Albumin/sulfonamide stabilized iron porphyrin metal organic framework nanocomposites: targeting tumor hypoxia by carbonic anhydrase IX inhibition and T₁–T₂ dual mode MRI guided photodynamic/photothermal therapy

Exploring a nanotheranostic agent with image guided highly efficient therapeutic properties is greatly significant for tumor screening and treatment. Herein, we construct a novel nanoplatform, composed of low cost bovine serum albumin (BSA), sulfonamides (SAs) and iron porphyrin nanoscale metal organic frameworks (NMOFs), which possesses the capability of active targeting to tumor cells and magnetic resonance imaging (MRI) can be used to guide synergetic photodynamic/photothermal therapy. These constructed BSA/SAs–NMOF nanoplatforms can be accumulated more at tumor sites due to modification of the nanoparticles with BSA/SA complexes, allowing this system to achieve long circulation in vivo and to actively target to carbonic anhydrase (CA) IX of tumor cells by the SAs. Moreover, the magnetic iron ion and porphyrin serve as the metal centre and organic ligand of novel NMOFs which exhibit a T₁–T₂ weighted MRI effect (r₁ = 2.7 mM⁻¹ s⁻¹ and r₂ = 19.68 mM⁻¹ s⁻¹) and allow synergetic photodynamic/photothermal therapy of tumors. In vitro reactive oxygen species (ROS) detection and photothermal temperature change results revealed that these BSA/SAs–NMOF nanoplatforms could exhibit a great PDT effect in tumor cells, even under hypoxic conditions, and a remarkable PTT effect with a photothermal conversion efficiency of 40.53%. What's more, there was a greater fatality rate of 4T1 cancer cells in the single wavelength induced PDT & PTT group (95%) than in the PDT or PTT monotherapy groups (nearly 80%), and the growth of a solid tumor was more effectively inhibited by PDT & PTT than by single PTT or PDT. This work provides a novel nanoplatform for targeting tumor hypoxia and achieved highly efficient treatment of tumors based on PDT and PTT.