Inactivation of Staphylococcus aureus in calcium phosphate biomaterials via isostatic compression

High hydrostatic pressure is currently used as a sterilization technique in agroalimentary field. This study explores the potential use of high pressure for bacterial inactivation of bone substitute calcium phosphate materials. Staphylococcus aureus strain incorporated in calcium phosphate powder was subjected to isostatic compression. Several parameters of compression were tested: application of pressure, time of plateau, number of compressions, and waiting time between two compressions. The results showed that the efficacy of compression increased with applied pressure and that time of plateau did not play an important role. The number of compressions influenced the efficiency of the technique and it was necessary to allow ample time between two compressions for bacteria to sufficiently multiply. The most effective protocol for preventing the growth of S. aureus in calcium phosphate involved two compressions of 5 minutes each at 140 MPa spaced at a 24-hour interval.