LifeLongJoints

We work in a project called LifeLongJoints, which aims at prolonging the lifetime of joint implants by coating traditionally metallic parts with silicon nitride. Silicon nitride is a ceramic material that has the potential to reduce the generation of wear debris as well as the release of metal ions. In addition silicon nitride is soluble in water which could mean that the generated wear particles slowly dissolve in the body, thus minimizing the adverse immune response otherwise often encountered towards wear particles. This adverse immune response is believed to be one of the main limiting factors of the implant lifetime.

Charlotte: My research revolves around alloying the coating with biocompatible elements such as niobium, carbon and iron to alter the adhesion and dissolution rate of the coating. To do this I deposit coatings with compositional gradients for an efficient screening, using a combinatorial approach. The mechanical properties, surface properties, cell adhesion, dissolution and coating adhesion are then evaluated.

Osteoprogenitor cells (MC3T3) on silicon nitride based coatings, obtained in a fluorescent microscope. The cells are adhering as well as differentiating indicating the material may be suitable for the application.

Luimar: My research is related to characterization of Silicon Nitride coatings deposited on CoCrMo substrates (2D and 3D) by High Power Impulse Magnetron Sputtering for hip joint applications. The coatings has different depositing parameters as composition (Si, N, O and C %at.), bias voltage, cathode power, presence of CrN interlayer and fold rotation. Using cell studies, adhesion test, dissolution test, reciprocal and multidirectional wear test, optical interferometer also electron microscopy those coatings can be evaluated in terms of biocompatibility, coating strength, wear properties and morphology.

Focus Ion Beam cross-section of Silicon Nitride (SiNx) and CrN interlayer, deposited using negative bias voltage of 900V and 1 fold rotation on CoCrMo disc. 

Contact:

Charlotte Skjöldebrand (charlotte.skjoldebrand@angstrom.uu.se)

Luimar Correa Filho (luimar.filho@angstrom.uu.se)