Dual setting brushite-gelatin cement with increased ductility and sustained drug release

A novel dual setting brushite-gelatin cement was achieved by genip ininitiated cross-linking of gelatin during cement setting. Although the combination of an inorganic and organic phase resulted in a decrease of the compressive strength from about 10 MPa without polymeric phase to 3-6-MPa for gelatin modified composites, an increase in elastic properties due to the gelatin hydrogel with a concentration of 10.0 w/v% was achieved. For a powder-to-liquid ratio of 2.5 g*mL^-1, a shift of initial maximum stress value during compression testing was observed up to 5% deformation and tested samples showed a pseudo-ductile fracture behavior. The obtained composites of the different formulations were characterized regarding phase composition, porosity as well as drug loading capacity with rifampicin and vancomycin. For the latter, a sustained and prolonged release was realized with a drug release profile according to the Higuchi model and a release exponent of n = 0.5 for the formulation with a PLR of 2.5 g*mL^-1 and an incorporation of 10.0 w/v% gelatin.