Crystallization behavior of tantalum and chlorine co-substituted hydroxyapatite nanopowders

Antimicrobial activity of Hydroxyapatite nanoparticles prepared from marble wastes

This work aims to prepare and characterize the hydroxyapatite (HAP) nanomaterials from marble wastes (the utilization of the building marble waste for reducing the environmental pollution hazards) and to study its capabilities as antimicrobial and antifungal agents of the prepared nanoparticle. The utilization of the marble waste as a source for calcium chloride and to be reacted with sodium hydrogen phosphate, for synthetization of hydroxyapatite nanoparticles, the prepared material is characterized, tested, and analyzed using X-ray diffraction (XRD), Scan Electron Microscope (SEM) with Energy Dispersive X-Ray analysis (EDAX) techniques. The antimicrobial activity of prepared hydroxyapatite nanomaterial is tested using a well diffusion method with different types of bacteria (Gram-negative): Escherichia. Coli, Salmonella paratyphi, Pseudomonas earuginosa, and Alcaligenes aquatilis and bacteria (Gram- positive): Staphylococcus aureus, and Streptococcacea pneumonia. The antifungal efficacy of HAP nanoparticles is tested for different species of Aspergillus niger, Aspergillus flavus, and Penicillium SP. The diameter of the inhibitory zone shows the sensitivity of the microorganism to HAP nanoparticles in a greater inhibition against Gram- positive Staphylococcus aureus and Streptococcacea pneumonia, at 100% DMSO concentration. The diameter of the inhibition zone was 03.70 mm, when compared with other types of bacteria. The diameter of the inhibitory zone showed the sensitivity of the microorganism to HAP nanoparticles in a greater inhibition against Penicillium SP at 100% DMSO concentration, the inhibition zone diameter was 2.20 mm, when compared with other Aspergillus niger and Aspergillus flavus fungal species. Based on obtained results for the HAP nanoparticles prepared from the marble wastes have antibacterial effects on both Gram-negative (E. coli) and Gram-positive (S. aureus) strains.

The deposition of strontium and zinc Co-substituted hydroxyapatite coatings

The in vitro and in vivo performance of hydroxyapatite (HAp) coatings can be modified by the addition of different trace ions, such as silicon (Si), lithium (Li), magnesium (Mg), zinc (Zn) or strontium (Sr) into the HAp lattice, to more closely mirror the complex chemistry of human bone. To date, most of the work in the literature has considered single ion-substituted materials and coatings, with limited reports on co-substituted calcium phosphate systems. The aim of this study was to investigate the potential of radio frequency magnetron sputtering to deposit Sr and Zn co-substituted HAp coatings using Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The FTIR and XPS results highlight that all of the Sr, Zn and Sr-Zn co-substituted surfaces produced are all dehydroxylated and are calcium deficient. All of the coatings contained HPO₄^2- groups, however; only the pure HAp coating and the Sr substituted HAp coating contained additional CO₃^2- groups. The XRD results highlight that none of the coatings produced in this study contain any other impurity CaP phases, showing peaks corresponding to that of ICDD file #01-072-1243 for HAp, albeit shifted to lower 2θ values due to the incorporation of Sr into the HAp lattice for Ca (in the Sr and Sr-Zn co-substituted surfaces only). Therefore, the results here clearly show that RF magnetron sputtering offers a simple means to deliver Sr and Zn co-substituted HAp coatings with enhanced surface properties. (a) XRD patterns for RF magnetron sputter deposited hydroxyapatite coatings and (b)-(d) for Sr, Zn and Sr-Zn co-substituted coatings, respectively. The XPS spectra in (b) confirms the presence of a HA sputter deposited coating as opposed to

Ion size, loading, and charge determine the mechanical properties, surface apatite, and cell growth of silver and tantalum doped calcium silicate

This study describes how various loadings of two ions with different size and charge, such as silver and tantalum, can affect the mechanical and biological properties of calcium silicate (CS).

Development of biocompatible hydroxyapatite–poly(ethylene glycol) core–shell nanoparticles as an improved drug carrier: structural and electrical characterizations

A model of a controlled drug release mechanism of a dielectric core–shell composite carrier.