffold which was beneficial for the nutrition supply and metabolism during cell growth in 3-D alginate scaffold. The porosity and permeability of the scaffold was quantitatively analyzed based on scanning electron microscopy examination and fluorescence image observation. The results suggest that, for the scaffold exposed to LIPUS, its porosity and permeability could be significantly enhanced by the increasing LIPUS amplitude, which might be induced by the microstreaming shear stress generated by ultrasound-driven microbubble oscillations. Furthermore, the assessments of cell proliferation and collagen II expression confirmed that chondrocytes growth could be effectively promoted in 3-D alginate scaffolds treated by LIPUS, because of the improved scaffold porosity and permeability might benefit cell growth space and nutrition supply. It should also be noticed that appropriate LIPUS driving parameters should be adapted to achieve optimized chondrocytes culture effect in 3-D alginate scaffold. PMID:25543661

  3. Low intensity pulse ultrasound stimulate chondrocytes growth in a 3-D alginate scaffold through improved porosity and permeability.

    PubMed

    Guo, Gepu; Lu, Lu; Ji, Hongfei; Ma, Yong; Dong, Rui; Tu, Juan; Guo, Xiasheng; Qiu, Yuanyuan; Wu, Junru; Zhang, Dong

    2015-04-01

    A 3-D scaffold culture system has been used to promote in producing functional chondrocytes for repairing damaged cartilage. In the present study, the low intensity pulse ultrasound (LIPUS) (P(-)=0, 0.055, 0.085 and 0.11 MPa) was applied to improve the porosity and permeability of a 3-D alginate scaffold which was beneficial for the nutrition supply and metabolism during cell growth in 3-D alginate scaffold. The porosity and permeability of the scaffold was quantitatively analyzed based on scanning electron microscopy examination and fluorescence image observation. The results suggest that, for the scaffold exposed to LIPUS, its porosity and permeability could be significantly enhanced by the increasing LIPUS amplitude, which might be induced by the microstreaming shear stress generated by ultrasound-driven microbubble oscillations. Furthermore, the assessments of cell proliferation and collagen II expression confirmed that chondrocytes growth could be effectively promoted in 3-D alginate scaffolds treated by LIPUS, because of the improved scaffold porosity and permeability might benefit cell growth space and nutrition supply. It should also be noticed that appropriate LIPUS driving parameters should be adapted to achieve optimized chondrocytes culture effect in 3-D alginate scaffold.

  4. Novel biodegradable porous scaffold applied to skin regeneration.

    PubMed

    Wang, Hui-Min; Chou, Yi-Ting; Wen, Zhi-Hong; Wang, Chau-Zen; Wang, Zhao-Ren; Chen, Chun-Hong; Ho, Mei-Ling

    2013-01-01

    Skin wound healing is an important lifesaving issue for massive lesions. A novel porous scaffold with collagen, hyaluronic acid and gelatin was developed for skin wound repair. The swelling ratio of this developed scaffold was assayed by water absorption capacity and showed a value of over 20 g water/g dried scaffold. The scaffold was then degraded in time- and dose-dependent manners by three enzymes: lysozyme, hyaluronidase and collagenase I. The average pore diameter of the scaffold was 132.5±8.4 µm measured from SEM images. With human skin cells growing for 7 days, the SEM images showed surface fractures on the scaffold due to enzymatic digestion, indicating the biodegradable properties of this scaffold. To simulate skin distribution, the human epidermal keratinocytes, melanocytes and dermal fibroblasts were seeded on the porous scaffold and the cross-section immunofluorescent staining demonstrated normal human skin layer distributions. The collagen amount was also quantified after skin cells seeding and presented an amount 50% higher than those seeded on culture wells. The in vivo histological results showed that the scaffold ameliorated wound healing, including decreasing neutrophil infiltrates and thickening newly generated skin compared to the group without treatments.

  5. Effect of Layer Thickness and Printing Orientation on Mechanical Properties and Dimensional Accuracy of 3D Printed Porous Samples for Bone Tissue Engineering

    PubMed Central

    Farzadi, Arghavan; Solati-Hashjin, Mehran; Asadi-Eydivand, Mitra; Abu Osman, Noor Azuan

    2014-01-01

    Powder-based inkjet 3D printing method is one of the most attractive solid free form techniques. It involves a sequential layering process through which 3D porous scaffolds can be directly produced from computer-generated models. 3D printed products' quality are controlled by the optimal build parameters. In this study, Calcium Sulfate based powders were used for porous scaffolds fabrication. The printed scaffolds of 0.8 mm pore size, with different layer thickness and printing orientation, were subjected to the depowdering step. The effects of four layer thicknesses and printing orientations, (parallel to X, Y and Z), on the physical and mechanical properties of printed scaffolds were investigated. It was observed that the compressive strength, toughness and Young's modulus of samples with 0.1125 and 0.125 mm layer thickness were more than others. Furthermore, the results of SEM and μCT analyses showed that samples with 0.1125 mm layer thickness printed in X direction have more dimensional accuracy and significantly close to CAD software based designs with predefined pore size, porosity and pore interconnectivity. PMID:25233468

  6. Effect of layer thickness and printing orientation on mechanical properties and dimensional accuracy of 3D printed porous samples for bone tissue engineering.

    PubMed

    Farzadi, Arghavan; Solati-Hashjin, Mehran; Asadi-Eydivand, Mitra; Abu Osman, Noor Azuan

    2014-01-01

    Powder-based inkjet 3D printing method is one of the most attractive solid free form techniques. It involves a sequential layering process through which 3D porous scaffolds can be directly produced from computer-generated models. 3D printed products' quality are controlled by the optimal build parameters. In this study, Calcium Sulfate based powders were used for porous scaffolds fabrication. The printed scaffolds of 0.8 mm pore size, with different layer thickness and printing orientation, were subjected to the depowdering step. The effects of four layer thicknesses and printing orientations, (parallel to X, Y and Z), on the physical and mechanical properties of printed scaffolds were investigated. It was observed that the compressive strength, toughness and Young's modulus of samples with 0.1125 and 0.125 mm layer thickness were more than others. Furthermore, the results of SEM and μCT analyses showed that samples with 0.1125 mm layer thickness printed in X direction have more dimensional accuracy and significantly close to CAD software based designs with predefined pore size, porosity and pore interconnectivity.

  7. Generation and transplantation of reprogrammed human neurons in the brain using 3D microtopographic scaffolds.

    PubMed

    Carlson, Aaron L; Bennett, Neal K; Francis, Nicola L; Halikere, Apoorva; Clarke, Stephen; Moore, Jennifer C; Hart, Ronald P; Paradiso, Kenneth; Wernig, Marius; Kohn, Joachim; Pang, Zhiping P; Moghe, Prabhas V

    2016-01-01

    Cell replacement therapy with human pluripotent stem cell-derived neurons has the potential to ameliorate neurodegenerative dysfunction and central nervous system injuries, but reprogrammed neurons are dissociated and spatially disorganized during transplantation, rendering poor cell survival, functionality and engraftment in vivo. Here, we present the design of three-dimensional (3D) microtopographic scaffolds, using tunable electrospun microfibrous polymeric substrates that promote in situ stem cell neuronal reprogramming, neural network establishment and support neuronal engraftment into the brain. Scaffold-supported, reprogrammed neuronal networks were successfully grafted into organotypic hippocampal brain slices, showing an ∼ 3.5-fold improvement in neurite outgrowth and increased action potential firing relative to injected isolated cells. Transplantation of scaffold-supported neuronal networks into mouse brain striatum improved survival ∼ 38-fold at the injection site relative to injected isolated cells, and allowed delivery of multiple neuronal subtypes. Thus, 3D microscale biomaterials represent a promising platform for the transplantation of therapeutic human neurons with broad neuro-regenerative relevance. PMID:26983594

  8. Generation and transplantation of reprogrammed human neurons in the brain using 3D microtopographic scaffolds

    PubMed Central

    Carlson, Aaron L.; Bennett, Neal K.; Francis, Nicola L.; Halikere, Apoorva; Clarke, Stephen; Moore, Jennifer C.; Hart, Ronald P.; Paradiso, Kenneth; Wernig, Marius; Kohn, Joachim; Pang, Zhiping P.; Moghe, Prabhas V.

    2016-01-01

    Cell replacement therapy with human pluripotent stem cell-derived neurons has the potential to ameliorate neurodegenerative dysfunction and central nervous system injuries, but reprogrammed neurons are dissociated and spatially disorganized during transplantation, rendering poor cell survival, functionality and engraftment in vivo. Here, we present the design of three-dimensional (3D) microtopographic scaffolds, using tunable electrospun microfibrous polymeric substrates that promote in situ stem cell neuronal reprogramming, neural network establishment and support neuronal engraftment into the brain. Scaffold-supported, reprogrammed neuronal networks were successfully grafted into organotypic hippocampal brain slices, showing an ∼3.5-fold improvement in neurite outgrowth and increased action potential firing relative to injected isolated cells. Transplantation of scaffold-supported neuronal networks into mouse brain striatum improved survival ∼38-fold at the injection site relative to injected isolated cells, and allowed delivery of multiple neuronal subtypes. Thus, 3D microscale biomaterials represent a promising platform for the transplantation of therapeutic human neurons with broad neuro-regenerative relevance. PMID:26983594

  9. Image-based analysis of the internal microstructure of bone replacement scaffolds fabricated by 3D printing

    NASA Astrophysics Data System (ADS)

    Irsen, Stephan H.; Leukers, Barbara; Bruckschen, Björn; Tille, Carsten; Seitz, Hermann; Beckmann, Felix; Müller, Bert

    2006-08-01

    Rapid Prototyping and especially the 3D printing, allows generating complex porous ceramic scaffolds directly from powders. Furthermore, these technologies allow manufacturing patient-specific implants of centimeter size with an internal pore network to mimic bony structures including vascularization. Besides the biocompatibility properties of the base material, a high degree of open, interconnected porosity is crucial for the success of the synthetic bone graft. Pores with diameters between 100 and 500 μm are the prerequisite for vascularization to supply the cells with nutrients and oxygen, because simple diffusion transport is ineffective. The quantification of porosity on the macro-, micro-, and nanometer scale using well-established techniques such as Hg-porosimetry and electron microscopy is restricted. Alternatively, we have applied synchrotron-radiation-based micro computed tomography (SRμCT) to determine the porosity with high precision and to validate the macroscopic internal structure of the scaffold. We report on the difficulties in intensity-based segmentation for nanoporous materials but we also elucidate the power of SRμCT in the quantitative analysis of the pores at the different length scales.

  10. The use of flow perfusion culture and subcutaneous implantation with fibroblast-seeded PLLA-collagen 3D scaffolds for abdominal wall repair.

    PubMed

    Pu, Fanrong; Rhodes, Nicholas P; Bayon, Yves; Chen, Rui; Brans, Gerben; Benne, Remco; Hunt, John A

    2010-05-01

    Highly cellularised 3D-tissue constructs designed to repair large, complex abdominal wall defects were prepared using poly (lactic acid) (PLLA)-collagen scaffolds in vitro using a flow perfusion bioreactor. The PLLA-collagen scaffolds had a unique structure consisting of a collagen sponge formed within the pores of a mechanically stable knitted mesh of PLLA. The effect of the flow perfusion bioreactor culturing conditions was investigated in vitro for 0, 7, 14 and 28 days on scaffolds seeded with dermal fibroblasts. The cultured constructs were subsequently studied subcutaneously (SC) in an in vivo animal model. The results of in vitro studies demonstrated that the perfusion system facilitated increased cell proliferation and homogenous distribution in the PLLA-collagen scaffolds compared to static conditions. A highly cellularised 3D-tissue construct was formed by 7 days incubation under perfusion conditions, with increased cellularity by the 28 day time point. The in vivo model demonstrated that implanting constructs with high cellularity resulted in exceptional cell stabilisation, with the survival of implanted cells and expression of the phenotypically-relevant extracellular matrix proteins collagen types I and III, studied by fluorescence in situ hybridisation (FISH) and immunohistochemistry. The implantation of this porous PPLA-collagen scaffold seeded with dermal fibroblasts following in vitro maturation using a flow perfusion bioreactor system suggests a significant advance over current state-of-the-art procedures for the reconstruction of large, complex abdominal wall tissue defects. PMID:20219244

  11. Polycaprolactone-Coated 3D Printed Tricalcium Phosphate Scaffolds for Bone Tissue Engineering: In Vitro Alendronate Release Behavior and Local Delivery Effect on In Vivo Osteogenesis

    PubMed Central

    2015-01-01

    The aim of this work was to evaluate the effect of in vitro alendronate (AD) release behavior through polycaprolactone (PCL) coating on in vivo bone formation using PCL-coated 3D printed interconnected porous tricalcium phosphate (TCP) scaffolds. Higher AD and Ca2+ ion release was observed at lower pH (5.0) than that at higher pH (7.4). AD and Ca2+ release, surface morphology, and phase analysis after release indicated a matrix degradation dominated AD release caused by TCP dissolution. PCL coating showed its effectiveness for controlled and sustained AD release. Six different scaffold compositions, namely, (i) TCP (bare TCP), (ii) TCP + AD (AD-coated TCP), (iii) TCP + PCL (PCL-coated TCP), (iv) TCP + PCL + AD, (v) TCP + AD + PCL, and (vi) TCP + AD + PCL + AD were tested in the distal femoral defect of Sprague–Dawley rats for 6 and 10 weeks. An excellent bone formation inside the micro and macro pores of the scaffolds was observed from histomorphology. Histomorphometric analysis revealed maximum new bone formation in TCP + AD + PCL scaffolds after 6 weeks. No adverse effect of PCL on bioactivity of TCP and in vivo bone formation was observed. All scaffolds with AD showed higher bone formation and reduced TRAP (tartrate resistant acid phosphatase) positive cells activity compared to bare TCP and TCP coated with only PCL. Bare TCP scaffolds showed the highest TRAP positive cells activity followed by TCP + PCL scaffolds, whereas TCP + AD scaffolds showed the lowest TRAP activity. A higher TRAP positive cells activity was observed in TCP + AD + PCL compared to TCP + AD scaffolds after 6 weeks. Our results show that in vivo local AD delivery from PCL-coated 3DP TCP scaffolds could further induce increased early bone formation. PMID:24826838

  12. Ligand scaffold hopping combining 3D maximal substructure search and molecular similarity

    PubMed Central

    Quintus, Flavien; Sperandio, Olivier; Grynberg, Julien; Petitjean, Michel; Tuffery, Pierre

    2009-01-01

    Background Virtual screening methods are now well established as effective to identify hit and lead candidates and are fully integrated in most drug discovery programs. Ligand-based approaches make use of physico-chemical, structural and energetics properties of known active compounds to search large chemical libraries for related and novel chemotypes. While 2D-similarity search tools are known to be fast and efficient, the use of 3D-similarity search methods can be very valuable to many research projects as integration of "3D knowledge" can facilitate the identification of not only related molecules but also of chemicals possessing distant scaffolds as compared to the query and therefore be more inclined to scaffolds hopping. To date, very few methods performing this task are easily available to the scientific community. Results We introduce a new approach (LigCSRre) to the 3D ligand similarity search of drug candidates. It combines a 3D maximum common substructure search algorithm independent on atom order with a tunable description of atomic compatibilities to prune the search and increase its physico-chemical relevance. We show, on 47 experimentally validated active compounds across five protein targets having different specificities, that for single compound search, the approach is able to recover on average 52% of the co-actives in the top 1% of the ranked list which is better than gold standards of the field. Moreover, the combination of several runs on a single protein target using different query active compounds shows a remarkable improvement in enrichment. Such Results demonstrate LigCSRre as a valuable tool for ligand-based screening. Conclusion LigCSRre constitutes a new efficient and generic approach to the 3D similarity screening of small compounds, whose flexible design opens the door to many enhancements. The program is freely available to the academics for non-profit research at: . PMID:19671127

  13. Use of stereolithography to manufacture critical-sized 3D biodegradable scaffolds for bone ingrowth.

    PubMed

    Cooke, Malcolm N; Fisher, John P; Dean, David; Rimnac, Clare; Mikos, Antonios G

    2003-02-15

    A novel approach to the manufacture of biodegradable polymeric scaffolds for tissue-engineering utilizing stereolithography (SLA) is presented. SLA is a three-dimensional (3D) printing method that uses an ultraviolet laser to photo-crosslink a liquid polymer substrate. The current generation of SLA devices provide a 3D printing resolution of 0.1 mm. The experiments utilized a biodegradable resin mixture of diethyl fumarate (DEF), poly(propylene fumarate) (PPF), and a photoinitiator, bisacylphosphine oxide (BAPO). The PPF is crosslinked with the use of the SLA's UV laser (325-nm wavelength). An SLA device was retrofitted with a custom fixture build tank enclosing an elevator-driven build table. A 3D prototype model testing the manufacturing control this device provides was created in a computer-aided-design package. The resulting geometric data were used to drive the SLA process, and a DEF/PPF prototype part was successfully manufactured. These scaffolds have application in the tissue engineering of bony substrates.

  14. Use of stereolithography to manufacture critical-sized 3D biodegradable scaffolds for bone ingrowth.

    PubMed

    Cooke, Malcolm N; Fisher, John P; Dean, David; Rimnac, Clare; Mikos, Antonios G

    2003-02-15

    A novel approach to the manufacture of biodegradable polymeric scaffolds for tissue-engineering utilizing stereolithography (SLA) is presented. SLA is a three-dimensional (3D) printing method that uses an ultraviolet laser to photo-crosslink a liquid polymer substrate. The current generation of SLA devices provide a 3D printing resolution of 0.1 mm. The experiments utilized a biodegradable resin mixture of diethyl fumarate (DEF), poly(propylene fumarate) (PPF), and a photoinitiator, bisacylphosphine oxide (BAPO). The PPF is crosslinked with the use of the SLA's UV laser (325-nm wavelength). An SLA device was retrofitted with a custom fixture build tank enclosing an elevator-driven build table. A 3D prototype model testing the manufacturing control this device provides was created in a computer-aided-design package. The resulting geometric data were used to drive the SLA process, and a DEF/PPF prototype part was successfully manufactured. These scaffolds have application in the tissue engineering of bony substrates. PMID:12516080

  15. 3D Hydrogel Scaffolds for Articular Chondrocyte Culture and Cartilage Generation

    PubMed Central

    Yang, Fan; Bhutani, Nidhi

    2015-01-01

    Human articular cartilage is highly susceptible to damage and has limited self-repair and regeneration potential. Cell-based strategies to engineer cartilage tissue offer a promising solution to repair articular cartilage. To select the optimal cell source for tissue repair, it is important to develop an appropriate culture platform to systematically examine the biological and biomechanical differences in the tissue-engineered cartilage by different cell sources. Here we applied a three-dimensional (3D) biomimetic hydrogel culture platform to systematically examine cartilage regeneration potential of juvenile, adult, and osteoarthritic (OA) chondrocytes. The 3D biomimetic hydrogel consisted of synthetic component poly(ethylene glycol) and bioactive component chondroitin sulfate, which provides a physiologically relevant microenvironment for in vitro culture of chondrocytes. In addition, the scaffold may be potentially used for cell delivery for cartilage repair in vivo. Cartilage tissue engineered in the scaffold can be evaluated using quantitative gene expression, immunofluorescence staining, biochemical assays, and mechanical testing. Utilizing these outcomes, we were able to characterize the differential regenerative potential of chondrocytes of varying age, both at the gene expression level and in the biochemical and biomechanical properties of the engineered cartilage tissue. The 3D culture model could be applied to investigate the molecular and functional differences among chondrocytes and progenitor cells from different stages of normal or aberrant development. PMID:26484414

  16. Two-photon polymerization of 3-D zirconium oxide hybrid scaffolds for long-term stem cell growth.

    PubMed

    Skoog, Shelby A; Nguyen, Alexander K; Kumar, Girish; Zheng, Jiwen; Goering, Peter L; Koroleva, Anastasia; Chichkov, Boris N; Narayan, Roger J

    2014-06-01

    Two-photon polymerization is a technique that involves simultaneous absorption of two photons from a femtosecond laser for selective polymerization of a photosensitive material. In this study, two-photon polymerization was used for layer-by-layer fabrication of 3-D scaffolds composed of an inorganic-organic zirconium oxide hybrid material. Four types of scaffold microarchitectures were created, which exhibit layers of parallel line features at various orientations as well as pores between the line features. Long-term cell culture studies involving human bone marrow stromal cells were conducted using these 3-D scaffolds. Cellular adhesion and proliferation were demonstrated on all of the scaffold types; tissuelike structure was shown to span the pores. This study indicates that two-photon polymerization may be used to create microstructured scaffolds out of an inorganic-organic zirconium oxide hybrid material for use in 3-D tissue culture systems.

  17. Two-Photon Lithography of 3D Nanocomposite Piezoelectric Scaffolds for Cell Stimulation.

    PubMed

    Marino, Attilio; Barsotti, Jonathan; de Vito, Giuseppe; Filippeschi, Carlo; Mazzolai, Barbara; Piazza, Vincenzo; Labardi, Massimiliano; Mattoli, Virgilio; Ciofani, Gianni

    2015-11-25

    In this letter, we report on the fabrication, the characterization, and the in vitro testing of structures suitable for cell culturing, prepared through two-photon polymerization of a nanocomposite resist. More in details, commercially available Ormocomp has been doped with piezoelectric barium titanate nanoparticles, and bioinspired 3D structures resembling trabeculae of sponge bone have been fabricated. After an extensive characterization, preliminary in vitro testing demonstrated that both the topographical and the piezoelectric cues of these scaffolds are able to enhance the differentiation process of human SaOS-2 cells. PMID:26548588

  18. Two-Photon Lithography of 3D Nanocomposite Piezoelectric Scaffolds for Cell Stimulation.

    PubMed

    Marino, Attilio; Barsotti, Jonathan; de Vito, Giuseppe; Filippeschi, Carlo; Mazzolai, Barbara; Piazza, Vincenzo; Labardi, Massimiliano; Mattoli, Virgilio; Ciofani, Gianni

    2015-11-25

    In this letter, we report on the fabrication, the characterization, and the in vitro testing of structures suitable for cell culturing, prepared through two-photon polymerization of a nanocomposite resist. More in details, commercially available Ormocomp has been doped with piezoelectric barium titanate nanoparticles, and bioinspired 3D structures resembling trabeculae of sponge bone have been fabricated. After an extensive characterization, preliminary in vitro testing demonstrated that both the topographical and the piezoelectric cues of these scaffolds are able to enhance the differentiation process of human SaOS-2 cells.

  19. Engineering Human TMJ Discs with Protein-Releasing 3D-Printed Scaffolds.

    PubMed

    Legemate, K; Tarafder, S; Jun, Y; Lee, C H

    2016-07-01

    The temporomandibular joint (TMJ) disc is a heterogeneous fibrocartilaginous tissue positioned between the mandibular condyle and glenoid fossa of the temporal bone, with important roles in TMJ functions. Tissue engineering TMJ discs has emerged as an alternative approach to overcoming limitations of current treatments for TMJ disorders. However, the anisotropic collagen orientation and inhomogeneous fibrocartilaginous matrix distribution present challenges in the tissue engineering of functional TMJ discs. Here, we developed 3-dimensional (3D)-printed anatomically correct scaffolds with region-variant microstrand alignment, mimicking anisotropic collagen alignment in the TMJ disc and corresponding mechanical properties. Connective tissue growth factor (CTGF) and transforming growth factor beta 3 (TGFβ3) were then delivered in the scaffolds by spatially embedding CTGF- or TGFβ3-encapsulated microspheres (µS) to reconstruct the regionally variant fibrocartilaginous matrix in the native TMJ disc. When cultured with human mesenchymal stem/progenitor cells (MSCs) for 6 wk, 3D-printed scaffolds with CTGF/TGFβ3-µS resulted in a heterogeneous fibrocartilaginous matrix with overall distribution of collagen-rich fibrous structure in the anterior/posterior (AP) bands and fibrocartilaginous matrix in the intermediate zone, reminiscent of the native TMJ disc. High dose of CTGF/TGFβ3-µS (100 mg µS/g of scaffold) showed significantly more collagen II and aggrecan in the intermediate zone than a low dose (50 mg µS/g of scaffold). Similarly, a high dose of CTGF/TGFβ3-µS yielded significantly higher collagen I expression in the AP bands compared with the low-dose and empty µS. From stress relaxation tests, the ratio of relaxation modulus to instantaneous modulus was significantly smaller with CTGF/TGFβ3-µS than empty µS. Similarly, a significantly higher coefficient of viscosity was achieved with the high dose of CTGF/TGFβ3-µS compared with the low-dose and empty

  20. Chondrogenic regeneration using bone marrow clots and a porous polycaprolactone-hydroxyapatite scaffold by three-dimensional printing.

    PubMed

    Yao, Qingqiang; Wei, Bo; Liu, Nancy; Li, Chenshuang; Guo, Yang; Shamie, Arya Nick; Chen, James; Tang, Cheng; Jin, Chengzhe; Xu, Yan; Bian, Xiuwu; Zhang, Xinli; Wang, Liming

    2015-04-01

    Scaffolds play an important role in directing three-dimensional (3D) cartilage regeneration. Our recent study reported the potential advantages of bone marrow clots (MC) in promoting extracellular matrix (ECM) scaffold chondrogenic regeneration. The aim of this study is to build a new scaffold for MC, with improved characteristics in mechanics, shaping, and biodegradability, compared to our previous study. To address this issue, this study prepared a 3D porous polycaprolactone (PCL)-hydroxyapatite (HA) scaffold combined with MC (Group A), while the control group (Group B) utilized a bone marrow stem cell seeded PCL-HA scaffold. The results of in vitro cultures and in vivo implantation demonstrated that although an initial obstruction of nutrient exchange caused by large amounts of fibrin and erythrocytes led to a decrease in the ratio of live cells in Group A, these scaffolds also showed significant improvements in cell adhesion, proliferation, and chondrogenic differentiation with porous recanalization in the later culture, compared to Group B. After 4 weeks of in vivo implantation, Group A scaffolds have a superior performance in DNA content, Sox9 and RunX2 expression, cartilage lacuna-like cell and ECM accumulation, when compared to Group B. Furthermore, Group A scaffold size and mechanics were stable during in vitro and in vivo experiments, unlike the scaffolds in our previous study. Our results suggest that the combination with MC proved to be a highly efficient, reliable, and simple new method that improves the biological performance of 3D PCL-HA scaffold. The MC-PCL-HA scaffold is a candidate for future cartilage regeneration studies.

  1. Chondrogenic Regeneration Using Bone Marrow Clots and a Porous Polycaprolactone-Hydroxyapatite Scaffold by Three-Dimensional Printing

    PubMed Central

    Yao, Qingqiang; Wei, Bo; Liu, Nancy; Li, Chenshuang; Guo, Yang; Shamie, Arya Nick; Chen, James; Tang, Cheng; Jin, Chengzhe; Xu, Yan

    2015-01-01

    Scaffolds play an important role in directing three-dimensional (3D) cartilage regeneration. Our recent study reported the potential advantages of bone marrow clots (MC) in promoting extracellular matrix (ECM) scaffold chondrogenic regeneration. The aim of this study is to build a new scaffold for MC, with improved characteristics in mechanics, shaping, and biodegradability, compared to our previous study. To address this issue, this study prepared a 3D porous polycaprolactone (PCL)-hydroxyapatite (HA) scaffold combined with MC (Group A), while the control group (Group B) utilized a bone marrow stem cell seeded PCL-HA scaffold. The results of in vitro cultures and in vivo implantation demonstrated that although an initial obstruction of nutrient exchange caused by large amounts of fibrin and erythrocytes led to a decrease in the ratio of live cells in Group A, these scaffolds also showed significant improvements in cell adhesion, proliferation, and chondrogenic differentiation with porous recanalization in the later culture, compared to Group B. After 4 weeks of in vivo implantation, Group A scaffolds have a superior performance in DNA content, Sox9 and RunX2 expression, cartilage lacuna-like cell and ECM accumulation, when compared to Group B. Furthermore, Group A scaffold size and mechanics were stable during in vitro and in vivo experiments, unlike the scaffolds in our previous study. Our results suggest that the combination with MC proved to be a highly efficient, reliable, and simple new method that improves the biological performance of 3D PCL-HA scaffold. The MC-PCL-HA scaffold is a candidate for future cartilage regeneration studies. PMID:25530453

  2. Creation of a long-lifespan ciliated epithelial tissue structure using a 3D collagen scaffold

    PubMed Central

    Wang, Yuchi; Wong, Lid B.; Mao, Hua

    2009-01-01

    We describe a method of using a 3D collagen gel scaffold applied at the air-liquid interface to culture dissociated primary tracheal-bronchial ciliated cells into a ciliated epithelial tissue structure (CETS). This 3D collagen gel culture system enables the induction of ciliogenesis and continuously provides support, maintenance, development, differentiation and propagation for the growth of cilia into the CETS. The CETS developed by this system resembles the ciliary metachronal motility and morphological, histological and physiopharmacological characteristics of cells found in native and in vivo ciliated epithelia. The CETS can be sustained for months with a straightforward and simple maintenance protocol. The integrity of the functional ciliary activity of this CETS enables the evaluation of long-term effects of many pulmonary drug candidates without using animals. PMID:19836831

  3. A Tunable Scaffold of Microtubular Graphite for 3D Cell Growth

    PubMed Central

    2016-01-01

    Aerographite (AG) is a novel carbon-based material that exists as a self-supportive 3D network of interconnected hollow microtubules. It can be synthesized in a variety of architectures tailored by the growth conditions. This flexibility in creating structures presents interesting bioengineering possibilities such as the generation of an artificial extracellular matrix. Here we have explored the feasibility and potential of AG as a scaffold for 3D cell growth employing cyclic RGD (cRGD) peptides coupled to poly(ethylene glycol) (PEG) conjugated phospholipids for surface functionalization to promote specific adhesion of fibroblast cells. Successful growth and invasion of the bulk material was followed over a period of 4 days. PMID:27258400

  4. Coupling curvature-dependent and shear stress-stimulated neotissue growth in dynamic bioreactor cultures: a 3D computational model of a complete scaffold.

    PubMed

    Guyot, Y; Papantoniou, I; Luyten, F P; Geris, L

    2016-02-01

    The main challenge in tissue engineering consists in understanding and controlling the growth process of in vitro cultured neotissues toward obtaining functional tissues. Computational models can provide crucial information on appropriate bioreactor and scaffold design but also on the bioprocess environment and culture conditions. In this study, the development of a 3D model using the level set method to capture the growth of a microporous neotissue domain in a dynamic culture environment (perfusion bioreactor) was pursued. In our model, neotissue growth velocity was influenced by scaffold geometry as well as by flow- induced shear stresses. The neotissue was modeled as a homogenous porous medium with a given permeability, and the Brinkman equation was used to calculate the flow profile in both neotissue and void space. Neotissue growth was modeled until the scaffold void volume was filled, thus capturing already established experimental observations, in particular the differences between scaffold filling under different flow regimes. This tool is envisaged as a scaffold shape and bioprocess optimization tool with predictive capacities. It will allow controlling fluid flow during long-term culture, whereby neotissue growth alters flow patterns, in order to provide shear stress profiles and magnitudes across the whole scaffold volume influencing, in turn, the neotissue growth. PMID:26758425

  5. Development of porous scaffolds for bone tissue engineering

    NASA Astrophysics Data System (ADS)

    Ramay, Hassna Rehman

    In bone tissue engineering, biodegradable scaffolds are used as a temporary biological and mechanical support for new tissue growth. A scaffold must have good biocompatibility, controllable degradation rate, and enough mechanical strength to support bone cell attachment, differentiation, and proliferation as it gradually degrades and finally is completely replaced by new bone tissues. Biological studies and clinical practices have established that a three-dimensional interconnected porous structure is necessary to allow cell attachment, proliferation, and differentiation, and to provide pathways for biofluids. However, the mechanical strength of a material generally decreases as increasing porosity. The conflicting interests between biological and mechanical requirements thus pose a challenge in developing porous scaffolds for load-bearing bone tissue engineering. Two types of ceramic scaffolds, (1) Hydroxaypatite and (2) Hydroxaypatite/tricalcium phosphate, are prepared in this study utilizing a novel technique that combines the gel casting and polymer sponge methods. This technique provides better control over material microstructure and can produce scaffolds with enhanced mechanical toughness and strength. The hydroxyapatite scaffolds prepared by this technique have an open, uniform and interconnected porous structure (˜porosity = 76%) with compressive modulus of 7 GPa, comparable to that of cortical bone, and compressive strength of 5 MPa, comparable to that of cancellous bone. The second type of ceramic scaffold is a biphasic nano composite with tricalcium phosphate as the main matrix reinforced with hydroxyapatite (HA) nano-fibers. The porous scaffold attained a compressive strength of 9.6 MPa (˜porosity = 73%), comparable to the high-end value of cancellous bone. The toughness of the scaffold increased from 1.00 to 1.72 kN/m (˜porosity = 73%), as the addition of HA nano-fibers increased up to 5 wt.%. Polymer scaffolds are prepared using a solid

  6. Modeling of porous scaffold deformation induced by medium perfusion.

    PubMed

    Podichetty, Jagdeep T; Madihally, Sundararajan V

    2014-05-01

    In this study, we tested the possibility of calculating permeability of porous scaffolds utilized in soft tissue engineering using pore size and shape. We validated the results using experimental measured pressure drop and simulations with the inclusion of structural deformation. We prepared Polycaprolactone (PCL) and Chitosan-Gelatin (CG) scaffolds by salt leaching and freeze drying technique, respectively. Micrographs were assessed for pore characteristics and mechanical properties. Porosity for both scaffolds was nearly same but the permeability varied 10-fold. Elastic moduli were 600 and 9 kPa for PCL and CG scaffolds, respectively, while Poisson's ratio was 0.3 for PCL scaffolds and ∼1.0 for CG scaffolds. A flow-through bioreactor accommodating a 10 cm diameter and 0.2 cm thick scaffold was used to determine the pressure-drop at various flow rates. Additionally, computational fluid dynamic (CFD) simulations were performed by coupling fluid flow, described by Brinkman equation, with structural mechanics using a dynamic mesh. The experimentally obtained pressure drop matched the simulation results of PCL scaffolds. Simulations were extended to a broad range of permeabilities (10(-10) m(2) to 10(-14) m(2) ), elastic moduli (10-100,000 kPa) and Poisson's ratio (0.1-0.49). The results showed significant deviation in pressure drop due to scaffold deformation compared to rigid scaffold at permeabilities near healthy tissues. Also, considering the scaffold as a nonrigid structure altered the shear stress profile. In summary, scaffold permeability can be calculated using scaffold pore characteristics and deformation could be predicted using CFD simulation. These relationships could potentially be used in monitoring tissue regeneration noninvasively via pressure drop. PMID:24259467

  7. ECM Inspired Coating of Embroidered 3D Scaffolds Enhances Calvaria Bone Regeneration

    PubMed Central

    Rentsch, C.; Rentsch, B.; Heinemann, S.; Bernhardt, R.; Bischoff, B.; Förster, Y.; Scharnweber, D.; Rammelt, S.

    2014-01-01

    Resorbable polymeric implants and surface coatings are an emerging technology to treat bone defects and increase bone formation. This approach is of special interest in anatomical regions like the calvaria since adults lose the capacity to heal large calvarial defects. The present study assesses the potential of extracellular matrix inspired, embroidered polycaprolactone-co-lactide (PCL) scaffolds for the treatment of 13 mm full thickness calvarial bone defects in rabbits. Moreover the influence of a collagen/chondroitin sulfate (coll I/cs) coating of PCL scaffolds was evaluated. Defect areas filled with autologous bone and empty defects served as reference. The healing process was monitored over 6 months by combining a novel ultrasonographic method, radiographic imaging, biomechanical testing, and histology. The PCL coll I/cs treated group reached 68% new bone volume compared to the autologous group (100%) and the biomechanical stability of the defect area was similar to that of the gold standard. Histological investigations revealed a significantly more homogenous bone distribution over the whole defect area in the PCL coll I/cs group compared to the noncoated group. The bioactive, coll I/cs coated, highly porous, 3-dimensional PCL scaffold acted as a guide rail for new skull bone formation along and into the implant. PMID:25013767

  8. Modeling Vascularized Bone Regeneration Within a Porous Biodegradable CaP Scaffold Loaded with Growth Factors

    PubMed Central

    Sun, X; Kang, Y; Bao, J; Zhang, Y; Yang, Y; Zhou, X

    2013-01-01

    Osteogenetic microenvironment is a complex constitution in which extracellular matrix (ECM) molecules, stem cells and growth factors each interact to direct the coordinate regulation of bone tissue development. Importantly, angiogenesis improvement and revascularization are critical for osteogenesis during bone tissue regeneration processes. In this study, we developed a three-dimensional (3D) multi-scale system model to study cell response to growth factors released from a 3D biodegradable porous calcium phosphate (CaP) scaffold. Our model reconstructed the 3D bone regeneration system and examined the effects of pore size and porosity on bone formation and angiogenesis. The results suggested that scaffold porosity played a more dominant role in affecting bone formation and angiogenesis compared with pore size, while the pore size could be controlled to tailor the growth factor release rate and release fraction. Furthermore, a combination of gradient VEGF with BMP2 and Wnt released from the multi-layer scaffold promoted angiogenesis and bone formation more readily than single growth factors. These results demonstrated that the developed model can be potentially applied to predict vascularized bone regeneration with specific scaffold and growth factors. PMID:23566802

  9. Tuning Cell Differentiation into a 3D Scaffold Presenting a Pore Shape Gradient for Osteochondral Regeneration.

    PubMed

    Di Luca, Andrea; Lorenzo-Moldero, Ivan; Mota, Carlos; Lepedda, Antonio; Auhl, Dietmar; Van Blitterswijk, Clemens; Moroni, Lorenzo

    2016-07-01

    Osteochondral regeneration remains nowadays a major problem since the outcome of current techniques is not satisfactory in terms of functional tissue formation and development. A possible solution is the combination of human mesenchymal stem cells (hMSCs) with additive manufacturing technologies to fabricate scaffolds with instructive properties. In this study, the differentiation of hMSCs within a scaffold presenting a gradient in pore shape is presented. The variation in pore shape is determined by varying the angle formed by the fibers of two consequent layers. The fiber deposition patterns are 0-90, which generate squared pores, 0-45, 0-30, and 0-15, that generate rhomboidal pores with an increasing major axis as the deposition angle decreases. Within the gradient construct, squared pores support a better chondrogenic differentiation whereas cells residing in the rhomboidal pores display a better osteogenic differentiation. When cultured under osteochondral conditions the trend in both osteogenic and chondrogenic markers is maintained. Engineering the pore shape, thus creating axial gradients in structural properties, seems to be an instructive strategy to fabricate functional 3D scaffolds that are able to influence hMSCs differentiation for osteochondral tissue regeneration. PMID:27109461

  10. A 3-D constitutive model for pressure-dependent phase transformation of porous shape memory alloys.

    PubMed

    Ashrafi, M J; Arghavani, J; Naghdabadi, R; Sohrabpour, S

    2015-02-01

    Porous shape memory alloys (SMAs) exhibit the interesting characteristics of porous metals together with shape memory effect and pseudo-elasticity of SMAs that make them appropriate for biomedical applications. In this paper, a 3-D phenomenological constitutive model for the pseudo-elastic behavior and shape memory effect of porous SMAs is developed within the framework of irreversible thermodynamics. Comparing to micromechanical and computational models, the proposed model is computationally cost effective and predicts the behavior of porous SMAs under proportional and non-proportional multiaxial loadings. Considering the pressure dependency of phase transformation in porous SMAs, proper internal variables, free energy and limit functions are introduced. With the aim of numerical implementation, time discretization and solution algorithm for the proposed model are also presented. Due to lack of enough experimental data on multiaxial loadings of porous SMAs, we employ a computational simulation method (CSM) together with available experimental data to validate the proposed constitutive model. The method is based on a 3-D finite element model of a representative volume element (RVE) with random pores pattern. Good agreement between the numerical predictions of the model and CSM results is observed for elastic and phase transformation behaviors in various thermomechanical loadings.

  11. Controlled implant/soft tissue interaction by nanoscale surface modifications of 3D porous titanium implants.

    PubMed

    Rieger, Elisabeth; Dupret-Bories, Agnès; Salou, Laetitia; Metz-Boutigue, Marie-Helene; Layrolle, Pierre; Debry, Christian; Lavalle, Philippe; Vrana, Nihal Engin

    2015-06-01

    Porous titanium implants are widely employed in the orthopaedics field to ensure good bone fixation. Recently, the use of porous titanium implants has also been investigated in artificial larynx development in a clinical setting. Such uses necessitate a better understanding of the interaction of soft tissues with porous titanium structures. Moreover, surface treatments of titanium have been generally evaluated in planar structures, while the porous titanium implants have complex 3 dimensional (3D) architectures. In this study, the determining factors for soft tissue integration of 3D porous titanium implants were investigated as a function of surface treatments via quantification of the interaction of serum proteins and cells with single titanium microbeads (300-500 μm in diameter). Samples were either acid etched or nanostructured by anodization. When the samples are used in 3D configuration (porous titanium discs of 2 mm thickness) in vivo (in subcutis of rats for 2 weeks), a better integration was observed for both anodized and acid etched samples compared to the non-treated implants. If the implants were also pre-treated with rat serum before implantation, the integration was further facilitated. In order to understand the underlying reasons for this effect, human fibroblast cell culture tests under several conditions (directly on beads, beads in suspension, beads encapsulated in gelatin hydrogels) were conducted to mimic the different interactions of cells with Ti implants in vivo. Physical characterization showed that surface treatments increased hydrophilicity, protein adsorption and roughness. Surface treatments also resulted in improved adsorption of serum albumin which in turn facilitated the adsorption of other proteins such as apolipoprotein as quantified by protein sequencing. The cellular response to the beads showed considerable difference with respect to the cell culture configuration. When the titanium microbeads were entrapped in cell

  12. Design control for clinical translation of 3D printed modular scaffolds.

    PubMed

    Hollister, Scott J; Flanagan, Colleen L; Zopf, David A; Morrison, Robert J; Nasser, Hassan; Patel, Janki J; Ebramzadeh, Edward; Sangiorgio, Sophia N; Wheeler, Matthew B; Green, Glenn E

    2015-03-01

    founded on 3D printing for developing tissue engineering therapies and (2) illustrate the design control process for modular implementation of two scaffold based tissue engineering therapies: airway reconstruction and bone tissue engineering based spine fusion. PMID:25666115

  13. Design Control for Clinical Translation of 3D Printed Modular Scaffolds

    PubMed Central

    Hollister, Scott J.; Flanagan, Colleen L.; Zopf, David A.; Morrison, Robert J.; Nasser, Hassan; Patel, Janki J.; Ebramzadeh, Edward; Sangiorgio, Sophia N.; Wheeler, Matthew B.; Green, Glenn E.

    2015-01-01

    founded on 3D printing for developing tissue engineering therapies and (2) illustrate the design control process for modular implementation of two scaffold based tissue engineering therapies: airway reconstruction and bone tissue engineering based spine fusion. PMID:25666115

  14. Design control for clinical translation of 3D printed modular scaffolds.

    PubMed

    Hollister, Scott J; Flanagan, Colleen L; Zopf, David A; Morrison, Robert J; Nasser, Hassan; Patel, Janki J; Ebramzadeh, Edward; Sangiorgio, Sophia N; Wheeler, Matthew B; Green, Glenn E

    2015-03-01

    founded on 3D printing for developing tissue engineering therapies and (2) illustrate the design control process for modular implementation of two scaffold based tissue engineering therapies: airway reconstruction and bone tissue engineering based spine fusion.

  15. Proton exchange membrane micro fuel cells on 3D porous silicon gas diffusion layers

    NASA Astrophysics Data System (ADS)

    Kouassi, S.; Gautier, G.; Thery, J.; Desplobain, S.; Borella, M.; Ventura, L.; Laurent, J.-Y.

