Polyethylene glycol–modified molybdenum oxide as NIR photothermal agent and its ablation ability for HeLa cells

Molybdenum oxide, as one of the important transition metal semiconductor materials with photothermal property, has received increasing attention in the field of catalysis, sensing, energy storage, and clinical biomedicine. To improve its certain limitations such as poor biocompatibility and easy agglomeration during application as biomaterials and promote its performance as photothermal agent in biomedical fields, polyethylene glycol (PEG)–modified molybdenum oxide was synthesized and the synthesis conditions during the hydrothermal process, including the pH values and the amount of PEG added, were adjusted. Owing to the reduction function of PEG, as-obtained PEG-MoO _x showed good photostability and colloidal stability, which were beneficial to its application in long-term clinical photothermal therapy. In addition, cell experiments indicated that PEG-MoO _x particles exhibited low cytotoxicity and ability of photothermal killing for HeLa cells. With the increase PEG-MoO _x particles in solution, the photothermal ablation ability of PEG-MoO _x particles for the HeLa cells was enhanced under an 808-nm NIR laser irradiation. Hence, PEG-MoO _x particles have great potential in the photothermal treatment of diseases.