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BACKGROUND:Previous studies have shown that composite scaffold of chitosan and poly-L-lactic acid has good biocompatibility with some cells. OBJECTIVE:To study the biocompatibility of poly-L-lactic acid reinforced by chitosan and olfactory ensheathing cells. METHODS:In experimental group, olfactory ensheathing cells from Sprague-Dawley rats aged 1-3 days were incubated onto chitosan-reinforced poly-L-lactic acid film. And in control group, olfactory ensheathing cells were co-cultured with poly-L-lysine. The proliferative ability of olfactory ensheathing cells was detected and the cells were observed with immunofluorescence histochemical staining at 1, 3, 5, 7 days after culture. RESULTS AND CONCLUSION:Olfactory ensheathing cells could survive on the chitosan-reinforced poly-L-lactic acid film, and the cytotoxic grade wasⅠ. Morphology of the cells in the experimental group was round or oval, with little processes and the cells aggregated into groups. One day after implantation, the periphery cells of the mass extended short projections and gradual y spread outward;3 days after implantation, the cells spread and most of the cells generated projections, most of which were bipolar or tri-polar;5 days after implantation, cel processes significantly extended, most cells were bipolar and tri-polar cells, while some were oval cells and irregular triangular cells;7 days after implantation, the cel density increased, and cel processes extended. Cel morphology of the control group had similar characteristics as the experimental group. There was no obvious difference between the control and the experimental group in number, perimeter or area of the cells (P>0.05). It showed that chitosan-reinforced poly-L-lactic acid had good biocompatibility with olfactory ensheathing cells.
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BACKGROUND:To prepare glucose-responsive microcapsules which can control insulin release as changing the glucose concentration in the medium is of great significance to control the occurrence and development of diabetes mel itus. OBJECTIVE:To study the performance of glucose-responsive alginate/modified-chitosan/alginate microcapsules carryingβ-TC3 cells. METHODS:Glucose-responsive alginate/modified-chitosan/alginate microcapsules were prepared by layer-by-layer self-assembly method to evaluate the performance. And the glucose-responsive microcapsules carryingβ-TC3 cells were prepared to observe the cel proliferation within the microcapsules. RESULTS AND CONCLUSION:The integrity rate of glucose-responsive alginate/modified-chitosan/alginate microcapsules could be 95%after 48 hours oscil ation, and the hardness of microcapsules lowered, but the elasticity increased. The permeability test showed that microcapsules intercepted macromolecular substances such as bovine serum albumin and immuno-globulin G. The microcapsules could release more insulin with the increase of glucose concentration. As described above, the glucose-responsive alginate/modified-chitosan/alginate microcapsules had good mechanical strength, immunoisolation effect and glucose sensitivity. Theβ-TC3 cells entrapped in the glucose-responsive microcapsules could grow wel and the peak of cel proliferation lagged behind as compared with non-microencapsulated cells, indicating the glucose-responsive microcapsules had good biocompatibility.
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10.3969/j.issn.2095-4344.2013.25.008
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10.3969/j.issn.2095-4344.2013.25.009
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10.3969/j.issn.2095-4344.2013.25.016
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BACKGROUND:The biopsy material induced by foreign body is autologous tissue, which, in theory, avoids the role of immune rejection and destruction faced by non-autologous implants. This biology advantage has no way to comparison by synthetic and de-cel ular materials. OBJECTIVE:To explore a biotube consisting of autologous cel s and extracel ular matrix and to evaluate its structure and mechanical features. METHODS:The biotubes were prepared by embedding silicon rods as a mold intraperitoneal y. Specimens were analyzed by mechanical tests, histological observation and superficial study. RESULTS AND CONCLUSION:It was easy to excite the biotubes prepared by embedding silicon tube intraperitoneal y. The biotube mainly included col agen-rich extracel ular matrices and myofibroblasts appearing as elongated cel s with circumferential or longitudinal orientations. At 1 month of embedding, the wal was 70-250μm in thickness and had burst strength of (1 100±187) mm Hg (1 mm Hg=0.133 kPa), with perfect sewability. The biotubes, which possess the ability for wide adjustments in their shapes, are composed of autologous cel s and extracel ular matrices, and are an ideal graft for tissue engineering because they avoid immunological rejection and have sufficient mechanical strength.
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BACKGROUND:Panax notoginseng saponins promotes bone repair by improving vascular proliferation. Therefore, the scaffolds carrying panax notoginseng saponins were supposed to be used to improve bone repair at the bone defect region. However, the biocompatibility of scaffolds remains unclear. OBJECTIVE:To evaluate the biocompatibility of panax notoginseng saponins-hydroxyapatite/chitosan scaffolds. METHODS:A new bone repair scaffold has been generated by thoroughly mixtures of 0, 0.1, 1, 10 mg panax notoginseng saponins and chitosan/hydroxyapatite using in-situ composite technique and freeze-drying technique. Morphology and mechanical property of the scaffold were observed under a scanning electron microscope. (1) Cel proliferation test:rabbit bone marrow mesenchymal stem cel s of passage 3 were cultured in four kinds of drug loaded hydroxyapatite/chitosan composite material leaching liquor. Cel s normal y cultured were considered as controls. 3-(4, 5-Dimethylthiazol-2-yl) 2, 5-diphenyl tetrazolium bromide was used to measure absorbance value of cel s in each group. (2) Hemolysis test:Rabbit anticoagulated blood was added with four kinds of drug loaded hydroxyapatite/chitosan composite material leaching liquor. Absorbance values were measured using a microplate reader in each group. (3) Pyrogen test:The four kinds of drug loaded hydroxyapatite/chitosan composite material leaching liquor and saline were respectively injected into ear vein of rabbits, and the increase of rabbit body temperature was detected. RESULTS AND CONCLUSION:Drug loaded hydroxyapatite/chitosan composite material contained three dimensional porous structure of 110μm in diameter. Drug loading process of panax notoginseng saponins did not significantly affect the porosity, pore size and density of the composite material, but decreased its breaking strength and elastic modulus. The larger amount of drug loading showed a more obvious effect. Simple hydroxyapatite/chitosan composite material had good cel ular compatibility. The composite material after drug loading obviously suppressed cel proliferation, and the larger amount of drug loading showed a more obvious effect. The composite material had good blood compatibility before and after drug loading. The composite material had good pyrogen effects before and after drug loading, but accorded with acceptable quality level of pyrogen test.
