Invitro Bioactivity and Osteogenic Activity Study of Solid State Synthesized Nano-Hydroxyapatite using Recycled Eggshell Bio-waste

Research on hydroxyapatite is experiencing a remarkable increase during the recent years due to its potential biological and biomedical applications. Herein, we have synthesized nano-hydroxyapatite (HAp) by solid state reaction (SSR), wherein recycled eggshell bio-waste as Ca precursor on processing is reacted with synthetic ammonium dihydrogen orthophosphate to form hydroxyapatite (SSHAp). The solid state synthesis reaction is studied by thermogravimetric analysis. The morphology and crystal structure of SSHAp nanoparticles is characterized and found to be spherical and free of aggregation with average crystallite size similar to 10 nm. The SSHAp nanoparticles show large surface area (9.64 m(2)g(-1)). Furthermore, the invitro bio-activity and osteogenic activity of SSHAp is investigated. The osteogenic activity is evaluated by incubating the SSHAp with hFOB cells. The SSHAp is observed to promote appreciable cell attachment and proliferation unlike in control material. While hFOB cells is found to express higher level of osteocalcin, osteopontin, collagen I, osteonectin, BMP-2 and GAPDH on the SSHAp bone graft. The results show that SSHAp nanoparticles graft is bioactive, nontoxic and osteogenic, and has the potential to promote bone therapy applications. The HAp is synthesized using recycled bio-waste contributing to green chemistry, addressing the environmental concerns of recycle and reuse.