Incorporating hydroxyapatite and micro-nano-fibrous structure into cardiovascular scaffold for improved hemocompatibility and endothelialization

Abstract

The scaffolds used for treatment of cardiovascular disease generally require good hemocompatibility and endothelialization. Incorporating the bioactive material and the formation of biomimetic structure are the main effective methods to ensure good hemocompatibility and rapid endothelialization. Herein, in this work, the bacterial cellulose (BC)/hydroxyapatite (HAp)-polyethersulfone (PES) scaffold (BC/HPES) is developed by the combination of electrospinning of PES solution with nano HAp and step-by-step in situ biosynthesis. The scaffold is composed of PES microfibers loaded with HAp (fiber diameters ranging from 0.8 to 2.6 µm) and BC nanofibers with diameters of 20 to 60 nm. Hemocompatibility results show that the micro-nano fiber structure is the main factor to influence the platelet adhesion number, hemolysis rate, and various static clotting times of the scaffolds, while the dynamic clotting time and plasma recalcification time (PRT) are affected by both the micro-nano fiber structure and HAp. Thus, the BC/HPES scaffold shows the longest dynamic clotting time (72 ± 3 min) and PRT (5.8 ± 0.3 min) among all the scaffolds. Moreover, this scaffold exhibits improved endothelialization over PES, HPES, BC, and BC/PES scaffolds according to the results of cell morphology, NO release amounts, and expression levels of platelet endothelial cell adhesion molecule (CD31), vascular endothelial growth factor (VEGF), and von Willebrand factor (VWF). This scaffold with micro-nano-fibrous structure and loaded with HAp in microfibers shows the improved hemocompatibility and endothelialization and thus has high potential for cardiovascular disease treatment.