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BACKGROUND:Polyurethane has good mechanical and physical characteristics and is extensively used in clinical and experimental studies, but its hydrophobicity and histocompatibility are not ideal, which limits its use in tissue engineering as a biomaterial scaffold to some extents. OBJECTIVE:To observe the hydrophilicity of polyurethane membrane grafted with silk fibroin and glutin and its compatibility with human hypopharyngeal cel s. METHODS:The changes in hydrophilicity of polyurethane membrane grafted with silk fibroin and glutin were detected by contact angle measurements. Human hypopharyngeal fibroblasts were cultured in vitro on polyurethane membrane, silk fibroin-polyurethane membrane, glutin-polyurethane membrane and tissue culture plate. Cel compatibility was compared using cytometry and cel morphology obsevation. RESULTS AND CONCLUSION:Hydrophilicity of silk fibroin-or glutin-polyurethane membranes significantly increased (Pglutin-polyurethane membrane (Pthan that on the polyurethane membrane, especial y on the silk fibroin-polyurethane membrane. These suggested that hydrophilicity and cel compatibility of silk fibroin-or glutin-polyurethane membrane were elevated.
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BACKGROUND:Shengji Yuhong col agen showed good curative effect of promoting angiogenesis and tissue healing compared with Shengji Yuhong Gao and col agen alone or gelatin alone. OBJECTIVE:To explore the curative effect and mechanism of subcutaneous implantation of Shengji Yuhong col agen in rabbits in promoting angiogenesis and repair. METHODS:Shengji Yuhong col agen as the experimental group and collagen as the control group was implanted inside the rabbit subcutaneous pockets of the back of New Zealand rabbits. The implanted samples and surrounding tissues were obtained at 3, 7, 14, 28 and 56 days fol owing surgery. Pathological sections were made and the repair of surrounding tissue was observed. Hemoglobin levels in col agen were measured. Immunofluorescence and CD34 dyeing marking method were utilized to observe capil ary angiogenesis. Western blot assay was employed to examine vascular endothelial growth factor and angiogenin-1 expression. Immunohistochemistry was used to observe the secretion of typeⅠ and Ⅲ col agen on the surrounding tissues. RESULTS AND CONCLUSION:The experimental group showed increased subcutaneous vascularization. There were reduced inflammatory exudation, granulation tissue hyperplasia, and mature fiber connective tissue at 28 days. Angiogenesis and hemoglobin contents were greater in the experimental group than in the control group (Pidentical between the experimental and control groups. However, the secretion of type Ⅲ col agen was higher in the experimental group than in the control group at 28 and 56 days (Pcol agen was lower in the experimental group than in the control group at 28 and 56 days (Pmechanisms of adjusting the protein expression of vascular endothelial growth factor and angiogenin-1. At the same time, it has the function of regulating col agen formation with better ratio of typeⅠ and type Ⅲ col agen to acquire higher quality of wound healing with reduced scar formation.
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BACKGROUND:Porous poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/calcium metaphosphate composite membranes prepared previously is too thick and uneven in holes. OBJECTIVE:To prepare the thin even porous poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/calcium metaphosphate composite membrane, and to evaluate the cytocompatibility and differentiation capacity. METHODS:Porous and nonporous, thin and even poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/calcium metaphosphate composite membranes were prepared by phase separation method. Its thickness and weight loss rate were determined. Human bone marrow mesenchymal stem cel s were cocultured with porous and nonporous poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/calcium metaphosphate composite membranes for 7 days. Ultrastructure of composite membranes was observed under the scanning electron microscopy. Surface markers of the bone marrow mesenchymal stem cel s on the composite membranes were analyzed using flow cytometry. RESULTS AND CONCLUSION:The thickness of the porous and nonporous composite membranes was (0.041 ± 0.005) mm and (0.058±0.004) mm. Weight loss rates of porous and nonporous composite membranes were respectively 19.93%and 7.64%at 24 hours. Calcium metaphosphate particles were evenly distributed in porous and nonporous composite membrane. Cel s spread entirely, showing spindle shape. Calcium metaphosphate particles were evenly distributed in porous composite membrane. Pore in porous composite membranes was also uniformly distributed, and pore size was about 2-8μm. Cel s spread entirely, showing polygonal shape with multiple tentacles. The tentacles of some cel s entered into the scaffold. CD105, CD90, CD44, CD29 and CD73 expression was detected in porous and nonporous composite membranes. There was no significant difference in cel-positive rate. Poly(3-hydroxybutyrate-co-4-hydroxybutyrate)/calcium metaphosphate composite membranes prepared in this study has good biocompatibility and could not promote cel differentiation.
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@#Biological scaffolds imitate the structure and function of extracellular matrix,and so good biocompatibility is essential for it.The materials in neural tissue engineering mainly include natural biomaterial and artificial biodegradable materials presently.This article has reviewed the biological function of materials mostly used in neural tissue engineering.