Ratiometric Strategies in Oncology: Multifunctional Roles in Chemotherapy, Imaging, and Diagnosis.

Cancer remains one of the leading causes of mortality worldwide, necessitating innovative therapeutic strategies that enhance treatment efficacy while minimizing toxicity. Ratiometric codelivery has gained attention as a promising approach to improve the effectiveness of cancer chemotherapy to address the limitations of conventional monotherapies and random drug combinations. By enabling the simultaneous delivery of multiple anticancer drugs in fixed, synergistic ratios, this strategy helps achieve synergistic effects, reduces systemic toxicity, and combats multidrug resistance. The review outlines the scientific rationale behind this approach and the importance of maintaining optimal drug ratios for effective cancer treatment. The emphasis is placed on nanocarrier platforms, such as liposomes, polymeric nanoparticles, dendrimers, and lipid-polymer hybrid nanoparticles, that enable the simultaneous and targeted release of drugs at optimized ratios. The article also examines the synergistic and combinatorial delivery, release kinetics, and in vitro and in vivo therapeutic efficacy of these systems in enhancing treatment outcomes across various cancer types. Furthermore, the technical challenges, clinical studies, and commercial landscape are also highlighted. This review concludes by outlining future directions and the need for translational research to bring ratiometric codelivery systems from bench to bedside.