Natural bioceramics: from coral to bone and beyond

Recent advances in the production and use of natural bioceramics for applications in hard and soft tissue replacement are discussed. The synthesis of complex inorganic forms, which are based on natural structures that can mimic natural scaffold, upon which the cells are seeded, offers an exciting range of avenues for the construction of a new generation bone analogs for tissue engineering. The use of natural and synthetic calcium phosphate bioceramics as bone grafts in orthopaedics and dentistry is considered. Issues affecting the use of different materials in vivo are outlined, of particular importance are osteoconductivity (ability to support tissue ingrowth and bone formation) and osteogenicity (formation of bone from cells within a bone graft). A variety of other natural alternatives including sol-gel coated coralline apatite are evaluated, and other key success factors (strength, longevity and stability) are reviewed. Several treatments for improving performance are outlined, and speculation on future advances, including combination of traditional bioceramic implants with more recent advances in stem cell research is made. (C) 2003 Elsevier Ltd. All rights reserved.