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

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°±5.22° 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.

Graphical abstract