An in vitro study on the inhibition and ultrastructural alterations of Candida albicans biofilm by zinc oxide nanowires in a PMMA matrix

• Published in: The Saudi dental journal Vol. 33; no. 8; pp. 944 - 953
• Main Authors: Apip, Constanza, Martínez, Alejandra, Meléndrez, Manuel, Domínguez, Mariana, Marzialetti, Teresita, Báez, Ricardo, Sánchez-Sanhueza, Gabriela, Jaramillo, Andrés, Catalán, Alfonso
• Format: Journal Article
• Language: English
• Published: Saudi Arabia Elsevier B.V 01-12-2021; Elsevier
• Subjects: Biofilm; C. albicans; Nanowires; Original; Poly(methyl-methacrylate); Ultrastructural alteration; Zinc oxide; Biofilm; Zinc oxide; Ultrastructural alteration; Nanowires; C. albicans; Poly(methyl-methacrylate)
• ISSN: 1013-9052; 1658-3558
• DOI: 10.1016/j.sdentj.2021.08.006

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The purpose of this study was (i) to investigate whether nanocomposite poly(methyl-methacrylate)-zinc oxide nanowires (PMMA-ZnO-NWs) have C. albicans antibiofilm activity; (ii) to evaluate the interaction between components of the nanocomposites based on PMMA-ZnO-NWs by Raman spectroscopy; and (iii) to assess ultrastructural alterations.
Sixty-eight rectangles (17 PMMA (control) and 51 PMMA–ZnO-NWs (250, 500, 1000 ppm ZnO nanowires) were fabricated. C. albicans ATCC 10231 and a C. albicans clinical strain were tested. Adherence, biofilm formation and ultrastructural alterations were assessed by transmission electron microscopy. Raman mapping images and spectra were analyzed using main component analysis.
Nanocomposite PMMA-ZnO-NWs inhibited the formation of C. albicans biofilms 94% at 1000 ppm and 80% at 500 ppm against both C. albicans strains. PMMA-ZnO-NWs induced ultrastructural alterations, including cell wall damage and disorganization of the cytoplasmic membrane, resulting in cell lysis. Raman spectroscopy showed new vibrational modes (300–365–485–600 cm−1) for PMMA and ZnO-NW interactions.
PMMA-ZnO-NWs inhibited C. albicans dose-dependent biofilm formation and led to changes in the structures and cell membrane. Raman spectroscopy showed chemical interactions between ZnO-NWs and PMMA, as suggested by the appearance of new bands at 301 and 485 cm−1.