Co-encapsulation of curcumin and boswellic acids in chitosan-coated niosome: an in-vitro digestion study.

In this study, chitosan-coated niosome (ChN) was utilised for bioavailability enhancement of curcumin (Cn) and boswellic acids (BAs). The bare niosome (BN) was prepared by the heating method and optimised by using the mixture design procedure. Physicochemical stability, as well as the in vitro release, and bioavailability of Cn and BAs in BN and ChN were studied. The optimised BN had a mean diameter of 70.00 ± 0.21 nm and surface charge of -31.00 ± 0.25 mv, which changed to 60.01 ± 0.20 nm and +40.00 ± 0, respectively, in ChN. In-vitro digestion study revealed chitosan layer augmented the bioavailability of Cn and BAs to 79.02 ± 0.13 and 81 ± 0.10, respectively. The chitosan layer obviously improved the physical stability of Cn and BA in the niosome vehicle, by means of vesicle size, zeta potential, and encapsulation efficiency. The ChN was considered to be promising delivery system for increasing the bioavailability of Cn and BAs.

Chitosan-coated niosome as an efficient curcumin carrier to cross the blood-brain barrier: an animal study.

This study aims to improve the curcumin bio-stability and brain permeability by loading in bare niosome (BN) and chitosan-coated niosome (ChN). Span 60, tween 60, and cholesterol were optimized as niosome shell components to attain the highest encapsulation efficiency (EE), besides the lowest particle size, using the mixture design method. The resulting optimized BN had a mean diameter of 80 ± 0.2 nm and surface charge of -31 ± 0.1 mv, which changed to 85 ± 0.15 nm and 35 ± 0.12 mv, respectively, after applying the chitosan layer. The EE% in bare niosome were about 80 ± 0.2, which changed to 82 ± 0.21 in ChN. The optimized formulation displayed sustained release, following the Hixson-Crowell model.Wistar rats were subjected to intraperitoneal injection (i.p.) of BN and ChN to evaluate the blood-brain barrier permeability of the curcumin. In this regard, ChN significantly increased curcumin concentration in different parts of the liver, plasma, and central nervous system (cerebral cortex, cerebellum, and stratum), compared with BN. Altogether, our results showed that ChN could be used as a promising delivery system for the treatment of some neurological diseases such as Alzheimer's.

Coinciding significance of the crystallographic orientation and nanostructuring on the biocompatibility of TZNT-Ag1.5 alloy deformed by the cold rolling process.

In this study, the simultaneous significance of the crystallographic texture and nanostructuring on the cytocompatibility of as-cast (Ti55 Zr25 Nb10 Ta10 )98.5 -Ag1.5 alloy (at. %, TZNT-Ag1.5 ), subjected to cold rolling up to 90% reduction, along with the changes of Young's modulus and hardness under cold rolling were investigated. For this purpose, the as-cast and cold-rolled TZNT-Ag1.5 alloy test specimens were analyzed by XRD, TEM, HRTEM, SEM, contact angle, nanoindentation, and OM techniques. Moreover, to evaluate the effect of severe cold deformation on the biocompatibility, MG-63 osteoblastic cell was cultured on the surface of 90% cold-rolled and as-cast test specimens of TZNT-Ag1.5 alloy. The results showed that severe cold deformation was led to fast grain refinement of ß grains of the as-cast TZNT-Ag1.5 alloy in the range of 50-100 nm. In addition to the nanostructuring, upon severe cold deformation, the -fiber (<111>// normal direction) texture was formed and after 90% reduction, the (111)<1 1¯0 > γ-fiber component was strengthened. The micro-hardness and reduced Young's modulus are 235 ± 5.29, 246 ± 1.73, 271 ± 4.0, and 283 ± 6.25 (HV); and 73.725 ± 1.70, 83.98 ± 5.10, 81.26 ± 6.55, and 88.66 ± 7.16 (GPa) for TZNT-Ag1.5 (as-cast), TZNT-Ag1.5 (20%CR), TZNT-Ag1.5 (50%CR), and TZNT-Ag1.5 (90%CR) test specimens, respectively. Further, with increasing the cold deformation degree, the dislocation density of TZNT-Ag1.5 alloy increased as this parameter is 2.79 × 1015 (m-2 ) for the 90%CR test specimen. On the other hand, the values of the contact angle for the 90%CR test specimen (46.2 ± 3.5°) exhibit a higher hydrophilic and wettable surface as compared to the other studied test specimens. After 5 days of incubation, osteoblastic cells on the surface of the 90% cold-rolled TZNT-Ag1.5 test specimens revealed significant differences in cell proliferation and differentiation as compared to the as-cast alloy test specimens and/or CP-Ti. Finally, because the maximum orientation intensities were generally <3, it was deduced that grain refinement rather than the crystallographic texture plays a significant role in improving the surface biocompatibility of the new TZNT-Ag1.5 alloy.

