Özet:

In this study, plasma polymerization technique for the production of antimicrobial surfaces was studied to inhibit the formation of biofilm of Staphylococcus aureus (S. aureus) and Candida albicans (C. albicans) for foreign materials in biomedical application. Low pressure RF-plasma system was used to coat Ti surfaces. Ti surfaces were exposed to diethyl phosphite (DEP) plasma generated with different discharge power varying from 25-90 W for 1-10 min of exposure times at a constant pressure of 0.15 mbar. Surface hydrophobicity and surface energies of unmodified and DEP modified Ti surfaces were used to enlighten surface wettability by the sessile drop method using contact angle analyser. All DEP coatings produced with different plasma conditions increased both the surface hydrophilicity from 100° to 30-48° and surface energies of Ti surfaces from 33mJ/m2 to 61-71mj/m2. Aging of the DEP coatings on Ti surfaces was analyzed in terms of change in surface energies by time within 30 days. Even though the stability of phosphorus containing thin films has been problematic due to the post-plasma oxidation, thin films produced with 25 W-5 min, 50 W-5 min, 75 W-10 min and 90 W-1 min were found more stable compared to the others. The antibacterial and antifungal activity of unmodified and DEP modified Ti surfaces was studied against S. aureus and C. albicans, respectively. While the adhesion and growth of both bacteria and fungi was observed on unmodified Ti surfaces, antimicrobial activity was observed after surface modification with DEP plasma with different plasma conditions. The highest efficiency for anti-fungal coating was obtained with 50 W-5 min, 75 W-10 min and 90 W-10 min and the highest antibacterial activity was achieved with 25 W- 1min, 50W-5 min, 50 W-10 min and 75 W-10 min. Additionally, surface modification with DEP plasma increased L929 fibroblast cell viability of Ti surfaces. The chosen precursor, DEP, solves problems in reducing the risk of infection associated with Ti implants with plasma polymerization technique.

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