The Influence of Chitosan on Water Absorption and Solubility of Calcium Phosphate Cement

Abstract

Calcium phosphate cements are widely used biomaterials for bone regeneration due to their biological properties, such as biocompatibility, biodegradability, and bioactivity. The presence of chitosan in cement composition influences the resorption rate of the material and its mechanical properties. In the present work, the water absorption and solubility of a tricalcium phosphate bone cement, prepared with and without chitosan addition, was comparatively evaluated. The absorption and solubility properties were monitored for 21 days by immersing the samples in water at room temperature and then weighing them. A morphological analysis of the samples was carried out via scanning electron microscopy (SEM). The absorption dynamics and pore evolution were investigated with low-field nuclear magnetic resonance (NMR) relaxometry. It was demonstrated that the presence of chitosan accelerates the hardening dynamics, reduces water absorption, and influences the solubility and degradation behavior of the cement. It was also observed that, independent of the presence of chitosan, the polymerization process is not completed even after one hour, which influences the solubility process. It was also shown that the presence of chitosan reduces the amount of microcracks and improves the functional properties of the hardened cement.