Theme Lectures

Pankaj VADGAMA

Queen Mary, University of London, UK

Lecture Date: Tuesday, 3 July 2007
Time: 13:00 to 13:45 hrs

Designer Surfaces for the Biological Interface – How Far can we Enhance Functional Performance?

The optimisation of materials interfaces for targeted medical applications, has enhanced the performance of both in vitro and in vivo devices. Key factors that influence interfacial properties are the charge, polarity, mobility and geometric organisation of molecular motifs at surfaces, for it is these which provide the surface cues that condition cellular and colloidal interactions with materials surfaces. Thus, for vascular contact materials such as stents, surface deployment of molecules conferring different charge and surface energies has a strong effect on the coagulation cascade. Biologically informed approaches have also been important, e.g. use of phosphorylcholine, anticoagulant, and cytotoxic agents as slow release components. One contentious issue is the need for continued pharmacological action at an active implant vs surface redesign. The real question is, whether any designer modifications at surfaces can provide a long lasting solution to the problem of long-term biocompatibility.

The current state of progress has provided basic ground rules for designing surfaces, but failure associated with chronic implants appears to override much of the improvements seen over the short term or in the laboratory. The next stage of research is likely to focus more on nanoscale motifs at surfaces; nanoparticles certainly promote quite different interfacial processes compared with their macroscopic counterparts. The contrasts will provide new insights into design requirements and a new opportunity for nanotechnology in medicine.

The range and sophistication of new strategies for surface modification based both on chemistry and oligomeric structures will be explored in this presentation. New candidate materials undergoing laboratory evaluation will be explored and suggestions made for promising and less promising, directions for research. It will also be proposed that work on the organisation of water at and near surfaces, needs to move up the list of research priorities since solvation ultimately governs the behaviour of both cells and macromolecular structures.