BACKGROUND:  Single-cell surgery is a powerful and versatile technique that has drastically increased our understanding of biology at the level of an individual cell. With this technique, microinjection, microextraction, and intracellular manipulations can be performed. However, there are limitations with conventional techniques. Conventional glass micropipette techniques introduce enormous mechanical and biochemical stresses on cells, which often results in cell lysis or cell death and low rates of success, especially if performed on mechanically fragile cells. Consequently, there is a need for a less invasive, alternative approach to conventional techniques of single cell surgery.

INNOVATION:  UCLA researchers have developed a novel single-cell surgery tool to perform microinjection, microextraction, and intracellular manipulations with minimal cell damage. This approach utilizes laser induced heating of nanoparticles coated onto the tip of a micropipette. Upon laser excitation, vapor bubbles of nanometer diameter are created around the nanoparticles. When brought in contact with the surface of a cell, this process generates holes in the cell membrane that are precisely-sized. Since this process takes a few nanoseconds, the rest of the membrane does not have time to respond and remains mechanically undisturbed and undamaged. And since metal nanoparticles have a photothermal effect, this allows the nanoparticles, not the cellular components, to absorb the laser power. This leaves both the cell and genetic contents undamaged.

POTENTIAL APPLICATIONS:  Conduct microinjection, microextraction, and intracellular manipulations on cells.

ADVANTAGES

• Less invasive, with minimal cell damage, than conventional microcapillary puncture
• Can be performed on mechanically fragile cells, such as primary cells
• Minimizes exposure of cytoplasm
• Does not require precise laser focusing; as a result it avoids damage to cellular components

DEVELOPMENT-TO-DATE:  Fabrication of the single-cell surgery device is complete. Hole punching on cell membranes have been demonstrated and proof-of-principle experimental results have been carried out.

Reference: UCLA Case No. 2007-564