E. coli Membrane Vesicles as a Catalase Carrier for Long-Term Tumor Hypoxia Relief to Enhance Radiotherapy

Abstract

Hypoxia is one of the most important factors that limit the effect of radiotherapy, and the abundant H2O2 in tumor tissues will also aggravate hypoxia-induced radiotherapy resistance. Delivering catalase to decompose H2O2 into oxygen is an effective strategy to relieve tumor hypoxia and radiotherapy resistance. However, low stability limits catalase’s in vivo application, which is one of the most common limitations for almost all proteins’ internal utilization. Here, we develop catalase containing E. coli membrane vesicles (EMs) with excellent protease resistance to relieve tumor hypoxia for a long time. Even treated with 100-fold of protease, EMs showed higher catalase activity than free catalase. After being injected into tumors post 12 h, EMs maintained their hypoxia relief ability while free catalase lost its activity. Our results indicate that EMs might be an excellent catalase delivery for tumor hypoxia relief. Combined with their immune stimulation features, EMs could enhance radiotherapy and induce antitumor immune memory effectively.

Deciphering the catalytic mechanism of superoxide dismutase activity of carbon dot nanozyme

“…Horseradish peroxidase, for example, is frequently utilized in enzyme-based sensing for biomarkers 1 , viruses 2 , and bacteria 3 . Catalase, which catalyzes the decomposition of hydrogen peroxide into water and oxygen, could improve the antitumor efficiencies of radiotherapy 4 , sonodynamic therapy 5 , and photodynamic therapy 6 by relieving the hypoxia of tumor microenvironment. Superoxide dismutase has been used to treat skin inflammations 7 , inflammatory arthritis 8 , lung diseases and pulmonary fibrosis 9 , and diabetic nephropathy 10 , etc.…”

Recent advances in biological membrane-based nanomaterials for cancer therapy

“…Third, parts of biological membranes can induce an immune response or contain an anti-tumor substance, and so contribute to inhibiting the growth of tumor, directly. 90–100,200–210…”

“…Third, parts of biological membranes can induce an immune response or contain an anti-tumor substance, and so contribute to inhibiting the growth of tumor, directly. [90][91][92][93][94][95][96][97][98][99][100][200][201][202][203][204][205][206][207][208][209][210] Although biological membranes have been widely used in tumor treatments, the problems of the biological bionic platform cannot be ignored. First, we should consider how to make the extraction process of biological membranes simpler.…”

Development of nanotechnology-mediated precision radiotherapy for anti-metastasis and radioprotection

“…Cell membrane camouflage, proposed by the Zhang's group, has attracted wide attention and has been gradually developed into a novel strategy for designing biomimetic nanomedicines. [127][128][129] To date, the membranes of cancer cells, 30,[130][131][132][133] erythrocytes, 29,134,135 platelets, 136,137 mesenchymal stem cells, 138 and even E. coli [139][140][141] have been successfully used for the preparation of biomimetic radiosensitizing nanomedicines.…”