    2012-10-01

    Since the 90's, porous silicon has been studied and implemented in many devices, especially in MEMS technology. In this article, we present a new approach to build miniaturized proton exchange membrane micro-fuel cells using porous silicon as a hydrogen diffusion layer. In particular, we propose an innovative process to build micro fuel cells from a “corrugated iron like” 3D structured porous silicon substrates. This structure is able to increase up to 40% the cell area keeping a constant footprint on the silicon wafer. We propose here a process route to perform electrochemically 3D porous gas diffusion layers and to deposit fuel cell active layers on such substrates. The prototype peak power performance was measured to be 90 mW cm-2 in a “breathing configuration” at room temperature. These performances are less than expected if we compare with a reference 2D micro fuel cell. Actually, the active layer deposition processes are not fully optimized but this prototype demonstrates the feasibility of these 3D devices.

  16. A 3D porous Ni-Cu alloy film for high-performance hydrazine electrooxidation

    NASA Astrophysics Data System (ADS)

    Sun, Ming; Lu, Zhiyi; Luo, Liang; Chang, Zheng; Sun, Xiaoming

    2016-01-01

    Structural design and catalyst screening are two most important factors for achieving exceptional electrocatalytic performance. Herein we demonstrate that constructing a three-dimensional (3D) porous Ni-Cu alloy film is greatly beneficial for improving the hydrazine oxidation reaction (HzOR) performance. A facile electrodeposition process is employed to synthesize a Ni-Cu alloy film with a 3D hierarchical porous structure. As an integrated electrode for HzOR, the Ni-Cu alloy film exhibits superior catalytic activity and stability to the Ni or Cu counterparts. The synthesis parameters are also systematically tuned for optimizing the HzOR performance. The excellent HzOR performance of the Ni-Cu alloy film is attributed to its high intrinsic activity, large electrochemical specific surface area, and 3D porous architecture which offers a ``superaerophobic'' surface to effectively remove the gas product in a small volume. It is believed that the Ni-Cu alloy film electrode has potential application in direct hydrazine fuel cells as well as other catalytic fields.Structural design and catalyst screening are two most important factors for achieving exceptional electrocatalytic performance. Herein we demonstrate that constructing a three-dimensional (3D) porous Ni-Cu alloy film is greatly beneficial for improving the hydrazine oxidation reaction (HzOR) performance. A facile electrodeposition process is employed to synthesize a Ni-Cu alloy film with a 3D hierarchical porous structure. As an integrated electrode for HzOR, the Ni-Cu alloy film exhibits superior catalytic activity and stability to the Ni or Cu counterparts. The synthesis parameters are also systematically tuned for optimizing the HzOR performance. The excellent HzOR performance of the Ni-Cu alloy film is attributed to its high intrinsic activity, large electrochemical specific surface area, and 3D porous architecture which offers a ``superaerophobic'' surface to effectively remove the gas product in a small

  17. High thick layer-by-layer 3D multiscale fibrous scaffolds for enhanced cell infiltration and it's potential in tissue engineering.

    PubMed

    Shalumon, K T; Chennazhi, K P; Nair, Shantikumar V; Jayakumar, R

    2013-12-01

    This work explains the fabrication and potential applicability of high thick three dimensional (3-D) electrospun multiscale fibrous scaffolds in tissue engineering by focusing on the possible fabrication techniques. Multiscale fibrous scaffold of poly(lactic acid) (PLA) was fabricated by combining nano and micro fibers in optimum concentrations. Finely chopped multiscale fibers were allowed to undergo compression, freeze-drying, resin embedding, cryo-grinding and layering techniques to make 3D scaffolds and the layer-by-layer method was found to be most suitable for 3-D scaffold fabrication. Cell studies in layered 3D scaffolds were performed using MG 63 cells and infiltration was observed using SEM and confocal microscope. Since the layered high thick 3D scaffold perfectly complies with the requirements, this could be proposed as one of the suitable methods for constructing 3D scaffolds for tissue engineering applications. PMID:24266265

  18. Functionally graded porous scaffolds made of Ti-based agglomerates.

    PubMed

    Nazari, Keivan A; Hilditch, Tim; Dargusch, Matthew S; Nouri, Alireza

    2016-10-01

    Mono- and double-layer porous scaffolds were successfully fabricated using ball-milled agglomerates of Ti and Ti-10Nb-3Mo alloy. For selectively controlling the level of porosity and pore size, the agglomerates were sieved into two different size fractions of 100-300μm and 300-500μm. Compressive mechanical properties were measured on a series of cylindrical sintered compacts with different ratios of solid core diameter to porous layer width. The graded porous scaffolds exhibited stress-strain curves typical for metallic foams with a defined plateau region after yielding. The compressive strengths and elastic moduli ranged from 300 to 700MPa and 14 to 55GPa, respectively, depending on the core diameter and the material used. The obtained properties make these materials suitable for load-bearing implant applications.

  19. Tissue engineering scaffold material of porous nanohydroxyapatite/polyamide 66.

    PubMed

    Xu, Qian; Lu, Hongyan; Zhang, Jingchao; Lu, Guoyu; Deng, Zhennan; Mo, Anchun

    2010-05-13

    The aim of the study was to investigate a porous nanohydroxyapatite/polyamide 66 (n-HA/PA66) scaffold material that was implanted into muscle and tibiae of 16 New Zealand white rabbits to evaluate the biocompatibility and osteogenesis and osteoinductivity of the materials in vivo. The samples were harvested at 2, 4, 12 and 26 weeks respectively, and subjected to histological analysis. At 2 weeks, the experiment showed that osteogenesis was detected in porous n-HA/PA66 composite and the density of new bone formation was similar to the surrounding host bone at 12 weeks. The study indicated that three-dimensional pore structures could facilitate cell adhesion, differentiation and proliferation, and help with fibrovascular and nerve colonization. In conclusion, porous n-HA/PA66 scaffold material could be a good candidate as a bone substitute material used in clinics due to its excellent histocompatibility, osteoconductivity and osteoinductivity.

  20. Controlled implant/soft tissue interaction by nanoscale surface modifications of 3D porous titanium implants

    NASA Astrophysics Data System (ADS)

    Rieger, Elisabeth; Dupret-Bories, Agnès; Salou, Laetitia; Metz-Boutigue, Marie-Helene; Layrolle, Pierre; Debry, Christian; Lavalle, Philippe; Engin Vrana, Nihal

    2015-05-01

    Porous titanium implants are widely employed in the orthopaedics field to ensure good bone fixation. Recently, the use of porous titanium implants has also been investigated in artificial larynx development in a clinical setting. Such uses necessitate a better understanding of the interaction of soft tissues with porous titanium structures. Moreover, surface treatments of titanium have been generally evaluated in planar structures, while the porous titanium implants have complex 3 dimensional (3D) architectures. In this study, the determining factors for soft tissue integration of 3D porous titanium implants were investigated as a function of surface treatments via quantification of the interaction of serum proteins and cells with single titanium microbeads (300-500 μm in diameter). Samples were either acid etched or nanostructured by anodization. When the samples are used in 3D configuration (porous titanium discs of 2 mm thickness) in vivo (in subcutis of rats for 2 weeks), a better integration was observed for both anodized and acid etched samples compared to the non-treated implants. If the implants were also pre-treated with rat serum before implantation, the integration was further facilitated. In order to understand the underlying reasons for this effect, human fibroblast cell culture tests under several conditions (directly on beads, beads in suspension, beads encapsulated in gelatin hydrogels) were conducted to mimic the different interactions of cells with Ti implants in vivo. Physical characterization showed that surface treatments increased hydrophilicity, protein adsorption and roughness. Surface treatments also resulted in improved adsorption of serum albumin which in turn facilitated the adsorption of other proteins such as apolipoprotein as quantified by protein sequencing. The cellular response to the beads showed considerable difference with respect to the cell culture configuration. When the titanium microbeads were entrapped in cell

  1. Tuning the Mechanical Properties of Poly(Ethylene Glycol) Microgel-Based Scaffolds to Increase 3D Schwann Cell Proliferation.

    PubMed

    Zhou, Wenda; Stukel, Jessica M; Cebull, Hannah L; Willits, Rebecca Kuntz

    2016-04-01

    2D in vitro studies have demonstrated that Schwann cells prefer scaffolds with mechanical modulus approximately 10× higher than the modulus preferred by nerves, limiting the ability of many scaffolds to promote both neuron extension and Schwann cell proliferation. Therefore, the goals of this work are to develop and characterize microgel-based scaffolds that are tuned over the stiffness range relevant to neural tissue engineering and investigate Schwann cell morphology, viability, and proliferation within 3D scaffolds. Using thiol-ene reaction, microgels with surface thiols are produced and crosslinked into hydrogels using a multiarm vinylsulfone (VS). By varying the concentration of VS, scaffold stiffness ranges from 0.13 to 0.76 kPa. Cell morphology in all groups demonstrates that cells are able to spread and interact with the scaffold through day 5. Although the viability in all groups is high, proliferation of Schwann cells within the scaffold of G* = 0.53 kPa is significantly higher than other groups. This result is ≈ 5× lower than previously reported optimal stiffnesses on 2D surfaces, demonstrating the need for correlation of 3D cell response to mechanical modulus. As proliferation is the first step in Schwann cell integration into peripheral nerve conduits, these scaffolds demonstrate that the stiffness is a critical parameter to optimizing the regenerative process.

  2. Efficient neuronal differentiation and maturation of human pluripotent stem cells encapsulated in 3D microfibrous scaffolds.

    PubMed

    Lu, Hong Fang; Lim, Sze-Xian; Leong, Meng Fatt; Narayanan, Karthikeyan; Toh, Rebecca P K; Gao, Shujun; Wan, Andrew C A

    2012-12-01

    Developing an efficient culture system for controlled human pluripotent stem cell (hPSC) differentiation into selected lineages is a major challenge in realizing stem cell-based clinical applications. Here, we report the use of chitin-alginate 3D microfibrous scaffolds, previously developed for hPSC propagation, to support efficient neuronal differentiation and maturation under chemically defined culture conditions. When treated with neural induction medium containing Noggin/retinoic acid, the encapsulated cells expressed much higher levels of neural progenitor markers SOX1 and PAX6 than those in other treatment conditions. Immunocytochemisty analysis confirmed that the majority of the differentiated cells were nestin-positive cells. Subsequently transferring the scaffolds to neuronal differentiation medium efficiently directed these encapsulated neural progenitors into mature neurons, as detected by RT-PCR and positive immunostaining for neuron markers βIII tubulin and MAP2. Furthermore, flow cytometry confirmed that >90% βIII tubulin-positive neurons was achieved for three independent iPSC and hESC lines, a differentiation efficiency much higher than previously reported. Implantation of these terminally differentiated neurons into SCID mice yielded successful neural grafts comprising MAP2 positive neurons, without tumorigenesis, suggesting a potential safe cell source for regenerative medicine. These results bring us one step closer toward realizing large-scale production of stem cell derivatives for clinical and translational applications. PMID:22998816

  3. Direct laser writing of 3D scaffolds for neural tissue engineering applications.

    PubMed

    Melissinaki, V; Gill, A A; Ortega, I; Vamvakaki, M; Ranella, A; Haycock, J W; Fotakis, C; Farsari, M; Claeyssens, F

    2011-12-01

    This study reports on the production of high-resolution 3D structures of polylactide-based materials via multi-photon polymerization and explores their use as neural tissue engineering scaffolds. To achieve this, a liquid polylactide resin was synthesized in house and rendered photocurable via attaching methacrylate groups to the hydroxyl end groups of the small molecular weight prepolymer. This resin cures easily under UV irradiation, using a mercury lamp, and under femtosecond IR irradiation. The results showed that the photocurable polylactide (PLA) resin can be readily structured via direct laser write (DLW) with a femtosecond Ti:sapphire laser and submicrometer structures can be produced. The maximum resolution achieved is 800 nm. Neuroblastoma cells were grown on thin films of the cured PLA material, and cell viability and proliferation assays revealed good biocompatibility of the material. Additionally, PC12 and NG108-15 neuroblastoma growth on bespoke scaffolds was studied in more detail to assess potential applications for neuronal implants of this material.

  4. Direct electrospinning of 3D auricle-shaped scaffolds for tissue engineering applications.

    PubMed

    Walser, Jochen; Stok, Kathryn S; Caversaccio, Marco D; Ferguson, Stephen J

    2016-05-12

    Thirty-two poly(ε)caprolactone (PCL) scaffolds have been produced by electrospinning directly into an auricle-shaped mould and seeded with articular chondrocytes harvested from bovine ankle joints. After seeding, the auricle shaped constructs were cultured in vitro and analysed at days 1, 7, 14 and 21 for regional differences in total DNA, glycosaminoglycan (GAG) and collagen (COL) content as well as the expression of aggrecan (AGG), collagen type I and type II (COL1/2) and matrix metalloproteinase 3 and 13 (MMP3/13). Stress-relaxation indentation testing was performed to investigate regional mechanical properties of the electrospun constructs. Electrospinning into a conductive mould yielded stable 3D constructs both initially and for the whole in vitro culture period, with an equilibrium modulus in the MPa range. Rapid cell proliferation and COL accumulation was observed until week 3. Quantitative real time PCR analysis showed an initial increase in AGG, no change in COL2, a persistent increase in COL1, and only a slight decrease initially for MMP3. Electrospinning of fibrous scaffolds directly into an auricle-shape represents a promising option for auricular tissue engineering, as it can reduce the steps needed to achieve an implantable structure.

  5. Electrodeposition of manganese oxide nanosheets on a continuous three-dimensional nickel porous scaffold for high performance electrochemical capacitors

    NASA Astrophysics Data System (ADS)

    Xiao, Junwu; Yang, Shengxiong; Wan, Lian; Xiao, Fei; Wang, Shuai

    2014-01-01

    It's desirable to design an ideal three-dimensional (3D) interpenetrating network as the current collector for providing efficient ion and electron transport. Herein, we report a facile method to fabricate a novel continuous 3D Ni porous nanoarchitecture via the reduction of Ni(OH)2 nanowall precursors. The as-formed continuous 3D Ni porous network as the conductive scaffold can support a highly electrolytic accessible surface area of redox active MnO2 nanosheets, and provide reliable electrical connections to the MnO2 layers. In comparison with the planar conducting substrates, this 3D scaffold not only can increase the mass loading of MnO2 active materials, but also facilitate the facile transport of electron and electrolyte ion. Thus, the 3D (MnO2/Ni) electrode exhibited higher specific capacitance (1169.6 F g-1 at 2 A g-1, closed to the theoretical value) and better long-term cyclability (only ∼5% loss after 1000 cycles) than that on the planar conducting substrate under the identical electrodeposition condition (611.6 F g-1 at 2 A g-1 and around 20% loss after 1000 cycles). These results suggest that such 3D Ni porous architecture is a promising current collector for high-performance electrochemical capacitor.

  6. 3D porous metal-organic framework exhibiting selective adsorption of water over organic solvents.

    PubMed

    Gu, Jin-Zhong; Lu, Wen-Guan; Jiang, Long; Zhou, Hong-Cai; Lu, Tong-Bu

    2007-07-23

    A 3D porous metal-organic framework (MOF) with 1D open channels has been constructed hydrothermally using Zn(II) and a rigid planar ligand IDC(3)- (imidazole-4,5-dicarboxylate). This MOF can adsorb water selectively over organic solvents and can be regenerated and reused. It also represents a rare example of a MOF with open channels that form/collapse reversibly upon hydration/dehydration.

  7. Direct writing of porous tissue scaffolds based on Vaseline-doped hydroxyapatite inks

    NASA Astrophysics Data System (ADS)

    Li, Ya-Yun; Li, Long-Tu; Li, Bo

    2015-05-01

    A novel type of 40 vol.% hydroxyapatite (HAp), Ca10(PO4)6(OH)2, suspension doped with Vaseline was developed, and porous three-dimensional (3D) scaffolds were fabricated by using a direct ink writing (DIW) method. The preparation of the HAp inks and the principles of the DIW technique were investigated. The microporosity of the scaffold wall increased after introducing the Vaseline, whereas macroporosity can be produced by varying the DIW technique. The micromorphology test results show that the samples sintered at 1150°C for 2 h formed ceramics with a set amount of pores, which benefit cell growth by providing more locations for cells to attach and proliferate. Under a microscope, the proliferations of human liver carcinoma cell line (HepG2) cells can be observed on the 3D HAp scaffolds. The DIW method has the advantages of a rapid process, ease of design and high precision control, potentially inspiring the design and application of biomaterials and scaffolds.

  8. Modeling the fluid-dynamics and oxygen consumption in a porous scaffold stimulated by cyclic squeeze pressure.

    PubMed

    Ferroni, Marco; Giusti, Serena; Nascimento, Diana; Silva, Ana; Boschetti, Federica; Ahluwalia, Arti

    2016-08-01

    The architecture and dynamic physical environment of tissues can be recreated in-vitro by combining 3D porous scaffolds and bioreactors able to apply controlled mechanical stimuli on cells. In such systems, the entity of the stimuli and the distribution of nutrients within the engineered construct depend on the micro-structure of the scaffolds. In this work, we present a new approach for optimizing computational fluid-dynamics (CFD) models for the investigation of fluid-induced forces generated by cyclic squeeze pressure within a porous construct, coupled with oxygen consumption of cardiomyocytes. A 2D axial symmetric macro-scaled model of a squeeze pressure bioreactor chamber was used as starting point for generating time dependent pressure profiles. Subsequently the fluid movement generated by the pressure fields was coupled with a complete 3D micro-scaled model of a porous protein cryogel. Oxygen transport and consumption inside the scaffold was evaluated considering a homogeneous distribution of cardiomyocytes throughout the structure, as confirmed by preliminary cell culture experiments. The results show that a 3D description of the system, coupling a porous geometry and time dependent pressure driven flow with fluid-structure-interaction provides an accurate and meaningful description of the microenvironment in terms of shear stress and oxygen distribution than simple stationary 2D models.

  9. Synthesis of various 3D porous gold-based alloy nanostructures with branched shapes.

    PubMed

    Swiatkowska-Warkocka, Zaneta; Pyatenko, Alexander; Koshizaki, Naoto; Kawaguchi, Kenji

    2016-12-01

    This paper presents a facile and flexible synthesis platform for various 3D porous gold-iron nanostructures based on selective laser heating of colloidal nanoparticles and selective acid treatment. The presented approach allows to create porous gold-based nanostructures with different morphologies. In addition, for the first time, our studies indicate that various nanoarchitectures (brain-like, flower-like, cage-like, or raspberry-like structures) can be obtained by varying the experimental conditions such as size of Au and Fe3O4 nanoparticles, solvent, laser fluence, and irradiation time. We believe that these porous structures will find immediate applications in catalysis and separations, where high surface area and magnetic properties are often simultaneously required. PMID:27565959

  10. Synthesis of various 3D porous gold-based alloy nanostructures with branched shapes.

    PubMed

    Swiatkowska-Warkocka, Zaneta; Pyatenko, Alexander; Koshizaki, Naoto; Kawaguchi, Kenji

    2016-12-01

    This paper presents a facile and flexible synthesis platform for various 3D porous gold-iron nanostructures based on selective laser heating of colloidal nanoparticles and selective acid treatment. The presented approach allows to create porous gold-based nanostructures with different morphologies. In addition, for the first time, our studies indicate that various nanoarchitectures (brain-like, flower-like, cage-like, or raspberry-like structures) can be obtained by varying the experimental conditions such as size of Au and Fe3O4 nanoparticles, solvent, laser fluence, and irradiation time. We believe that these porous structures will find immediate applications in catalysis and separations, where high surface area and magnetic properties are often simultaneously required.

  11. Vulnerability mapping of groundwater contamination based on 3D lithostratigraphical models of porous aquifers.

    PubMed

    Ducci, Daniela; Sellerino, Mariangela

    2013-03-01

    The aim of this paper is to apply a methodology in order to reconstruct a lithostratigraphic 3D model of an aquifer so as to define some parameters involved in the evaluation of the aquifer vulnerability to contamination of porous aquifers. The DRASTIC, SINTACS and AVI methods have been applied to an alluvial coastal aquifer of southern Italy. The stratigraphic reconstruction has been obtained by interpolating stratigraphic data from more than one borehole per 2 km. The lithostratigraphic reconstruction of a 3D model has been applied and used for three-dimensional or two-dimensional representations. In the first two methods, the layers of the vadose zone and the aquifer media have been evaluated not only by the interpolation of the single boreholes and piezometers, but also by the 3D model, assigning the scores of the parameters of each layer of the 3D model. The comparison between the maps constructed from the weighted values in each borehole and the maps deriving from the attribution of the values of each layer of the 3D model, highlights that the second representation avoids or minimizes the "bullseye" effect linked to the presence of boreholes with higher or lower values. The study has demonstrated that it is possible to integrate a 3D lithostratigraphic model of an aquifer in the assessment of the parameters involved in the evaluation of the aquifer vulnerability to contamination by Point Count System methods.

  12. The effect of 3D hydrogel scaffold modulus on osteoblast differentiation and mineralization revealed by combinatorial screening.

    PubMed

    Chatterjee, Kaushik; Lin-Gibson, Sheng; Wallace, William E; Parekh, Sapun H; Lee, Young Jong; Cicerone, Marcus T; Young, Marian F; Simon, Carl G

    2010-07-01

    Cells are known to sense and respond to the physical properties of their environment and those of tissue scaffolds. Optimizing these cell-material interactions is critical in tissue engineering. In this work, a simple and inexpensive combinatorial platform was developed to rapidly screen three-dimensional (3D) tissue scaffolds and was applied to screen the effect of scaffold properties for tissue engineering of bone. Differentiation of osteoblasts was examined in poly(ethylene glycol) hydrogel gradients spanning a 30-fold range in compressive modulus ( approximately 10 kPa to approximately 300 kPa). Results demonstrate that material properties (gel stiffness) of scaffolds can be leveraged to induce cell differentiation in 3D culture as an alternative to biochemical cues such as soluble supplements, immobilized biomolecules and vectors, which are often expensive, labile and potentially carcinogenic. Gel moduli of approximately 225 kPa and higher enhanced osteogenesis. Furthermore, it is proposed that material-induced cell differentiation can be modulated to engineer seamless tissue interfaces between mineralized bone tissue and softer tissues such as ligaments and tendons. This work presents a combinatorial method to screen biological response to 3D hydrogel scaffolds that more closely mimics the 3D environment experienced by cells in vivo.

  13. 3D-printed silicate porous bioceramics using a non-sacrificial preceramic polymer binder.

    PubMed

    Zocca, A; Elsayed, H; Bernardo, E; Gomes, C M; Lopez-Heredia, M A; Knabe, C; Colombo, P; Günster, J

    2015-05-22

    Silicate bioceramics possess an excellent bioactivity; however, shaping them into complex geometries is still challenging. Therefore, this paper aims to present a new strategy for the shaping of a bioglass-ceramic with controlled geometry and properties starting from a glass powder combined with a preceramic polymer, i.e. a silicon resin, and reactive fillers. The powder-based three-dimensional (3D)-printing of wollastonite (CaSiO3)-based silicate bioceramic parts was demonstrated in this work. The resin plays a dual role, as it not only acts as a non-sacrificial binder for the filler powders in the printing process but it also reacts with the fillers to generate the desired bioceramic phases. The mechanical and physical properties, i.e. ball-on-three-balls test, density, porosity and morphology, were evaluated in 3D-printed discs. These samples possessed a total porosity around 64 vol% and a biaxial flexural strength around 6 MPa. The raw materials used in this work also enabled the 3D-printing of scaffolds possessing a designed multi-scale porosity, suitable bioceramic phase assemblage and a compressive strength of 1 MPa (for cylindrical scaffolds with total porosity ~80 vol%). Solubility in TRIS/HCl and in vitro assays, i.e. viability, cytotoxicity and apoptosis assays, were also performed. In vitro tests indicated good cell viability and no cytotoxicity effect on the cells.

  14. 3D-printed silicate porous bioceramics using a non-sacrificial preceramic polymer binder.

    PubMed

    Zocca, A; Elsayed, H; Bernardo, E; Gomes, C M; Lopez-Heredia, M A; Knabe, C; Colombo, P; Günster, J

    2015-06-01

    Silicate bioceramics possess an excellent bioactivity; however, shaping them into complex geometries is still challenging. Therefore, this paper aims to present a new strategy for the shaping of a bioglass-ceramic with controlled geometry and properties starting from a glass powder combined with a preceramic polymer, i.e. a silicon resin, and reactive fillers. The powder-based three-dimensional (3D)-printing of wollastonite (CaSiO3)-based silicate bioceramic parts was demonstrated in this work. The resin plays a dual role, as it not only acts as a non-sacrificial binder for the filler powders in the printing process but it also reacts with the fillers to generate the desired bioceramic phases. The mechanical and physical properties, i.e. ball-on-three-balls test, density, porosity and morphology, were evaluated in 3D-printed discs. These samples possessed a total porosity around 64 vol% and a biaxial flexural strength around 6 MPa. The raw materials used in this work also enabled the 3D-printing of scaffolds possessing a designed multi-scale porosity, suitable bioceramic phase assemblage and a compressive strength of 1 MPa (for cylindrical scaffolds with total porosity ~80 vol%). Solubility in TRIS/HCl and in vitro assays, i.e. viability, cytotoxicity and apoptosis assays, were also performed. In vitro tests indicated good cell viability and no cytotoxicity effect on the cells. PMID:26000907

  15. Electrochemical fabrication of 2D and 3D nickel nanowires using porous anodic alumina templates

    NASA Astrophysics Data System (ADS)

    Mebed, A. M.; Abd-Elnaiem, Alaa M.; Al-Hosiny, Najm M.

    2016-06-01

    Mechanically stable nickel (Ni) nanowires array and nanowires network were synthesized by pulse electrochemical deposition using 2D and 3D porous anodic alumina (PAA) templates. The structures and morphologies of as-prepared films were characterized by X-ray diffraction and scanning electron microscopy, respectively. The grown Ni nanowire using 3D PAA revealed more strength and larger surface area than has grown Ni use 2D PAA template. The prepared nanowires have a face-centered cubic crystal structure with average grain size 15 nm, and the preferred orientation of the nucleation of the nanowires is (111). The diameter of the nanowires is about 50-70 nm with length 3 µm. The resulting 3D Ni nanowire lattice, which provides enhanced mechanical stability and an increased surface area, benefits energy storage and many other applications which utilize the large surface area.

  16. Combination of thermal extrusion printing and ultrafast laser fabrication for the manufacturing of 3D composite scaffolds

    NASA Astrophysics Data System (ADS)

    Balčiūnas, Evaldas; Lukoševičius, Laurynas; Mackevičiūtė, Dovilė; Rekštytė, Sima; Rutkūnas, Vygandas; Paipulas, Domas; Stankevičiūtė, Karolina; Baltriukienė, Daiva; Bukelskienė, Virginija; Piskarskas, Algis P.; Malinauskas, Mangirdas

    2014-03-01

    We present a novel approach to manufacturing 3D microstructured composite scaffolds for tissue engineering applications. A thermal extrusion 3D printer - a simple, low-cost tabletop device enabling rapid materialization of CAD models in plastics - was used to produce cm-scale microporous scaffolds out of polylactic acid (PLA). The fabricated objects were subsequently immersed in a photosensitive monomer solution and direct laser writing technique (DLW) was used to refine its inner structure by fabricating a fine mesh inside the previously produced scaffold. In addition, a composite material structure out of four different materials fabricated via DLW is presented. This technique, empowered by ultrafast lasers allows 3D structuring with high spatial resolution in a great variety of photosensitive materials. A composite scaffold made of distinct materials and periodicities is acquired after the development process used to wash out non-linked monomers. Another way to modify the 3D printed PLA surfaces was also demonstrated - ablation with femtosecond laser beam. Structure geometry on macro- to micro- scales could be finely tuned by combining these fabrication techniques. Such artificial 3D substrates could be used for cell growth or as biocompatible-biodegradable implants. To our best knowledge, this is the first experimental demonstration showing the creation of composite 3D scaffolds using convenient 3D printing combined with DLW. This combination of distinct material processing techniques enables rapid fabrication of diverse functional micro-featured and integrated devices. Hopefully, the proposed approach will find numerous applications in the field of tissue engineering, as well as in microelectromechanical systems, microfluidics, microoptics and others.

  17. Hierarchical bioceramic scaffolds with 3D-plotted macropores and mussel-inspired surface nanolayers for stimulating osteogenesis

    NASA Astrophysics Data System (ADS)

    Xu, Mengchi; Zhai, Dong; Xia, Lunguo; Li, Hong; Chen, Shiyi; Fang, Bing; Chang, Jiang; Wu, Chengtie

    2016-07-01

    The hierarchical structure of biomaterials plays an important role in the process of tissue reconstruction and regeneration. 3D-plotted scaffolds have been widely used for bone tissue engineering due to their controlled macropore structure and mechanical properties. However, the lack of micro- or nano-structures on the strut surface of 3D-plotted scaffolds, especially for bioceramic scaffolds, limits their biological activity. Inspired by the adhesive versatility of mussels and the active ion-chelating capacity of polydopamine, we set out to prepare a hierarchical bioceramic scaffold with controlled macropores and mussel-inspired surface nanolayers by combining the 3D-plotting technique with the polydopamine/apatite hybrid strategy in order to synergistically accelerate the osteogenesis and angiogenesis. β-Tricalcium phosphate (TCP) scaffolds were firstly 3D-plotted and then treated in dopamine-Tris/HCl and dopamine-SBF solutions to obtain TCP-DOPA-Tris and TCP-DOPA-SBF scaffolds, respectively. It was found that polydopamine/apatite hybrid nanolayers were formed on the surface of both TCP-DOPA-Tris and TCP-DOPA-SBF scaffolds and TCP-DOPA-SBF scaffolds induced apatite mineralization for the second time during the cell culture. As compared to TCP scaffolds, both TCP-DOPA-Tris and TCP-DOPA-SBF scaffolds significantly promoted the osteogenesis of bone marrow stromal cells (BMSCs) as well as the angiogenesis of human umbilical vein endothelial cells (HUVECs), and the TCP-DOPA-SBF group presented the highest in vitro osteogenic/angiogenic activity among the three groups. Furthermore, both TCP-DOPA-Tris and TCP-DOPA-SBF scaffolds significantly improved the formation of new bone in vivo as compared to TCP scaffolds without a nanostructured surface. Our results suggest that the utilization of a mussel-inspired Ca, P-chelated polydopamine nanolayer on 3D-plotted bioceramic scaffolds is a viable and effective strategy to construct a hierarchical structure for synergistically

  18. Hierarchical bioceramic scaffolds with 3D-plotted macropores and mussel-inspired surface nanolayers for stimulating osteogenesis

    NASA Astrophysics Data System (ADS)

    Xu, Mengchi; Zhai, Dong; Xia, Lunguo; Li, Hong; Chen, Shiyi; Fang, Bing; Chang, Jiang; Wu, Chengtie

    2016-07-01

    The hierarchical structure of biomaterials plays an important role in the process of tissue reconstruction and regeneration. 3D-plotted scaffolds have been widely used for bone tissue engineering due to their controlled macropore structure and mechanical properties. However, the lack of micro- or nano-structures on the strut surface of 3D-plotted scaffolds, especially for bioceramic scaffolds, limits their biological activity. Inspired by the adhesive versatility of mussels and the active ion-chelating capacity of polydopamine, we set out to prepare a hierarchical bioceramic scaffold with controlled macropores and mussel-inspired surface nanolayers by combining the 3D-plotting technique with the polydopamine/apatite hybrid strategy in order to synergistically accelerate the osteogenesis and angiogenesis. β-Tricalcium phosphate (TCP) scaffolds were firstly 3D-plotted and then treated in dopamine-Tris/HCl and dopamine-SBF solutions to obtain TCP-DOPA-Tris and TCP-DOPA-SBF scaffolds, respectively. It was found that polydopamine/apatite hybrid nanolayers were formed on the surface of both TCP-DOPA-Tris and TCP-DOPA-SBF scaffolds and TCP-DOPA-SBF scaffolds induced apatite mineralization for the second time during the cell culture. As compared to TCP scaffolds, both TCP-DOPA-Tris and TCP-DOPA-SBF scaffolds significantly promoted the osteogenesis of bone marrow stromal cells (BMSCs) as well as the angiogenesis of human umbilical vein endothelial cells (HUVECs), and the TCP-DOPA-SBF group presented the highest in vitro osteogenic/angiogenic activity among the three groups. Furthermore, both TCP-DOPA-Tris and TCP-DOPA-SBF scaffolds significantly improved the formation of new bone in vivo as compared to TCP scaffolds without a nanostructured surface. Our results suggest that the utilization of a mussel-inspired Ca, P-chelated polydopamine nanolayer on 3D-plotted bioceramic scaffolds is a viable and effective strategy to construct a hierarchical structure for synergistically

  19. A 3D similarity method for scaffold hopping from known drugs or natural ligands to new chemotypes.

    PubMed

    Jenkins, Jeremy L; Glick, Meir; Davies, John W

    2004-12-01

    A primary goal of 3D similarity searching is to find compounds with similar bioactivity to a reference ligand but with different chemotypes, i.e., "scaffold hopping". However, an adequate description of chemical structures in 3D conformational space is difficult due to the high-dimensionality of the problem. We present an automated method that simplifies flexible 3D chemical descriptions in which clustering techniques traditionally used in data mining are exploited to create "fuzzy" molecular representations called FEPOPS (feature point pharmacophores). The representations can be used for flexible 3D similarity searching given one or more active compounds without a priori knowledge of bioactive conformations or pharmacophores. We demonstrate that similarity searching with FEPOPS significantly enriches for actives taken from in-house high-throughput screening datasets and from MDDR activity classes COX-2, 5-HT3A, and HIV-RT, while also scaffold or ring-system hopping to new chemical frameworks. Further, inhibitors of target proteins (dopamine 2 and retinoic acid receptor) are recalled by FEPOPS by scaffold hopping from their associated endogenous ligands (dopamine and retinoic acid). Importantly, the method excels in comparison to commonly used 2D similarity methods (DAYLIGHT, MACCS, Pipeline Pilot fingerprints) and a commercial 3D method (Pharmacophore Distance Triplets) at finding novel scaffold classes given a single query molecule.

  20. Injectable and porous PLGA microspheres that form highly porous scaffolds at body temperature

    PubMed Central

    Qutachi, Omar; Vetsch, Jolanda R.; Gill, Daniel; Cox, Helen; Scurr, David J.; Hofmann, Sandra; Müller, Ralph; Quirk, Robin A.; Shakesheff, Kevin M.; Rahman, Cheryl V.

    2014-01-01

    Injectable scaffolds are of interest in the field of regenerative medicine because of their minimally invasive mode of delivery. For tissue repair applications, it is essential that such scaffolds have the mechanical properties, porosity and pore diameter to support the formation of new tissue. In the current study, porous poly(dl-lactic acid-co-glycolic acid) (PLGA) microspheres were fabricated with an average size of 84 ± 24 μm for use as injectable cell carriers. Treatment with ethanolic sodium hydroxide for 2 min was observed to increase surface porosity without causing the microsphere structure to disintegrate. This surface treatment also enabled the microspheres to fuse together at 37 °C to form scaffold structures. The average compressive strength of the scaffolds after 24 h at 37 °C was 0.9 ± 0.1 MPa, and the average Young’s modulus was 9.4 ± 1.2 MPa. Scaffold porosity levels were 81.6% on average, with a mean pore diameter of 54 ± 38 μm. This study demonstrates a method for fabricating porous PLGA microspheres that form solid porous scaffolds at body temperature, creating an injectable system capable of supporting NIH-3T3 cell attachment and proliferation in vitro. PMID:25152354

  1. Characterization of mechanical and biological properties of 3-D scaffolds reinforced with zinc oxide for bone tissue engineering.

    PubMed

    Feng, Pei; Wei, Pingpin; Shuai, Cijun; Peng, Shuping

    2014-01-01

    A scaffold for bone tissue engineering should have highly interconnected porous structure, appropriate mechanical and biological properties. In this work, we fabricated well-interconnected porous β-tricalcium phosphate (β-TCP) scaffolds via selective laser sintering (SLS). We found that the mechanical and biological properties of the scaffolds were improved by doping of zinc oxide (ZnO). Our data showed that the fracture toughness increased from 1.09 to 1.40 MPam(1/2), and the compressive strength increased from 3.01 to 17.89 MPa when the content of ZnO increased from 0 to 2.5 wt%. It is hypothesized that the increase of ZnO would lead to a reduction in grain size and an increase in density of the strut. However, the fracture toughness and compressive strength decreased with further increasing of ZnO content, which may be due to the sharp increase in grain size. The biocompatibility of the scaffolds was investigated by analyzing the adhesion and the morphology of human osteoblast-like MG-63 cells cultured on the surfaces of the scaffolds. The scaffolds exhibited better and better ability to support cell attachment and proliferation when the content of ZnO increased from 0 to 2.5 wt%. Moreover, a bone like apatite layer formed on the surfaces of the scaffolds after incubation in simulated body fluid (SBF), indicating an ability of osteoinduction and osteoconduction. In summary, interconnected porous β-TCP scaffolds doped with ZnO were successfully fabricated and revealed good mechanical and biological properties, which may be used for bone repair and replacement potentially.

  2. Characterization of Mechanical and Biological Properties of 3-D Scaffolds Reinforced with Zinc Oxide for Bone Tissue Engineering

    PubMed Central

    Shuai, Cijun; Peng, Shuping

    2014-01-01

    A scaffold for bone tissue engineering should have highly interconnected porous structure, appropriate mechanical and biological properties. In this work, we fabricated well-interconnected porous β-tricalcium phosphate (β-TCP) scaffolds via selective laser sintering (SLS). We found that the mechanical and biological properties of the scaffolds were improved by doping of zinc oxide (ZnO). Our data showed that the fracture toughness increased from 1.09 to 1.40 MPam1/2, and the compressive strength increased from 3.01 to 17.89 MPa when the content of ZnO increased from 0 to 2.5 wt%. It is hypothesized that the increase of ZnO would lead to a reduction in grain size and an increase in density of the strut. However, the fracture toughness and compressive strength decreased with further increasing of ZnO content, which may be due to the sharp increase in grain size. The biocompatibility of the scaffolds was investigated by analyzing the adhesion and the morphology of human osteoblast-like MG-63 cells cultured on the surfaces of the scaffolds. The scaffolds exhibited better and better ability to support cell attachment and proliferation when the content of ZnO increased from 0 to 2.5 wt%. Moreover, a bone like apatite layer formed on the surfaces of the scaffolds after incubation in simulated body fluid (SBF), indicating an ability of osteoinduction and osteoconduction. In summary, interconnected porous β-TCP scaffolds doped with ZnO were successfully fabricated and revealed good mechanical and biological properties, which may be used for bone repair and replacement potentially. PMID:24498185

  3. The fabrication of double layer tubular vascular tissue engineering scaffold via coaxial electrospinning and its 3D cell coculture.

    PubMed

    Ye, Lin; Cao, Jie; Chen, Lamei; Geng, Xue; Zhang, Ai-Ying; Guo, Lian-Rui; Gu, Yong-Quan; Feng, Zeng-Guo

    2015-12-01

    A continuous electrospinning technique was applied to fabricate double layer tubular tissue engineering vascular graft (TEVG) scaffold. The luminal layer was made from poly(ɛ-caprolac-tone)(PCL) ultrafine fibers via common single axial electrospinning followed by the outer layer of core-shell structured nanofibers via coaxial electrospinning. For preparing the outer layernano-fibers, the PCL was electrospun into the shell and both bovine serum albumin (BSA) and tetrapeptide val-gal-pro-gly (VAPG) were encapsulated into the core. The core-shell structure in the outer layer fibers was observed by transmission electron microscope (TEM). The in vitro release tests exhibited the sustainable release behavior of BSA and VAPG so that they provided a better cell growth environment in the interior of tubular scaffold wall. The in vitro culture of smooth muscle cells (SMCs) demonstrated their potential to penetrate into the scaffold wall for the 3D cell culture. Subsequently, 3D cell coculture was conducted. First, SMCs were seeded on the luminal surface of the scaffold and cultured for 5 days, and then endothelial cells (ECs) were also seeded on the luminal surface and cocultured with SMCs for another 2 days. After stained with antibodies, 3D cell distribution on the scaffold was revealed by confocal laser scanning microscopy (CLSM) where ECs were mainly located on the luminal surface whereas SMCs penetrated into the surface and distributed inside the scaffold wall. This double layer tubular scaffold with 3D cell distribution showed the promise to develop it into a novel TEVG for clinical trials in the near future.

  4. Development of bioartificial myocardium by electrostimulation of 3D collagen scaffolds seeded with stem cells

    PubMed Central

    Haneef, Kanwal; Lila, Nermine; Benadda, Samira; Legrand, Fabien; Carpentier, Alain; Chachques, Juan C.

    2012-01-01

    Electrostimulation (ES) can be defined as a safe physical method to induce stem cell differentiation. The aim of this study is to evaluate the effectiveness of ES on bone marrow mesenchymal stem cells (BMSCs) seeded in collagen scaffolds in terms of proliferation and differentiation into cardiomyocytes. BMSCs were isolated from Wistar rats and seeded into 3D collagen type 1 templates measuring 25 × 25 × 6 mm. Bipolar in vitro ES was performed during 21 days. Electrical impedance and cell proliferation were measured. Expression of cardiac markers was assessed by immunocytochemistry. Viscoelasticity of collagen matrix was evaluated. Electrical impedance assessments showed a low resistance of 234±41 Ohms which indicates good electrical conductivity of collagen matrix. Cell proliferation at 570 nm as significantly increased in ES groups after seven day (ES 0.129±0.03 vs non-stimulated control matrix 0.06±0.01, P=0.002) and after 21 days, (ES 0.22±0.04 vs control 0.13±0.01, P=0.01). Immunocytoche mistry of BMSCs after 21 days ES showed positive staining of cardiac markers, troponin I, connexin 43, sarcomeric alpha-actinin, slow myosin, fast myosin and desmin. Staining for BMSCs marker CD29 after 21 days was negative. Electrostimulation of cell-seeded collagen matrix changed stem cell morphology and biochemical characteristics, increasing the expression of cardiac markers. Thus, MSC-derived differentiated cells by electrostimulation grafted in biological scaffolds might result in a convenient tissue engineering source for myocardial diseases. PMID:23185681

  5. Development of bioartificial myocardium by electrostimulation of 3D collagen scaffolds seeded with stem cells.

    PubMed

    Haneef, Kanwal; Lila, Nermine; Benadda, Samira; Legrand, Fabien; Carpentier, Alain; Chachques, Juan C

    2012-06-01

    Electrostimulation (ES) can be defined as a safe physical method to induce stem cell differentiation. The aim of this study is to evaluate the effectiveness of ES on bone marrow mesenchymal stem cells (BMSCs) seeded in collagen scaffolds in terms of proliferation and differentiation into cardiomyocytes. BMSCs were isolated from Wistar rats and seeded into 3D collagen type 1 templates measuring 25 × 25 × 6 mm. Bipolar in vitro ES was performed during 21 days. Electrical impedance and cell proliferation were measured. Expression of cardiac markers was assessed by immunocytochemistry. Viscoelasticity of collagen matrix was evaluated. Electrical impedance assessments showed a low resistance of 234±41 Ohms which indicates good electrical conductivity of collagen matrix. Cell proliferation at 570 nm as significantly increased in ES groups after seven day (ES 0.129±0.03 vs non-stimulated control matrix 0.06±0.01, P=0.002) and after 21 days, (ES 0.22±0.04 vs control 0.13±0.01, P=0.01). Immunocytoche mistry of BMSCs after 21 days ES showed positive staining of cardiac markers, troponin I, connexin 43, sarcomeric alpha-actinin, slow myosin, fast myosin and desmin. Staining for BMSCs marker CD29 after 21 days was negative. Electrostimulation of cell-seeded collagen matrix changed stem cell morphology and biochemical characteristics, increasing the expression of cardiac markers. Thus, MSC-derived differentiated cells by electrostimulation grafted in biological scaffolds might result in a convenient tissue engineering source for myocardial diseases.

  6. Adhesion and growth of human bone marrow mesenchymal stem cells on precise-geometry 3D organic-inorganic composite scaffolds for bone repair.

