Comparative Study of Candida albicans Inactivation by Nonthermal Plasma on Stainless Steel with and without Diamond-like Carbon Film

Autor(es)

Menegatti de Oliveira, Simone Maria ^{[1, 2]} ; da Silva, Newton Soares ^[3] ; Sene, Ana ^[1] ; Gandra, Rinaldo Ferreira ^[2] ; Boff Junges, Daniele Schaab ^[2] ; Ramirez Ramos, Marco Antonio ^[1] ; Vieira, Lucia ^[1]

Afiliação do(s) autor(es)

^[1] Univ Paraiba Valley, Lab Nanotechnol & Plasma Proc, BR-12244000 Sao Jose Dos Campos, SP - Brazil

^[2] Western Parana State Univ, Lab Mycol, BR-85819110 Cascavel, PR - Brazil

^[3] Univ Paraiba Valley, Lab Cell Biol & Tissue, BR-12244000 Sao Jose Dos Campos, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ACS OMEGA; v. 4, n. 4, p. 6891-6902, APR 2019.
• Citações Web of Science: 0

Resumo

This paper reports the efficacy of nonthermal plasma (NTP) as a biocidal agent to treat 304 stainless steel (SS304) covered with a diamond-like carbon (DLC) film contaminated with Candida albicans biofilms. The association of two techniques using electric plasma was used. The first was plasma-enhanced chemical vapor deposition (PECVD) used to deposit a DLC film on the SS304. The second was NTP used on the surface of the SS304 with and without the DLC film. The combination of the SS304 surface with the DLC film was demonstrated to be effective when using the DLC film as corrosion protection. Comparing the proliferation of Candida species on the DLC film and SS304 surface, it was possible to conclude that Candida species stays longer in the DLC film than in SS304. The reduction of colony numbers was visible after 5 min using plasma on both surfaces; in addition, 99% of Candida species were eliminated after 15 min. Three C. albicans microorganisms were used. Two were from samples of urine and tracheal secretion, and one was from the American Type Culture Collection (ATCC \#90028). Characterization of the plasma chemical species was performed using optical emission spectroscopy in order to understand the nature of the chemical species that inactivated the microorganisms. The DLC film was analyzed using profilometry, Raman spectroscopy, scanning electron microscopy, and tribocorrosion tests. The tribocorrosion tests were used to evaluate the effectiveness of the DLC film in protecting the SS304 surface against corrosion in simulated body fluid because corrosion species from the SS304 could interfere in biofilm growth and mask the effect of the plasma. The results of the factorial analysis of variance confirmed the statistical significance (p > 0.05) of the plasma as a biocidal agent, considering the reduction of colony-forming units of C. albicans. It was found that exposure of the samples to the plasma for only 5 min resulted in reductions ranging from 96.4 to 100.0% for all the microorganisms studied. (AU)

• Processo FAPESP: 13/20054-8 - Estudos de adesão, proliferação e de morte celular na interação de células com materiais nanoestruturados
• Beneficiário: Newton Soares da Silva
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 17/10491-2 - Produção de revestimentos multifuncionais para alto desempenho como lubrificante sólido e proteção contra corrosão para componentes aeroespaciais e dispositivos biomédicos
• Beneficiário: Lúcia Vieira
• Modalidade de apoio: Auxílio à Pesquisa - Regular