Preparation Of Decellularized Vascular Stents And Research For Constructing Tissue Engineering Bile Duct

Extrahepatic bile duct injury repair is still the challenge facing the clinical hepatobiliary surgery,because of bile duct lacking muscular layer,so the self-repair of extrahepatic bile duct is poor and relies mainly on the fibrous tissue.The current clinical treatment methods of extrahepatic bile duct repairing include the balloon expansion,bile duct stent and anastomosis of bile duct and bile intestinal anastomosis,but long-term effect are unsatisfactory.In addition,these methods give up functions of antiregurgitation and bile excretion regulation of Oddi's sphincter located and distal bile duct,thus leading to concurrent retrograde biliary tract infection and secondary biliary cirrhosis,and even increasing the risk of cholangiocarcinoma in the future.Therefore,looking for a kind of substitute to similar structure and function as the natural bile duct is a present clinical problem to be solved.Based on previous studies,this study used anionic detergent sodium dodecyl sulfate and sodium deoxycholic acid to remove the cells of rabbit's abdominal aorta.On the other hand,the nucleic acid enzyme was used to remove residual DNA and RNA to reduce the immunogenicity of decellularized vascular matrix.Finally,the pore-forming agents of acetic acid or papain were used in decellularized vascular matrix scaffold surface to form pore.The blood vessels' collagen and elastic fiber structure and elasticity strength were intact and well after decellularization by histology tests,respectively.The remaining cell and DNA are not enough to cause strong immune rejection.The adiposederived mesenchymal stem cells(ASCs)could grow,proliferate and migrate well on both sides of the decellularized vascular matrix scaffold,and the cells could grow into the stent's wall and its morphology was clear by confocal microscopy observation.After 45 days of animal experiment,the decellularized abdominal aorta was intact and filled with a small amount of floccule of lumen,and its wall was degraded partly,but still had certain elasticity.H&E and Masson staining found that a large number of cells were uniform distributed inside the bile duct wall,but without epithelial cells generated inside the wall.Through evaluation in vitro,the decellularized vascular matrix scaffold possess good porosity,biodegradable property,mechanical properties,biocompatibility,and preserve the natural extracellular matrix three-dimensional microstructure and active ingredients,which provides a good solution for bile duct tissue engineering in clinic.It also provides a certain theoretical and practical basis at a later stage for animal experiment of bile duct repairing.