title: Antifouling performance of cross-linked hydrogels: refinement of an attachment model.
abstract: Poly(ethylene glycol) dimethacrylate (PEGDMA), PEGDMA-co-glycidyl methacrylate (PEGDMA-co-GMA), and PEGDMA-co-hydroxyethyl methacrylate (PEGDMA-co-HEMA) hydrogels were polymerized using ammonium persulfate and ascorbic acid as radical initiators. Surface energies of the hydrogels and a standard, poly(dimethylsiloxane) elastomer (PDMSe), were characterized using captive bubble and sessile drop measurements, respectively (γ = 52 mN/m, γ(0) = 19 mN/m). The chemical composition of the hydrogels was characterized by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. All three hydrogel compositions reduced significantly (p = 0.05) initial attachment of zoospores of the green alga Ulva linza (up to 97%), cells of the diatom Navicula incerta (up to 58%) and the bacterium Cobetia marina (up to 62%), compared to a smooth PDMSe standard. A shear stress (45 Pa), generated in a water channel, eliminated up to 95% of the initially attached cells of Navicula from the smooth hydrogel surfaces relative to smooth PDMSe surfaces. Compared to the PDMSe standard, 79% of the cells of C. marina were removed from all smooth hydrogel compositions when exposed to a 50 Pa wall shear stress. Attachment of spores of the green alga Ulva to microtopographies replicated in PEGDMA-co-HEMA was also evaluated. The Sharklet AF microtopography patterned, PEGDMA-co-HEMA surfaces reduced attachment of spores of Ulva by 97% compared to a smooth PDMSe standard. The attachment densities of spores to engineered microtopographies in PDMSe and PEGDMA-co-HEMA were shown to correlate with a modified attachment model through the inclusion of a surface energy term. Attachment densities of spores of Ulva to engineered topographies replicated in a material other than PDMSe are now correlated with the attachment model (R(2) = 0.80).
authors.affiliation: J Crayton Pruitt Family Department of Biomedical Engineering, The University of Birmingham, Birmingham B15 2TT, UK.
authors.forename: Chelsea M
authors.initials: CM
authors.lastname: Magin
authors.forename: John A
authors.initials: JA
authors.lastname: Finlay
authors.forename: Gemma
authors.initials: G
authors.lastname: Clay
authors.forename: Maureen E
authors.initials: ME
authors.lastname: Callow
authors.forename: James A
authors.initials: JA
authors.lastname: Callow
authors.forename: Anthony B
authors.initials: AB
authors.lastname: Brennan
mesh_terms: D020100:Hydrogels / Q000737:chemistry*; D008956:Models, Chemical; D013499:Surface Properties
chemical_list: D020100:Hydrogels