10:30-11:15

Understanding and Tailoring the Biological-Material Interface

Whilst significant advances have been made in the use of biomaterials to repair, replace or regenerate tissue, significant problems still persist. On implantation of a synthetic material in the body, a cascade of complex events (including protein adsorption, matrix formation, inflammation and fibrous encapsulation) occur which can often result in significant and unwanted complications. These arise in part from the“mismatch” between the surface of the implanted material and the biological environment. Simple approaches to enhance a materials’“biocompatibility” -an often used, but not understood term- have largely been discredited, as the modulation of a single surface characteristic (e.g. surface energy, water contact angle etc) cannot be used to direct a series of intricate biological events. More sophisticated approaches embrace the concept that biological events occur both spatially and temporally, and rely most importantly upon unique molecular recognition events.

In this talk I will review (briefly) some of the complications arising from the use of biomaterials in implantable devices and consider how, from a knowledge (of some) of the possible biological responses, more appropriate surfaces can be engineered at the molecular level to control and direct these events.

In our laboratory (in conjunction with the MacNeil group, University of Sheffield UK) we have developed technology based upon plasma polymerisation for engineering nanometre polymer films of defined chemistries. These have been developed for cell binding and release. They are being employed as coatings on bandages for the delivery of cells to wounds (1,2). Over the past decade they have been used in burns, scalds, diabetic wounds and leg ulcers.

In conjunction with the Day group (Oxford/Manchester University) we have developed novels surfaces for the binding of complex sugars that may form the basis of a new generation of therapeutics (3, 4). Using physical masks, and unique micron scale plasma sources (developed with Bradley's group at Liverpool and Eden's group, University of Illinois, USA) we have developed new technologies for the spatial patterning of surface chemistry (and topography) and of biological“cues” at the micron-scale.(4-6) These methods are being extended to create gradients of biological molecules over “biologically meaningful” scale lengths of a few ten of micrometers to about 0.5mm. Examples include directing neurite outgrowth; spatial patterning of different cell types to form pusedo-tissues in 2-D and control over stem cell differentiation into specific types of tissue.

1. Hernon Catherine A.; Dawson Rebecca A.; Freedlander Eric; et al, Regenerative Medicine, Volume: 1 Issue: 6 Pages: 809-821
2. MacNeil Sheila, Nature, 2008, Volume: 445 Issue: 7130 Pages: 874-880
3. Robinson David E.; Marson Andrew; Short Robert D et al, Advanced Materials, 2008, Volume: 20 Issue: 6 Pages: 1166-+
4. Marson A, Robinson DE, Brooks PN, et al, Glycobiology, 2009, 19(12), 1537-1546
5. Priest Craig; Gruner Philipp J.; Szili Endre J.; et al, Lab on a Chip, 2007, Volume: 11 Issue: 3 Pages: 541-544
6. Wells Nicola; Baxter Melissa A.; Turnbull Jeremy E, et al, Biomaterials, 2009, Volume: 30 Issue: 6 Pages: 1066-1070

Speaker

Professor Robert Short, Director of Mawson Institute, University of South Australia, Australia

Chair

Dr. Chen Guoping, MANA PI, MANA, NIMS