| AVS 59th Annual International Symposium and Exhibition | |
| Biomaterial Interfaces | Monday Sessions |
| Session BI-MoA |
| Session: | Cell-Surface Interactions: High Throughput Methodologies |
| Presenter: | B.R. Coad, University of South Australia |
| Correspondent: | Click to Email |
Biomaterial research is primarily concerned with mediating the interaction of biological species at the surface of materials. Therefore, research into new ways of coating and derivatizing surfaces is advancing this field. Coating surfaces with thin plasma polymer layers is advantageous because fragmentation and recombination of organic compounds in the plasma phase allows for surface deposition leading to covalent anchoring of polymer networks that retain the functionality of the parent compounds. This is useful as a platform strategy, providing a substrate-independent path for modifying different classes of bulk materials so that they retain their bulk properties (hardness, softness, conductivity, inertness etc.).
In this presentation, we show how deposited plasma polymers form interlayers that allow further surface modification of 1) surface chemistry and 2) surface topology and relate these to their use as biomaterials.
In the first approach, we have constructed a bioconjugation platform that allows for covalent capture of proteins in a gradient fashion. Simultaneous gradient plasma polymerization of two compounds under a mask along a moving stage allows for an increasing surface density of reactive aldehyde groups to be place alongside an inert hydrophilic spacer allowing for specific, yet variable attachment to be mediated across the surface. We have used this platform to capture streptavidin on the surface to which we have bound biotinylated signaling probes to investigate T-Cell binding and specificity. This platform is shown to be useful in further immunological studies investigating T-Cell binding to gradients of assembled human major histocompatibility complex analogs.
In the second approach, the surface topology has been modified with polymer brushes. With controlled radical polymerization from a novel macroinitiator, it is possible to generate polymer brushes of variable thickness and density which in turn modify the surface interaction with proteins and cells. Polymer chains which are present in highly ordered array provide an entropic barrier to surface fouling and cell attachment. The advantage of using plasma polymer interlayers is that the substrate-independent procedure allows for coatings with the same topology to be grafted, for example, from the surface of a hard, inert metal or from a flexible, polymeric film.
We conclude by showing a few other examples of the use of plasma polymerization for biomaterials applications from our latest work.