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《仿生工程学报（英文版）》2014,11(4)
Biomimetic collagen/hydroxyapatite scaffolds have been prepared by microwave assisted co-titration of phosphorous acid-containing collagen solution and calcium hydroxide-containing solution. The resultant scaffolds have been characterised with respect to their mechanical properties, composition and microstructures. It was observed that the in situ precipitation process could combine collagen fibril formation and hydroxyapatite (HAp) formation in one process step. Collagen fibrils guided hydroxyapatite precipitation to form bone-mimic collagen/hydroxyapatite composite containing both intrafibrillar and interfibrillar hydroxyapatites. The mineral phase was determined as low crystalline calcium-deficient hydroxyapatite with calcium to phosphorus ratio (Ca/P) of 1.4. The obtained 1% (collagen/HAp = 75/25) scaffold has a porosity of 72% and a mean pore size of 69.4 µm. The incorporation of hydroxyapatite into collagen matrix improved the mechanical modulus of the scaffold significantly. This could be attributed to hydroxyapatite crystallites in collagen fibrils which restricted the deformation of the collagen fibril network, and the load transfer of the collagen to the higher modulus mineral component of the composite. 相似文献
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Farnaz Ghorbani Behafarid Ghalandari Ab Lateef Khan Dejian Li Ali Zamanian Baoqing Yu 《Biotechnology progress》2020,36(6):e3043
Electrospinning is a versatile technology for the fabrication of nanofibrous matrixes to regenerate defects. This study aims to develop a functionalized and electroconductive polymeric matrix to improve rat bone marrow mesenchymal stem cell adhesion, proliferation, and differentiation. Herein, the influence of the chemical composition of the substrate on homogeneous modification of the surface with mussel-inspired polydopamine (PDA) is focused. Accordingly, the deposition of PDA on the surface was proved by Fourier transform infrared spectroscopy. Morphologies of the scaffolds demonstrated homogeneous decoration of the polyvinyl alcohol (PVA)/polyurethane (PU)-polyaniline (PANI) matrixes with PDA, while a lower density of mussel-inspired polymer was observed in bare PU-PANI constructs. Although uniform and dense precipitation of PDA reduced conductivity of scaffolds 1.2 times compared with the samples with a low density of the PDA, 1.1 and 1.2 times enhancement in tensile strength and Young's modulus, respectively, were the strength of the applied process, especially in bone tissue engineering area. Contact angle measurements demonstrated about two times reduction in measured values, which shows improvement in hydrophilicity of PDA-modified PVA/PU-PANI fibers compared with PDA-coated PU-PANI ones. Swelling ratio and mass loss ratio calculations revealed enhancement in measured values as a function of homogeneous and dense coating, which arise from hydrophilicity of the polymeric substrate. The bioactivity test indicated that a dense layer of PDA strongly supports formations of hydroxyapatite-like crystals. Moreover, homogeneous decoration of conductive matrixes with PDA showed suitable cell viability, adhesion, and spreading while cell-scaffolds interactions improved under electrical stimulation. Higher expression of alkaline phosphatase and secretion of Collagen I under the electrical field proved the applicability of modified electroconductive scaffolds for further preclinical and clinical studies to introduce as a reconstructive bone substitute. 相似文献
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Biomimetic collagen/hydroxyapatite scaffolds have been prepared by microwave assisted co-titration of phosphorous acid-containing collagen solution and calcium hydroxide-containing solution. The resultant scaffolds have been characterised with respect to their mechanical properties, composition and microstructures. It was observed that the in situ precipitation process could combine collagen fibril formation and hydroxyapatite （HAp） formation in one process step. Collagen fibrils guided hydroxyapatite precipitation to form bone-mimic collagen/hydroxyapatite composite containing both intrafibrillar and interfibrillar hydroxyapatites. The mineral phase was determined as low crystalline calcium-deficient hydroxyapatite with calcium to phosphorus ratio （Ca/P） of 1.4. The obtained 1% （collagen/HAp = 75/25） scaffold has a porosity of 72% and a mean pore size of 69.4 ~tm. The incorporation of hydroxyapatite into collagen matrix improved the mechanical modulus of the scaffold significantly. This could be attributed to hydroxyapatite crystallites in collagen fibrils which restricted the deformation of the collagen fibril network, and the load transfer of the collagen to the higher modulus mineral component of the composite. 相似文献
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A. Rahbari H. Montazerian E. Davoodi S. Homayoonfar 《Computer methods in biomechanics and biomedical engineering》2017,20(3):231-241
