Promoting endothelialization on new tissue-engineered vascular grafts by biomacromolecule immobilization

Introduction Coronary and peripheral artery diseases are the most common cardiovascular diseases. Owing to the shortage of healthy autologous blood vessels for grafting in various cardiovascular diseases and the low patency rate of synthetic vascular grafts, tissue engineering is a promising approachfor the replacement of damaged vessels. Rapid in-situ endothelialization of the vascular grafts remains as a challenge in the vascular grafts. Objectives We aimed to develop a new polyurethane and improve the surface scaffold for rapid in-situ endothelialization. Methods We have developed the new tissue engineered small-diameter vascular grafts by the compression molding and dip coating methods. The surface of polyurethane constructs were then functionalized by aminolysis and immobilized biomacromolecules. The scaffolds were then characterized through attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscope (SEM), AFM (atomic force microscope), water contact angle and mechanical test. Results The functional groups in the samples were confirmed using ATR-FTIR. After the immobilization of biomacromolecules, the surface roughness of the constructs increased. Furthermore, the wettability of scaffolds promoted in the modified scaffolds. The results of mechanical test demonstrated that the tensile strengths and strains of modified scaffolds were close to the native coronary artery. The surface modifications also led to the suitable cell attachment and function on the scaffolds so that a confluent layer of endothelial cells was formed on the biomacromolecule-immobilized vascular grafts. Conclusion This research demonstrated that the new modified vascular grafts supported endothelialization and can be considered as a candidate material for vascular tissue engineering.

Keywords:

Tissue engineering , Endothelialization , Polyurethane , Surface modification , Vascular graft