Rationally modified-CaCO₃ carriers for prolonged drug release and radionuclide retention in combination chemo-radionuclide therapy

Importantly, the incorporation of 2AT and radiolabeling with ²²³Ra resulted in a slower dissolution of the CaCO₃ microparticles compared with the unloaded carrier. The resulting changes in carrier dissolution contribute to prolonged retention of the therapeutic components and provide sustained local exposure following intratumoral administration.

The developed microparticles were comprehensively characterized, and their stability and release behavior were evaluated under different pH conditions. Their interaction with B16-F10 cells was investigated <i>in vitro</i>, while biodistribution, antitumor efficacy, and biosafety were evaluated in a murine solid tumor model. This study demonstrates the potential of controlling the physicochemical behavior of a CaCO₃ carrier through incorporation of chemically distinct therapeutic components to achieve prolonged local co-delivery of a chemotherapeutic agent and ²²³Ra.</p>