Attachable Hydrogel Containing Indocyanine Green for Selective Photothermal Therapy against Melanoma.

Melanoma is the most lethal form of skin cancer because it spreads easily to other tissues, thereby decreasing the efficiency of its treatment via chemo-, radio-, and surgical therapies. We suggest the application of an attachable hydrogel for the treatment of melanoma whereby the size and amount of incorporated indocyanine green (ICG) for photothermal therapy (PTT) can be controlled. An attachable hydrogel (poly(acrylamide-co-diallyldimethylammonium chloride); PAD) that incorporates ICG as a near-infrared (NIR) absorber was fabricated using a biocompatible polymer. The temperature of PAD-ICG increases under 808 nm laser irradiation. The hydrogel protects the ICG against decomposition; consequently, PAD-ICG can be reused for PTT. The attachment of PAD-ICG to an area with melanoma in mice, with irradiation using a NIR laser, successfully eliminated melanoma. Thus, the data suggest that PAD-ICG is a smart material that could be used for selective target therapy against melanoma in humans.