Manufacture of Chemically Modified Antibacterial Surfaces

Abstract

It is well-known that the prevention of biofilm formation on medical implants is a highly desirable outcome for world-wide patient care. The lack of new antibiotic discoveries and the build-up of resistance towards existing antibiotics, particularly in biofilms, are proving a major global challenge to infection control and causing high mortality rates, which is exacerbated by the contamination of implant surfaces. The chemical modification of implants has proved to be very promising in preventing bacterial attachment over the past few decades, but despite the huge consequential reduction in bacterial attachment rates, no solution yet exists for preventing the attachment of bacteria and the subsequent formation of biofilms; it is generally recognised in the field of biomaterials surface science that it is possible to change the rate but not the fate of biofilm formation. This chapter provides an overview of the state of the art in the field of manufacture of chemically modified surfaces that are produced in an effort to minimise the formation of biofilms. A summary of the role of adsorbed biomolecules present in the environment surrounding implants is provided. This is an additional complicating factor, since we hypothesise that preventing biomolecular adsorption onto the surface of implants is needed to resolve the issue of implant-centred infection. Such an outcome therefore requires the development of novel surface modification strategies and perhaps more than one concept to improve the effectiveness of a coating. In this respect we summarise techniques such as the use of hydrophilic polymer layers and plasma polymers, self-cleaning surfaces, and combinations of controlled release of bactericidal molecules. In addition, we propose other novel antibacterial surface modification strategies. We also highlight that preventing the initial attachment of bacteria is a fundamental requirement in preventing biofilm formation, since a biofilm can form once a single bacterium has attached to a substrate surface.