LAUSR

Safe and efficient production of chimeric antigen receptor (CAR)‐T cells is of crucial importance for cell‐based cancer immunotherapy. Physical transfection methods have quickly gained in importance in the context of transfecting T‐cells, since they are readily compatible with different cell types and a broad variety of cargo molecules. In particular, nanoparticle‐sensitized photoporation has been introduced in recent years as a gentle yet efficient method to transiently permeabilize cells, allowing subsequent entry of external cargo molecules into the cells. Gold nanoparticles (AuNPs) have been used the most as photothermal sensitizers because they can easily form laser‐induced vapor nanobubbles, a photothermal phenomenon that is shown to be particularly efficient for permeabilizing cells. However, as AuNPs are not biodegradable, clinical translation is hampered. Here, for the first time, the possibility to form laser‐induced vapor nanobubbles from biocompatible polymeric nanoparticles is reported. Compared to electroporation, the most used physical transfection method for T cells, 2.5 times more living mRNA transfected human T cells are obtained via photoporation sensitized by polydopamine nanoparticles. This shows that photoporation is a viable approach for efficiently producing therapeutic engineered T‐cells at a throughput easily exceeding 105 cells per second.