A membrane-mimetic barrier for cell encapsulation

Academic Article

Abstract

  • A stabilized, membrane-mimetic film was produced on a polyelectrolyte multiplayer (PEM) by in-situ photopolymerization of an acrylate functonalized phospholipid assembly at a solid-liquid interface. The phospholipid monomer was synthesized, prepared as unilamellar vesicles, and fused onto close-packed octadecyl chains as part of an amphiphilic terpolymer anchored onto the PEM by electrostatic interactions. The lipid film displayed an advancing contact angle of ∼ 60°, elemental composition, as determined by X-ray photoelectron spectroscopy, was in agreement with that anticipated for a lipid membrane. Data obtained from both high-resolution scanning electron microscopy and ellipsometry were consistent with the formation of a supported lipid monolayer. In addition, polarized external reflection infrared spectroscopy revealed significant acyl chain ordering induced on lipid fusion and polymerization. Doping the lipid assembly with a fluorescein terminated polymerizable lipid provided visible confirmation of film formation and its stability under a variety of conditions, including shear rates of 2000 sec-1. Transport studies demonstrated that the addition of a lipid film significantly reduced barrier permeability for compounds in excess of 70 kD. The ability to coat microbeads (d ∼ 300 μm) with a robust membrane-mimetic film, while preserving encapsulated cell viability is illustrated, thereby establishing a new strategy for modulating the physiochemical and biological properties of immunoisolation barriers for cell transplantation.
  • Authors

    Published In

  • Langmuir  Journal
  • Digital Object Identifier (doi)

    Pubmed Id

  • 3793094
  • Author List

  • Liu H; Faucher KM; Sun XL; Feng J; Johnson TL; Orban JM; Apkarian RP; Dluhy RA; Chaikof EL
  • Start Page

  • 1332
  • End Page

  • 1339
  • Volume

  • 18
  • Issue

  • 4