Thermal and ultrasonic influence in the formation of nanometer scale hydroxyapatite bio-ceramic

Abstract

Hydroxyapatite (HAP) is a widely used biocompatible ceramic in many biomedical applications and devices. Currently nanometer-scale forms of HAP are being intensely investigated due to their close similarity to the inorganic mineral component of the natural bone matrix. In this study nano-HAP was prepared via a wet precipitation method using Ca(NO 3 ) 2 and KH 2 PO 4 as the main reactants and NH 4 OH as the precipitator under ultrasonic irradiation. The Ca/P ratio was set at 1.67 and the pH was maintained at 9 during the synthesis process. The influence of the thermal treatment was investigated by using two thermal treatment processes to produce ultrafine nano-HAP powders. In the first heat treatment, a conventional radiant tube furnace was used to produce nano-particles with an average size of approximately 30 nm in diameter, while the second thermal treatment used a microwave-based technique to produce particles with an average diameter of 36 nm. The crystalline structure and morphology of all nanoparticle powders produced were investigated using X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy (FT-IR). Both thermal techniques effectively produced ultrafine powders with similar crystalline structure, morphology and particle sizes.

Synthesis of a Hydroxyapatite Nanopowder via Ultrasound Irradiation from Calcium Hydroxide Powders for Potential Biomedical Applications

“…Both Figure 4 (b) and (c) reveal the powder sample synthesized at 400 W is highly agglomerated. The particle morphology seen in this study is similar to morphologies previously reported in the literature [22][23][24][25]. Particle size analysis based on TEM and FESEM images for the 400 W power setting reveals a narrow particle size distribution.…”

“…The positive results achieved in these clinical applications has encouraged further research into HAP and its potential use in a variety of new tissue regeneration and tissue engineering applications [16,17]. To date several ceramic processing techniques have been used to synthesize HAP such as wet precipitation, sol-gel, hydrothermal and ultrasonic [18][19][20][21][22]. However, there is a current need to develop more efficient processing techniques that have the potential to deliver large quantities of HAP nanopowders for future biomedical applications.…”

Current and future applications of nanotechnology in plastic and reconstructive surgery

“…Given the nanoscale architecture of native bone crystals, manufacturing HA on a nanoscale would theoretically improve its utility. Poinern et al [30] investigated the effects of thermal and ultrasonic techniques for the development of these particles and demonstrated that either technique can generate particles of similar consistency. Abd El-Fattah et al [31] histomorphometrically analyzed the tissue by growth and scaffold degradation in three groups of rats with identical bone defects: one filled with mirco-HA, one with nano-HA and one control group without filler.…”

Chemical Immersion Coatings to Improve Biological Degradability of Magnesium Substrates for Potential Orthopaedic Applications

“…The use of HAP coatings has a number of advantages besides improving the corrosion resistance of Mg and Mg based alloys in the physiological environment. HAP is a major inorganic component found in natural bone tissues, therefore using HAP as a biological coating on Mg offers a number of attractive properties such as its good biocompatibility and bioactivity properties with respect to bone cells and other body tissues [67]. Other desirable properties include slow biodegradability in situ and its ability to promote osteoconductivity and osteoinductivity, which can accelerate the in-growth of surrounding tissues [68][69][70].…”