SYNTHESIS, PROPERTIES, AND INTRATUMORAL EVALUATION OF MITOXANTRONE-LOADED CASEIN MICROSPHERES IN LEWIS LUNG-CARCINOMA

Smooth, round, uniform bovine casein microspheres of 1-5 and 10-20 mum size were readily prepared by a steric stabilization technique previo usly developed in this laboratory for synthesis of albumin microsphere s. The avid phagocytic uptake of casein and albumin microspheres was d emonstrated with fluorescein-labelled microspheres using a macrophage- like mouse myelomonocytic leukaemia cell line. Post-synthesis loading of 25% mitoxantrone was achieved for casein microspheres containing 20 % polyglutamic acid. Preliminary intratumoural chemotherapy experiment s with a mouse Lewis lung carcinoma indicated that mitoxantrone and mi toxantrone-loaded casein-polyglutamic acid microspheres exhibited lowe r toxicity when administered intratumorally.