Development of antibacterial and antifungal silver-coated polyurethane foams as air filtration units for the prevention of respiratory diseases

The development of silver-coated polyurethane filters as filtration units for the prevention of the respiratory diseases. Methods and Results: An innovative silver deposition technology based on the photo-reduction in a silver salt was adopted. The efficacy of the technology in providing a homogeneous distribution of the silver particles was verified by scanning electron microscopy and energy dispersive X-ray spectroscopy. The materials were tested through microbiological procedures used in industry to verify the efficacy of the silver-coated filters on the viability and growth of selected micro-organisms. Direct inoculation test, filtration experiment and shaking tests were performed on microbial human pathogens associated with air filtration units and respiratory disease, namely Legionella pneumophila, Pseudomonas aeruginosa, Aspergillus niger and Aspergillus flavus, by adopting Escherichia coli and Staphylococcus aureus as control organisms. Conclusions: The results provided evidence of the effectiveness of the silver coating in reducing the bioaerosolization of viable human pathogens into environments using recirculated air. Significance and Impact of the Study: Micro-organisms can affect the air quality in indoor environments and can be responsible for infectious, allergic or toxic disturbances on human airways. The development of an adequate bioaerosol control might ameliorate a positive health effect in humans