MEASUREMENT OF ADHESION AT POLYMER AND BIOMOLECULAR INTERFACES

 

Adam J. Nolte, Heqing Huang, and Christopher M. Stafford

Polymers Division, MSEL

 

            Measuring the strength of macromolecular interactions with surfaces is important for understanding a variety of interfacial phenomena.  This is particularly true in the field of biomaterials, where protein adsorption and cell adhesion and proliferation can be important markers for the success or failure of a candidate biomaterial.   Here we demonstrate a straightforward and flexible method for measuring relatively weak adhesion interactions between polymer surfaces.  This technique, based on the contact mechanics theory of Johnson, Kendall, and Roberts, allows one to find the interfacial energy between a hemispherical lens and a flat substrate during a loading-unloading cycle.  Using various surface functionalization techniques such as polyelectrolyte multilayer deposition and polymer brushes, we are able to quantify adhesion arising from factors such as hydrophobic effects and acid-base interactions.  In addition to functioning in the “dry” state, the instrument can also perform measurements in aqueous environments of controlled pH and ionic strength, making it ideal for characterizing biological interactions in relevant environments.  We demonstrate this capability by measuring the adhesion between an avidin-functionalized lens and a biotinylated substrate.

 

Author: Adam J. Nolte (not Sigma Xi member)

Mentor: Christopher M. Stafford (Sigma Xi member)

Polymers Division (854), MSEL

Bldg. 224, Rm. B226, Stop 8542

Phone: 301-975-2895

Fax: 301-975-4924

Email: adam.nolte@nist.gov

 

Poster Category: Biotechnology