Inactivation of Bacterial and Viral Bioaerosols by Lactoferrin-Coated Filters Under Various Environmental Conditions

This study developed a novel antimicrobial air filter by functionalizing polypropylene nonwoven fabrics with bovine lactoferrin peptide to control indoor bioaerosols. The filtration performance was evaluated against E. coli and  virus under various environmental conditions. Results demonstrated broad-spectrum inactivation efficacy, with the 2.0 mg coating achieving the highest performance in a dose-dependent manner. A critical breakthrough was the environmental stability of the lactoferrin coating; unlike traditional biopolymers, its antimicrobial efficiency remained consistent across 30–70% relative humidity (p > 0.05). Furthermore, a field test conducted in a dental clinic validated its practical feasibility, achieving an 83.3% reduction in bacterial bioaerosols over a 210-min operation. These findings suggest that lactoferrin-functionalized filters offer a robust, moisture-resistant, and safe solution for improving indoor air quality in high-risk environments.