Fabrication of Bi-Phasic Silk Fibroin/Chitosan/ 52S4.6 Bioactive Glass and Nanofibrous Gelatin-Based Macroporous Scaffold Aimed at Osteochondral Tissue Regeneration

Abstract

The development of a biphasic scaffold that simultaneously supports cartilage and subchondral bone regeneration is a very promising approach towards effective osteochondral tissue engineering. In this study, 15 wt% of 52S4.2 nanobioactive glass (NBG) incorporated silk fibroin (SF), chitosan (CH) based porous scaffold (SF 80 /CH 20 /NBG 15 ) was fabricated via a freeze-drying technique, providing a supportive bulk structure mimicking subchondral bone and then electrospun nanofibrous gelatin (GE) layer possessing fiber diameter in the range of 122.6 ± 24.60 nm onto the composite scaffold to promote cartilage tissue regeneration onto its surface. Covalent bonding between the nanofibrous gelatin and the bioactive glass/silk fibroin/chitosan scaffold was achieved using carbodiimide chemistry, ensuring strong interfacial adhesion and enhanced mechanical stability. The fabricated bi-phasic scaffold exhibited the presence of phases and functional groups of all the components of the scaffolds, i.e., SF, CH, NBG, and GE. Morphological analysis via field emission scanning electron microscopy revealed a macro porous with average porosity in the range of 117± 31 m bulk architecture with a uniform nanofibrous gelatin layer. In vitro biocompatibility and cellular response were assessed using MG-63 osteoblast-like cells through live/dead staining and MTT assays. The results demonstrated excellent cell adhesion, proliferation, and viability, indicating the scaffold’s potential to support osteochondral tissue regeneration. This biphasic scaffold presents a promising approach for the repair of articulated defects in long bone joints by providing a biomimetic environment conducive to the simultaneous regeneration of cartilage and subchondral bone tissues.