Multi-layer Blood Tubular Scaffold Fabrication By Electrospinning And Braiding

Recently,the incidence of blood vessel is increasing day after day,and a great deal of substitutes are needed,especially the blood vessel of inner diameter less than 6ram.However,blood cloting was found easily after the blood tubular scaffold implanted into the body,which was caused by the lack of liveness and mismatching in modulation.Therefore,suitable compatibility and long-term pourability could be obtained by tissue technique of blood vessel with EC covered inside and SMC growth outside.Based on the consideration about these,the fabrication of the blood tubular scaffold by electrospinning and braiding was given in this paper for the first time,a series of performances were tested and the best combination was shown as following.SEM showed the fiber morphology of P(LLA-CL)(50/50) nanofibers membrance with 6wt%polymer concentration was better and the diameter distribution was more uniform than that of the other material and other solution concentrations,and the average diameter was about 450nm.Nanofibers membrances of P(LLA-CL)(75/25) had better hydrophilicity and higher crystallinity but lower porosity comparing with the nanofibers membrances of P(LLA-CL)(50/50).Porosity of tubular scaffolds fabricated by two kinds of braiding material(PGLA and PLLA) was 65.18%and 64.52%respectively.100℃and 10min was confirmed as the best parameter of heat setting.The position of waves crest corresponded with the character wave crest of the groups of material in IR spectrum.Mechanic test indicated nanofibers membrance of P(LLA-CL)(50/50) had longer breaking elongation but smaller breaking stress comparing with the nanofibers membrance of P(LLA-CL)(75/25).Mechanic performance of the tube was better than that of the membrance,and the mechanic performance of compound tubular scaffold got strengthened well.Breaking stress and breaking elongation of P(LLA-CL)(75/25) was over 15MPa and 360%respectively, but those of P(LLA-CL)(50/50) got closed to 22MPa and 420%.The Cell test results proved that the P(LLA-CL)(50/50) nanofibers with 6wt%and 8wt%solution concentration could enhance the adhesion and proliferation of endothelial cells on the surface of materials,and the cells had better spreading and attachment on the nanofibers,which was proved as well by HE histology and SEM micrograghs results. The successful example with over two months pourability in the animal could set a good basis for the future of blood tubular scaffold.Multi-layer blood tubular scaffold fabricated with nanofibers membrane of P(LLA-CL)(50/50) with 6wt%polymer solution concentration as inner layer,braiding vessel of PLLA as outer layer,by heat setting at 100℃for 10min to fix the shape of the tubular scaffold with the coating of chitosan solution has full advantage by overall evaluation with all kinds of properties,which shows a potential in tissue engineering applications.