A Self-Reporting Mineralized Conductive Hydrogel Sensor with Cancer-Selective Viscosity, Adhesiveness, and Stretchability

A cancer-selective self-reporting sensor based on a redox-responsive mineralized conductive hydrogel (M-Hydrogel) is proposed with cancer-specific viscosity, adhesive strength, stretchability, tunable conductivity, and fluorescence. The redox-triggered release of carbonized polydopamine (cPDA) from the loaded disulfide-crosslinked polymer dots (PD@cPDA) in the hydrogel matrix modulates the macroporous structure responsible for self-recognizable cancer sensing and photothermal activity for cancer therapy. The self-reporting nature of the M-Hydrogel sensor is highlighted when in vicinity of a high glutathione (GSH) level owing to the controllable pore size and H-bonding by cPDA, as confirmed by experiments on cancer cells (HeLa, PC3, B16-F10-GFP, and SNU-C2A) and normal cells (CHO-K1). The lower viscosity during syringe test along with the exceptional adhesiveness and stretchability with various cancer cells, combined with a high wireless pressure-sensing response absent in normal conditions, confirms the dependence of self-recognizable behavior on the cancer microenvironment. The M-Hydrogel demonstrates excellent ex situ sensing with tumor ablation, after implantation in mice xenografted with HeLa cells, with the wireless sensing system, enabling real-time analysis coupled with the upregulation of pro-apoptotic markers P53 and BAX in the tumor. Therefore, this self-reporting sensor may facilitate a strategy for innovative and convenient cancer diagnostics.