title: Characterization of calcium phosphate cements modified by addition of amorphous calcium phosphate.
abstract: In this study the influence of amorphous calcium phosphate (ACP) on the setting of, and the formed apatite crystallite size in, a calcium phosphate cement (CPC) based on alpha-tricalcium phosphate (alpha-TCP) or tetracalcium phosphate (TTCP)/monocalcium phosphate monohydrate (MCPM) was investigated. Setting times at 22 degrees C were measured in air atmosphere; those at 37 degrees C were measured at 100% relative humidity. The phase composition of the set cements was investigated after 1 week using X-ray diffractometry and infrared spectroscopy and the morphology was investigated using scanning electron microscopy. The compressive strength (CS) of the set CPCs was measured after 1 day. Viability of MC3T3-E1 cells on the CPCs was analyzed after 7, 14 and 21 days of incubation using the CellTiter 96 Aqueous Non-Radioactive Cell Proliferation Assay. The alpha-TCP-based cement exhibited long setting times, a high CS and was converted to a calcium-deficient hydroxyapatite (CDHAp). The TTCP/MCPM-based CPC was only partly converted to CDHAp, produced acceptable setting times and had a low CS. Addition of ACP to these two CPCs resulted in cements that exhibited good setting times, CS suitable for non-load-bearing applications and a full conversion to nanocrystalline CDHAp. Moreover, the ACP containing CPCs demonstrated good cell viability, making them suitable candidates for bone substitute materials.
authors: Department of Basic Medical Science - Biomaterials Group, Ghent University, De Pintelaan 185, Building B, 4th Floor, Ghent, Belgium. nastasja.vandenvreken@ugent.be
authors: Natasja M F
authors: NM
authors: Van den Vreken
authors: Ilse Y
authors: IY
authors: Pieters
authors: Heidi A
authors: HA
authors: Declercq
authors: Maria J
authors: MJ
authors: Cornelissen
authors: Ronald M H
authors: RM
authors: Verbeeck
mesh_terms: D016475:3T3 Cells; D000818:Animals; D001843:Bone Cements; D002130:Calcium Phosphates; D018360:Crystallography, X-Ray; D003470:Culture Media; D006863:Hydrogen-Ion Concentration; D051379:Mice; D008855:Microscopy, Electron, Scanning; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D001843:Bone Cements; D002130:Calcium Phosphates; D003470:Culture Media; C020243:calcium phosphate