MORPHOLOGICAL AND CHEMICAL PROPERTIES OF SPHERICAL AND NEEDLE CALCIUM PHOSPHATE BIONS

Abstract

Aim To compare morphological properties, mineral, and organic profile of spherical calcium phosphate bions (SCPB) and needle calcium phosphate bions (NCPB) for the assessment of the CPB-specific endothelial toxicity in models of mild or severe hypercalcemia/hyperphosphatemia in the further studies. Methods Both SCPB and NCPB were artificially synthesized employing blood-mimetic medium either moderately or significantly supersaturated of calcium and phosphorus salts. Size and shape of SCPB and NCPB were investigated by scanning and transmission electron microscopy and atomic force microscopy. Elemental analysis was performed utilizing energy-dispersive X-ray spectroscopy, atomic emission spectroscopy, and CHNSO analysis, functional groups were examined using Fourier-transform infrared spectroscopy and Raman spectroscopy while chemical formula was identified by X-ray powder diffraction analysis. Protein profile of SCPB and NCPB was screened employing sodium dodecyl sulfate polyacrylamide gel electrophoresis following silver staining. Results SCPB were visualized as crystalline spherical spongeous particles of 80-200 nm diameter and mean diameter of around 120 nm while NCPB represented needle crystals of a similar diameter. Both SCPB and NCPB had similar crystallinity, surface charge and tended to form clusters of several particles. Furthermore, both SCPB and NCPB were composed of carbon, oxygen, hydrogen, nitrogen, calcium, and phosphorus, contained phosphate (PO43-), carbonate (CO32-), and hydroxyl (OH-) functional groups, and consisted of hydroxyapatite (Ca10(PO4)6(OH)2) and carbonate-hydroxyapatite (Ca10(PO4)3(CO3)3(OH)2). In addition, protein profile of SCPB and NCPB was similar and notable for the abundant albumin and fetuin A levels. Conclusion Having similar size, surface charge, extent of crystallinity, and chemical composition, SCPB and NCPB possess a different shape.