Gas foaming of electrospun poly(L-lactide-co-caprolactone)/silk fibroin nanofiber scaffolds to promote cellular infiltration and tissue regeneration

Yujie Chen,Zihao Jia,Muhammad Shafiq,Xianrui Xie,Xianghao Xiao,Rita Castro,João Rodrigues,Jinglei Wu,Guangdong Zhou,Xiumei Mo

doi:10.1016/j.colsurfb.2021.111637

Abstract

Electrospun nanofibers emulate extracellular matrix (ECM) morphology and architecture; however, small pore size and tightly-packed fibers impede their translation in tissue engineering. Here we exploited in situ gas foaming to afford three-dimensional (3D) poly(L-lactide-co-ε-caprolactone)/silk fibroin (PLCL/SF) scaffolds, which exhibited nanotopographic cues and a multilayered structure. The addition of SF improved the hydrophilicity and biocompatibility of 3D PLCL scaffolds. Three-dimensional scaffolds exhibited larger pore size (38.75 ± 9.78 μm2) and high porosity (87.1% ± 1.5%) than that of their 2D counterparts. 3D scaffolds also improved the deposition of ECM components and neo-vessel regeneration as well as exhibited more numbers of CD163+/CCR7+ cells after 2 weeks implantation in a subcutaneous model. Collectively, 3D PLCL/SF scaffolds have broad implications for regenerative medicine and tissue engineering applications.

Highlights

Electrospinning has gathered significant attention from the research community owing to its potential to afford extracellular matrix (ECM) mimetic nanofibers
Because NaBH4 solution was absorbed into poly(L-lactide-co-ε-caprolactone)/silk fibroin (PLCL/SF) nanofiber membrane and followed by the generation of H2 gas bubbles in situ, which rearranged the fibers into a 3D-like architecture by exerting pressure on the surrounding fibers, resulting in a multilayered structure of the 3D scaffold
The swelling degree of 2D PLCL/SF nanofiber scaffolds (2DNFS) and 3D nanofiber scaffold (3DNFS) was measured by incubating the scaffolds in PBS solution. 3DNFS showed higher swelling degree than that of 2DNFS (Fig. S1, supporting information). 3DNFS possessed loosely-packed multi-layered structure, leading to more voids inside the 3DNFS and a higher swelling degree compared to tightly-packed layers of 2DNFS with small pore between nanofiber

Summary

Introduction

Electrospinning has gathered significant attention from the research community owing to its potential to afford extracellular matrix (ECM) mimetic nanofibers. It is pertinent to devise an innovative strategy to afford electrospun scaffolds with improved porosity and loosely-packed fibers structure, while exhibiting nanofibrous morphology and an appropriate pore size [3]. To circumvent these limitations and afford 3D scaffolds, an array of approaches, including the use of sacrificial fibers, electrospraying technique, post-treatment of fibers as well as liquid- and templateassisted collection have been put forwarded [4–8]. These ap proaches face several shortcomings, including the use of special instrumentation, lengthy and time-consuming experimental procedures, and poor control over the morphology of the scaffolds, necessitating the simple, controllable, and effective method for generating 3D scaffolds

Objectives

Results

Conclusion