Fabrication of porous biopolymer substrates for cell growth by UV laser: The role of pulse duration

Ultraviolet laser irradiation using pulses with duration from the nanosecond to the femtosecond range was investigated aiming at the generation of a foam layer on films of the biopolymers chitosan, starch and their blend. We report on the morphological characteristics of the foams obtained upon irradiation and on the accompanying laser induced photochemistry, assessed by on line monitoring of the laser induced fluorescence. We identify the laser conditions (pulse duration) at which foaming is produced and discuss the obtained results in reference to the material properties, particularly extinction coefficient and thermal parameters. This article also reports on successful cell culture on the laser induced foam structure generated in chitosan, as an illustrative example of the possibility of broader use of laser induced biopolymer foaming structures in biology.Funding from Ministry of Science and Innovation of Spain (MICINN) under Project CTQ2010-15680. E.R., M.O. and M.S. gratefully acknowledge Juan de la Cierva, CONSOLIDER CSD2007-00058, and Geomateriales (CAM, S2009/Mat-1629) Programs for contracts. The research leading to these results has received support from the access activities of the EC FP7-Infrastructures-2007 Project “Laserlab-Europe II” (grant agreement no: 212025) operating at the Ultraviolet Laser Facility, IESL-FORTH. Prof. S. Lazare is acknowleged for useful discussions and A. Manousaki for SEM measurements.Peer Reviewe