Fabrication and characterization of small-caliber nanofibrous vascular scaffolds with sustained release of endothelial cell derivatives and heparin

Ying Wang¹Yawen Wang²Jiaoyan Qiu¹Jing Wang¹Yuanfei Wang¹Manfei Fu¹Tong Wu^1*

• ¹Qingdao University, Qingdao, China
• ²University of Health and Rehabilitaiton Sciences, Qingdao, China

Cardiovascular diseases are a leading cause of mortality, and artificial blood vessels as an alternative strategy are extensively used in clinical settings. Due to the underlying potential for thrombus formation and intimal hyperplasia, the clinical applications of small-caliber (< 6 mm) artificial vessels are limited. Promoting rapid endothelialization and enhancing anticoagulant ability are pivotal approaches to achieve long-term patency of small-caliber artificial vessels. In this work, coaxial electrospinning was employed to fabricate biocompatible PCL-ECd nanofibers with a core-shell structure. PCL was selected as the shell layer to provide mechanical support, and 30% ECd was screened as the core layer to accelerate endothelialization. Although PCL-ECd exhibited superior hemocompatibility, its anticoagulant efficiency was low, failing to meet clinical requirements. Consequently, the addition of 10% Hep in the core layer endowed the P-E/H nanofibers with the desired anticoagulant properties. And coaxial-emulsion electrospinning was introduced to enable a sustained release profile of ECd and Hep from P-E/H. The P-E/H enhanced cellular proliferation and suggested superior hemocompatibility and anticoagulant effects. The in vitro blood flow patency of a further processed P-E/H vascular scaffold with a 4 mm diameter was evaluated using a closed-loop system, indicating the absence of any clot or thrombus. This study proposes a new strategy for developing small-caliber vascular scaffolds.