Self-assembly phenomenon of hydroxyapatite nanocrystals on chondroitin sulfate.

Self-assembly phenomenon of hydroxyapatite (HAp) nanocrystals on chondroitin sulfate (ChS) templates was investigated. A HAp/ChS hybrid was synthesized through a precipitation method with a calcium hydroxide suspension and phosphoric acid solution containing the ChS. The preferential alignment of the crystallographic c-axis of the HAp crystals parallel to the long axis direction of the ChS templates was observed to occur with the chemical interactions between the HAp crystals and the functional groups of the ChS. This phenomenon was interpreted by the crystallochemical specific nucleation and growth of the HAp crystals regulated by the pre-organized functional groups of the ChS template. Practical implication may involve a biomimetic artificial bone or cartilage can be made through a precipitation method with suitable bio-organics.