Research Highlight

Silk protein hydrogels repair cartilage

doi:10.1038/nindia.2016.137 Published online 20 October 2016

Researchers have created new hydrogels that can help grow cartilage cells, potentially useful for replacing damaged cartilage tissues in patients suffering from bone diseases such as osteoarthritis1.

Because cartilage tissues lack blood vessels, neurons and lymphatic system, they cannot heal themselves. Current approaches such as arthroscopic repair and soft tissue grafts for repairing worn-out cartilage are expensive and inefficient. 

To develop a better cartilage-repair process, the researchers blended silk protein fibroin from mulberry and non-mulberry silkworms with polysaccharide agarose to make the hydrogels. They then tested their efficiencies in growing cartilage cells, using cultured porcine cartilage cells.

The microporous hydrogels enhanced cell migration from the pores on the surface towards the internal pores. The pores also played vital roles in ferrying oxygen and nutrients to the growing cells, allowing their attachment and proliferation.

The hydrogels swelled properly and retained their shapes even after being immersed in aqueous solutions which facilitates cell cuture and implantation processes.

Two weeks after cell culture on the hydrogels, the cartilage cells secreted sulfated glycosaminoglycans and collagen, key ingredient sthat form the extracellular matrix of cartilage tissues. They also expressed cartilage-specific marker genes, proving that the hydrogels can support and stimulate cell growth and cellular matrix synthesis.

“The hydrogels, loaded with cartilage cells and growth factors, can be implanted for regenerating cartilage tissues in diseased bone joints,” says lead scientist, Biman Mandal from the Indian Institute of Technology, Guwahati. 




1. Singh, Y. P. et al. Potential of agarose/silk fibroin blended hydrogel for in vitro cartilage tissue engineering. ACS. Appl. Mater. Interfaces. 8, 21236-21249 (2016)