Preparation of Hydroxyapatite with High Surface Area and Dispersity Templated on Calcium Carbonate in Dipeptide Hydrogels

Hydroxyapatite (HAP) is the main inorganic component of human skeletal tissue such as bone, teeth et al. Because of its excellent biocompatibility, biodegradability and mechanical properties, it is widely applied in the field of medicine, particularly in bone repairing and drug release. However, it is difficult to prepare HAP particles with good dispersity in aqueous solution and high surface area. To solve the issue, porous CaCO3 were taken as a template to prepare hydroxyapatite with good dispersity and high surface area assisted by a dipeptide hydrogel system. Experimental data show that the sequence of dipeptide has a great effect on the dispersity of hydroxyapatite particles, and the obtained hydroxyapatite has a same particle size with the template of CaCO3, and can be dispersed in an aqueous solution very well. Meanwhile porous hydroxyapatite particles have a large surface area benefiting the loading of model drugs, and illustrate enhanced cell internalization efficiency and low cytotoxicity, which can be used as a sustained-release drug carrier.