Fabrication and Evaluation of PCL/Collagen I-Based 3D Nanofibrous Scaffolds by Mold-Assisted Electrospinning for Tissue Engineering and Regenerative Medicine

Abstract

Three-dimensional (3D) nanofibrous scaffolds exhibit superior biomimetic potential by structurally and functionally emulating the native extracellular matrix (ECM) microenvironment, a critical determinant for successful tissue repair and regeneration. While conventional two-dimensional (2D) electrospun scaffolds provide nanoscale fibrous architectures, they do not have the necessary complexity to mimic cell-matrix interactions observed in vivo. This limitation is due to the current electrospinning methods, which mainly create flat structures instead of real 3D matrices that have controlled porosity and interconnectivity. This study developed a new method using a mold to produce three-dimensional (3D) nanofibrous scaffolds made of polycaprolactone (PCL) and collagen type I (Col I) that mimic natural structures. For this purpose, a three-dimensional aluminum template was engineered to directly fabricate nanofibrous scaffolds via electrospinning, bypassing supplementary processing stages. Subsequent comprehensive analysis encompassed physicochemical properties, biocompatibility, and critical performance metrics necessary for tissue engineering applications. Mold-assisted electrospinning produced nanofibers (40-60 nm) and microfibers (0.2-0.7 mu m). Porous scaffolds with nano- (200-500 nm) and micropores (15-25 mu m) with high pore interconnectivity allow cell infiltration, migration, and nutrient/gas exchange. PCL/Col I nanofibrous scaffolds presented hydrophilic behavior, surface roughness and extended surface area, and favorable tensile strength and Young's modulus. PCL/collagen I-based 3D nanofibrous scaffolds exhibited suitable cell attachment and a promoting effect on the proliferation and osteogenic differentiation of adipose-derived mesenchymal stem cells (ADSCs). Osteogenic differentiation capability of cells on the nanofibrous scaffolds was analyzed by alkaline phosphatase activity and calcium content assay. Results showed higher alkaline phosphatase activity and calcium deposition mineralization than the 2D structures and control groups. These 3D constructs with admirable processability and compatibility with cells are promising candidates to be utilized as versatile platforms for tissue engineering.