Iranian researchers from Kashan University synthesized a nanocomposite which can be used in tissue engineering.

The biocompatible nanocomposite is highly strong and no toxic or harmful solvent has been used in its production.

Hydroxyapatite is one of the most valuable biocompatible compounds in the production of bone implants. However, hydroxyapatite cannot be used solely due to its low strength and fragility. Composites of hydroxyapatite are made and used to increase its mechanical properties.

In this research, a nanocomposite was made of graphene oxide/hydroxyapatite/chitosan that can be an appropriate bed for the growth of bones. This nanocomposite has better biocompatibility properties than the pure hydroxyapatite nanoparticles.

Since no toxic or expensive materials were used in the production of this nanocomposite, it can be expressed that the reduction in costs and environmental pollutions are among the most important advantages of the research. The nanocomposite has been produced through the novel method of freeze drying. This method conserves the porous structure of chitosan in the final product contrary to thermal methods.

In this research, colloid solution containing hydroxyapatite nanoparticles, chitosan and graphene oxide converts into ice in freeze drier device. In this stage, chitosan chains are entrapped in ice crystals. In fact, a consistent network of ice crystals is formed, which is surrounded by chitosan. In the end, the melting of ice crystals in the drying process and their elimination from the networked formed by chitosan creates a very porous scaffold.

Improving mechanical properties and bioactivity of graphene oxide/hydroxyapatite/chitosan nanocomposite in comparison with pure hydroxyapatite nanoparticles is among the important achievements of the research.

Results of the research have been published in RSC Advances, vol. 4, 2014, pp. 25993-25601.