Hydroxyapatite Nanoparticles / Nanopowder

• CAS: 1306-06-5
• Catalog Number: ACM1306065-27
• Category: Nanoparticles & Nanopowders
• Molecular Weight: 502.31
• Molecular Formula: Ca5(PO4)3(OH);Ca5HO13P3
• Description: DryPowder; Liquid; OtherSolid; PelletsLargeCrystals
• Synonyms: Hydroxylapatite
• IUPAC Name: pentacalcium; hydroxide; triphosphate
• Canonical SMILES: [OH-].[O-]P(=O)([O-])[O-].[O-]P(=O)([O-])[O-].[O-]P(=O)([O-])[O-].[Ca+2].[Ca+2].[Ca+2].[Ca+2].[Ca+2]
• InChI: InChI=1S/5Ca.3H3O4P.H₂O/c;;;;;3*1-5(2,3)4;/h;;;;;3*(H3,1,2,3,4);1H2/q5*+2;;;;/p-10
• InChI Key: XYJRXVWERLGGKC-UHFFFAOYSA-D
• Melting Point: 1100 °C
• Solubility: Practically insol in water, even when freshly prepared
• Appearance: Crystalline powder
• Color/Form: Hexagonal needles arranged in rosettes;Finely divided, crystalline, nonstoichiometric material.
• Complexity: 36.8
• Covalently-Bonded Unit Count: 9
• EC Number: 235-330-6
• Exact Mass: 501.675955
• Formal Charge: 0
• Hazard Codes: Xi
• Hazard Statements: H315-H319-H335
• H-Bond Acceptor: 13
• H-Bond Donor: 1
• Heavy Atom Count: 21
• MDL Number: MFCD00010904
• Monoisotopic Mass: 501.675955
• Other Experimental: Decomposes above 1100 °C;Density: 3.1 to 3.2 /Apatite/
• Risk Codes: 36/37/38
• Rotatable Bond Count: 0
• Safety Description: 26
• UNII: 91D9GV0Z28

Case Study

Effects of Hydroxyapatite Nanoparticles/Nanopowder on Living Cells

Oberbek, Przemyslaw, et al. Beilstein Journal of Nanotechnology 9.1 (2018): 3079-3094.

Nanomaterials, such as hydroxyapatite nanoparticles, show great promise in medical applications due to their unique properties at the nanoscale. However, there are concerns about the safety of using these materials in biological environments. Although a large number of studies have been published on nano-objects and their aggregates or agglomerates, the effects of their physicochemical properties (e.g., particle size, surface area, purity, structural details, and degree of agglomeration) on living cells are not fully understood. The correlation between the properties of nano-sized hydroxyapatites prepared by different synthetic methods and the biological activities represented by the viability of four cell lines (A549, CHO, BEAS2B, and J774.1) was investigated to evaluate the effects of the nanoparticles on the immune, reproductive, and respiratory systems.
Transmission electron microscopy was used to determine the average size (AS) and shape of the particles. Hydroxyapatite was observed using a LaB cathode at an accelerating voltage of 100 kV. The samples were prepared by suspending a small amount of nanopowder in ethanol followed by 5 min of ultrasonication. The samples were then left for about 10 min to evaporate the ethanol. Then, they were dropped onto the surface of a carbon-coated copper grid. Using a representative TEM image, the size of the crystallites was measured using software. The average value was calculated from no less than 200 particles. The pixel size was 1.8 nm × 1.8 nm.

Hydroxyapatite Nanopowder Effectively Removes Strontium Ions from Aqueous Solutions

Predoi, Silviu Adrian, et al. Materials 16.1 (2022): 229.

