| Tendon tissue engineering can provide an effective way for tendon defect and tendon injuries.Scaffolds play an important role in tendon tissue engineering.Composite scafffolds is the focus of research and trends with tendon tissue engineering.Polyvinyl alcohol(PVA) is catalyzed by the alkaline hydrolysis products of glycolysis,which is in the field of medical material of great value.Wild Antheraea Pernyi Silk Fibroin which is from natural silk fibers.The order of the main amino acids in silk fibroin sequence was:alanine(Ala)>glycine(Gly)>serine(Ser)>tyrosine(Tyr),it also have rich aspartic acid(Asp) and arginine(Arg).The (arginine(Arg)-glycine(Gly)-aspartic acid(Asp)RGD tripeptide sequence which is better for cell adhesion.The fibroin fibers was used in tissue engineering tendon, the results was showed that silk fibroin scaffold for tendon tissue engineering was feasible,silk can promote the defect of rabbit calcaneal tendon.But the experiment also found that,the degradation of silk fibers was poor. PVA/WSF composite nanofibers were prepared by electrospinning,it could get a comprehensive performance for tendon tissue engineering scaffold to meet the requirements of the new biological material.This results were as follows:1.PVA/WSF composite nanofiber scaffold was preparation by electrospinning,the best ratio of the components were:the mass ratio of PVA/WSF was 90/10,the concentration of spinning solution was 11%,the solidification distance was 20cm,the voltage of the electrospinning was 80kV,the extrusion rate was 5mL/h, the spinning temperature was 45℃.Under these conditions, the thickness of fiber diameter was uniform.Fourier transform infrared spectra indicated that PVA and WSF was physically blended without new chemical bonds.2.The degradation of PVA/WSF scaffold was investigated by the residual weight percentage.The results showed that the degradation rate of PVA/WSF scaffold in vitro was in a certain extent,the enzyme rate was faster than the hydrolysis rate.The results of degradation in vivo show that:the degradation of PVA/WSF nanofiber scaffold was better than PVA. 3.The separation of tendon cells with SD primary neonatal rat tail was successful.The cytotoxicity of PVA/WSF was investigated by MTT. MTT results showed that compared with PVA, the extracts of PVA/WSF can promote the growth and proliferation of cells. The cytotoxicity evaluation criteria showed that the grade of PVA/ WSF composite was in 0-1 toxicity rating.Determination of cell growth curve showed that the proliferation rate of tendon cells in the PVA/WSF was faster than PVA.The cells was cultured in PVA/WSF and PVA, which was found by SEM and HE staining.The results were that the composite scaffold scaffold were more favorable than PVA,tendon cells could form multi-layer surface structure,and the cells in the composite nanofiber scaffolds was showed growth in a certain directions. Immunohistochemistry results showed that tendon cells in each group could stand on the normal expression of collagen type I, but PVA/WSF scaffolds which contain the RGD sequence showed more collagen typeⅠ, this indicate that the presence of RGD sequence cells can improve the compatibility of PVA scaffold is conducive to the seed cell adhesion and growth factor expression.4.The histocompatibility of PVA/WSF and PVA were evaluation with SD rats,the inflammatory response and toxicity were observed that after 28d the degradation of collagen has been completely by new connective tissue.The area out of raw materials has been replaced.According to histological evaluation criteria,PVA/WSF was in grade I-II-class.The inflammatory response compared with the control group level in the following order:PVA>PVA/WSF>collagen>control group.Histocompatibility order of the merits was collagen>PVA/WSF composite scaffold>PVA scaffold. The results show that the PVA/WSF composite scaffolds have good biocompatibility.5.Animal tendon defect model was successfully constructed.The artificial tendon with mechanical properties was preparaed by a certain braided. |
PDF Full Text Request