Grafting of nanospherical PMMA brushes on cross-linked PMMA nanospheres for addition in two-solution bone cements

Poly(methyl methacrylate) (PMMA) brushes were grafted to the surface of cross-linked PMMA nanospheres for use as the polymer phase in the preparation of the two-solution bone cement. PMMA chains grafted on the core of the cross-linked PMMA nanostructures were hypothesized to impart viscosity to the cement mixture, while providing entanglements with the matrix chains formed during cement cure. The first goal of this study was to develop a novel synthetic strategy to decorate the surface of nanoparticles with functional groups that allowed for grafting of PMMA brushes via radical polymerization. The grafting reactions were performed at specific combinations of monomer and initiator to produce a range of molecular weights adequate for the preparation of bone cements. The second goal was to investigate the ability of this novel methodology to produce high graft densities on the core surface from the analysis of the hydrodynamic properties of brushes. The synthetic pathway discussed enabled the synthesis of brushes with high graft densities and molecular weights tuned to provide optimal viscosities for preparation of brush-containing two-solution bone cements.