The intracellular delivery of functional molecules like proteins, transcription factors, and DNA is vital in cell biology. Traditional transfection methods often struggle with delivering large molecules or require carriers such as viruses and peptides, which can be limiting. A new concept based on electrokinetic pumping through nanocapillaries shows promise but has faced challenges in fabricating and operating nanoscale 3D structures. In this research, a hybrid PDMS/glass microfluidic chip featuring a true 3D nanoinjection structure, called the “nanoinjection system,” has been developed. Fabricated using femtosecond-laser ablation in solid glass, this system successfully delivered red fluorescent protein (RFP) and expressed plasmid DNA in various cell types. This nanoinjection system offers controllable molecule delivery and systematic cell separation, improving the purity of processed cells. The cells remained healthy post-injection, suggesting that injection times can be extended to enhance delivery efficiency without compromising cell viability. The carrier-free, dose-controllable, and efficient nanoinjection system is expected to significantly advance cell biology and therapeutics research. -Scientific Journal cover design by scapiens

https://pubs.rsc.org/en/content/articlelanding/2019/lc/c8lc00709h#!divAbstract