Biman Mandal holds silk cocoons in his laboratory. Telegraph picture

New Delhi, April 30: A porous sponge-like material crafted out of silk protein by a biologist at the Indian Institute of Technology, Guwahati, and his collaborators in the US may accelerate bone formation and quickly heal fractures.

The three-dimensional silk scaffolds developed by Biman Mandal at IIT-G and his colleagues at Tufts University in Boston appear to have significant advantages over conventional polymers currently used in bone repair.

The scientists have shown through laboratory and animal experiments that these scaffolds can guide the growth of fresh bone in areas of bone damage.

Tiny pores within the scaffold accept new bone cells that naturally grow during the process of healing, leading to repair of bone in a process that appears more efficient than what could be achieved through standard polymer used in bone repair.

“Human bone cells seem to like silk scaffolds better than conventional materials,” said Mandal, the lead author of a research paper describing the experimental results published today in the Proceedings of the National Academy of Sciences.

Bone healing is a natural process, but doctors routinely use hydroxyapatite or other polymer materials to guide the bone formation process — introducing the materials allows bone cells to grow in specific required directions, leading to proper healing.

“But most such conventional materials tend to absorb fluids in the body, swell, and behave like soft gels, which is not very good for the bone repair process,” Mandal told The Telegraph.

Mandal, who graduated from Calcutta’s Presidency College, turned his attention to silk while he was pursuing a PhD at IIT Kharagpur, where he learnt to extract silk protein from silkworm fibres or directly from the silk glands of non-mulberry Indian tussar silkworms.

Earlier studies by independent groups had suggested that silk scaffolds might facilitate faster generation of bones.

Mandal, while a post-doctoral research associate in the laboratory of David Kaplan, a professor of chemical and biological engineering at Tufts University, found a way to make silk scaffolds of high compressive strength.

This high strength allows the scaffolds to resist crushing at the sight of the bone repair when new bone cells exert pressure on them.

Studies on bone cells in test tubes as well as in mice suggest that the scaffolds will aid in faster repair and regeneration of bone than conventional materials, Mandal said.

Mandal and Kaplan have filed a joint patent application with the US patents office on the scaffold. The researchers are hoping to test the scaffolds in larger animals through collaborative studies with other groups.