Photothermal and photodynamic responses of core-shell Mo₂C@C@Fucoidan nanospheres

Mo₂C structure, a transition metal carbide, is known for its exceptional properties including high chemical and thermal stability and surface activity. Recently, carbon-modified Mo₂C structures have found widespread applications due to their effectiveness. Here, we synthesized pomegranate-like Mo₂C@C nanospheres and coated them with poly(allylamine hydrochloride) (PAH) and fucoidan structures. Characterization techniques including FE-SEM, HR-TEM, XRD, XPS, and zeta potential analysis were employed. We investigated the effect of Mo2C@C@Fuc nanospheres by quantitatively evaluating their photothermal conversion efficiency. Under irradiation at wavelengths of 808 nm and 1064 nm with a power intensity of 2 W/cm², these nanospheres could convert up to 15 % of the incident laser energy into heat, outperforming conventional materials. Stability tests in various physiological pH environments confirmed their durability under NIR irradiation, ensuring operational integrity in biological environments. In addition, they showed significant efficiency in the production of singlet oxygen, making them promising agents for PDT. Biodegradation studies indicated safe degradation after therapeutic application, highlighting their environmental and physiological compatibility. Integrating Mo₂C@C@Fuc nanospheres into anticancer strategies combines the advantages of PTT and PDT, promising improved therapeutic outcomes with high biocompatibility.