title: Methacrylate Polymer Scaffolding Enhances the Stability of Suspended Lipid Bilayers for Ion Channel Recordings and Biosensor Development.
abstract: Black lipid membranes (BLMs) provide a synthetic environment that facilitates measurement of ion channel activity in diverse analytical platforms. The limited electrical, mechanical and temporal stabilities of BLMs pose a significant challenge to development of highly stable measurement platforms. Here, ethylene glycol dimethacrylate (EGDMA) and butyl methacrylate (BMA) were partitioned into BLMs and photopolymerized to create a cross-linked polymer scaffold in the bilayer lamella that dramatically improved BLM stability. The commercially available methacrylate monomers provide a simple, low cost, and broadly accessible approach for preparing highly stabilized BLMs useful for ion channel analytical platforms. When prepared on silane-modified glass microapertures, the resulting polymer scaffold-stabilized (PSS)-BLMs exhibited significantly improved lifetimes of 23 ± 9 to 40 ± 14 h and > 10-fold increase in mechanical stability, with breakdown potentials > 2000 mV attainable, depending on surface modification and polymer cross-link density. Additionally, the polymer scaffold exerted minimal perturbations to membrane electrical integrity as indicated by mean conductance measurements. When gramicidin A and α-hemolysin were reconstituted into PSS-BLMs, the ion channels retained function comparable to conventional BLMs. This approach is a key advance in the formation of stabilized BLMs and should be amenable to a wide range of receptor and ion channel functionalized platforms.
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721.
authors.forename: Leonard K
authors.initials: LK
authors.lastname: Bright
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721.
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Baker
authors.affiliation: Endocrine and Sarcoma Surgery Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Karolinska University Hospital, SE-171 76 Stockholm, Sweden.
authors.forename: Robert
authors.initials: R
authors.lastname: Bränström
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721; BIO5 Institute, University of Arizona, Tucson, AZ 85721.
authors.forename: S Scott
authors.initials: SS
authors.lastname: Saavedra
authors.affiliation: Department of Chemistry and Biochemistry, University of Arizona, Tucson, AZ 85721; BIO5 Institute, University of Arizona, Tucson, AZ 85721; Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85721.
authors.forename: Craig A
authors.initials: CA
authors.lastname: Aspinwall
keywords: Black Lipid Membrane; Gramicidin; Ion Channel; Lipid Bilayer; Methacrylate Polymer; Polymer Scaffold; α-Hemolysin