Hybrid Nano-Micro Scaffolds for Cartilage Tissue Engineering: Integrating PCL-DWJM-MWCNTs on Chemically Modified Silk Fibroin

Abstract

Nano-micro scaffolds fabricated based on electrospinning and textile methods. The solution containing polycaprolactone (PCL), decellularized Wharton's jelly matrix (DWJM) and functionalized multi-walled carbon nanotubes (MWCNTs) were electrospun on the silk fibroin treated with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide/N-hydroxysuccinimide (NHS/EDC). Hybrid scaffolds (with/without MWCNTs) were compared with each other in terms of physical, chemical, mechanical, bioactivity, and biological properties. Cross-sectional view showed that the nanofibers are well seated on the NHS/EDC-treated microfibers (T-fibroin). The increase of free functional groups decreased the contact angle to 70.51 degrees +/- 5.22 degrees and improved the tensile strength to 33.84 +/- 3.6 MPa. The presence of NHS/EDC leads to the formation of crosslinks in the fibroin polymer network, resulting in enhanced tensile strength of T-Fibroin compared to untreated fibroin (U-Fibroin). The crosslinks within the fibroin structure and the presence of MWCNTs enhanced the crystallinity of the scaffold structure while reducing its degradation rate (1.73). The presence of carboxyl groups in the structure of MWCNTs, DWJM and T-Fibroin improved bioactivity and enhanced the chondrocytes' viability on the scaffold. The findings suggest using DWJM and surface chemical modification of fibroin knitted fabric is a promising approach in advancing nano-micro scaffolds. PCL-DWJM-MWCNTs/Fibroin Silk scaffold can served as a basic study for articular cartilage regeneration.