Sonochemical preparation of hydroxyapatite nanoparticles stabilized by glycosaminoglycans

Stable hydroxyapatite (HAP) nanoparticles system was synthesized from Ca(H2PO4)2 aqueous solution and saturated Ca(OH)2 aqueous solution by an improved precipitation method. This method was reformed through using ultrasound irradiation as assistant technology due to its unique chemical reaction effects and adding glycosaminoglycans (GAGs) as regulation additive due to its strong interaction with HAP. The products were characterized by Malvern Zetasizer 3000HS Analysis system, TEM and ED. The size distribution and zeta potential of HAP nanoparticles were influenced by the concentration of GAGs. With the GAGs concentration of 0.35 g/L, the better excellent HAP nanoparticle system could be obtained with the number-averaged particle size of 22.2 nm in 84.5% area and 54.6 nm in 15.5% area between 18.1 nm and 117.4 nm and the zeta potential of −60.9 mV. In the presence of GAGs, the particle size and size distribution are little sensitive to the ultrasound irradiation (UI) time. With the increasing of UI time from 0.5 h to 3 h and 5 h, the particle size increased a little and the crystallinity was improved. GAGs inhibited HAP crystal growth and stabilized HAP nanoparticles. Based on the TEM observation and size distribution determination of HAP nanoparticles, the possible formation mechanism of HAP nanoparticles stabilized by GAGs under UI was discussed.