BONE MIMETICS - A COMPOSITE OF HYDROXYAPATITE AND CALCIUM DODECYLPHOSPHATE LAMELLAR PHASE

The synthesis of composites based upon mineral and organic constituent s is of importance for the development of materials for biomedical app lications, such as bone replacement, augmentation and repair. Herein w e describe a biologically inspired inorganic materials chemistry appro ach to bone mimetics. The synthetic strategy is based upon the surfact ant-templated cooperative assembly of a composite that is composed of a calcium dodecylphosphate lamellar phase (CaDDP) and a calcium hydrox yphosphate (CaP) mineral phase. The measured properties of the chemica lly formed composite suggest that it is distinct from simple physical mixtures of the CaDDP and CaP components. A key difference is the gene ration of biologically important hydrogenphosphate located at the inte rface between the CaDDP and CaP phases only in the chemically formed c omposite. The synthesis of the composite is considered to involve the synergistic interaction of CaDDP and CaP, possibly aided by interfacia l complementarity of charge and geometry. CaDDP is chemically stable a nd non-toxic, rendering the composite potentially useful for biomedica l applications.