Fabrication of hollow hydroxyapatite particles assisted by small organic molecule and effect of microstructure on protein adsorption

Nanostructured hollow hydroxyapatite (HA) particles were fabricated under hydrothermal conditions with cyclohexane-1,2,3,4,5,6-hexacarboxylic acid (H6L) as the template, and their formation process was investigated. Without the assistance of H6L, the product consisted of ribbon-like HA crystals. With the introduction of H6L, the HA particles gradually changed from flower-like plate aggregates to microspheres. Nanostructured hollow HA particles were synthesized at 50 mM H6L. Based on transmission electron microscopy and infrared spectroscopy, a possible mechanism for the formation of hollow HA particles was suggested. Differences in HA microstructure resulted in significantly different protein adsorption patterns for bovine serum albumin and lysozyme, suggesting the influence of particle microstructure on adsorption properties. The method provides a simple and controllable route to synthesize HA with various hierarchical structures. (C) 2015 Elsevier Ltd. All rights reserved.