title: Inhibition of Escherichia coli and Proteus mirabilis adhesion and biofilm formation on medical grade silicone surface.
abstract: Silicone has been utilized extensively for biomedical devices due to its excellent biocompatibility and biodurability properties. However, its surface is easily colonized by bacteria which will increase the probability of nosocomial infection. In the present work, a hydrophilic antimicrobial carboxymethyl chitosan (CMCS) layer has been grafted on medical grade silicone surface pre-treated with polydopamine (PDA). The increase in hydrophilicity was confirmed from contact angle measurement. Bacterial adhesion tests showed that the PDA-CMCS coating reduced the adhesion of Escherichia coli and Proteus mirabilis by ≥ 90%. The anti-adhesion property was preserved even after the aging of the functionalized surfaces for 21 days in phosphate-buffered saline (PBS), and also after autoclaving at 121°C for 20 min. Both E. coli and P. mirabilis readily form biofilms on the pristine surface under static and flow conditions but with the PDA-CMCS layer, biofilm formation is inhibited. The flow experiments indicated that it is more difficult to inhibit biofilm formation by the highly motile P. mirabilis as compared to E. coli. No significant cytotoxicity of the modified substrates was observed with 3T3 fibroblasts.
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, Kent Ridge, Singapore 119260, Singapore.
authors.forename: Rong
authors.initials: R
authors.lastname: Wang
authors.forename: Koon Gee
authors.initials: KG
authors.lastname: Neoh
authors.forename: Zhilong
authors.initials: Z
authors.lastname: Shi
authors.forename: En-Tang
authors.initials: ET
authors.lastname: Kang
authors.forename: Paul Anantharajah
authors.initials: PA
authors.lastname: Tambyah
authors.forename: Edmund
authors.initials: E
authors.lastname: Chiong
mesh_terms: D016475:3T3 Cells; D000704:Analysis of Variance; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry* / Q000494:pharmacology; D001422:Bacterial Adhesion / Q000187:drug effects*; D018441:Biofilms / Q000187:drug effects*; D048271:Chitosan / Q000737:chemistry / Q000494:pharmacology; D004926:Escherichia coli / Q000187:drug effects / Q000502:physiology*; D007211:Indoles / Q000737:chemistry / Q000494:pharmacology; D051379:Mice; D011108:Polymers / Q000737:chemistry / Q000494:pharmacology; D011513:Proteus mirabilis / Q000187:drug effects / Q000502:physiology*; D012828:Silicones / Q000737:chemistry*; D013499:Surface Properties
chemical_list: D000890:Anti-Infective Agents; D007211:Indoles; D011108:Polymers; D012828:Silicones; C568283:polydopamine; D048271:Chitosan