Improving the Durability of Chitosan Films through Incorporation of Magnesium, Tungsten, and Graphene Oxides for Biomedical Applications.

Bacterial infections that cause chronic wounds provide a challenge to healthcare worldwide because they frequently impede healing and cause a variety of problems. In this study, loaded with tungsten oxide (WO3 ), Magnesium oxide (MgO), and graphene oxide (GO) on chitosan (CS) membrane, an inexpensive polymer casting method was successfully prepared for wound healing applications. All fabricated composites were characterized by X-ray powder diffraction (XRD), Fourier transforms infrared spectroscopy (FT-IR), and thermogravimetric analysis (TGA). A scanning electron microscope (SEM) was used to study the synthesized film samples' morphology as well as their microstructure. The formed WO3/MgO@CS shows a great enhancement in the UV/VIS analysis with a highly intense peak at 401 nm and a narrow band gap (3.69 eV) compared to pure CS. The enhanced electron-hole pair separation rate is responsible for the WO3/MgO/GO@CS scaffold's antibacterial activity. Additionally, human lung cells were used to determine the average cell viability of nanocomposite scaffolds and reached 121 % of WO3 /MgO/GO@CS nanocomposite, and the IC50 value was found to be 1654 µg/mL. The ability of the scaffold to inhibit the bacteria has been tested against both E. coli and S. aureus. The 4th sample showed an inhibition zone of 11.5±0.5 mm and 13.5±0.5 mm, respectively. These findings demonstrate the enormous potential for WO3 /MgO/GO@CS membrane as wound dressings in the clinical management of bacterially infected wounds.

Corrosion mitigation characteristics of some novel organoselenium thiourea derivatives for acid pickling of C1018 steel via experimental and theoretical study.

Two organoselenium thiourea derivatives, 1-(4-(methylselanyl)phenyl)-3-phenylthiourea (DS036) and 1-(4-(benzylselanyl)phenyl)-3-phenylthiourea (DS038) were produced and categorized using FTIR and NMR (1H and 13C). The effectiveness of the above two compounds as C-steel corrosion inhibitors in molar HCl was evaluated using the potentiodynamic polarization (PD) and electrochemical impedance spectroscopy (EIS) techniques. PD findings indicate that DS036 and DS038 have mixed-type features. EIS results show that growing their dose not only changes the polarization resistance of C-steel from 18.53 to 363.64 and 463.15 Ω cm2 but also alters the double layer capacitance from 710.9 to 49.7 and 20.5 µF cm-2 in the occurrence of 1.0 mM of DS036 and DS038, respectively. At a 1.0 mM dose, the organoselenium thiourea derivatives displayed the highest inhibition efficiency of 96.65% and 98.54%. The inhibitory molecule adsorption proceeded along the Langmuir isotherm on the steel substrate. The adsorption-free energy of the adsorption process was also intended and indicated a combined chemical and physical adsorption on the C-steel interface. FE-SEM studies support the adsorption and protective abilities of the OSe-based molecule inhibitor systems. In Silico calculations (DFT and MC simulations) explored the attraction between the studied organoselenium thiourea derivatives and corrosive solution anions on a Fe (110) surface. The obtained results show that these compounds can make a suitable preventing surface and control the corrosion rate.

A Novel Electrochemical Sensor Based on an Environmentally Friendly Synthesis of Magnetic Chitosan Nanocomposite Carbon Paste Electrode for the Determination of Diclofenac to Control Inflammation.

A simple and eco-friendly electrochemical sensor for the anti-inflammatory diclofenac (DIC) was developed in a chitosan nanocomposite carbon paste electrode (M-Chs NC/CPE). The M-Chs NC/CPE was characterized with FTIR, XRD, SEM, and TEM for the size, surface area, and morphology. The produced electrode showed a high electrocatalytic activity to use the DIC in 0.1 M of the BR buffer (pH 3.0). The effect of scanning speed and pH on the DIC oxidation peak suggests that the DIC electrode process has a typical diffusion characteristic with two electrons and two protons. Furthermore, the peak current linearly proportional to the DIC concentration ranged from 0.025 M to 4.0 M with the correlation coefficient (r2). The sensitivity, limit of detection (LOD; 3σ), and the limit of quantification (LOQ; 10σ) were 0.993, 9.6 µA/µM cm2, 0.007 µM, and 0.024 µM, respectively. In the end, the proposed sensor enables the reliable and sensitive detection of DIC in biological and pharmaceutical samples.

