Nucleation and growth of bone-like apatite on surfaces of metals, ceramics and polymers in simulated body fluids

Abstract

The biomimetic approach of mineralization in vitro is adopted to investigate systematically the nucleation and growth of bone-like apatite on the surface of biomaterials such as bioceramics, metals and polymers, and those chemically surface-treated. The simulated environment is kept isothermic at the human body temperature of 36.5C with three kinds of simulated physiological fluids. The experimental results show that (1) inherent properties of biomaterials determine their bioactivity and the different crystalline structure of same materials results in the difference in bioactivity; (2) the bioactivity can effectively be improved by the surface treatment of biomaterials via chemical methods and by the addition of bioactive particles in a polymer matrix; (3) the bone-like apatite, nucleated and grown in the simulated body fluid with the same ion concentrations to that of the human plasma, possesses the same composition, structure and morphology despite of matrixes; (4) the difference in bioactivity with biomaterials is indicated by the different time for bone-like apatite to nucleate and to grow on their surfaces.