A layer of protein molecules will attach and grow on foreign materials like medical implants when they are put into a living organism.
By using experiments and theories which have been developed to understand this growth, the researchers have identified the key steps which are important for proteins to form this layer.
The research shows that proteins first stick to a surface then they slide around until they meet each other and join together to form clusters. These clusters are also able to slide around, although not as quickly, and can then stick together to create even bigger clusters. This movement results in a surface which is covered in isolated islands of protein molecules separated by large areas of bare surface.
For medical and dental implants, knowledge about the arrangement of protein molecules on a surface is important, because it is these molecules which interact directly with the surrounding tissue. The way in which proteins initially attach to a surface influences how cells then grow and this has implications for the integration or rejection of any implanted material. If proteins were fixed at the first point of attachment, then this would create a very different surface distribution with different properties.
‘Our work into the ways in which proteins attach and cluster on solid surfaces will help to develop better biocompatible materials for use in implants,’ said Dr Roger Bennett, from the Departments of Chemistry and Physics. ’In contrast to previous ideas, which were based on simple models, our experiments and modelling show the actual behaviour of proteins.
‘Our research has investigated how proteins attach to surfaces by mimicking the immersion of artificial materials, such as medical and dental implants, in biological solutions, for example blood or saliva, then visualising the results by using a technique known as Atomic Force Microscopy.’