    PubMed

    Chatzinikolaidou, Maria; Rekstyte, Sima; Danilevicius, Paulius; Pontikoglou, Charalampos; Papadaki, Helen; Farsari, Maria; Vamvakaki, Maria

    2015-03-01

    Engineering biomaterial scaffolds that promote attachment and growth of mesenchymal stem cells in three dimensions is a crucial parameter for successful bone tissue engineering. Towards this direction, a lot of research effort has focused recently into the development of three-dimensional porous scaffolds, aiming to elicit positive cellular behavior. However, the fabrication of three-dimensional tissue scaffolds with a precise geometry and complex micro- and nano-features, supporting cell in-growth remains a challenge. In this study we report on a positive cellular response of human bone marrow-derived (BM) mesenchymal stem cells (MSCs) onto hybrid material scaffolds consisting of methacryloxypropyl trimethoxysilane, zirconium propoxide, and 2-(dimethylamino)ethyl methacrylate (DMAEMA). First, we use Direct fs Laser Writing, a 3D scaffolding technology to fabricate the complex structures. Subsequently, we investigate the morphology, viability and proliferation of BM-MSCs onto the hybrid scaffolds and examine the cellular response from different donors. Finally, we explore the effect of the materials' chemical composition on cell proliferation, employing three different material surfaces: (i) a hybrid consisting of methacryloxypropyl trimethoxysilane, zirconium propoxide and 50mol% DMAEMA, (ii) a hybrid material comprising methacryloxypropyl trimethoxysilane and zirconium propoxide, and (iii) a purely organic polyDMAEMA. Our results show a strong adhesion of BM-MSCs onto the hybrid material containing 50% DMAEMA from the first 2h after seeding, and up to several days, and a proliferation increase after 14 and 21days, similar to the polystyrene control, independent of cell donor. These findings support the potential use of our proposed cell-material combination in bone tissue engineering.

  7. High nitrogen-containing cotton derived 3D porous carbon frameworks for high-performance supercapacitors

    PubMed Central

    Fan, Li-Zhen; Chen, Tian-Tian; Song, Wei-Li; Li, Xiaogang; Zhang, Shichao

    2015-01-01

    Supercapacitors fabricated by 3D porous carbon frameworks, such as graphene- and carbon nanotube (CNT)-based aerogels, have been highly attractive due to their various advantages. However, their high cost along with insufficient yield has inhibited their large-scale applications. Here we have demonstrated a facile and easily scalable approach for large-scale preparing novel 3D nitrogen-containing porous carbon frameworks using ultralow-cost commercial cotton. Electrochemical performance suggests that the optimal nitrogen-containing cotton-derived carbon frameworks with a high nitrogen content (12.1 mol%) along with low surface area 285 m2 g−1 present high specific capacities of the 308 and 200 F g−1 in KOH electrolyte at current densities of 0.1 and 10 A g−1, respectively, with very limited capacitance loss upon 10,000 cycles in both aqueous and gel electrolytes. Moreover, the electrode exhibits the highest capacitance up to 220 F g−1 at 0.1 A g−1 and excellent flexibility (with negligible capacitance loss under different bending angles) in the polyvinyl alcohol/KOH gel electrolyte. The observed excellent performance competes well with that found in the electrodes of similar 3D frameworks formed by graphene or CNTs. Therefore, the ultralow-cost and simply strategy here demonstrates great potential for scalable producing high-performance carbon-based supercapacitors in the industry. PMID:26472144

  8. High nitrogen-containing cotton derived 3D porous carbon frameworks for high-performance supercapacitors

    NASA Astrophysics Data System (ADS)

    Fan, Li-Zhen; Chen, Tian-Tian; Song, Wei-Li; Li, Xiaogang; Zhang, Shichao

    2015-10-01

    Supercapacitors fabricated by 3D porous carbon frameworks, such as graphene- and carbon nanotube (CNT)-based aerogels, have been highly attractive due to their various advantages. However, their high cost along with insufficient yield has inhibited their large-scale applications. Here we have demonstrated a facile and easily scalable approach for large-scale preparing novel 3D nitrogen-containing porous carbon frameworks using ultralow-cost commercial cotton. Electrochemical performance suggests that the optimal nitrogen-containing cotton-derived carbon frameworks with a high nitrogen content (12.1 mol%) along with low surface area 285 m2 g-1 present high specific capacities of the 308 and 200 F g-1 in KOH electrolyte at current densities of 0.1 and 10 A g-1, respectively, with very limited capacitance loss upon 10,000 cycles in both aqueous and gel electrolytes. Moreover, the electrode exhibits the highest capacitance up to 220 F g-1 at 0.1 A g-1 and excellent flexibility (with negligible capacitance loss under different bending angles) in the polyvinyl alcohol/KOH gel electrolyte. The observed excellent performance competes well with that found in the electrodes of similar 3D frameworks formed by graphene or CNTs. Therefore, the ultralow-cost and simply strategy here demonstrates great potential for scalable producing high-performance carbon-based supercapacitors in the industry.

  9. Engineering anatomically shaped vascularized bone grafts with hASCs and 3D-printed PCL scaffolds.

    PubMed

    Temple, Joshua P; Hutton, Daphne L; Hung, Ben P; Huri, Pinar Yilgor; Cook, Colin A; Kondragunta, Renu; Jia, Xiaofeng; Grayson, Warren L

    2014-12-01

    The treatment of large craniomaxillofacial bone defects is clinically challenging due to the limited availability of transplantable autologous bone grafts and the complex geometry of the bones. The ability to regenerate new bone tissues that faithfully replicate the anatomy would revolutionize treatment options. Advances in the field of bone tissue engineering over the past few decades offer promising new treatment alternatives using biocompatible scaffold materials and autologous cells. This approach combined with recent advances in three-dimensional (3D) printing technologies may soon allow the generation of large, bioartificial bone grafts with custom, patient-specific architecture. In this study, we use a custom-built 3D printer to develop anatomically shaped polycaprolactone (PCL) scaffolds with varying internal porosities. These scaffolds are assessed for their ability to support induction of human adipose-derived stem cells (hASCs) to form vasculature and bone, two essential components of functional bone tissue. The development of functional tissues is assessed in vitro and in vivo. Finally, we demonstrate the ability to print large mandibular and maxillary bone scaffolds that replicate fine details extracted from patient's computed tomography scans. The findings of this study illustrate the capabilities and potential of 3D printed scaffolds to be used for engineering autologous, anatomically shaped, vascularized bone grafts.

  10. Fabrication of scalable tissue engineering scaffolds with dual-pore microarchitecture by combining 3D printing and particle leaching.

    PubMed

    Mohanty, Soumyaranjan; Sanger, Kuldeep; Heiskanen, Arto; Trifol, Jon; Szabo, Peter; Dufva, Marin; Emnéus, Jenny; Wolff, Anders

    2016-04-01

    Limitations in controlling scaffold architecture using traditional fabrication techniques are a problem when constructing engineered tissues/organs. Recently, integration of two pore architectures to generate dual-pore scaffolds with tailored physical properties has attracted wide attention in tissue engineering community. Such scaffolds features primary structured pores which can efficiently enhance nutrient/oxygen supply to the surrounding, in combination with secondary random pores, which give high surface area for cell adhesion and proliferation. Here, we present a new technique to fabricate dual-pore scaffolds for various tissue engineering applications where 3D printing of poly(vinyl alcohol) (PVA) mould is combined with salt leaching process. In this technique the sacrificial PVA mould, determining the structured pore architecture, was filled with salt crystals to define the random pore regions of the scaffold. After crosslinking the casted polymer the combined PVA-salt mould was dissolved in water. The technique has advantages over previously reported ones, such as automated assembly of the sacrificial mould, and precise control over pore architecture/dimensions by 3D printing parameters. In this study, polydimethylsiloxane and biodegradable poly(ϵ-caprolactone) were used for fabrication. However, we show that this technique is also suitable for other biocompatible/biodegradable polymers. Various physical and mechanical properties of the dual-pore scaffolds were compared with control scaffolds with either only structured or only random pores, fabricated using previously reported methods. The fabricated dual-pore scaffolds supported high cell density, due to the random pores, in combination with uniform cell distribution throughout the scaffold, and higher cell proliferation and viability due to efficient nutrient/oxygen transport through the structured pores. In conclusion, the described fabrication technique is rapid, inexpensive, scalable, and compatible

  11. Fabrication of scalable tissue engineering scaffolds with dual-pore microarchitecture by combining 3D printing and particle leaching.

    PubMed

    Mohanty, Soumyaranjan; Sanger, Kuldeep; Heiskanen, Arto; Trifol, Jon; Szabo, Peter; Dufva, Marin; Emnéus, Jenny; Wolff, Anders

    2016-04-01

    Limitations in controlling scaffold architecture using traditional fabrication techniques are a problem when constructing engineered tissues/organs. Recently, integration of two pore architectures to generate dual-pore scaffolds with tailored physical properties has attracted wide attention in tissue engineering community. Such scaffolds features primary structured pores which can efficiently enhance nutrient/oxygen supply to the surrounding, in combination with secondary random pores, which give high surface area for cell adhesion and proliferation. Here, we present a new technique to fabricate dual-pore scaffolds for various tissue engineering applications where 3D printing of poly(vinyl alcohol) (PVA) mould is combined with salt leaching process. In this technique the sacrificial PVA mould, determining the structured pore architecture, was filled with salt crystals to define the random pore regions of the scaffold. After crosslinking the casted polymer the combined PVA-salt mould was dissolved in water. The technique has advantages over previously reported ones, such as automated assembly of the sacrificial mould, and precise control over pore architecture/dimensions by 3D printing parameters. In this study, polydimethylsiloxane and biodegradable poly(ϵ-caprolactone) were used for fabrication. However, we show that this technique is also suitable for other biocompatible/biodegradable polymers. Various physical and mechanical properties of the dual-pore scaffolds were compared with control scaffolds with either only structured or only random pores, fabricated using previously reported methods. The fabricated dual-pore scaffolds supported high cell density, due to the random pores, in combination with uniform cell distribution throughout the scaffold, and higher cell proliferation and viability due to efficient nutrient/oxygen transport through the structured pores. In conclusion, the described fabrication technique is rapid, inexpensive, scalable, and compatible

  12. Water-based polyurethane 3D printed scaffolds with controlled release function for customized cartilage tissue engineering.

    PubMed

    Hung, Kun-Che; Tseng, Ching-Shiow; Dai, Lien-Guo; Hsu, Shan-hui

    2016-03-01

    Conventional 3D printing may not readily incorporate bioactive ingredients for controlled release because the process often involves the use of heat, organic solvent, or crosslinkers that reduce the bioactivity of the ingredients. Water-based 3D printing materials with controlled bioactivity for customized cartilage tissue engineering is developed in this study. The printing ink contains the water dispersion of synthetic biodegradable polyurethane (PU) elastic nanoparticles, hyaluronan, and bioactive ingredients TGFβ3 or a small molecule drug Y27632 to replace TGFβ3. Compliant scaffolds are printed from the ink at low temperature. These scaffolds promote the self-aggregation of mesenchymal stem cells (MSCs) and, with timely release of the bioactive ingredients, induce the chondrogenic differentiation of MSCs and produce matrix for cartilage repair. Moreover, the growth factor-free controlled release design may prevent cartilage hypertrophy. Rabbit knee implantation supports the potential of the novel 3D printing scaffolds in cartilage regeneration. We consider that the 3D printing composite scaffolds with controlled release bioactivity may have potential in customized tissue engineering. PMID:26774563

  13. Water-based polyurethane 3D printed scaffolds with controlled release function for customized cartilage tissue engineering.

    PubMed

    Hung, Kun-Che; Tseng, Ching-Shiow; Dai, Lien-Guo; Hsu, Shan-hui

    2016-03-01

    Conventional 3D printing may not readily incorporate bioactive ingredients for controlled release because the process often involves the use of heat, organic solvent, or crosslinkers that reduce the bioactivity of the ingredients. Water-based 3D printing materials with controlled bioactivity for customized cartilage tissue engineering is developed in this study. The printing ink contains the water dispersion of synthetic biodegradable polyurethane (PU) elastic nanoparticles, hyaluronan, and bioactive ingredients TGFβ3 or a small molecule drug Y27632 to replace TGFβ3. Compliant scaffolds are printed from the ink at low temperature. These scaffolds promote the self-aggregation of mesenchymal stem cells (MSCs) and, with timely release of the bioactive ingredients, induce the chondrogenic differentiation of MSCs and produce matrix for cartilage repair. Moreover, the growth factor-free controlled release design may prevent cartilage hypertrophy. Rabbit knee implantation supports the potential of the novel 3D printing scaffolds in cartilage regeneration. We consider that the 3D printing composite scaffolds with controlled release bioactivity may have potential in customized tissue engineering.

  14. The effect of porosity on cell ingrowth into accurately defined, laser-made, polylactide-based 3D scaffolds

    NASA Astrophysics Data System (ADS)

    Danilevicius, Paulius; Georgiadi, Leoni; Pateman, Christopher J.; Claeyssens, Frederik; Chatzinikolaidou, Maria; Farsari, Maria

    2015-05-01

    The aim of this study is to demonstrate the accuracy required for the investigation of the role of solid scaffolds' porosity in cell proliferation. We therefore present a qualitative investigation into the effect of porosity on MC3T3-E1 pre-osteoblastic cell ingrowth of three-dimensional (3D) scaffolds fabricated by direct femtosecond laser writing. The material we used is a purpose made photosensitive pre-polymer based on polylactide. We designed and fabricated complex, geometry-controlled 3D scaffolds with pore sizes ranging from 25 to 110 μm, representing porosities 70%, 82%, 86%, and 90%. The 70% porosity scaffolds did not support cell growth initially and in the long term. For the other porosities, we found a strong adhesion of the pre-osteoblastic cells from the first hours after seeding and a remarkable proliferation increase after 3 weeks and up to 8 weeks. The 86% porosity scaffolds exhibited a higher efficiency compared to 82% and 90%. In addition, bulk material degradation studies showed that the employed, highly-acrylated polylactide is degradable. These findings support the potential use of the proposed material and the scaffold fabrication technique in bone tissue engineering.

  15. Using Polymer Confinement for Stem Cell Differentiation: 3D Printed vs Molded Scaffolds

    NASA Astrophysics Data System (ADS)

    Rafailovich, Miriam

    Additive manufacturing technologies are increasingly being used to replace standard extrusion or molding methods in engineering polymeric biomedical implants, which can be further seeded with cells for tissue regeneration. The principal advantage of this new technology is the ability to print directly from a scan and hence produce parts which are an ideal fit for an individual, eliminating much of the sizing and fitting associated with standard manufacturing methods. The question though arises whether devices which may be macroscopically similar, serve identical functions and are produced from the same material, interact in the same manner with cells and living tissue. Here we show that fundamental differences can exist between 3-D printed and extruded scaffolds which can impact stem cell differentiation and lineage selection. We will show how polymer confinement inherent in these methods affect the printed features on multiple length scales. We will also and how the differentiation of stem cells is affected by substrate heterogeneity in both morphological and mechanical features. NSF-Inspire award # 1344267.

  16. Platelet lysate 3D scaffold supports mesenchymal stem cell chondrogenesis: an improved approach in cartilage tissue engineering.

    PubMed

    Moroz, Andrei; Bittencourt, Renata Aparecida Camargo; Almeida, Renan Padron; Felisbino, Sérgio Luis; Deffune, Elenice

    2013-01-01

    Articular lesions are still a major challenge in orthopedics because of cartilage's poor healing properties. A major improvement in therapeutics was the development of autologous chondrocytes implantation (ACI), a biotechnology-derived technique that delivers healthy autologous chondrocytes after in vitro expansion. To obtain cartilage-like tissue, 3D scaffolds are essential to maintain chondrocyte differentiated status. Currently, bioactive 3D scaffolds are promising as they can deliver growth factors, cytokines, and hormones to the cells, giving them a boost to attach, proliferate, induce protein synthesis, and differentiate. Using mesenchymal stem cells (MSCs) differentiated into chondrocytes, one can avoid cartilage harvesting. Thus, we investigated the potential use of a platelet-lysate-based 3D bioactive scaffold to support chondrogenic differentiation and maintenance of MSCs. The MSCs from adult rabbit bone marrow (n = 5) were cultivated and characterized using three antibodies by flow cytometry. MSCs (1 × 10(5)) were than encapsulated inside 60 µl of a rabbit platelet-lysate clot scaffold and maintained in Dulbecco's Modified Eagle Medium Nutrient Mixture F-12 supplemented with chondrogenic inductors. After 21 days, the MSCs-seeded scaffolds were processed for histological analysis and stained with toluidine blue. This scaffold was able to maintain round-shaped cells, typical chondrocyte metachromatic extracellular matrix deposition, and isogenous group formation. Cells accumulated inside lacunae and cytoplasm lipid droplets were other observed typical chondrocyte features. In conclusion, the usage of a platelet-lysate bioactive scaffold, associated with a suitable chondrogenic culture medium, supports MSCs chondrogenesis. As such, it offers an alternative tool for cartilage engineering research and ACI.

  17. Surfactant tuning of hydrophilicity of porous degradable copolymer scaffolds promotes cellular proliferation and enhances bone formation.

    PubMed

    Yassin, Mohammed A; Leknes, Knut N; Sun, Yang; Lie, Stein A; Finne-Wistrand, Anna; Mustafa, Kamal

    2016-08-01

    Poly(l-lactide-co-ɛ-caprolactone) (poly(LLA-co-CL)) has been blended with Tween 80 to tune the material properties and optimize cell-material interactions. Accordingly, the aims of this study were fourfold: to evaluate the effect of low concentrations of Tween 80 on the surface microstructure of 3D poly(LLA-co-CL) porous scaffolds: to determine the effect of different concentrations of Tween 80 on proliferation of bone marrow stromal cells (BMSCs) in vitro under dynamic cell culture at 7 and 21 days; to assess the influence of Tween 80 on the degradation rate of poly(LLA-co-CL) at 7 and 21 days; and in a subcutaneous rat model, to evaluate the effect on bone formation of porous scaffolds modified with 3% Tween 80 at 2 and 8 weeks. Blending 3% (w/w) Tween 80 with poly(LLA-co-CL) improves the surface wettability (p < 0.001). Poly(LLA-co-CL)/3% Tween 80 shows significantly increased cellular proliferation at days 7 and 21 (p < 0.001). Moreover, the presence of Tween 80 facilitates the degradation of poly(LLA-co-CL). Two weeks post-implantation, the poly(LLA-co-CL)/3% Tween 80 scaffolds exhibit significant mRNA expression of Runx2 (p = 0.004). After 8 weeks, poly(LLA-co-CL)/3% Tween 80 scaffolds show significantly increased de novo bone formation, demonstrated by μ-CT (p = 0.0133) and confirmed histologically. It can be concluded that blending 3% (w/w) Tween 80 with poly (LLA-co-CL) improves the hydrophilicity and osteogenic potential of the scaffolds. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2049-2059, 2016.

  18. Robotic deposition and in vitro characterization of 3D gelatin-bioactive glass hybrid scaffolds for biomedical applications.

    PubMed

    Gao, Chunxia; Rahaman, Mohamed N; Gao, Qiang; Teramoto, Akira; Abe, Koji

    2013-07-01

    The development of inorganic-organic hybrid scaffolds with controllable degradation and bioactive properties is receiving considerable interest for bone and tissue regeneration. The objective of this study was to create hybrid scaffolds of gelatin and bioactive glass (BG) with a controlled, three-dimensional (3D) architecture by a combined sol-gel and robotic deposition (robocasting) method and evaluate their mechanical response, bioactivity, and response to cells in vitro. Inks for robotic deposition of the scaffolds were prepared by dissolving gelatin in a sol-gel precursor solution of the bioactive glass (70SiO2 -25CaO-5P2 O5 ; mol%) and aging the solution to form a gel with the requisite viscosity. After drying and crosslinking, the gelatin-BG scaffolds, with a grid-like architecture (filament diameter ∼350 µm; pore width ∼550 µm), showed an elasto-plastic response, with a compressive strength of 5.1 ± 0.6 MPa, in the range of values for human trabecular bone (2-12 MPa). When immersed in phosphate-buffered saline, the crosslinked scaffolds rapidly absorbed water (∼440% of its dry weight after 2 h) and showed an elastic response at deformations up to ∼60%. Immersion of the scaffolds in a simulated body fluid resulted in the formation of a hydroxyapatite-like surface layer within 5 days, indicating their bioactivity in vitro. The scaffolds supported the proliferation, alkaline phosphatase activity, and mineralization of osteogenic MC3T3-E1 cells in vitro, showing their biocompatibility. Altogether, the results indicate that these gelatin-BG hybrid scaffolds with a controlled, 3D architecture of inter-connected pores have potential for use as implants for bone regeneration.

  19. Graded Porous β-Tricalcium Phosphate Scaffolds Enhance Bone Regeneration in Mandible Augmentation

    PubMed Central

    Yang, Jingwen; Kang, Yunqing; Browne, Christopher; Jiang, Ting; Yang, Yunzhi

    2015-01-01

    Abstract Bone augmentation requires scaffold to promote forming of natural bone structure. Currently, most of the reported bone scaffolds are porous solids with uniform pores. The aim of the currentstudy is to evaluate the effect of a graded porous β-tricalcium phosphate scaffolds on alveolar bone augmentation. Three groups of scaffolds were fabricated by a template-casting method: (1) graded porous scaffolds with large pores in the center and small pores at theperiphery, (2) scaffolds with large uniform pores, and (3) scaffolds with small uniform pores. Bone augmentation on rabbit mandible wasinvestigated by microcomputed tomography, sequential fluorescentlabeling, and histologic examination 3 months after implantation.The result presents that all the scaffold groups maintain their augmented bone height after 3-month observation, whereas the autograftinggroup presents an obvious bone resorption. Microcomputed tomography reveals that the graded porous group has significantly greater volume of new bone (P < 0.05) and similar bone density compared with the uniform pores groups. Bone substance distributes unevenly in all the 3 experimental groups. Greater bone volume can be observed in the area closer to the bone bed. The sequential fluorescentlabeling observation reveals robust bone regeneration in the first month and faster bone growth in the graded porous scaffold group than that in the large porous scaffold group. Histologic examinationsconfirm bone structure in the aspect of distribution, activity, and maturity. We conclude that graded porous designed biodegradableβ-tricalcium phosphate scaffolds are beneficial to promote bone augmentation in the aspect of bone volume. PMID:25675019

  20. Evaluation of synovium-derived mesenchymal stem cells and 3D printed nanocomposite scaffolds for tissue engineering

    NASA Astrophysics Data System (ADS)

    Pan, Jian-Feng; Li, Shuo; Guo, Chang-An; Xu, Du-Liang; Zhang, Feng; Yan, Zuo-Qin; Mo, Xiu-Mei

    2015-08-01

    Stem cells and scaffolds play a very important role in tissue engineering. Here, we isolated synovium-derived mesenchymal stem cells (SMSCs) from synovial membrane tissue and characterized stem-cell properties. Gelatin nanoparticles (NP) were prepared using a two-step desolvation method and then pre-mixed into different host matrix (silk fibroin (SF), gelatin (Gel), or SF-Gel mixture) to generate various 3D printed nanocomposite scaffolds (NP/SF, NP/SF-Gel, NP/Gel-1, and NP/Gel-2). The microstructure was examined by scanning electron microscopy. Biocompatibility assessment was performed through CCK-8 assay by coculturing with SMSCs at 1, 3, 7 and 14 days. According to the results, SMSCs are similar to other MSCs in their surface epitope expression, which are negative for CD45 and positive for CD44, CD90, and CD105. After incubation in lineage-specific medium, SMSCs could differentiate into chondrocytes, osteocytes and adipocytes. 3D printed nanocomposite scaffolds exhibited a good biocompatibility in the process of coculturing with SMSCs and had no negative effect on cell behavior. The study provides a strategy to obtain SMSCs and fabricate 3D printed nanocomposite scaffolds, the combination of which could be used for practical applications in tissue engineering.

  1. Poly(dopamine) coating of 3D printed poly(lactic acid) scaffolds for bone tissue engineering.

    PubMed

    Kao, Chia-Tze; Lin, Chi-Chang; Chen, Yi-Wen; Yeh, Chia-Hung; Fang, Hsin-Yuan; Shie, Ming-You

    2015-11-01

    3D printing is a versatile technique to generate large quantities of a wide variety of shapes and sizes of polymer. The aim of this study is to develop functionalized 3D printed poly(lactic acid) (PLA) scaffolds and use a mussel-inspired surface coating to regulate cell adhesion, proliferation and differentiation of human adipose-derived stem cells (hADSCs). We prepared PLA 3D scaffolds coated with polydopamine (PDA). The chemical composition and surface properties of PDA/PLA were characterized by XPS. PDA/PLA modulated hADSCs' responses in several ways. Firstly, adhesion and proliferation, and cell cycle of hADSCs cultured on PDA/PLA were significantly enhanced relative to those on PLA. In addition, the collagen I secreted from cells was increased and promoted cell attachment and cell cycle progression were depended on the PDA content. In osteogenesis assay, the ALP activity and osteocalcin of hADSCs cultured on PDA/PLA were significantly higher than seen in those cultured on pure PLA scaffolds. Moreover, hADSCs cultured on PDA/PLA showed up-regulation of the ang-1 and vWF proteins associated with angiogenic differentiation. Our results demonstrate that the bio-inspired coating synthetic PLA polymer can be used as a simple technique to render the surfaces of synthetic scaffolds active, thus enabling them to direct the specific responses of hADSCs.

  2. A miniature microbial fuel cell with conducting nanofibers-based 3D porous biofilm

    NASA Astrophysics Data System (ADS)

    Jiang, Huawei; Halverson, Larry J.; Dong, Liang

    2015-12-01

    Miniature microbial fuel cell (MFC) technology has received growing interest due to its potential applications in high-throughput screening of bacteria and mutants to elucidate mechanisms of electricity generation. This paper reports a novel miniature MFC with an improved output power density and short startup time, utilizing electrospun conducting poly(3,4-ethylenedioxythiophene) (PEDOT) nanofibers as a 3D porous anode within a 12 μl anolyte chamber. This device results in 423 μW cm-3 power density based on the volume of the anolyte chamber, using Shewanella oneidensis MR-1 as a model biocatalyst without any optimization of bacterial culture. The device also excels in a startup time of only 1hr. The high conductivity of the electrospun nanofibers makes them suitable for efficient electron transfer. The mean pore size of the conducting nanofibers is several micrometers, which is favorable for bacterial penetration and colonization of surfaces of the nanofibers. We demonstrate that S. oneidensis can fully colonize the interior region of this nanofibers-based porous anode. This work represents a new attempt to explore the use of electrospun PEDOT nanofibers as a 3D anode material for MFCs. The presented miniature MFC potentially will provide a high-sensitivity, high-throughput tool to screen suitable bacterial species and mutant strains for use in large-size MFCs.

  3. An endothelial cultured condition medium embedded porous PLGA scaffold for the enhancement of mouse embryonic stem cell differentiation.

    PubMed

    Li, Ching-Wen; Pan, Wei-Ting; Ju, Jyh-Cherng; Wang, Gou-Jen

    2016-04-01

    In this study, we have developed a microporous poly(lactic-co-glycolic acid) (PLGA) scaffold that combines a continuous release property and a three-dimensional (3D) scaffolding technique for the precise and efficient formation of endothelial cell lineage from embryonic stem cells (ESCs). Eight PLGA scaffolds (14.29%, 16.67%, 20% and 25% concentrations of PLGA solutions) mixed with two crystal sizes of sodium chloride (NaCl) were fabricated by leaching. Then, vascular endothelial cell conditioned medium (ECCM) mixed with gelatin was embedded into the scaffold for culturing of mouse embryonic stem cells (mESCs). The 14.29% PLGA scaffolds fabricated using non-ground NaCl particles (NG-PLGA) and the 25% PLGA containing scaffolds fabricated using ground NaCl particles (G-PLGA) possessed minimum and maximum moisture content and bovine serum albumin (BSA) content properties, respectively. These two groups of scaffolds were used for future experiments in this study. Cell culture results demonstrated that the proposed porous scaffolds without growth factors were sufficient to induce mouse ESCs to differentiate into endothelial-like cells in the early culture stages, and combined with embedded ECCM could provide a long-term inducing system for ESC differentiation. PMID:27068738

  4. A combinatorial variation in surface chemistry and pore size of three-dimensional porous poly(ε-caprolactone) scaffolds modulates the behaviors of mesenchymal stem cells.

    PubMed

    Zhao, Yingdi; Tan, Ke; Zhou, Yan; Ye, Zhaoyang; Tan, Wen-Song

    2016-02-01

    Biomaterial properties play significant roles in controlling cellular behaviors. The objective of the present study was to investigate how pore size and surface chemistry of three-dimensional (3D) porous scaffolds regulate the fate of mesenchymal stem cells (MSCs) in vitro in combination. First, on poly(ε-caprolactone) (PCL) films, the hydrolytic treatment was found to stimulate the adhesion, spreading and proliferation of human MSCs (hMSCs) in comparison with pristine films, while the aminolysis showed mixed effects. Then, 3D porous PCL scaffolds with varying pore sizes (100-200μm, 200-300μm and 300-450μm) were fabricated and subjected to either hydrolysis or aminolysis. It was found that a pore size of 200-300μm with hydrolysis in 3D scaffolds was the most favorable condition for growth of hMSCs. Importantly, while a pore size of 200-300μm with hydrolysis for 1h supported the best osteogenic differentiation of hMSCs, the chondrogenic differentiation was greatest in scaffolds with a pore size of 300-450μm and treated with aminolysis for 1h. Taken together, these results suggest that surface chemistry and pore size of 3D porous scaffolds may potentially have a synergistic impact on the behaviors of MSCs.

  5. Exploiting novel sterilization techniques for porous polyurethane scaffolds.

    PubMed

    Bertoldi, Serena; Farè, Silvia; Haugen, Håvard Jostein; Tanzi, Maria Cristina

    2015-05-01

    Porous polyurethane (PU) structures raise increasing interest as scaffolds in tissue engineering applications. Understanding the effects of sterilization on their properties is mandatory to assess their potential use in the clinical practice. The aim of this work is the evaluation of the effects of two innovative sterilization techniques (i.e. plasma, Sterrad(®) system, and ozone) on the morphological, chemico-physical and mechanical properties of a PU foam synthesized by gas foaming, using water as expanding agent. In addition, possible toxic effects of the sterilization were evaluated by in vitro cytotoxicity tests. Plasma sterilization did not affect the morphological and mechanical properties of the PU foam, but caused at some extent degradative phenomena, as detected by infrared spectroscopy. Ozone sterilization had a major effect on foam morphology, causing the formation of new small pores, and stronger degradation and oxidation on the structure of the material. These modifications affected the mechanical properties of the sterilized PU foam too. Even though, no cytotoxic effects were observed after both plasma and ozone sterilization, as confirmed by the good values of cell viability assessed by Alamar Blue assay. The results here obtained can help in understanding the effects of sterilization procedures on porous polymeric scaffolds, and how the scaffold morphology, in particular porosity, can influence the effects of sterilization, and viceversa. PMID:25893387

  6. 3D bioprinting of BMSC-laden methacrylamide gelatin scaffolds with CBD-BMP2-collagen microfibers.

    PubMed

    Du, Mingchun; Chen, Bing; Meng, Qingyuan; Liu, Sumei; Zheng, Xiongfei; Zhang, Cheng; Wang, Heran; Li, Hongyi; Wang, Nuo; Dai, Jianwu

    2015-01-01

    Three-dimensional (3D) bioprinting combines biomaterials, cells and functional components into complex living tissues. Herein, we assembled function-control modules into cell-laden scaffolds using 3D bioprinting. A customized 3D printer was able to tune the microstructure of printed bone mesenchymal stem cell (BMSC)-laden methacrylamide gelatin scaffolds at the micrometer scale. For example, the pore size was adjusted to 282 ± 32 μm and 363 ± 60 μm. To match the requirements of the printing nozzle, collagen microfibers with a length of 22 ± 13 μm were prepared with a high-speed crusher. Collagen microfibers bound bone morphogenetic protein 2 (BMP2) with a collagen binding domain (CBD) as differentiation-control module, from which BMP2 was able to be controllably released. The differentiation behaviors of BMSCs in the printed scaffolds were compared in three microenvironments: samples without CBD-BMP2-collagen microfibers in the growth medium, samples without microfibers in the osteogenic medium and samples with microfibers in the growth medium. The results indicated that BMSCs showed high cell viability (>90%) during printing; CBD-BMP2-collagen microfibers induced BMSC differentiation into osteocytes within 14 days more efficiently than the osteogenic medium. Our studies suggest that these function-control modules are attractive biomaterials and have potential applications in 3D bioprinting. PMID:26684899

  7. 3D bioprinting of BMSC-laden methacrylamide gelatin scaffolds with CBD-BMP2-collagen microfibers.

    PubMed

    Du, Mingchun; Chen, Bing; Meng, Qingyuan; Liu, Sumei; Zheng, Xiongfei; Zhang, Cheng; Wang, Heran; Li, Hongyi; Wang, Nuo; Dai, Jianwu

    2015-01-01

    Three-dimensional (3D) bioprinting combines biomaterials, cells and functional components into complex living tissues. Herein, we assembled function-control modules into cell-laden scaffolds using 3D bioprinting. A customized 3D printer was able to tune the microstructure of printed bone mesenchymal stem cell (BMSC)-laden methacrylamide gelatin scaffolds at the micrometer scale. For example, the pore size was adjusted to 282 ± 32 μm and 363 ± 60 μm. To match the requirements of the printing nozzle, collagen microfibers with a length of 22 ± 13 μm were prepared with a high-speed crusher. Collagen microfibers bound bone morphogenetic protein 2 (BMP2) with a collagen binding domain (CBD) as differentiation-control module, from which BMP2 was able to be controllably released. The differentiation behaviors of BMSCs in the printed scaffolds were compared in three microenvironments: samples without CBD-BMP2-collagen microfibers in the growth medium, samples without microfibers in the osteogenic medium and samples with microfibers in the growth medium. The results indicated that BMSCs showed high cell viability (>90%) during printing; CBD-BMP2-collagen microfibers induced BMSC differentiation into osteocytes within 14 days more efficiently than the osteogenic medium. Our studies suggest that these function-control modules are attractive biomaterials and have potential applications in 3D bioprinting.

  8. Expansion of Human Mesenchymal Stromal Cells from Fresh Bone Marrow in a 3D Scaffold-Based System under Direct Perfusion

    PubMed Central

    Brachat, Sophie; Braccini, Alessandra; Wendt, David; Barbero, Andrea; Jacobi, Carsten; Martin, Ivan

    2014-01-01

    Mesenchymal stromal/stem cell (MSC) expansion in conventional monolayer culture on plastic dishes (2D) leads to progressive loss of functionality and thus challenges fundamental studies on the physiology of skeletal progenitors, as well as translational applications for cellular therapy and molecular medicine. Here we demonstrate that 2D MSC expansion can be entirely bypassed by culturing freshly isolated bone marrow nucleated cells within 3D porous scaffolds in a perfusion-based bioreactor system. The 3D-perfusion system generated a stromal tissue that could be enzymatically treated to yield CD45- MSC. As compared to 2D-expanded MSC (control), those derived from 3D-perfusion culture after the same time (3 weeks) or a similar extent of proliferation (7–8 doublings) better maintained their progenitor properties, as assessed by a 4.3-fold higher clonogenicity and the superior differentiation capacity towards all typical mesenchymal lineages. Transcriptomic analysis of MSC from 5 donors validated the robustness of the process and indicated a reduced inter-donor variability and a significant upregulation of multipotency-related gene clusters following 3D-perfusion- as compared to 2D-expansion. Interestingly, the differences in functionality and transcriptomics between MSC expanded in 2D or under 3D-perfusion were only partially captured by cytofluorimetric analysis using conventional surface markers. The described system offers a multidisciplinary approach to study how factors of a 3D engineered niche regulate MSC function and, by streamlining conventional labor-intensive processes, is prone to automation and scalability within closed bioreactor systems. PMID:25020062

  9. In vivo biocompatibility and mechanical properties of porous zein scaffolds.

    PubMed

    Wang, Hua-Jie; Gong, Sheng-Ju; Lin, Zhi-Xin; Fu, Jian-Xi; Xue, Song-Tao; Huang, Jing-Chun; Wang, Jin-Ye

    2007-09-01

    In our previous study, a three-dimensional zein porous scaffold with a compressive Young's modulus of up to 86.6+/-19.9 MPa and a compressive strength of up to 11.8+/-1.7 MPa was prepared, and was suitable for culture of mesenchymal stem cells (MSCs) in vitro. In this study, we examined its tissue compatibility in a rabbit subcutaneous implantation model; histological analysis revealed a good tissue response and degradability. To improve its mechanical property (especially the brittleness), the scaffolds were prepared using the club-shaped mannitol as the porogen, and stearic acid or oleic acid was added. The scaffolds obtained had an interconnected tubular pore structure, 100-380 microm in pore size, and about 80% porosity. The maximum values of the compressive strength and modulus, the tensile strength and modulus, and the flexural strength and modulus were obtained at the lowest porosity, reaching 51.81+/-8.70 and 563.8+/-23.4 MPa; 3.91+/-0.86 and 751.63+/-58.85 MPa; and 17.71+/-3.02 and 514.39+/-19.02 MPa, respectively. Addition of 15% stearic acid or 20% oleic acid did not affect the proliferation and osteogenic differentiation of MSCs, and a successful improvement of mechanical properties, especially the brittleness of the zein scaffold could be achieved.

  10. The effect of interface microstructure on interfacial shear strength for osteochondral scaffolds based on biomimetic design and 3D printing.

    PubMed

    Zhang, Weijie; Lian, Qin; Li, Dichen; Wang, Kunzheng; Hao, Dingjun; Bian, Weiguo; Jin, Zhongmin

    2015-01-01

    Interface integration between chondral phase and osseous phase is crucial in engineered osteochondral scaffolds. However, the integration was poorly understood and commonly failed to meet the need of osteochondral scaffolds. In this paper, a biphasic polyethylene glycol (PEG)/β-tricalcium phosphate (β-TCP) scaffold with enhanced interfacial integration was developed. The chondral phase was a PEG hydrogel. The osseous phase was a β-TCP ceramic scaffold. The PEG hydrogel was directly cured on the ceramic interface layer by layer to fabricate osteochondral scaffolds by 3D printing technology. Meanwhile, a series of interface structure were designed with different interface pore area percentages (0/10/20/30/40/50/60%), and interfacial shear test was applied for interface structure optimization (n=6 samples/group). The interfacial shear strength of 30% pore area group was nearly three folds improved compared with that of 0% pore area percentage group, and more than fifty folds improved compared with that of traditional integration (5.91±0.59 kPa). In conclusion, the biomimetic PEG/β-TCP scaffolds with interface structure enhanced integration show promising potential application for osteochondral tissue engineering.

  11. The effect of interface microstructure on interfacial shear strength for osteochondral scaffolds based on biomimetic design and 3D printing.

    PubMed

    Zhang, Weijie; Lian, Qin; Li, Dichen; Wang, Kunzheng; Hao, Dingjun; Bian, Weiguo; Jin, Zhongmin

    2015-01-01

    Interface integration between chondral phase and osseous phase is crucial in engineered osteochondral scaffolds. However, the integration was poorly understood and commonly failed to meet the need of osteochondral scaffolds. In this paper, a biphasic polyethylene glycol (PEG)/β-tricalcium phosphate (β-TCP) scaffold with enhanced interfacial integration was developed. The chondral phase was a PEG hydrogel. The osseous phase was a β-TCP ceramic scaffold. The PEG hydrogel was directly cured on the ceramic interface layer by layer to fabricate osteochondral scaffolds by 3D printing technology. Meanwhile, a series of interface structure were designed with different interface pore area percentages (0/10/20/30/40/50/60%), and interfacial shear test was applied for interface structure optimization (n=6 samples/group). The interfacial shear strength of 30% pore area group was nearly three folds improved compared with that of 0% pore area percentage group, and more than fifty folds improved compared with that of traditional integration (5.91±0.59 kPa). In conclusion, the biomimetic PEG/β-TCP scaffolds with interface structure enhanced integration show promising potential application for osteochondral tissue engineering. PMID:25491954

  12. Fabrication and characterization of strontium incorporated 3-D bioactive glass scaffolds for bone tissue from biosilica.

    PubMed

    Özarslan, Ali Can; Yücel, Sevil

    2016-11-01

    Bioactive glass scaffolds that contain silica are high viable biomaterials as bone supporters for bone tissue engineering due to their bioactive behaviour in simulated body fluid (SBF). In the human body, these materials help inorganic bone structure formation due to a combination of the particular ratio of elements such as silicon (Si), calcium (Ca), sodium (Na) and phosphorus (P), and the doping of strontium (Sr) into the scaffold structure increases their bioactive behaviour. In this study, bioactive glass scaffolds were produced by using rice hull ash (RHA) silica and commercial silica based bioactive glasses. The structural properties of scaffolds such as pore size, porosity and also the bioactive behaviour were investigated. The results showed that undoped and Sr-doped RHA silica-based bioactive glass scaffolds have better bioactivity than that of commercial silica based bioactive glass scaffolds. Moreover, undoped and Sr-doped RHA silica-based bioactive glass scaffolds will be able to be used instead of undoped and Sr-doped commercial silica based bioactive glass scaffolds for bone regeneration applications. Scaffolds that are produced from undoped or Sr-doped RHA silica have high potential to form new bone for bone defects in tissue engineering.

  13. Fabrication and characterization of strontium incorporated 3-D bioactive glass scaffolds for bone tissue from biosilica.

    PubMed

    Özarslan, Ali Can; Yücel, Sevil

    2016-11-01

    Bioactive glass scaffolds that contain silica are high viable biomaterials as bone supporters for bone tissue engineering due to their bioactive behaviour in simulated body fluid (SBF). In the human body, these materials help inorganic bone structure formation due to a combination of the particular ratio of elements such as silicon (Si), calcium (Ca), sodium (Na) and phosphorus (P), and the doping of strontium (Sr) into the scaffold structure increases their bioactive behaviour. In this study, bioactive glass scaffolds were produced by using rice hull ash (RHA) silica and commercial silica based bioactive glasses. The structural properties of scaffolds such as pore size, porosity and also the bioactive behaviour were investigated. The results showed that undoped and Sr-doped RHA silica-based bioactive glass scaffolds have better bioactivity than that of commercial silica based bioactive glass scaffolds. Moreover, undoped and Sr-doped RHA silica-based bioactive glass scaffolds will be able to be used instead of undoped and Sr-doped commercial silica based bioactive glass scaffolds for bone regeneration applications. Scaffolds that are produced from undoped or Sr-doped RHA silica have high potential to form new bone for bone defects in tissue engineering. PMID:27524030

  14. Stress-strain analysis of porous scaffolds made from titanium alloys synthesized via SLS method

    NASA Astrophysics Data System (ADS)

    Shishkovsky, I.

    2009-09-01

    A layer-by-layer selective laser sintering (SLS) technology seems to be greatly promising for solving the plastic surgery problems, particularly those pertaining to the facial reconstruction. Made from titanium-based alloys (titanium or nitinol, i.e. NiTi-intermetallic phase), the porous scaffolds for cranioplasty are an efficient tool for rectifying the face defects and for the dental orthopedic surgery. The progress in the oral surgery and teeth implantation is caused by the problem of an osteointegration on the one hand, and by achievements of the implant synthesis techniques, on the other hand. An important problem thereby is a profound study of the stress-strain behavior of porous implants under the masticatory load or pressure. In the present study the ways for the optimization of the porous implant structural and strength properties as the function of the laser synthesis parameters are described. The finite element approach (ANSYS) was used here for a complex dowel description and numerical simulations. In order to evaluate the processes in the porous implant under the external loading, a CAD 3D model was built for different internal and external configurations of the implant and/or initial shape of powdered particles. The stress-strain dependences were calculated that displayed the irregularity of the stress distribution by the implant volume in the bone tissue. Most of the values are concentrated in places of object contact.

  15. Porous nanoapatite scaffolds synthesized using an approach of interfacial mineralization reaction and their bioactivity.

