| Small caliber artificial blood vessels become the bottleneck of vascular tissue engineering products for high graft failure rate due to thrombosis and stenosis,and thrombosis is the major obstacle of small caliber vascular tissue engineering.In recent years,chitosan/polyvinyl alcohol(CS/PVA)scaffolds aroused extensive attention in skin tissue engineering because of its good biocompatibility and biodegradability,its mechanical properties are close to that of small diameter vascular,while had it not been used in vascular tissue engineering for its poor effect of inhibiting thrombosis.It is found that fucoidan(F)has good effect of anti coagulation,anti thrombosis,immune regulation,anti inflammation and so on.Therefore,to exert advantages of the two kinds of material,we prepared F/CS/PVA artificial blood vessel scaffold by electrospinning,study the property of the composite material when it was electrospun and investigated the feasibility that the composite material used in vascular tissue engineering by improving blood compatibility of CS/PVA with fucoidan.In this paper,the extraction process of fucoidan from kelp was optimized firstly,and then F/CS/PVA artificial vascular scaffolds were prepared by electrospinnin with fucoidan and CS/PVA,the preparation process of the scaffolds were optimized and their characterization were evaluated.Finally,biocompatibility of the electrospun scaffolds were evaluated by blood agglutination test,blood platelet adhesion test and cytotoxicity test.The results show that the method of hot water extraction was the best extraction method of polysaccharide from kelp,under the optimal conditions,the yield was 12.5% and the content of polysaccharide is 52.7%;When the mass ratio of CS/PVA is 1:5,the concentration of fucoidan is 1.5%,the injection speed is 0.2m L/h,the receiving distance is 10 cm and the voltage is 13 k V,the prepared F/CS/PVA tubular scaffold has uniform surface and interdigitated pore structure,which suggested that fucoidan composite material can beprocessed by electrospining;The tensile strength of electrospun scaffold was 798±58k Pa the elongation at break was 37±2.2%,the value is close to that of normal human blood vessels,as indicated that the mechanical properties of electrospun scaffold can meet the requirements of artificial blood vessel;Besides,the swelling tate of212±9.6%,porosity of 90.59±0.65%,BSA release rate of 55.6±2.7%at 120 h and degradation rate of 65.11±2.79% after 21 days showed the feasibility of F/CS/PVA scaffolds using in vascular tissue engineering;In blood agglutination test,TT was extended to 66.2s,APTT was extended to 79.8s,which indicated that small quantities of fucoidan(1.5%)can solve the problem of thrombosis in vascular scaffolds;The result of platelet adhesion test suggested that fucoidan can reduce the platelet adhesion rate of scaffolds,and reduce the incidence of thrombosis further in small diameter vascular scaffolds;The hemolysis rate of 2.73±0.59% also showed the good blood compatibility of scaffolds;The cell viability of85.8±7.2% in MTT test showed that 1.5%F/CS/PVA scaffolds have low cytotoxicity,and with the fucoidan content increasing,the relative growth rate of cells increased,which suggested that fucoidan can promote cell growth to some extent and improved the biocompatibility of scaffold further.In summary,this study confirmed that F/CS/PVA artificial vascular scaffolds can be constructed by electrospinning,and the prepared 1.5%F/CS/PVA electrospun scaffolds have similar mechanical properties to natural blood vessels and excellent anti-clotting properties,good cell compatibility and blood compatibility.All of these indicated that 1.5%F/CS/PVA electrospun vascular scaffolds have great potential application in vascular tissue engineering. |
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