Electrografted mixed organic monolayers as antibacterial coatings for implantable biomedical devices

Bacterial infections associated with the implantation of biomedical devices belong to one of the leading causes of their failure. Accordingly, novel methods of surface modifications are highly required to prevent bacterial adhesion and limit the use of antibiotics. Electrochemical grafting of organic moieties is a well-known method of surface modification at the nanoscale level, allowing for the modulation of surface wettability, roughness, and the ability to enhance/reduce cellular adhesion, among others. In this work, the presence of an organic coating formed through the electrografting of a mixture of diazonium salts is proposed to tailor interactions between the surface and a living matter. Through the application of diazonium compounds possessing different functional groups, it is possible to alter electrochemical and surface properties, as well as cell survivability and anti-adhesive activity towards bacteria. It is shown that the presence of organic layers results in 4.5-fold increase in the wettability of the surface and 1.5-fold increase in roughness, leading to the 84% decrease in bacterial adhesion without affecting surface's biocompatibility. In this way, mixed organic monolayers formed through the electroreduction of a mixture of diazonium salts can serve as antibacterial coatings suitable for implantable biomedical devices.