Effects of gallic acid on the nanocrystalline hydroxyapatite formation using the neutralization process

Abstract

Background: Hydroxyapatite nanoparticles (nHAp) have excellent properties, such as biocompatibility and osteoconductivity, which are critical for bone reconstruction. However, they remain inactive against pathogenic bacteria that can grow in defected bone tissue, and their use in some patients may result in some undesirable inflammatory reactions. Gallic acid (GA) is known for its specific anti-inflammatory and antibacterial properties. Coupling these characteristics with nHAp is of great interest. Methods: The present study investigated the preparation of nHAp in the presence of various proportions of GA (0, 0.6, 2.5, and 5 mMol) using the neutralization method at room temperature. The effect of GA on the crystallinity, chemical composition, and surface specific area (SSA) of the prepared nHAp-GA composites was also studied. Results: X-ray diffraction and Brunauer-Emmett-Teller (BET) analysis revealed that the precipitation of nHAp in the presence of a low fraction of GA induced the formation of nHAp with low crystallinity and high SSA (142 m2/g), while GA at high concentration limited nHAp growth and favored the ACP formation with low SSA (32 m2/g). X-ray photoelectron spectroscopy (XPS) indicated that GA is adsorbed on the nHAp surface and controlled its growth. Conclusion: Overall, the prepared nHAp/Ga composites presented chemical and structural characteristics close to those of natural bone that make them a good candidate for bone tissue regeneration.

Keywords

• Hydroxyapatite nanoparticles
• Gallic Acid, Adsorption-desorption isotherms
• XPS surface analysis
• Bone tissue regeneration