Intracellular delivery of bioactive molecules using light-addressable nanocapsules.

This paper describes a method by which molecules that are impermeable to cells are encapsulated in dye-sensitized lipid nanocapsules for delivery into cells via endocytosis. Once inside the cells, the molecules are released from the lipid nanocapsules into the cytoplasm with a single nanosecond pulse from a laser in the far red (645 nm). We demonstrate this method with the intracellular release of the second messenger IP(3) in CHO-M1 cells and report that calcium responses from the cells changed from a sustained increase to a transient spike when the average number of IP(3) released is decreased below 50 molecules per nanocapsule.