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Study of tissue-engineered small vascular graft sheathed with nano poly (1,3-diamino-2-hydroxypropaneco-polyolsebacate) on adventitia and coated with heparin on intima

LIU Jun, ZHANG Xiao-ying   

  1. Department of Cardiothoracic Surgery, Third Affiliated Hospital, Soochow University, Changzhou 213003, China
  • Online:2017-03-28 Published:2017-03-30

Abstract:

Objective · To develop a new hybrid tissue-engineered vascular graft (HTEV) with excellent mechanical properties and biological functions. Methods · Decellularized rat aortas (DRAs) were prepared. Then, electrospinning nano poly (1,3-diamino-2-hydroxypropane-co-polyolsebacate) (ES-APS) was used to sheathe DRAs in order to improve the mechanical properties. After that, the intima of HTEV scaffold was modified with heparin coating. HTEVs were implanted in rat models in vivo to evaluate their biological functions. Six weeks later, vascular ultrasound and micro-CT angiography were carried out. Results · The donor aortic vessels were successfully decellularized. The total DNA content of DRA group [(115.4±10.9) ng/mg] significantly decreased compared with natural aorta group [(398.6±14.6) ng/mg] (P=0.000). But collagenous fibers and elastic fibers of decellularized vessels were severely injured. Mechanical tests of scaffolds showed that ES-APS significantly enhanced the mechanical properties. The wall thickness [(187±11) μm], suture retention strength [(0.51±0.06) N] and burst pressure [(2 103±232) mmHg] of HTEV group all significantly increased compared with DRA group (P<0.01). Heparin coating modification of HTEV significantly reduced the number of adhesive platelets. Vascular ultrasound and micro-CT angiography showed all grafts were totally patent 6 weeks after implantation in rat models. ES-APS sheath successfully prevented the occurrence of vasodilation and aneurysm formation. Conclusion · DRA sheathed with ES-APS on adventitia and coated with heparin on intima is a new kind of HTEV, which possesses increased tensile strength and improved biocompatibility.

Key words: tissue-engineered vascular graft, decellularization, electrospinning, poly (1,3-diamino-2-hydroxypropane-co-polyolsebacate), heparin coating