By: David G. Waugh and Jonathan Lawrence

Wolfson School of Mechanical and Manufacturing Engineering, Loughborough University, UK
Lincoln School of Engineering, University of Lincoln, UK

The need for biological implants grows year upon year and it has been realized that there is a drive within the biomedical industry for cheaper and easier to manufacture products. This could be met by the use of polymeric materials; however, it has been seen that polymeric materials can often fail clinically and be rejected by body due to the fact that the surface properties do not give rise to adequate cell growth. One way to counteract this is to treat the polymeric surfaces prior to the implantation such that they then have properties which enhance the cell response and ultimately reduce the failure/rejection rate. Many techniques have been developed for the surface treatment of polymeric materials; however, many only have the ability to modify one surface parameter at any one time and can have detrimental effects on the bulk properties. One promising and interesting method to carry out these surface treatments is that of the use of laser technology which can be applied to a number of different materials ranging from ceramics, to metals, to polymers. Lasers have the ability to change both the surface dimensions (roughness and surface pattern) and the surface chemistry simultaneously which can then lead to a change in the wettability characteristics. Wettability characteristics are those surface parameters which are directly linked to the wetting nature of materials; for instance, the contact angle is the angle the liquid droplet makes with the solid surface and the surface free energy is the energy associated with the solid surface giving rise to the contact angle observed. The wettability characteristics of a material have already been shown that they can be implemented to predict the adhesive nature of materials. As a result of this, many believe that wettability can be implemented as a tool to estimate the bioactive nature of materials. This would give a massive opportunity to the biological industry as it would allow those within the bio-implant field to have the ability to predict whether an implant will fail. Continue reading →