Structural and biophysical peculiarities of Nd2O3 doped borate bioglass

Abstract

Different glasses with a variable composition of x Nd2O3.(46-x) B2O3.24.5 Na2O.26.5 CaO.2.6 P 2O5 (where X = 0–2.0 mol% of Nd2O3) were prepared and studied from the viewpoint of enhancing their bioactivities. All of the as-prepared glasses showed amorphous structures evidenced by the X-ray diffraction (XRD) patterns. On the other hand, XRD patterns of glasses soaked in sodium phosphate buffer solution revealed the formation of a variety of crystalline structures relevant to the formation of carbonated hydroxyapatite derivatives. According to the NMR data, the concentration of BO3 units increases at the expense of BO4 with increasing Nd2O3 content. Increasing of (BO3/BO4) molar ratio with increasing Nd2O3 plays the main role of enhancing the bioactivity of borate glasses. The percentage of BO3, BO4, and consequently N4 fraction (N4 =BO4/BO3+BO4) can simply be determined from the deconvolution process of FTIR and NMR spectra. A scanning electron microscope (SEM) and energy-dispersive x-ray (EDX) evaluation of the microstructures support the existence of crystalline HA after immersion. Both EDX and mapping of the sample after prolonged time intervals point to the homogeneity in the HA distribution of the studied sample.