    PubMed

    Wang, Jianxin; Yan, Haoran; Chen, Taijun; Wang, Yingying; Li, Huiyong; Zhi, Wei; Feng, Bo; Weng, Jie; Zhu, Minghua

    2014-11-01

    There is a growing interest in the use of calcium phosphate, used to fabricate porous scaffolds for bone tissue regeneration and repair. However, it is difficult to obtain interconnected pores with very high porosity and to engineer the topography of the pore walls for calcium phosphate ceramic scaffolds. In this study, a novelty method interfacial mineralization reaction was used to fabricate porous nano-calcium phosphate ceramic scaffolds with three-dimensional surface topography of walls, which was tuned using different surfactants; using this method, porous scaffolds with different shapes were obtained, which demonstrates that interfacial mineralization reaction is not only a good method to prepare porous ceramic scaffolds of calcium phosphate but also an efficient approach to engineer the topography of the pore walls. The as-prepared porous ceramic scaffolds have also been proved to have good biocompatibility, bioactivity, and biodegradability, which are necessary for the clinical application. In vivo experimental results revealed that not only osteoconduction but also osteoinduction was responsible for the bone formation in our scaffolds, which accelerated the formation of new bone, and that the degradation process of our porous scaffolds could match osteoinduction, mineralization of matrix and bone, and reconstruction of new bone very well, and porous scaffolds could be completely substituted by the new bone.

  16. Development of a Bioreactor to Culture Tissue Engineered Ureters Based on the Application of Tubular OPTIMAIX 3D Scaffolds.

    PubMed

    Seifarth, Volker; Gossmann, Matthias; Janke, Heinz Peter; Grosse, Joachim O; Becker, Christoph; Heschel, Ingo; Artmann, Gerhard M; Temiz Artmann, Aysegül

    2015-01-01

    Regenerative medicine, tissue engineering and biomedical research give hope to many patients who need bio-implants. Tissue engineering applications have already been developed based on bioreactors. Physiological ureter implants, however, do not still function sufficiently, as they represent tubular hollow structures with very specific cellular structures and alignments consisting of several cell types. The aim of this study was to a develop a new bioreactor system based on seamless, collagenous, tubular OPTIMAIX 3D prototype sponge as scaffold material for ex-vivo culturing of a tissue engineered ureter replacement for future urological applications. Particular emphasis was given to a great extent to mimic the physiological environment similar to the in vivo situation of a ureter. NIH-3T3 fibroblasts, C2C12, Urotsa and primary genitourinary tract cells were applied as co-cultures on the scaffold and the penetration of cells into the collagenous material was followed. By the end of this study, the bioreactor was functioning, physiological parameter as temperature and pH and the newly developed BIOREACTOR system is applicable to tubular scaffold materials with different lengths and diameters. The automatized incubation system worked reliably. The tubular OPTIMAIX 3D sponge was a suitable scaffold material for tissue engineering purposes and co-cultivation procedures.

  17. Hydroxyapatite-silver nanoparticles coatings on porous polyurethane scaffold.

    PubMed

    Ciobanu, Gabriela; Ilisei, Simona; Luca, Constantin

    2014-02-01

    The present paper is focused on a study regarding the possibility of obtaining hydroxyapatite-silver nanoparticle coatings on porous polyurethane scaffold. The method applied is based on a combined strategy involving hydroxyapatite biomimetic deposition on polyurethane surface using a Supersaturated Calcification Solution (SCS), combined with silver ions reduction and in-situ crystallization processes on hydroxyapatite-polyurethane surface by sample immersing in AgNO3 solution. The morphology, composition and phase structure of the prepared samples were characterized by scanning electron microscopy coupled with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray diffraction (XRD), UV-Vis spectroscopy and X-ray photoelectron spectroscopy (XPS) measurements. The data obtained show that a layer of hydroxyapatite was deposited on porous polyurethane support and the silver nanoparticles (average size 34.71 nm) were dispersed among and even on the hydroxyapatite crystals. Hydroxyapatite/polyurethane surface acts as a reducer and a stabilizing agent for silver ions. The surface plasmon resonance peak in UV-Vis absorption spectra showed an absorption maximum at 415 nm, indicating formation of silver nanoparticles. The hydroxyapatite-silver polyurethane scaffolds were tested against Staphylococcus aureus and Escherichia coli and the obtained data were indicative of good antibacterial properties of the materials.

  18. 3D-printed dimethyloxallyl glycine delivery scaffolds to improve angiogenesis and osteogenesis.

    PubMed

    Min, Zhu; Shichang, Zhao; Chen, Xin; Yufang, Zhu; Changqing, Zhang

    2015-08-01

    Angiogenesis-osteogenesis coupling processes are vital in bone tissue engineering. Normal biomaterials implanted in bone defects have issues in the sufficient formation of blood vessels, especially in the central part. Single delivery of vascular endothelial growth factors (VEGF) to foci in previous studies did not show satisfactory results due to low loading doses, a short protein half-life and low efficiency. Development of a hypoxia-mimicking microenvironment for cells by local prolyl-4-hydroxylase inhibitor release, which can stabilize hypoxia-inducible factor 1α (HIF-1α) expression, is an alternative method. The aim of this study was to design a dimethyloxallyl glycine (DMOG) delivering scaffold composed of mesoporous bioactive glasses and poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) polymers (MPHS scaffolds), so as to investigate whether the sustained release of DMOG promotes local angiogenesis and bone healing. The morphology and microstructure of composite scaffolds were characterized. The DMOG release patterns from scaffolds loaded with different DMOG dosages were evaluated, and the effects of DMOG delivery on human bone marrow stromal cell (hBMSC) adhesion, viability, proliferation, osteogenic differentiation and angiogenic-relative gene expressions with scaffolds were also investigated. In vivo studies were carried out to observe vascular formations and new bone ingrowth with DMOG-loaded scaffolds. The results showed that DMOG could be released in a sustained manner over 4 weeks from MPHS scaffolds and obviously enhance the angiogenesis and osteogenesis in the defects. Microfil perfusion showed a significantly increased formation of vessels in the defects with DMOG delivery. Furthermore, micro-CT imaging and fluorescence labeling indicated larger areas of bone formation for DMOG-loaded scaffolds. It is concluded that MPHS-DMOG scaffolds are promising for enhancing bone healing of osseous defects. PMID:26222039

  19. Multi-contrast 3D X-ray imaging of porous and composite materials

    SciTech Connect

    Sarapata, Adrian; Herzen, Julia; Ruiz-Yaniz, Maite; Zanette, Irene; Rack, Alexander; Pfeiffer, Franz

    2015-04-13

    Grating-based X-ray computed tomography allows for simultaneous and nondestructive determination of the full X-ray complex index of refraction and the scattering coefficient distribution inside an object in three dimensions. Its multi-contrast capabilities combined with a high resolution of a few micrometers make it a suitable tool for assessing multiple phases inside porous and composite materials such as concrete. Here, we present quantitative results of a proof-of-principle experiment performed on a concrete sample. Thanks to the complementarity of the contrast channels, more concrete phases could be distinguished than in conventional attenuation-based imaging. The phase-contrast reconstruction shows high contrast between the hardened cement paste and the aggregates and thus allows easy 3D segmentation. Thanks to the dark-field image, micro-cracks inside the coarse aggregates are visible. We believe that these results are extremely interesting in the field of porous and composite materials studies because of unique information provided by grating interferometry in a non-destructive way.

  20. Spinal cord organotypic slice cultures for the study of regenerating motor axon interactions with 3D scaffolds.

    PubMed

    Gerardo-Nava, Jose; Hodde, Dorothee; Katona, Istvan; Bozkurt, Ahmet; Grehl, Torsten; Steinbusch, Harry W M; Weis, Joachim; Brook, Gary A

    2014-05-01

    Numerous in-vitro techniques exist for investigating the influence of 3D substrate topography on sensory axon growth. However, simple and cost-effective methods for studying post-natal motor axon interactions with such substrates are lacking. Here, spinal cord organotypic slice cultures (OSC) from post-natal day 7-9 rat pups were presented with spinal nerve roots, or blocks of fibrin hydrogel or 3D microporous collagen scaffolds to investigate motor axon-substrate interactions. By 7-14 days, axons from motor neuronal pools extended into the explanted nerve roots, growing along Schwann cell processes and demonstrating a full range of axon-Schwann cell interactions, from simple ensheathment to concentric wrapping by Schwann cell processes and the formation of compact myelin within a basal lamina sheath. Extensive motor axon regeneration and all stages of axon-Schwann interactions were also supported within the longitudinally orientated microporous framework of the 3D collagen scaffold. In stark contrast, the simple fibrin hydrogel only supported axon growth and cell migration over its surface. The relative ease of demonstrating such motor axon regeneration through the microporous 3D framework by immunofluorescence, two-photon microscopy and transmission electron microscopy strongly supports the adoption of this technique for assaying the influence of substrate topography and functionalization in regenerative bioengineering.

  1. Strategies for the chemical analysis of highly porous bone scaffolds using secondary ion mass spectrometry.

    PubMed

    Wang, Daming; Poologasundarampillai, Gowsihan; van den Bergh, Wouter; Chater, Richard J; Kasuga, Toshihiro; Jones, Julian R; McPhail, David S

    2014-02-01

    Understanding the distribution of critical elements (e.g. silicon and calcium) within silica-based bone scaffolds synthesized by different methods is central to the optimization of these materials. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) has been used to determine this information due to its very high surface sensitivity and its ability to map all the elements and compounds in the periodic table with high spatial resolution. The SIMS image data can also be combined with depth profiles to construct three-dimensional chemical maps. However, the scaffolds have interconnected pore networks, which are very challenging structures for the SIMS technique. To overcome this problem two experimental methodologies have been developed. The first method involved the use of the focused ion beam technique to obtain clear images of the regions of interest and subsequently mark them by introducing fiducial marks; the samples were then analysed using the ToF-SIMS technique to yield the chemical analyses of the regions of interest. The second method involved impregnating the pores using a suitable reagent so that a flat surface could be achieved, and this was followed by secondary ion mapping and 3D chemical imaging with ToF-SIMS. The samples used in this work were sol-gel 70S30C foam and electrospun fibres and calcium-containing silica/gelatin hybrid scaffolds. The results demonstrate the feasibility of both these experimental methodologies and indicate that these methods can provide an opportunity to compare various artificial bone scaffolds, which will be of help in improving scaffold synthesis and processing routes. The techniques are also transferable to many other types of porous material. PMID:24457328

  2. Strategies for the chemical analysis of highly porous bone scaffolds using secondary ion mass spectrometry.

    PubMed

    Wang, Daming; Poologasundarampillai, Gowsihan; van den Bergh, Wouter; Chater, Richard J; Kasuga, Toshihiro; Jones, Julian R; McPhail, David S

    2014-02-01

    Understanding the distribution of critical elements (e.g. silicon and calcium) within silica-based bone scaffolds synthesized by different methods is central to the optimization of these materials. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) has been used to determine this information due to its very high surface sensitivity and its ability to map all the elements and compounds in the periodic table with high spatial resolution. The SIMS image data can also be combined with depth profiles to construct three-dimensional chemical maps. However, the scaffolds have interconnected pore networks, which are very challenging structures for the SIMS technique. To overcome this problem two experimental methodologies have been developed. The first method involved the use of the focused ion beam technique to obtain clear images of the regions of interest and subsequently mark them by introducing fiducial marks; the samples were then analysed using the ToF-SIMS technique to yield the chemical analyses of the regions of interest. The second method involved impregnating the pores using a suitable reagent so that a flat surface could be achieved, and this was followed by secondary ion mapping and 3D chemical imaging with ToF-SIMS. The samples used in this work were sol-gel 70S30C foam and electrospun fibres and calcium-containing silica/gelatin hybrid scaffolds. The results demonstrate the feasibility of both these experimental methodologies and indicate that these methods can provide an opportunity to compare various artificial bone scaffolds, which will be of help in improving scaffold synthesis and processing routes. The techniques are also transferable to many other types of porous material.

  3. Rapid prototyped porous nickel-titanium scaffolds as bone substitutes.

    PubMed

    Hoffmann, Waldemar; Bormann, Therese; Rossi, Antonella; Müller, Bert; Schumacher, Ralf; Martin, Ivan; de Wild, Michael; Wendt, David

    2014-01-01

    While calcium phosphate-based ceramics are currently the most widely used materials in bone repair, they generally lack tensile strength for initial load bearing. Bulk titanium is the gold standard of metallic implant materials, but does not match the mechanical properties of the surrounding bone, potentially leading to problems of fixation and bone resorption. As an alternative, nickel-titanium alloys possess a unique combination of mechanical properties including a relatively low elastic modulus, pseudoelasticity, and high damping capacity, matching the properties of bone better than any other metallic material. With the ultimate goal of fabricating porous implants for spinal, orthopedic and dental applications, nickel-titanium substrates were fabricated by means of selective laser melting. The response of human mesenchymal stromal cells to the nickel-titanium substrates was compared to mesenchymal stromal cells cultured on clinically used titanium. Selective laser melted titanium as well as surface-treated nickel-titanium and titanium served as controls. Mesenchymal stromal cells had similar proliferation rates when cultured on selective laser melted nickel-titanium, clinically used titanium, or controls. Osteogenic differentiation was similar for mesenchymal stromal cells cultured on the selected materials, as indicated by similar gene expression levels of bone sialoprotein and osteocalcin. Mesenchymal stromal cells seeded and cultured on porous three-dimensional selective laser melted nickel-titanium scaffolds homogeneously colonized the scaffold, and following osteogenic induction, filled the scaffold's pore volume with extracellular matrix. The combination of bone-related mechanical properties of selective laser melted nickel-titanium with its cytocompatibility and support of osteogenic differentiation of mesenchymal stromal cells highlights its potential as a superior bone substitute as compared to clinically used titanium.

  4. Rapid prototyped porous nickel-titanium scaffolds as bone substitutes.

    PubMed

    Hoffmann, Waldemar; Bormann, Therese; Rossi, Antonella; Müller, Bert; Schumacher, Ralf; Martin, Ivan; de Wild, Michael; Wendt, David

    2014-01-01

    While calcium phosphate-based ceramics are currently the most widely used materials in bone repair, they generally lack tensile strength for initial load bearing. Bulk titanium is the gold standard of metallic implant materials, but does not match the mechanical properties of the surrounding bone, potentially leading to problems of fixation and bone resorption. As an alternative, nickel-titanium alloys possess a unique combination of mechanical properties including a relatively low elastic modulus, pseudoelasticity, and high damping capacity, matching the properties of bone better than any other metallic material. With the ultimate goal of fabricating porous implants for spinal, orthopedic and dental applications, nickel-titanium substrates were fabricated by means of selective laser melting. The response of human mesenchymal stromal cells to the nickel-titanium substrates was compared to mesenchymal stromal cells cultured on clinically used titanium. Selective laser melted titanium as well as surface-treated nickel-titanium and titanium served as controls. Mesenchymal stromal cells had similar proliferation rates when cultured on selective laser melted nickel-titanium, clinically used titanium, or controls. Osteogenic differentiation was similar for mesenchymal stromal cells cultured on the selected materials, as indicated by similar gene expression levels of bone sialoprotein and osteocalcin. Mesenchymal stromal cells seeded and cultured on porous three-dimensional selective laser melted nickel-titanium scaffolds homogeneously colonized the scaffold, and following osteogenic induction, filled the scaffold's pore volume with extracellular matrix. The combination of bone-related mechanical properties of selective laser melted nickel-titanium with its cytocompatibility and support of osteogenic differentiation of mesenchymal stromal cells highlights its potential as a superior bone substitute as compared to clinically used titanium. PMID:25383165

  5. Transport of iron oxide nanoparticles in saturated porous media: a large-scale 3D study

    NASA Astrophysics Data System (ADS)

    Velimirovic, Milica; Schmid, Doris; Micić, Vesna; Miyajima, Kumiko; Klaas, Norbert; Braun, Jürgen; Bosch, Julian; Meckenstock, Rainer; von der Kammer, Frank; Hofmann, Thilo

    2016-04-01

    Iron oxide nanoparticles (FeOxNp) have a high potential as electron acceptor for in situ microbial oxidation of a wide range of recalcitrant groundwater contaminants (Bosch et al., 2010). Tosco et al. (2012) reported on high colloidal stability of FeOxNp dispersed in water, their low deposition behavior, and consequently improved transport in column experiments compared to extensively studied zerovalent iron nanoparticles. However, determination of FeOxNp transport behavior at the field-relevant conditions has not been done before. The present work is aimed to evaluate different complementary methods for detection, quantification and transport characterization of FeOxNp in a large-scale three-dimensional (3D) model aquifer. Prior to that, batch-scale experiments were performed in order to elucidate the potential of the selected methods for direct and indirect characterization and detection of FeOxNp. Direct methods included measurements of particle size distribution, particle concentration, Fetot content and turbidity of the FeOxNp suspension. Indirect methods included measurements of particle zeta potential, as well as TOC content and pH of the FeOxNp suspension. The results of the batch experiments indicated that the most suitable approach for detecting and quantifying FeOxNp was measuring Fetot content and suspension turbidity, as well as particle size determined using dynamic light scattering principle. These complementary methods were further applied in a large-scale 3D study containing medium and coarse sand in order to 1) assess the transport of FeOxNp in saturated porous medium during injection (VFeOx = 6 m3, cparticle = 20 g/L, Qinj = 0.7 m3/h), and 2) illustrate their spatial distribution after injection. The outcomes of the large-scale 3D study confirmed that FeOxNp transport can be successfully investigated applying complementary methods. Monitoring data including Fetot content, turbidity and particle size showed the transport of particles towards the

  6. Development of nanocellulose scaffolds with tunable structures to support 3D cell culture.

    PubMed

    Liu, Jun; Cheng, Fang; Grénman, Henrik; Spoljaric, Steven; Seppälä, Jukka; E Eriksson, John; Willför, Stefan; Xu, Chunlin

    2016-09-01

    Swollen three-dimensional nanocellulose films and their resultant aerogels were prepared as scaffolds towards tissue engineering application. The nanocellulose hydrogels with various swelling degree (up to 500 times) and the resultant aerogels with desired porosity (porosity up to 99.7% and specific surface area up to 308m(2)/g) were prepared by tuning the nanocellulose charge density, the swelling media conditions, and the material processing approach. Representative cell-based assays were applied to assess the material biocompatibility and efficacy of the human extracellular matrix (ECM)-mimicking nanocellulose scaffolds. The effects of charge density and porosity of the scaffolds on the biological tests were investigated for the first time. The results reveal that the nanocellulose scaffolds could promote the survival and proliferation of tumor cells, and enhance the transfection of exogenous DNA into the cells. These results suggest the usefulness of the nanocellulose-based matrices in supporting crucial cellular processes during cell growth and proliferation. PMID:27185139

  7. 3D hybrid-porous carbon derived from carbonization of metal organic frameworks for high performance supercapacitors

    NASA Astrophysics Data System (ADS)

    Bao, Weizhai; Mondal, Anjon Kumar; Xu, Jing; Wang, Chengyin; Su, Dawei; Wang, Guoxiu

    2016-09-01

    We report a rational design and synthesis of 3D hybrid-porous carbon with a hierarchical pore architecture for high performance supercapacitors. It contains micropores (<2 nm diameter) and mesopores (2-4 nm), derived from carbonization of unique porous metal organic frameworks (MOFs). Owning to the synergistic effect of micropores and mesopores, the hybrid-porous carbon has exceptionally high ion-accessible surface area and low ion diffusion resistance, which is desired for supercapacitor applications. When applied as electrode materials in supercapacitors, 3D hybrid-porous carbon demonstrates a specific capacitance of 332 F g-1 at a constant charge/discharge current of 500 mA g-1. The supercapacitors can endure more than 10,000 cycles without degradation of capacitance.

  8. Ice-templated Self-assembly of VOPO4–Graphene Nanocomposites for Vertically Porous 3D Supercapacitor Electrodes

    PubMed Central

    Lee, Kwang Hoon; Lee, Young-Woo; Lee, Seung Woo; Ha, Jeong Sook; Lee, Sang-Soo; Son, Jeong Gon

    2015-01-01

    A simple ice-templated self-assembly process is used to prepare a three-dimensional (3D) and vertically porous nanocomposite of layered vanadium phosphates (VOPO4) and graphene nanosheets with high surface area and high electrical conductivity. The resulting 3D VOPO4–graphene nanocomposite has a much higher capacitance of 527.9 F g−1 at a current density of 0.5 A g−1, compared with ~247 F g−1 of simple 3D VOPO4, with solid cycling stability. The enhanced pseudocapacitive behavior mainly originates from vertically porous structures from directionally grown ice crystals and simultaneously inducing radial segregation and forming inter-stacked structures of VOPO4–graphene nanosheets. This VOPO4–graphene nanocomposite electrode exhibits high surface area, vertically porous structure to the separator, structural stability from interstacked structure and high electrical conductivity, which would provide the short diffusion paths of electrolyte ions and fast transportation of charges within the conductive frameworks. In addition, an asymmetric supercapacitor (ASC) is fabricated by using vertically porous VOPO4–graphene as the positive electrode and vertically porous 3D graphene as the negative electrode; it exhibits a wide cell voltage of 1.6 V and a largely enhanced energy density of 108 Wh kg−1. PMID:26333591

  9. Validation of an in vitro 3D bone culture model with perfused and mechanically stressed ceramic scaffold.

    PubMed

    Bouet, G; Cruel, M; Laurent, C; Vico, L; Malaval, L; Marchat, D

    2015-01-01

    An engineered three dimensional (3D) in vitro cell culture system was designed with the goal of inducing and controlling in vitro osteogenesis in a reproducible manner under conditions more similar to the in vivo bone microenvironment than traditional two-dimensional (2D) models. This bioreactor allows efficient mechanical loading and perfusion of an original cubic calcium phosphate bioceramic of highly controlled composition and structure. This bioceramic comprises an internal portion containing homogeneously interconnected macropores surrounded by a dense layer, which minimises fluid flow bypass around the scaffold. This dense and flat layer permits the application of a homogeneous loading on the bioceramic while also enhancing its mechanical strength. Numerical modelling of constraints shows that the system provides direct mechanical stimulation of cells within the scaffold. Experimental results establish that under perfusion at a steady flow of 2 µL/min, corresponding to 3 ≤ Medium velocity ≤ 23 µm/s, mouse calvarial cells grow and differentiate as osteoblasts in a reproducible manner, and lay down a mineralised matrix. Moreover, cells respond to mechanical loading by increasing C-fos expression, which demonstrates the effective mechanical stimulation of the culture within the scaffold. In summary, we provide a "proof-of-concept" for osteoblastic cell culture in a controlled 3D culture system under perfusion and mechanical loading. This model will be a tool to analyse bone cell functions in vivo, and will provide a bench testing system for the clinical assessment of bioactive bone-targeting molecules under load.

  10. The Use of Silk as a Scaffold for Mature, Sustainable Unilocular Adipose 3D Tissue Engineered Systems.

    PubMed

    Abbott, Rosalyn D; Wang, Rebecca Y; Reagan, Michaela R; Chen, Ying; Borowsky, Francis E; Zieba, Adam; Marra, Kacey G; Rubin, J Peter; Ghobrial, Irene M; Kaplan, David L

    2016-07-01

    There is a critical need for monitoring physiologically relevant, sustainable, human adipose tissues in vitro to gain new insights into metabolic diseases. To support long-term culture, a 3D silk scaffold assisted culture system is developed that maintains mature unilocular adipocytes ex vivo in coculture with preadipocytes, endothelial cells, and smooth muscle cells obtained from small volumes of liquefied adipose samples. Without the silk scaffold, adipose tissue explants cannot be sustained in long-term culture (3 months) due to their fragility. Adjustments to media components are used to tune lipid metabolism and proliferation, in addition to responsiveness to an inflammatory stimulus. Interestingly, patient specific responses to TNFα stimulation are observed, providing a proof-of-concept translational technique for patient specific disease modeling in the future. In summary, this novel 3D scaffold assisted approach is required for establishing physiologically relevant, sustainable, human adipose tissue systems from small volumes of lipoaspirate, making this methodology of great value to studies of metabolism, adipokine-driven diseases, and other diseases where the roles of adipocytes are only now becoming uncovered. PMID:27197588

  11. Strontium eluting graphene hybrid nanoparticles augment osteogenesis in a 3D tissue scaffold.

    PubMed

    Kumar, Sachin; Chatterjee, Kaushik

    2015-02-01

    The objective of this work was to prepare hybrid nanoparticles of graphene sheets decorated with strontium metallic nanoparticles and demonstrate their advantages in bone tissue engineering. Strontium-decorated reduced graphene oxide (RGO_Sr) hybrid nanoparticles were synthesized by the facile reduction of graphene oxide and strontium nitrate. X-ray diffraction, transmission electron microscopy, and atomic force microscopy revealed that the hybrid particles were composed of RGO sheets decorated with 200-300 nm metallic strontium particles. Thermal gravimetric analysis further confirmed the composition of the hybrid particles as 22 wt% of strontium. Macroporous tissue scaffolds were prepared by incorporating RGO_Sr particles in poly(ε-caprolactone) (PCL). The PCL/RGO_Sr scaffolds were found to elute strontium ions in aqueous medium. Osteoblast proliferation and differentiation was significantly higher in the PCL scaffolds containing the RGO_Sr particles in contrast to neat PCL and PCL/RGO scaffolds. The increased biological activity can be attributed to the release of strontium ions from the hybrid nanoparticles. This study demonstrates that composites prepared using hybrid nanoparticles that elute strontium ions can be used to prepare multifunctional scaffolds with good mechanical and osteoinductive properties. These findings have important implications for designing the next generation of biomaterials for use in tissue regeneration. PMID:25553731

  12. Strontium eluting graphene hybrid nanoparticles augment osteogenesis in a 3D tissue scaffold.

    PubMed

    Kumar, Sachin; Chatterjee, Kaushik

    2015-02-01

    The objective of this work was to prepare hybrid nanoparticles of graphene sheets decorated with strontium metallic nanoparticles and demonstrate their advantages in bone tissue engineering. Strontium-decorated reduced graphene oxide (RGO_Sr) hybrid nanoparticles were synthesized by the facile reduction of graphene oxide and strontium nitrate. X-ray diffraction, transmission electron microscopy, and atomic force microscopy revealed that the hybrid particles were composed of RGO sheets decorated with 200-300 nm metallic strontium particles. Thermal gravimetric analysis further confirmed the composition of the hybrid particles as 22 wt% of strontium. Macroporous tissue scaffolds were prepared by incorporating RGO_Sr particles in poly(ε-caprolactone) (PCL). The PCL/RGO_Sr scaffolds were found to elute strontium ions in aqueous medium. Osteoblast proliferation and differentiation was significantly higher in the PCL scaffolds containing the RGO_Sr particles in contrast to neat PCL and PCL/RGO scaffolds. The increased biological activity can be attributed to the release of strontium ions from the hybrid nanoparticles. This study demonstrates that composites prepared using hybrid nanoparticles that elute strontium ions can be used to prepare multifunctional scaffolds with good mechanical and osteoinductive properties. These findings have important implications for designing the next generation of biomaterials for use in tissue regeneration.

  13. High porous titanium scaffolds showed higher compatibility than lower porous beta-tricalcium phosphate scaffolds for regulating human osteoblast and osteoclast differentiation.

    PubMed

    Hirota, Makoto; Hayakawa, Tohru; Shima, Takaki; Ametani, Akihiro; Tohnai, Iwai

    2015-04-01

    We compared osteoblast and osteoclast differentiation when using beta-tricalcium phosphate (βTCP) and titanium scaffolds by investigating human mesenchymal stem cells (hMSCs) and osteoclast progenitor cell activities. hMSCs were cultured for 7, 14, and 21days on titanium scaffolds with 60%, 73%, and 87% porosity and on βTCP scaffolds with 60% and 75% porosity. Human osteoclast progenitor cells were cultured with osteoblast for 14 and 21days on 87% titanium and 75% βTCP scaffolds. Viable cell numbers with 60% and 73% titanium were higher than with 87% titanium and βTCP scaffolds (P<0.05). An 87% titanium scaffold resulted in the highest osteocalcin production with calcification on day 14 (P<0.01) in titanium scaffolds. All titanium scaffolds resulted in higher osteocalcin production on days 7 and 14 compared to βTCP scaffolds (P<0.01). Osteoblasts cultured on 87% titanium scaffolds suppressed osteoclast differentiation on day 7 but enhanced osteoclast differentiation on day 14 compared to 75% βTCP scaffolds (P<0.01). These findings concluded that high porosity titanium scaffolds could enhance progression of hMSC/osteoblast differentiation and regulated osteoclast differentiation cooperating with osteoblast differentiation for calcification as compared with lower porous βTCP.

  14. Photopatterning of hydrogel scaffolds coupled to filter materials using stereolithography for perfused 3D culture of hepatocytes.

    PubMed

    Neiman, Jaclyn A Shepard; Raman, Ritu; Chan, Vincent; Rhoads, Mary G; Raredon, Micha Sam B; Velazquez, Jeremy J; Dyer, Rachel L; Bashir, Rashid; Hammond, Paula T; Griffith, Linda G

    2015-04-01

    In vitro models that recapitulate the liver's structural and functional complexity could prolong hepatocellular viability and function to improve platforms for drug toxicity studies and understanding liver pathophysiology. Here, stereolithography (SLA) was employed to fabricate hydrogel scaffolds with open channels designed for post-seeding and perfused culture of primary hepatocytes that form 3D structures in a bioreactor. Photopolymerizable polyethylene glycol-based hydrogels were fabricated coupled to chemically activated, commercially available filters (polycarbonate and polyvinylidene fluoride) using a chemistry that permitted cell viability, and was robust enough to withstand perfused culture of up to 1 µL/s for at least 7 days. SLA energy dose, photoinitiator concentrations, and pretreatment conditions were screened to determine conditions that maximized cell viability and hydrogel bonding to the filter. Multiple open channel geometries were readily achieved, and included ellipses and rectangles. Rectangular open channels employed for subsequent studies had final dimensions on the order of 350 µm by 850 µm. Cell seeding densities and flow rates that promoted cell viability were determined. Perfused culture of primary hepatocytes in hydrogel scaffolds in the presence of soluble epidermal growth factor (EGF) prolonged the maintenance of albumin production throughout the 7-day culture relative to 2D controls. This technique of bonding hydrogel scaffolds can be employed to fabricate soft scaffolds for a number of bioreactor configurations and applications.

  15. Marrow-Derived Stem Cell Motility in 3D Synthetic Scaffold Is Governed by Geometry Along With Adhesivity and Stiffness

    PubMed Central

    Peyton, Shelly R.; Kalcioglu, Z. Ilke; Cohen, Joshua C.; Runkle, Anne P.; Van Vliet, Krystyn J.; Lauffenburger, Douglas A.

    2012-01-01

    Design of 3D scaffolds that can facilitate proper survival, proliferation, and differentiation of progenitor cells is a challenge for clinical applications involving large connective tissue defects. Cell migration within such scaffolds is a critical process governing tissue integration. Here, we examine effects of scaffold pore diameter, in concert with matrix stiffness and adhesivity, as independently tunable parameters that govern marrow-derived stem cell motility. We adopted an “inverse opal” processing technique to create synthetic scaffolds by crosslinking poly(ethylene glycol) at different densities (controlling matrix elastic moduli or stiffness) and small doses of a heterobifunctional monomer (controlling matrix adhesivity) around templating beads of different radii. As pore diameter was varied from 7 to 17 µm (i.e., from significantly smaller than the spherical cell diameter to approximately cell diameter), it displayed a profound effect on migration of these stem cells—including the degree to which motility was sensitive to changes in matrix stiffness and adhesivity. Surprisingly, the highest probability for substantive cell movement through pores was observed for an intermediate pore diameter, rather than the largest pore diameter, which exceeded cell diameter. The relationships between migration speed, displacement, and total path length were found to depend strongly on pore diameter. We attribute this dependence to convolution of pore diameter and void chamber diameter, yielding different geometric environments experienced by the cells within. PMID:21449030

  16. Synthesis of highly interconnected 3D scaffold from Arothron stellatus skin collagen for tissue engineering application.

    PubMed

    Ramanathan, Giriprasath; Singaravelu, Sivakumar; Raja, M D; Sivagnanam, Uma Tiruchirapalli

    2015-11-01

    The substrate which is avidly used for tissue engineering applications should have good mechanical and biocompatible properties, and all these parameters are often considered as essential for dermal reformation. Highly interconnected three dimensional (3D) wound dressing material with enhanced structural integrity was synthesized from Arothron stellatus fish skin (AsFS) collagen for tissue engineering applications. The synthesized 3D collagen sponge (COL-SPG) was further characterized by different physicochemical methods. The scanning electron microscopy analysis of the material demonstrated that well interconnected pores with homogeneous microstructure on the surface aids higher swelling index and that the material also possessed good mechanical properties with a Young's modulus of 0.89±0.2 MPa. Biocompatibility of the 3D COL-SPG showed 92% growth for both NIH 3T3 fibroblasts and keratinocytes. Overall, the study revealed that synthesized 3D COL-SPG from fish skin will act as a promising wound dressing in skin tissue engineering.

  17. Rapid prototyped porous nickel–titanium scaffolds as bone substitutes

    PubMed Central

    Hoffmann, Waldemar; Bormann, Therese; Rossi, Antonella; Müller, Bert; Schumacher, Ralf; Martin, Ivan; Wendt, David

    2014-01-01

    While calcium phosphate–based ceramics are currently the most widely used materials in bone repair, they generally lack tensile strength for initial load bearing. Bulk titanium is the gold standard of metallic implant materials, but does not match the mechanical properties of the surrounding bone, potentially leading to problems of fixation and bone resorption. As an alternative, nickel–titanium alloys possess a unique combination of mechanical properties including a relatively low elastic modulus, pseudoelasticity, and high damping capacity, matching the properties of bone better than any other metallic material. With the ultimate goal of fabricating porous implants for spinal, orthopedic and dental applications, nickel–titanium substrates were fabricated by means of selective laser melting. The response of human mesenchymal stromal cells to the nickel–titanium substrates was compared to mesenchymal stromal cells cultured on clinically used titanium. Selective laser melted titanium as well as surface-treated nickel–titanium and titanium served as controls. Mesenchymal stromal cells had similar proliferation rates when cultured on selective laser melted nickel–titanium, clinically used titanium, or controls. Osteogenic differentiation was similar for mesenchymal stromal cells cultured on the selected materials, as indicated by similar gene expression levels of bone sialoprotein and osteocalcin. Mesenchymal stromal cells seeded and cultured on porous three-dimensional selective laser melted nickel–titanium scaffolds homogeneously colonized the scaffold, and following osteogenic induction, filled the scaffold’s pore volume with extracellular matrix. The combination of bone-related mechanical properties of selective laser melted nickel–titanium with its cytocompatibility and support of osteogenic differentiation of mesenchymal stromal cells highlights its potential as a superior bone substitute as compared to clinically used titanium. PMID:25383165

  18. Osteogenic Differentiation of Human Mesenchymal Stem Cells in 3-D Zr-Si Organic-Inorganic Scaffolds Produced by Two-Photon Polymerization Technique

    PubMed Central

    Koroleva, Anastasia; Deiwick, Andrea; Nguyen, Alexander; Schlie-Wolter, Sabrina; Narayan, Roger; Timashev, Peter; Popov, Vladimir; Bagratashvili, Viktor; Chichkov, Boris

    2015-01-01

    Two-photon polymerization (2PP) is applied for the fabrication of 3-D Zr-Si scaffolds for bone tissue engineering. Zr-Si scaffolds with 150, 200, and 250 μm pore sizes are seeded with human bone marrow stem cells (hBMSCs) and human adipose tissue derived stem cells (hASCs) and cultured in osteoinductive and control media for three weeks. Osteogenic differentiation of hASCs and hBMSCs and formation of bone matrix is comparatively analyzed via alkaline phosphatase activity (ALP), calcium quantification, osteocalcin staining and scanning electron microscopy (SEM). It is observed that the 150 μm pore size Zr-Si scaffolds support the strongest matrix mineralization, as confirmed by calcium deposition. Analysis of ALP activity, osteocalcin staining and SEM observations of matrix mineralization reveal that mesenchymal stem cells cultured on 3-D scaffolds without osteogenic stimulation spontaneously differentiate towards osteogenic lineage. Nanoindentation measurements show that aging of the 2PP-produced Zr-Si scaffolds in aqueous or alcohol media results in an increase in the scaffold Young’s modulus and hardness. Moreover, accelerated formation of bone matrix by hASCs is noted, when cultured on the scaffolds with lower Young’s moduli and hardness values (non aged scaffolds) compared to the cells cultured on scaffolds with higher Young’s modulus and hardness values (aged scaffolds). Presented results support the potential application of Zr-Si scaffolds for autologous bone tissue engineering. PMID:25706270

  19. The influence of plasma technology coupled to chemical grafting on the cell growth compliance of 3D hydroxyapatite scaffolds.

    PubMed

    Russo, Laura; Zanini, Stefano; Giannoni, Paolo; Landi, Elena; Villa, Anna; Sandri, Monica; Riccardi, Claudia; Quarto, Rodolfo; Doglia, Silvia M; Nicotra, Francesco; Cipolla, Laura

    2012-11-01

    The development of advanced materials with biomimetic features in order to elicit desired biological responses and to guarantee tissue biocompatibility is recently gaining attention for tissue engineering applications. Bioceramics, such as hydroxyapatite-based biomaterials are now used in a number of different applications throughout the body, covering all areas of the skeleton, due to their biological and chemical similarity to the inorganic phases of bones. When bioactive sintered hydroxyapatite (HA) is desired, biomolecular modification of these materials is needed. In the present work, we investigated the influence of plasma surface modification coupled to chemical grafting on the cell growth compliance of HA 3D scaffolds.

  20. Carbon Quantum Dots and Their Derivative 3D Porous Carbon Frameworks for Sodium-Ion Batteries with Ultralong Cycle Life.

    PubMed

    Hou, Hongshuai; Banks, Craig E; Jing, Mingjun; Zhang, Yan; Ji, Xiaobo

    2015-12-16

    A new methodology for the synthesis of carbon quantum dots (CQDs) for large production is proposed. The as-obtained CQDs can be transformed into 3D porous carbon frameworks exhibiting superb sodium storage properties with ultralong cycle life and ultrahigh rate capability, comparable to state-of-the-art carbon anode materials for sodium-ion batteries.

  1. Differentiation capacity and maintenance of differentiated phenotypes of human mesenchymal stromal cells cultured on two distinct types of 3D polymeric scaffolds.

    PubMed

    Leferink, A M; Santos, D; Karperien, M; Truckenmüller, R K; van Blitterswijk, C A; Moroni, L

    2015-12-01

    Many studies have shown the influence of soluble factors and material properties on the differentiation capacity of mesenchymal stromal cells (MSCs) cultured as monolayers. These types of two-dimensional (2D) studies can be used as simplified models to understand cell processes related to stem cell sensing and mechano-transduction in a three-dimensional (3D) context. For several other mechanisms such as cell-cell signaling, cell proliferation and cell morphology, it is well-known that cells behave differently on a planar surface compared to cells in 3D environments. In classical tissue engineering approaches, a combination of cells, 3D scaffolds and soluble factors are considered as the key ingredients for the generation of mechanically stable 3D tissue constructs. However, when MSCs are used for tissue engineering strategies, little is known about the maintenance of their differentiation potential in 3D scaffolds after the removal of differentiation soluble factors. In this study, the differentiation potential of human MSCs (hMSCs) into the chondrogenic and osteogenic lineages on two distinct 3D scaffolds, additive manufactured electrospun scaffolds, was assessed and compared to conventional 2D culture. Human MSCs cultured in the presence of soluble factors in 3D showed to differentiate to the same extent as hMSCs cultured as 2D monolayers or as scaffold-free pellets, indicating that the two scaffolds do not play a consistent role in the differentiation process. In the case of phenotypic changes, the achieved differentiated phenotype was not maintained after the removal of soluble factors, suggesting that the plasticity of hMSCs is retained in 3D cell culture systems. This finding can have implications for future tissue engineering approaches in which the validation of hMSC differentiation on 3D scaffolds will not be sufficient to ensure the maintenance of the functionality of the cells in the absence of appropriate differentiation signals. PMID:26566169

  2. Novel porous gelatin scaffolds by overrun/particle leaching process for tissue engineering applications.

    PubMed

    Kang, Hyun Goo; Kim, So Yeon; Lee, Young Moo

    2006-11-01

    Porous gelatin scaffolds were prepared using a modified overrun process, which is a novel method for preparing a porous matrix by injecting air and mixing polymer solution at low temperature. The pores in the scaffolds formed by the overrun process exhibited a dual-pore structure due to the injection of air bubbles and ice recrystallization. However, the morphology of the overrun-processed gelatin scaffolds had closed pore structures. The closed pore structure was reformed into a uniformly distributed and interconnected open structure by the combination of the overrun process and a particle-leaching technique (NaCl and sucrose). The mechanical strength and biodegradation rate of gelatin scaffolds were controlled by the matrix porosity and concentration of gelatin solution. Despite higher porosity, overrun processed gelatin scaffolds showed similar mechanical strength to freeze-dried scaffolds. After 1 week of in vitro culturing, the fibroblasts in overrun-processed scaffolds were widely distributed on the surface of the scaffold pores, whereas cells seeded in freeze-dried scaffolds were mainly placed on the top and bottom of the scaffolds. Therefore, the overrun process combined with a particle-leaching technique can be applied to fabricate porous scaffolds with a desirable cellular structure for tissue engineering applications.

  3. Porous Structures in Stacked, Crumpled and Pillared Graphene-Based 3D Materials

    PubMed Central

    Guo, Fei; Creighton, Megan; Chen, Yantao; Hurt, Robert; Külaots, Indrek

    2015-01-01

    Graphene, an atomically thin material with the theoretical surface area of 2600 m2g−1, has great potential in the fields of catalysis, separation, and gas storage if properly assembled into functional 3D materials at large scale. In ideal non-interacting ensembles of non-porous multilayer graphene plates, the surface area can be adequately estimated using the simple geometric law ~ 2600 m2g−1/N, where N is the number of graphene sheets per plate. Some processing operations, however, lead to secondary plate-plate stacking, folding, crumpling or pillaring, which give rise to more complex structures. Here we show that bulk samples of multilayer graphene plates stack in an irregular fashion that preserves the 2600/N surface area and creates regular slot-like pores with sizes that are multiples of the unit plate thickness. In contrast, graphene oxide deposits into films with massive area loss (2600 to 40 m2g−1) due to nearly perfect alignment and stacking during the drying process. Pillaring graphene oxide sheets by co-deposition of colloidal-phase particle-based spacers has the potential to partially restore the large monolayer surface. Surface areas as high as 1000 m2g−1 are demonstrated here through colloidal-phase deposition of graphene oxide with water-dispersible aryl-sulfonated ultrafine carbon black as a pillaring agent. PMID:26478597

  4. Cation Exchange in Dynamic 3D Porous Magnets: Improvement of the Physical Properties.

    PubMed

    Grancha, Thais; Acosta, Alvaro; Cano, Joan; Ferrando-Soria, Jesús; Seoane, Beatriz; Gascon, Jorge; Pasán, Jorge; Armentano, Donatella; Pardo, Emilio

    2015-11-16

    We report two novel three-dimensional porous coordination polymers (PCPs) of formulas Li4{Mn4[Cu2(Me3mpba)2]3}·68H2O (2) and K4{Mn4[Cu2(Me3mpba)2]3}·69H2O (3) obtained-via alkali cation exchange in a single-crystal to single-crystal process-from the earlier reported anionic manganese(II)-copper(II) PCP of formula Na4{Mn4[Cu2(Me3mpba)2]3}·60H2O (1) [Me3mpba(4-) = N,N'-2,4,6-trimethyl-1,3-phenylenebis(oxamate)]. This postsynthetic process succeeds where the direct synthesis in solution from the corresponding building blocks fails and affords significantly more robust PCPs with enhanced magnetic properties [long-range 3D magnetic ordering temperatures for the dehydrated phases (1'-3') of 2.0 (1'), 12.0 (2'), and 20.0 K (3')]. Changes in the adsorptive properties upon postsynthetic exchange suggest that the nature, electrostatic properties, mobility, and location of the cations within the framework are crucial for the enhanced structural stability. Overall, these results further confirm the potential of postsynthetic methods (including cation exchange) to obtain PCPs with novel or enhanced physical properties while maintaining unaltered their open-framework structures. PMID:26492551

  5. Cation Exchange in Dynamic 3D Porous Magnets: Improvement of the Physical Properties.

    PubMed

    Grancha, Thais; Acosta, Alvaro; Cano, Joan; Ferrando-Soria, Jesús; Seoane, Beatriz; Gascon, Jorge; Pasán, Jorge; Armentano, Donatella; Pardo, Emilio

    2015-11-16

    We report two novel three-dimensional porous coordination polymers (PCPs) of formulas Li4{Mn4[Cu2(Me3mpba)2]3}·68H2O (2) and K4{Mn4[Cu2(Me3mpba)2]3}·69H2O (3) obtained-via alkali cation exchange in a single-crystal to single-crystal process-from the earlier reported anionic manganese(II)-copper(II) PCP of formula Na4{Mn4[Cu2(Me3mpba)2]3}·60H2O (1) [Me3mpba(4-) = N,N'-2,4,6-trimethyl-1,3-phenylenebis(oxamate)]. This postsynthetic process succeeds where the direct synthesis in solution from the corresponding building blocks fails and affords significantly more robust PCPs with enhanced magnetic properties [long-range 3D magnetic ordering temperatures for the dehydrated phases (1'-3') of 2.0 (1'), 12.0 (2'), and 20.0 K (3')]. Changes in the adsorptive properties upon postsynthetic exchange suggest that the nature, electrostatic properties, mobility, and location of the cations within the framework are crucial for the enhanced structural stability. Overall, these results further confirm the potential of postsynthetic methods (including cation exchange) to obtain PCPs with novel or enhanced physical properties while maintaining unaltered their open-framework structures.