A study on the mechanical properties and corrosion behavior of the new as-cast TZNT alloys for biomedical applications.

In this study, four different TZNT based alloys, (Ti55Zr25Nb10Ta10, (Ti55Zr25Nb10Ta10)99.5Fe0.5, (Ti55Zr25Nb10Ta10)98Sn2, and (Ti55Zr25Nb10Ta10)98.5Ag1.5, (at. %), designated TZNT, TZNT-Fe, TZNT-Sn, TZNT-Ag, respectively) are produced by non-consumable vacuum arc melting and suction casting. These alloys using the d-electron alloy design method and considering the criteria of [Mo]eq and (e/a) ratio for ß-phase Ti alloys are designed. The microstructure, mechanical properties, and corrosion behavior of the alloys are investigated via optical microscopy, scanning electron microscopy, X-ray diffraction, nanoindentation, and electrochemical tests. The designed alloys exhibit dendritic morphology, however, the TZNT-Ag alloy indicates a more homogenous microstructure after suction casting. X-ray diffraction analyses reveal not only the beta phase in the TZNT, TZNT-Fe, and TZNT-Ag alloys, but also beta lean/beta rich separation in the TZNT-Sn alloy. In addition to the microstructural features, the new TZNT alloys show very high ductility upon cold compressive deformation, as well as the lowest Young's modulus (65.54±1.7 GPa, P<0.05) is achieved in TZNT-Ag alloy. Furthermore, the compressive yield stress to Young's modulus (Ycys/E) ratio of the designed alloys is in the range of 0.92-1.08%. In terms of corrosion behavior, Ag increases the corrosion resistance of the TZNT alloy in Ringer's solution. As a result, owing to the effect of Ag on the optimization of the mechanical properties and corrosion resistance of the TZNT alloy, the as-cast Ag-containing TZNT alloy can be developed to be a promising candidate for biomedical applications.

Electrochemical and biological characterization HA/Al2 O3 -YSZ nano-composite coatings using electrophoretic process.

In this research work, hydroxyapatite/alumina/YSZ bio nanocomposite coatings on titanium substrate were created by electrophoretic deposition (EPD) and reaction bonding process. By using the EPD process, uniform green form coatings containing HA, yttria-stabilized zirconia (YSZ), and aluminum particles were produced on titanium. After oxidation of aluminum at 660°C and sintering at 850°C, a dense and adherent HA/Al2 O3 /YSZ coating was produced. Scanning electron microscopy, X-ray diffractometric and mechanical tests were employed to investigate the morphologies, compositions, hardness, toughness and bonding strength of the coatings. The corrosion studies and cell culturing experiment were carried out and the results show that the HA/YSZ/Al2 O3 coatings are more bioactive and more resistance to corrosion than HA coatings. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 1916-1922, 2018.

The removal of mercury (II) from water by Ag supported on nanomesoporous silica.

