Probing into dynamic friction of soft contact materials for addressing mucosal dryness

Mucosal dryness initiated by lubrication failure is a leading cause of wear and life-threatening infections with morbidity and mortality consequences. Xerostomia i.e. dry mouth, which affects nearly 1 in 10 adults, 1 in 3 older adults and 80% of institutionalized elderly population leads to impaired eating, swallowing and eventually malnutrition, with the latter resulting in a £7.3 billion annual healthcare burden to the NHS, UK. Currently, numerous mucosal therapies are available, but none of them offer long-lasting relief.  Often, such mucosal technologies are based on design principle of rheology-modification which offers the needed hydration, but limits their translation.  In particular, many therapies fail to stick effectively to the diseased tissue interface and the therapies do not consider the important boundary lubrication performance, which is much-needed in these high demanding bio-lubrication failure situations.

This multidisciplinary PhD project aims to address this unmet clinical and societal needs by creating a novel class of durable microgel-reinforced hydrogel based lubricant formed via electrostatic self-assembly that offers both boundary and fluid film lubrication. In order to design such a new meta-material, it is important to investigate and understand how microgels interact with tissue-mimetic surfaces that are deficient in mucosal lining. This project will therefore a) develop the first of its kind tribo-microscope by coupling a high speed fluorescence microscopy with a bespoke tribocell that will be applied to optimized biomimetic, rough surfaces with various degrees of salivary coating obtained from dry mouth patients and healthy controls to probe dynamic friction, 2) fabricate microgel-based lubricants with tailored heterogeneity, and c) explore binding of the lubricants to primary epithelial cells from mucosal surfaces of patients creating a true replica of the diseased condition that will be vital for developing the therapy.