Weak acidity (6.5-6.9) and limited H2O2 level in the tumor microenvironment (TME) usually impact the therapeutic effect of chemodynamic therapy (CDT) for cancer. A Specific TME promotes the formation of an immunosuppressive microenvironment and results in high rate of recurrence and metastasis of cancer. Fe3O4@ZIF-8/GOx@MnO2 multi-layer core shell nanostructure was constructed as a hybrid nanozyme. After magnetic targeting of the tumor site, the outermost MnO2 shell catalyzed H2O2 in TME to produce O2 and was broken due to the reaction with glutathione. Due to the acid response, the ZIF-8 layer would crack and release glucose oxidase (GOx) and Fe3O4. The generated O2 was utilized by GOx in starvation therapy to consume glucose and produce H2O2 and gluconic acid. The Fenton reaction efficiency of Fe(II) was improved by the increased H2O2 concentration and the enhanced acidity in TME. At the same time, the intrinsic photothermal effect of Fe3O4 upon 808 nm laser irradiation promoted the activity of MnO2 and GOx as oxidase, and Fe(II) as catalase-like, and ablated the primary tumor. Moreover, the hybrid nanozyme can facilitate the transformation of M2-type macrophages to M1-type, and strong systemic antitumor immune effect was induced. A synergy of multiple therapeutic modes including starvation therapy, CDT, photothermal therapy (PTT), and immunotherapy can be realized in the hybrid nanozyme for tumor therapy.

A multimodal strategy of Fe3O4@ZIF-8/GOx@MnO2 hybrid nanozyme via TME modulation for tumor therapy

Sulfur-Regulated Defect Engineering for Enhanced Ultrasonic Piezocatalytic Therapy of Bacteria-Infected Bone Defects

Nanomedicine potentiates mild photothermal therapy for tumor ablation

Reactive oxygen species (ROS) has been employed as a powerful therapeutic agent for eradicating tumor via oxidative stress. As an emerging ROS-involving noninvasive anticancer therapeutic modality, sonodynamic therapy (SDT) with high tissue penetration depth and benign remote spatiotemporal selectivity has been progressively utilized as the distinct alternative for ROS-based tumor treatment. However, the hypoxic tumor microenvironment substantially restricts the sonodynamic effect. In this work, an oxygen self-sufficient hybrid sonosensitizer on the basis of photosynthetic microorganisms cyanobacteria (Cyan) integrated with ultrasmall oxygen-deficient bimetallic oxide Mn1.4 WOx nanosonosensitizers, termed as M@C, is designed and engineered to overcome the critical issue of hypoxia-induced tumor resistance and strengthen the SDT effect. The sustained photosynthetic oxygen production by Cyan under light illumination can promote Mn1.4 WOx nanosonosensitizers to produce more ROS against cancer cells both in vitro and in vivo under ultrasound (US) irradiation. Especially, the sustained oxygen evolution for suppressing the gene expression of hypoxia-inducible factor 1alpha (HIF-1α) further boosts and augments the SDT efficiency. Thus, this work provides the paradigm that the rationally engineered biohybrid microorganism-based multifunctional sonosensitizers can serve as an effective bioplatform for augmenting the therapeutic efficiency of SDT, particularly for the treatment of hypoxic tumors. This article is protected by copyright. All rights reserved.

Huizhong Xu

Papers

Liquid exfoliation of TiN nanodots as novel sonosensitizers for photothermal-enhanced sonodynamic therapy against cancer