Effects of Gum Arabic on Properties of Collagen-hydroxyapatite Composite

In order to improve the interfacial bonding properties of collagen-hydroxyapatite (Col-HA) composite, gum Arabic was introduced in the system. Ca(NO(3))(2)center dot 4H20, (NH(4))(2)HPO(4), acid dissolved collagen, and gum Arabic were used as the raw materials to in situ prepare collagen-hydroxyapatite/gum Arabic (Col-HA/Gum A) composite. Crystallite phase, chemical composition, and micro-morphology of the composite were characterized by XRD, FT-IR, and SEM. The effects of gum Arabic on the structure and properties of the collagen-hydroxyapatite composite were analyzed. The results indicate that both the interface structure and the surface morphology of the collagen-hydroxyapatite composite are changed by the introduction of gum Arabic. With increasing the amount of gum Arabic in the system, the sizes of the crystal grain and the crystallinity of the Col-HA composite are decreased. Both the hydrophilic properties and the enzymatic degradation capacity in vitro of the composite are decreased significantly (P<0.01), whilst the mechanical properties of the composite are improved in a certain range. Complexes of protein-polysaccharide can be formed between the gum Arabic and the collagen or collagen-hydroxyapatite, and the gum Arabic can act as a cross-linking agent in the new composite.