Cd(II) and Pd(II) Mixed Ligand Complexes of Dithiocarbamate and Tertiary Phosphine Ligands-Spectroscopic, Anti-Microbial, and Computational Studies.

Mixed ligand complexes of Pd(II) and Cd(II) with N-picolyl-amine dithiocarbamate (PAC-dtc) as primary ligand and tertiary phosphine ligand as secondary ligands have been synthesized and characterized via elemental analysis, molar conductance, NMR (1H and 31P), and IR techniques. The PAC-dtc ligand displayed in a monodentate fashion via sulfur atom whereas diphosphine ligands coordinated as a bidentate mode to afford a square planner around the Pd(II) ion or tetrahedral around the Cd(II) ion. Except for complexes [Cd(PAC-dtc)2(dppe)] and [Cd(PAC-dtc)2(PPh3)2], the prepared complexes showed significant antimicrobial activity when evaluated against Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans and Aspergillus niger. Moreover, DFT calculations were performed to investigate three complexes {[Pd(PAC-dtc)2(dppe)](1), [Cd(PAC-dtc)2(dppe)](2), [Cd(PAC-dtc)2(PPh3)2](7)}, and their quantum parameters were evaluated using the Gaussian 09 program at the B3LYP/Lanl2dz theoretical level. The optimized structures of the three complexes were square planar and tetrahedral geometry. The calculated bond lengths and bond angles showed a slightly distorted tetrahedral geometry for [Cd(PAC-dtc)2(dppe)](2) compared to [Cd(PAC-dtc)2(PPh3)2](7) due to the ring constrain in the dppe ligand. Moreover, the [Pd(PAC-dtc)2(dppe)](1) complex showed higher stability compared to Cd(2) and Cd(7) complexes which can be attributed to the higher back-donation of Pd(1) complex.

Zinc oxide calcium silicate composite attenuates acute tramadol toxicity in mice.

BACKGROUND: Seizures are considered to be the most common symptom encountered in emergency- rushed tramadol-poisoned patients; accounting for 8% of the drug-induced seizure cases. Although, diazepam clears these seizures, the risk of central respiratory depression cannot be overlooked. Henceforth, three adsorbing composites were examined in a tramadol acute intoxication mouse model. METHODS: Calcium Silicate (Wollastonite) either non-doped or wet doped with iron oxide (3%Fe2O3) or zinc oxide (30% ZnO) were prepared. The composites' adsorption capacity for tramadol was determined in vitro. Tramadol intoxication was induced in Swiss albino mice by a parenteral dose of 120 mg/kg. Proposed treatments were administered within 1 min at 5 increasing doses, i.p. The next 30 min, seizures were monitored as an intoxication symptom. Plasma tramadol concentration was recorded after two hours of administration. RESULTS: The 3% Fe2O3-containing composite (CSFe3), was found to be composed of mainly wollastonite with very little alpha-hematite. On the other hand, hardystonite and wellimite were developed in the 30%ZnO-containing composite (CSZn3). Micro-round and irregular nano-sized microstructures were established (The particle size of CS was 56 nm, CSFe3 was 49 nm, and CSZn3 was 42 nm). The CSZn3 adsorption capacity reached 1497 mg of tramadol for each gram. Tramadol concentration was reduced in plasma and seizures were inhibited after its administration to mice at three doses. CONCLUSION: The calcium silicate composite doped with ZnO presented a good resolution of tramadol-induced seizures accompanied by detoxification of blood, indicating its potential for application in such cases. Further studies are required.

Osteogenic potential of calcium silicate-doped iron oxide nanoparticles versus calcium silicate for reconstruction of critical-sized mandibular defects: An experimental study in dog model.