  6. 3D cell culture and osteogenic differentiation of human bone marrow stromal cells plated onto jet-sprayed or electrospun micro-fiber scaffolds.

    PubMed

    Brennan, Meadhbh Á; Renaud, Audrey; Gamblin, Anne-Laure; D'Arros, Cyril; Nedellec, Steven; Trichet, Valerie; Layrolle, Pierre

    2015-08-01

    A major limitation of the 2D culture systems is that they fail to recapitulate the in vivo 3D cellular microenvironment whereby cell-cell and cell-extracellular matrix (ECM) interactions occur. In this paper, a biomaterial scaffold that mimics the structure of collagen fibers was produced by jet-spraying. This micro-fiber polycaprolactone (PCL) scaffold was evaluated for 3D culture of human bone marrow mesenchymal stromal cells (MSCs) in comparison with a commercially available electrospun scaffold. The jet-sprayed scaffolds had larger pore diameters, greater porosity, smaller diameter fibers, and more heterogeneous fiber diameter size distribution compared to the electrospun scaffolds. Cells on jet-sprayed constructs exhibited spread morphology with abundant cytoskeleton staining, whereas MSCs on electrospun scaffolds appeared less extended with fewer actin filaments. MSC proliferation and cell infiltration occurred at a faster rate on jet-sprayed compared to electrospun scaffolds. Osteogenic differentiation of MSCs and ECM production as measured by ALP, collagen and calcium deposition was superior on jet-sprayed compared to electrospun scaffolds. The jet-sprayed scaffold which mimics the native ECM and permits homogeneous cell infiltration is important for 3D in vitro applications such as bone cellular interaction studies or drug testing, as well as bone tissue engineering strategies. PMID:26238732

  7. DCM3D: A dual-continuum, three-dimensional, ground-water flow code for unsaturated, fractured, porous media

    SciTech Connect

    Updegraff, C.D. ); Lee, C.E. ); Gallegos, D.P. )

    1991-02-01

    This report constitutes the user's manual for DCM3D. DCM3D is a computer code for solving three-dimensional, ground-water flow problems in variably saturated, fractured porous media. The code is based on a dual-continuum model with porous media comprising one continuum and fractures comprising the other. The continua are connected by a transfer term that depends on the unsaturated permeability of the porous medium. An integrated finite-difference scheme is used to discretize the governing equations in space. The time-dependent term is allowed to remain continuous. The resulting set of ordinary differential equations (ODE's) is solved with a general ODE solver, LSODES. The code is capable of handling transient, spatially dependent source terms and boundary conditions. The boundary conditions can either prescribed head or prescribed flux. 24 refs., 22 figs., 5 tabs.

  8. Instant gelation synthesis of 3D porous MoS2@C nanocomposites for lithium ion batteries.

    PubMed

    Fei, Ling; Xu, Yun; Wu, Xiaofei; Chen, Gen; Li, Yuling; Li, Binsong; Deng, Shuguang; Smirnov, Sergei; Fan, Hongyou; Luo, Hongmei

    2014-04-01

    Three-dimensional (3D) nanoporous architectures, possessing high surface area, massive pores, and excellent structural stability, are highly desirable for many applications including catalysts and electrode materials in lithium ion batteries. However, the preparation of such materials remains a major challenge. Here, we introduce a novel method, instant gelation, for the synthesis of such materials. The as-prepared porous 3D MoS2@C nanocomposites, with layered MoS2 clusters or strips ingrained in porous and conductive 3D carbon matrix, indeed showed excellent electrochemical performance when applied as anode materials for lithium ion batteries. Its interconnected carbon network ensures good conductivity and fast electron transport; the micro-, and mesoporous nature effectively shortens the lithium ion diffusion path and provides room necessary for volume expansion. The large specific surface area is beneficial for a better contact between electrode materials and electrolyte.

  9. Gelatin-layered and multi-sized porous β-tricalcium phosphate for tissue engineering scaffold

    PubMed Central

    2012-01-01

    The multi-sized porous β-tricalcium phosphate scaffolds were fabricated by freeze drying followed by slurry coating using a multi-sized porous sponge as a template. Then, gelatin was dip coated on the multi-sized porous β-tricalcium phosphate scaffolds under vacuum. The mechanical and biological properties of the fabricated scaffolds were evaluated and compared to the uniformly sized porous scaffolds and scaffolds that were not coated by gelatin. The compressive strength was tested by a universal testing machine, and the cell viability and differentiation behavior were measured using a cell counting kit and alkaline phosphatase activity using the MC3T3-E1 cells. In comparison, the gelatin-coated multi-sized porous β-tricalcium phosphate scaffold showed enhanced compressive strength. After 14 days, the multi-sized pores were shown to affect cell differentiation, and gelatin coatings were shown to affect the cell viability and differentiation. The results of this study demonstrated that the multi-sized porous β-tricalcium phosphate scaffold coated by gelatin enhanced the mechanical and biological strengths. PMID:22252276

  10. Design and Fabrication of 3D printed Scaffolds with a Mechanical Strength Comparable to Cortical Bone to Repair Large Bone Defects

    PubMed Central

    Roohani-Esfahani, Seyed-Iman; Newman, Peter; Zreiqat, Hala

    2016-01-01

    A challenge in regenerating large bone defects under load is to create scaffolds with large and interconnected pores while providing a compressive strength comparable to cortical bone (100–150 MPa). Here we design a novel hexagonal architecture for a glass-ceramic scaffold to fabricate an anisotropic, highly porous three dimensional scaffolds with a compressive strength of 110 MPa. Scaffolds with hexagonal design demonstrated a high fatigue resistance (1,000,000 cycles at 1–10 MPa compressive cyclic load), failure reliability and flexural strength (30 MPa) compared with those for conventional architecture. The obtained strength is 150 times greater than values reported for polymeric and composite scaffolds and 5 times greater than reported values for ceramic and glass scaffolds at similar porosity. These scaffolds open avenues for treatment of load bearing bone defects in orthopaedic, dental and maxillofacial applications. PMID:26782020

  11. Design and Fabrication of 3D printed Scaffolds with a Mechanical Strength Comparable to Cortical Bone to Repair Large Bone Defects.

    PubMed

    Roohani-Esfahani, Seyed-Iman; Newman, Peter; Zreiqat, Hala

    2016-01-01

    A challenge in regenerating large bone defects under load is to create scaffolds with large and interconnected pores while providing a compressive strength comparable to cortical bone (100-150 MPa). Here we design a novel hexagonal architecture for a glass-ceramic scaffold to fabricate an anisotropic, highly porous three dimensional scaffolds with a compressive strength of 110 MPa. Scaffolds with hexagonal design demonstrated a high fatigue resistance (1,000,000 cycles at 1-10 MPa compressive cyclic load), failure reliability and flexural strength (30 MPa) compared with those for conventional architecture. The obtained strength is 150 times greater than values reported for polymeric and composite scaffolds and 5 times greater than reported values for ceramic and glass scaffolds at similar porosity. These scaffolds open avenues for treatment of load bearing bone defects in orthopaedic, dental and maxillofacial applications.

  12. Design and Fabrication of 3D printed Scaffolds with a Mechanical Strength Comparable to Cortical Bone to Repair Large Bone Defects

    NASA Astrophysics Data System (ADS)

    Roohani-Esfahani, Seyed-Iman; Newman, Peter; Zreiqat, Hala

    2016-01-01

    A challenge in regenerating large bone defects under load is to create scaffolds with large and interconnected pores while providing a compressive strength comparable to cortical bone (100-150 MPa). Here we design a novel hexagonal architecture for a glass-ceramic scaffold to fabricate an anisotropic, highly porous three dimensional scaffolds with a compressive strength of 110 MPa. Scaffolds with hexagonal design demonstrated a high fatigue resistance (1,000,000 cycles at 1-10 MPa compressive cyclic load), failure reliability and flexural strength (30 MPa) compared with those for conventional architecture. The obtained strength is 150 times greater than values reported for polymeric and composite scaffolds and 5 times greater than reported values for ceramic and glass scaffolds at similar porosity. These scaffolds open avenues for treatment of load bearing bone defects in orthopaedic, dental and maxillofacial applications.

  13. Rapid and low-cost prototyping of 3D nanostructures with multi-layer hydrogen silsesquioxane scaffolds.

    PubMed

    Varghese, Leo T; Fan, Li; Wang, Jian; Xuan, Yi; Qi, Minghao

    2013-12-20

    A layer-by-layer (LBL) method can generate or approximate any three-dimensional (3D) structure, and has been the approach for the manufacturing of complementary metal-oxide-semiconductor (CMOS) devices. However, its high cost precludes the fabrication of anything other than CMOS-compatible devices, and general 3D nanostructures have been difficult to prototype in academia and small businesses, due to the lack of expensive facility and state-of-the-art tools. It is proposed and demonstrated that a novel process that can rapidly fabricate high-resolution three-dimensional (3D) nanostructures at low cost, without requiring specialized equipment. An individual layer is realized through electron-beam lithography patterning of hydrogen silsesquioxane (HSQ) resist, followed by planarization via spinning SU-8 resist and etch-back. A 4-layer silicon inverse woodpile photonic crystal with a period of 650 nm and a 7-layer HSQ scaffold with a period of 300 nm are demonstrated. This process provides a versatile and accessible solution to the fabrication of highly complex 3D nanostructures.

  14. Editorial on the original article entitled "3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration" published in the Biomaterials on February 14, 2014.

    PubMed

    Li, Lan; Jiang, Qing

    2015-05-01

    The paper entitled "3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration" published in the Biomaterials recently illuminated the way to make particular scaffolds with calcium phosphate (CaP) powder, phosphoric acid, type I collagen and Tween 80 in low temperature. After the optimal concentration of each component was determined, the scaffolds were evaluated in a critically sized murine femoral defect model and exhibited good material properties. We made some related introduction of materials applied in 3D printing for bone tissue engineering based on this article to demonstrate the current progress in this field of study.

  15. Editorial on the original article entitled “3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration” published in the Biomaterials on February 14, 2014

    PubMed Central

    Li, Lan

    2015-01-01

    The paper entitled “3D printing of composite calcium phosphate and collagen scaffolds for bone regeneration” published in the Biomaterials recently illuminated the way to make particular scaffolds with calcium phosphate (CaP) powder, phosphoric acid, type I collagen and Tween 80 in low temperature. After the optimal concentration of each component was determined, the scaffolds were evaluated in a critically sized murine femoral defect model and exhibited good material properties. We made some related introduction of materials applied in 3D printing for bone tissue engineering based on this article to demonstrate the current progress in this field of study. PMID:26046065

  16. Porous alumina scaffold produced by sol-gel combined polymeric sponge method

    NASA Astrophysics Data System (ADS)

    Hasmaliza, M.; Fazliah, M. N.; Shafinaz, R. J.

    2012-09-01

    Sol gel is a novel method used to produce high purity alumina with nanometric scale. In this study, three-dimensional porous alumina scaffold was produced using sol-gel polymeric sponge method. Briefly, sol gel alumina was prepared by evaporation and polymeric sponge cut to designated sizes were immersed in the sol gel followed by sintering at 1250 and 1550°C. In order to study the cell interaction, the porous alumina scaffold was sterilized using autoclave prior to Human Mesenchymal Stem Cells (HMSCs) seeding on the scaffold and the cell proliferation was assessed by alamarBlue® assay. SEM results showed that during the 21 day period, HMSCs were able to attach on the scaffold surface and the interconnecting pores while maintaining its proliferation. These findings suggested the potential use of the porous alumina produced as a scaffold for implantation procedure.

  17. Solute Transport in Cyclically Deformed Porous Tissue Scaffolds with Controlled Pore Cross-Sectional Geometries

    PubMed Central

    Op Den Buijs, Jorn; Lu, Lichun; Jorgensen, Steven M.; Dragomir-Daescu, Dan; Yaszemski, Michael J.

    2009-01-01

    The objective of this study was to investigate the influence of pore geometry on the transport rate and depth after repetitive mechanical deformation of porous scaffolds for tissue engineering applications. Flexible cubic imaging phantoms with pores in the shape of a circular cylinder, elliptic cylinder, and spheroid were fabricated from a biodegradable polymer blend using a combined 3D printing and injection molding technique. The specimens were immersed in fluid and loaded with a solution of a radiopaque solute. The solute distribution was quantified by recording 20 μm pixel-resolution images in an X-ray microimaging scanner at selected time points after intervals of dynamic straining with a mean strain of 8.6 ± 1.6% at 1.0 Hz. The results show that application of cyclic strain significantly increases the rate and depth of solute transport, as compared to diffusive transport alone, for all pore shapes. In addition, pore shape, pore size, and the orientation of the pore cross-sectional asymmetry with respect to the direction of strain greatly influence solute transport. Thus, pore geometry can be tailored to increase transport rates and depths in cyclically deformed scaffolds, which is of utmost importance when thick, metabolically functional tissues are to be engineered. PMID:19196145

  18. Nanofiber Yarn/Hydrogel Core-Shell Scaffolds Mimicking Native Skeletal Muscle Tissue for Guiding 3D Myoblast Alignment, Elongation, and Differentiation.

    PubMed

    Wang, Ling; Wu, Yaobin; Guo, Baolin; Ma, Peter X

    2015-09-22

    Designing scaffolds that can mimic native skeletal muscle tissue and induce 3D cellular alignment and elongated myotube formation remains an ongoing challenge for skeletal muscle tissue engineering. Herein, we present a simple technique to generate core-shell composite scaffolds for mimicking native skeletal muscle structure, which comprise the aligned nanofiber yarn (NFY) core and the photocurable hydrogel shell. The aligned NFYs are prepared by the hybrid composition including poly(caprolactone), silk fibroin, and polyaniline via a developed dry-wet electrospinning method. A series of core-shell column and sheet composite scaffolds are ultimately obtained by encapsulating a piece and layers of aligned NFY cores within the hydrogel shell after photo-cross-linking. C2C12 myoblasts are seeded within the core-shell scaffolds, and the good biocompatibility of these scaffolds and their ability to induce 3D cellular alignment and elongation are successfully demonstrated. Furthermore, the 3D elongated myotube formation within core-shell scaffolds is also performed after long-term cultivation. These data suggest that these core-shell scaffolds combine the aligned NFY core that guides the myoblast alignment and differentiation and the hydrogel shell that provides a suitable 3D environment for nutrition exchange and mechanical protection to perform a great practical application for skeletal muscle regeneration.

  19. Towards the Design of 3D Fiber-Deposited Poly(ε-caprolactone)/lron-Doped Hydroxyapatite Nanocomposite Magnetic Scaffolds for Bone Regeneration.

    PubMed

    De Santis, Roberta; Russo, Alessandro; Gloria, Antonio; D'Amora, Ugo; Russo, Teresa; Panseri, Silvia; Sandri, Monica; Tampieri, Anna; Marcacci, Maurilio; Dediu, Valentin A; Wilde, Colin J; Ambrosio, Luigi

    2015-07-01

    In the past few years, researchers have focused on the design and development of three-dimensional (3D) advanced scaffolds, which offer significant advantages in terms of cell performance. The introduction of magnetic features into scaffold technology could offer innovative opportunities to control cell populations within 3D microenvironments, with the potential to enhance their use in tissue regeneration or in cell-based analysis. In the present study, 3D fully biodegradable and magnetic nanocomposite scaffolds for bone tissue engineering, consisting of a poly(ε-caprolactone) (PCL) matrix reinforced with iron-doped hydroxyapatite (FeHA) nanoparticles, were designed and manufactured using a rapid prototyping technique. The performances of these novel 3D PCL/FeHA scaffolds were assessed through a combination of theoretical evaluation, experimental in vitro analyses and in vivo testing in a rabbit animal model. The results from mechanical com- pression tests were consistent with FEM simulations. The in vitro results showed that the cell growth in the magnetized scaffolds was 2.2-fold greater than that in non-magnetized ones. In vivo experiments further suggested that, after only 4 weeks, the PCL/FeHA scaffolds were completely filled with newly formed bone, proving a good level of histocompatibility. All of the results suggest that the introduction of magnetic features into biocompatible materials may confer significant advantages in terms of 3D cell assembly. PMID:26307846

  20. An open source image processing method to quantitatively assess tissue growth after non-invasive magnetic resonance imaging in human bone marrow stromal cell seeded 3D polymeric scaffolds.

    PubMed

    Leferink, Anne M; Fratila, Raluca M; Koenrades, Maaike A; van Blitterswijk, Clemens A; Velders, Aldrik; Moroni, Lorenzo

    2014-01-01

    Monitoring extracellular matrix (ECM) components is one of the key methods used to determine tissue quality in three-dimensional (3D) scaffolds for regenerative medicine and clinical purposes. This is even more important when multipotent human bone marrow stromal cells (hMSCs) are used, as it could offer a method to understand in real time the dynamics of stromal cell differentiation and eventually steer it into the desired lineage. Magnetic Resonance Imaging (MRI) is a promising tool to overcome the challenge of a limited transparency in opaque 3D scaffolds. Technical limitations of MRI involve non-uniform background intensity leading to fluctuating background signals and therewith complicating quantifications on the retrieved images. We present a post-imaging processing sequence that is able to correct for this non-uniform background intensity. To test the processing sequence we investigated the use of MRI for in vitro monitoring of tissue growth in three-dimensional poly(ethylene oxide terephthalate)-poly(butylene terephthalate) (PEOT/PBT) scaffolds. Results showed that MRI, without the need to use contrast agents, is a promising non-invasive tool to quantitatively monitor ECM production and cell distribution during in vitro culture in 3D porous tissue engineered constructs. PMID:25502022

  1. An Open Source Image Processing Method to Quantitatively Assess Tissue Growth after Non-Invasive Magnetic Resonance Imaging in Human Bone Marrow Stromal Cell Seeded 3D Polymeric Scaffolds

    PubMed Central

    Leferink, Anne M.; Fratila, Raluca M.; Koenrades, Maaike A.; van Blitterswijk, Clemens A.; Velders, Aldrik; Moroni, Lorenzo

    2014-01-01

    Monitoring extracellular matrix (ECM) components is one of the key methods used to determine tissue quality in three-dimensional (3D) scaffolds for regenerative medicine and clinical purposes. This is even more important when multipotent human bone marrow stromal cells (hMSCs) are used, as it could offer a method to understand in real time the dynamics of stromal cell differentiation and eventually steer it into the desired lineage. Magnetic Resonance Imaging (MRI) is a promising tool to overcome the challenge of a limited transparency in opaque 3D scaffolds. Technical limitations of MRI involve non-uniform background intensity leading to fluctuating background signals and therewith complicating quantifications on the retrieved images. We present a post-imaging processing sequence that is able to correct for this non-uniform background intensity. To test the processing sequence we investigated the use of MRI for in vitro monitoring of tissue growth in three-dimensional poly(ethylene oxide terephthalate)–poly(butylene terephthalate) (PEOT/PBT) scaffolds. Results showed that MRI, without the need to use contrast agents, is a promising non-invasive tool to quantitatively monitor ECM production and cell distribution during in vitro culture in 3D porous tissue engineered constructs. PMID:25502022

  2. Unimpeded permeation of water through biocidal graphene oxide sheets anchored on to 3D porous polyolefinic membranes

    NASA Astrophysics Data System (ADS)

    Mural, Prasanna Kumar S.; Jain, Shubham; Kumar, Sachin; Madras, Giridhar; Bose, Suryasarathi

    2016-04-01

    3D porous membranes were developed by etching one of the phases (here PEO, polyethylene oxide) from melt-mixed PE/PEO binary blends. Herein, we have systematically discussed the development of these membranes using X-ray micro-computed tomography. The 3D tomograms of the extruded strands and hot-pressed samples revealed a clear picture as to how the morphology develops and coarsens over a function of time during post-processing operations like compression molding. The coarsening of PE/PEO blends was traced using X-ray micro-computed tomography and scanning electron microscopy (SEM) of annealed blends at different times. It is now understood from X-ray micro-computed tomography that by the addition of a compatibilizer (here lightly maleated PE), a stable morphology can be visualized in 3D. In order to anchor biocidal graphene oxide sheets onto these 3D porous membranes, the PE membranes were chemically modified with acid/ethylene diamine treatment to anchor the GO sheets which were further confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and surface Raman mapping. The transport properties through the membrane clearly reveal unimpeded permeation of water which suggests that anchoring GO on to the membranes does not clog the pores. Antibacterial studies through the direct contact of bacteria with GO anchored PE membranes resulted in 99% of bacterial inactivation. The possible bacterial inactivation through physical disruption of the bacterial cell wall and/or reactive oxygen species (ROS) is discussed herein. Thus this study opens new avenues in designing polyolefin based antibacterial 3D porous membranes for water purification.3D porous membranes were developed by etching one of the phases (here PEO, polyethylene oxide) from melt-mixed PE/PEO binary blends. Herein, we have systematically discussed the development of these membranes using X-ray micro-computed tomography. The 3D tomograms of the extruded strands and

  3. Structure, Properties, and In Vitro Behavior of Heat-Treated Calcium Sulfate Scaffolds Fabricated by 3D Printing.

    PubMed

    Asadi-Eydivand, Mitra; Solati-Hashjin, Mehran; Shafiei, Seyedeh Sara; Mohammadi, Sepideh; Hafezi, Masoud; Abu Osman, Noor Azuan

    2016-01-01

    The ability of inkjet-based 3D printing (3DP) to fabricate biocompatible ceramics has made it one of the most favorable techniques to generate bone tissue engineering (BTE) scaffolds. Calcium sulfates exhibit various beneficial characteristics, and they can be used as a promising biomaterial in BTE. However, low mechanical performance caused by the brittle character of ceramic materials is the main weakness of 3DP calcium sulfate scaffolds. Moreover, the presence of certain organic matters in the starting powder and binder solution causes products to have high toxicity levels. A post-processing treatment is usually employed to improve the physical, chemical, and biological behaviors of the printed scaffolds. In this study, the effects of heat treatment on the structural, mechanical, and physical characteristics of 3DP calcium sulfate prototypes were investigated. Different microscopy and spectroscopy methods were employed to characterize the printed prototypes. The in vitro cytotoxicity of the specimens was also evaluated before and after heat treatment. Results showed that the as-printed scaffolds and specimens heat treated at 300°C exhibited severe toxicity in vitro but had almost adequate strength. By contrast, the specimens heat treated in the 500°C-1000°C temperature range, although non-toxic, had insufficient mechanical strength, which was mainly attributed to the exit of the organic binder before 500°C and the absence of sufficient densification below 1000°C. The sintering process was accelerated at temperatures higher than 1000°C, resulting in higher compressive strength and less cytotoxicity. An anhydrous form of calcium sulfate was the only crystalline phase existing in the samples heated at 500°C-1150°C. The formation of calcium oxide caused by partial decomposition of calcium sulfate was observed in the specimens heat treated at temperatures higher than 1200°C. Although considerable improvements in cell viability of heat-treated scaffolds were

  4. Structure, Properties, and In Vitro Behavior of Heat-Treated Calcium Sulfate Scaffolds Fabricated by 3D Printing.

    PubMed

    Asadi-Eydivand, Mitra; Solati-Hashjin, Mehran; Shafiei, Seyedeh Sara; Mohammadi, Sepideh; Hafezi, Masoud; Abu Osman, Noor Azuan

    2016-01-01

    The ability of inkjet-based 3D printing (3DP) to fabricate biocompatible ceramics has made it one of the most favorable techniques to generate bone tissue engineering (BTE) scaffolds. Calcium sulfates exhibit various beneficial characteristics, and they can be used as a promising biomaterial in BTE. However, low mechanical performance caused by the brittle character of ceramic materials is the main weakness of 3DP calcium sulfate scaffolds. Moreover, the presence of certain organic matters in the starting powder and binder solution causes products to have high toxicity levels. A post-processing treatment is usually employed to improve the physical, chemical, and biological behaviors of the printed scaffolds. In this study, the effects of heat treatment on the structural, mechanical, and physical characteristics of 3DP calcium sulfate prototypes were investigated. Different microscopy and spectroscopy methods were employed to characterize the printed prototypes. The in vitro cytotoxicity of the specimens was also evaluated before and after heat treatment. Results showed that the as-printed scaffolds and specimens heat treated at 300°C exhibited severe toxicity in vitro but had almost adequate strength. By contrast, the specimens heat treated in the 500°C-1000°C temperature range, although non-toxic, had insufficient mechanical strength, which was mainly attributed to the exit of the organic binder before 500°C and the absence of sufficient densification below 1000°C. The sintering process was accelerated at temperatures higher than 1000°C, resulting in higher compressive strength and less cytotoxicity. An anhydrous form of calcium sulfate was the only crystalline phase existing in the samples heated at 500°C-1150°C. The formation of calcium oxide caused by partial decomposition of calcium sulfate was observed in the specimens heat treated at temperatures higher than 1200°C. Although considerable improvements in cell viability of heat-treated scaffolds were

  5. Structure, Properties, and In Vitro Behavior of Heat-Treated Calcium Sulfate Scaffolds Fabricated by 3D Printing

    PubMed Central

    Asadi-Eydivand, Mitra; Solati-Hashjin, Mehran; Shafiei, Seyedeh Sara; Mohammadi, Sepideh; Hafezi, Masoud; Abu Osman, Noor Azuan

    2016-01-01

    The ability of inkjet-based 3D printing (3DP) to fabricate biocompatible ceramics has made it one of the most favorable techniques to generate bone tissue engineering (BTE) scaffolds. Calcium sulfates exhibit various beneficial characteristics, and they can be used as a promising biomaterial in BTE. However, low mechanical performance caused by the brittle character of ceramic materials is the main weakness of 3DP calcium sulfate scaffolds. Moreover, the presence of certain organic matters in the starting powder and binder solution causes products to have high toxicity levels. A post-processing treatment is usually employed to improve the physical, chemical, and biological behaviors of the printed scaffolds. In this study, the effects of heat treatment on the structural, mechanical, and physical characteristics of 3DP calcium sulfate prototypes were investigated. Different microscopy and spectroscopy methods were employed to characterize the printed prototypes. The in vitro cytotoxicity of the specimens was also evaluated before and after heat treatment. Results showed that the as-printed scaffolds and specimens heat treated at 300°C exhibited severe toxicity in vitro but had almost adequate strength. By contrast, the specimens heat treated in the 500°C–1000°C temperature range, although non-toxic, had insufficient mechanical strength, which was mainly attributed to the exit of the organic binder before 500°C and the absence of sufficient densification below 1000°C. The sintering process was accelerated at temperatures higher than 1000°C, resulting in higher compressive strength and less cytotoxicity. An anhydrous form of calcium sulfate was the only crystalline phase existing in the samples heated at 500°C–1150°C. The formation of calcium oxide caused by partial decomposition of calcium sulfate was observed in the specimens heat treated at temperatures higher than 1200°C. Although considerable improvements in cell viability of heat-treated scaffolds

  6. 3D-QSAR study of benzotriazol-1-yl carboxamide scaffold as monoacylglycerol lipase inhibitors

    PubMed Central

    Afzal, Obaid; Kumar, Suresh; Kumar, Rajiv; Jaggi, Manu; Bawa, Sandhya

    2014-01-01

    Purpose: The purpose of this study is to build up the 3D pharmacophore of Monoacylglycerol lipase (MAGL) inhibitor and to provide the basis to design the novel and potent MAGL inhibitors. Material and Method: A 3D-QSAR study on benztriazol-1-yl carboxamide derivatives as monoacylglycerol lipase (MAGL) inhibitors was successfully performed by means of pharmacophore mapping using PHASE 3.5 module of Schrφdinger-9.4. Result: The 3D-QSAR obtained from APRRR-105 hypothesis was found to be statistically good with r2 = 0.9228 and q2 = 0.871, taking PLS factor 4. The statistical significance of the model was also confirmed by a high value of Fisher's ratio of 82.8 and a very low value of root-mean-square error (RMSE) 0.2564. Another parameter which signifies the model predictivity is Pearson R. Its value of 0.9512 showed that the correlation between predicted and observed activities for the test set compounds is excellent. Conclusion: The study suggested that one H-bond acceptor, one positive center, and proper positioning of hydrophobic groups near the distal aromatic ring C are the crucial determinants for MAGL inhibition. Thus, it can be assumed that the present QSAR analysis is enough to demonstrate MAGL inhibition with the help of APRRR-105 hypothesis and will be helpful in designing novel and potent MAGL inhibitors. PMID:25400409

  7. Nanoscale Control of Silks for Nanofibrous Scaffold Formation with Improved Porous Structure.

    PubMed

    Lin, Shasha; Lu, Guozhong; Liu, Shanshan; Bai, Shumeng; Liu, Xi; Lu, Qiang; Zuo, Baoqi; Kaplan, David L; Zhu, Hesun

    2014-05-01

    Silk-based porous scaffolds have been used extensively in tissue engineering because of their excellent biocompatibility, tunable biodegradability and robust mechanical properties. Although many silk-based scaffolds have been prepared through freeze-drying, a challenge remains to effectively control porous structures during this process. In the present study silk fibroin with different nanostructures were self-assembled in aqueous solution by repeated drying-dissolving process and then used to improve porous structure formation in lyophilization process. Viscosity, secondary structures and water interactions were also studied to exclude their influence on the formation and control of porous structures. Following nanofiber formation in aqueous solution, silk scaffolds with improved porous structure were directly formed after lyophilization and then stabilized with water or methanol annealing treatments. Compared to silk scaffolds derived from fresh solution, the nanofibrous scaffolds showed significantly better cell compatibility in vitro. Therefore, this nanoscale control of silk offers feasible way to regulate the matrix features including porous structure and nanostructure, which are important in regulating cell and tissue outcomes in tissue engineering and regeneration, and then achieve silk-based scaffolds with improved properties. PMID:24949200

  8. Solvent-assisted room-temperature compression molding approach to fabricate porous scaffolds for tissue engineering.

    PubMed

    Jing, Dianying; Wu, Linbo; Ding, Jiandong

    2006-09-15

    This study investigated the room-temperature compression molding/particle leaching approach to fabricate three-dimensional porous scaffolds for tissue engineering. Scaffolds with anatomical shapes (ear, joint, tube, cylinder) were made from biodegradable poly(D,L-lactide) and poly[(D,L-lactide)-co-glycolide]. The utility of this room-temperature compression approach comes from the effect of solvent assistance, but the tendency for post-molding scaffold shrinkage is a problem unique to this method and is thus examined with emphasis in this paper. Scaffold shrinkage was found to be tolerable under normal fabrication conditions with high salt contents, which is just what the preparation of highly porous scaffolds requires. Furthermore, the resultant porosities after salt leaching were measured as well as the initial scaffold shrinkages after solvent evaporation, and the relation between them was revealed by theoretical analysis and confirmed by comparison with experimental measurements. The pores were interconnected, and porosity can exceed 90%. The effects of porosity on the mechanical properties of porous scaffolds were also investigated. This convenient fabrication approach is a prospective method for the tailoring of porous scaffolds for a variety of possible applications in tissue engineering and tissue reconstruction.

  9. Collagen-grafted porous HDPE/PEAA scaffolds for bone reconstruction.

    PubMed

    Kim, Chang-Shik; Jung, Kyung-Hye; Kim, Hun; Kim, Chan-Bong; Kang, Inn-Kyu

    2016-01-01

    After tumor resection, bone reconstruction such as skull base reconstruction using interconnected porous structure is absolutely necessary. In this study, porous scaffolds for bone reconstruction were prepared using heat-pressing and salt-leaching methods. High-density polyethylene (HDPE) and poly(ethylene-co-acrylic acid) (PEAA) were chosen as the polymer composites for producing a porous scaffold of high mechanical strength and having high reactivity with biomaterials such as collagen, respectively. The porous structure was observed through surface images, and its intrusion volume and porosity were measured. Owing to the carboxylic acids on PEAA, collagen was successfully grafted onto the porous HDPE/PEAA scaffold, which was confirmed by FT-IR spectroscopy and electron spectroscopy for chemical analysis. Osteoblasts were cultured on the collagen-grafted porous scaffold, and their adhesion, proliferation, and differentiation were investigated. The high viability and growth of the osteoblasts suggest that the collagen-grafted porous HDPE/PEAA is a promising scaffold material for bone generation. PMID:27468356

  10. Collagen-grafted porous HDPE/PEAA scaffolds for bone reconstruction.

    PubMed

    Kim, Chang-Shik; Jung, Kyung-Hye; Kim, Hun; Kim, Chan-Bong; Kang, Inn-Kyu

    2016-01-01

    After tumor resection, bone reconstruction such as skull base reconstruction using interconnected porous structure is absolutely necessary. In this study, porous scaffolds for bone reconstruction were prepared using heat-pressing and salt-leaching methods. High-density polyethylene (HDPE) and poly(ethylene-co-acrylic acid) (PEAA) were chosen as the polymer composites for producing a porous scaffold of high mechanical strength and having high reactivity with biomaterials such as collagen, respectively. The porous structure was observed through surface images, and its intrusion volume and porosity were measured. Owing to the carboxylic acids on PEAA, collagen was successfully grafted onto the porous HDPE/PEAA scaffold, which was confirmed by FT-IR spectroscopy and electron spectroscopy for chemical analysis. Osteoblasts were cultured on the collagen-grafted porous scaffold, and their adhesion, proliferation, and differentiation were investigated. The high viability and growth of the osteoblasts suggest that the collagen-grafted porous HDPE/PEAA is a promising scaffold material for bone generation.

  11. Fabrication of uniformly cell-laden porous scaffolds using a gas-in-liquid templating technique.

    PubMed

    Takei, Takayuki; Aokawa, Ryuta; Shigemitsu, Takamasa; Kawakami, Koei; Yoshida, Masahiro

    2015-11-01

    Design of porous scaffolds in tissue engineering field was challenging. Uniform immobilization of cells in the scaffolds with high porosity was essential for homogeneous tissue formation. The present study was aimed at fabricating uniformly cell-laden porous scaffolds with porosity >74% using the gas-in-liquid foam templating technique. To this end, we used gelatin, microbial transglutaminase and argon gas as a scaffold material, cross-linker of the protein and porogen of scaffold, respectively. We confirmed that a porosity of >74% could be achieved by increasing the gas volume delivered to a gelatin solution. Pore size in the scaffold could be controlled by stirring speed, stirring time and the pore size of the filter through which the gas passed. The foaming technique enabled us to uniformly immobilize a human hepatoblastoma cell line in scaffold. Engraftment efficiency of the cell line entrapped within the scaffold in nude mice was higher than that of cells in free-form. These results showed that the uniformly cell-laden porous scaffolds were promising for tissue engineering.

  12. High-resolution direct 3D printed PLGA scaffolds: print and shrink.

    PubMed

    Chia, Helena N; Wu, Benjamin M

    2014-12-17

    Direct three-dimensional printing (3DP) produces the final part composed of the powder and binder used in fabrication. An advantage of direct 3DP is control over both the microarchitecture and macroarchitecture. Prints which use porogen incorporated in the powder result in high pore interconnectivity, uniform porosity, and defined pore size after leaching. The main limitations of direct 3DP for synthetic polymers are the use of organic solvents which can dissolve polymers used in most printheads and limited resolution due to unavoidable spreading of the binder droplet after contact with the powder. This study describes a materials processing strategy to eliminate the use of organic solvent during the printing process and to improve 3DP resolution by shrinking with a non-solvent plasticizer. Briefly, poly(lactic-co-glycolic acid) (PLGA) powder was prepared by emulsion solvent evaporation to form polymer microparticles. The printing powder was composed of polymer microparticles dry mixed with sucrose particles. After printing with a water-based liquid binder, the polymer microparticles were fused together to form a network by solvent vapor in an enclosed vessel. The sucrose is removed by leaching and the resulting scaffold is placed in a solution of methanol. The methanol acts as a non-solvent plasticizer and allows for polymer chain rearrangement and efficient packing of polymer chains. The resulting volumetric shrinkage is ∼80% at 90% methanol. A complex shape (honey-comb) was designed, printed, and shrunken to demonstrate isotropic shrinking with the ability to reach a final resolution of ∼400 μm. The effect of type of alcohol (i.e. methanol or ethanol), concentration of alcohol, and temperature on volumetric shrinking was studied. This study presents a novel materials processing strategy to overcome the main limitations of direct 3DP to produce high resolution PLGA scaffolds.

  13. Sulfur-impregnated 3D hierarchical porous nitrogen-doped aligned carbon nanotubes as high-performance cathode for lithium-sulfur batteries

    NASA Astrophysics Data System (ADS)

    Deng, Weina; Hu, Aiping; Chen, Xiaohua; Zhang, Shiying; Tang, Qunli; Liu, Zheng; Fan, Binbin; Xiao, Kuikui

    2016-08-01

    A rational 3D hierarchical porous nitrogen-doped aligned carbon nanotubes (HPNACNTs) with well-directed 1D conductive electron paths is designed as scaffold to load sulfur. The HPNACNTs have abundant micropores, mesopores and macropores with a relatively high specific surface area and a large total pore volume. The sulfur-HPNACNTs composite is synthesized for lithium-sulfur batteries by a melt-diffusion of sulfur powders into HPNACNTs scaffolds. Electrochemical tests reveal that the sulfur-HPNACNTs (68.8 wt% sulfur) composite exhibits a high initial discharge capacity of 1340 mAh g-1 at 0.1 C and retains as high as 979 mAh g-1 at 0.2 C after 200 cycles. More importantly, it shows high reversible capacity at high rates (817 mAh g-1 at 5 C). Its enhanced electrochemical performance can be attributed to the excellent electrical conductivity of aligned carbon nanotubes, the synergetic effect of its hierarchical porosity and the restraint of the shuttle effect due to the SxLi … N interactions via the N lone-pair electron.

  14. Design of advanced porous graphene materials: from graphene nanomesh to 3D architectures.

    PubMed

    Jiang, Lili; Fan, Zhuangjun

    2014-02-21

    In order to make full utilization of the high intrinsic surface area of graphene, recently, porous graphene materials including graphene nanomesh, crumpled graphene and graphene foam, have attracted tremendous attention and research interest, owing to their exceptional porous structure (high surface area, and high pore volume) in combination with the inherent properties of graphene, such as high electronic conductivity, good thermal stability, and excellent mechanical strength. Interestingly, porous graphene materials and their derivatives have been explored in a wide range of applications in the fields of electronic and photonic devices, energy storage, gas separation/storage, oil absorption and sensors. This article reviews recent progress in the synthesis, characterization, properties, and applications of porous graphene materials. We aim to highlight the importance of designing different porous structures of graphene to meet future challenges, and the trend on future design of porous graphene materials is analyzed.

  15. Design of advanced porous graphene materials: from graphene nanomesh to 3D architectures

    NASA Astrophysics Data System (ADS)

    Jiang, Lili; Fan, Zhuangjun

    2014-01-01

    In order to make full utilization of the high intrinsic surface area of graphene, recently, porous graphene materials including graphene nanomesh, crumpled graphene and graphene foam, have attracted tremendous attention and research interest, owing to their exceptional porous structure (high surface area, and high pore volume) in combination with the inherent properties of graphene, such as high electronic conductivity, good thermal stability, and excellent mechanical strength. Interestingly, porous graphene materials and their derivatives have been explored in a wide range of applications in the fields of electronic and photonic devices, energy storage, gas separation/storage, oil absorption and sensors. This article reviews recent progress in the synthesis, characterization, properties, and applications of porous graphene materials. We aim to highlight the importance of designing different porous structures of graphene to meet future challenges, and the trend on future design of porous graphene materials is analyzed.

  16. Fabrication of chitosan-silver nanoparticle hybrid 3D porous structure as a SERS substrate for biomedical applications

    NASA Astrophysics Data System (ADS)

    Jung, Gyeong-Bok; Kim, Ji-Hye; Burm, Jin Sik; Park, Hun-Kuk

    2013-05-01

    We propose a simple, low-cost, large-area, and functional surface enhanced Raman scattering (SERS) substrate for biomedical applications. The SERS substrate with chitosan-silver nanoparticles (chitosan-Ag NPs) hybrid 3D porous structure was fabricated simply by a one-step method. The chitosan was used as a template for the Ag NPs deposition. SERS enhancement by the chitosan-Ag NPs substrate was experimentally verified using rhodamine B as an analyte. Thiolated single stranded DNA was also measured for atopic dermatitis genetic markers (chemokines CCL17) at a low concentration of 5 pM. We successfully designed a novel SERS substrate with silver nanoparticle hybridized 3D porous chitosan that has the potential to become a highly sensitive and selective tool for biomedical applications.

