Polydopamine‐Modified 2D Iron (II) Immobilized MnPS3 Nanosheets for Multimodal Imaging‐Guided Cancer Synergistic Photothermal‐Chemodynamic Therapy

Abstract Manganese phosphosulphide (MnPS 3 ), a newly emerged and promising member of the 2D metal phosphorus trichalcogenides (MPX 3 ) family, has aroused abundant interest due to its unique physicochemical properties and applications in energy storage and conversion. However, its potential in the field of biomedicine, particularly as a nanotherapeutic platform for cancer therapy, has remained largely unexplored. Herein, a 2D “all‐in‐one” theranostic nanoplatform based on MnPS 3 is designed and applied for imaging‐guided synergistic photothermal‐chemodynamic therapy. (Iron) Fe (II) ions are immobilized on the surface of MnPS 3 nanosheets to facilitate effective chemodynamic therapy (CDT). Upon surface modification with polydopamine (PDA) and polyethylene glycol (PEG), the obtained Fe‐MnPS 3 /PDA‐PEG nanosheets exhibit exceptional photothermal conversion efficiency ( η = 40.7%) and proficient pH/NIR‐responsive Fenton catalytic activity, enabling efficient photothermal therapy (PTT) and CDT. Importantly, such nanoplatform can also serve as an efficient theranostic agent for multimodal imaging, facilitating real‐time monitoring and guidance of the therapeutic process. After fulfilling the therapeutic functions, the Fe‐MnPS 3 /PDA‐PEG nanosheets can be efficiently excreted from the body, alleviating the concerns of long‐term retention and potential toxicity. This work presents an effective, precise, and safe 2D “all‐in‐one” theranostic nanoplatform based on MnPS 3 for high‐efficiency tumor‐specific theranostics.