Self-assembled manganese phthalocyanine nanoparticles with enhanced peroxidase-like activity for anti-tumor therapy

The use of functional nanoparticles as peroxidase-like(POD-like)catalyst has recently become a focus of research in cancer therapy.Phthalocyanine is a macrocyclic conjugated metal ligand,which is expected to achieve a high POD-like catalytic activity,generating free radicals and inhibiting the proliferation of cancer cells.In this paper,we synthesized phthalocyanine nanocrystals with different structures through noncovalent self-assembly confined within micro-emulsion droplets,and manganese phthalocyanine(MnPc)possessing a metal–N–C active center was used as the building block.These nano-assemblies exhibit shape-dependent POD-like catalytic activities,because the emulsifier and MnPc co-mixed assembly reduced the close packing between MnPc molecules and exposed more active sites.The assembly had a water-dispersed nanostructure,which is conducive to accumulation at tumor sites through the enhanced permeability and retention effect(EPR).Because of a highly efficient microenvironmental response,the assembly showed higher catalytic activity only emerged under the acidic tumor-like microenvironment,but caused less damage to normal tissues in biomedical applications.In vivo and in vitro catalytic therapy tests showed excellent anti-tumor effects.This work explored a new way for the application of metal–organic macromolecules such as MnPc as nanozymes for catalytic tumor therapy.

Co-assembly of FeTPP@Fe_(3)O_(4) nanoparticles with photo-enhanced catalytic activity for synergistic tumor therapy

Chemodynamic therapy(CDT)offers a promising alternative to conventional cancer treatment.However,the limited acidity and H_(2)O_(2) concentration in tumor microenvironment(TME)severely impair the anticancer effects of CDT.In this study,we report a microemulsion-assisted coassembly method to prepare iron(III)tetraphenylporphyrin(FeTPP)and magnetic(Fe_(3)O_(4))nanocomposite material(FeTPP@Fe_(3)O_(4)),using photoactive FeTPP and Fe_(3)O_(4) nanocrystals as building blocks.The selfassembling nature of FeTPP results in disordered aggregation and fluorescence quenching,leading to a high light-to-heat conversion efficiency.Continuously,the photo-thermal effect enhances the catalytic decomposition of hydrogen peroxide(H_(2)O_(2))in the Fenton reaction on Fe_(3)O_(4) nanocrystals to generate highly toxic hydroxyl radicals(·OH)to destroy cancer cells.This cascade reaction produces a synergistic therapeutic effect between CDT and photothermal therapy(PTT),which significantly amplifies the therapeutic effect and enhances the treatment outcome of cancer patients.The highly efficient tumor catalytic therapy in vivo results confirmed that this nanomedicine treatment is an excellent biocompatible catalytic nanomedicine therapy achieved through a photo-enhanced Fenton reaction activity approach.