Abstract

Targeted delivery of chemotherapeutic agents remains a major objective in molecular pharmaceutics to enhance efficacy while minimizing systemic toxicity. This study presents the formulation of pH-responsive polymeric micelles using poly(ethylene glycol)-b-poly(histidine) copolymers for the encapsulation and controlled release of doxorubicin. The micelles were designed to remain stable in physiological pH and rapidly disassemble in acidic tumor microenvironments, promoting selective drug release. Characterization included particle size analysis, critical micelle concentration, drug loading, and release kinetics. In vitro cytotoxicity and uptake studies were performed in MCF-7 breast cancer cells. The system demonstrated efficient drug delivery, increased intracellular accumulation, and enhanced cytotoxicity under acidic conditions, suggesting its potential for targeted anticancer therapy.