Abstract
Non-melanoma skin cancer (NMSC) is one of the most common types of cancer worldwide. Despite the low mortality rate, rising incidence and recurrence rates are a burden on healthcare systems. Standard treatments such as chemotherapy, radiotherapy, and surgery are either invasive or toxic to healthy tissues; therefore, new, alternative, selective treatments are needed. In this work, a combined photothermal and chemotherapeutic approach is proposed. MoS2 was used as photothermal agent. It was prepared by a liquid-phase exfoliation and intercalation method using polyvinylpyrrolidone (PVP), followed by recirculation through a custom-built high-power ultrasonication probe. After 6 h of ultrasonication treatment, the average particle size was 165 ± 170 nm. Near-infrared (NIR) irradiation assays (810 nm, 0.1 W/cm2, 30 min, 180 J/cm2) confirmed that MoS2 nanosheets can efficiently convert NIR light into heat and reach 52 °C. The therapeutic doses of MoS2 (125 µg/mL) and Tegafur (50 µg/mL) were optimized and both were simultaneously incorporated into a Carbopol hydrogel. The cells were brought into contact with the hydrogel and irradiated with a custom-built NIR LED system. In HFF-1 cells (normal human fibroblasts), the metabolic activity was 78% (above the 70% toxicity limit-ISO 10993-5:2009(E)), while in A-431 skin cancer cells, it was 28%. In addition, the MoS2 + Tegafur hydrogels led to a 1.9-fold decrease in A-431 cancer cell metabolic activity, 72 h after irradiation, in comparison to MoS2 hydrogels, indicating a combined effect of photothermal and chemotherapy.