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Ursula A. Perez-Salas, Susan Krueger, Charles F. Majkrzak, Norman F. Berk NIST

This study utilizes neutron reflectometry to analyze the water distribution and formation of a membrane monolayer in a polyelectrolyte-terpolymer-phospholipid film system.

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Ursula A. Perez-Salas, Susan Krueger, Charles F. Majkrzak, Norman F. Berk NIST

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  1. Neutron Reflectometry Characterization of Planar Soft-Supported Membrane-Mimetic Films Ursula A. Perez-Salas, Susan Krueger, Charles F. Majkrzak, Norman F. Berk NIST Keith M. Faucher, Elliot L. Chaikof, M.D., Ph.D. Department of Surgery Emory University School of Medicine

  2. Membrane-Mimetic Water filled Soft Support Planar Substrate

  3. Membrane-Mimetic Water filled Soft Support Planar Substrate Soft-Supported Membrane-Mimetic system Simplify and Clarify Biological Systems Biosensors Biofunctional Coatings: Artificial Organs and Implanted Medical Devices

  4. Polymeric-Phospholipid Monolayer Supported by a Polyelectrolyte Multilayer Polymeric Phospholipid Multifunctional Terpolymer Poly Lysine (+) Alginate (-) Poly Lysine (+) Au Liu H., Faucher K.M., Sun X.-L., Feng J., Johnson T.L., Orban J.M., Apkarian R.P., Dluhy R.A., Chaikof E.L. Langmuir, 2002, 18, p.1332.

  5. Fabrication of an Alkylated Polyelectrolyte Multilayer Poly-L-Lysine (PLL) Alginate (ALG) Terpolymer (TER) PLL

  6. Vesicle Fusion and In-Situ Photopolymerization of a Planar Lipid Assembly on an Alkylated Polyelectrolyte Multilayer Visible light EY/TEA/VP

  7. Goal • Determine the water distribution in the Polyelectrolyte+ • Terpolymer+Phospholipid system • 2) Infer if there is a single monolayer of Phospholipid over the • Polyelectrolyte+ Terpolymer layers

  8. Neutron Reflectivity Measurements: • NG1 vertical stage Reflectometer at the NCNR at the NIST • q range: 0.01 to 0.3 Å-1 • - samples inside a humidity chamber: ~ 92% • - two humid atmospheres used: • a)100% D2O • b) 50% D2O and 50% H2O • - temperature set to approximately 20°C

  9. Measure

  10. Film Film Substrate 1 Substrate 2 Measure Surround Variation Method Berk N.F., Majkrzak C.F. J. Phys. Soc. Jpn., 1996, 65, p.81 Majkrzak C.F., Berk N.F. Phys. Rev. B., 1998, 58, p.15416 Majkrzak C.F. Acta Phys. Pol. A., 1999, 96, p.81 Majkrzak C.F., Berk N.F.,Silin V., Meuse C.W. Phys. B., 2000, 283, p.248

  11. Polyelectrolyte +Terpolymer + Phospholipid dry Paramteric B-Splines fitting procedure Majkrzak C.F., Berk N.F. Phys. Rev. B., 1995, 52, p.10827

  12. 92% D2O humidity Scattering length density (x10-6Å-2) PE Au Z (Å)

  13. 92% D2O humidity Terpolymer Scattering length density (x10-6Å-2) PE Au Z (Å)

  14. 92% D2O humidity Terpolymer Phospholipid Scattering length density (x10-6Å-2) PE Au Z (Å)

  15. Polyelectrolyte + Terpolymer + Phospholipid dry Terpolymer Phospholipid Scattering length density (x10-6Å-2) PE Au Z (Å)

  16. Polyelectrolyte + Terpolymer + Phospholipid dry D2O Terpolymer Phospholipid H2O/D2O Scattering length density (x10-6Å-2) PE Au Z (Å)

  17. Polyelectrolyte + Terpolymer + Phospholipid dry D2O

  18. Water Distribution in Polyelectrolyte + Terpolymer + Phospholipid layer Terpolymer Phospholipid PE Au Z (Å)

  19. Conclusion • PE+Terpolymer+phospholipid supported membrane-mimetic shows 40% water content in the “cushion” (PE) layer under humid conditions • Because fusing phospholipid vesicles onto the PE+Terpolymer film does not change the thickness of the film significantly it can be inferred that a membrane monolayer was formed.

  20. Future Work • Study all three films, ie, polyelectrolyte film, polyelectrolyte plus terpolymer film and polyelectrolyte plus terpolymer plus crosslinked PC film completely hydrated in D2O and in a 50/50% D2O/H2O mixture. • Fuse deuterated lipid vesicles on to the polyelectrolyte plus terpolymer film while completely hydrated. • Get a crosslinkable deuterated phospholipid • Measure biologically active surfaces.

  21. Acknowledgements Anne Plant John T. Elliot Vitalii Silin Biotechnology Division NIST

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