Nanozyme-Powered Giant Unilamellar Vesicles for Mimicry and Modulation of Intracellular Oxidative Stress

The bottom-up construction of enzyme-based artificial cells is generating increasing interest, but achieving artificial cells for "all artificial modules"remains challenging in synthetic biology. Here, we introduce a fully synthetic cell system by integration of biomimetic nanozymes into giant unilamellar vesicles (GUVs). To mimic native peroxidase for free radical generation by taking advantage of Fenton catalysis reactions, we designed and prepared a de novo artificial nanozyme composed of ferritin heavy-chain scaffold protein and catalytic Fe3O4 nanoparticles as the active center. As two examples in bioapplications, we showed this nanozyme-powered GUV system not only mimics intracellular oxidative stress pathways but also induces tumor cell death by sensing and responding to external chemical signals. Specifically, we recreated intracellular biochemical events, including DNA damage and lipid peroxidation, in the compartmentalized GUVs by taking advantage of nanozyme induction of defined catalytic reactions. Additionally, the GUV system also actively induced DNA double-strand breakage and lipid damage of tumor cells, in response to the high expression of H2O2 within the tumor microenvironment. This concept-of-proof study offers a promising option for defining catalysis in biological systems and gives new insights into the de novo creation of artificial cells in a fully synthetic manner.