In this study, the synthesis of SBA-15/Ag nanocomposite materials with different amounts of silver (2.5, 5, and 10 %) has been investigated under acidic conditions by using P123 as a template via the direct method. The nanocomposites of SBA-15 were synthesized by the same method and by the addition of silver salt. Finally, the nanocomposite materials were examined for the removal of mercury ions from wastewater as an adsorbent by the reverse titration method. Characterization was carried out through x-ray diffraction analysis (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and N2 adsorption-desorption (Brunauer-Emmett-Teller). XRD spectra confirmed the presence of silver nanoparticles within the amorphous silica matrix of SBA-15. The Barrett-Joyner-Halenda analysis showed that SBA-15 and SBA-15/Ag have a narrow pore size distribution. SEM images demonstrated that the morphology of the matrix of SBA-15 is in spherical state. Furthermore, wavelength dispersive x-ray spectroscopy identified the presence and distribution of silver nanoparticles inside the pore channels and outside of them. Typical TEM images of SBA-15 and SBA-15/Ag (5 wt.%) indicated a regular hexagonal pore structure with long-range order and long channels. In SBA-15/Ag (5 wt.%) sample, the nanoparticles of silver was found into the pores and outside of them. The removal of mercury ions from wastewater using mesoporous silica nanocomposite containing silver nanoparticles was studied by the reverse titration analysis. The best capacity of adsorption of mercury ions from wastewater was obtained for SBA-15/Ag (5 wt.%) sample, which was equal to 42.26 mg/g in 20 min at pH of 7. The Freundlich model was used to explain the adsorption characteristics for the heterogeneous surface, and [Formula: see text] (adsorption capacity) and n (adsorption intensity) were determined for Hg (II) ion adsorption on SBA-15/Ag nanocomposite materials with different amounts of silver (2.5, 5, and 10 %). The value of R2 was about 0.99, 0.99, 0.98, and 0.98 and Kf was about 42, 48, 58, and 58 mg/g for SBA-15/Ag, SBA-15/Ag (2.5 %), SBA-15/Ag (5 %), and SBA-15/Ag (10 %), respectively. Furthermore, the values of n >1 show a favorable adsorption process for Hg (II) ion adsorption on SBA-15/Ag nanocomposite materials. Moreover, the Langmuir isotherm model evaluation showed that the correlation coefficients for all concentrations were R2 >0.99, indicating that Hg (II) ions were adsorbed on the surface of SBA-15/Ag via chemical and physical interaction. Additionally, the analytic hierarchy process (AHP) and Technique of Order Preference Similarity to the Ideal Solution (TOPSIS) methods that depend on the criteria of the surface area, amount of adsorbent, pore volume, and cost of synthesis were used. The evaluation of results showed that the best sample was SBA-15/Ag (5 wt.%). Furthermore, the research work highlighted the antibacterial nanocomposite with suitable adsorption of Hg (II) ions from water solutions and supported its potential for environmental applications. This nanocomposite can be used in the absorption domain of Hg (II) ions from water solutions.

The relationship of surface roughness and cell response of chemical surface modification of titanium.

Implant surface topography influences osteoblastic proliferation, differentiation and extracellular matrix protein expressions. Previous researches proved that chemical surface modification of titanium implants could be used to improve Bone-to-implant contact. In this study, the surface topography, chemistry and biocompatibility of polished titanium surfaces treated with mixed solution of three acids containing HCl, HF and H(3)PO(4) with different etched conditions for example concentration, time and addition of calcium chloride were studied. Osteoblast cells (MG-63) were cultured on different groups of titanium surfaces. In order to investigate titanium surfaces, SEM, AFM and EDS analyses were carried out. The results showed that surfaces treated with HCl-HF-H(3)PO(4) had higher roughness, lower cytotoxicity level and better biocompatibility than controls. Moreover, addition of calcium chloride into mixed solution of three acids containing HCl, HF and H(3)PO(4) is an important, predominant and new technique for obtaining biofunction in metals for biomedical use including dentistry.

Electrodeposition of TiO2-RuO2-IrO2 coating on titanium substrate.

TiO2, RuO2, and IrO2 transition metal oxides have many applications in the field of applied electrochemistry. In this work, the mixed solid solutions of TiO2-RuO2-IrO2 coatings have been electrodeposited from aqueous-unaqueous baths. Moreover, the obtained coatings have been heated in the electric furnace at 450 °C. The microstructure of coating was characterized using scanning electron microscopy (SEM) and Atomic force microscopy (AFM). In order to investigate, the chemical composition and crystalline phases of coating, X-ray analysis, energy dispersive spectroscopy (EDS) were carried out. Furthermore, anodic polarization behavior of coating was investigated. Results show that heat treated coating at 450 °C with the chemical composition of TiO2/RuO2/IrO2 with molar ratio of 70/5/25 with six layer on substrate has the highest quality, stability, adhesion strength and minimum chlorine overvoltage. However, increasing the iridium content in electrolyte enhances the coating thickness and the quality of morphology.