Output: Mazur and Ingber (Harvard Medical School) are studying photodisruption in cells with sub-cellular precision. The photodisruption is achieved by focusing nanojoule, femtosecond laser pulses with high numerical-aperture microscope objectives. The figure shows the central slice of a photodisrupted cell. The size of cuts through the top half of the cell, made with energy ranging from 2 nJ to 0.5 nJ is comparable to the width of a single actin fiber bundle. In the lower half of the cell, holes were punched using 100 to 500 pulses. The side view of a cell cut with 2 nJ, 100 fs laser pulses is also shown. Tissue is removed only from the middle of the cell leaving both the top and bottom layers intact.
Outcome: Our new technique allows us to photodisrupt biological tissue with great precision, with potential applications in laser microsurgery. The very small amount of energy and near-infrared wavelength used to photodisrupt sub-cellular structures makes it possible to apply this procedure to living cells for cellular structure and function research, such as the analysis of cytoskeleton integrity in living cells.