Lubricious ionic polymer brush functionalised silicone elastomer surfaces

Abstract

Infection, erosion of mucosal and uro-epithelial layers, tissue trauma and encrustation associated with catheterisation is still an issue faced by health-care professionals and patients – effecting patients subject to spinal cord injuries, chemotherapy and incontinence to name a few. Over the past decade efforts have been made to optimise catheter surfaces in an attempt to reduce the occurrence of trauma related complications during insertion. Organic and inorganic materials have been mooted as potential methods of reducing bio-film formation and increasing lubricity. The use of charged species has been further hypothesised as a potential method to reduce the occurrence of bio-film formation, reducing the need for therapeutic intervention. This study investigates the feasibility of functionalising silicone surfaces with charged ionic polymer brush technologies with the view to reduce urethral trauma and infection for indwelling and self-catheterisation devices. A simple three step synthesis route has been proposed, complimented by surface analysis and tribological assessment of the surfaces. The effects of initial monomer content on the functional outcomes of the surfaces has been investigated. Functionalisation of surfaces was seen to significantly reduce the hydrophobicity of the surfaces. A significant reduction in the coefficient of friction from μ = 0.4 to 0.005 for un-functionalised and functionalised surfaces, respectively, was seen. The speed dependence and effects of lubricant chemistry on the coefficient of friction have also been investigated.