Infrared Light Activated Highly Efficient Cell Therapy Using Flower-Shaped Microstructure Device

In this pioneering study, an infrared light-activated highly efficient and uniform, small to large biomolecular delivery into various cell types is developed using a flower-shaped microstructure device (FMD). Featuring a unique structural design, this FMD consists of 8 µm in length, with edges of ≈3 and 20 µm gaps between FMD microstructure. When subjected to IR laser exposure at 1050 nm, the FMD triggers the generation of photothermal cavitation bubbles, exerting jet fluid flow on the cell's plasma membrane surface, and facilitating biomolecule delivery into cells. The platform achieves efficient intracellular delivery spanning various biomolecules — from low-molecular-weight propidium iodide dye to higher molecular weight siRNA, plasmid, and enzymes — across human cervical (SiHa), mouse fibroblast (L929), and neural crest-derived (N2a) cancer cells, ensuring consistently high efficiency without compromising cell viability. 95% delivery efficacy and 96% cell viability are achieved for smaller molecules like PI dye in L929 cells. For larger biomolecules such as enzymes, transfection efficiency reached 82%, and cell viability is nearly 90% in SiHa cells. This is confirmed via confocal microscopy and flow cytometry, the FMD-based delivery system holds broad potential for cellular diagnostics and therapeutics, promising significant advancements in cellular research and biomedical treatments.