[Zurück]

A. Daskalova, A. Trifonov, I. Bliznakova, C. Nathala, A. Ajami, W. Husinsky, H. Declercq, I. Buchvarov:
"Selective cell response on natural polymer bio-interfaces textured by femtosecond laser";
Applied Physics A: Materials Science & Processing, 124 (2018), 2; S. 20701 - 20718.

This study reports on the evaluation of laser processed natural polymer-chitosan, which is under consideration as a biointerface
used for temporary applications as skin and cartilage substitutes. It is employed for tissue engineering purposes,
since it possesses a significant degree of biocompatibility and biodegradability. Chitosan-based thin films were processed
by femtosecond laser radiation to enhance the surface properties of the material. Various geometry patterns were produced
on polymer surfaces and employed to examine cellular adhesion and orientation. The topography of the modified zones was
observed using scanning electron microscopy and confocal microscopy. Test of the material cytotoxicity was performed
by evaluating the life/dead cell correlation. The obtained results showed that texturing with femtosecond laser pulses is
appropriate method to initiate a predefined cellular response. Formation of surface modifications in the form of foams
with an expansion of the material was created under laser irradiation with a number of applied laser pulses from N = 1-5.
It is shown that irradiation with N > 5 results in disturbance of microfoam. Material characterization reveals a decrease in
water contact angle values after laser irradiation of chitosan films. Consequently, changes in surface roughness of chitosan
thin-film surface result in its functionalization. Cultivation of MC3T3 and ATMSC cells show cell orientational migration
concerning different surface patterning. The influence of various pulse durations (varying from τ = 30-500 fs) over biofilms
surface was examined regarding the evolution of surface morphology. The goal of this study was to define the optimal laser
conditions (laser energy, number of applied pulses, and pulse duration) to alter surface wettability properties and porosity
to improve material performance. The acquired set of results indicate the way to tune the surface properties to optimize
cell-interface interaction.