Meeting report

1st annual Biomaterials Workshop

[Biomaterials group]

The Biomaterials Workshop was hosted by Cranfield U. (Shrivenham, UK) on March 17, 2003. It was the inaugural launch of a series of such meetings designed particularly to introduce new researchers to more established workers in the field and present new and emerging areas. The meeting attracted more than 80 delegates from as far away Spain and Belgium.

P. Marquis (U. of Birmingham) described conventional and new material systems for use as dental restorative materials. He convinced everyone that finding alternatives to metallic amalgams is a high technology challenge and described the potential benefits of newly developed nano-particulates as they can provide the material quality and aesthetics required. A. Lloyd (U. of Brighton), presented a method for enhancing osteointegration through exploitation of part of the natural mineralisation process, describing the role of calcium-binding phospholipids within matrix vesicles and Prof. Lloyd showed how such lipids can, in vitro, self assemble into 3-D gels that may provide a suitable environment for rapid calcification.

Different fabrication routes to produce apatite coatings were discussed by D. Grant (U. of Nottingham). Coatings formed by plasma spraying and laser ablation were compared with respect to their chemistry, surface topography and cell interaction. He emphasized the need to apply absorption corrections in diffraction measurements of crystallinity and pointed out the lack of any ASTM methodology in this respect. J. Knowles described the use of phosphate based glasses as biomaterials, and explained how the solubility of such materials can be significantly modified through the addition of Na or Ca ions. These glasses are relatively soluble in contrast to the bioglasses traditionally employed as biomaterials. He went on to show that, by annealing the glasses to crystallization, the subsequent phase mix can be employed to determine the amorphous structure. One use of such glasses is as 3-D fibre network structures to support cell growth systems. P. Wilshaw (U. of Oxford) described a novel approach to formation of a strongly adherent bioactive coating based upon a nanoporous alumina ceramic. The advantage of this technology is that pore diameter can be easily controlled and that these pores are typically ~0.2μm, which is significantly lower than conventional porous materials used for biomaterial applications. Very low dissolution rates in culture media & osteoblasts were reported (0.03% in 10 days) and the rate of Al release is also apparently very small. Cell interaction with these surfaces was illustrated and the potential for loading the pores with bioactive materials discussed.

Following lunch, delegates were able to 'mix and match' between three parallel sessions. from an industry perspective of plasma sprayed coatings (R. Scott, Biomet-Merck) to bone fragility & its causes (P. Zioupos, Cranfield U.) and an introduction to the medical devices Faraday partnership (F. Smith, MDFP).

J. Franks (Brunel U.) described a room temperature fabrication route for the formation of diamond like carbon coatings with high substrate adherence. These were described as being hard and flexible and good for preventing thrombus formation. Finally, J. Elliott (Queen Mary), who has been described as one of the most notable pioneers in apatite structural chemistry, carefully described the key ionic packing arrangement of the apatite lattice and pointed out that most of the space is occupied by phosphate ions packed into a pseudo-HCP arrangement. He illustrated several ionic substitution possibilities and, in particular, carbonate substitution into phosphate and hydroxyl sites. He finished by indicating that apatites can still produce surprising results and described how his recent work has shown evidence of formate substitutions.

Further details of the next workshop will be announced in due course at www.cranfield-biomaterials.com.

K.D. Rogers