The influence of structural diversity in polymer-based nanomedicines on anti-cancer efficacy

The structural design of polymeric drug carriers should critically influence the therapeutic performance of nanomedicines by changing their pharmacokinetics. Here, we evaluated four distinct polymer structures of pirarubicin-containing nanomedicines in vivo to determine how differences in inner structure and molar mass affect carrier stability, drug release, and tumor accumulation. Despite comparable drug loading, the carriers showed markedly different anticancer efficacy, with optimized structures achieving superior tumor growth inhibition and improved intratumoral penetration. These results provide direct evidence that polymer structure is a key determinant of treatment outcome and offer guidance for designing more effective polymer-pirarubicin conjugates for anticancer therapy.