Lecithin-based wet chemical precipitation of hydroxyapatite nanoparticles

Abstract

Hydroxyapatite Ca₁₀(PO₄)₆(OH)₂ nanoparticles have been successfully synthesized by the wet chemical precipitation method at 60 °C in the presence of biocompatible natural surfactant-lecithin. The composition and morphology of nanoparticles of hydroxyapatite synthesized with lecithin (nHAp-PC) was studied by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Size distribution for nanoparticles was measured by nanoparticle tracking analysis in NanoSight system. We discuss in details influence of lecithin concentration in reaction system on nHAp-PC morphology, as well as on size distributions and suspendability of nanoparticles. Product exhibits crystalline structure and chemical composition of hydroxyapatite, with visible traces of lecithin. Difference in surfactant amounts results in changes in particles morphology and their average size.

Keywords: Hydroxyapatite; Lecithin; Nanoparticles; Synthesis; Wet chemical precipitation.

Fig. 1

XRD patterns of commercially available hydroxyapatite powder (nHAp) and hydroxyapatite nanoparticles (nHAp-PC) synthesized with 3.00 % w/w lecithin

Fig. 2

FTIR spectra of lecithin-based (3.00 % w/w) wet chemical precipitation synthesized hydroxyapatite nanoparticles (nHAp-PC), commercially sourced hydroxyapatite nanoparticles (nHAp), and pure soybean lecithin

Fig. 3

SEM images of lecithin-based wet chemical precipitation synthesized hydroxyapatite nanoparticles: a 0.30 % w/w lecithin, b 0.75 % w/w lecithin, c 1.50 % w/w lecithin, d 3.00 % w/w lecithin, e 9.00 % w/w lecithin, and f enlargement of 9.00 % w/w lecithin; note the difference in scale

Fig. 4

NanoSight size distribution, dominant particle morphology, and average particle size of lecithin-based wet chemical precipitation synthesized hydroxyapatite nanoparticles: a 0.30 % w/w lecithin, b 0.75 % w/w lecithin, c 1.50 % w/w lecithin, d 3.00 % w/w lecithin, e 9.00 % w/w lecithin