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

    PubMed

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

    2015-12-01

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

  18. From micro-scale 3D simulations to macro-scale model of periodic porous media

    NASA Astrophysics Data System (ADS)

    Crevacore, Eleonora; Tosco, Tiziana; Marchisio, Daniele; Sethi, Rajandrea; Messina, Francesca

    2015-04-01

    In environmental engineering, the transport of colloidal suspensions in porous media is studied to understand the fate of potentially harmful nano-particles and to design new remediation technologies. In this perspective, averaging techniques applied to micro-scale numerical simulations are a powerful tool to extrapolate accurate macro-scale models. Choosing two simplified packing configurations of soil grains and starting from a single elementary cell (module), it is possible to take advantage of the periodicity of the structures to reduce the computation costs of full 3D simulations. Steady-state flow simulations for incompressible fluid in laminar regime are implemented. Transport simulations are based on the pore-scale advection-diffusion equation, that can be enriched introducing also the Stokes velocity (to consider the gravity effect) and the interception mechanism. Simulations are carried on a domain composed of several elementary modules, that serve as control volumes in a finite volume method for the macro-scale method. The periodicity of the medium involves the periodicity of the flow field and this will be of great importance during the up-scaling procedure, allowing relevant simplifications. Micro-scale numerical data are treated in order to compute the mean concentration (volume and area averages) and fluxes on each module. The simulation results are used to compare the micro-scale averaged equation to the integral form of the macroscopic one, making a distinction between those terms that could be computed exactly and those for which a closure in needed. Of particular interest it is the investigation of the origin of macro-scale terms such as the dispersion and tortuosity, trying to describe them with micro-scale known quantities. Traditionally, to study the colloidal transport many simplifications are introduced, such those concerning ultra-simplified geometry that usually account for a single collector. Gradual removal of such hypothesis leads to a

  19. Using a decellularized splenic matrix as a 3D scaffold for hepatocyte cultivation in vitro: a preliminary trial.

    PubMed

    Zheng, Xing-Long; Xiang, Jun-Xi; Wu, Wan-Quan; Wang, Bo; Liu, Wen-Yan; Gao, Rui; Dong, Ding-Hui; Lv, Yi

    2015-08-01

    Using a decellularized liver matrix (DLM) to reengineer liver tissue is a promising therapy for end-stage liver disease. However, the limited supply of donor organs still hampers its potential clinical application, while a xenogenic decellularized matrix may bring a risk of zoonosis and immunological rejection. Therefore, an appropriate alternative scaffold is needed. In this research, we established a decellularized splenic matrix (DSM) in a rodent model, which preserved the 3D ultrastructure, the components of the extracellular matrix (ECM) and the native vascular network. The DSM and DLM had similar components of ECM, and similar mechanical properties. Hepatocytes were seeded to the DSM and DLM for dynamic culturing up to 6 d, and distributed both in decellularized sinusoidal spaces and around the vessels. The TUNEL-positive cell percentage in a dynamic culturing decellularized splenic matrix (dDSM) was 10.7%  ±  3.6% at 3d and 25.8%  ±  5.6% at 5d, although 14.2%  ±  4.5% and 24.8%  ±  2.9%, respectively, in a dynamic culturing decellularized liver matrix (dDLM) at the same time point (p  >  0.05). Primary hepatocytes in the dDSM and dDLM expressed albumin, G6pc and Ugt1a1. The gene expression of Cyp2b1, Cyp1a2 and HNF1α in the gene transcription level revealed hepatocytes had lower gene expression levels in the dDSM compared with the dDLM at 3d, but better than those in a sandwich culture. The cumulative albumin production at 6 d of culture was 80.7   ±   9.6 μg per million cells in the dDSM and 89.6   ±   4.6 μg per million cells in the dDLM (p  >  0.05). In summary, the DSM is a promising 3D scaffold for hepatocyte cultivation in vitro. PMID:26290516

  20. Processing and characterization of chitosan/PVA and methylcellulose porous scaffolds for tissue engineering.

    PubMed

    Kanimozhi, K; Khaleel Basha, S; Sugantha Kumari, V

    2016-04-01

    Biomimetic porous scaffold chitosan/poly(vinyl alcohol) CS/PVA containing various amounts of methylcellulose (MC) (25%, 50% and 75%) incorporated in CS/PVA blend was successfully produced by a freeze drying method in the present study. The composite porous scaffold membranes were characterized by infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), swelling degree, porosity, degradation of films in Hank's solution and the mechanical properties. Besides these characterizations, the antibacterial activity of the prepared scaffolds was tested, toward the bacterial species Staphylococcus aureus (S.aureus) and Escherichia coli (E.coli). FTIR, XRD and DSC demonstrated that there was strong intermolecular hydrogen bonding between the molecules of CS/PVA and MC. The crystalline microstructure of the scaffold membranes was not well developed. SEM images showed that the morphology and diameter of the scaffolds were mainly affected by the weight ratio of MC. By increasing the MC content in the hybrid scaffolds, their swelling capacity and porosity increased. The mechanical properties of these scaffolds in dry and swollen state were greatly improved with high swelling ratio. The elasticity of films was also significantly improved by the incorporation of MC, and the scaffolds could also bear a relative high tensile strength. These findings suggested that the developed scaffold possess the prerequisites and can be used as a scaffold for tissue engineering. PMID:26838875

  1. Heat- and pH-induced BSA conformational changes, hydrogel formation and application as 3D cell scaffold.

    PubMed

    Navarra, Giovanna; Peres, Chiara; Contardi, Marco; Picone, Pasquale; San Biagio, Pier Luigi; Di Carlo, Marta; Giacomazza, Daniela; Militello, Valeria

    2016-09-15

    Aggregation and gelation of globular proteins can be an advantage to generate new forms of nanoscale biomaterials based on the fibrillar architecture. Here, we report results obtained by exploiting the proteins' natural tendency to self-organize in 3D network, for the production of new material based on BSA for medical application. In particular, at five different pH values the conformational and structural changes of the BSA during all the steps of the thermal aggregation and gelation have been analyzed by FTIR spectroscopy. The macroscopic mechanical properties of these hydrogels have been obtained by rheological measurements. The microscopic structure of the gels have been studied by AFM and SEM images to have a picture of their different spatial arrangement. Finally, the use of the BSA hydrogels as scaffold has been tested in two different cell cultures. PMID:27480606

  2. Heat- and pH-induced BSA conformational changes, hydrogel formation and application as 3D cell scaffold.

    PubMed

    Navarra, Giovanna; Peres, Chiara; Contardi, Marco; Picone, Pasquale; San Biagio, Pier Luigi; Di Carlo, Marta; Giacomazza, Daniela; Militello, Valeria

    2016-09-15

    Aggregation and gelation of globular proteins can be an advantage to generate new forms of nanoscale biomaterials based on the fibrillar architecture. Here, we report results obtained by exploiting the proteins' natural tendency to self-organize in 3D network, for the production of new material based on BSA for medical application. In particular, at five different pH values the conformational and structural changes of the BSA during all the steps of the thermal aggregation and gelation have been analyzed by FTIR spectroscopy. The macroscopic mechanical properties of these hydrogels have been obtained by rheological measurements. The microscopic structure of the gels have been studied by AFM and SEM images to have a picture of their different spatial arrangement. Finally, the use of the BSA hydrogels as scaffold has been tested in two different cell cultures.

  3. 3D hierarchical porous graphene aerogel with tunable meso-pores on graphene nanosheets for high-performance energy storage

    PubMed Central

    Ren, Long; Hui, K. N.; Hui, K. S.; Liu, Yundan; Qi, Xiang; Zhong, Jianxin; Du, Yi; Yang, Jianping

    2015-01-01

    New and novel 3D hierarchical porous graphene aerogels (HPGA) with uniform and tunable meso-pores (e.g., 21 and 53 nm) on graphene nanosheets (GNS) were prepared by a hydrothermal self-assembly process and an in-situ carbothermal reaction. The size and distribution of the meso-pores on the individual GNS were uniform and could be tuned by controlling the sizes of the Co3O4 NPs used in the hydrothermal reaction. This unique architecture of HPGA prevents the stacking of GNS and promises more electrochemically active sites that enhance the electrochemical storage level significantly. HPGA, as a lithium-ion battery anode, exhibited superior electrochemical performance, including a high reversible specific capacity of 1100 mAh/g at a current density of 0.1 A/g, outstanding cycling stability and excellent rate performance. Even at a large current density of 20 A/g, the reversible capacity was retained at 300 mAh/g, which is larger than that of most porous carbon-based anodes reported, suggesting it to be a promising candidate for energy storage. The proposed 3D HPGA is expected to provide an important platform that can promote the development of 3D topological porous systems in a range of energy storage and generation fields. PMID:26382852

  4. Unimpeded permeation of water through biocidal graphene oxide sheets anchored on to 3D porous polyolefinic membranes.

    PubMed

    Mural, Prasanna Kumar S; Jain, Shubham; Kumar, Sachin; Madras, Giridhar; Bose, Suryasarathi

    2016-04-21

    3D porous membranes were developed by etching one of the phases (here PEO, polyethylene oxide) from melt-mixed PE/PEO binary blends. Herein, we have systematically discussed the development of these membranes using X-ray micro-computed tomography. The 3D tomograms of the extruded strands and hot-pressed samples revealed a clear picture as to how the morphology develops and coarsens over a function of time during post-processing operations like compression molding. The coarsening of PE/PEO blends was traced using X-ray micro-computed tomography and scanning electron microscopy (SEM) of annealed blends at different times. It is now understood from X-ray micro-computed tomography that by the addition of a compatibilizer (here lightly maleated PE), a stable morphology can be visualized in 3D. In order to anchor biocidal graphene oxide sheets onto these 3D porous membranes, the PE membranes were chemically modified with acid/ethylene diamine treatment to anchor the GO sheets which were further confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and surface Raman mapping. The transport properties through the membrane clearly reveal unimpeded permeation of water which suggests that anchoring GO on to the membranes does not clog the pores. Antibacterial studies through the direct contact of bacteria with GO anchored PE membranes resulted in 99% of bacterial inactivation. The possible bacterial inactivation through physical disruption of the bacterial cell wall and/or reactive oxygen species (ROS) is discussed herein. Thus this study opens new avenues in designing polyolefin based antibacterial 3D porous membranes for water purification.

  5. Fabrication and characterization of porous EH scaffolds and EH-PEG bilayers.

    PubMed

    Falco, Erin E; Coates, Emily E; Li, Erik; Roth, J Scott; Fisher, John P

    2011-06-01

    Biomaterials made from synthetic polymers are becoming more pervasive in the medical field. Synthetic polymers are particularly advantageous as their chemical and mechanical properties can be easily tailored to a specific application. This work characterizes polymer scaffolds derived from the cyclic acetal monomer 5-ethyl-5-(hydroxymethyl)-β,β-dimethyl-1,3-dioxane-2-ethanol diacrylate (EHD). Both porous scaffolds and bilayer scaffolds based upon the EHD monomer were fabricated, and the resulting scaffolds' degradation and mechanical properties were studied. The results showed that by modifying the architecture of an EH scaffold, either by adding a porous network or a poly(ethylene glycol) (PEG) coating, the degradation and Young's modulus of the biomaterial can be significant altered. However, results also indicated that these architectural modifications can be accomplished without a significant loss in the flexural strength of the scaffold. Therefore, we suggest that porous EH scaffolds, and particularly porous EH-PEG bilayers, may be especially useful in dynamic tissue environments due to their advantageous architectural and mechanical properties. PMID:21442727

  6. Development of porous Ti6Al4V/chitosan sponge composite scaffold for orthopedic applications.

    PubMed

    Guo, Miao; Li, Xiang

    2016-01-01

    A novel composite scaffold consisting of porous Ti6Al4V part filled with chitosan sponge was fabricated using a combination of electron beam melting and freeze-drying. The mechanical properties of porous Ti6Al4V part were examined via compressive test. The ultimate compressive strength was 85.35 ± 8.68 MPa and the compressive modulus was 2.26 ± 0.42 GPa. The microstructure of composite scaffold was characterized using scanning electron microscopy. The chitosan sponge filled in Ti6Al4V part exhibited highly porous and well-interconnected micro-pore architecture. The osteoblastic cells were seeded on scaffolds to test their seeding efficiency and biocompatibility. Significantly higher cell seeding efficiency was found on composite scaffold. The biological response of osteoblasts on composite scaffolds was superior in terms of improved cell attachment, higher proliferation, and well-spread morphology in relation to porous Ti6Al4V part. These results suggest that the Ti6Al4V/chitosan composite scaffold is potentially useful as a biomedical scaffold for orthopedic applications. PMID:26478418

  7. Development of porous Ti6Al4V/chitosan sponge composite scaffold for orthopedic applications.

    PubMed

    Guo, Miao; Li, Xiang

    2016-01-01

    A novel composite scaffold consisting of porous Ti6Al4V part filled with chitosan sponge was fabricated using a combination of electron beam melting and freeze-drying. The mechanical properties of porous Ti6Al4V part were examined via compressive test. The ultimate compressive strength was 85.35 ± 8.68 MPa and the compressive modulus was 2.26 ± 0.42 GPa. The microstructure of composite scaffold was characterized using scanning electron microscopy. The chitosan sponge filled in Ti6Al4V part exhibited highly porous and well-interconnected micro-pore architecture. The osteoblastic cells were seeded on scaffolds to test their seeding efficiency and biocompatibility. Significantly higher cell seeding efficiency was found on composite scaffold. The biological response of osteoblasts on composite scaffolds was superior in terms of improved cell attachment, higher proliferation, and well-spread morphology in relation to porous Ti6Al4V part. These results suggest that the Ti6Al4V/chitosan composite scaffold is potentially useful as a biomedical scaffold for orthopedic applications.

  8. Fabrication and mechanical characterization of 3D electrospun scaffolds for tissue engineering.

    PubMed

    Wright, L D; Young, R T; Andric, T; Freeman, J W

    2010-10-01

    Electrospinning is a polymer processing technique that produces fibrous structures comparable to the extracellular matrix of many tissues. Electrospinning, however, has been severely limited in its tissue engineering capabilities because this technique has produced few three-dimensional structures. Sintering of electrospun materials provides a method to fabricate unique architectures and allow much larger structures to be made. Electrospun mats were sintered into strips and cylinders, and their tensile and compressive mechanical properties were measured. In addition, electrospun materials with salt pores (salt embedded within the material and then leached out) were fabricated to improve porosity of the electrospun materials for tissue engineering scaffolds. Sintered electrospun poly(D,L-lactide) and poly(L-lactide) (PDLA/PLLA) materials have higher tensile mechanical properties (modulus: 72.3 MPa, yield: 960 kPa) compared to unsintered PLLA (modulus: 40.36 MPa, yield: 675.5 kPa). Electrospun PDLA/PLLA cylinders with and without salt-leached pores had compressive moduli of 6.69 and 26.86 MPa, respectively, and compressive yields of 1.36 and 0.56 MPa, respectively. Sintering of electrospun materials is a novel technique that improves electrospinning application in tissue engineering by increasing the size and types of electrospun structures that can be fabricated.

  9. Synthesis of SiO2/3D porous carbon composite as anode material with enhanced lithium storage performance

    NASA Astrophysics Data System (ADS)

    Yuan, Zhinan; Zhao, Naiqin; Shi, Chunsheng; Liu, Enzuo; He, Chunnian; He, Fang

    2016-05-01

    A SiO2/porous carbon nanocomposite was synthesized by a facile combined heat and acid treatments method. The nanocomposite featured a 3D porous carbon structure with amorphous SiO2 nanoparticles embedded in the wall of the pores. The microstructure improved the electrical conductivity, shortened the diffusion distance of lithium ions, and alleviated the volume expansion of SiO2 during Li intercalation. Accordingly, the SiO2/porous carbon nanocomposite displayed excellent cyclic performance with a high reversible capacity of 434 mAh g-1 after 50 cycles at 0.1 A g-1 and rate capability delivering a capacity of 187.4 mAh g-1 even at 5 A g-1.

  10. Alginate/nanohydroxyapatite scaffolds with designed core/shell structures fabricated by 3D plotting and in situ mineralization for bone tissue engineering.

    PubMed

    Luo, Yongxiang; Lode, Anja; Wu, Chengtie; Chang, Jiang; Gelinsky, Michael

    2015-04-01

    Composite scaffolds, especially polymer/hydroxyapatite (HAP) composite scaffolds with predesigned structures, are promising materials for bone tissue engineering. Various methods including direct mixing of HAP powder with polymers or incubating polymer scaffolds in simulated body fluid for preparing polymer/HAP composite scaffolds are either uncontrolled or require long times of incubation. In this work, alginate/nano-HAP composite scaffolds with designed pore parameters and core/shell structures were fabricated using 3D plotting technique and in situ mineralization under mild conditions (at room temperature and without the use of any organic solvents). Light microscopy, scanning electron microscopy, microcomputer tomography, X-ray diffraction, and Fourier transform infrared spectroscopy were applied to characterize the fabricated scaffolds. Mechanical properties and protein delivery of the scaffolds were evaluated, as well as the cell response to the scaffolds by culturing human bone-marrow-derived mesenchymal stem cells (hBMSC). The obtained data indicate that this method is suitable to fabricate alginate/nano-HAP composite scaffolds with a layer of nano-HAP, coating the surface of the alginate strands homogeneously and completely. The surface mineralization enhanced the mechanical properties and improved the cell attachment and spreading, as well as supported sustaining protein release, compared to pure alginate scaffolds without nano-HAP shell layer. The results demonstrated that the method provides an interesting option for bone tissue engineering application.

  11. Biofunctionalization of electrospun PCL-based scaffolds with perlecan domain IV peptide to create a 3-D pharmacokinetic cancer model

    PubMed Central

    Hartman, Olga; Zhang, Chu; Adams, Elizabeth L.; Farach-Carson, Mary C.; Petrelli, Nicholas J.; Chase, Bruce D.; Rabolt, John F.

    2010-01-01

    Because prostate cancer cells metastasize to bone and exhibit osteoblastic features (osteomimicry), the interrelationships between bone-specific microenvironment and prostate cancer cells at sites of bone metastasis are critical to disease progression. In this work the bone marrow microenvironment in vitro was recreated both by tailoring scaffolds physical properties and by functionalizing electrospun polymer fibers with a bioactive peptide derived from domain IV of perlecan heparan sulfate proteoglycan. Electrospun poly (ε-caprolactone) (PCL) fibers and PCL/gelatin composite scaffolds were modified covalently with perlecan domain IV (PlnDIV) peptide. The expression of tight junction protein (E-cadherin) and focal adhesion kinase (FAK) phosphorylation on tyrosine 397 also were investigated. The described bioactive motif significantly enhanced adherence and infiltration of the metastatic prostate cancer cells on all modified electrospun substrates by day 5 post-seeding. Cells cultured on PlnDIV-modified matrices organized stress fibers and increased proliferation at statistically significant rates. Additional findings suggest that presence of PlnDIV peptide in the matrix reduced expression of tight junction protein and binding to PlnDIV peptide was accompanied by increased focal adhesion kinase (FAK) phosphorylation on tyrosine 397. We conclude that PlnDIV peptide supports key signaling events leading to proliferation, survival, and migration of C4-2B cancer cells; hence its incorporation into electrospun matrix is a key improvement to create a successful three-dimensional (3-D) pharmacokinetic cancer model. PMID:20417554

  12. Novel 3D scaffold with enhanced physical and cell response properties for bone tissue regeneration, fabricated by patterned electrospinning/electrospraying.

    PubMed

    Hejazi, Fatemeh; Mirzadeh, Hamid

    2016-09-01

    Developing three dimensional scaffolds mimicking the nanoscale structure of native extracellular matrix is a key parameter in tissue regeneration. In this study, we aimed to introduce a novel 3D structures composed of nanofibers (NF) and micro particles (MP) and compare their efficiency with 2D nanofibrous scaffold. The conventional nanofibrous PCL scaffolds are 2D mats fabricated by the electrospinning technique, whereas the NF/MP and patterned NF/MP PCL scaffolds are three dimensional structures fabricated by a modified electrospinning/electrospraying technique. The mentioned method was carried out by varying the electrospinning solution parameters and use of a metal mesh as the collector. Detailed fabrication process and morphological properties of the fabricated structures is discussed and porosity, pore size and PBS solution absorption value of the prepared structures are reported. Compared with the 2D structure, 3D scaffolds possessed enhanced porosity and pore size which led to the significant increase in their water uptake capacity. In vitro cell experiments were carried out on the prepared structures by the use of MG-63 osteosarcoma cell line. The fabricated 3D structures offered significantly increased cell attachment, spread and diffusion which were confirmed by SEM analysis. In vitro cytocompatibility assessed by MTT colorimetric assay indicated a continuous cell proliferation over 21 days on the innovative 3D structure, while on 2D mat cell proliferation stopped at early time points. Enhanced osteogenic differentiation of the seeded MG-63 cells on 3D scaffold was confirmed by the remarkable ALP activity together with increased and accelerated calcium deposition on this structure compared to 2D mat. Massive and well distributed bone minerals formed on patterned 3D structure were shown by EDX analysis. In comparison between NF/MP quasi-3D and Patterned NF/MP 3D scaffolds, patterned structures proceeded in all of the above properties. As such, the

  13. Novel 3D scaffold with enhanced physical and cell response properties for bone tissue regeneration, fabricated by patterned electrospinning/electrospraying.

    PubMed

    Hejazi, Fatemeh; Mirzadeh, Hamid

    2016-09-01

    Developing three dimensional scaffolds mimicking the nanoscale structure of native extracellular matrix is a key parameter in tissue regeneration. In this study, we aimed to introduce a novel 3D structures composed of nanofibers (NF) and micro particles (MP) and compare their efficiency with 2D nanofibrous scaffold. The conventional nanofibrous PCL scaffolds are 2D mats fabricated by the electrospinning technique, whereas the NF/MP and patterned NF/MP PCL scaffolds are three dimensional structures fabricated by a modified electrospinning/electrospraying technique. The mentioned method was carried out by varying the electrospinning solution parameters and use of a metal mesh as the collector. Detailed fabrication process and morphological properties of the fabricated structures is discussed and porosity, pore size and PBS solution absorption value of the prepared structures are reported. Compared with the 2D structure, 3D scaffolds possessed enhanced porosity and pore size which led to the significant increase in their water uptake capacity. In vitro cell experiments were carried out on the prepared structures by the use of MG-63 osteosarcoma cell line. The fabricated 3D structures offered significantly increased cell attachment, spread and diffusion which were confirmed by SEM analysis. In vitro cytocompatibility assessed by MTT colorimetric assay indicated a continuous cell proliferation over 21 days on the innovative 3D structure, while on 2D mat cell proliferation stopped at early time points. Enhanced osteogenic differentiation of the seeded MG-63 cells on 3D scaffold was confirmed by the remarkable ALP activity together with increased and accelerated calcium deposition on this structure compared to 2D mat. Massive and well distributed bone minerals formed on patterned 3D structure were shown by EDX analysis. In comparison between NF/MP quasi-3D and Patterned NF/MP 3D scaffolds, patterned structures proceeded in all of the above properties. As such, the

  14. Interview: bioreactors and surfaced-modified 3D-scaffolds for stem cell research.

    PubMed

    Weibezahn, Karl-Friedrich

    2008-01-01

    A Nature Editorial in 2003 asked the question "Good-bye, flat biology?" What does this question imply? In the past, many in vitro culture systems, mainly monolayer cultures, often suffered from the disadvantage that differentiated primary cells had a relatively short life-span and de-differentiated during culture. As a consequence, most of their organ-specific functions were lost rapidly. Thus, in order to reproduce better conditions for these cells in vitro, modifications and adaptations have been made to conventional monolayer cultures. The last generation of CellChips--micro-thermoformed containers--a specific technology was developed, which offers the additional possibility to modify the whole surface of the 3D formed containers. This allows a surface-patterning on a submicron scale with distinct signalling molecules. Sensors and signal electrodes may be incorporated. Applications range from basic research in cell biology to toxicology and pharmacology. Using biodegradable polymers, clinical applications become a possibility. Furthermore, the last generation of micro-thermoformed chips has been optimized to allow for cheap mass production.

  15. Interview: Bioreactors and Surfaced-Modified 3D-Scaffolds for Stem Cell Research

    PubMed Central

    Weibezahn, Karl-Friedrich

    2008-01-01

    A Nature Editorial in 2003 asked the question "Good-bye, flat biology?" What does this question imply? In the past, many in vitro culture systems, mainly monolayer cultures, often suffered from the disadvantage that differentiated primary cells had a relatively short life-span and de-differentiated during culture. As a consequence, most of their organ-specific functions were lost rapidly. Thus, in order to reproduce better conditions for these cells in vitro, modifications and adaptations have been made to conventional monolayer cultures. The last generation of CellChips -- micro-thermoformed containers -- a specific technology was developed, which offers the additional possibility to modify the whole surface of the 3D formed containers. This allows a surface-patterning on a submicron scale with distinct signalling molecules. Sensors and signal electrodes may be incorporated. Applications range from basic research in cell biology to toxicology and pharmacology. Using biodegradable polymers, clinical applications become a possibility. Furthermore, the last generation of micro-thermoformed chips has been optimized to allow for cheap mass production. PMID:19066581

  16. Association of electrospinning with electrospraying: a strategy to produce 3D scaffolds with incorporated stem cells for use in tissue engineering.

    PubMed

    Braghirolli, Daikelly Iglesias; Zamboni, Fernanda; Acasigua, Gerson A X; Pranke, Patricia

    2015-01-01

    In tissue engineering, a uniform cell occupation of scaffolds is crucial to ensure the success of tissue regeneration. However, this point remains an unsolved problem in 3D scaffolds. In this study, a direct method to integrate cells into fiber scaffolds was investigated by combining the methods of electrospinning of fibers and bioelectrospraying of cells. With the associating of these methods, the cells were incorporated into the 3D scaffolds while the fibers were being produced. The scaffolds containing cells (SCCs) were produced using 20% poly(lactide-co-glycolide) solution for electrospinning and mesenchymal stem cells from deciduous teeth as a suspension for bioelectrospraying. After their production, the SCCs were cultivated for 15 days at 37°C with an atmosphere of 5% CO2. The 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide test demonstrated that the cells remained viable and were able to grow between the fibers. Scanning electron microscopy showed the presence of a high number of cells in the structure of the scaffolds and confocal images demonstrated that the cells were able to adapt and spread between the fibers. Histological analysis of the SCCs after 1 day of cultivation showed that the cells were uniformly distributed throughout the thickness of the scaffolds. Some physicochemical properties of the scaffolds were also investigated. SCCs exhibited good mechanical properties, compatible with their handling and further implantation. The results obtained in the present study suggest that the association of electrospinning and bioelectrospraying provides an interesting tool for forming 3D cell-integrated scaffolds, making it a viable alternative for use in tissue engineering.

  17. Association of electrospinning with electrospraying: a strategy to produce 3D scaffolds with incorporated stem cells for use in tissue engineering

    PubMed Central

    Braghirolli, Daikelly Iglesias; Zamboni, Fernanda; Acasigua, Gerson AX; Pranke, Patricia

    2015-01-01

    In tissue engineering, a uniform cell occupation of scaffolds is crucial to ensure the success of tissue regeneration. However, this point remains an unsolved problem in 3D scaffolds. In this study, a direct method to integrate cells into fiber scaffolds was investigated by combining the methods of electrospinning of fibers and bioelectrospraying of cells. With the associating of these methods, the cells were incorporated into the 3D scaffolds while the fibers were being produced. The scaffolds containing cells (SCCs) were produced using 20% poly(lactide-co-glycolide) solution for electrospinning and mesenchymal stem cells from deciduous teeth as a suspension for bioelectrospraying. After their production, the SCCs were cultivated for 15 days at 37°C with an atmosphere of 5% CO2. The 3-(4,5-dimethylthiazol- 2-yl)-2,5-diphenyltetrazolium bromide test demonstrated that the cells remained viable and were able to grow between the fibers. Scanning electron microscopy showed the presence of a high number of cells in the structure of the scaffolds and confocal images demonstrated that the cells were able to adapt and spread between the fibers. Histological analysis of the SCCs after 1 day of cultivation showed that the cells were uniformly distributed throughout the thickness of the scaffolds. Some physicochemical properties of the scaffolds were also investigated. SCCs exhibited good mechanical properties, compatible with their handling and further implantation. The results obtained in the present study suggest that the association of electrospinning and bioelectrospraying provides an interesting tool for forming 3D cell-integrated scaffolds, making it a viable alternative for use in tissue engineering. PMID:26316747

  18. Injectable porous nano-hydroxyapatite/chitosan/tripolyphosphate scaffolds with improved compressive strength for bone regeneration.

    PubMed

    Uswatta, Suren P; Okeke, Israel U; Jayasuriya, Ambalangodage C

    2016-12-01

    In this study we have fabricated porous injectable spherical scaffolds using chitosan biopolymer, sodium tripolyphosphate (TPP) and nano-hydroxyapatite (nHA). TPP was primarily used as an ionic crosslinker to crosslink nHA/chitosan droplets. We hypothesized that incorporating nHA into chitosan could support osteoconduction by emulating the mineralized cortical bone structure, and improve the Ultimate Compressive Strength (UCS) of the scaffolds. We prepared chitosan solutions with 0.5%, 1% and 2% (w/v) nHA concentration and used simple coacervation and lyophilization techniques to obtain spherical scaffolds. Lyophilized spherical scaffolds had a mean diameter of 1.33mm (n=25). Further, portion from each group lyophilized scaffolds were soaked and dried to obtain Lyophilized Soaked and Dried (LSD) scaffolds. LSD scaffolds had a mean diameter of 0.93mm (n=25) which is promising property for the injectability. Scanning Electron Microscopy images showed porous surface morphology and interconnected pore structures inside the scaffolds. Lyophilized and LSD scaffolds had surface pores <10 and 2μm, respectively. 2% nHA/chitosan LSD scaffolds exhibited UCS of 8.59MPa compared to UCS of 2% nHA/chitosan lyophilized scaffolds at 3.93MPa. Standardize UCS values were 79.98MPa and 357MPa for 2% nHA/chitosan lyophilized and LSD particles respectively. One-way ANOVA results showed a significant increase (p<0.001) in UCS of 1% and 2% nHA/chitosan lyophilized scaffolds compared to 0% and 0.5% nHA/chitosan lyophilized scaffolds. Moreover, 2% nHA LSD scaffolds had significantly increased (p<0.005) their mean UCS by 120% compared to 2% nHA lyophilized scaffolds. In a drawback, all scaffolds have lost their mechanical properties by 95% on the 2nd day when fully immersed in phosphate buffered saline. Additionally live and dead cell assay showed no cytotoxicity and excellent osteoblast attachment to both lyophilized and LSD scaffolds at the end of 14th day of in vitro studies. 2% n

  19. Activation of Transcription Factor GAX and Concomitant Downregulation of IL-1β and ERK1/2 Modulate Vascular Smooth Muscle Cell Phenotype in 3D Fibrous Scaffolds.

    PubMed

    Lin, Shigang; Mequanint, Kibret

    2015-09-01

    Since vascular smooth muscle cells (VSMCs) display phenotypic plasticity in response to changing environmental cues, understanding the molecular mechanisms underlying the phenotypic modulation mediated by a three-dimensional (3D) scaffold is important to engineer functional vasculature. Following cell seeding into 3D scaffolds, the synthetic phenotype is desired to enable cells to expand rapidly and produce and assemble extracellular matrix components, but must revert to a quiescent contractile phenotype after tissue fabrication to impart the contractile properties found in native blood vessels. This study shows that 3D electrospun fibrous scaffolds regulate human coronary artery smooth muscle cells (HCASMCs) toward a more synthetic phenotype characterized by reduced contractile markers, such as smooth muscle alpha-actin and calponin. The reduction in contractile markers expression was mediated by endogenously expressed proinflammatory cytokine interleukin-1β (IL-1β). 3D topography transiently induces concomitant upregulation of IL-1β and MAPK ERK1/2 through nuclear factor-κB-dependent signaling pathway. An early burst of expression of IL-1β is essential for suppression of the homeobox transcription factor Gax and related cyclin-dependent kinase inhibitor p21(Cip1), which are key regulators for cells exiting from cell cycle. Our findings provide new insights for understanding signaling mechanisms of HCASMCs in electrospun 3D fibrous scaffolds, which have considerable value for application in vascular tissue engineering. PMID:26041434

  20. A novel open-porous magnesium scaffold with controllable microstructures and properties for bone regeneration

    NASA Astrophysics Data System (ADS)

    Cheng, Meng-Qi; Wahafu, Tuerhongjiang; Jiang, Guo-Feng; Liu, Wei; Qiao, Yu-Qin; Peng, Xiao-Chun; Cheng, Tao; Zhang, Xian-Long; He, Guo; Liu, Xuan-Yong

    2016-04-01

    The traditional production methods of porous magnesium scaffolds are difficult to accurately control the pore morphologies and simultaneously obtain appropriate mechanical properties. In this work, two open-porous magnesium scaffolds with different pore size but in the nearly same porosity are successfully fabricated with high-purity Mg ingots through the titanium wire space holder (TWSH) method. The porosity and pore size can be easily, precisely and individually controlled, as well as the mechanical properties also can be regulated to be within the range of human cancellous bone by changing the orientation of pores without sacrifice the requisite porous structures. In vitro cell tests indicate that the scaffolds have good cytocompatibility and osteoblastic differentiation properties. In vivo findings demonstrate that both scaffolds exhibit acceptable inflammatory responses and can be almost fully degraded and replaced by newly formed bone. More importantly, under the same porosity, the scaffolds with larger pore size can promote early vascularization and up-regulate collagen type 1 and OPN expression, leading to higher bone mass and more mature bone formation. In conclusion, a new method is introduced to develop an open-porous magnesium scaffold with controllable microstructures and mechanical properties, which has great potential clinical application for bone reconstruction in the future.

  1. A novel open-porous magnesium scaffold with controllable microstructures and properties for bone regeneration

    PubMed Central

    Cheng, Meng-qi; Wahafu, Tuerhongjiang; Jiang, Guo-feng; Liu, Wei; Qiao, Yu-qin; Peng, Xiao-chun; Cheng, Tao; Zhang, Xian-long; He, Guo; Liu, Xuan-yong

    2016-01-01

    The traditional production methods of porous magnesium scaffolds are difficult to accurately control the pore morphologies and simultaneously obtain appropriate mechanical properties. In this work, two open-porous magnesium scaffolds with different pore size but in the nearly same porosity are successfully fabricated with high-purity Mg ingots through the titanium wire space holder (TWSH) method. The porosity and pore size can be easily, precisely and individually controlled, as well as the mechanical properties also can be regulated to be within the range of human cancellous bone by changing the orientation of pores without sacrifice the requisite porous structures. In vitro cell tests indicate that the scaffolds have good cytocompatibility and osteoblastic differentiation properties. In vivo findings demonstrate that both scaffolds exhibit acceptable inflammatory responses and can be almost fully degraded and replaced by newly formed bone. More importantly, under the same porosity, the scaffolds with larger pore size can promote early vascularization and up-regulate collagen type 1 and OPN expression, leading to higher bone mass and more mature bone formation. In conclusion, a new method is introduced to develop an open-porous magnesium scaffold with controllable microstructures and mechanical properties, which has great potential clinical application for bone reconstruction in the future. PMID:27071777

  2. Tissue Engineering: Construction of a Multicellular 3D Scaffold for the Delivery of Layered Cell Sheets

    PubMed Central

    Turner, William S.; Sandhu, Nabjot; McCloskey, Kara E.

    2014-01-01

    Many tissues, such as the adult human hearts, are unable to adequately regenerate after damage.2,3 Strategies in tissue engineering propose innovations to assist the body in recovery and repair. For example, TE approaches may be able to attenuate heart remodeling after myocardial infarction (MI) and possibly increase total heart function to a near normal pre-MI level.4 As with any functional tissue, successful regeneration of cardiac tissue involves the proper delivery of multiple cell types with environmental cues favoring integration and survival of the implanted cell/tissue graft. Engineered tissues should address multiple parameters including: soluble signals, cell-to-cell interactions, and matrix materials evaluated as delivery vehicles, their effects on cell survival, material strength, and facilitation of cell-to-tissue organization. Studies employing the direct injection of graft cells only ignore these essential elements.2,5,6 A tissue design combining these ingredients has yet to be developed. Here, we present an example of integrated designs using layering of patterned cell sheets with two distinct types of biological-derived materials containing the target organ cell type and endothelial cells for enhancing new vessels formation in the “tissue”. Although these studies focus on the generation of heart-like tissue, this tissue design can be applied to many organs other than heart with minimal design and material changes, and is meant to be an off-the-shelf product for regenerative therapies. The protocol contains five detailed steps. A temperature sensitive Poly(N-isopropylacrylamide) (pNIPAAM) is used to coat tissue culture dishes. Then, tissue specific cells are cultured on the surface of the coated plates/micropattern surfaces to form cell sheets with strong lateral adhesions. Thirdly, a base matrix is created for the tissue by combining porous matrix with neovascular permissive hydrogels and endothelial cells. Finally, the cell sheets are lifted

  3. Biological advantages of porous hydroxyapatite scaffold made by solid freeform fabrication for bone tissue regeneration.

    PubMed

    Kwon, Byeong-Ju; Kim, Jungsung; Kim, Yong Hwa; Lee, Mi Hee; Baek, Hyun Sook; Lee, Dae Hyung; Kim, Hye-Lee; Seo, Hyok Jin; Lee, Min Hyeon; Kwon, Soon-Young; Koo, Min-Ah; Park, Jong-Chul

    2013-07-01

    Presently, commercially available porous bone substitutes are manufactured by the sacrificial template method, direct foaming method, and polymer replication method (PRM). However, current manufacturing methods provide only the simplest form of the bone scaffold and cannot easily control pore size. Recent developments in medical imaging technology, computer-aided design, and solid freeform fabrication (SFF), have made it possible to accurately produce porous synthetic bone scaffolds to fit the defected bone shape. Porous scaffolds were fabricated by SFF and PRM for a comparison of physical and mechanical properties of scaffold. The suggested three-dimensional model has interconnected cubic pores of 500 μm and its calculated porosity is 25%. Whereas hydroxyapatite scaffolds fabricated by SFF had connective macropores, those by PRM formed a closed pore external surface with internally interconnected pores. SFF was supposed to be a proper method for fabricating an interconnected macroporous network. Biocompatibility was confirmed by testing the cytotoxicity, hemolysis, irritation, sensitization, and implantation. In summary, the aim was to verify the safety and efficacy of the scaffolds by biomechanical and biological tests with the hope that this research could promote the feasibility of using the scaffolds as a bone substitute.

  4. Porous bioactive scaffold of aliphatic polyurethane and hydroxyapatite for tissue regeneration.

    PubMed

    Wang, Li; Li, Yubao; Zuo, Yi; Zhang, Li; Zou, Qin; Cheng, Lin; Jiang, Hong

    2009-04-01

    In this study, a new hydroxyapatite (HA)/polyurethane (PU) composite porous scaffold was developed by in situ polymerization. Aliphatic isophorone diisocyanate as a nontoxic and safe agent was adopted to produce the rigid segment in polyurethane polymerization. Hydroxyapatite powder was compounded in a PU polymer matrix during the polymeric process. The macrostructure and morphology as well as mechanical strength of the scaffolds were characterized by FTIR, XRD, DSC and SEM. The results show that the isophorone diisocyanate can react mildly with hydroxyl (-OH) groups of castor oil and a mild foaming action caused by the release of CO2 gas occurred simultaneously in the reactive process, thus producing a uniform porous structure of HA/PU scaffold. The HA/PU composite scaffold with a high HA content of about 60 wt% has a porosity of more than 78% and a pore size from 100 microm to 800 microm. The HA/PU scaffold exhibited good cytocompatibility estimated by co-culturing the scaffold with MG63 cells through MTT test. The porous composite scaffold has good homogenization and a perfect three-dimensional structure for cell migration and bone tissue ingrowth, and should have good prospects for bone tissue regeneration. PMID:19208942

  5. Fabrication of Porous α-TCP/Gellan Gum Scaffold for Bone Tissue Engineering.

    PubMed

    Wen, Jian; Kim, Ill Yong; Kikuta, Koichi; Ohtsuki, Chikara

    2016-03-01

    α-tricalcium phosphate (α-TCP, α-Ca3(PO4)2) receives great attention for bone repairing due to its biodegradability and capability of transformation to human bone's main inorganic components, hydroxyapatite (HAp). α-TCP porous scaffold is easily procurable by sintering of the low-temperature polymorph of TCP, β-TCR Still, porous body of α-TCP is too brittle to being handled and shaped, limiting its clinical application as implant materials. To improve mechanical properties of α-TCP porous scaffold, the present study focused on coating of a type of polysaccharides on α-TCP scaffolds. Gellan gum was chosen as the polysaccharide for coating because of its biodegradability as well as the potential acting as substrate for HAp deposition during hydration of α-TCP after exposure to body fluid. After coating of gellan gum on α-TCP scaffolds with porosity of 75 vol%, the compressive strength increased from 0.45 MPa to around 2.00 MPa. Among the coated scaffold, the maximum compressive strength, 3.97 MPa, was obtained on the scaffold with porosity of 63 vol%. Improvement of mechanical properties of α-TCP/gellan gum composites was achieved to show easy handling performance for a bone substitute for tissue repairing. The dissolving rate of the coated scaffolds was also controlled by adjusting the concentration of GG solutions. PMID:27455764

  6. Repair of mandibular defects using MSCs-seeded biodegradable polyester porous scaffolds.

    PubMed

    Ren, Jie; Ren, Tianbin; Zhao, Peng; Huang, Yanxia; Pan, Kefeng

    2007-01-01

    PLLA, PLA-PEG and PLGA porous scaffolds with pore size ranging from 100 to 250 microm and porosity over 85% were fabricated by a solution-casting/salt-leaching method. The porous structure and porosity of the scaffold were mainly dependent on volume fraction and size of the porogens of NaCl particles. The effects of the polymeric materials on the cell culture behavior and bone formation in vitro in their scaffolds were studied. In vitro cell culture in the scaffolds of the three polymers demonstrated that mesenchymal stem cells (MSCs) had a good adhesion and spread. The composite matrixes cultured for several days possessed preliminary functions of tissue-engineering bone, with signs of the calcium knur formation and the expression of osteocalcin and collagen I in mRNA, especially that of PLA-PEG and PLGA. These cell-loaded porous scaffolds showed effective repair of mandibular defect of rabbits in vivo. Contrastive experiments demonstrated that the MSCs/PLGA scaffold owned better ability facilitating for the MSCs proliferation, differentiation and defect repair. These composite scaffolds can be a potential effective tool for treating mandibular and other bone defects. PMID:17550655

  7. Growth of continuous bonelike mineral within porous poly(lactide-co-glycolide) scaffolds in vitro.

    PubMed

    Murphy, W L; Kohn, D H; Mooney, D J

    2000-04-01

    Strategies to engineer bone have focused on the use of natural or synthetic degradable materials as scaffolds for cell transplantation or as substrates to guide bone regeneration. The basic requirements of the scaffold material are biocompatibility, degradability, mechanical integrity, and osteoconductivity. A major design problem is satisfying each of these requirements with a single scaffold material. This study addresses this problem by describing an approach to combine the biocompatibility and degradability of a polymer scaffold with the osteoconductivity and mechanical reinforcement of a bonelike mineral film. We report the nucleation and growth of a continuous carbonated apatite mineral on the interior pore surfaces of a porous, degradable polymer scaffold via a one step, room temperature incubation process. A 3-dimensional, porous scaffold of the copolymer 85:15 poly(lactide-co-glycolide) was fabricated by a solvent casting, particulate leaching process. Fourier transform IR spectroscopy and scanning electron microscopy (SEM) analysis after different incubation times in a simulated body fluid (SBF) demonstrate the growth of a continuous bonelike apatite layer within the pores of the polymer scaffold. Quantification of phosphate on the scaffold displays the growth and development of the mineral film over time with an incorporation of 0.43 mg of phosphate (equivalent to 0.76 mg of hydroxyapatite) per scaffold after 14 days in SBF. The compressive moduli of polymer scaffolds increased fivefold with formation of a mineral film after a 16-day incubation time as compared to control scaffolds. In summary, this biomimetic treatment provides a simple, one step, room temperature method for surface functionalization and subsequent mineral nucleation and growth on biodegradable polymer scaffolds for tissue engineering.

  8. Oxygen- and Nitrogen-Enriched 3D Porous Carbon for Supercapacitors of High Volumetric Capacity.

    PubMed

    Li, Jia; Liu, Kang; Gao, Xiang; Yao, Bin; Huo, Kaifu; Cheng, Yongliang; Cheng, Xiaofeng; Chen, Dongchang; Wang, Bo; Sun, Wanmei; Ding, Dong; Liu, Meilin; Huang, Liang

    2015-11-11

    Efficient utilization and broader commercialization of alternative energies (e.g., solar, wind, and geothermal) hinges on the performance and cost of energy storage and conversion systems. For now and in the foreseeable future, the combination of rechargeable batteries and electrochemical capacitors remains the most promising option for many energy storage applications. Porous carbonaceous materials have been widely used as an electrode for batteries and supercapacitors. To date, however, the highest specific capacitance of an electrochemical double layer capacitor is only ∼200 F/g, although a wide variety of synthetic approaches have been explored in creating optimized porous structures. Here, we report our findings in the synthesis of porous carbon through a simple, one-step process: direct carbonization of kelp in an NH3 atmosphere at 700 °C. The resulting oxygen- and nitrogen-enriched carbon has a three-dimensional structure with specific surface area greater than 1000 m(2)/g. When evaluated as an electrode for electrochemical double layer capacitors, the porous carbon structure demonstrated excellent volumetric capacitance (>360 F/cm(3)) with excellent cycling stability. This simple approach to low-cost carbonaceous materials with unique architecture and functionality could be a promising alternative to fabrication of porous carbon structures for many practical applications, including batteries and fuel cells.

