FT-IR study for hydroxyapatite/collagen nanocomposite cross-linked by glutaraldehyde

FT-IR analysis was performed for the hydroxyapatite (HAp)/collagen (COL) nanocomposite cross-linked by glutaraldehyde (GA). The amide bands I, II and III from COL matrix, and phosphate and carbonate bands from HAp were identified. The amide B band arising from C–H stretching mode showed a sensitive conformation by the degree of cross-linking. The amide I band showed a complicate conformational change by the degree of cross-linking. The characteristic amide I band at 1685 cm−1, which is known as an aging parameter in the biological bone, did not show a monotonous tendency by the degree of cross-linking. The relative contents of the organics in the cross-linked HAp/COL nanocomposite were evaluated as an integration ratio between the amide I band at 1600–1700 cm−1 and PO43− band at 900–1200 cm−1. The increase of the organics content by the cross-linking is enabled by the further organization of Ca2+ ions of HAp crystals in HAp/COL nanocomposite. The complicate conformational behavior in the amide I, II and III bands seems to be affected by the cross-linking induced directional arrangement of HAp/COL nanocomposite fibrils.