Insulin-loaded hydroxyapatite combined with macrophage activity to deliver insulin for diabetes mellitus.

We aimed to develop a diabetes mellitus (DM) treatment that could be administered by intramuscular (IM) injection and it lasted for more than 3 days. The objective was to load insulin into the lattice space of hydroxyapatite (HAP) to prevent its release based on a concentration gradient or detachment from the surface, with insulin release being aided by cellular activity. To avoid insulin denaturation during the synthesis of insulin-loaded HAP (insHAP), we developed a single-step insHAP synthesis method by the hydrolysis of brushite.