Evaluation of a simple off-the-shelf bi-layered vascular scaffold based on poly(L-lactide-co-ε-caprolactone)/silk fibroin in vitro and in vivo

Abstract

Dawei Jin,1,* Junfeng Hu,2,* Dekai Xia,1 A’li Liu,3 Haizhu Kuang,2 Jun Du,3 Xiumei Mo,2 Meng Yin11Department of Cardiothoracic Surgery, Shanghai Children‘s Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, People’s Republic of China; 2State Key Lab for Modification of Chemical Fibers and Polymer Materials, College of Chemistry, Chemical Engineering and Biotechnology, Donghua University, Shanghai 201620, People’s Republic of China; 3Imaging Diagnosis Center, Shanghai Children‘s Medical Center, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, People’s Republic of China*These authors contributed equally to this work Purpose: In the field of small-caliber vascular scaffold research, excellent vascular remodeling is the key to ensuring anticoagulant function. We prepared an off-the-shelf bi-layered vascular scaffold with a dense inner layer and a loose outer layer and evaluated its remodeling capabilities by in vivo transplantation.Materials and Methods: Based on poly(L-lactide-co-ϵ-caprolactone) (PLCL), silk fibroin(SF), and heparin (Hep), PLCL/SF/Hep bi-layered scaffolds and PLCL/Hep bi-layered scaffolds were prepared by electrospinning. The inner layer was a PLCL/SF/Hep or PLCL/Hep nanofiber membrane, and the outer layer was PLCL/SF nano yarn. The in vitro tests included a hydrophilicity test, mechanical properties test, and blood and cell compatibility evaluation. The in vivo evaluation was conducted via single rabbit carotid artery replacement and subsequent examinations, including ultrasound imaging, immunoglobulin assays, and tissue section staining.Results: Compared to the PLCL/Hep nanofiber membrane, the hydrophilicity of the PLCL/SF/Hep nanofiber membrane was significantly improved. The mechanical strength met application requirements. Both the blood and cell compatibility were optimal. Most importantly, the PLCL/SF/Hep scaffolds maintained lumen patency for 3 months after carotid artery transplantation in live rabbits. At the same time, CD31 and α-SMA immunofluorescence staining confirmed bionic endothelial and smooth muscle layers remodeling.Conclusion: Using this hybrid strategy, PLCL and SF were combined to manufacture bi-layered small-caliber vascular scaffolds; these PLCL/SF/Hep scaffolds showed satisfactory vascular remodelingKeywords: silk fibroin, small-caliber, vascular remodeling, hybrid strategy

Keywords

• silk fibroin
• small-caliber
• vascular remodeling
• hybrid strategy