Bacterial adhesion and interaction with biomaterial surfaces

A larger number of research studies has been carried out and significant achievements have been made in understanding the mechanisms of bacterial adhesion and controlling the bacterial adhesion to biomaterials. However, microbial infection still remains a serious problem for long term use of implanted medical devices. This is partially because bacterial adhesion is a very complicated process that is affected by many factors such as material surfaces and environments. The other reason is that the bacterial surface compositions/structures and their functional roles in bacterial adhesion and biofilm formation are still not clear. For example, future studies may need to address the functions of PIA, AaP, Bhp or Embp in S. epidermidis adhesion and biofilm formation, as well as their responses to antibiotics.26 Understanding the molecular interaction at the material-bacteria interface is fundamental to controlling bacterial adhesion to biomaterial surfaces. The major point in bacterial adhesion appears to be the role of proteins adsorbed on surfaces. The conformational structure and biological function of proteins adsorbed are affected by material surface properties (e.g., surface chemistry, nanotopography) and they in turn influence bacterial adhesion. Future research in this field will need to better address the correlation of nanoscale surface properties and protein conformation, and correlate to the biological response bacterial adhesion. Certainly, this will rely on a better analysis and understanding of the influence of nanoscale surface properties on quantity and conformational structure of proteins adsorbed, and will require a development of new techniques or an improvement of the existing techniques to obtain this information. One representative example in this field is the increased use of novel, high-resolution AFM techniques for imaging surfaces and mapping the interactions of material and bacteria. Furthermore, combinations of AFM with other characterization methods such as confocal microscopy and Raman spectroscopy168,193,194 greatly expanded the amount and types of data one can obtain simultaneously, and greatly help to know the molecular mechanisms of bacterial responses to adhering surfaces.