<p>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</p>

Abstract

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 remodeling.

Systematic Review of Tissue-Engineered Vascular Grafts

“…Each article analyzed in this review created its own TEVG, although there were certain materials that were commonly used, such as biodegradable polymers, or biological materials. Notably, some researchers used heparin in the design of TEVGs ( Jiang et al, 2016 ; Koobatian et al, 2016 ; Hu et al, 2017 ; Ju et al, 2017 ; Madhavan et al, 2018 ; Xu et al, 2018 ; Jin et al, 2019a ; Jin et al, 2019b ; Ran et al, 2019 ; Shi et al, 2019 ; Smith et al, 2019 ; Wang et al, 2019 ). The addition of heparin to materials prevents thrombosis and enhances biocompatibility ( Aslani et al, 2020 ).…”

Chondroitin Sulphate and Gas Foaming Concurrently Improve Articular Cartilage Regeneration in Electrospun Poly(L-lactide-co-ε-caprolactone)/Silk Fibroin Based Scaffolds

“…As a favorable natural materials, SF exhibits unique properties, such as good biocompatibility and biodegradability, which may also increase the hydrophilicity of the scaffold materials [46]. Apart from the aforementioned advantages, SF is less risky in terms of the infection compared to the other proteinaceous materials [11]. Hence, a blend of PLCL and SF was employed for the fabrication of scaffold, which has already been exploited for the regeneration of other types of tissues, such as tendons, skin, blood vessels, and nerves [47].…”

“…Nonetheless, the morphology of the membranes assembled from normal electrospinning is generally comprised of randomly dense-packed ber layers with only super cial Loading [MathJax]/jax/output/CommonHTML/jax.js pores, preventing cellular in ltration necessary to form 3D tissues [10]. Conjugate electrospinning technology, which utilizes double metal spinnerets with opposing charges and forms nanoyarn scaffolds with a highly organized interior aligned structure, has been extensively researched to fabricate nanoyarn scaffold for annulus brosus or vascular tissue engineering [11]. Meanwhile, the simultaneous operation of two nozzles promotes the e ciency of the fabrication process.…”

Insight on the endothelialization of small silk-based tissue-engineered vascular grafts

“…Recently, there have been several researches focusing on making hybrid electrospun scaffolds using both silk and synthetic polymers, like thermoplastic polyurethane or poly(ε-caprolactone)-b-poly(isobutyl-morpholine-2,5dione). [94][95][96][97][98] The idea was especially to design more biomimetic grafts taking advantage of mechanical behavior of synthetic polymers, while using silk for its good cell affinity.…”