Morphology-tailored polydopamine@PtMn nanomaterials for laser-assisted tumor therapy

Laser-assisted tumor therapy can be complemented by redox-active nanomaterials, but the influence of carrier morphology on metal loading and light-to-heat conversion remains insufficiently understood. Herein, spherical PDA@PtMn and hollow FPDA@PtMn nanocomposites were constructed to evaluate how nanoscale PDA morphology regulates PtMn loading, interfacial structure, photothermal conversion, and laser-assisted antitumor activity. Compared with spherical PDA, hollow FPDA possessed a higher specific surface area and more accessible binding sites, resulting in increased Pt/Mn loading and improved exposure of PtMn components. Consequently, FPDA@PtMn displayed enhanced H₂O₂/TMB oxidation response, a larger GSH-related optical response, and higher photothermal conversion efficiency under 808 nm laser irradiation. Cellular experiments further confirmed that FPDA@PtMn promoted nanomaterial uptake and laser-assisted 4T1 cell killing. In 4T1 tumor-bearing mice, FPDA@PtMn with 808 nm irradiation effectively inhibited tumor growth without obvious pathological damage in major organs. These results indicate that nanoscale morphology engineering of PDA-based carriers can regulate PtMn loading, accessible interfacial characteristics, photothermal behavior, and laser-assisted antitumor performance.