Conformational change of hydroxyapatite/gelatin nanocomposite by glutaraldehyde.

The hydroxyapatite (HAp)/gelatin (GEL) nanocomposite was prepared through the coprecipitation and then cross-linked by using glutaraldehyde (GA). From FT-IR measurement the spectral features for amide bands and phosphate bands were severely modified by the cross-linkage and the organic content increased with the degree of cross-linkage. From Transmission Electron Microscopy (TEM) and electron diffraction analyses we could confirm the preferentially directional growth of needle-like HAp particles, which were embedded in GEL by the mineralization. Also we could observe worm-like stria patterns of contrast, which were revealed by the mineralization on the individual GEL fibrils. Moiré images were observed in a highly cross-linked HAp/GEL nanocomposite sample and we think the cross-linkage induced the assembly of unordered individual fibrils along the preferential direction.