Manganese mineralization-boosted photothermal conversion efficiency of Prussian blue for cancer therapy

Although Prussian blue (PB) has been widely investigated as a biocompatible photothermal agent with significant potential in cancer treatment, its further application is still hindered by low photothermal conversion efficiency (PCE) and poor stability. In this study, a biomimetic mineralization approach is employed to improve properties of PB by binding it with manganese phosphate through manganese ions, resulting in the formation of nanocomposite manganese phosphate mineralized Prussian blue (MnP&PB). Compared to PB alone, MnP&PB can significantly enhance the PCE, increasing it to 44.46%, which is attributed to the manganese-induced redshift absorption and the bandgap narrowing in the near-infrared (NIR) region. Meanwhile, MnP&PB demonstrates a significant increase in temperature compared to that of either MnP or PB alone, further enhancing the inhibition effect against cancer under the NIR irradiation. It is revealed that the incorporation of manganese phosphate into PB via biomimetic mineralization lead to the enhancement of both PCE and therapeutic efficacy, thus presenting a promising alternative approach for the improvement of cancer photothermal therapy.