# Antibacterial properties of polydopamine-modified ZnO nanoparticles composite films for oral therapeutic applications

## TL;DR

Researchers developed a nanocomposite film that can be used on oral instruments to prevent bacterial growth and biofilm formation.

## Contribution

A novel ZnO@PDA/Zein nanocomposite film with enhanced antibacterial efficacy and biocompatibility is introduced.

## Key findings

- The film showed antibacterial effects against Gram-negative bacteria at 1.2 mg/mL concentration.
- At 0.6 mg/mL, the film was effective against Gram-positive bacteria like S. aureus and S. mutans.
- The film demonstrated good biocompatibility and potential for preventing biofilm formation on oral instruments.

## Abstract

In this work, a solvent evaporation casting approach was used to prepare ZnO@PDA/Zein nanocomposite films, where polydopamine-modified zinc oxide nanoparticles (ZnO@PDA NPs) were incorporated into a zein matrix as the film-forming agent. This nanocomposite film adhered uniformly to the surface of oral therapeutic instruments and exhibited good antibacterial effects. At a doping concentration of 1.2 mg/mL, the film exhibited an antibacterial effect against Gram-negative bacteria such as Escherichia coli (E. coli), and at a doping concentration of 0.6 mg/mL, the film exhibited antibacterial effects against Gram-positive bacteria such as Staphylococcus aureus (S. aureus) and Streptococcus mutans (S. mutans), along with good biocompatibility. This study introduces a novel ZnO@PDA/Zein nanocomposite film with enhanced antibacterial efficacy and biocompatibility, offering a promising solution for preventing biofilm formation on oral therapeutic instruments.

The online version contains supplementary material available at 10.1186/s11671-025-04421-5.