Preparation of calcium phosphate/carboxymethylcellulose-based bone cements

In this study, novel bone substitutes were prepared based on a powder phase composed of tetracalcium phosphate, dicalcium phosphate dihydrate and calcium sulfate dihydrate and a liquid phase composed of carboxymethylcellulose (CMC), citric acid and gelatin. Samples were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD), mechanical testing, swelling-degradation studies and cell culture studies. FTIR results showed that CMC and calcium phosphate interacted through electrostatic forces and hydrogen bonding. After incubation in phosphate-buffered saline for 28 days, hydroxyapatite formation was distinguished by way of SEM and XRD analysis. Mechanical test results revealed that the compressive modulus was up to 1.050 +/- 0.071 GPa and that the compressive strength was up to 1.680 +/- 0.023 MPa. Cell culture studies indicated that the samples were biocompatible and may be suitable for replacing cancellous bone and supporting new bone formation.