Biofilm Resistant Liquid-like Solid Surfaces in Flow Situations

Biofilms are microbial cells embedded within a self-secreted extracellular polymeric substance (EPS) matrix which adhere to substrates. Biofilms are central to some of the most urgent global challenges across diverse fields of application, from medicine to industry to the environment and exert considerable economic and social impact. For example, catheter-associated urinary tract infections (CAUTI) in hospitals has been estimated to cause additional health-care costs of £1-2.5 billion in the United Kingdom alone (Ramstedt et al, Macromolec. Biosci. 19, 2019) and to cause over 2000 deaths per year (Feneley et al, J. Med. Eng. Technol. 39, 2015).

To combat biofilm growth on surfaces, chemical-based approaches using immobilization of antimicrobial agents (i.e. antibiotics, silver particles) can trigger antimicrobial resistance (AMR), but are often not sustainable. Alternatively, bio-inspired nanostructured surfaces (e.g. cicada wing, lotus leaf) can be used, but their effects often may not last.

A recent innovation in creating slippery surfaces has been inspired by the slippery surface strategy of the carnivorous Nepenthes pitcher plant. These slippery surfaces involve the impregnation of a porous or textured solid surface with a liquid lubricant locked-in to the structure. Such liquid surfaces have been shown to have promise as antifouling surfaces by inhibiting the direct access to the solid surface for biofilm attachment, adhesion and growth. However, the antibiofilm performance of these new liquid surfaces under flow conditions remains a concern due to flow-induced depletion of lubricant. Here we propose a novel anti-biofilm surface by creating permanently bound slippery liquid-like solid surfaces. Success would transform our understanding about bacteria living on surfaces and open-up new design paradigms for the development of next generation antibiofilm surfaces for a wide range of applications (e.g. biomedical devices and ship hulls).

To enable the successful delivery of this project, it requires us to combine cross-disciplinary skills ranging from materials chemistry, physical and chemical characterisations of materials surfaces, nanomechanics, microbiology, biomechanics, to computational mechanics. The project objectives well align with EPSRC Healthcare Technologies Grand Challenges, addressing the topics of controlling the amount of physical intervention required, optimizing treatment, and transforming community health and care. In parallel, we shall contribute to the advancement of Cross-Cutting Research Capabilities (e.g. advanced materials, future manufacturing technologies and sustainable design of medical devices) that are essential for delivering these Grand Challenges. In particular, this research will employ nanomechanical tests to determine bacteria adhesion and microfluidics techniques for biofilm characterisation, which enables us to create novel approaches in computational engineering through the formulation and validation of sophisticated numerical models of bacteria attachment and biofilm mechanics.