Nanoparticle mediated laser cell perforation Markus Schomaker, 1,* Judith Baumgart, 1 Anaclet Ngezahayo, 2 Jörn Bullerdiek, 3,4 Ingo Nolte, 3 Hugo Murua Escobar, 3,4 Holger Lubatschowski, 1 and Alexander Heisterkamp 1 1 Laser Zentrum Hannover e.V. and Research Cluster of Excellence „REBIRTH“, Hollerithallee 8, Hannover, Germany 2 Institute of Biophysics, Leibniz University, Herrenhaeuserstr. 2, Hannover, Germany 3 Small Animal Clinic and Research Cluster of Excellence "REBIRTH", University of Veterinary Medicine Hanover, Bischofsholer Damm 15, D 30173 Hanover, Germany 4 Centre for Human Genetics, University of Bremen, Leobener Strasse,ZHG, D-28359 Bremen, Germany *Corresponding author: m.schomaker@lzh.de Abstract: We present our results for nanoparticle mediated laser poration as an alternative transfection technique. As a fundamental part for the perforation of the cell membrane the interactions of gold nanoparticles and living cells were studied. 1. Introduction A key technology in molecular biology is the transfection of DNA/RNA molecules into target cells. Conventional methods to permeabilize the cell membrane are e.g. chemical transfection like calcium-phosphate-precipitation [1], transfection via viral vectors [2,3] or physical techniques like electroporation [4,5]. However, all listed methods show disadvantages e.g. low efficiency, low throughput, toxicity, complex handling, limitation to specific cell lines or high cell damages [2-5]. Especially primary tissue cultures and stem cells remain difficult to transfect with established techniques. To avoid these problems an optical transfection technique has been developed using fs laser pulses. This technique provides a very gentle cell treatment with a cell viability of 70 % to 80 % [6,7] accompanied with a similar transfection efficiency. However, this method is based on tight focusing conditions, making cell and sample positioning difficult and leading to a limited number of transfected cells (single cell targeting). In the following we present nanoparticle assisted cell perforation by ultrashort laser pulses as an alternative transfection tool. Previous approaches to perforate the cell membrane employing nanoparticles and laser radiation were demonstrated by Yao et al. [8] using laser at wavelengths near the plasmon resonance and longer laser pulses. Another work from Pitsillides et al. used similar parameters for 20 nm gold particles to treat the cells [9]. Based on this and our preliminary work [6] we aimed at combining the effects of low energy fs-laser pulses and nanoparticles mediated permeabilization to transfer large molecules (DNA expression plasmids). 2. Materials and method 2.1 Cell preparation GFSHR-17 granulosa rat cells were cultivated in glass-bottom-dishes (MatTek) in DMEM8900 (Dulbecco’s Modified Eagle Medium). Constituents of this medium are 5% fetal calf serum (FCS), antibiotics penicillin, streptomycin and partricin. Therapeutic Laser Applications and Laser-Tissue Interactions IV, edited by Ronald Sroka, Lothar D. Lilge, Proc. of SPIE-OSA Biomedical Optics, SPIE Vol. 7373, 737308 · © 2009 SPIE-OSA CCC code: 1605-7422/09/$18 · doi: 10.1117/12.831903 SPIE-OSA Vol. 7373 737308-1