Fluid jets deliver material to individual cells

Physicists at Duke University have developed a way to produce sharp fluid jets with enough precision that they can inject material into a single living cell.

The technique promises a way to selectively deliver drugs to individual cells, which is likely to be very valuable for research involving stem cells and other cellular-level studies.

The physicists produced the jets by focusing lasers into a fluid surrounding a target cell. The lasers heated molecules of a blue dye dissolved in the fluid, which in turn created tiny bubbles to rapidly grow and collapse.

When these sorts of bubbles are produced individually, they create shock waves that spread throughout the liquid. Producing two adjacent bubbles in rapid succession results in small, powerful jets capable of creating holes measuring 0.2 microns in cell membranes.

The researchers confirmed that the jets allowed the introduction of fluids into the cell by checking for signs of the blue dye inside the pierced cells.

The dye is toxic and killed the pierced cells, but the holes the jets produced were small enough that it’s likely that the jets will offer a way to inject live cells with non-toxic substances without significantly damaging them.

The research appears in the current issue of the APS journal Physical Review Letters.