  9. Oxygen- and Nitrogen-Enriched 3D Porous Carbon for Supercapacitors of High Volumetric Capacity.

    PubMed

    Li, Jia; Liu, Kang; Gao, Xiang; Yao, Bin; Huo, Kaifu; Cheng, Yongliang; Cheng, Xiaofeng; Chen, Dongchang; Wang, Bo; Sun, Wanmei; Ding, Dong; Liu, Meilin; Huang, Liang

    2015-11-11

    Efficient utilization and broader commercialization of alternative energies (e.g., solar, wind, and geothermal) hinges on the performance and cost of energy storage and conversion systems. For now and in the foreseeable future, the combination of rechargeable batteries and electrochemical capacitors remains the most promising option for many energy storage applications. Porous carbonaceous materials have been widely used as an electrode for batteries and supercapacitors. To date, however, the highest specific capacitance of an electrochemical double layer capacitor is only ∼200 F/g, although a wide variety of synthetic approaches have been explored in creating optimized porous structures. Here, we report our findings in the synthesis of porous carbon through a simple, one-step process: direct carbonization of kelp in an NH3 atmosphere at 700 °C. The resulting oxygen- and nitrogen-enriched carbon has a three-dimensional structure with specific surface area greater than 1000 m(2)/g. When evaluated as an electrode for electrochemical double layer capacitors, the porous carbon structure demonstrated excellent volumetric capacitance (>360 F/cm(3)) with excellent cycling stability. This simple approach to low-cost carbonaceous materials with unique architecture and functionality could be a promising alternative to fabrication of porous carbon structures for many practical applications, including batteries and fuel cells. PMID:26477268

  10. Novel chemical scaffolds of the tumor marker AKR1B10 inhibitors discovered by 3D QSAR pharmacophore modeling

    PubMed Central

    Kumar, Raj; Son, Minky; Bavi, Rohit; Lee, Yuno; Park, Chanin; Arulalapperumal, Venkatesh; Cao, Guang Ping; Kim, Hyong-ha; Suh, Jung-keun; Kim, Yong-seong; Kwon, Yong Jung; Lee, Keun Woo

    2015-01-01

    Aim: Recent evidence suggests that aldo-keto reductase family 1 B10 (AKR1B10) may be a potential diagnostic or prognostic marker of human tumors, and that AKR1B10 inhibitors offer a promising choice for treatment of many types of human cancers. The aim of this study was to identify novel chemical scaffolds of AKR1B10 inhibitors using in silico approaches. Methods: The 3D QSAR pharmacophore models were generated using HypoGen. A validated pharmacophore model was selected for virtual screening of 4 chemical databases. The best mapped compounds were assessed for their drug-like properties. The binding orientations of the resulting compounds were predicted by molecular docking. Density functional theory calculations were carried out using B3LYP. The stability of the protein-ligand complexes and the final binding modes of the hit compounds were analyzed using 10 ns molecular dynamics (MD) simulations. Results: The best pharmacophore model (Hypo 1) showed the highest correlation coefficient (0.979), lowest total cost (102.89) and least RMSD value (0.59). Hypo 1 consisted of one hydrogen-bond acceptor, one hydrogen-bond donor, one ring aromatic and one hydrophobic feature. This model was validated by Fischer's randomization and 40 test set compounds. Virtual screening of chemical databases and the docking studies resulted in 30 representative compounds. Frontier orbital analysis confirmed that only 3 compounds had sufficiently low energy band gaps. MD simulations revealed the binding modes of the 3 hit compounds: all of them showed a large number of hydrogen bonds and hydrophobic interactions with the active site and specificity pocket residues of AKR1B10. Conclusion: Three compounds with new structural scaffolds have been identified, which have stronger binding affinities for AKR1B10 than known inhibitors. PMID:26051108

  11. Preparation and characterization of nano-hydroxyapatite/silk fibroin porous scaffolds.

    PubMed

    Liu, Lin; Liu, Jinying; Wang, Mingqi; Min, Sijia; Cai, Yurong; Zhu, Liangjun; Yao, Juming

    2008-01-01

    Novel tissue engineering scaffold materials of nano-hydroxyapatite (nHA)/silk fibroin (SF) biocomposite were prepared by freeze-drying. The needle-like nHA crystals of about 10 nm in diameter by 50-80 nm in length, which were uniformly distributed in the porous nHA/SF scaffolds, were prepared by a co-precipitation method with a size. The as-prepared nHA/SF scaffolds showed good homogeneity, interconnected pores and high porosity. XRD and FT-IR analysis suggested that the silk fibroin was in beta-sheet structure, which usually provides outstanding mechanical properties for silk materials. In this work, composite scaffolds containing as high as 70% (w/w) nHA were prepared, which had excellent compressive modulus and strength, higher than the scaffolds at low nHA content level and other porous biodegradable polymeric scaffolds often considered in bone-related tissue engineering reported previously. The cell compatibility of composite scaffolds was evaluated through cell viability by MTT assay. All these results indicated that these nHA/SF scaffold materials may be a promising biomaterial for bone tissue engineering.

  12. Development of Composite Porous Scaffolds Based on Collagen and Biodegradable Poly(ester urethane)urea

    PubMed Central

    Guan, Jianjun; Stankus, John J.; Wagner, William R.

    2010-01-01

    Our objective in this work was to develop a flexible, biodegradable scaffold for cell transplantation that would incorporate a synthetic component for strength and flexibility and type I collagen for enzymatic lability and cytocompatibility. A biodegradable poly(ester urethane)urea was synthesized from poly(caprolactone), 1,4-diisocyanatobutane, and putrescine. Using a thermally induced phase separation process, porous scaffolds were created from a mixture containing this polyurethane and 0%, 10%, 20%, or 30% type I collagen. The resulting scaffolds were found to have open, interconnected pores (from 7 to >100 um) and porosities from 58% to 86% depending on the polyurethane/collagen ratio. The scaffolds were also flexible with breaking strains of 82–443% and tensile strengths of 0.97–4.11 MPa depending on preparation conditions. Scaffold degradation was significantly increased when collagenase was introduced into an incubating buffer in a manner that was dependent on the mass fraction of collagen present in the scaffold. Mass losses could be varied from 15% to 59% over 8 weeks. When culturing umbilical artery smooth muscle cells on these scaffolds higher cell numbers were observed over a 4-week culture period in scaffolds containing collagen. In summary, a strong and flexible scaffold system has been developed that can degrade by both hydrolysis and collagenase degradation pathways, as well as support cell growth. This scaffold possesses properties that would make it attractive for future use in soft tissue applications where such mechanical and biological features would be advantageous. PMID:16826792

  13. Osteoinduction and survival of osteoblasts and bone-marrow stromal cells in 3D biphasic calcium phosphate scaffolds under static and dynamic culture conditions.

    PubMed

    Rath, Subha N; Strobel, Leonie A; Arkudas, Andreas; Beier, Justus P; Maier, Anne-Kathrin; Greil, Peter; Horch, Raymund E; Kneser, Ulrich

    2012-10-01

    In many tissue engineering approaches, the basic difference between in vitro and in vivo conditions for cells within three-dimensional (3D) constructs is the nutrition flow dynamics. To achieve comparable results in vitro, bioreactors are advised for improved cell survival, as they are able to provide a controlled flow through the scaffold. We hypothesize that a bioreactor would enhance long-term differentiation conditions of osteogenic cells in 3D scaffolds. To achieve this either primary rat osteoblasts or bone marrow stromal cells (BMSC) were implanted on uniform-sized biphasic calcium phosphate (BCP) scaffolds produced by a 3D printing method. Three types of culture conditions were applied: static culture without osteoinduction (Group A); static culture with osteoinduction (Group B); dynamic culture with osteoinduction (Group C). After 3 and 6 weeks, the scaffolds were analysed by alkaline phosphatase (ALP), dsDNA amount, SEM, fluorescent labelled live-dead assay, and real-time RT-PCR in addition to weekly alamarBlue assays. With osteoinduction, increased ALP values and calcium deposition are observed; however, under static conditions, a significant decrease in the cell number on the biomaterial is observed. Interestingly, the bioreactor system not only reversed the decreased cell numbers but also increased their differentiation potential. We conclude from this study that a continuous flow bioreactor not only preserves the number of osteogenic cells but also keeps their differentiation ability in balance providing a suitable cell-seeded scaffold product for applications in regenerative medicine.

  14. Electrospun carbon nanofibers reinforced 3D porous carbon polyhedra network derived from metal-organic frameworks for capacitive deionization.

    PubMed

    Liu, Yong; Ma, Jiaqi; Lu, Ting; Pan, Likun

    2016-01-01

    Carbon nanofibers reinforced 3D porous carbon polyhedra network (e-CNF-PCP) was prepared through electrospinning and subsequent thermal treatment. The morphology, structure and electrochemical performance of the e-CNF-PCP were characterized using scanning electron microscopy, Raman spectra, nitrogen adsorption-desorption, cyclic voltammetry and electrochemical impedance spectroscopy, and their electrosorption performance in NaCl solution was studied. The results show that the e-CNF-PCP exhibits a high electrosorption capacity of 16.98 mg g(-1) at 1.2 V in 500 mg l(-1) NaCl solution, which shows great improvement compared with those of electrospun carbon nanofibers and porous carbon polyhedra. The e-CNF-PCP should be a very promising candidate as electrode material for CDI applications. PMID:27608826

  15. Electrospun carbon nanofibers reinforced 3D porous carbon polyhedra network derived from metal-organic frameworks for capacitive deionization

    PubMed Central

    Liu, Yong; Ma, Jiaqi; Lu, Ting; Pan, Likun

    2016-01-01

    Carbon nanofibers reinforced 3D porous carbon polyhedra network (e-CNF-PCP) was prepared through electrospinning and subsequent thermal treatment. The morphology, structure and electrochemical performance of the e-CNF-PCP were characterized using scanning electron microscopy, Raman spectra, nitrogen adsorption-desorption, cyclic voltammetry and electrochemical impedance spectroscopy, and their electrosorption performance in NaCl solution was studied. The results show that the e-CNF-PCP exhibits a high electrosorption capacity of 16.98 mg g−1 at 1.2 V in 500 mg l−1 NaCl solution, which shows great improvement compared with those of electrospun carbon nanofibers and porous carbon polyhedra. The e-CNF-PCP should be a very promising candidate as electrode material for CDI applications. PMID:27608826

  16. Electrospun carbon nanofibers reinforced 3D porous carbon polyhedra network derived from metal-organic frameworks for capacitive deionization

    NASA Astrophysics Data System (ADS)

    Liu, Yong; Ma, Jiaqi; Lu, Ting; Pan, Likun

    2016-09-01

    Carbon nanofibers reinforced 3D porous carbon polyhedra network (e-CNF-PCP) was prepared through electrospinning and subsequent thermal treatment. The morphology, structure and electrochemical performance of the e-CNF-PCP were characterized using scanning electron microscopy, Raman spectra, nitrogen adsorption-desorption, cyclic voltammetry and electrochemical impedance spectroscopy, and their electrosorption performance in NaCl solution was studied. The results show that the e-CNF-PCP exhibits a high electrosorption capacity of 16.98 mg g‑1 at 1.2 V in 500 mg l‑1 NaCl solution, which shows great improvement compared with those of electrospun carbon nanofibers and porous carbon polyhedra. The e-CNF-PCP should be a very promising candidate as electrode material for CDI applications.

  17. Electroactive Film of Myoglobin Incorporated in a 3D-porous Calcium Alginate Film with Polyvinyl Alcohol, Glycerin and Gelatin.

    PubMed

    Zheng, Xueqin; Sun, Hong; Hou, Shifeng

    2015-01-01

    In this work, an electroactive porous Mb-CA's composite film was fabricated by incorporating myoglobin (Mb) in a three-dimension (3D) porous calcium alginate (CA) film with polyvinyl alcohol, glycerol, and gelatin. The porous Mb-CA's film modified electrodes exhibited a pair of well-defined, quasi-reversible cyclic voltammetric (CV) peaks at about -0.37 V vs. SCE in pH 7.0 buffers, characteristic of Mb heme Fe((III))/Fe((II)) redox couples. The electrochemical parameters, such as formal potentials (E(o')) and apparent heterogeneous electron-transfer rate constants (ks), were estimated by square-wave voltammetry with nonlinear regression analysis. The porous CA's composite film could form hydrogel in aqueous solution. The positions of the Soret absorbance band suggest that Mb in the CA's composite film kept its native states in the medium pH range. Hydrogen peroxide, oxygen, and nitrite were electrochemically catalyzed by the Mb-CA's composite film with significant lowering of the reduction overpotential.

  18. The generation of biomolecular patterns in highly porous collagen-GAG scaffolds using direct photolithography.

    PubMed

    Martin, Teresa A; Caliari, Steven R; Williford, Paul D; Harley, Brendan A; Bailey, Ryan C

    2011-06-01

    The extracellular matrix (ECM) is a complex organization of structural proteins found within tissues and organs. Heterogeneous tissues with spatially and temporally modulated properties play an important role in organism physiology. Here we present a benzophenone (BP) based direct, photolithographic approach to spatially pattern solution phase biomolecules within collagen-GAG (CG) scaffolds and demonstrate creation of a wide range of patterns composed of multiple biomolecular species in a manner independent from scaffold fabrication steps. We demonstrate the ability to immobilize biomolecules at surface densities of up to 1000 ligands per square micron on the scaffold strut surface and to depths limited by the penetration depth of the excitation source into the scaffold structure. Importantly, while BP photopatterning does further crosslink the CG scaffold, evidenced by increased mechanical properties and collagen crystallinity, it does not affect scaffold microstructural or compositional properties or negatively influence cell adhesion, viability, or proliferation. We show that covalently photoimmobilized fibronectin within a CG scaffold significantly increases the speed of MC3T3-E1 cell attachment relative to the bare CG scaffold or non-specifically adsorbed fibronectin, suggesting that this approach can be used to improve scaffold bioactivity. Our findings, on the whole, establish the use of direct, BP photolithography as a methodology for covalently incorporating activity-improving biochemical cues within 3D collagen biomaterial scaffolds with spatial control over biomolecular deposition.

  19. Internal structures of scaffold-free 3D cell cultures visualized by synchrotron radiation-based micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Saldamli, Belma; Herzen, Julia; Beckmann, Felix; Tübel, Jutta; Schauwecker, Johannes; Burgkart, Rainer; Jürgens, Philipp; Zeilhofer, Hans-Florian; Sader, Robert; Müller, Bert

    2008-08-01

    Recently the importance of the third dimension in cell biology has been better understood, resulting in a re-orientation towards three-dimensional (3D) cultivation. Yet adequate tools for their morphological characterization have to be established. Synchrotron radiation-based micro computed tomography (SRμCT) allows visualizing such biological systems with almost isotropic micrometer resolution, non-destructively. We have applied SRμCT for studying the internal morphology of human osteoblast-derived, scaffold-free 3D cultures, termed histoids. Primary human osteoblasts, isolated from femoral neck spongy bone, were grown as 2D culture in non-mineralizing osteogenic medium until a rather thick, multi-cellular membrane was formed. This delicate system was intentionally released to randomly fold itself. The folded cell cultures were grown to histoids of cubic milli- or centimeter size in various combinations of mineralizing and non-mineralizing osteogenic medium for a total period of minimum 56 weeks. The SRμCT-measurements were performed in the absorption contrast mode at the beamlines BW 2 and W 2 (HASYLAB at DESY, Hamburg, Germany), operated by the GKSS-Research Center. To investigate the entire volume of interest several scans were performed under identical conditions and registered to obtain one single dataset of each sample. The histoids grown under different conditions exhibit similar external morphology of globular or ovoid shape. The SRμCT-examination revealed the distinctly different morphological structures inside the histoids. One obtains details of the histoids that permit to identify and select the most promising slices for subsequent histological characterization.

  20. Development of poly(vinyl alcohol) porous scaffold with high strength and well ciprofloxacin release efficiency.

    PubMed

    Zhou, Xue-Hua; Wei, Dai-Xu; Ye, Hai-Mu; Zhang, Xiaocan; Meng, Xiaoyu; Zhou, Qiong

    2016-10-01

    Hydrophilic porous polymer scaffolds have shown great application in drug controlled release, while their mechanical properties and release efficiency still need further improvement. In the current study, the porous scaffolds of polyvinyl alcohol (PVA) prepared by quenching in liquid nitrogen and freeze drying method from different original concentration aqueous solutions were fabricated. Among different PVA scaffolds, the scaffold stemming from 18wt.% PVA aqueous solution exhibited the best mechanical properties, 10.5 and 1.54MPa tensile strengths for the dry and hydrogel states respectively. The inner morphology of such PVA scaffold was unidirectional honeycomb-like structure with average microchannel section of 0.5μm, and the scaffold showed porosity of 71% and rather low ciprofloxacin (Cip) release efficiency of 54.5%. Then poly(ethylene glycol) (PEG) was incorporated to enhance the Cip release efficiency. The release efficiency reached 89.3% after introducing 10wt.% PEG, and the mechanical properties of scaffold decreased slightly. Various characterization methods demonstrated that, adding PEG could help to enlarge the microchannel, create extra holes on the channel walls, weaken the interaction between PVA chains and Cip, and miniaturize the crystal size of Cip. All these effects benefit the dissolution and diffusion of Cip from scaffold, increasing its release capability. Moreover, based on biocompatible material composition, PVA/PEG scaffold is a non-cytotoxicity and have been verified that it can promote cell growth. And PVA/PEG scaffolds loaded with Cip can completely inhibit the growth of microorganism because of Cip sustaining release. The PVA scaffold would have a good potential application in tissue engineering, demanding high strength and well drug release capability.

  1. Ectopic bone formation by 3D porous calcium phosphate-Ti6Al4V hybrids produced by perfusion electrodeposition.

    PubMed

    Chai, Yoke Chin; Kerckhofs, Greet; Roberts, Scott J; Van Bael, Simon; Schepers, Evert; Vleugels, Jozef; Luyten, Frank P; Schrooten, Jan

    2012-06-01

    Successful clinical repair of non-healing skeletal defects requires the use of bone substitutes with robust bone inductivity and excellent biomechanical stability. Thus, three-dimensionally functionalised porous calcium phosphate-Ti6Al4V (CaP-Ti) hybrids were produced by perfusion electrodeposition, and the in vitro and in vivo biological performances were evaluated using human periosteum derived cells (hPDCs). By applying various current densities at the optimised deposition conditions, CaP coatings with sub-micrometer to nano-scale porous crystalline structures and different ion dissolution kinetics were deposited on the porous Ti6Al4V scaffolds. These distinctive physicochemical properties caused a significant impact on in vitro proliferation, osteogenic differentiation, and matrix mineralisation of hPDCs. This includes a potential role of hPDCs in mediating osteoclastogenesis for the resorption of CaP coatings, as indicated by a significant down-regulation of osteoprotegerin (OPG) gene expression and by the histological observation of abundant multi-nucleated giant cells near to the coatings. By subcutaneous implantation, the produced hybrids induced ectopic bone formation, which was highly dependent on the physicochemical properties of the CaP coating (including the Ca(2+) dissolution kinetics and coating surface topography), in a cell density-dependent manner. This study provided further insight on stem cell-CaP biomaterial interactions, and the feasibility to produced bone reparative units that are predictively osteoinductive in vivo by perfusion electrodeposition technology.

  2. Label-free magnetic resonance imaging to locate live cells in three-dimensional porous scaffolds

    PubMed Central

    Abarrategi, A.; Fernandez-Valle, M. E.; Desmet, T.; Castejón, D.; Civantos, A.; Moreno-Vicente, C.; Ramos, V.; Sanz-Casado, J. V.; Martínez-Vázquez, F. J.; Dubruel, P.; Miranda, P.; López-Lacomba, J. L.

    2012-01-01

    Porous scaffolds are widely tested materials used for various purposes in tissue engineering. A critical feature of a porous scaffold is its ability to allow cell migration and growth on its inner surface. Up to now, there has not been a method to locate live cells deep inside a material, or in an entire structure, using real-time imaging and a non-destructive technique. Herein, we seek to demonstrate the feasibility of the magnetic resonance imaging (MRI) technique as a method to detect and locate in vitro non-labelled live cells in an entire porous material. Our results show that the use of optimized MRI parameters (4.7 T; repetition time = 3000 ms; echo time = 20 ms; resolution 39 × 39 µm) makes it possible to obtain images of the scaffold structure and to locate live non-labelled cells in the entire material, with a signal intensity higher than that obtained in the culture medium. In the current study, cells are visualized and located in different kinds of porous scaffolds. Moreover, further development of this MRI method might be useful in several three-dimensional biomaterial tests such as cell distribution studies, routine qualitative testing methods and in situ monitoring of cells inside scaffolds. PMID:22442095

  3. Degradation and biocompatibility of porous nano-hydroxyapatite/polyurethane composite scaffold for bone tissue engineering

    NASA Astrophysics Data System (ADS)

    Dong, Zhihong; Li, Yubao; Zou, Qin

    2009-04-01

    Porous scaffold containing 30 wt% nano-hydroxyapatite (n-HA) and 70 wt% polyurethane (PU) from castor oil was prepared by a foaming method and investigated by X-ray diffraction (XRD), Fourier transform infrared absorption (FTIR), scanning electron microscopy (SEM) techniques. The results show that n-HA particles disperse homogeneously in the PU matrix. The porous scaffold has not only macropores of 100-800 μm in size but also a lot of micropores on the walls of macropores. The porosity and compressive strength of scaffold are 80% and 271 kPa, respectively. After soaking in simulated body fluid (SBF), hydrolysis and deposition partly occur on the scaffold. The biological evaluation in vitro and in vivo shows that the n-HA/PU scaffold is non-cytotoxic and degradable. The porous structure provides a good microenvironment for cell adherence, growth and proliferation. The n-HA/PU composite scaffold can be satisfied with the basic requirement for tissue engineering, and has the potential to be applied in repair and substitute of human menisci of the knee-joint and articular cartilage.

  4. Fabrication of three-dimensional nano, micro and micro/nano scaffolds of porous poly(lactic acid) by electrospinning and comparison of cell infiltration by Z-stacking/three-dimensional projection technique.

    PubMed

    Shalumon, K T; Chennazhi, K P; Tamura, H; Kawahara, K; Nair, S V; Jayakumar, R

    2012-03-01

    The use of electrospun extracellular matrix (ECM)-mimicking nanofibrous scaffolds for tissue engineering is limited by poor cellular infiltration. The authors hypothesised that cell penetration could be enhanced in scaffolds by using a hierarchical structure where nano fibres are combined with micron-scale fibres while preserving the overall scaffold architecture. To assess this, we fabricated electrospun porous poly(lactic acid) (PLA) scaffolds having nanoscale, microscale and combined micro/nano architecture and evaluated the structural characteristics and biological response in detail. Although the bioactivity was intermediate to that for nanofibre and microfibre scaffold, a unique result of this study was that the micro/nano combined fibrous scaffold showed improved cell infiltration and distribution than the nanofibrous scaffold. Although the cells were found to be lining the scaffold periphery in the case of nanofibrous scaffold, micro/nano scaffolds had cells dispersed throughout the scaffold. Further, as expected, the addition of nanoparticles of hydroxyapatite (nHAp) improved the bioactivity, although it did not play a significant role in cell penetration. Thus, this strategy of creating a three-dimensional (3D) micro/nano architecture that would increase the porosity of the fibrous scaffold and thereby improving the cell penetration, can be utilised for the generation of functional tissue engineered constructs in vitro.

  5. Use of 3D cartilage scaffolds for the stabilization of implants and bone regeneration with the fit-lock technique.

    PubMed

    Falisi, Giovanni; Galli, Massimo; Vittorini-Velasquez, Pedro; Gallegos-Rivera, Juan C; Minasi, Roberto; De Biase, Alberto; Di Paolo, Carlo

    2013-01-01

    The surgical procedures for implant applications on the lateral-upper areas depend on sinus pneumatization and availability of the residual bone. In these cases, autologous bone grafting remains the gold standard. Nevertheless, because of the morbidity associated to the donor site and the post-surgical complications, several alternative bone substitutes have been introduced, which, however, imply additional costs and show limited osteoinductive properties. Such limitations can be compensated with new regeneration strategies for biological and mechanical tissue restoration, a subject which has been addressed by tissue engineering in recent years. The authors present a new therapeutic option for implant application in the upper maxilla with bone availability less than 4 mm by using 3D scaffolds obtained from antigen-free porcine cartilage in the fit-lock technique. A longitudinal study on 18 consecutive cases was performed, with a 95.2% success rate one year after the implant. The advantages of this new technique are: 1) Functional and anatomical recovery of the maxillary antrum, 2) Immediate application of the implants; 3) Reduction of surgical times; 4) Absence of patient morbidity; 5) Local anesthesia; 6) Use of implants with a diameter > 4 mm.

  6. Real-time 3D imaging of Haines jumps in porous media flow

    PubMed Central

    Berg, Steffen; Ott, Holger; Klapp, Stephan A.; Schwing, Alex; Neiteler, Rob; Brussee, Niels; Makurat, Axel; Leu, Leon; Enzmann, Frieder; Schwarz, Jens-Oliver; Kersten, Michael; Irvine, Sarah; Stampanoni, Marco

    2013-01-01

    Newly developed high-speed, synchrotron-based X-ray computed microtomography enabled us to directly image pore-scale displacement events in porous rock in real time. Common approaches to modeling macroscopic fluid behavior are phenomenological, have many shortcomings, and lack consistent links to elementary pore-scale displacement processes, such as Haines jumps and snap-off. Unlike the common singular pore jump paradigm based on observations of restricted artificial capillaries, we found that Haines jumps typically cascade through 10–20 geometrically defined pores per event, accounting for 64% of the energy dissipation. Real-time imaging provided a more detailed fundamental understanding of the elementary processes in porous media, such as hysteresis, snap-off, and nonwetting phase entrapment, and it opens the way for a rigorous process for upscaling based on thermodynamic models. PMID:23431151

  7. Tailoring properties of porous Poly (vinylidene fluoride) scaffold through nano-sized 58s bioactive glass.

    PubMed

    Shuai, Cijun; Huang, Wei; Feng, Pei; Gao, Chengde; Shuai, Xiong; Xiao, Tao; Deng, Youwen; Peng, Shuping; Wu, Ping

    2016-01-01

    The biological properties of porous poly (vinylidene fluoride) (PVDF) scaffolds fabricated by selective laser sintering were tailored through nano-sized 58s bioactive glass. The results showed that 58s bioactive glass distributed evenly in the PVDF matrix. There were some exposed particles on the surface which provided attachment sites for biological response. It was confirmed that the scaffolds had highly bioactivity by the formation of bone-like apatite in simulated body fluid. And the bone-like apatite became dense with the increase in 58s bioactive glass and culture time. Moreover, the scaffolds were suitable for cell adhesion and proliferation compared with the PVDF scaffolds without 58s bioactive glass. The research showed that the PVDF/58s bioactive glass scaffolds had latent application in bone tissue engineering. PMID:26592544

  8. Tailoring properties of porous Poly (vinylidene fluoride) scaffold through nano-sized 58s bioactive glass.

    PubMed

    Shuai, Cijun; Huang, Wei; Feng, Pei; Gao, Chengde; Shuai, Xiong; Xiao, Tao; Deng, Youwen; Peng, Shuping; Wu, Ping

    2016-01-01

    The biological properties of porous poly (vinylidene fluoride) (PVDF) scaffolds fabricated by selective laser sintering were tailored through nano-sized 58s bioactive glass. The results showed that 58s bioactive glass distributed evenly in the PVDF matrix. There were some exposed particles on the surface which provided attachment sites for biological response. It was confirmed that the scaffolds had highly bioactivity by the formation of bone-like apatite in simulated body fluid. And the bone-like apatite became dense with the increase in 58s bioactive glass and culture time. Moreover, the scaffolds were suitable for cell adhesion and proliferation compared with the PVDF scaffolds without 58s bioactive glass. The research showed that the PVDF/58s bioactive glass scaffolds had latent application in bone tissue engineering.

  9. Collagen/chitosan porous bone tissue engineering composite scaffold incorporated with Ginseng compound K.

    PubMed

    Muthukumar, Thangavelu; Aravinthan, Adithan; Sharmila, Judith; Kim, Nam Soo; Kim, Jong-Hoon

    2016-11-01

    In this study, suitable scaffold materials for bone tissue engineering were successfully prepared using fish scale collagen, hydroxyapatite, chitosan, and beta-tricalcium phosphate. Porous composite scaffolds were prepared by freeze drying method. The Korean traditional medicinal ginseng compound K, a therapeutic agent for the treatment of osteoporosis that reduces inflammation and enhances production of bone morphogenetic protein-2, was incorporated into the composite scaffold. The scaffold was characterized for pore size, swelling, density, degradation, mineralization, cell viability and attachment, and its morphological features were examined using scanning electron microscopy. This characterization and in vitro analysis showed that the prepared scaffold was biocompatible and supported the growth of MG-63 cells, and therefore has potential as an alternative approach for bone regeneration. PMID:27516305

  10. Silver nanoparticle studded porous polyethylene scaffolds: bacteria struggle to grow on them while mammalian cells thrive.

    PubMed

    D'Britto, Virginia; Kapse, Harsha; Babrekar, Harshada; Prabhune, A A; Bhoraskar, S V; Premnath, V; Prasad, B L V

    2011-07-01

    Silver nanoparticle studded scaffolds were prepared by exploiting the Ag(+) ion reducing activity of sophorolipids--a class of 'glycolipids' that cap the ensuing nanoparticles as well. To achieve this, the porous polyethylene scaffolds are subjected to N(2) + H(2) plasma treatment, in the first step. Subsequently the sophorolipids are covalently attached to the amine groups on the polymer surface through simple amide chemistry to yield sophorolipid grafted polymer scaffolds. These are then exposed to Ag(+) ions under appropriate conditions leading to the formation of silver nanoparticles immobilized on the polymer scaffolds. It has been found that while bacteria do not survive on these silver studded scaffolds, CHO-K1 cells thrive on them making them good candidates for tissue engineering and bio-implant applications. PMID:21643585

  11. Three-dimensional porous scaffolds at the crossroads of tissue engineering and cell-based gene therapy.

    PubMed

    Coutu, Daniel L; Yousefi, Azizeh-Mitra; Galipeau, Jacques

    2009-10-15

    In the last 20 years, more than 1,500 gene therapy clinical trials have been approved worldwide targeting a variety of indications, from inherited monogenic diseases to acquired conditions such as cancer, cardiovascular and infectious diseases. However, concerns about the safety and efficacy of gene therapy pharmaceuticals justify the development of alternative strategies to ensure the clinical translation of this still promising field. In particular, ex vivo gene therapy strategies using autologous adult stem cells coupled to three-dimensional (3D) porous scaffolds show great promises in preclinical studies. Developments in the fields of biomaterial sciences and tissue engineering have already helped understanding how we can harness to regenerative potential of many cell types to create artificial tissues and organs and vastly improve the engraftment of ex vivo manipulated adult stem cells. In this article, we will review the current state of the art in tissue engineering by exploring the various types of clinically available biomaterials and the methods used to process them into complex 3D scaffolds. We will then review how these technologies are applied in cell-based gene therapy and identify novel avenues of research that may benefit patients in the near future.

  12. Optimization and Use of 3D sintered porous material in medical field for mixing fibrin glue.

    NASA Astrophysics Data System (ADS)

    Delmotte, Y.; Laroumanie, H.; Brossard, G.

    2012-04-01

    In medical field, Mixing of two or more chemical components (liquids and/or gases) is extremely important as improper mixing can affect the physico-chemical properties of the final product. At Baxter Healthcare Corporation, we are using a sintered porous material (PM) as a micro-mixer in medical device for mixing Fibrinogen and Thrombin in order to obtain a homogeneous polymerized Fibrin glue clot used in surgery. First trials were carried out with an interconnected PM from Porvair® (made of PE - porosity: 40% - permeability: 18Darcy). The injection rate is very low, usually about 10mL/min (Re number about 50) which keeps fluids in a laminar flow. Such a low flow rate does not favour mixing of fluids having gradient of viscosity if a mixer is not used. Promising results that were obtained lead the team to understand this ability to mix fluids which will be presented in the poster. Topology of porous media (PM) which associates a solid phase with interconnected (or not) porous structure is known and used in many commodity products. Researches on PM usually focus on flows inside this structure. By opposition to transport and filtration capacity, as well as mechanic and thermic properties, mixing is rarely associated with PM. However over the past few years, we shown that some type of PM have a real capacity to mix certain fluids. Poster will also describe the problematic of mixing complex biological fluids as fibrinogen and Thrombin. They indeed present a large viscosity difference (ratio about 120) limiting the diffusion and the interaction between the two solutions. As those products are expensive, we used Water (1cPo) and Glycerol 87% (120cPo) which are matching the viscosities of Thrombin and Fibrinogen. A parametric investigation of the "porous micro-mixer" as well as a scale up investigation was carried out to examine the influence of both diffusion and advection to successful mix fluids of different viscosity. Experiments were implemented with Planar Laser

  13. PHT3D-UZF: A reactive transport model for variably-saturated porous media

    USGS Publications Warehouse

    Wu, Ming Zhi; Post, Vincent E. A.; Salmon, S. Ursula; Morway, Eric; Prommer, H.

    2016-01-01

    A modified version of the MODFLOW/MT3DMS-based reactive transport model PHT3D was developed to extend current reactive transport capabilities to the variably-saturated component of the subsurface system and incorporate diffusive reactive transport of gaseous species. Referred to as PHT3D-UZF, this code incorporates flux terms calculated by MODFLOW's unsaturated-zone flow (UZF1) package. A volume-averaged approach similar to the method used in UZF-MT3DMS was adopted. The PHREEQC-based computation of chemical processes within PHT3D-UZF in combination with the analytical solution method of UZF1 allows for comprehensive reactive transport investigations (i.e., biogeochemical transformations) that jointly involve saturated and unsaturated zone processes. Intended for regional-scale applications, UZF1 simulates downward-only flux within the unsaturated zone. The model was tested by comparing simulation results with those of existing numerical models. The comparison was performed for several benchmark problems that cover a range of important hydrological and reactive transport processes. A 2D simulation scenario was defined to illustrate the geochemical evolution following dewatering in a sandy acid sulfate soil environment. Other potential applications include the simulation of biogeochemical processes in variably-saturated systems that track the transport and fate of agricultural pollutants, nutrients, natural and xenobiotic organic compounds and micropollutants such as pharmaceuticals, as well as the evolution of isotope patterns.

  14. PHT3D-UZF: A Reactive Transport Model for Variably-Saturated Porous Media.

    PubMed

    Wu, Ming Zhi; Post, Vincent E A; Salmon, S Ursula; Morway, Eric D; Prommer, Henning

    2016-01-01

    A modified version of the MODFLOW/MT3DMS-based reactive transport model PHT3D was developed to extend current reactive transport capabilities to the variably-saturated component of the subsurface system and incorporate diffusive reactive transport of gaseous species. Referred to as PHT3D-UZF, this code incorporates flux terms calculated by MODFLOW's unsaturated-zone flow (UZF1) package. A volume-averaged approach similar to the method used in UZF-MT3DMS was adopted. The PHREEQC-based computation of chemical processes within PHT3D-UZF in combination with the analytical solution method of UZF1 allows for comprehensive reactive transport investigations (i.e., biogeochemical transformations) that jointly involve saturated and unsaturated zone processes. Intended for regional-scale applications, UZF1 simulates downward-only flux within the unsaturated zone. The model was tested by comparing simulation results with those of existing numerical models. The comparison was performed for several benchmark problems that cover a range of important hydrological and reactive transport processes. A 2D simulation scenario was defined to illustrate the geochemical evolution following dewatering in a sandy acid sulfate soil environment. Other potential applications include the simulation of biogeochemical processes in variably-saturated systems that track the transport and fate of agricultural pollutants, nutrients, natural and xenobiotic organic compounds and micropollutants such as pharmaceuticals, as well as the evolution of isotope patterns. PMID:25628017

  15. Hierarchic micro-patterned porous scaffolds via electrochemical replica-deposition enhance neo-vascularization.

    PubMed

    Varoni, Elena Maria; Altomare, Lina; Cochis, Andrea; GhalayaniEsfahani, Arash; Cigada, Alberto; Rimondini, Lia; De Nardo, Luigi

    2016-04-21

    Neo-vascularization is a key factor in tissue regeneration within porous scaffolds. Here, we tested the hypothesis that micro-patterned scaffolds, with precisely-designed, open micro-channels, might help endothelial cells to produce intra-scaffold vascular networks. Three series of micro-patterned scaffolds were produced via electrochemical replica-deposition of chitosan and cross-linking. All had regularly-oriented micro-channels (ϕ 500 μm), which differed for the inter-channel spacing, at 600, 700, or 900 μm, respectively. Random-pore scaffolds, using the same technique, were taken as controls. Physical-mechanical characterization revealed high water uptake and favorable elastic mechanical behavior for all scaffolds, slightly reduced in the presence of cross-linking and enhanced with the 700 μm-spaced micro-pattern. At MTT assay, mouse endothelial cell viability was >90% at day 1, 3 and 7, confirmed by visual examination with scanning electron microscopy (SEM). Intra-scaffold cell density, at fluorescence analysis, was higher for the 600 μm-spaced and the 700 μm-spaced micro-patterns over the others. The 700 μm-spaced scaffold was selected for the in vivo testing, to be compared to the random-pore one. Neither type produced an inflammatory reaction; both showed excellent tissue ingrowth. Micro-patterned scaffolds enhanced neo-vascularization, demonstrated by immunofluorescent, semi-quantitative analyses. These findings support the use of micro-patterned porous scaffolds, with adequately spaced micro-channels, to promote neo-vascularization.

  16. Silver nanoparticle studded porous polyethylene scaffolds: bacteria struggle to grow on them while mammalian cells thrive

    NASA Astrophysics Data System (ADS)

    D'Britto, Virginia; Kapse, Harsha; Babrekar, Harshada; Prabhune, A. A.; Bhoraskar, S. V.; Premnath, V.; Prasad, B. L. V.

    2011-07-01

    Silver nanoparticle studded scaffolds were prepared by exploiting the Ag+ ion reducing activity of sophorolipids--a class of `glycolipids' that cap the ensuing nanoparticles as well. To achieve this, the porous polyethylene scaffolds are subjected to N2 + H2 plasma treatment, in the first step. Subsequently the sophorolipids are covalently attached to the amine groups on the polymer surface through simple amide chemistry to yield sophorolipid grafted polymer scaffolds. These are then exposed to Ag+ ions under appropriate conditions leading to the formation of silver nanoparticles immobilized on the polymer scaffolds. It has been found that while bacteria do not survive on these silver studded scaffolds, CHO-K1 cells thrive on them making them good candidates for tissue engineering and bio-implant applications.Silver nanoparticle studded scaffolds were prepared by exploiting the Ag+ ion reducing activity of sophorolipids--a class of `glycolipids' that cap the ensuing nanoparticles as well. To achieve this, the porous polyethylene scaffolds are subjected to N2 + H2 plasma treatment, in the first step. Subsequently the sophorolipids are covalently attached to the amine groups on the polymer surface through simple amide chemistry to yield sophorolipid grafted polymer scaffolds. These are then exposed to Ag+ ions under appropriate conditions leading to the formation of silver nanoparticles immobilized on the polymer scaffolds. It has been found that while bacteria do not survive on these silver studded scaffolds, CHO-K1 cells thrive on them making them good candidates for tissue engineering and bio-implant applications. Electronic supplementary information (ESI) available: See DOI: 10.1039/c1nr10152d

  17. A nickel hydroxide-coated 3D porous graphene hollow sphere framework as a high performance electrode material for supercapacitors.

    PubMed

    Zhang, Fengqiao; Zhu, Dong; Chen, Xi'an; Xu, Xin; Yang, Zhi; Zou, Chao; Yang, Keqin; Huang, Shaoming

    2014-03-01

    A three-dimensional (3D) porous graphene hollow sphere (PGHS) framework has been fabricated via a hard template method and used to anchor α-Ni(OH)2 nanoparticles with the size of about 4 nm through electrochemical deposition. It is found that a 3D PGHS framework can improve the capacitive performance of Ni(OH)2 effectively. In hybrid materials, α-Ni(OH)2 achieves the high specific capacitance of 2815 F g(-1) at a scan rate of 5 mV s(-1) and 1950 F g(-1) even at 200 mV s(-1) with a capacitance retention of about 70%, indicating that the α-Ni(OH)2-coated 3D PGHS framework exhibits high rate capability. The excellent performance of such hybrid material is believed to be due to the smaller size of Ni(OH)2 nanoparticles and the PGHS framework with large specific surface area promoting efficient electron transport and facilitating the electrolyte ions migration. These impressive results suggest that the composite is a promising electrode material for an efficient supercapacitor.

  18. Bone regeneration using a freeze-dried 3D gradient-structured scaffold incorporating OIC-A006-loaded PLGA microspheres based on β-TCP/PLGA.

    PubMed

    Lin, Liulan; Gao, Haitao; Dong, Yangyang

    2015-01-01

    To reveal the latent capacity of the growth factor-like low-molecular-weight material OIC-A006 in tissue regeneration, it is essential to design a porous scaffold in order to concurrently accommodate cells and drug release in a controlled manner. Consequently, we fabricated poly (L-lactide-co-glycolide) (PLGA)-based microspheres with an OIC-A006-loaded gradient-structured β-TCP/PLGA scaffold by freeze-drying which could then be used for drug delivery and bone regeneration. The OIC-A006-loaded β-TCP/PLGA scaffold consisted of two parts which loaded different doses of OIC-A006 (6.25 μM, outside; 12.5 μM, inside). The porosity, compressive strength, SEM, degradation, and cumulative amount of drug release in vitro were characterized. Furthermore, we confirmed the incorporation of OIC-A006 into the PLGA-based microspheres within the scaffolds using UV-spectrophotometry, and the amount of drug remaining in the scaffold was maintained by 10 % for up to 28 days. The drug release was slower in the normal-structured drug-loaded scaffold. The OIC-A006 released action from the OIC-A006-loaded β-TCP/PLGA scaffold with ideal therapeutic prospects in tissue regeneration. In vitro cell culture results showed that this gradient-structured composite scaffold can induce the adhesion and proliferation of rat bone marrow stromal cells towards osteoblasts. These results showed that the newly developed OIC-A006-loaded scaffolds with gradient structure can be potentially applied to bone regeneration in clinical applications. PMID:25577209

  19. Fabrication of alumina porous scaffolds with aligned oriented pores for bone tissue engineering applications

    NASA Astrophysics Data System (ADS)

    Sarhadi, Fatemeh; Shafiee Afarani, Mahdi; Mohebbi-Kalhori, Davod; Shayesteh, Masoud

    2016-04-01

    In the present study, porous alumina scaffolds with specific orientation and anisotropic properties are fabricated for application in bone tissue repair. The scaffolds with double shape pores, tubular oriented and isotropic rounded pores, were prepared using alumina and silica as starting materials by the slip casting route. Milled polyurethane foam and silk fibers were applied as replica materials as well. The effect of fiber types and diameter and number of fibers on the microstructure and pore size was studied. Moreover, different characteristics such as porosity, density, orientation, flexural strength and compressive strength of the samples were investigated. Results showed that various fibers with different diameters and numbers led to forming the pores with different pore sizes, microstructure and consequently changes in the physical and mechanical properties. In addition, the simultaneous presence of fibers and particles led to more porous scaffolds. The oriented tiny micro-tube and rounded pores were observed in all porous ceramic scaffolds. Mechanical testing showed an anisotropy in the mechanical behaviors such that higher strengths were observed in the oriented pore direction than that of transverse. With increasing the number and diameter of silk fibers, the scaffolds with a high porosity up to 68 vol% and proper flexural strength were obtained.

