TY - JOUR A1 - Duarte Bernardino, Carolina A1 - Lee, Mihyun A1 - Ren, Qun A1 - Ruehle, Bastian T1 - Facile Spray-Coating of Antimicrobial Silica Nanoparticles for High-Touch Surface Protection N2 - The rising threat from infectious pathogens poses an ever-growing challenge. Metal-based nanomaterials have gained a great deal of attention as active components in antimicrobial coatings. Here, we report on the development of readily deployable, sprayable antimicrobial surface coatings for high-touch stainless steel surfaces that are ubiquitous in many healthcare facilities to combat the spread of pathogens. We synthesized mesoporous silica nanoparticles (MSNs) with different surface functional groups, namely, amine (MSN-NH2), carboxy (MSN-COOH), and thiol groups (MSN-SH). These were chosen specifically due to their high affinity to copper and silver ions, which were used as antimicrobial payloads and could be incorporated into the mesoporous structure through favorable host−guest interactions, allowing us to find the most favorable combinations to achieve antimicrobial efficacy against various microbes on dry or semidry high-touch surfaces. The antimicrobial MSNs were firmly immobilized on stainless steel through a simple two-step spray-coating process. First, the stainless steel surfaces are primed with sprayable polyelectrolyte solutions acting as adhesion layers, and then, the loaded nanoparticle dispersions are spray-coated on top. The employed polyelectrolytes were selected and functionalized specifically to adhere well to stainless steel substrates while at the same time being complementary to the MSN surface groups to enhance the adhesion, wettability, homogeneity, and stability of the coatings. The antimicrobial properties of the nanoparticle suspension and the coatings were tested against three commonly found pathogenic bacteria, Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli, as well as a fungal pathogen, Candida albicans. Especially MSN-SH loaded with silver ions showed excellent antimicrobial efficacy against all tested pathogens under application-relevant, (semi)dry conditions. The findings obtained here facilitate our understanding of the correlation between the surface properties, payloads, and antimicrobial activity and show a new pathway toward simple and easily deployable solutions to combat the spread of pathogens with the help of sprayable antimicrobial surface coatings. KW - Mesoporous silica nanoparticles KW - Thin films KW - Antimicrobial coatings KW - Spray-coating KW - Infectious diseases KW - Pathogen transmission KW - High-touch surfaces PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-626269 DO - https://doi.org/10.1021/acsami.4c18916 SN - 1944-8252 SP - 1 EP - 13 PB - ACS Publications CY - Washington, DC AN - OPUS4-62626 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Lee, Mihyun A1 - Wiesli, Luzia A1 - Schreiber, Frank A1 - Ivask, Angela Ivask A1 - Ren, Qun T1 - Quantitative Assessment of Microbial Transmission onto Environmental Surfaces Using Thermoresponsive Gelatin Hydrogels as a Finger Mimetic under In Situ-Mimicking Conditions N2 - Surface-mediated transmission of pathogens plays a key role in healthcare-associated infections. However, proper techniques for its quantitative analysis are lacking, making it challenging to develop novel antimicrobial and anti-fouling surfaces to reduce pathogen spread via environmental surfaces. This study demonstrates a gelatin hydrogel-based touch transfer test, the HydroTouch test, to evaluate pathogen transmission on high-touch surfaces under semi-dry conditions. The HydroTouch test employs gelatin as a finger mimetic, facilitating testing with pathogenic bacteria under controlled conditions. The thermoresponsive sol–gel transition of gelatin allows easy recovery and quantification of bacteria before and after testing. The HydroTouch test demonstrates that methicillin-resistant Staphylococcus aureus has a high transmission efficiency of ≈16% onto stainless steel, compared to <3% for Escherichia coli or Pseudomonas aeruginosa. Polyurethane surfaces exhibit strong resistance to bacterial contamination with a transmission efficiency of ≈0.6%, while polytetrafluoroethylene shows a transmission efficiency approximately four times higher than polyurethane. Additionally, quaternary ammonium-based antimicrobial coatings reduce the transmission efficiency of live bacteria on stainless steel to ≈4% of the original level. The HydroTouch test provides a reliable method for assessing pathogen transmission on various surfaces under semi-dry settings, supporting the development of effective antimicrobial, anti-transmission coatings to reduce healthcare-associated infections. KW - Antimicrobial surfaces KW - Biocides KW - Antimicrobial resistance KW - Standardization PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-624566 DO - https://doi.org/10.1002/adhm.202403790 SN - 2192-2659 SP - 1 EP - 10 PB - Wiley VHC-Verlag AN - OPUS4-62456 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -