Tóm tắt

The friction and wear properties of silica/poly(tetrahydrofuran)/poly(ε-caprolactone) (SiO2/PTHF/PCL- rndiCOOH) hybrid materials that are proposed as cartilage tissue engineering materials were investigated against rnliving articular cartilage. A testing rig was designed to allow testing against fresh bovine cartilage. The friction rnforce and wear were compared for five compositions of the hybrid biomaterial articulating against freshly rnharvested bovine cartilage in diluted bovine calf serum. Under a non-migrating contact, the friction force in-creased and hence shear force applied to the opposing articular cartilage also increased, resulting in minor rndamage to the cartilage surface. This worse case testing scenario was used to discriminate between material rnformulations and revealed the increase in friction and damaged area was lowest for the hybrid containing the rnmost silica. Further friction and wear tests on one hybrid formulation with an elastic modulus closest to that of rncartilage were then conducted in a custom incubator system. This demonstrated that over a five day period the rnfriction force, cell viability and glucosaminoglycan (GAG) release into the lubricant were similar between a rncartilage-cartilage interface and the hybrid-cartilage interface, supporting the use of these materials for cartilage rnrepair. These results demonstrate how tribology testing can play a part in the development of new materials for rnchondral tissue engineering. rnStatement of significance: Designing materials that maintain the low friction and wear of articular cartilage whilst rnsupporting the growth of new tissue is critical if further damage is to be avoided during repair of cartilage rndefects. This work examines the tribological performance of a SiO2/PTHF/PCL-diCOOH hybrid material and rndemonstrates a testing protocol that could be applied to any proposed material for cartilage regeneration. rnTribological tests demonstrated that changing the hybrid composition decreased friction and reduced damage to rnthe cartilage counterface. This study demonstrates how tribological testing can be integrated into the design rnprocess to produce materials with a higher chance of clinical success.