Edmonton, Alberta, Canada--At the Ultrafast Optics and Nanophotonics Laboratory, University of Alberta, engineers are collaborating with cell and developmental biologists to demonstrate the use of femtosecond laser pulses to introduce, remove, and modify molecules and cellular material within the cellular environment.

Tools that enable non-invasive manipulation of living biological systems have multiple applications in biomedical research. Microinjection and electroporation, currently the prevalent techniques, remain in some measure invasive and, while invaluable, are subject to significant limitations. For microinjection, the injection tip must perforate several cell layers for exogenous delivery into, or extraction from, deep-lying cells. In electroporation, a proper balance between pulse number and duration, voltage and waveform must be established in order to avoid irreparable damage and disruption of biochemical pathways. To date, targeting key developmental features within multicompartmental biological systems remains a challenge.

Recently, Vikram Kohli and Abdulhakem Elezzabi demonstrated nanosurgery on living embryonic cells (see Figure). Using zebrafish as their animal model system, femtosecond laser pulses were used to transiently permeabilize blastomere cells for delivery of exogenous material, including fluorescent probes, quantum dots, and plasmid DNA. Surrounding the developing embryo is a non-cellular layer, known as the chorion, which protects the embryo from the environment. Femtosecond laser pulses were focused beyond the chorion onto the embryonic cells.

Kohli presented these findings in three papers at the Photonics West conference in January. For a full review of this work, see the original article by Kohli and Elezzabi at SPIE Newsroom.

Thu Jan 31 20:09:00 CST 2008