Apatite matrix substituted with biologically essential rare earth elements as an artificial hard tissue substitute: Systematic physicochemical and biological evaluation

Abstract

Hydroxyapatite (HAP) forms the main inorganic component of natural bone and hence has been widely use in implant applications. Ionic substitutions in apatite also gains enormous interest during the recent years due to the crucial role played by these elements in the biological process. In this context, the least investigated elements namely lanthanum (La3+) and praseodymium (Pr3+) have been selected as a potential substitutions in apatite. The results from the analytical techniques confirm the phase purity of the HAP and its ability holds the substitutions at its lattice. Morphological analysis unveils the presence of agglomerated spheroids notwithstanding the ion concentration of substituents. EDX spectra affirm the presence of La and Pr alongside the determined Ca/P atomic ratio of 1.67. La3+ and Pr3+ presence envisaged the good antibacterial efficiency against the tested microbes and further demonstrated the biocompatibility nature from the cytotoxicity analysis.

Systematic review of the osteogenic effect of rare earth nanomaterials and the underlying mechanisms

“…The ionic radii of RE ions range from 0.0848 nm (Lu) to 0.1034 nm (Ce), which is similar to the Ca radius of 0.104 nm [ 31 ]. This implies that RE ions can substitute for Ca 2+ in HA, thereby increasing its physical and chemical stability in bones [ 32 ]. When RE ions interact with cells, they can activate Ca 2+ receptors such as calcium-sensitive receptors (CaRs), increasing intracellular Ca 2+ levels and promoting osteogenic differentiation [ 33 ].…”