| Pacific Rim Symposium on Surfaces, Coatings and Interfaces (PacSurf 2016) | |
| Biomaterial Surfaces & Interfaces | Monday Sessions |
| Session BI-MoE |
| Session: | Soft Surface & Biofunctional Coatings |
| Presenter: | Lisbeth Grondahl, The University of Queensland, Australia |
| Correspondent: | Click to Email |
The surface of a material is the first contact with the cellular environment upon inoculation (in vitro) or implantation (in vivo) and as such these surfaces must, at minimum, possess properties amenable to cell adhesion. However, many polymers used as biomaterials lack functional moieties and the overall hydrophobic nature of the polymers encourage non-specific protein adsorption and make them less than ideal for controlled protein attachment and hence directed cell attachment and expansion.
One method of changing the surface properties of polymeric biomaterials is graft copolymerisation of functional polymers thereby providing functional groups and/or reduced hydrophobicity to the material. Work will be presented on graft copolymerisation of both the biodegradable polymer polycaprolactone (PCL), an FDA approved aliphatic semicrystalline polyester studied extensively for tissue engineering, and the biostable polymer expanded polytetrafluoroethylene (ePTFE), used for example in facial reconstruction. The ability to modify the interior of scaffolds and membranes as well as introducing various functional groups (eg. phosphate, carboxylate and amine) will be illustrated. Recent studies on creation of dual functional materials will show how the approach taken (one-pot or consecutive grafting) affects the material properties.
Protein adsorption studies using albumin, lactoferrin and lysozyme illustrate that the surface density of carboxylate groups does not correlate to the amount of adsorbed protein rather a correlation to the degree of grafting was observed indicating penetration of the proteins into the grafted layers. Furthermore, the topology of the graft copolymer is shown to be more important than the functional group in regards to the outcome of in vitro mineralisation when comparing a series of phosphate and carboxylate functionalised surfaces.