Biomimetic configurational arrays of hydroxyapatite nanocrystals on bio-organics

Biomimetic configurational arrays of hydroxyapatite (HAp) nanocrystals on several bio-organics, collagen (Col), chondroitin sulfate (ChS), and their mixture, were comparatively studied. The nanocomposites of HAp/Col, HAp/ChS, and HAp/Col/ChS were synthesized through a precipitation method with calcium hydroxide suspension and phosphoric acid solution containing Col, ChS, and their mixture, respectively. The (0 0 2) diffraction of the synthesized HAp crystals on a Col fiber showed an around 60° arching angle, while that on a ChS fiber showed just around 10°. The same configurational arrays of HAp crystals could also be obtained on the mixture of Col and ChS fibers. The different electron diffraction patterns of the HAp crystals on the Col and ChS fibers were explained by the different macromolecular configurations of the Col and ChS fibrils which compose their fibers. The results may be applicable to develop a bone substitute which mimics the peculiar configurational arrays of HAp crystals found in bone and their detailed organic composition.