hydroxyapatite - polymer nanocomposites , which are nanoparticles / microparticles , methods for making them , and articles made from them are disclosed . these methods are capable of preparing nanocomposites exhibiting more homogeneous dispersion of nanoparticles than is seen using previous methods . such nanocomposites and articles are useful for a wide variety of applications , such as biological , medical , biochemical , biosensor , fuel cell , and aerospace applications .