Potassium Permanganate

Hindered by the challenges of blood-brain barrier (BBB) hindrance, tumor heterogeneity and immunosuppressive microenvironment, patients with breast cancer brain metastasis have yet to benefit from current clinical treatments, experiencing instead a decline in quality of life due to radiochemotherapy. While virus-mimicking nanosystems (VMN) mimicking viral infection processes show promise in treating peripheral tumors, the inability to modulate the immunosuppressive microenvironment limits the efficacy against brain metastasis. Accordingly, a VMN-based triple immunomodulatory strategy is initially proposed, aiming to activate innate and adaptive immune responses and reverse the immunosuppressive microenvironment. Here, manganese-based virus-mimicking nanomedicine (Vir-HD@HM) with intratumoral drug enrichment is engineered. Vir-HD@HM can induce the immune response through the activation of cGAS-STING by mimicking the in vivo infection process of herpesviruses. Meanwhile, DNAzyme mimicking the genome can rescue the epigenetic silencing of PTEN with the assistance of Mn²⁺, thus ameliorating the immunosuppressive metastatic microenvironment and achieving synergistic sensitizing therapeutic efficacy. In vivo experiments substantiate the efficacy of Vir-HD@HM in recruiting NK cells and CD8⁺ T cells to metastatic foci, inhibiting Treg cells infiltration, and prolonging murine survival without adjunctive radiochemotherapy. This study demonstrates that Vir-HD@HM with triple immunomodulation offers an encouraging therapeutic option for patients with brain metastasis.

Recently, the noble metal Au has been widely applied as the cocatalyst for improving the photocatalytic reduction of CO₂.However, the metallic Au exhibits weak adsorption strength towards CO₂ due to its intrinsic electronic structure with d-orbitals fully filled, thus limiting the activation and reduction of CO₂.To address this issue and maximize the photoreduction of CO₂, herein we designed Au@CZS@MO-400 triple-shelled hollow nanospheres by depositing Cd_0.7Zn_0.3S (CZS) on the outer surface of the MO-400 (MnO₂ annealed at 400 °C) hollow nanospheres and then Au nanoparticles on the CZS surface.It is manifested that the resultant 3%Au@CZS@MO-400 achieves a remarkably boosted photoreduction of CO₂ with the CO/CH₄ yield rates as high as 68.25/12.42 μmol g^-1 h^-1, increased by 3.7/1.5 times over MO-400 and 12.9/1.5 times over CZS.The combined analyses from XPS and d. functional theory calculations confirm the creation of electron-deficient Au^δ+ active sites by modulating their electron configuration by CZS, consequently decreasing the CO₂-Au antibonding-orbital occupancy to reinforce the adsorption strength of CO₂ onto the Au active sites and in turn boost the photoreduction of CO₂.Moreover, it is demonstrated that the Au@CZS@MO-400 hollow nanospheres are quite efficient for supplying the Au cocatalyst with photoelectrons for CO₂ reduction reactions due to the good energy band matching, unique hollow structure and high electron spin polarization of MO-400.This work provides important guidance for understanding and modifying photocatalysts to maximize their photoreduction of CO₂.