The Next Generation of Bone Cements: The Use of Magnetic Calcium Phosphate Particles to Enhance Bone Cement Properties

Despite the fact that bone cement has been utilized since the 1950's, its polymerization, biocompatibility, and ultimate mechanical properties are still considered lacking, which contributes to implant loosening and failure. In this experiment, specialized magnetic calcium phosphate nanoparticles (MCaP) bound with chitosan are used as a filler material within a methyl methacrylate-based bone cement. It was hypothesized that these particles could be used to control the bone cement's polymerization rate through inductive heating via an oscillating magnetic field. Preliminary testing varied N-N-dimethyl-p-toluidine (NDMT) from 0.25-2.00% and 5-30% weight/volume (w/v) MCaP with 0.8% benzoyl peroxide. Optimal polymerization properties were observed at 10% MCaP with 0.5% NDMT; however samples exhibited significant gas evolution, reducing their mechanical properties. Further researched showed that 10% MCaP in the absence of NDMT was capable of inducing polymerization on a reasonable time scale and showed significantly reduced porosity from gas evolution. Though more quantification and testing remains to be done, this research presents promising evolution in the formulation and use of bone cements.