Metastable FeSe2 nanosheets as a one-for-all platform for stepwise synergistic tumor therapy.

The urgent need to curb the rampant rise in cancer has impelled the rapid development of nanomedicine. Under the above issue, transition metal compounds have received special attention considering their physicochemical and biochemical properties. However, how to take full advantage of the valuable characteristics of nanomaterials based on their spatial structures and chemical components for synergistic tumor therapy is a worthwhile exploration. In this work, a tailored two-dimensional (2D) FeSe2 nanosheet (NS) platform is proposed, which integrates enzyme activity and drug efficacy through the regulation of itsstability. Specifically, metastable FeSe2 NSs can serve as dual nanozymes in an intact state, depleting GSH and increasing ROS to induce oxidative stress in the tumor microenvironment (TME). With the gradual degradation of the FeSe2 in TME, its degraded products can amplify the Fenton reaction and GSH consumption, enhance the expression of inflammatory factors, and achieve effective near-infrared (NIR)-light irradiation-enhanced synergistic photothermal therapy (PTT) and chemodynamic therapy (CDT). Our exploration further confirmed such a strategy that may integrate carrier activity and drug action into a metastable nanoplatform for tumor synergistic therapy. These results prompt the consideration of the rational design of a one-for-all carrier that can exhibit multifunctional properties and nanomedicine efficacy for versatile therapeutic applications in the future.

Introducing Specific Iodine Ions in Perovskite-Based Nanocomplex to Cater for Versatile Biomedical Imaging and Tumor Radiotherapy.

Multimodal biomedical imaging and imaging-guided therapy have garnered extensive attention owing to the aid of nanoagents with the aim of further improving the therapeutic efficacy of diseases. The ability to engineer nanocomplexes (NCs) or control how they behave within an organism remains largely elusive. Here, a multifunctional nanoplatform is developed based on stabilized I-doped perovskite, CsPbBr3 -x Ix @SiO2 @Lip-c(RGD)2 (PSL-c(RGD)2 ) NCs. In particular, by regulating the amount of regular I- ions introduced, the fluorescence emission spectrum of perovskite-based NCs can be modulated well to match the requirement for biomedical optical imaging at the scale from molecule, cell to mouse; doping 125 I enables the nanoformulation to be competent for single-photon emission computed tomography (SPECT) imaging; the introduction of 131 I- imparts the NCs with the capability for radiotherapy. Through facile manipulation of specific iodine ions, this nanoplatform exhibits a remarkable ability to match multifunctional biomedical imaging and tumor therapy. In addition, their in vivo behavior can be manipulated by adjusting the thickness of the silica shell and the surface polarity for more practical applications. These experimental explorations offer a novel approach for engineering desirable multimodal NCs to simultaneously image and combat malignant tumors.

A small pore black TiO2/-large pore Fe3O4 cascade nanoreactor for chemodynamic/photothermal synergetic tumour therapy.

Various unique spatial structures are often found in the enzymes of biological systems. From the consideration of bionics, it is challenging but meaningful to design nanozymes with distinctive structures to enhance their bioactivities. To explore the relationship between the structure and activity of nanozymes, in this work, a special structural nanoreactor, namely small pore black TiO2 coated/doped large pore Fe3O4 (TiO2/-Fe3O4) loaded with lactate oxidase (LOD), was constructed for chemodynamic and photothermal synergistic therapy. Specifically, LOD loaded on the surface of the TiO2/-Fe3O4 nanozyme alleviates the low level of H2O2 in the tumour microenvironment (TME); the black TiO2 shell with multiple pinhole channels and a large specific surface area not only facilitates LOD loading, but also enhances the affinity of the nanozyme for H2O2; H2O2 is continuously enriched on the surface of the TiO2/-Fe3O4 nanozyme and transmitted to mesoporous Fe3O4, in turn efficiently producing abundant toxic hydroxyl radicals (˙OH) for chemodynamic therapy. Meanwhile, the TiO2/-Fe3O4 nanozyme under 1120 nm laser irradiation has excellent photothermal conversion efficiency (η = 41.9%), and further accelerates the production of ˙OH for amplifying the chemodynamic therapy efficiency. This self-cascading, special structure nanozyme provides a novel strategy for application in highly efficient tumour synergetic therapy.