Circumferentially aligned fibers guided functional neoartery regeneration in vivo.
An ideal vascular graft should have the ability to guide the regeneration of neovessels with structure and function similar to those of the native blood vessels. Regeneration of vascular smooth muscle cells (VSMCs) with circumferential orientation within the grafts is crucial for functional vascular reconstruction in vivo. To date, designing and fabricating a vascular graft with well-defined geometric cues to facilitate simultaneously VSMCs infiltration and their circumferential alignment remains a great challenge and scarcely reported in vivo. Thus, we have designed a bi-layered vascular graft, of which the internal layer is composed of circumferentially aligned microfibers prepared by wet-spinning and an external layer composed of random nanofibers prepared by electrospinning. While the internal circumferentially aligned microfibers provide topographic guidance for in vivo regeneration of circumferentially aligned VSMCs, the external random nanofibers can offer enhanced mechanical property and prevent bleeding during and after graft implantation. VSMCs infiltration and alignment within the scaffold was then evaluated in vitro and in vivo. Our results demonstrated that the circumferentially oriented VSMCs and longitudinally aligned ECs were successfully regenerated in vivo after the bi-layered vascular grafts were implanted in rat abdominal aorta. No formation of thrombosis or intimal hyperplasia was observed up to 3 month post implantation. Further, the regenerated neoartery exhibited contraction and relaxation property in response to vasoactive agents. This new strategy may bring cell-free small diameter vascular grafts closer to clinical application.
['Zhu|Meifeng|M|', 'Wang|Zhihong|Z|', 'Zhang|Jiamin|J|', 'Wang|Lina|L|', 'Yang|Xiaohu|X|', 'Chen|Jingrui|J|', 'Fan|Guanwei|G|', 'Ji|Shenglu|S|', 'Xing|Cheng|C|', 'Wang|Kai|K|', 'Zhao|Qiang|Q|', 'Zhu|Yan|Y|', 'Kong|Deling|D|', 'Wang|Lianyong|L|']
D000818:Animals D001012:Aorta, Abdominal D001807:Blood Vessel Prosthesis D004867:Equipment Design D019544:Equipment Failure Analysis D048091:Guided Tissue Regeneration D008422:Materials Testing D008968:Molecular Conformation D009131:Muscle, Smooth, Vascular D057139:Nanofibers D018919:Neovascularization, Physiologic D051381:Rats D017207:Rats, Sprague-Dawley D012038:Regeneration D054457:Tissue Scaffolds
Vascular grafts Vascular smooth muscle cells Aligned microfiber Wet-spinning Poly(ε-caprolactone)