Report

Teaser, summary, work performed and final results

Periodic Reporting for period 1 - NoBios (No Biofouling Surfaces)

Teaser

PROBLEM: Adhesion and accumulation of microorganisms on surfaces in contact with liquid medium.SOCIAL IMPACT: Prevention of biofilms is of extreme relevance in industry and science as they are ubiquitous and able to provoke corrosion or failure in pipelines, heat exchangers...

Summary

PROBLEM: Adhesion and accumulation of microorganisms on surfaces in contact with liquid medium.

SOCIAL IMPACT: Prevention of biofilms is of extreme relevance in industry and science as they are ubiquitous and able to provoke corrosion or failure in pipelines, heat exchangers, biomedical devices, artificial implants or food processing facilities. Thus, biofilm formation leads to economical losses and, more importantly, to human health impact when related to implant and/or devices need to replacement and nosocomial infections.

OBJECTIVES AND APPROACH OF NoBios: Biofilms are often battled with antibiotics, but bacterial resistance is a major issue. Therefore, novel approaches are required to avoid biofouling. We will explore the application of (1) superamphiphobic coatings, (2) slippery liquid infused porous surfaces and (3) functional pillar arrays surfaces to battle biofilms. These surfaces have in common that they strongly repel water, blood, organic liquids, and even soap-water mixtures due to a synergy between rough topography and a special chemistry. We will monitor and characterize the adhesion of bacteria, proteins and cells to these surfaces depending on shape, size and chemical composition of the surface and the liquids. Several classical and highly advanced cutting edge methods will be used to investigate the wetting and fouling properties of these surfaces, especially laser scanning confocal microscopy and X-ray photoelectron spectroscopy. In the final steps of the research, we will evaluate the robustness of the surfaces and the biocompatibility in order to establish potential real applications.

Work performed

Biofilms are often battled with antibiotics, but bacterial resistance is a major problem. Therefore, the Nobios project proposed exploring the use of super-liquid repellent surfaces (superhydrophobic, superamphiphobic and liquid-infused) to battle biofilms . These surfaces have in common that they strongly repel water, blood, organic liquids, and even soap-water mixtures due to a synergy between rough topography and a special chemistry. This approach proposes battling biofilm formation on the very first stages of biofilm formation, before bacteria undergo irreversible attachment on surfaces (Fig. 1). During the realization of the NoBios grant, I have investigated the use of super-liquid repellent surfaces to hinder-delay the formation of biofilms. Several approaches were followed, based on the use of hierarchically patterned surfaces with hydrophobic chemical functionalization. These processes rendered materials able to entrap air pockets between deposited liquids and the solid interface, thus easy roll-off of the liquid phase is allowed.
The obtained results have proved the non-fouling ability of liquid-repellent coatings by checking protein adsorption and bacterial adhesion through cutting-edge and surface-sensitive methods, including laser scanning confocal microscopy (LSCM), X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS). The investigation has produced important results reported in 5 published publications and 4 more under preparation. The NoBios project information has been also disseminated in 8 International conferences and 2 invited talks.

Final results

The investigations included in the NoBios project have contributed to the knowledge and development of surfaces able to hinder or delay the adsorption of proteins and biofilm formation. Therefore, new materials for the control of infection can be produced. We have shown that bio-contamination of devices is a size and time scale event, thus the combination of liquid mobility (self-cleaning ability) and reduced contact area to minimize non-specific interaction with biological entities is a promising route to overcome the problem of biofouling.