The extraction and characterization of porous HA/β-TCP biphasic calcium phosphate from sole fish bones at different temperatures

Nowadays, BCPs are recognized as the gold standard of bone substitutes in bone reconstructive surgery. Studies have shown that BCP derived from some marine fishbones have the advantages of simple preparation method, low calcination temperature, natural micro-pore structure and high β-TCP content. Therefore, the purpose of this study is to extract BCP from a marine fish bone (sole fish) and to research the characteristics of the composition and microstructure. We calcined the sole fish bones at 700 °C to 1100 °C, and then x-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), inductively coupled plasma optical atom emissions spectroscopy (ICP-OES), scanning electron microscopy (SEM) and mercury intrusion porosimeter (MIP) were used to characterize the composition and microstructure of calcined material. The results showed that BCP material was observed above 800 °C, with abundant macropores and micropores, crystalline grain size at nanometer level and high porosity. The relative content of β-TCP was increased with the rise of temperature at 700 °C to 1000 °C, to the highest at 1000 °C. With the rise of temperature, the crystalline grain size and micropore size were gradually increased, and the specific surface area was gradually decreased, while there was no significant change in the macropore size. The porosity showed no significant change below 800 °C, significantly increased at 800 °C to 900 °C and gradually decreased above 900 °C. These results suggest that the sole fish bone can be calcined at a relatively lower temperature to extract BCP material with a large amount of β-TCP and a good micro-pore structure. Sole fish bone will be potentially used as a bioceramic bone alternative scaffold in the clinical practice in the future.