Pulsed laser deposition of biocompatible polymers: a comparative study in case of pullulan

We report some results of a comparison between thin films of pullulan biopolymer obtained by pulsed laser deposition (PLD) and matrix-assisted pulsed laser evaporation (MAPLE). In experiments we used a KrF* laser source generating pulses of 248 nm and 20 ns pulse duration. We demonstrate by Fourier transformed infrared spectroscopy (FTIR) that MAPLE is more appropriate than conventional PLD for transfer with high structural fidelity of biopolymers from target to substrate. In case of MAPLE, besides FTIR spectra, atomic force microscopy micrographs and scanning electron microscopy images prove that the film composition and structure strongly depend on the solvent used for the targets preparation: distilled water, ethylene glycol, ethanol, tert-butanol and dimethyl sulfoxide. Our best results for pullulan deposition were obtained using dimethyl sulfoxide as a solvent. This is the first report of successful MAPLE deposition of this material as thin films. (C) 2003 Elsevier B.V. All rights reserved.