Chemically modified constructs using mesenchymal stem cells derived from rat bone marrow. Credit: Iqbal, FS et al. circumstance. Health c. Mater. (2026)
The soft cartilage around bone joints gradually wears down with age, leading to arthritis. A 3D construct based on silk protein may now help repair this damaged cartilage1.
Bone morphogenetic protein (BMP) is secreted in excess in osteoporosis patients, promoting cartilage degradation. To inhibit BMP, scientists at the Indian Institute of Technology (IIT) Delhi and IIT Kanpur made a scaffold using silk-derived fibroin protein, gelatin, and a crosslinker.
The team, led by Saurabh Ghosh and Amitabha Bandyopadhyay, converted the scaffold into a signaling hub by binding a BMP inhibitor, while facilitating the signaling process (WNT/β-catenin) necessary for cartilage homeostasis. They induced osteoarthritis in rats and implanted a chemically modified silk gelatin formulation into cartilage defects in the trochrofemoral groove of the knee.
The scaffold supported the formation of new cartilage expressing cartilage-specific collagen, indicating that the cells were producing the molecular building blocks needed for strong cartilage.
The regenerated tissue lacked signs of hypertrophic cartilage and showed minimal inflammation. The new tissue closely resembles real cartilage, the soft, flexible tissue that naturally covers the ends of bones within healthy joints.
