Histatin-5 Reduces C.Albicans Attachment on Hydrophilic TiO₂ Coated Titanium Surface

Objectives: The aim of the study is to investigate the attachment of histatin-5 (His-5) on non-coated titanium (NC) and hydrothermally induced TiO₂ coatings (HT)and its impact on the adhesion of Candida albicans (C. albicans) and Streptococcus sanguinis (S. sanguinis), to enhance antimicrobial properties.
Methods: Titanium discs (n=83, diameter 14 mm thickness 1 mm) were fabricated for the study. Half of the discs were provided with HT coatings. Half of the HT and NC discs were treated with His-5 solution (34 μg/ml). S. sanguinis and C. albicans were incubated separately on the treated discs for 1h. C albicans adhesion test was repeated on the discs with already attached S.sanguinis. The number of attached microbial cells was counted according to their colony formic units (CFU). Flow cytometry was performed on a subset of the samples to assess cell count and viability.
Results: HT coating of TiO₂ discs did not affect the microbial adhesion. His-5 treatment of the discs did not affect the adhesion of S. sanguinis but reduced the adhesion of C. albicans on both surfaces (NC: p=0.003, HT: p<0.001). On His-5 treated NC surfaces the pre-attachment of S. sanguinis had no effect on the C. albicans adhesion, but on His-5 treated HT surfaces pre-adhered S. sanguinis slightly reduced, but not abolished, the inhibitory effect of His-5 on C. albicans adhesion (p=0.03).
Conclusions: The Histatin-5 treatment of TiO₂ shows an anti-adherence effect against C. albicans. However, the presence of S. sanguinis reduces the inhibitory effect of His-5, potentially by masking the His-5 exposure or by synergistic interactions and microenvironmental changes favoring C. albicans attachment. Despite these interactions, His-5 treatment remains a promising approach for developing antimicrobial dental implants, as it consistently reduces C. albicans adhesion.