Skin-Adaptive Hydrogel Patch with Antitumor Activity for Tumor Elimination

Postoperative residual tumor cells and their oxidative stress-induced injury to normal skin cells often cause tumor recurrence. Hence, doxorubicin-loaded mesoporous silica (SiO₂@DOX) nanoparticles were incorporated into polydopamine-polyacrylamide (PDA–PAM) hydrogel through hydrogen bond interaction to obtain a hydrogel patch (SiO₂@DOX/PDA–PAM). The covalent and noncovalent cross-linked SiO₂@DOX/PDA–PAM hydrogel exhibits flexible mechanical properties (toughness of 7.38 kJ/m³, compressive strength of 62.28 kPa) and strong adhesion properties (adhesive strength of 8.04 kPa). The porous structures of SiO₂@DOX greatly increased the DOX loading ability, and those were uniformly dispersed in the hydrogel. In vitro DOX release of the SiO₂@DOX/PDA–PAM hydrogel avoided DOX burst release and realized slow release in a sustained manner (about 84.74% at 120 h), resulting in excellent in vitro antitumor efficacy (92.84%) after 48 h treatment. Besides, the hydrogel also protected normal cells from oxidative damage by scavenging massive reactive oxygen species (ROS). Therefore, the hydrogel patch holds great promise in elimination of postoperative residual tumor.