Development of highly functionalized ceramic biomaterials

Abstract

Ceramic biomaterials have been used clinically for repairing bony defects due to their biological affinity to living bone. Among ceramic biomaterials, bioactive ceramics directly bond to living bone. The bonding mechanism of bioactive ceramics to living bone provides a unique strategy in the development of novel biomaterials with high functionality. The mechanism of bone-bonding has been clarified through observation of interfaces between artificial materials and living bones as well as investigation of structural changes of the materials in solutions mimicking in vivo conditions. A simulated body fluid (SBF) that has similar concentrations of inorganic ions has been used to estimate surface structural changes of implanted materials in bony defects. Bone-like apatite deposition on the surface of implants is an important event to achieve bone-bonding with bioactive ceramics. Thus, it is important to control the reaction of such materials with body fluid during the development of novel biomaterials. Based on a fundamental understanding of the reactions of ceramic materials in SBF, novel types of biomaterials have been designed, such as surface-modified titanium metal, organic–inorganic hybrids, biomimetic composites, bioabsorbable materials, and calcium phosphates with designed morphology. In this review, the development of bioactive materials is described through a fundamental understanding of the calcification mechanisms of bioactive ceramics in SBF.