title: Biocompatibility of layer-by-layer self-assembled nanofilm on silicone rubber for neurons.
abstract: Electrostatic layer-by-layer (LbL) self-assembly, a novel method for ultrathin film coating has been applied to silicone rubber to encourage nerve cell adhesion. The surfaces studied consisted of precursor layers, with alternating cationic poly(ethyleneimine) (PEI) and anionic sodium poly(styrenesulfonate) (PSS) followed by alternating laminin and poly-D-lysine (PDL) layers or fibronectin and PDL layers. Film growth increased linearly with the number of layers. Every fibronectin/PDL and laminin/PDL bilayer was 4.4 and 3.5 nm thick, respectively. All layers were more hydrophilic than the unmodified silicone rubber surface, as determined from contact angle measurements. Of the coatings studied, a PDL layer was the most hydrophilic. A multilayer film with composition [PSS/PEI]3+[fibronectin/PDL]4 or [PSS/PEI]3+[laminin/PDL]4 was highly favorable for neuron adhesion, in contrast to bare silicone rubber substrate. The film coated on silicone rubber is biocompatible for cerebellar neurons with active viability, as shown by lactate dehydrogenase (LDH) assay and fluorescence cellular metabolism observations. These results demonstrate that LbL self-assembly provides an effective approach to apply films with nanometer thickness to silicone rubber. Such only few nanometer thick films are biocompatible with neurons, and may be used to coat devises for long-term implant in the central nervous system.
authors.affiliation: Department of Biomedical Engineering and Institute for Micromanufacturing, Louisiana Tech University, Ruston, LA 71272, USA.
authors.forename: Hua
authors.initials: H
authors.lastname: Ai
authors.forename: Hongdi
authors.initials: H
authors.lastname: Meng
authors.forename: Izumi
authors.initials: I
authors.lastname: Ichinose
authors.forename: Steven A
authors.initials: SA
authors.lastname: Jones
authors.forename: David K
authors.initials: DK
authors.lastname: Mills
authors.forename: Yuri M
authors.initials: YM
authors.lastname: Lvov
authors.forename: Xiaoxi
authors.initials: X
authors.lastname: Qiao
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis / Q000494:pharmacology*; D018929:Cell Culture Techniques / Q000379:methods; D051379:Mice; D036103:Nanotechnology / Q000379:methods*; D009474:Neurons / Q000166:cytology* / Q000187:drug effects*; D012826:Silicone Elastomers / Q000138:chemical synthesis / Q000494:pharmacology*
chemical_list: D001672:Biocompatible Materials; D012826:Silicone Elastomers