  20. A synergistic approach to the design, fabrication and evaluation of 3D printed micro and nano featured scaffolds for vascularized bone tissue repair

    NASA Astrophysics Data System (ADS)

    Holmes, Benjamin; Bulusu, Kartik; Plesniak, Michael; Zhang, Lijie Grace

    2016-02-01

    3D bioprinting has begun to show great promise in advancing the development of functional tissue/organ replacements. However, to realize the true potential of 3D bioprinted tissues for clinical use requires the fabrication of an interconnected and effective vascular network. Solving this challenge is critical, as human tissue relies on an adequate network of blood vessels to transport oxygen, nutrients, other chemicals, biological factors and waste, in and out of the tissue. Here, we have successfully designed and printed a series of novel 3D bone scaffolds with both bone formation supporting structures and highly interconnected 3D microvascular mimicking channels, for efficient and enhanced osteogenic bone regeneration as well as vascular cell growth. Using a chemical functionalization process, we have conjugated our samples with nano hydroxyapatite (nHA), for the creation of novel micro and nano featured devices for vascularized bone growth. We evaluated our scaffolds with mechanical testing, hydrodynamic measurements and in vitro human mesenchymal stem cell (hMSC) adhesion (4 h), proliferation (1, 3 and 5 d) and osteogenic differentiation (1, 2 and 3 weeks). These tests confirmed bone-like physical properties and vascular-like flow profiles, as well as demonstrated enhanced hMSC adhesion, proliferation and osteogenic differentiation. Additional in vitro experiments with human umbilical vein endothelial cells also demonstrated improved vascular cell growth, migration and organization on micro-nano featured scaffolds.

  1. A synergistic approach to the design, fabrication and evaluation of 3D printed micro and nano featured scaffolds for vascularized bone tissue repair

    PubMed Central

    Holmes, Benjamin; Bulusu, Kartik; Plesniak, Michael; Zhang, Lijie Grace

    2016-01-01

    3D bioprinting has begun to show great promise in advancing the development of functional tissue/organ replacements. However, to realize the true potential of 3D bioprinted tissues for clinical use requires the fabrication of an interconnected and effective vascular network. Solving this challenge is critical, as human tissue relies on an adequate network of blood vessels to transport oxygen, nutrients, other chemicals, biological factors and waste, in and out of the tissue. Here, we have successfully designed and printed a series of novel 3D bone scaffolds with both bone formation supporting structures and highly interconnected 3D microvascular mimicking channels, for efficient and enhanced osteogenic bone regeneration as well as vascular cell growth. Using a chemical functionalization process, we have conjugated our samples with nano hydroxyapatite (nHA), for the creation of novel micro and nano featured devices for vascularized bone growth. We evaluated our scaffolds with mechanical testing, hydrodynamic measurements and in vitro human mesenchymal stem cell (hMSC) adhesion (4 h), proliferation (1, 3 and 5 d) and osteogenic differentiation (1, 2 and 3 weeks). These tests confirmed bone-like physical properties and vascular-like flow profiles, as well as demonstrated enhanced hMSC adhesion, proliferation and osteogenic differentiation. Additional in vitro experiments with human umbilical vein endothelial cells also demonstrated improved vascular cell growth, migration and organization on micro-nano featured scaffolds. PMID:26758780

  2. A synergistic approach to the design, fabrication and evaluation of 3D printed micro and nano featured scaffolds for vascularized bone tissue repair.

    PubMed

    Holmes, Benjamin; Bulusu, Kartik; Plesniak, Michael; Zhang, Lijie Grace

    2016-02-12

    3D bioprinting has begun to show great promise in advancing the development of functional tissue/organ replacements. However, to realize the true potential of 3D bioprinted tissues for clinical use requires the fabrication of an interconnected and effective vascular network. Solving this challenge is critical, as human tissue relies on an adequate network of blood vessels to transport oxygen, nutrients, other chemicals, biological factors and waste, in and out of the tissue. Here, we have successfully designed and printed a series of novel 3D bone scaffolds with both bone formation supporting structures and highly interconnected 3D microvascular mimicking channels, for efficient and enhanced osteogenic bone regeneration as well as vascular cell growth. Using a chemical functionalization process, we have conjugated our samples with nano hydroxyapatite (nHA), for the creation of novel micro and nano featured devices for vascularized bone growth. We evaluated our scaffolds with mechanical testing, hydrodynamic measurements and in vitro human mesenchymal stem cell (hMSC) adhesion (4 h), proliferation (1, 3 and 5 d) and osteogenic differentiation (1, 2 and 3 weeks). These tests confirmed bone-like physical properties and vascular-like flow profiles, as well as demonstrated enhanced hMSC adhesion, proliferation and osteogenic differentiation. Additional in vitro experiments with human umbilical vein endothelial cells also demonstrated improved vascular cell growth, migration and organization on micro-nano featured scaffolds.

  3. Healing of critical-size segmental defects in rat femora using strong porous bioactive glass scaffolds.

    PubMed

    Bi, Lianxiang; Zobell, Brett; Liu, Xin; Rahaman, Mohamed N; Bonewald, Lynda F

    2014-09-01

    The repair of structural bone defects such as segmental defects in the long bones of the limbs is a challenging clinical problem. In this study, the capacity of silicate (13-93) and borate (13-93B3) bioactive glass scaffolds (porosity=47-50%) to heal critical-size segmental defects in rat femurs was evaluated and compared with autografts. Defects were implanted with 13-93 and 13-93B3 scaffolds with a grid-like microstructure (compressive strength=86 MPa and 40 MPa, respectively), 13-93B3 scaffolds with an oriented microstructure (compressive strength=32 MPa) and autografts using intramedullary fixation. Twelve weeks post-implantation, the defects were harvested and evaluated using histomorphometric analysis. The percentage of new bone in the defects implanted with the three groups of glass scaffolds (25-28%) and the total von Kossa-positive area (32-38%) were not significantly different from the autografts (new bone=38%; von Kossa-positive area=40%) (p>0.05). New blood vessel area in the defects implanted with the glass scaffolds (4-8%) and the autografts (5%) showed no significant difference among the four groups. New cartilage formed in the 13-93 grid-like scaffolds (18%) was significantly higher than in 13-93B3 grid-like scaffolds (8%) and in the autografts (8%) (p=0.02). The results indicate that these strong porous bioactive glass scaffolds are promising synthetic implants for structural bone repair.

  4. Porous ovalbumin scaffolds with tunable properties: a resource-efficient biodegradable material for tissue engineering applications.

    PubMed

    Luo, Baiwen; Choong, Cleo

    2015-01-01

    Natural materials are promising alternatives to synthetic materials used in tissue engineering applications as they have superior biocompatibility and promote better cell attachment and proliferation. Ovalbumin, a natural polymer found in avian egg white, is an example of a nature-derived material. Despite the availability and reported biocompatibility of ovalbumin, limited research has been carried out to investigate the efficacy of ovalbumin-based scaffolds for adipose tissue engineering applications. Hence, the current study was carried out to investigate the effect of different crosslinkers on ovalbumin scaffold properties as first step towards the development of ovalbumin-based scaffolds for adipose tissue engineering applications. In this study, highly porous three-dimensional scaffolds were fabricated by using three different crosslinkers: glutaraldehyde, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 1,4-butanediol diglycidyl ether. Results showed that the overall scaffold properties such as morphology, pore size and mechanical properties could be modulated based on the type and concentration of crosslinkers used during the fabrication process. Subsequently, the efficacy of the different scaffolds for supporting cell proliferation was investigated. In vitro degradation was also carried on for the best scaffold based on the mechanical and cellular results. Overall, this study is a demonstration of the viability of ovalbumin-based scaffolds as cell carriers for soft tissue engineering applications. PMID:25158688

  5. Biological evaluation of porous aliphatic polyurethane/hydroxyapatite composite scaffolds for bone tissue engineering.

    PubMed

    Yang, Wanxun; Both, Sanne K; Zuo, Yi; Birgani, Zeinab Tahmasebi; Habibovic, Pamela; Li, Yubao; Jansen, John A; Yang, Fang

    2015-07-01

    Biomaterial scaffolds meant to function as supporting structures to osteogenic cells play a pivotal role in bone tissue engineering. Recently, we synthesized an aliphatic polyurethane (PU) scaffold via a foaming method using non-toxic components. Through this procedure a uniform interconnected porous structure was created. Furthermore, hydroxyapatite (HA) particles were introduced into this process to increase the bioactivity of the PU matrix. To evaluate the biological performances of these PU-based scaffolds, their influence on in vitro cellular behavior and in vivo bone forming capacity of the engineered cell-scaffold constructs was investigated in this study. A simulated body fluid test demonstrated that the incorporation of 40 wt % HA particles significantly promoted the biomineralization ability of the PU scaffolds. Enhanced in vitro proliferation and osteogenic differentiation of the seeded mesenchymal stem cells were also observed on the PU/HA composite. Next, the cell-scaffold constructs were implanted subcutaneously in a nude mice model. After 8 weeks, a considerable amount of vascularized bone tissue with initial marrow stroma development was generated in both PU and PU/HA40 scaffold. In conclusion, the PU/HA composite is a potential scaffold for bone regeneration applications.

  6. Porous ovalbumin scaffolds with tunable properties: a resource-efficient biodegradable material for tissue engineering applications.

    PubMed

    Luo, Baiwen; Choong, Cleo

    2015-01-01

    Natural materials are promising alternatives to synthetic materials used in tissue engineering applications as they have superior biocompatibility and promote better cell attachment and proliferation. Ovalbumin, a natural polymer found in avian egg white, is an example of a nature-derived material. Despite the availability and reported biocompatibility of ovalbumin, limited research has been carried out to investigate the efficacy of ovalbumin-based scaffolds for adipose tissue engineering applications. Hence, the current study was carried out to investigate the effect of different crosslinkers on ovalbumin scaffold properties as first step towards the development of ovalbumin-based scaffolds for adipose tissue engineering applications. In this study, highly porous three-dimensional scaffolds were fabricated by using three different crosslinkers: glutaraldehyde, 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide and 1,4-butanediol diglycidyl ether. Results showed that the overall scaffold properties such as morphology, pore size and mechanical properties could be modulated based on the type and concentration of crosslinkers used during the fabrication process. Subsequently, the efficacy of the different scaffolds for supporting cell proliferation was investigated. In vitro degradation was also carried on for the best scaffold based on the mechanical and cellular results. Overall, this study is a demonstration of the viability of ovalbumin-based scaffolds as cell carriers for soft tissue engineering applications.

  7. [Study on the development of Ag-nano-hydroxyapatite/polyamide66 porous scaffolds with surface mineralization].

    PubMed

    Fan, Jianbo; Chang, Shan; Dong, Mina; Huang, Di; Li, Jidong; Jiang, Dianming

    2012-12-01

    Bacterial infection after implantation of bone tissue engineering scaffolds is still a serious clinical problem. Ag-nano-hydroxyapatite/polyamide66 (Ag-nHA/PA66) antibacterial composite scaffold were prepared with phase-inversion method in this study. The scaffolds were mineralized in saturated calcium phosphate solution at 37 degrees C for 1 day. The microstructure and the newly formed nano-apatite deposition on the scaffolds before and after mineralization were observed using scanning electron microscopy (SEM). In order to investigate the release behaviors of Ag+, the Ag-nHA/PA66 scaffolds were immersed into 5 ml PBS at 37 degrees C for a different period between 3 h and 168 h before and after mineralization. Then the samples were cultured with E. coli (8099) to test the antibacterial effect of the scaffolds. The results showed that, after mineralization, Ag-nHA/PA66 porous scaffolds still possessed a good inter-connection and a new apatite layer was formed on the surface of the scaffolds. The average macropore size was 626.61 +/- 141.94 microm, the porosity was 76.89 +/- 8.21% and the compressive strength was 2.94 +/- 1.12 MPa. All these physical parameters had no significant difference from those of the un-mineralized scaffolds. The Ag+ release of the scaffolds with and without mineralization was fast within 1 day and then kept slow and stable after 1 day. The antibacterial test confirmed that after mineralization the scaffolds had good antibacterial effects on E. coli. PMID:23469542

  8. Bilayer porous scaffold based on poly-(ɛ-caprolactone) nanofibrous membrane and gelatin sponge for favoring cell proliferation

    NASA Astrophysics Data System (ADS)

    Zhou, Zhihua; Zhou, Yang; Chen, Yiwang; Nie, Huarong; Wang, Yang; Li, Fan; Zheng, Yan

    2011-12-01

    Electrospun poly-(ɛ-caprolactone) (PCL) nanofibers has been widely used in the medical prosthesis. However, poor hydrophilicity and the lack of natural recognition sites for covalent cell-recognition signal molecules to promote cell attachment have limited its utility as tissue scaffolds. In this study, Bilayer porous scaffolds based on PCL electrospun membranes and gelatin (GE) sponges were fabricated through soft hydrolysis of PCL electrospun followed by grafting gelatin onto the fiber surface, through crosslinking and freeze drying treatment of additional gelatin coat and grafted gelatin surface. GE sponges were stably anchored on PCL membrane surface with the aid of grafted GE molecules. The morphologies of bilayer porous scaffolds were observed through SEM. The contact angle of the scaffolds was 0°, the mechanical properties of scaffolds were measured by tensile test, Young's moduli of PCL scaffolds before and after hydrolysis are 66-77.3 MPa and 62.3-75.4 MPa, respectively. Thus, the bilayer porous scaffolds showed excellent hydrophilic surface and desirable mechanical strength due to the soft hydrolysis and GE coat. The cell culture results showed that the adipose derived mesenchymal stem cells did more favor to adhere and grow on the bilayer porous scaffolds than on PCL electrospun membranes. The better cell affinity of the final bilayer scaffolds not only attributed to the surface chemistry but also the introduction of bilayer porous structure.

  9. Parametric Characterization of Porous 3D Bioscaffolds Fabricated by an Adaptive Foam Reticulation Technique

    NASA Astrophysics Data System (ADS)

    Winnett, James; Mallick, Kajal K.

    2014-04-01

    Commercially pure titanium (Ti) and its alloys, in particular, titanium-vanadium-aluminium (Ti-6Al-4V), have been used as biomaterials due to their mechanical similarities to bone, good biocompatibility, and inertness in vivo. The introduction of porosity to the scaffolds leads to optimized mechanical properties and enhanced biological activity. The adaptive foam reticulation (AFR) technique has been previously used to generate hydroxyapatite bioscaffolds with enhanced cell behavior due to the generation of macroporous structures with microporous struts that provided routes for cell infiltration as well as attachment sites. Sacrificial polyurethane templates of 45 ppi and 90 ppi were coated in biomaterial-based slurries containing either Ti or Ti-6Al-4V as the biomaterial and camphene as the porogen. The resultant macropore sizes of 100-550 μm corresponded well with the initial template pore sizes while camphene produced micropores of 1-10 μm, with the level of microporosity related to the amount of porogen inclusion.

  10. Nanoscale modification of porous gelatin scaffolds with chondroitin sulfate for corneal stromal tissue engineering.

    PubMed

    Lai, Jui-Yang; Li, Ya-Ting; Cho, Ching-Hsien; Yu, Ting-Chun

    2012-01-01

    Recent studies reflect the importance of using naturally occurring biopolymers as three-dimensional corneal keratocyte scaffolds and suggest that the porous structure of gelatin materials may play an important role in controlling nutrient uptake. In the current study, the authors further consider the application of carbodiimide cross-linked porous gelatin as an alternative to collagen for corneal stromal tissue engineering. The authors developed corneal keratocyte scaffolds by nanoscale modification of porous gelatin materials with chondroitin sulfate (CS) using carbodiimide chemistry. Scanning electron microscopy/energy dispersive X-ray spectroscopy and Fourier transform infrared spectroscopy showed that the amount of covalently incorporated polysaccharide was significantly increased when the CS concentration was increased from 0% to 1.25% (w/v). In addition, as demonstrated by dimethylmethylene blue assays, the CS content in these samples was in the range of 0.078-0.149 nmol per 10 mg scaffold. When compared with their counterparts without CS treatment, various CS-modified porous gelatin membranes exhibited higher levels of water content, light transmittance, and amount of permeated nutrients but possessed lower Young's modulus and resistance against protease digestion. The hydrophilic and mechanical properties of scaffolds modified with 0.25% CS were comparable with those of native corneas. The samples from this group were biocompatible with the rabbit corneal keratocytes and showed enhanced proliferative and biosynthetic capacity of cultured cells. In summary, the authors found that the nanoscale-level modification has influence on the characteristics and cell-material interactions of CS-containing gelatin hydrogels. Porous membranes with a CS content of 0.112 ± 0.003 nmol per 10 mg scaffold may hold potential for use in corneal stromal tissue engineering. PMID:22403490

  11. Enhanced human bone marrow mesenchymal stem cell functions in novel 3D cartilage scaffolds with hydrogen treated multi-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Holmes, Benjamin; Castro, Nathan J.; Li, Jian; Keidar, Michael; Zhang, Lijie Grace

    2013-09-01

    Cartilage tissue is a nanostructured tissue which is notoriously hard to regenerate due to its extremely poor inherent regenerative capacity and complex stratified architecture. Current treatment methods are highly invasive and may have many complications. Thus, the goal of this work is to use nanomaterials and nano/microfabrication methods to create novel biologically inspired tissue engineered cartilage scaffolds to facilitate human bone marrow mesenchymal stem cell (MSC) chondrogenesis. To this end we utilized electrospinning to design and fabricate a series of novel 3D biomimetic nanostructured scaffolds based on hydrogen (H2) treated multi-walled carbon nanotubes (MWCNTs) and biocompatible poly(L-lactic acid) (PLLA) polymers. Specifically, a series of electrospun fibrous PLLA scaffolds with controlled fiber dimension were fabricated in this study. In vitro MSC studies showed that stem cells prefer to attach in the scaffolds with smaller fiber diameter. More importantly, the MWCNT embedded scaffolds showed a drastic increase in mechanical strength and a compressive Young’s modulus matching to natural cartilage. Furthermore, our MSC differentiation results demonstrated that incorporation of the H2 treated carbon nanotubes and poly-L-lysine coating can induce more chondrogenic differentiations of MSCs than controls. After two weeks of culture, PLLA scaffolds with H2 treated MWCNTs and poly-L-lysine can achieve the highest glycosaminoglycan synthesis, making them promising for further exploration for cartilage regeneration.

  12. Enhanced human bone marrow mesenchymal stem cell functions in novel 3D cartilage scaffolds with hydrogen treated multi-walled carbon nanotubes.

    PubMed

    Holmes, Benjamin; Castro, Nathan J; Li, Jian; Keidar, Michael; Zhang, Lijie Grace

    2013-09-13

    Cartilage tissue is a nanostructured tissue which is notoriously hard to regenerate due to its extremely poor inherent regenerative capacity and complex stratified architecture. Current treatment methods are highly invasive and may have many complications. Thus, the goal of this work is to use nanomaterials and nano/microfabrication methods to create novel biologically inspired tissue engineered cartilage scaffolds to facilitate human bone marrow mesenchymal stem cell (MSC) chondrogenesis. To this end we utilized electrospinning to design and fabricate a series of novel 3D biomimetic nanostructured scaffolds based on hydrogen (H2) treated multi-walled carbon nanotubes (MWCNTs) and biocompatible poly(L-lactic acid) (PLLA) polymers. Specifically, a series of electrospun fibrous PLLA scaffolds with controlled fiber dimension were fabricated in this study. In vitro MSC studies showed that stem cells prefer to attach in the scaffolds with smaller fiber diameter. More importantly, the MWCNT embedded scaffolds showed a drastic increase in mechanical strength and a compressive Young's modulus matching to natural cartilage. Furthermore, our MSC differentiation results demonstrated that incorporation of the H2 treated carbon nanotubes and poly-L-lysine coating can induce more chondrogenic differentiations of MSCs than controls. After two weeks of culture, PLLA scaffolds with H2 treated MWCNTs and poly-L-lysine can achieve the highest glycosaminoglycan synthesis, making them promising for further exploration for cartilage regeneration.

  13. Physical and mechanical characterisation of 3D-printed porous titanium for biomedical applications.

    PubMed

    El-Hajje, Aouni; Kolos, Elizabeth C; Wang, Jun Kit; Maleksaeedi, Saeed; He, Zeming; Wiria, Florencia Edith; Choong, Cleo; Ruys, Andrew J

    2014-11-01

    The elastic modulus of metallic orthopaedic implants is typically 6-12 times greater than cortical bone, causing stress shielding: over time, bone atrophies through decreased mechanical strain, which can lead to fracture at the implantation site. Introducing pores into an implant will lower the modulus significantly. Three dimensional printing (3DP) is capable of producing parts with dual porosity features: micropores by process (residual pores from binder burnout) and macropores by design via a computer aided design model. Titanium was chosen due to its excellent biocompatibility, superior corrosion resistance, durability, osteointegration capability, relatively low elastic modulus, and high strength to weight ratio. The mechanical and physical properties of 3DP titanium were studied and compared to the properties of bone. The mechanical and physical properties were tailored by varying the binder (polyvinyl alcohol) content and the sintering temperature of the titanium samples. The fabricated titanium samples had a porosity of 32.2-53.4% and a compressive modulus of 0.86-2.48 GPa, within the range of cancellous bone modulus. Other physical and mechanical properties were investigated including fracture strength, density, fracture toughness, hardness and surface roughness. The correlation between the porous 3DP titanium-bulk modulus ratio and porosity was also quantified. PMID:25052736

  14. Physical and mechanical characterisation of 3D-printed porous titanium for biomedical applications.

    PubMed

    El-Hajje, Aouni; Kolos, Elizabeth C; Wang, Jun Kit; Maleksaeedi, Saeed; He, Zeming; Wiria, Florencia Edith; Choong, Cleo; Ruys, Andrew J

    2014-11-01

    The elastic modulus of metallic orthopaedic implants is typically 6-12 times greater than cortical bone, causing stress shielding: over time, bone atrophies through decreased mechanical strain, which can lead to fracture at the implantation site. Introducing pores into an implant will lower the modulus significantly. Three dimensional printing (3DP) is capable of producing parts with dual porosity features: micropores by process (residual pores from binder burnout) and macropores by design via a computer aided design model. Titanium was chosen due to its excellent biocompatibility, superior corrosion resistance, durability, osteointegration capability, relatively low elastic modulus, and high strength to weight ratio. The mechanical and physical properties of 3DP titanium were studied and compared to the properties of bone. The mechanical and physical properties were tailored by varying the binder (polyvinyl alcohol) content and the sintering temperature of the titanium samples. The fabricated titanium samples had a porosity of 32.2-53.4% and a compressive modulus of 0.86-2.48 GPa, within the range of cancellous bone modulus. Other physical and mechanical properties were investigated including fracture strength, density, fracture toughness, hardness and surface roughness. The correlation between the porous 3DP titanium-bulk modulus ratio and porosity was also quantified.

  15. Droplet fragmentation: 3D imaging of a previously unidentified pore-scale process during multiphase flow in porous media

    PubMed Central

    Pak, Tannaz; Butler, Ian B.; Geiger, Sebastian; van Dijke, Marinus I. J.; Sorbie, Ken S.

    2015-01-01

    Using X-ray computed microtomography, we have visualized and quantified the in situ structure of a trapped nonwetting phase (oil) in a highly heterogeneous carbonate rock after injecting a wetting phase (brine) at low and high capillary numbers. We imaged the process of capillary desaturation in 3D and demonstrated its impacts on the trapped nonwetting phase cluster size distribution. We have identified a previously unidentified pore-scale event during capillary desaturation. This pore-scale event, described as droplet fragmentation of the nonwetting phase, occurs in larger pores. It increases volumetric production of the nonwetting phase after capillary trapping and enlarges the fluid−fluid interface, which can enhance mass transfer between the phases. Droplet fragmentation therefore has implications for a range of multiphase flow processes in natural and engineered porous media with complex heterogeneous pore spaces. PMID:25646491

  16. Surface functionalization of Bioglass-derived porous scaffolds.

    PubMed

    Chen, Qi-Zhi; Rezwan, Kurosch; Françon, Virginie; Armitage, David; Nazhat, Showan N; Jones, Francis H; Boccaccini, Aldo R

    2007-07-01

    Like standard tissue culture plates, tissue engineering scaffolds can be chemically treated to couple proteins without losing the conformation and thus biological function of the proteins; a process called surface functionalization. In this work, the surface of novel 45S5 Bioglass-derived foam-like scaffolds, which exhibit adequate mechanical stability and tailorable bioresorbability, have been modified by applying 3-aminopropyl-triethoxysilane. The efficiency and stability of the surface modification were satisfactorily and quantitatively assessed by X-ray photoemission spectroscopy. It was also found that treatment in buffered (pH 8) water solution at 80 degrees C for 4h, applied during the surface functionalization procedure, accelerated the bioreactive kinetics of the scaffolds, i.e. the transition of the relatively bioinert but mechanically competent crystalline structure of the struts to a biodegradable but mechanically weak amorphous network during immersion in simulated body fluid. Thus the aqueous heat treatment is confirmed to be an important factor that must be considered in the design of these Bioglass-derived glass-ceramic scaffolds. Possible mechanisms responsible for the accelerated bioreactivity are proposed.

  17. Correlation between properties and microstructure of laser sintered porous β-tricalcium phosphate bone scaffolds

    NASA Astrophysics Data System (ADS)

    Shuai, Cijun; Feng, Pei; Zhang, Liyang; Gao, Chengde; Hu, Huanlong; Peng, Shuping; Min, Anjie

    2013-10-01

    A porous β-tricalcium phosphate (β-TCP) bioceramic scaffold was successfully prepared with our homemade selective laser sintering system. Microstructure observation by a scanning electron microscope showed that the grains grew from 0.21 to 1.32 μm with the decrease of laser scanning speed from 250 to 50 mm min-1. The mechanical properties increased mainly due to the improved apparent density when the laser scanning speed decreased to 150 mm min-1. When the scanning speed was further decreased, the grain size became larger and the mechanical properties severely decreased. The highest Vickers hardness and fracture toughness of the scaffold were 3.59 GPa and 1.16 MPa m1/2, respectively, when laser power was 11 W, spot size was 1 mm in diameter, layer thickness was 0.1-0.2 mm and laser scanning speed was 150 mm min-1. The biocompatibility of these scaffolds was assessed in vitro with MG63 osteoblast-like cells and human bone marrow mesenchymal stem cells. The results showed that all the prepared scaffolds are suitable for cell attachment and differentiation. Moreover, the smaller the grain size, the better the cell biocompatibility. The porous scaffold with a grain size of 0.71 μm was immersed in a simulated body fluid for different days to assess the bioactivity. The surface of the scaffold was covered by a bone-like apatite layer, which indicated that the β-TCP scaffold possesses good bioactivity. These discoveries demonstrated the evolution rule between grain microstructure and the properties that give a useful reference for the fabrication of β-TCP bone scaffolds.

  18. Porous magnesium/PLGA composite scaffolds for enhanced bone regeneration following tooth extraction.

    PubMed

    Brown, Andrew; Zaky, Samer; Ray, Herbert; Sfeir, Charles

    2015-01-01

    Sixty percent of implant-supported dental prostheses require bone grafting to enhance bone quantity and quality prior to implant placement. We have developed a metallic magnesium particle/PLGA composite scaffold to overcome the limitations of currently used dental bone grafting materials. This is the first report of porous metallic magnesium/PLGA scaffolds synthesized using a solvent casting, salt leaching method. We found that incorporation of varying amounts of magnesium into the PLGA scaffolds increased the compressive strength and modulus, as well as provided a porous structure suitable for cell infiltration, as measured by mercury intrusion porosimetry. Additionally, combining basic-degrading magnesium with acidic-degrading PLGA led to an overall pH buffering effect and long-term release of magnesium over the course of a 10-week degradation assay, as measured with inductively coupled plasma-atomic emission spectroscopy. Using an indirect proliferation assay adapted from ISO 10993:5, it was found that extracts of medium from degrading magnesium/PLGA scaffolds increased bone marrow stromal cell proliferation in vitro, a phenomenon observed by other groups investigating magnesium's impact on cells. Finally, magnesium/PLGA scaffold biocompatibility was assessed in a canine socket preservation model. Micro-computed tomography and histological analysis showed the magnesium/PLGA scaffolds to be safer and more effective at preserving bone height than empty controls. Three-dimensional magnesium/PLGA composite scaffolds show promise for dental socket preservation and also, potentially, orthopedic bone regeneration. These scaffolds could decrease inflammation observed with clinically used PLGA devices, as well as enhance osteogenesis, as observed with previously studied magnesium devices.

  19. Role of surfactant during microemulsion photopolymerization for the creation of three-dimensional (3D) liquid crystal elastomer microsphere spatial cell scaffolds

    NASA Astrophysics Data System (ADS)

    Hegmann, Elda; Bera, Tanmay; Malcuit, Christopher; Clements, Robert

    2016-06-01

    Three-dimensional (3D) cell scaffolds based on connected nematic liquid crystal elastomer microsphere architectures support the attachment and proliferation of C2C12 myoblasts, neuroblastomas (SHSY5Y) and human dermal fibroblasts (hDF). The microsphere spatial cell scaffolds were prepared by an oil-in-water microemulsion photopolymerization of reactive nematic mesogens in the presence of various surfactants, and the as-prepared scaffold constructs are composed of smooth surface microspheres with diameter ranging from 10 to 30 μm. We here investigate how the nature and type of surfactant used during the microemulsion photopolymerization impacts both the size and size distribution of the resulting microspheres as well as their surface morphology, i.e. the surface roughness.

  20. Enhancement of cell viability by fabrication of macroscopic 3D hydrogel scaffolds using an innovative cell-dispensing technique supplemented by preosteoblast-laden micro-beads.

    PubMed

    Lee, Hyeongjin; Ahn, Seunghyun; Chun, Wook; Kim, Geunhyung

    2014-04-15

    We propose a new cell-encapsulated dispensing method consisting of hydrogel struts, embedded with cell-laden micro-beads. To develop the scaffolds, we accommodated a three-axis robot dispensing system and aerosol spraying of a cross-linking agent to effect tentative surface gelation of hydrogel alginate struts. To show the feasibility of the method, we used pre-osteoblast (MC3T3-E1) cells. Using this technique, we obtained a reasonable cell viability (>90% after several culture periods) relative to that of a scaffold onto which cells were dispensed in the conventional manner, and successfully fabricated a realistic macroscopic pore-size in a controlled manner with 100% pore-interconnected 3D alginate hydrogel scaffolds of 20 mm × 20 mm × 6 mm.

  1. Biodegradable CSMA/PECA/Graphene Porous Hybrid Scaffold for Cartilage Tissue Engineering.

    PubMed

    Liao, JinFeng; Qu, Ying; Chu, BingYang; Zhang, XiaoNing; Qian, ZhiYong

    2015-01-01

    Owing to the limited repair capacity of articular cartilage, it is essential to develop tissue-engineered cartilage for patients suffering from joint disease and trauma. Herein, we prepared a novel hybrid scaffold composed of methacrylated chondroitin sulfate (CSMA), poly(ethylene glycol) methyl ether-ε-caprolactone-acryloyl chloride (MPEG-PCL-AC, PECA was used as abbreviation for MPEG-PCL-AC) and graphene oxide (GO) and evaluated its potential application in cartilage tissue engineering. To mimic the natural extracellular matrix (ECM) of cartilage, the scaffold had an adequate pore size, porosity, swelling ability, compression modulus and conductivity. Cartilage cells contacted with the scaffold remained viable and showed growth potential. Furthermore, CSMA/PECA/GO scaffold was biocompatible and had a favorable degradation rate. In the cartilage tissue repair of rabbit, Micro-CT and histology observation showed the group of CSMA/PECA/GO scaffold with cellular supplementation had better chondrocyte morphology, integration, continuous subchondral bone, and much thicker newly formed cartilage compared with scaffold group and control group. Our results show that the CSMA/PECA/GO hybrid porous scaffold can be applied in articular cartilage tissue engineering and may have great potential to in other types of tissue engineering applications. PMID:25961959

  2. Microwave-assisted synthesis of porous chitosan-modified montmorillonite-hydroxyapatite composite scaffolds.

    PubMed

    Kar, Sumanta; Kaur, Tejinder; Thirugnanam, A

    2016-01-01

    In this study, a porous chitosan-organically modified montmorillonite-hydroxyapatite (CS-OM-HA) composite scaffold was developed by combining microwave irradiation and gas foaming method. Hydroxyapatite (HA) particles of size ∼ 65 nm were synthesized and characterized by X-ray diffraction (XRD) and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy. The prepared composite scaffolds were characterized using ATR-FTIR, XRD, mercury intrusion porosimeter (MIP) and scanning electron microscopy (SEM) studies. The synergistic effect of HA and OM on the mechanical and in vitro biological properties (swelling, degradation, protein adsorption and bioactivity) of the composite scaffolds were evaluated. Swelling, degradation, mechanical property, bioactivity and protein adsorption studies of CS-OM-HA composite scaffolds have shown desirable results in comparison with the pure CS and CS-OM composite scaffolds. CS-OM-HA composite scaffolds were also found to be non-cytotoxic to MG 63 osteoblast cell lines. From the study, it can be concluded that the novel CS-OM-HA composite scaffold with improved mechanical and in vitro biological properties has wide potential in non-load bearing bone tissue engineering applications.

  3. Open-Porous Hydroxyapatite Scaffolds for Three-Dimensional Culture of Human Adult Liver Cells

    PubMed Central

    Schmelzer, Eva; Over, Patrick; Nettleship, Ian; Gerlach, Joerg C.

    2016-01-01

    Liver cell culture within three-dimensional structures provides an improved culture system for various applications in basic research, pharmacological screening, and implantable or extracorporeal liver support. Biodegradable calcium-based scaffolds in such systems could enhance liver cell functionality by providing endothelial and hepatic cell support through locally elevated calcium levels, increased surface area for cell attachment, and allowing three-dimensional tissue restructuring. Open-porous hydroxyapatite scaffolds were fabricated and seeded with primary adult human liver cells, which were embedded within or without gels of extracellular matrix protein collagen-1 or hyaluronan. Metabolic functions were assessed after 5, 15, and 28 days. Longer-term cultures exhibited highest cell numbers and liver specific gene expression when cultured on hydroxyapatite scaffolds in collagen-1. Endothelial gene expression was induced in cells cultured on scaffolds without extracellular matrix proteins. Hydroxyapatite induced gene expression for cytokeratin-19 when cells were cultured in collagen-1 gel while culture in hyaluronan increased cytokeratin-19 gene expression independent of the use of scaffold in long-term culture. The implementation of hydroxyapatite composites with extracellular matrices affected liver cell cultures and cell differentiation depending on the type of matrix protein and the presence of a scaffold. The hydroxyapatite scaffolds enable scale-up of hepatic three-dimensional culture models for regenerative medicine applications. PMID:27403430

  4. Biodegradable CSMA/PECA/Graphene Porous Hybrid Scaffold for Cartilage Tissue Engineering

    PubMed Central

    Liao, JinFeng; Qu, Ying; Chu, BingYang; Zhang, XiaoNing; Qian, ZhiYong

    2015-01-01

    Owing to the limited repair capacity of articular cartilage, it is essential to develop tissue-engineered cartilage for patients suffering from joint disease and trauma. Herein, we prepared a novel hybrid scaffold composed of methacrylated chondroitin sulfate (CSMA), poly(ethylene glycol) methyl ether-ε-caprolactone-acryloyl chloride (MPEG-PCL-AC, PECA was used as abbreviation for MPEG-PCL-AC) and graphene oxide (GO) and evaluated its potential application in cartilage tissue engineering. To mimic the natural extracellular matrix (ECM) of cartilage, the scaffold had an adequate pore size, porosity, swelling ability, compression modulus and conductivity. Cartilage cells contacted with the scaffold remained viable and showed growth potential. Furthermore, CSMA/PECA/GO scaffold was biocompatible and had a favorable degradation rate. In the cartilage tissue repair of rabbit, Micro-CT and histology observation showed the group of CSMA/PECA/GO scaffold with cellular supplementation had better chondrocyte morphology, integration, continuous subchondral bone, and much thicker newly formed cartilage compared with scaffold group and control group. Our results show that the CSMA/PECA/GO hybrid porous scaffold can be applied in articular cartilage tissue engineering and may have great potential to in other types of tissue engineering applications. PMID:25961959

  5. Open-Porous Hydroxyapatite Scaffolds for Three-Dimensional Culture of Human Adult Liver Cells.

    PubMed

    Finoli, Anthony; Schmelzer, Eva; Over, Patrick; Nettleship, Ian; Gerlach, Joerg C

    2016-01-01

    Liver cell culture within three-dimensional structures provides an improved culture system for various applications in basic research, pharmacological screening, and implantable or extracorporeal liver support. Biodegradable calcium-based scaffolds in such systems could enhance liver cell functionality by providing endothelial and hepatic cell support through locally elevated calcium levels, increased surface area for cell attachment, and allowing three-dimensional tissue restructuring. Open-porous hydroxyapatite scaffolds were fabricated and seeded with primary adult human liver cells, which were embedded within or without gels of extracellular matrix protein collagen-1 or hyaluronan. Metabolic functions were assessed after 5, 15, and 28 days. Longer-term cultures exhibited highest cell numbers and liver specific gene expression when cultured on hydroxyapatite scaffolds in collagen-1. Endothelial gene expression was induced in cells cultured on scaffolds without extracellular matrix proteins. Hydroxyapatite induced gene expression for cytokeratin-19 when cells were cultured in collagen-1 gel while culture in hyaluronan increased cytokeratin-19 gene expression independent of the use of scaffold in long-term culture. The implementation of hydroxyapatite composites with extracellular matrices affected liver cell cultures and cell differentiation depending on the type of matrix protein and the presence of a scaffold. The hydroxyapatite scaffolds enable scale-up of hepatic three-dimensional culture models for regenerative medicine applications.

  6. Colloid Transport in Unsaturated Porous Media: 3D Visualization Using Synchrotron X-Ray Microtomography

    NASA Astrophysics Data System (ADS)

    Brueck, C. L.; Meisenheimer, D.; Wildenschild, D.

    2015-12-01

    Understanding the mechanisms controlling colloid transport and deposition in the vadose zone is an important step in protecting our water resources. Not only may these particles themselves be undesirable contaminants, but they can also aid in the transport of smaller, molecular-scale contaminants by chemical attachment. In this research, we examined the influence that air-water interfaces (AWI) and air-water-solid contact lines (AWS) have on colloid deposition and mobilization in three-dimensional systems. We used x-ray microtomography to visualize the transport of hydrophobic colloids as they move through a partially saturated glass bead pack. Drainage and imbibition experiments were conducted using syringe pumps to control the flow of a colloid suspension through the porous media at 0.6 mL/hr. The high ionic strength fluid was adjusted to a pH of 9.5 and a concentration of 1.0 mol/L KI. During the drainage and imbibition, the flow was periodically halted and allowed to equilibrate before collecting the microtomography scans. Dopants were used to enhance the contrast between the four phases (water, air, beads, and colloids), including potassium iodide dissolved in the fluid, and an outer layer of silver coating the colloids. We hypothesized that AWIs and AWSs will scour and mobilize a significant percentage of colloids, and therefore reduce the concentration of colloids along the vertical profile of the column. The concentration of potassium iodide, and thus the ionic strength, necessary for adequate image segmentation was also explored in separate experiments so that the influence of ionic strength on colloid deposition and mobilization can be studied.

  7. Bacterial inhibition potential of 3D rapid-prototyped magnesium-based porous composite scaffolds–an in vitro efficacy study

    PubMed Central

    Ma, Rui; Lai, Yu-xiao; Li, Long; Tan, Hong-lue; Wang, Jia-li; Li, Ye; Tang, Ting-ting; Qin, Ling

    2015-01-01

    Bone infections are common in trauma-induced open fractures with bone defects. Therefore, developing anti-infection scaffolds for repairing bone defects is desirable. This study develoepd novel Mg-based porous composite scaffolds with a basal matrix composed of poly(lactic-co-glycolicacid) (PLGA) and tricalcium phosphate (TCP). A unique low-temperature rapid prototyping technology was used to fabricate the scaffolds, including PLGA/TCP (PT), PLGA/TCP/5%Mg (PT5M), PLGA/TCP/10%Mg (PT10M), and PLGA/TCP/15%Mg (PT15M). The bacterial adhesion and biofilm formation of Staphylococcus aureus were evaluated. The results indicated that the Mg-based scaffolds significantly inhibited bacterial adhesion and biofilm formation compared to PT, and the PT10M and PT15M exhibited significantly stronger anti-biofilm ability than PT5M. In vitro degratation tests revealed that the degradation of the Mg-based scaffolds caused an increase of pH, Mg2+ concentration and osmolality, and the increased pH may be one of the major contributing factors to the antibacterial function of the Mg-based scaffolds. Additionally, the PT15M exhibited an inhibitory effect on cell adhesion and proliferation of MC3T3-E1 cells. In conclusion, the PLGA/TCP/Mg scaffolds could inhibit bacterial adhesion and biofilm formation, and the PT10M scaffold was considered to be an effective composition with considerable antibacterial ability and good cytocompatibility. PMID:26346217

  8. A multistep procedure to prepare pre-vascularized cardiac tissue constructs using adult stem sells, dynamic cell cultures, and porous scaffolds

    PubMed Central

    Pagliari, Stefania; Tirella, Annalisa; Ahluwalia, Arti; Duim, Sjoerd; Goumans, Marie-Josè; Aoyagi, Takao; Forte, Giancarlo

    2014-01-01

    The vascularization of tissue engineered products represents a key issue in regenerative medicine which needs to be addressed before the translation of these protocols to the bedside can be foreseen. Here we propose a multistep procedure to prepare pre-vascularized three-dimensional (3D) cardiac bio-substitutes using dynamic cell cultures and highly porous biocompatible gelatin scaffolds. The strategy adopted exploits the peculiar differentiation potential of two distinct subsets of adult stem cells to obtain human vascularized 3D cardiac tissues. In the first step of the procedure, human mesenchymal stem cells (hMSCs) are seeded onto gelatin scaffolds to provide interconnected vessel-like structures, while human cardiomyocyte progenitor cells (hCMPCs) are stimulated in vitro to obtain their commitment toward the cardiac phenotype. The use of a modular bioreactor allows the perfusion of the whole scaffold, providing superior performance in terms of cardiac tissue maturation and cell survival. Both the cell culture on natural-derived polymers and the continuous medium perfusion of the scaffold led to the formation of a densely packaged proto-tissue composed of vascular-like and cardiac-like cells, which might complete maturation process and interconnect with native tissue upon in vivo implantation. In conclusion, the data obtained through the approach here proposed highlight the importance to provide stem cells with complementary signals in vitro able to resemble the complexity of cardiac microenvironment. PMID:24917827

  9. From Rice Bran to High Energy Density Supercapacitors: A New Route to Control Porous Structure of 3D Carbon

    PubMed Central

    Hou, Jianhua; Cao, Chuanbao; Ma, Xilan; Idrees, Faryal; Xu, Bin; Hao, Xin; Lin, Wei

    2014-01-01

    Controlled micro/mesopores interconnected structures of three-dimensional (3D) carbon with high specific surface areas (SSA) are successfully prepared by carbonization and activation of biomass (raw rice brans) through KOH. The highest SSA of 2475 m2 g−1 with optimized pore volume of 1.21 cm3 g−1 (40% for mesopores) is achieved for KOH/RBC = 4 mass ratio, than others. The as-prepared 3D porous carbon-based electrode materials for supercapacitors exhibit high specific capacitance specifically at large current densities of 10 A g−1 and 100 A g−1 i.e., 265 F g−1 and 182 F g−1 in 6 M KOH electrolyte, respectively. Moreover, a high power density ca. 1223 W kg−1 (550 W L−1) and energy density 70 W h kg−1 (32 W h L−1) are achieved on the base of active material loading (~10 mg cm2) in the ionic liquid. The findings can open a new avenue to use abundant agricultural by-products as ideal materials with promising applications in high-performance energy-storage devices. PMID:25434348

  10. Fabrication and characterization of interconnected porous biodegradable poly(ε-caprolactone) load bearing scaffolds.

    PubMed

    Allaf, Rula M; Rivero, Iris V

    2011-08-01

    In this study, poly(ε-caprolactone) (PCL)/poly(ethylene oxide) (PEO) (50:50 wt%) immiscible blend was used as a model system to investigate the feasibility of a novel solventless fabrication approach that combines cryomilling, compression molding and porogen leaching tech