Bacterial Interactions with Immobilized Liquid Layers

• Published in: Advanced healthcare materials 2017-08, Vol.6 (15), p.n/a
• Main Authors: Kovalenko, Yevgen, Sotiri, Irini, Timonen, Jaakko V. I., Overton, Jonathan C., Holmes, Gareth, Aizenberg, Joanna, Howell, Caitlin
• Format: Article
• Language: English
• Subjects: Adherent cells; Adhesion; bacteria; Bacteria - classification; Bacteria - cytology; Bacterial Adhesion - physiology; Biocompatible Materials - chemistry; biofilms; Cell Size; Coated Materials, Biocompatible; Dimethylpolysiloxanes - chemistry; Disruption; Flagella; Growth conditions; Heart; infections; Interfaces; Materials Testing; Oil; oil‐infused polymers; Polymers; Pseudomonas aeruginosa; Silicone Oils - chemistry; slippery liquid‐infused porous surfaces; Species Specificity; Staphylococcus aureus; Surface Properties
• ISSN: 2192-2640; 2192-2659
• DOI: 10.1002/adhm.201600948

Bacterial interactions with surfaces are at the heart of many infection‐related problems in healthcare. In this work, the interactions of clinically relevant bacteria with immobilized liquid (IL) layers on oil‐infused polymers are investigated. Although oil‐infused polymers reduce bacterial adhesion in all cases, complex interactions of the bacteria and liquid layer under orbital flow conditions are uncovered. The number of adherent Escherichia coli cells over multiple removal cycles increases in flow compared to static growth conditions, likely due to a disruption of the liquid layer continuity. Surprisingly, however, biofilm formation appears to remain low regardless of growth conditions. No incorporation of the bacteria into the layer is observed. Bacterial type is also found to affect the number of adherent cells, with more E. coli remaining attached under dynamic orbital flow than Staphylococcus aureus, Pseudomonas aeruginosa under identical conditions. Tests with mutant E. coli lacking flagella confirm that flagella play an important role in adhesion to these surfaces. The results presented here shed new light on the interaction of bacteria with IL layers, highlighting the fundamental differences between oil‐infused and traditional solid interfaces, as well as providing important information for their eventual translation into materials that reduce bacterial adhesion in medical applications. The number of bacterial cells adherent on an immobilized liquid layer of silicone oil is significantly affected by the presence or absence of orbital flow, the species of bacteria, and the bacterial cell morphology. In all tested experimental conditions, however, immobilized liquid layers show superior resistance to irreversible bacterial adhesion compared to equivalent solid polydimethylsiloxane surfaces.