Cross-linkage of hydroxyapatite/gelatin nanocomposite using imide-based zero-length cross-linker

Hydroxyapatite [HAp]/Gelatin [GEL] nanocomposite was prepared at 37 and 48 °C through coprecipitation process. The HAp/GEL nanocomposite slurries were cross-linked by imide-based zero-length cross-linking agent such as N-(3-dimethylaminopropyl)-N′-ethylcarbodiimide (EDC) and N-hydroxysuccinimide (NHS). The chemical bond formation and microstructure in HAp/GEL nanocomposite was investigated as a function of cross-linking agents and temperature. The single addition of EDC into the composite slurries resulted in a tougher microstructure in both samples prepared at 37 and 48 °C. However, in the case of the simultaneous addition of EDC and NHS the sample prepared at 48 °C showed a coarse microstructure. These results were consistent with the fact that the chemical reactivity of NHS is degraded at 48 °C whereas the reactivity of EDC increases up to 80 °C.