Synthesis and characterization of nanocrystalline hydroxyapatite gel and its application as scaffold aggregation

Abstract

The sol-gel process is a technique used to synthesize materials from colloidal suspensions and, therefore, is suitable for preparing materials in the nanoscale. In this work hydroxyapatite was used due to its known properties in tissue engineering. Hydroxyapatite Ca 10 (PO 4 ) 6 (OH) 2 is a bioactive ceramic which is found in the mineral phase of bone tissue and is known for its great potential in tissue engineering applications. For this reason, this material can be applied as particle aggregates on ceramic slurry, coating or film on materials with a poorer biological response than hydroxyapatite. In this work, hydroxyapatite gel was obtained by the sol-gel process and applied as nanoparticle aggregation in the mixture of hydroxyapatite and tricalcium phosphate to form a ceramic slurry. This process is the polymer foam replication technique used to produce scaffolds, which are used in tissue engineering. For HA gel characterization it was used enviromental scanning electron microscopy (ESEM), transmission electron microscopy (TEM), electron energy loss spectroscopy (EELS), scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray fluorescence (XRF). The crystallite size was calculated from XRD data using the Scherrer equation. The nanoparticles size before firing was approximately 5nm. The crystallite size calculated after calcination was approximately 63 nm. The EELS results showed that calcium phosphate was obtained before firing. After HA gel calcination at 500 °C the XRD results showed hydroxyapatite with a small content of beta-TCP. The scaffolds obtained by polymer foam replication technique showed a morphology with adequate porosity for tissue engineering.

Calcium hydroxyapatite nanoparticles as a reinforcement filler in dental resin nanocomposite

“…Accordingly, the synergism between the adjacent layers played an important role in determining the frictional behavior [ 59 ]. Furthermore, HA particles exhibited weak Vander Waal forces and they were extended for just a few nanometers; therefore, CC and WC followed the exfoliation mechanism [ 56 , 60 ]. In this mechanism, under the effect of shear force, two adjacent layers were easily exfoliated, which led to the sliding movement of these layers, followed by a decrease in frictional and wear value.…”

Ionic Liquid-Assisted Hydrothermal Synthesis of a Biocompatible Filler for Photo-Curable Dental Composite: From Theory to Experiment

“…Materials with higher crystallinity (fewer crystal defects) result in lower photon absorption in the UV-Vis region, which is an important parameter for light curable dental composites, leading to effective absorption of photo-initiators. The average crystallite size of the products was estimated using the Scherrer formula and applied to the main XRD peaks [52,53,54], which reveals that the sample obtained via the ILH route (about 35–42 nm) has a lower average crystallite size compared to the sample prepared using the CH method (about 68–75 nm), which is caused via the role of IL in controlling the growth process.…”

Effect of pH and Ageing Time in the Preparation of A Ceramic Drug Delivery Carrier

“…With a decrease in Ca:P molar ratio, crystallinity, crystal size and the solubility of precipitated hydroxyapatite will increase 4 . Hydroxyapatite is prepared by various preparatory techniques and from various starting materials [5][6][7][8][9] . The precipitation process is the most reported method for preparing hydroxyapatite powder, which is simple, low cost and suitable for large scale production.…”