The main aim of this research is to numerically obtain the permeability coefficient in the cylindrical scaffolds. For this purpose, a mathematical analysis was performed to derive an equation for desired porosity in terms of morphological parameters. Then, the considered cylindrical geometries were modeled and the permeability coefficient was calculated according to the velocity and pressure drop values based on the Darcy’s law. In order to validate the accuracy of the present numerical solution, the obtained permeability coefficient was compared with the published experimental data. It was observed that this model can predict permeability with the utmost accuracy. Then, the effect of geometrical parameters including porosity, scaffold pore structure, unit cell size, and length of the scaffolds as well as entrance mass flow rate on the permeability of porous structures was studied. Furthermore, a parametric study with scaling laws analysis of sample length and mass flow rate effects on the permeability showed good fit to the obtained data. It can be concluded that the sensitivity of permeability is more noticeable at higher porosities. The present approach can be used to characterize and optimize the scaffold microstructure due to the necessity of cell growth and transferring considerations. 相似文献
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Treatment of esophageal cancer often requires surgical procedures that involve removal. The current approaches to restore esophageal continuity however, are known to have limitations which may not result in full functional recovery. In theory, using a tissue engineered esophagus developed from the patient's own cells to replace the removed esophageal segment can be the ideal method of reconstruction. One of the key elements involved in the tissue engineering process is the scaffold which acts as a template for organization of cells and tissue development. While a number of scaffolds range from traditional non-biodegradable tubing to bioactive decellularized matrix have been proposed to engineer the esophagus in the past decade, results are still not yet favorable with many challenges relating to tissue quality need to be met improvements. The success of new esophageal tissue formation will ultimately depend on the success of the scaffold being able to meet the essential requirements specific to the esophageal tissue. Here, the design of the scaffold and its fabrication approaches are reviewed. In this paper, we review the current state of development in bioengineering the esophagus with particular emphasis on scaffold design. 相似文献
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Young‐Joon Seol Dong Yong Park Ju Young Park Sung Won Kim Seong Jin Park Dong‐Woo Cho 《Biotechnology and bioengineering》2013,110(5):1444-1455
Fabrication of three‐dimensional (3D) scaffolds with appropriate mechanical properties and desired architecture for promoting cell growth and new tissue formation is one of the most important efforts in tissue engineering field. Scaffolds fabricated from bioactive ceramic materials such as hydroxyapatite and tricalcium phosphate show promise because of their biological ability to support bone tissue regeneration. However, the use of ceramics as scaffold materials is limited because of their inherent brittleness and difficult processability. The aim of this study was to create robust ceramic scaffolds, which have a desired architecture. Such scaffolds were successfully fabricated by projection‐based microstereolithography, and dilatometric analysis was conducted to study the sintering behavior of the ceramic materials. The mechanical properties of the scaffolds were improved by infiltrating them with a polycaprolactone solution. The toughness and compressive strength of these ceramic/polymer scaffolds were about twice those of ceramic scaffolds. Furthermore, the osteogenic gene expression on ceramic/polymer scaffolds was better than that on ceramic scaffolds. Through this study, we overcame the limitations of previous research on fabricating ceramic scaffolds and these new robust ceramic scaffolds may provide a much improved 3D substrate for bone tissue regeneration. Biotechnol. Bioeng. 2013; 110: 1444–1455. © 2012 Wiley Periodicals, Inc. 相似文献
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Junxi Xiang Xinglong Zheng Peng Liu Lifei Yang Dinghui Dong Wanquan Wu 《Organogenesis》2016,12(3):128-142
Background and Aims: Decellularized liver matrix (DLM) hold great potential for reconstructing functional hepatic-like tissue (HLT) based on reseeding of hepatocytes or stem cells, but the shortage of liver donors is still an obstacle for potential application. Therefore, an appropriate alternative scaffold is needed to expand the donor pool. In this study, we explored the effectiveness of decellularized spleen matrix (DSM) for culturing of bone marrow mesenchymal stem cells (BMSCs), and promoting differentiation into hepatic-like cells.
Methods: Rats' spleen were harvested for DSM preparation by freezing/thawing and perfusion procedure. Then the mesenchymal stem cells derived from rat bone marrow were reseeded into DSM for dynamic culture and hepatic differentiation by a defined induction protocol.
Results: The research found that DSM preserved a 3-dimensional porous architecture, with native extracellular matrix and vascular network which was similar to DLM. The reseeded BMSCs in DSM differentiated into functional hepatocyte-like cells, evidenced by cytomorphology change, expression of hepatic-associated genes and protein markers, glycogen storage, and indocyanine green uptake. The albumin production (2.74±0.42 vs. 2.07±0.28 pg/cell/day) and urea concentration (75.92±15.64 vs. 52.07±11.46 pg/cell/day) in DSM group were remarkably higher than tissue culture flasks (TCF) group over the same differentiation period, P< 0.05.
