SEPTEMBER 11, 2008 -- The University of Leeds (Leeds, U.K.) has found nanoparticle tracking analysis (NTA) useful for measuring debris generated by wear in orthopaedic implants.
Dr. Joanne Tipper of the Institute of Molecular and Cellular Biology studies nanoparticle sized polymer debris, specifically polyethylene generated first in vitro (to prove its presence) and then in vivo (from tissue from around failed hip replacements). Her objective has been first to characterize/size the particles and then to consider their bioactivity and effect on cell responses.
Dr. Tipper has made measurements on different materials used for implants (metal-metal, ceramic-ceramic and polymer-polymer). She has had good results on model metal and ceramic particle systems. The metal nanoparticle debris are typically in the range of 20-80nm which is particularly suited to NTA when compared to light scattering methods. The results, produced by NanoSight Ltd's (Salisbury, U.K.) NTA system, compare extremely well with high resolution FEG-SEM, and these particles compare well with clinically generated wear debris.
NTA has proven easy to use, according to Dr. Tipper: It requires minimal sample preparation time compared to SEM and provides results in minutes. When studying polymers, NTA produced excellent results for polyethylene particles in the 100-800nm range, again when compared to FEG-SEM.
NanoSight's chief technical officer and founder, Dr. Bob Carr, says this application is typical of why nanoparticle sizing is becoming critical in many processes. "Understanding biocompatibility and nanotoxicology effects have contributed to the demand for our instrumentation where researchers want to increase their knowledge of materials performance on the nanoscale."