IIT-M researchers develop nano-coated magnesium alloy to fix bone fracture

Encouraged by the results after experimenting in rabbits, the research team, which is partnering with several other institutions, is planning to study medical applications of nano-coated magnesium alloys in other animals and for repairing human bones.

Alloys of magnesium are being considered as a good option for orthopaedic applications as magnesium is biocompatible, biodegradable, and has other important mechanical properties. Magnesium is the fourth abundant metal in the body and is known to accelerate the healing of bones.

However, the use of magnesium alloys in bone repair is restricted due to a few issues. These issues have given a major push to the field of synthetic bone biomaterials where materials such as hydroxyapatite, calcium phosphate, and titanium, among others, are being used for filling the bone gaps.

Highlighting the key aspects of this research, Prof. Mukesh Doble, Department of Biotechnology, IIT Madras, said, “Bones such as the fore-arm, back-arm, leg and thigh which are almost one-foot-long are called ‘long bones’ in the body. Small fractures or defects can be treated with plates and rods. Fractures longer than 5 cm are called long bone segmental defects, which take a long time to heal and need some sort of support. Titanium mesh cage is placed in the gap which helps to heal and stabilize the bone. But it does not degrade and so remains in the body permanently. It also leads to stress shielding since it has mechanical strength much larger than the bone.”

According to him, the researchers found that the rabbit femur implanted with the coated magnesium alloy showed bone formation and also bridged the defect region.

The team emphasizes that this was possible due to the biocompatible nature of polycaprolactone and nano-hydroxyapatite which ensured good recovery without any adverse reactions such as ‘fibrosis’. The team is exploring funding opportunities to further test this nano-coated magnesium alloy in repairing bone defects in large animals.