A novel nanocomposite developed by researchers from CSIR-National Metallurgical Laboratory (CSIR-NML) has shown potential to be used as a regenerative bone graft especially in regions which need high strength. The nanocomposite was synthesised through a simple and cost-effective route. The composite contains carboxymethyl cellulose, gelatin and hydroxyapatite, with the hydroxyapatite in nanoscale (25-10 nm size).
The bone graft to be used in load-bearing application must match the strength of the natural bone. So the researchers evaluated the strength and elasticity of the nanocomposite and found it to be in the same range as human cancellous and cortical bone.
“All bone grafts need to be steam sterilised before use. So it is essential that the substance can withstand at least 120 degree C. Our new polymer nanocomposite is thermally stable up to 200 degree C. It is biodegradable and also accelerates the formation of new bone apatite under simulated body fluid,” explains Chandrani Sarkar, PhD scholar at the institute and first author of the paper published in Journal of Material Science.
In vitro studies
They also examined the biocompatibility and proliferation of the human bone cell line (MG-63) cells in the presence of the nanocomposite. The human cells were found attached and had spread well on the surface of the nanocomposite indicating that they were well suited for cell growth and proliferation. They also observed that the nanocomposite accelerated the bone cell line for new bone tissue formation.
In vivo tests need to be carried out to get a full understanding of the nanocomposite.
There are several options available for replacement of damaged/diseased bones such using patient’s own bone, donor’s bone and metallic implants.
The risk of transferring diseases and chances of biological rejection from host body are very high in the case of bones transplanted from others (allo-graft). Metallic implants have high mechanical strength and mismatch with natural bone causing stress shielding and bone loosening which may damage or fracture adjacent bones.
“The compressive strength and modulus of our nanocomposite is in the range of human bone. So there is no risk of damage to adjacent bones after implantation. Importantly, the nanocomposite has regenerative property, with time it will be absorbed inside the body and new bone will be formed in that place. Unlike metallic implants, there is no need to take out our implants,” explains Sarkar in an e-mail to The Hindu.
“We have already transferred know-how to industry and they are using our products,” says Prof. Subhadra Garai, senior scientist and corresponding author at the Advanced Materials and Processing Division, CSIR-NML.
