The Oral Nanoscience group has a longstanding interest in antimicrobial biomaterials for dental, medical and recently veterinary use.

Research over the past 10 years led to a family of novel compounds of chlorhexidine, a common antiseptic. These materials differ significantly from conventional chlorhexidine compounds in that they exhibit much reduced solubility, thus releasing the active antiseptic gradually over an extended period. This provides the opportunity to develop materials and topicals that deliver a controlled dose of chlorhexidine over a period of time, whereas current chlorhexidine formulations provide a high dose of chlorhexidine at the initial application but this is rapidly dissipated and thus may be depleted to suboptimal concentrations. These materials have been the subject of patent applications, and are now being commercialised by a University spin-out company, Pertinax Pharma Ltd, based in north Bristol www.pertinaxpharma.com

Current University projects associated with these and other novel antimicrobial materials, many of which are in collaboration with Pertinax, include formulations to treat infectious foot disease in cattle, topical gels for the prevention of umbilical cord infection in neonates in low resource settings, and development of novel wound dressings to prevent wound infection. Collaborations in this area include academic staff at Bristol Vet School, Bristol Medical School and the School of Cellular and Molecular Medicine as well as Cardiff Metropolitan University, UWE and UHB.

Another interest of the group is the use of nanostructured materials to enhance mechanical properties of biomaterials. Nanoparticles are a useful tool when seeking to improve the strength and toughness of biomaterials, particularly those with high aspect ratio (rods, fibres, whiskers and plates). We are using such structures, particularly naturally occurring minerals, to reinforce and otherwise enhance materials including dental cements, in collaboration with academics in Chemistry and Engineering.