Product Code: ICAL08_N403

Two-Photon Polymerization of Protein Patterns with Nd:YAG Pulsed Laser
Authors:
Sanna Peltola, Tampere University of Technology, Department of Biomedical Engineering; Tampere Finland
Jouko Viitanen, VTT Technical Research Centre of Finland; Tampere Finland
Minna Kellomäki, Tampere University of Technology, Department of Biomedical Engineering; Tampere Finland
Presented at ICALEO 2008

In this paper an inexpensive and efficient fabrication method for precise manufacturing of protein (bovine serum albumin and avidin) patterns using two-photon polymerization (TPP) is presented. The methodology enables the patterning of cell culture dishes or tissue engineering scaffolds with nano- and micrometer scale protein patterns, which can guide the growth and differentiation of cultivated cells. The process is based on the use of visible light (532 nm) Q-switched Nd:YAG pulsed laser. When focused inside a photopolymerizable material the radiation initiates reaction, where two photons are absorbed simultaneously, thus leading to the polymerization of the material. In addition to pulsed laser, the upright microscope based custom built fabrication system is equipped with beam expander, shutter, attenuators, objective with high numerical aperture, motorized XYZ table and camera. The structures were fabricated by moving the motorized stage equipped with high resolution positioning controller. The code for running the instrument is written by inputting Cartesian coordinates into the WinPos operating system either by manually or by using a CAD drawing, which is converted into a format that is readable by the WinPos system. The system allows a rapid single step fabrication of solid, protein structures with a resolution down to submicron-size.