Conclusion: This present study demonstrated that DSM might have considerable potential in fabricating hepatic-like tissue, particularly because it can facilitate hepatic differentiation of BMSCs which exhibited higher level and more stable functions. 相似文献
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Mass transfer limitations of scaffolds are currently hindering the development of 3-dimensional, clinically viable, tissue engineered constructs. We have developed a poly(lactide-co-glycolide) (PLGA) hollow fibre membrane scaffold that will provide support for cell culture, allow psuedovascularisation in vitro and provide channels for angiogenesis in vivo. We produced P(DL)LGA flat sheet membranes using 1, 4-dioxane and 1-methyl-2-pyrrolidinone (NMP) as solvents and water as the nonsolvent, and hollow fibre membranes, using NMP and water, by dry/wet- and wet-spinning. The resulting fibres had an outer diameter of 700 micro m and an inner diameter of 250 micro m with 0.2-1.0 micro m pores on the culture surface. It was shown that varying the air gap and temperature when spinning changed the morphology of the fibres. The introduction of a 50 mm air gap caused a dense skin of 5 micro m thick to form, compared to a skin of 0.5 micro m thick without an air gap. Spinning at 40 degrees C produced fibres with a more open central section in the wall that contained more, larger macrovoids compared to fibres spun at 20 degrees C. Culture of the immortalised osteogenic cell line 560pZIPv.neo (pZIP) was carried out on the P(DL)LGA flat sheets in static culture and in a P(DL)LGA hollow fibre bioreactor under counter-current flow conditions. Attachment and proliferation was statistically similar to tissue culture polystyrene on the flat sheets and was also successful in the hollow fibre bioreactor. The P(DL)LGA hollow fibres are a promising scaffold to address the size limitations currently seen in tissue engineered constructs. 相似文献
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Providing a scaffold that can supply nutrients on a large scale (several cubic centimeters) is the key to successfully regenerating vascularized tissue: biodegradable membranes are a promising new scaffold suited to this purpose. Poly(lactic-co-glycolic-acid) (PLGA) flat sheet membranes of different lactide:glycolide ratios, prepared by phase inversion using 1-methyl-2-pyrrolidinone (NMP) as the solvent and water as the nonsolvent, were compared by assessing attachment, proliferation and osteogenic function of human bone derived cells (HBDC). Three different lactide:glycolide ratios, 50:50, 75:25, and 100:0, were compared to tissue culture polystyrene (TCPS). For attachment, 50:50 and 75:25 had similar numbers to TCPS but 100:0 had significantly fewer cells than TCPS. 50:50 and 75:25 had significantly lower HBDC numbers after 7 days but 100:0 had similar numbers compared to TCPS. For proliferation the cell number on the membranes were similar to each other. After 3 weeks, osteoblastic function of the HBDC, shown by mineralization and alkaline phosphatase activity, was present but was significantly lower compared to the TCPS control but similar when the membranes were compared. PLGA membranes fabricated from a range of ratios support HBDC culture so the optimum scaffold composition can be selected based on other factors, such as degradation rate. 相似文献
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骨组织工程通过联合利用种子细胞、生物活性因子和支架材料等要素来构建骨组织再生微环境,从而促进骨缺损的修复重建来诱导骨再生。明胶微球具有多孔性、生物降解性、生物相容性及生物安全性等优势,是一种极具应用潜能的骨修复材料。明胶微球用于体外培养种子细胞时可实现高效扩增。多官能团结构使其可作为促血管再生因子、促骨再生因子及抗感染因子等多种药物的递送载体,缓释药物的同时也可实现微球的多功能化。在构建明胶微球支架时与其他生物材料复合及血管化性能的赋予可提高支架材料的综合性能,但目前支架的设计还存在如何兼顾材料多孔结构和力学性能的问题。本文主要综述了明胶微球的常见制备技术及其近年来在骨组织工程中的应用,并对未来的发展前景进行展望。
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《Cell Adhesion & Migration》2013,7(2):165-173
Mechanical stress plays a pivotal role in developing and maintaining tissues functionalities. Cells are constantly subjected to strain and compressive forces that are sensed by specialized membrane mechanosensors and converted in biochemical signals able to differently influence cellular behavior in terms of surviving, differentiation and extracellular matrix remodeling. This review focuses on the effects of mechanical strain on soft and hard tissues. Unexpectedly, different cells share almost the same membrane mechanosensors and the relative intracellular pathways, but to ultimately obtain very different biological effects. The events occurring in cardiovascular and bone tissues are treated in details, showing that integrins, cadherins, growth factor receptors and ions channels specifically expressed in the different tissues are the major actors of the sight. However, MAPkinases and RhoGTPases are mainly involved in the biochemical intracellular signaling directed to nuclear modifications. 相似文献