In the past several decades, different techniques have been developed to prevent microbial adhesion to biomaterial surfaces. Most of these techniques involve changing the surface chemistry of biomaterials. Surface charge, hydrophobicity and hydrophilicity strongly influence the extent of microbial adhesion. In general, hydrophilic and negatively charged surfaces prevent bacterial activity by inhibiting bacterial adhesion. Researchers first came across this phenomenon while studying the effect of increasing hydrophobicity and charge on the adhesion of three different strains of Escherichia coli on different poly(methacrylate) surfaces. In this study, it was found that significantly more bacteria adhered onto more hydrophobic and positively charged surfaces than to negatively charged and hydrophilic surfaces (Harkes et al., 1991). This was among the first findings that led researchers to develop many different surface coatings. Today, the most commonly employed hydrophilic coatings are based on polyethylene glycol (PEG) and polyethylene oxide (PEO)..