Researchers at the Indian Institute of Technology-Madras (IIT-M) have developed a nano-coated magnesium alloy to repair bone fractures in rabbits.
The team is now exploring if the same method can be used to repair bones in others, including humans.
Magnesium is the fourth abundant metal in the body and is known to accelerate healing of bones. Magnesium’s biocompatibility and biodegradability also makes it difficult to use in bone repair.
Mukesh Doble, professor in the Department of Biotechnology, led the team, comprising post-doctoral research associate Govindaraj Perumal; Boopalan Ramasamy from Christian Medical College; A. Maya Nandkumar from Sree Chitra Tirunal Institute for Medical Sciences and Technology; D. Sivaraman of Sathyabama Institute of Science and Technology and R. Selvaraj from the Bioscience Research Foundation. Their research was published in the journal Nanomedicine and a patent has been filed.
Mr. Doble said bones of the arm, leg and thigh are the long bones, and while small fractures can be treated with plates and rods segmental, defects such as fractures more than 5 cm take a longer time to heal and need support. At present, titanium is used but it does not degrade and leads to stress shielding as it has mechanical strength much more than the bone, he said.
Magnesium, on the other hand, can degrade slowly and is reabsorbed. Its mechanical properties are closer to that of the bone. However, the problem is that magnesium degrades fast. To slow down the degradation and match it to the growth of the new bone, it is coated with a slowly degrading polymer. The researchers developed and used AZ31 alloy of magnesium to develop the mesh cage implants, and coated it with the polycaprolactone and nano-hydroxyapatite. This mesh was used to heal the bone defect in the femur of rabbits.