Construction And Application Of Small-diameter Nanofiber Vascular Tissue Engineering Scaffolds

Nowadays,cardiovascular diseases have seriously threatened people's lives,but the existing vascular substitute materials can not meet the biocompatibility and mechanical properties at the same time.Therefore,the development of an ideal vascular tissue engineering scaffold has become the most important research goal of relevant researchers,and the development of small-diameter vascular scaffold with a diameter less than 6 mm has become an important work of relevant researchers.In this study,we propose to construct the small-diameter vascular scaffold by one-step method based on friction twisting core-spun electrospinning technology and apply it to vascular tissue engineering.The details are as follows:(1)In order to obtain small-diameter nanofiber vascular scaffolds,the poly-(_L-lactide-co-caprolactone)(PLCL)nanofiber core-spun yarn with nylon wire as core is prepared by one-step method based on friction twisting core-spun electrospinning technology.Then the core yarn is extracted,and the tussah silk fibroin(TSF)is grafted onto the surface of the nanofiber vascular scaffold by with low-temperature plasma treatment(LTPT).The mechanical properties of the PLCL nanofiber vascular scaffold grafted TSF is not significantly different from that of the PLCL nanofiber vascular scaffold grafted TSF.Meanwhile,the hydrophilicity,protein adsorption and blood compatibility of the PLCL nanofiber vascular scaffold grafted TSF is significantly improved compared with those without grafted TSF.The cell culture results show that the PLCL small-diameter nanofiber vascular scaffold grafted TSF is more conducive to the adhesion and proliferation of endothelial cells(VECs).(2)In order to further improve the biocompatibility and mechanical properties of mimic small-diameter vascular scaffolds,the PLCL/PCL/TSF small-diameter double-layer nanofiber vascular scaffold is prepared with poly(?-caprolactone)(PCL)/TSF as the outer layer and PLCL/TSF as the inner layer.The results show that the inner diameter and thickness of the PLCL/PCL/TSF scaffold is 1390±40?m and 524±28?m,respectively,and the burst pressure(BP)of the PLCL/PCL/TSF scaffold is increased to 8505±875 mm Hg.The results of cell culture show that the inner layer of the small-diameter double-layer vascular scaffold is beneficial to the adhesion and proliferation of VECs,and the outer layer is beneficial to the adhesion and proliferation of smooth muscle cells(SMCs).(3)In order to highly mimic the three-layer structure and function of natural blood vessels,we constructed a small-diameter three-layer nanofiber vascular scaffold with PCL/TSF/graphene oxide(GO)as the outer layer,PLCL/TSF as the middle layer,and PLCL/TSF/heparin sodium(Hep)as the inner layer.The experimental results showed that the inner diameter and thickness of the small-diameter three-layer nanofiber vascular scaffold is1372±42?m and 504±22?m,respectively.The BP of the small-diameter three-layer nanofiber vascular scaffold is increased to 12020±858 mm Hg.The cell culture results showed that the inner layer of the small-diameter three-layer nanofiber vascular scaffold promoted the adhesion and proliferation of VECs,and the outer layer promoted the adhesion and proliferation of smooth muscle cells(SMCs).Therefore,the successfully prepared the small-diameter three-layer nanofiber vascular scaffold has great application potential in the clinical treatment of vascular diseases.