A Coating that Combines Lotus‐Effect and Contact‐Active Antimicrobial Properties on Silicone

Abstract

The antimicrobial equipment of materials is of great importance in medicine but also in daily life. A challenge is the antimicrobial modification of hydrophobic surfaces without increasing their low surface energy. This is particularly important for silicone‐based materials. Because most antimicrobial surface modifications render the materials more hydrophilic, methods are needed to achieve antimicrobial activity without changing the high water‐contact‐angle. This is achieved in the present work, where SiO2 nanoparticles are prepared and functionalized with 3‐(trimethoxysilyl)‐propyldimethyloctadecyl ammonium chloride (QAS) in a one‐pot synthesis. The modified nanoparticles are applied onto a silicone surface from suspension with no need of elaborate pretreatment. The resulting surface exhibits a Lotus‐Effect combined with contact‐active antimicrobial properties. The particle surfaces show self‐organizing micro‐ and nanostructures that afford a water‐contact angle of 144° and a hysteresis below 10°. The particles are self‐adhering on the silicone after solvent evaporation and resistant against immersion into and washing with water for at least 5 d. Thereby, the adhesion of the bacterial strain Staphylococcus aureus to these surfaces is reduced and the remaining bacterial cells are killed within 16 h. This is the first example of a Lotus‐Effect surface with intrinsic contact‐active antimicrobial properties.

Novel modified QAC antimicrobial coatings: application, evaluation and functional determination

“…63,64 Along with modifying QACs to contain sulfonamide functionality, there has also been investigations into modifying compounds to increase hydrophobicity. Recently, Tiller et al 65 investigated combining silane-anchored QACs with silicon nanoparticles to produce a coating that exhibits the hydrophobic lotus-leaf effect, while still exhibiting antimicrobial characteristics. This concept was performed by functionalizing silicon nanospheres with QAC compounds before depositing the nanoparticles onto a silica-coated sample.…”

“…This produced a rough nanostructure that helped to repel water from the material surface and exhibited antimicrobial properties against Gram-positive Staphylococcus aureus. 65…”

Superwettable Surface Engineering in Controlling Cell Adhesion for Emerging Bioapplications

“…Another explanation of superhydrophobic surface for antibacterial adhesion is the so‐called lotus effect. [ 270 ] The bacterial solution would flow away on the superhydrophobic surface due to the small contact angle hysteresis (below 10°). The residual bacteria would be killed by the modification of quaternary ammonium salts (3‐(trimethoxysilyl)‐propyldimethyloctadecyl ammonium chloride).…”

Poly(ionic liquid)/Ce‐Based Antimicrobial Nanofibrous Membrane for Blocking Drug‐Resistance Dissemination from MRSA‐Infected Wounds

“…In recent years, poly(ionic liquids) (PILs), formed from IL monomers, have aroused considerable attention in the field of antimicrobial cationic polymer materials, due to their molecular designability and chemical stability. [ 45–48 ] It is known that the cationic groups of PILs can disrupt the negatively charged bacterial cell wall through the electrostatic interaction, while the hydrophobic segments of PILs can insert into the hydrophobic cell membrane, leading to the death of microbes, as well as the selectivity to bacteria over human cells. [ 49–57 ]…”