A novel strategy for encapsulation and controlled release of Schisantherin a employing biofriendly polydopamine microparticles built on biomineralized calcium carbonate crystals

Schisantherin A (SCA) has recently attracted increasing attention because of its promising biological profile. However, poor aqueous solubility and bioavailability have limited the efficacy of SCA in pharmaceutical applications. In this study, novel complex CaCO 3 -based biomineralized microparticles that demonstrate significant potential as carriers for loading and delivering SCA were constructed for the first time by employing gum arabic as the stable template and polydopamine as the functional coating agent. The results show that these composite microparticles have a high SCA loading rate of 15.6 ± 0.4 % and a pH-responsive drug release characteristic under simulated in vitro conditions. Further investigation revealed that the encapsulated forms of SCA exhibit significantly enhanced synergistic antioxidant activity and antibacterial efficacy against Staphylococcus aureus compared to the carrier-free SCA. Furthermore, a 4′,6-diamidino-2-phenylindole (DAPI) staining experiment and a rhodamine 123 (Rh123) fluorescence staining test of lipopolysaccharide (PSL) induced BV-2 microglial cells demonstrated that the encapsulated form of SCA exhibits considerable efficacy in inducing changes in the morphology and structure of cells. With these findings, this study provides a new type of CaCO 3 -mediated particle carrier that is useful for targeted and controlled release applications.