Structural features of hydroxyapatite and carbonated apatite formed under the influence of ultrasound and microwave radiation and their effect on the bioactivity of the nanomaterials

Abstract

The samples of hydroxyapatite and carbonate substituted hydroxyapatite (CHA) were obtained under the influence of physical factors, namely ultrasound (US) and microwave (MW) radiations. The results of Fourier transform infrared spectroscopy and X-ray diffraction analysis have proved the formation of the calcium deficient hydroxyapatite and B-type CHA with the Ca/P ratio in the ranges 1.62-1.87. In vitro studies have showed the increased bioactivity of the samples, synthesized under the influence of physical factors as compared to the standard ones. The samples of both groups, synthesized under the influence of 600 W MW, have shown the greatest stability in biological environment. In vivo tests confirm that obtained under US and MW radiations hydroxyapatite-based biomaterials are biocompatible, non-toxic and exhibit osteoconductive properties. The usage of US and MW radiations can significantly shorten the time (up to 5-20 min) of obtaining of calcium deficient hydroxyapatite and B-type CHA in nanopowder form, close in structure and composition to the biological hydroxyapatite.

New Generation of Hybrid Materials Based on Gelatin and Bioactive Glass Particles for Bone Tissue Engineering

“…These peaks correspond to the 4 (P -O bending) and 3 (P -O stretching) PO4 3-vibrations respectively in apatite structure. The carbonate CO3 2-vibration is also present [33][34][35]. These peaks are characteristic of a hydroxyapatite structure.…”

Single-walled carbon nanotubes loaded hydroxyapatite–alginate beads with enhanced mechanical properties and sustained drug release ability

“…HA hydrogel was obtained using a wet chemical coprecipitation method under microwave (MW) influence (Stanislavov et al 2018). Briefly, for HA synthesis 50 mL of Ca(NO 3 ) 2 •4H 2 O (0.167 M) and 50 ml of (NH 4 ) 2 HPO 4 (0.1 M) were used.…”

“…The swelling was quantified by measuring the sample weight changes as a function of immersion time in the phosphate buffered saline (PBS). This was a water-based salt solution containing disodium hydrogen phosphate (10 mmol/L), sodium chloride (137 mmol/L), potassium chloride (2.7 mmol/L) and potassium dihydrogen phosphate (1.8 mmol/L) (Sukhodub et al 2018;Palasz et al 2008). The appropriate quantity of each component was dissolved in 1 L of distilled water to obtain the needed concentration.…”

“…Therefore, a hybrid material containing organic and inorganic constituents may be better suited for large variations of composites. Natural and synthetic polymers serve as a physical matrix for HA immobilization and are extensively used for constructing biomaterials due to their high biocompatibility and low toxicity (Sukhodub et al 2018). Bone regenerative medicine often uses proteins such as collagen, fibrin and polysaccharides such as alginate, chitosan, hyaluronic acid.…”

“…CNTs consist of one or several graphitic shells, wrapped into a cylindrical tube, and are divided into two groups: multiwalled (MWCNTs) and single-walled (SWCNTs) CNTs (Reich et al 2008). Recently (Sukhodub et al 2018), we investigated the mechanical properties of the HA-alginate composite containing 0.04% MWCNT + Fe and showed that the material is characterized by a high compressive strength (168 MPa) compared to a cortical bone.…”