Porous biphasic calcium phosphate scaffolds from cuttlefish bone

Cuttlefish bone is an inexpensive, readily available, morphologically complex natural material. It has an open structure, consisting of layers separated by pillar-like structures made of calcium carbonate. In this study natural bones from cuttlefish were successfully converted into porous biphasic calcium phosphate (BCP) scaffolds with a range of hydroxyapatite and β-tricalcium phosphate compositions. The process involved reaction with solutions of phosphoric acid (H₃PO₄) and 2-propanol, followed by heat treatment at high temperatures (up to 1300°C) in air. The crystalline composition of the BCP scaffolds could be controlled by varying the concentration of the H₃PO₄ in solution, and the duration of reaction time at room temperature. The original microstructure of the cuttlefish bone was preserved in the BCP scaffolds which featured >90% interconnected porosity. The structure consisted of continuous macroporous channels with smallest measured cross-sectional openings of 400 νm × 100 νm size. The BCP scaffolds prepared with 16 wt% H₃PO ₄ solution had a measured compressive strength of 2.38 ± 0.24 MPa, with a characteristic noncatastrophic failure behavior. The ability to tailor the composition of these BCP scaffolds allows development of implants with controlled biodegradation, while their superior mechanical and microstructural properties stand to benefit efficient osteointegration and osteoinduction.