Effect of L-Glutamic Acid on the Composition and Morphology of Nanostructured Calcium Phosphate as Biomaterial

• Published in: Materials Vol. 16; no. 3; p. 1262
• Main Authors: Takabait, Fatah, Martínez-Martínez, Sergio, Mahtout, Laila, Graba, Zahra, Sánchez-Soto, Pedro J, Pérez-Villarejo, Luis
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 01.02.2023; MDPI
• Subjects: Amino acids; Apatite; Aqueous solutions; Biocompatibility; Biological activity; Biological products; Biomedical materials; brushite; Calcium carbonate; Calcium phosphate; Calcium phosphates; chelate complexes; Chemical composition; Chemical precipitation; Glutamate; Glutamic acid; Hydroxyapatite; L-glutamic acid; Mathematical analysis; Morphology; Nanostructured materials; Phosphoric acid; Polymorphism; Scanning electron microscopy; Slaked lime; Spectrum analysis; X-rays; California; apatite; L-glutamic acid; brushite; calcium phosphate; phosphoric acid; chelate complexes; biomaterials
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma16031262

Calcium phosphate (CaP) with several chemical compositions and morphologies was prepared by precipitation using aqueous solutions of L-Glutamic acid (H G) and calcium hydroxide, both mixed together with an aqueous solution (0.15 M) of phosphoric acid. Plate-shaped dicalcium phosphate dihydrate (brushite) particles were obtained and identified at a lower concentration of the solution of the reactants. The Ca/P ratio deduced by EDS was ~1, as expected. The nanoscale dimension of carbonate apatite and amorphous calcium phosphate, with variable Ca/P ratios, were revealed by X-ray diffraction (XRD) and scanning electron microscopy and energy dispersive X-ray spectroscopy analysis (SEM-EDS). They were characterized in medium and high concentrations of calcium hydroxide (0.15 M and 0.20 M). The equilibria involved in all the reactions in aqueous solution were determined. The thermodynamic calculations showed a decrease in the amount of chelate complexes with an increase in pH, being the opposite of [CaPO ] and [CaHG ]. This fluctuation showed an evident influence on the morphology and polymorphism of CaP particles obtained under the present experimental conditions, with potential use as a biomaterial.