Chemoradiotherapy of ME-180 Tumors with an Intratumoral Cisplatin/Calcium Phosphate Drug Delivery System

Drug delivery systems are able to concentrate cancer drugs in a localized region, thereby increasing drug effectiveness. Side effects are decreased due to reduced systemic drug exposure. This in vivo study investigates the use of a calcium phosphate (CaP) crystal drug delivery system to deliver cisplatin (CDDP) into murine ME-180 tumors. Forty-two athymic Ner-nu/nu mice were put into six groups: untreated control, systemic CDDP, and the CDDP/CaP drug delivery system with, and without, an 8Gy radiation dose. The CDDP/CaP was injected via a 25 gauge needle directly into the intradermal tumor. Tumors were measured daily as well as mouse weight. Data was recorded for 26 days. At the end of 26
^th
day mice were sacrificed and the tumors removed for further studies. Analysis showed the CDDP/CaP drug delivery system was significantly more effective against tumor growth when used alone or with radiation as compared to systemically delivered CDDP alone or with radiaton. Tumors treated with the CDDP/CaP drug delivery system were smaller in volume, or had completed regressed, when compared to the rest of the groups. Also, the CDDP/CaP groups exhibited less weight loss, an indication of reduced systemic toxicity.