Light-triggered drug release via fiber optic heater-integrated with thermoresponsive microgels for locoregional cancer therapy

: Cancer treatment faces significant challenges due to the nonspecific delivery of chemotherapeutic drugs, resulting in systemic toxicity and limited efficacy. Targeted, localized drug delivery systems offer a transformative approach to overcome these limitations by improving therapeutic precision and minimizing side effects. Here, we propose the development of a novel light-to-heat triggered drug delivery (FO-LTDR) platform by integrating a fiber optic heater (FOH) with doxorubicin-loaded thermoresponsive microgels (DOX@MGs) for the locoregional treatment of cancer. The DOX@MGs, developed using a N-isopropylmethacrylamide-maleic acid formulation, exhibit superior drug loading capacity and controlled release properties, that ensure stability under physiological conditions and selective activation under external thermal stimuli. The FOH is engineered with a core-offset fusion splice and a gold-coated region that enables efficient conversion of optical to thermal energy. The thermal response of the platform is monitored in real time via an integrated fiber Bragg grating. The heat generated by the fiber results in a "squeezing effect" of the microgels covalently bound to its surface, releasing pure doxorubicin in a controlled manner strictly at the site of interest. The FO-LTDR platform demonstrated precise, on-demand drug delivery in 2D/3D MCF7 models, providing a versatile and controllable approach that could transform future strategies for localized chemotherapy.