Correction to: Nature Reviews Materials https://doi.org/10.1038/s41578-021-00358-0, published online 10 August 2021.

The definition of DDAB was corrected to dimethyldioctadecylammonium bromide. In addition, the structure of PEG2000-DMG has been corrected in Figure 2, and its definition in the Figure 2 caption and in the main text has been corrected to 1,2-dimyristoyl-rac-glycero-3-methoxypolyethylene glycol-2000. The definition of PEG2000-DSG has been corrected to 1,2-distearoyl-rac-glycero-3-methoxypolyethylene glycol-2000. These have been corrected both in the PDF and in the HTML versions of the article.