In parallel with our innovative studies on the fundamentals of polyelectrolyte multilayers and complexes, we have studied these same systems at the biological interface. For more than a decade, our group, in collaboration with Prof. Tom Keller from the biology department, has been investigating the attachment of cells (such as smooth muscle cells) and proteins (serum albumin, actin, fibronectin) on normal or specially designed polyelectrolyte multilayers.
Polyelectrolyte films have been altered in many ways to render them more cytophilic or cytotoxic. The effect of properties such as hydrophobicity vs. hydrophilicity, the binding of extracellular matrix components to the surface, as well as gradient of film modulus on cell behavior were investigated. Using smooth muscle cells allowed us to observe a transition of motility depending on the surface charge. We also compared how cells respond to the individual polymers versus how they behave when cultured on the complex. Understanding more about the subject directs the applications of thin films towards active biomedical coatings.