Hydrogels for Local Treatment of Cutaneous Malignancies: Preclinical Progress and Translational Prospects

Cutaneous malignancies, including malignant melanoma and nonmelanoma skin cancers, are among the most common cancers worldwide and are currently treated with surgical excision as first‐line therapy, while topical therapy also occupies an important position. Hydrogels are crosslinked hydrophilic polymer networks that can undergo in situ gelation on lesions or postoperative wounds, adhere to the skin and provide stimulus‐responsive controlled release of drugs and have been developed as local delivery platforms, including microneedle‐based systems, in preclinical treatment studies of cutaneous malignancies. This narrative review integrates preclinical studies from the past 5 years on hydrogel systems for local treatment of cutaneous malignancies from a dermatology‐oriented translational perspective. Evidence is organised by therapeutic mechanism into light‐mediated, immunomodulatory, antitumour–pro‐repair and microneedle‐delivered hydrogels. Light‐mediated hydrogels combine photothermal or photodynamic components with tunable optical parameters to achieve near‐infrared‐triggered tumour ablation and, in some systems, simultaneous support of wound healing and remodelling. Immunomodulatory hydrogels construct local immune depots that reshape the tumour microenvironment, promote dendritic‐cell maturation, enhance cytotoxic T‐cell responses and regulate tumour‐associated macrophage polarisation. Antitumour–pro‐repair hydrogels coordinate local cytotoxic or metabolic effects with antioxidant, anti‐inflammatory and barrier‐restoring functions to sustain tumour suppression while supporting tissue repair, whereas microneedle‐delivered hydrogels‐coupled microneedle geometry and mechanics with in situ gelling or swelling to improve transdermal access, enable microenvironment sampling and facilitate outpatient application. Across these platforms, priorities include adhesion and resistance to exudate and friction, spatiotemporally controlled release, adequate mechanical strength and insertion performance, modular and couplable architectures, reproducible local dosing and triggering, biocompatibility and stability, integration with surgical and outpatient workflows, and validation within clinical frameworks focused on recurrence control, margin status and functional–cosmetic outcomes.