Adding ceramic particles to the polymers and blasting the composite with gamma-radiation could toughen up plastic joints in joint replacement surgeries and make them strong enough to last for years, says a new research.
Maoquan Xue of the Changzhou Institute of Light Industry Technology, has investigated the effect of adding ceramic particles and fibers to two experimental materials for coating prosthetic joints, UHMWPE (ultra-high-molecular-weight polyethylene) and PEEK (polyether ether ketone).
Alone neither UHMWPE nor PEEK is suitable as a prosthetic cartilage material because both crack and fracture with the kind of everyday stresses that a hip or knee joint would exert on them, and the long polymer chains within the material can readily propagate applied forces causing tiny fractures to grow quickly and the material to fail.
Xue then demonstrated that by adding ceramic particles to the polymers and blasting the composite with a short burst of gamma-radiation, it is possible to break the main polymer chains without disrupting the overall structure of the artificial cartilage.
As a result of the gamma burst, there is no way for microscopic fractures to be propagated throughout the material because there are no long stretches of polymer to carry the force from one point to the next and the resulting treated material is much tougher than the polymer alone, and will not produce the problematic debris within a joint that might otherwise lead to inflammation and pain for the patient.
Xue adds that the treated composite materials might also be more biocompatible and less likely to be rejected by the patient's immune system on implantation.
The study has been published in the current issue of the International Journal of Biomedical Engineering and Technology.