A. Ben-Yakar

Organiser's Note: The presenter of this talk withheld their permission for video to be published.

The application of femtosecond (fs) lasers to biomedicine opens new opportunities for the study of biological systems and the diagnosis and treatment of diseases. The ultra high peak intensities of fs-lasers enable nonlinear interactions between light and tissue. These nonlinear interactions confine energy absorption to focal volumes beneath the surface enabling precise ablation (surgery) inside the tissue as well as three-dimensional imaging with high resolutions.

I will first present an elegant application of fs-laser nanosurgery performed in vivo in a model organism, C. elegans to study nerve regeneration [1]. The high precision of ablation allows inducing controlled injury of axons inside the nematode and studying the regeneration process of severed axons in vivo. By developing a high-throughput laser nanoaxotomy platform using integrated microfluidic devices [2], we can now pursue rapid identification of genes and molecules that affect nerve regeneration. Next, I will discuss how we combine the focusing power of plasmonic nanoparticles to provide nano-scale ablation [3] and how we take advantage of bright two-photon luminescence of plasmonic gold nanorods to develop bright contrast agents for molecular imaging of cancer cells [4]. When integrated into our new miniaturized probe for laser microsurgery with two-photon imaging capabilities [5], these plasmonic tools will help us in the realization of an advanced "seek-and-treat" probe to aid in the early diagnosis and therapy of cancer.

We are witnessing the beginning of a new exciting field. Shaping these ultrafast laser assisted technologies with creative engineering ideas and unique plasmonic tolls will allow promising breakthroughs in biology and medicine.

[1]Yanik F, Cinar H, Cinar N, Chisholm A, Jin Y, and Ben-Yakar A, "Neurosurgery: Functional regeneration after laser axotomy." Nature 432, 882 (2004).

[2]Guo X, Bourgeois F, Chokshi T, Durr N, Hilliard M, Chronis N, and Ben-Yakar A, "Femtosecond laser nanoaxotomy lab-on-a-chip for in vivo nerve regeneration studies", Nature Methods 5(6), 531 (2008).

[3]Eversole D, Luk'yanchuk B, and Ben-Yakar A, "Plasmonic Laser Nanoablation of Silicon by the Scattering of Ultrafast Pulses near Gold Nanospheres." Invited, Appl. Phys. A, 89, 283-291 (2007).

[4]Durr NJ, Larson T, Smith DK, Korgel BA, Sokolov K, and Ben-Yakar A, "Two-photon luminescence imaging of cancer cells using molecularly targeted gold nanorods", Nano Lett., 7 (4), 941-945 (2007).

[5]Hoy CL, Durr NJ, Chen P, Piyawattanametha W, Ra H, Solgaard O, and Ben-Yakar A, "Miniaturized probe for femtosecond laser microsurgery and two-photon imaging", Opt. Exp., 16 (13), 9996 (2008).

Keywords (Optional): 
laser nanosurgery
nerve regeneration
C. elegans