Synthesis of carbonated hydroxyapatite nanospheres through nanoemulsion

Abstract

This study investigated the nanoemulsion technique as a means to synthesize carbonated hydroxyapatite (CHAp) nanospheres which could be used to produce composite tissue engineering scaffolds. CHAp nanospheres were successfully synthesized by mixing an acetone solution of Ca(NO(3))(2).4H(2)O with an aqueous solution of (NH(4))(2)HPO(4) and NH(4)HCO(3). Four reaction temperatures, namely, 4, 25, 37 and 55 degrees C, were investigated and no surfactant was added in all nanoemulsion processes. Wet slurries of CHAp from the nanoemulsions were freeze-dried to obtain dry powders. X-ray diffraction (XRD) results showed that the as-synthesized CHAp nanoparticles were mainly in an amorphous state. After calcination at 900 degrees C, the apatite became well crystallized. Fourier transform infrared (FTIR) spectroscopy showed that the CHAp was B-type substitution. Both scanning electron microscopy (SEM) and transmission electron microscopy (TEM) revealed that the CHAp particles were spherical in shape and that their sizes were in the nanometer range. The successful synthesis of CHAp nanospheres is a critical step forward in our efforts to fabricate bone tissue engineering scaffolds using the selective laser sintering technology.

PHBV/PLLA-based composite scaffolds containing nano-sized hydroxyapatite particles for bone tissue engineering

“…(The SAD pattern was obtained using a transmission electron microscope.) As with the previous study [18], the particle size of the HA powders was found to be in the range of 20-30 nm. The nanoparticles were basically HA crystallites precipitated from the chemical reaction in the nanoemulsion process.…”

“…All chemicals were of analytical grade and were also used in the as-received state. The nano-sized HA used for composite scaffolds was produced in-house through a nanoemulsion process [18]. Figure 1 shows the nanosized HA together with a selective area diffraction (SAD) pattern of the particles.…”

Characterization, drug loading and antibacterial activity of nanohydroxyapatite/polycaprolactone (nHA/PCL) electrospun membrane

“…The nHA was synthesized in-house using a nanoemulsion process described elsewhere (Zhou et al 2008). A solution of Ca(NO 3 ) 2 Á4H 2 O in acetone was mixed for 30 s with a solution of (NH 4 ) 2 HPO 4 in distilled water at pH 11.…”

Selective Laser Sintered Poly(L-Lactide)/Carbonated Hydroxyapatite Nanocomposite Scaffolds: A Bottom-up Approach

“…In this study, three major issues were addressed. Firstly, the nanoemulsion method was applied to synthesize CHAp nanospheres (~20 nm) as the osteoconductive filler for building the nanocomposite scaffolds (Zhou, Wang et al 2008). Secondly, PLLA microspheres and PLLA/CHAp nanocomposite microspheres (~5-30 µm) were prepared by the oil-in-water and solid-in-oil-in-water emulsion solvent evaporation procedures respectively (Zhou, Wang et al 2007).…”