Photo‐Responsive Ovalbumin‐Loaded MnO₂ Nanoparticles for Enhanced T₁‐Magnetic Resonance Imaging and Immunotherapy of Cancer

Abstract Photo‐responsive combinational therapeutics attained significant attention in cancer theranostic owing to the versatile features of nanomaterials. The simplest nano‐design with unique properties to carry out multifunctionalties is a challenging assignment. Herein, a facile solvothermal method is employed to fabricate homogeneous MnO 2 sea urchin‐shaped nanoparticles (MnO 2 ‐OVA NPs) with a high loading capacity (86.15%) of ovalbumin (OVA) antigen. The prepared MnO 2 ‐OVA NPs demonstrated excellent biocompatibility against different cell lines and significant cellular uptake, resulting in mature dendritic cells to enhance anti‐tumor immunity. The synthesized sea urchin‐shaped MnO 2 ‐OVA NPs further exhibited self‐generated catalytic properties that efficiently relieve tumor hypoxia and improve cancer therapies. More excitingly, MnO 2 ‐OVA NPs endorsed reactive oxygen species (ROS) in response of minute UV irradiation (mW) for photodynamic therapy. Further, the prepared photo‐responsive nanoparticles showed promising T 1 ‐MR imaging and relaxivity properties for diagnosis and real‐time drug delivery monitoring. These synergetic therapeutic strategies produced by MnO 2 ‐OVA NPs showed excellency as a potential theranostic agent.