# Impact of Nb2O5 Coating Produced by Using the Reactive Sputtering Technique on Bacterial Biofilm Formation

## TL;DR

This study shows that coating titanium alloy surfaces with niobium pentoxide reduces bacterial biofilm formation and organic adsorption, making it a promising material for biomedical applications.

## Contribution

The novel contribution is demonstrating that Nb2O5 coatings modulate bacterial adhesion and biofilm formation in a species-specific manner on biomedical alloys.

## Key findings

- Nb2O5 coatings reduced E. coli biofilm coverage from 74.94% to 51.10% on Ti-6Al-4 V surfaces.
- Coated surfaces showed significantly lower organic retention (85.11%) compared to uncoated surfaces (99.83%).
- S. aureus adhesion was reduced on coated samples compared to uncoated ones, indicating species-specific effects.

## Abstract

The reactive sputtering
technique has been employed to deposit
niobium pentoxide (Nb2O5) thin films onto the
surfaces of the Ti-6Al-4 V alloy, which is widely used in trauma care
and tissue repair. This approach has shown significant potential in
enhancing the alloy’s resistance to uniform and localized corrosion,
as well as improving its wear and fatigue performance. In this study,
Nb2O5 thin films were deposited on Ti-6Al-4
V surfaces using reactive DC sputtering, and their biofilm-modulating
effects were evaluated in the presence of artificial saliva (AS) and
two clinically relevant bacteria strainsStaphylococcus
aureus ATCC 25923 (Gram-positive) and Escherichia coli ATCC 25922 (Gram-negative). The
extent of biofilm coverage, expressed as a percentage, was quantitatively
assessed using scanning electron microscopy (SEM) coupled with energy-dispersive
spectroscopy (EDS). This combined analytical approach allowed for
detailed morphological examination of the biofilm’s distribution.
Results demonstrated that the uncoated Ti-6Al-4 V surfaces exhibited
99.83% organic retention after saliva exposure and up to 74.94% biofilm
coverage with E. coli, while Ti-6Al-4
V/Nb2O5 specimens showed lower retention under
the same conditions (85.11 and 51.10%, respectively). Notably, S. aureus adhesion was markedly reduced on the coated
samples (67.42%) when compared to that on the AS sample (40.68%),
suggesting species-specific modulation of bacterial colonization.
These findings indicate that Nb2O5 coatings
can alter the surface wettability and biofilm architecture, reducing
nonspecific organic adsorption and selectively influencing bacterial
adhesion. This study underscored the potential of Nb2O5 coatings for the development of multifunctional biomedical
surfaces exhibiting both antimicrobial and biointeractive properties.