As an example of that, single-walled carbon nanotubes (SWNTs) were reported to have strong antimicrobial activities against microbes (Vecitis et al., 2010). Electrospun polymer mats with incorporated narrow diameter SWNTs were found to significantly reduce bacterial colonization and subsequent biofilm formation (Schiffman & Elimelech, 2011). Besides microbicidal agents, non-microbicidal agents are also used to block microbial attachment. For example, pathogens often bind human cell surface through pili and

form biofilm in vivo (Tsui et al., 2003; Okahashi et al., 2011). A 12-mer peptide (RQERSSLSKPVV), which binds to the structural protein PilS of the type IVB pili of Salmonella Typhi, was isolated by using a ribosome display system and shown to inhibit adhesion to or invasion of human monocytic THP-1 cells by piliated S. Typhi (Wu et al., 2005). This group also identified high-affinity Fluorouracil cell line single-stranded RNA aptamer [S-PS(8.4)] as a type IVB pilus-specific ligand and further showed that the aptamer [S-PS(8.4)] could significantly inhibit the entry of the piliated S. Typhi into human THP-1 cells (Pan et al., 2005).

Bovine lactoferrin was also shown to interact with cable pili of Burkholderia cenocepacia and efficiently inhibit invasion of alveolar epithelial cells by free-living bacteria or biofilm (Ammendolia et al., 2010). Increasing efforts have been put on development of modified surfaces with anti-adhesive properties by means of physicochemistry. For example, electropolished stainless steel was shown to significantly reduce attachment C59 wnt clinical trial and biofilm formation by bacterial cells than the sand-blasted and sanded stainless steel surfaces (Arnold & Bailey, 2000). Raulio et al. (2008) reported that hydrophilic

or hydrophobic coated stainless steel by diamond-like carbon or certain fluoropolymers could reduce or almost eliminate adhesion and biofilm formation by Staphylococcus epidermidis, Deinococcus geothermalis, Non-specific serine/threonine protein kinase Meiothermus silvanus and Pseudoxanthomonas taiwanensis (Raulio et al., 2008). A robust peptide-based coating technology for modifying the surface of titanium (Ti) metal through non-covalent binding was introduced by Khoo et al. (2009). In their study, a short HKH tripeptide motif containing peptide (e.g. SHKHGGHKHGSSGK) possessing affinity for Ti was identified by means of a phage display based screening and amino acid substitution study. Based on this peptide, a PEGylated analogue was found to rapidly coat Ti and efficiently block the adsorption of fibronectin and attachment of S. aureus (Khoo et al., 2009). Anti-adhesive properties and microbicidal properties are combined by researchers when designing novel surfaces. In a recent study, Yuan et al. (2011) immobilized lysozyme to the chain ends of poly(ethylene glycol) branches of the grafted poly(ethylene glycol) monomethacrylate (PEGMA) polymer after PEGMA was coated to stainless steel surfaces (Yuan et al., 2011).