# Presentation: 076282

## Neutron Reflectometry Characterization of

**NIST**
**Keith M. Faucher,  Elliot L. Chaikof, M.D., Ph.D****.**
**Department of Surgery**
**Emory University School of Medicine**

**Neutron Reflectometry Characterization of**
** **
**Planar Soft-Supported Membrane-Mimetic Films**

## Membrane-Mimetic

- Water filled Soft Support
- Planar Substrate

## Biosensors

**Soft-Supported **
**Membrane-Mimetic**
**system**

- Simplify and Clarify
- Biological Systems

- Membrane-Mimetic
- Water filled Soft Support
- Planar Substrate

**Biofunctional Coatings:**
***Artificial Organs and Implanted Medical Devices***

## Polymeric-Phospholipid Monolayer Supported 

**by a Polyelectrolyte Multilayer**

- 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.

- Au

## Fabrication of an Alkylated Polyelectrolyte Multilayer

- Poly-L-Lysine (PLL)

- Alginate (ALG)

- PLL

- Terpolymer
- (TER)

## Vesicle Fusion and In-Situ Photopolymerization of a 

**Vesicle Fusion and In-Situ Photopolymerization of a **
**Planar Lipid Assembly on an Alkylated Polyelectrolyte Multilayer**

- Visible light
- EY/TEA/VP

## 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

## 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

## 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

## Paramteric B-Splines fitting procedure

- Polyelectrolyte +Terpolymer + Phospholipid dry

## Au

- PE

- 92% D2O humidity

**Scattering length density (x10****-6****Å****-2****)**

**Z (****Å****)**

## Au

- PE

- Terpolymer

- 92% D2O humidity

**Scattering length density (x10****-6****Å****-2****)**

**Z (****Å****)**

## Au

- PE

- Terpolymer
- Phospholipid

- 92% D2O humidity

**Scattering length density (x10****-6****Å****-2****)**

**Z (****Å****)**

## Au

- PE

- Terpolymer
- Phospholipid

- Polyelectrolyte + Terpolymer + Phospholipid

**Scattering length density (x10****-6****Å****-2****)**

**Z (****Å****)**

**dry**

## Au

- PE

- Terpolymer
- Phospholipid

**Scattering length density (x10****-6****Å****-2****)**

**Z (****Å****)**

**dry**

**D****2****O**

**H****2****O/D****2****O**

- Polyelectrolyte + Terpolymer + Phospholipid

## Polyelectrolyte + Terpolymer + Phospholipid

**dry**

**D****2****O**

## Au

- PE

- Terpolymer
- Phospholipid

**Z (****Å****)**

- Water Distribution in
- Polyelectrolyte + Terpolymer + Phospholipid layer

## Conclusion

-  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.

_**Conclusion**_

## 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.

## Acknowledgements

- Anne Plant
- John T. Elliot
- Vitalii Silin
- Biotechnology Division NIST