The role of temperature in forming sol–gel biocomposites containing polydopamine
To further improve the physical strength and biomedical applicability of bioceramics built on hydroxyapatite–gelatin (HAp–Gel) and siloxane sol–gel reactions, we incorporated mussel adhesive inspired polydopamine (PD) into our original composite based on HAp–Gel cross-linked with siloxane. Surprisingly, with the addition of PD, we observed that the processing conditions and temperatures play important roles in the structure and performance of these materials. A systematic study to investigate this temperature dependence behavior discloses that the rate of crosslinking of silane during the sol–gel process is significantly influenced by the temperature, whereas the polymerization of the dopamine only shows minor temperature dependence. With this discovery, we report an innovative thermal process for the design and application of these biocomposites.