Stimuli-responsive hydrogels for ocular tumor therapy

Ocular tumor therapy remains severely hindered by physiological barriers, notably the blood-ocular barrier, which limits drug penetration and specificity, resulting in suboptimal efficacy and potential systemic toxicity. In this context, stimuli-responsive hydrogels have emerged as versatile platforms that enable smart, controllable drug release in response to internal cues (e.g., pH, enzymatic activity, or redox gradients) or external triggers (e.g., temperature, light, or magnetic fields). By enabling targeted delivery, improved biocompatibility, and tunable spatiotemporal control of cargo release, these hydrogels can maximize therapeutic efficacy while minimizing off-target effects. This review systematically surveys recent advances in the design principles, mechanisms, and applications of stimuli-responsive hydrogels across ocular oncology, with emphasis on chemotherapy, immunotherapy, and combination strategies. Furthermore, we discuss translational challenges, including long-term biocompatibility, inter-patient variability in stimulus profiles, and scalable manufacturing processes. Emerging strategies, such as multi-stimuli-responsive platforms, theranostic designs, and personalized hydrogel systems, are highlighted as avenues to enhance safety and clinical translation. Collectively, the perspectives presented herein aim to guide the development of next-generation hydrogel-based therapies for ocular tumors.