Preparation And Investigation On Endothelialization Of Bacterial Cellulose-based Small-diameter Vascular Grafts

Objective:Preparation of small-diameter(Inner diameter<6mm)artificial blood vessels from natural polymer bacterial cellulose(BC),and then BC was modified to promote endothelial cells adhesion,and to improve the antithrombotic ability of artificial blood vessels and its long-term patency rate after in vivo implantation.Methods:The small-diameter artificial blood vessels of BC was prepared by Gluconacetobacter xylinus,with oxygen infiltration single tube method in the self-made vascular mold,the thickness and diameter of BC blood vessel were measured by vernier caliper.BC surface was then treated with 2,2,6,6-tetramethylpiperidine oxide free radical(TEMPO)to convert the hydroxyl groups into the carboxy groups.The surface was further treated by the chemical method of carbodiimide(EDC)/N-hydroxysuccinimide(NHS).Finally,the ligand molecules of endothelial cells(cell adhesion molecule REDV polypeptide)were conjugated on BC surface.Fourier transform infrared spectroscopy(FTIR)was used to characterize the surface chemical composition before and after the REDV modification.Human umbilical vein endothelial cells(HUVEC)were used to investigate the endothelialization of BC materials before and after modification,the cell proliferation and cell morphology were observed by the light microscope.Fluorescence staining method was used to investigate the spread of adherent cells to compare the cell adhesion on BC before and after REDV modification.Results:Gluconacetobacter xylinus can be used to prepare small-diameter BC artificial vessels with various inner diameter and length by the oxygen infiltration single tube method.FTIR results and HUVECs adsorption results showed that REDV is successfully fixed on BC surface.Fluorescence staining showed that HUVECs grew well on BC surface and the adherent HUVECs on the REDV modified BC surfaces were significantly higher than that of BC without modification.Conclusion:The surface modification of REDV peptide on BC is effective,the modified BC material has good biocompatibility,no cytotoxicity,and can promote the HUVEC adhesion and growth.The preparation of endothelialization of the small-diameter artificial blood vessel is expected to improve the antithrombotic ability and long-term patency rate for the small artificial vessels.