Mariana Fraga - TiO2 coatings via atomic layer deposition on polyurethane and polydimethylsiloxane substrates: Properties and effects on C. albicans growth and inactivation process

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      Publication Details (including relevant citation   information):

      R.S. Pessoa, V.P. dos Santos, S.B. Cardoso, A.C.O.C. Doria, F.R.   Figueira, B.V.M. Rodrigues, G.E. Testoni, M.A. Fraga, F.R.   Marciano,  A.O. Lobo, H.S. Maciel. TiO2 coatings   via atomic layer deposition on polyurethane and   polydimethylsiloxane substrates: Properties and effects   on C.   albicans growth and inactivation process. Applied   Surface Science (2017).

      DOI: 10.1016/j.apsusc.2017.05.254



      Atomic layer deposition (ALD) surges as an attractive technology   to deposit thin films on different substrates for many advanced   biomedical applications. Herein titanium dioxide     (TiO2)     thin films were successful obtained on polyurethane (PU) and     polydimethylsiloxane (PDMS) substrates using ALD. The effect of     TiO2 films     on Candida     albicans growth and inactivation process were also     systematic discussed. TiCl4 and     H2O     were used as precursors at 80 °C, while the reaction cycle     number ranged from 500 to 2000. Several chemical, physical and     physicochemical techniques were used to evaluate the growth     kinetics, elemental composition, material structure, chemical     bonds, contact angle, work of adhesion and surface morphology     of the ALD TiO2 thin     films grown on both substrates. For microbiological analyses,     yeasts of standard strains of C.     albicans were grown on non- and TiO2-coated     substrates. Next, the antifungal and photocatalytic activities     of the TiO2 were     also investigated by counting the colony-forming units (CFU)     before and after UV-light treatment. Chlorine-doped amorphous     TiO2 films     with varied thicknesses and Cl concentration ranging from 2-12%     were obtained. In sum, the ALD TiO2 films     suppressed the yeast-hyphal transition of C.     albicans onto PU, however, a high adhesion of yeasts     was observed. Conversely, for PDMS substrate, the yeast     adhesion did not change, as observed in control. Comparatively     to control, the TiO2-covered     PDMS had a reduction in CFU up to 59.5% after UV treatment,     while no modification was observed to TiO2-covered     PU. These results pointed out that ALD chlorine-doped amorphous     TiO2 films     grown on biomedical polymeric surfaces may act as fungistatic     materials. Furthermore, in case of contamination, these     materials may also behave as antifungal materials under UV     light exposure.  



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