Biomimetic fabrication of nanoengineered hydroxyapatite/polyelectrolyte composite shell

Biomimetic synthesis of biocompatible ceramic material, calcium hydroxyapatite Ca-10(PO4)(6)(OH)(2), was performed exclusively inside poly(allylamine)/poly(styrene sulfonate) polyelectrolyte capsules of micron scale. Calcium hydroxyapatite mainly forms on the inner side of the capsule shell resulting in empty composite hydroxyapatite spheres of micron size. Depending on the amount of precipitated hydroxyapatite, the thickness of the shell of composite spheres can be varied between 25 and 150 nm. Hydroxyapatite spheres were characterized by TEM, SEM, and WAXS techniques. The influence of the inner capsule composition on the characteristics of the resulting hydroxyapatite material was also investigated.