Polymer assisted isolation of hydroxyapatite from Thunnus obesus bone

The combination of micro and nanostructured hydroxyapatite (HAp) was isolated from Thunnus obesus bone via thermal calcination method in the presence of polymers such as poly ethylene glycol (PEG), poly (ethylene glycol)-block-poly (propylene glycol)-block-poly (ethylene glycol) (PEG-PPG-PEG) and poly vinyl alcohol (PVA). The thermal stability, crystalline phase, chemical composition and morphology of the derived HAp were characterized by thermal gravimetric analysis, X-ray diffraction analysis, Fourier transform infrared spectroscopy and field emission scanning electron microscopy analysis. The physicochemical characteristic examination revealed that derived HAp was coherent with standard HAp data. Moreover, FE-SEM depicted significant difference in the crystal size of HAp derived with thermal calcination, with and without added polymers. The crystallinity of HAp isolated in the presence of polymer was lower than that obtained in the absence of polymers. The biocompatibility of the derived HAp crystals was checked with MC3T3-E1 osteoblastic cells by MTT assay and Hoechst-33342 staining. The biocompatibility of HAp derived by polymer assisted thermal calcination method revealed that it is less toxic as compared to HAp derived in the absence of polymer. As an inference, polymer assisted thermal calcination derived HAp is good in terms of the presence of combined micro and nanostructured HAp and its low toxicity will bring about new orthopaedic applications.