Bone mimetics: a composite of hydroxyapatite and calcium dodecylphosphate lamellar phase

Abstract

The synthesis of composites based upon mineral and organic constituents is of importance for the development of materials for biomedical applications, such as bone replacement, augmentation and repair. Herein we describe a biologically inspired inorganic materials chemistry approach to bone mimetics. The synthetic strategy is based upon the surfactant-templated cooperative assembly of a composite that is composed of a calcium dodecylphosphate lamellar phase (CaDDP) and a calcium hydroxyphosphate (CaP) mineral phase. The measured properties of the chemically formed composite suggest that it is distinct from simple physical mixtures of the CaDDP and CaP components. A key difference is the generation of biologically important hydrogenphosphate located at the interface between the CaDDP and CaP phases only in the chemically formed composite. The synthesis of the composite is considered to involve the synergistic interaction of CaDDP and CaP, possibly aided by interfacial complementarity of charge and geometry. CaDDP is chemically stable and non-toxic, rendering the composite potentially useful for biomedical applications.

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