On the use of nanoliposomes as soft templates for controlled nucleation and growth of hydroxyapatite nanocrystals under hydrothermal conditions

Calcium phosphates are biocompatible materials with the composition closest in similarity to the mineral phase of bone. Among them, hydroxyapatite (HA) is shown to be the most promising bioactive compound widely used in bone tissue engineering applications. It has been shown that the preparation of HA with controlled morphology and size distribution may be beneficial to therapy of bone disease. In this study, a new method was developed for the synthesis of nano-HA particles in which nanoliposomes were used as nucleation sites for growth of HA crystals. Phase composition, morphology, particle size and the molecular structure of sediments were studied using X-ray diffraction techniques (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). The results showed that nanoliposomes could act as carriers for the crystal growth of nano-HA particles. The powder produced from liposome encapsulation contained hexagonal bipyramidal structures of HA with nanometer dimensions, spherical shapes, dense morphologies and a mean size of about 60 nm. Further investigation of the bioactivity and biocompatibility of this new class of biomaterials is being performed.