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Recycling 2019 & Material Science 2019
July 22-23, 2019
Volume 3
Journal of Environmental Geology
Material Science and Nanotechnology
Global Recycling Summit
July 22-23, 2019 | Rome, Italy
6
th
International Conference on
&
Magnetron co-sputtered TiO
2
/SiO
2
/Ag thin coatings inhibiting bacterial adhesion and
biofilm formation
Todorka Vladkova
University of Chemical Technology and Metallurgy, Bulgaria
P
rotection of medical devices against infections is a significant current challenge raised by increasing number of medical
devices associated infections and microbial resistance to conventional antibiotic and multi drugs treatments. Deposition of
antimicrobial coatings is one of the current approaches to solution the problem.
The aim of this study was to develop protective coatings for medical devices with improved antibacterial activity, combining the
known positive effects of TiO
2
, SiO
2
and Ag nanoparticles, and employing magnetron co-sputtering as an ecology friendly and
relatively easy technology. Magnetron co-sputtered TiO
2
/SiO
2
/Ag coatings with different Ag content were fabricated by varying
the area of the Ag sheds at constant area of the TiO
2
target and SiO
2
sheds.
Surface characteristics, influencing the bioadhesion: chemical composition, topography, wettability and surface energy were
estimated by SEM/EDX, XPS and contact angle measurement, respectively. The inhibitory effect toward bacterial growth on the
new developed TiO
2
/SiO
2
/Ag coatings was tested using both,
E. coli
and
P. aeruginosa
. Bacterial biofilm formation in urine flow
was evaluated for better characterization of the antimicrobial activity of these coatings.
SEM observation depicted a grain structure of the TiO
2
/SiO
2
/Ag composite coatings with homogeneous dispersion of the Ag
nanoparticles. Significant antibacterial activity as well as reduced biofilm formation in urine flow were found: approaching to
zero number of leaving
E. coli
and
P. aeruginosa
bacterial cells in the eluate detected after 1-3 h in contact with the studied
coatings and significantly decreased, as compared to a silicon surface, biofilm formation after 24-48 h in urine flow.
Observed by SEM, direct contact killing and indicated by FAAS, released silver-mediated killing were proposed as a mechanism
of antibacterial action of the studied coatings. Inhibiting bacterial adhesion and biofilm formation, as fabricated magnetron co-
sputtered TiO
2
/SiO
2
/Ag coatings, are promising protection for medical devices as indicated by in vitro testing, including in flow.
Biography
Vladkova has her expertise in surface engineering starting as a member of a pioneering group in the development of brush type PEG
coatings (Coll&Surf,1986) to create bioinert biomaterial surfaces, that do not cause non-desirable response reactions. Later she moves
to bioactive biomaterials and material surfaces: bio-integrating biomimetic nanocomposites for bone tissue engineering; antimicrobial
collagen based nanocomposites; marine biofouling preventing composition coatings; magnetron sputtered antibacterial coatings
for medical devices, etc. Inhibition of bioadhesion and biofilm formation as well as surface characteristics, influencing biofouling
(medical and marine) are in the focus of her investigations with a special emphasis on the non-toxic biofouling control including super
hydrophobic surfaces utilization.
tgv@uctm.eduTodorkaVladkova
,JEnvironGeol. |Volume3
ISSN:2591-7641