Hydroxyapatite from Natural Sources for Medical Applications

Abstract

The aim of this work is to study the physical-chemical, mechanical, and biocompatible properties of hydroxyapatite obtained by hydrothermal synthesis, at relatively low temperatures and high pressures, starting from natural sources (Rapana whelk shells), knowing that these properties influence the behavior of nanostructured materials in cells or tissues. Thus, hydroxyapatite nanopowders were characterized by chemical analysis, Fourier-transform infrared spectroscopy (FT-IR), dynamic light scattering (DLS), scanning electron microscopy (SEM), and X-ray diffraction (XRD). In vitro studies on osteoblast cell lines (cytotoxicity and cell proliferation), as well as preliminary mechanical tests, have been performed. The results showed that the obtained powders have a crystallite size below 50 nm and particle size less than 100 nm, demonstrating that hydrothermal synthesis led to hydroxyapatite nanocrystalline powders, with a Ca:P ratio close to the stoichiometric ratio and a controlled morphology (spherical particle aggregates). The tensile strength of HAp samples sintered at 1100 °C/90 min varies between 37.6–39.1 N/mm2. HAp samples sintered at 1300 °C/120 min provide better results for the investigated mechanical properties. The coefficient of friction has an appropriate value for biomechanical applications. The results of cell viability showed that the cytotoxic effect is low for all tested samples. Better cell proliferation is observed for osteoblasts grown on square samples.

Surface Treatment of Mongolian Scots Pine Using Phosphate Precipitation for Better Performance of Compressive Strength and Fire Resistance

“…The XRD pattern of precipitation produced during the treatment is shown in Figure 3 . The precipitation mainly contains hydroxyapatite (HAP), calcium hydrogen phosphate (CaHPO 4 ·2H 2 O), calcium phosphate (Ca 3 (PO 4 ) 2 ), and sodium chloride (NaCl), which was in good agreement with previous studies [ 32 , 33 ]. The presence of NaCl is due to the residue of Na + and Cl − in treating solutions.…”

Study on the influence of scaffold morphology and structure on osteogenic performance

“…Presently, the most common strategy is to increase the biocompatibility of scaffolds by combining them with natural materials. It is generally believed that scaffolds constructed from natural materials such as hydroxyapatite, chitosan, and collagen ( Akilbekova et al, 2018 ) have good biocompatibility ( Cheburu et al, 2011 ; Park et al, 2019 ; Cursaru et al, 2022 ), but natural materials are difficult to process, unstable in material properties, and poor mechanical properties, and some materials such as collagen can have immunogenicity ( Shahab et al, 2012 ). Additionally, the scaffold structure can affect biocompatibility.…”

Characterization and Synthesis Hydroxyapatite from Scallop Mussel Shells Prepared by the Microwave-Assisted Precipitation Methods

“…The synthesis result of HAp from scallop mussel shells using the microwave method have a good result and can be applied for many things. Recently, HAp has also been studied for medical such as drug delivery, collagen stimulation, skin regeneration, sun protection in the pharmaceutical industry, water purification, wastewater treatment, and in other chemical, optical, and electronics industries, and has the potential to be anticancer drug [41,42]. From those studies, HAp can be used for various biomedical applications.…”