Design and preparation of polyurethane-collagen/ heparin-conjugated polycaprolactone double-layer bionic small-diameter vascular graft and its preliminary animal tests  

作　　者：LU Guang CUI Shi-jun GENG Xue YE Lin CHEN Bing FENG Zeng-guo ZHANG Jian LI Zhong-zhi 

机构地区：[1]Department of Pediatric Cardiac Surgery, Beijing Children Hospital, Capital Medical University, Beijing 100045, China [2]Department of Vascular Surgery, Xuanwu Hospital, Capital Medical University, Beijing 100053, China [3]School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China

出　　处：《Chinese Medical Journal》2013年第7期1310-1316,共7页中华医学杂志（英文版）

摘　　要：Background People recently realized that it is important for artificial vascular biodegradable graft to bionically mimic the functions of the native vessel. In order to overcome the high risk of thrombosis and keep the patency in the clinical small-diameter vascular graft （SDVG） transplantation, a double-layer bionic scaffold, which can offer anticoagulation and mechanical strength simultaneously, was designed and fabricated via electrospinning technique. Methods Heparin-conjugated polycaprolactone （hPCL） and polyurethane （PU）-collagen type I composite was used as the inner and outer layers, respectively. The porosity and the burst pressure of SDVG were evaluated. Its biocompatibility was demonstrated by the 3-（4,5-dimethyl-2-thiazol）-2,5-diphenyl-2H tetrazolium bromide （MTT） test in vitro and subcutaneous implants in vivo respectively. The grafts of diameter 2.5 mm and length 4.0 cm were implanted to replace the femoral artery in Beagle dog model. Then, angiography was performed in the Beagle dogs to investigate the patency and aneurysm of grafts at 2, 4, and 8 weeks post-transplantation. After angiography, the patent grafts were explanted for histological analysis. Results The double-layer bionic SDVG meet the clinical mechanical demand. Its good biocompatibility was proven by cytotoxicity experiment （the cell＇s relative growth rates （RGR） of PU-collagen outer layer were 102.8%, 109.2% and 103.5%, while the RGR of hPCL inner layer were 99.0%, 100.0% and 98.0%, on days 1, 3, and 5, respectively） and the subdermal implants experiment in the Beagle dog. Arteriography showed that all the implanted SDVGs were patent without any aneurismal dilatation or obvious anastomotic stenosis at the 2nd, 4th, and 8th week after the operation, except one SDVG that failed at the 2nd week. Histological analysis and SEM showed that the inner layer was covered by new endothelial-like cells. Conclusion The double-layer bionic SDVG is a promising candidate as a replacement of native small-diameter vasculaBackground People recently realized that it is important for artificial vascular biodegradable graft to bionically mimic the functions of the native vessel. In order to overcome the high risk of thrombosis and keep the patency in the clinical small-diameter vascular graft （SDVG） transplantation, a double-layer bionic scaffold, which can offer anticoagulation and mechanical strength simultaneously, was designed and fabricated via electrospinning technique. Methods Heparin-conjugated polycaprolactone （hPCL） and polyurethane （PU）-collagen type I composite was used as the inner and outer layers, respectively. The porosity and the burst pressure of SDVG were evaluated. Its biocompatibility was demonstrated by the 3-（4,5-dimethyl-2-thiazol）-2,5-diphenyl-2H tetrazolium bromide （MTT） test in vitro and subcutaneous implants in vivo respectively. The grafts of diameter 2.5 mm and length 4.0 cm were implanted to replace the femoral artery in Beagle dog model. Then, angiography was performed in the Beagle dogs to investigate the patency and aneurysm of grafts at 2, 4, and 8 weeks post-transplantation. After angiography, the patent grafts were explanted for histological analysis. Results The double-layer bionic SDVG meet the clinical mechanical demand. Its good biocompatibility was proven by cytotoxicity experiment （the cell＇s relative growth rates （RGR） of PU-collagen outer layer were 102.8%, 109.2% and 103.5%, while the RGR of hPCL inner layer were 99.0%, 100.0% and 98.0%, on days 1, 3, and 5, respectively） and the subdermal implants experiment in the Beagle dog. Arteriography showed that all the implanted SDVGs were patent without any aneurismal dilatation or obvious anastomotic stenosis at the 2nd, 4th, and 8th week after the operation, except one SDVG that failed at the 2nd week. Histological analysis and SEM showed that the inner layer was covered by new endothelial-like cells. Conclusion The double-layer bionic SDVG is a promising candidate as a replacement of native small-diameter vascula

关 键 词：small-diameter vascular graft heparin-conjugated polycaprolactone double-layer scaffold BIONIC in vivo implant 

分 类 号：TQ577.42[化学工程—精细化工] TS59[轻工技术与工程—皮革化学与工程]