Lentinan in-situ coated tungsten oxide nanorods as a nanotherapeutic agent for low power density photothermal cancer therapy.

Development of high photothermal performance and biocompatible nanotherapeutic agents is of great importance for photothermal cancer treatment. In this paper, we have developed lentinan decorated tungsten oxide nanorods (W₁₈O₄₉@LTN NRs) via a mild one-step solvothermal route. Owing to the numerous surface hydroxyl groups of polymer chains, the presence of lentinan layer in the surface of W₁₈O₄₉ NRs lead to good biocompatibility. The lentinan layer also affects the crystal structure of W₁₈O₄₉ and improves near-infrared absorption (~1.7 × 10⁹ M^-1 cm^-1 at 980 nm), which is two orders of higher than previously reported PEGylated W₁₈O₄₉ nanowires. Even under near-infrared (NIR) laser irradiation at a very low power density of 0.4 W/cm², the temperature of W₁₈O₄₉@LTN NRs aqueous dispersion (125 μg/mL) could increase by 15.1 °C. The photothermal conversion efficiency of W₁₈O₄₉@LTN NRs reaches 33.86%, which is higher than previously reported WO_3-x hierarchical nanostructures (28.1%). Importantly, when cancer cells were treated with W₁₈O₄₉@LTN NRs (200 μg/mL) and 980 nm laser (0.4 W/cm²), a significant photo-induced cell killing behavior was observed. This work demonstrates that W₁₈O₄₉@LTN NRs have the potential for precise cancer treatment.