Drinking water contamination has become a worldwide problem due to the serious negative impacts of pollutants on the human body and the environment. Hydroxyapatite (HAp) has the right properties to fix various pollutants and is considered as one of the most cost-effective materials for water purification. The synthesized hydroxyapatite powder (HAp) was analyzed before and after the elimination of Srions from the contaminated solution. The efficiency of HAp nanoparticles in removing Srions from the contaminated solution was determined by batch adsorption experiments. HAp samples before and after the removal of Srions were studied by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). The ability of HAp nanoparticles to eliminate Strontium ions from the contaminated solution has been confirmed. In addition, ultrasonic measurements highlighted the removal of Srions from the contaminated aqueous solution. After the removal of Srions from the contaminated solution, the stability parameter values calculated by ultrasonic measurements were similar to those obtained using the stability of double distilled water as a reference. The results of the batch experiments highlighted that HAp nanoparticles could be excellent candidates for the development of new technologies for water remediation. More importantly, the results of the cytotoxicity assays proved that HAp nanoparticles did not cause any significant detrimental effects on HeLa cells and did not affect their proliferation after 1 and 7 days of incubation.
The crystal structure of HAp powder and its phases was studied by X-ray diffraction equipment using CuKα radiation (λ = 1.5418 Å) and an incident angle of 0.5. The XRD diffraction patterns were obtained within the 2 theta range of 15-65. The step size was 0.001 (2 theta). The microstructure of hydroxyapatite powder (before and after decontamination experiments) was studied using the equipment. For the chemical composition, the microscope was equipped with an X-ray Energy Dispersive Spectroscopy (EDX) unit. The FTIR studies were performed with the help of a spectrometer. During the studies, the spectrometer was operated in the ATR (attenuated total reflection) mode. The ATR-FTIR spectra were recorded in the spectral range of 450-4000 cm to study the samples without further preparation.

Hydroxyapatite Nanoparticles in Drug Delivery

Lara-Ochoa, Sofía, Wendy Ortega-Lara, and Carlos Enrique Guerrero-Beltrán. Pharmaceutics 13.10 (2021): 1642.

Hydroxyapatite (HAP) has become the gold standard in the biomedical field due to its composition and similarity to human bone. Properties such as shape, size, morphology, and ion substitution can be tailored by using different synthesis techniques and compounds. Whether its physicochemical properties can be determined, conclusions on their relevance to biological responses have not yet been found. Therefore, special attention needs to be paid to the most ideal properties for appropriate biological responses. Hydroxyapatite nanoparticles can be used as drug delivery systems. The analysis of chemical and physical interactions between nanoparticles and cargo has been emphasized by using spectroscopic and physical techniques such as FTIR, Raman, XRD, SEM, DLS, and BET.
Mesoporous HAP nanoparticles were used to deliver doxorubicin and vancomycin; the mesoporous nature of the nanoparticles can be determined by the type of isotherms from adsorption-desorption studies. Mesoporous materials usually exhibit type IV or type I isotherms, and the shape of the graph is associated with capillary condensation processes, which usually occur on pores with a size range of 2 to 50 nm. Although porosity has been shown to improve cell adhesion of osteoclasts, the major drawback of these platforms is that the extremely small pores do not have the capacity to adsorb large amounts of large molecular weight biomolecules. In this regard, mesoporous HAPs with larger pores of approximately 10-12 nm can be synthesized to design drug delivery systems.

Biomedical Applications of Hydroxyapatite Nanoparticles

Loo, S. C. J., et al. Current pharmaceutical biotechnology 11.4 (2010): 333-342.

Nanotechnology has the potential to improve current disease diagnostics due to their ability to circulate in the blood and distribute in the body to image tissues and cells or deliver payloads in therapeutic applications. Among nanoparticles composed of different materials, inorganic nanoparticles composed of calcium phosphate have many advantages, including ease of synthesis, controllable physicochemical properties, strong interactions with their payloads, and biocompatibility. Different synthetic routes, new systems, loading agent strategies, biostability and cytotoxicity, biodistribution and pharmacokinetics, bioimaging, and therapeutic applications of calcium phosphate nanoparticles are discussed.
Understanding the in vivo behavior of hydroxyapatite NPs (nHA) is essential to predict their imaging and therapeutic potential. In vivo evaluation of nHA includes the activity, biodistribution, and pharmacokinetic properties of the particles. Ultimately these properties are determined by the size, surface charge, morphology, and surface chemistry of the nHA. Small (<10 nm) particles are usually eliminated from the body by renal clearance, i.e., filtration by the kidneys and excretion through the urine. In contrast, larger nanoparticles are phagocytosed by tissue macrophages of the reticuloendothelial system (RES) in the liver and spleen. Radiolabeled rod-shaped nHA of varying sizes have been studied in vivo [98]. Intravenous injection of nHA (40 nm and 200 nm) showed clearance from the bloodstream within two hours, with 90% being cleared within the first 10 minutes after injection. These results suggest that bloodstream clearance is rapid for a variety of nHA sizes. Nanoparticles were primarily observed in the liver, with a few observed in the spleen.