Objective: To evaluate bioactivity and osteogenic potential of calcium silicate (CS)-doped iron oxide (Fe2O3) nanoparticles versus pure CS in the reconstruction of induced critical-sized mandibular defects. Design: CS-doped Fe2O3 was prepared; morphological and microstructure identification of nanoparticles were made. An in vivo randomised design was developed on 24 adult male dogs where four critical-sized mandibular defects were created in each dog. Bone defects were allocated into control, CS, CS-3% Fe2O3 and CS-10% Fe2O3 group. Dogs were euthanized at 1 and 3 months (12 dog/time) for histopathologic and histomorphometric evaluation. Results: At three months, bone formation and maturation were evident where mean ± SD percent of mature bone was 2.66 ± 1.8, 9.9 ± 2.5, 22.9 ± 4.9, and 38.6 ± 8.1 in control, CS, CS-3% Fe2O3, and CS-10% Fe2O3 groups respectively. A high significant (P < 0.001) increase in area percent of mature bone was recorded in CS, CS-3% Fe2O3, and CS- 10% Fe2O3 groups compared to control group (73%, 88% and 93.3% respectively). Significant increase (P < 0.001) in area of mature bone was recorded in CS-3% Fe2O3 and CS-10% Fe2O3 groups compared to CS group. A significant increase (P < 0.001) in area of mature bone formation was detected in CS-10% Fe2O3 group compared to other groups. Conclusion: CS-doped Fe2O3 has good osteoconductive, biocompatible properties with promoted bone regeneration. Fe2O3 has synergistic effect in combination with CS to promote bone formation. Increasing concentration of Fe2O3 nanoparticles resulted in improved osteogenesis and maturation. Results suggests that the novel CS-Fe2O3 alloplasts could be used for reconstruction of critical-sized bone defects.

Radiological evaluations of low cost wollastonite nano-ceramics graft doped with iron oxide in the treatment of induced defects in canine mandible.

Wollastonite with/without maghemite [(Fe2O3), 0, 3 and 10 wt%] was prepared by facile wet precipitation method. Effect of Fe2O3 presence in the obtained nano-ceramics on physical structure, morphology, size and the mechanical features was evaluated using X-ray diffraction, transmission electron microscope, and universal testing machine. Moreover, the in vitro biomineralization was examined using simulated body fluid (SBF) by means of scanning electron microscope/energy dispersive X-ray, Fourier transform infrared, and inductively coupled plasma. An in vivo study was conducted on 24 adult male mongrel dogs to test the biosafety of fabricated samples in the reconstruction of experimentally induced mandibular bone defects. Bone density was measured through cone beam computed tomography analysis conducted at 1 and 3 months following surgery. Wollastonite was the main phase in all the prepared samples however little maghemite was developed in Fe-containing samples. No remarkable changes were recognized for physical structure of obtained microcrystalline structures, however, a decrease in particle size was noted in the existence of Fe2O3 (10-15 nm) when compared to the pure wollastonite (30-50 nm). Mechanical features were dependent on the included Fe2O3 concentration within the wollastonite ceramic matrix. The degree of biomineralization of the samples immersed in SBF was elevated with the increase in Fe2O3 percentage. Clinically, the reconstruction of bone defects was uneventful without any adverse toxic effect. Bone density was significantly increased at 1 and 3 months (p < .001) in grafted defects compared to control ones. Increasing the doping concentrations of iron oxide was associated with significant increase (p < .001) of bone density in all induced defects. Due to the impressive healing effect of current fabricated nano-ceramics, they are recommended to be utilized as low cost bone graft alternatives.

Hydroxyapatite nanoparticles derived from mussel shells for in vitro cytotoxicity test and cell viability.

Hydroxyapatite (HA) nanoparticles derived from mussel shells were prepared using the wet precipitation method and were tested on human mesenchymal and epithelial cells. Shells and HA powder were characterized via X-ray diffraction analysis (XRD) and scanning electron microscopy along with energy dispersive X-ray spectroscopy (SEM/EDX), high resolution transmission electron microscopy (HR-TEM) and Fourier transform infrared spectroscopy (FTIR). The in vitro cytotoxic properties of HA and mussel shells were determined using sulphorhodamine B (SRB) assays for MCF-7 cells (HepG2) and colon (Caco-2) cells. Cell viability tests confirmed the nontoxic effects of synthesized HA and mussel shells on human mesenchymal stem cells (h-MSCs) and epithelial cells. Toxicity values were less than 50% of the cell's validity ratio based on analyses using different concentrations (from 0.01 to 1,000 µg). The results indicate that MSC and epithelial cell attachment and proliferation in the presence of both HA and shell occurred. The proliferation capability was established after 3 and 7 days. SEM images revealed that stem cells and epithelial cells attached to the scaffold indicated full and complete integration between the cells and the material. It seems that due to the ion exchange between bovine serum albumin solutions (BSA) and HA, the FTIR data confirmed an increase in the amide I and amide II bands, which indicates the compatibility of the BSA helix structure. This study sheds light on the importance of merging stem cells and nanomaterials that may lead to improvements in tissue engineering to develop novel treatments for various diseases.

Hybrid Membranes Based on Clay-Polymer for Removing Methylene Blue from Water.

Water pollution is a serious environmental problem. Methylene blue is among the dyes that may exist in waste water. Adsorption is an effective process to remove dyes from contaminated water. Hybrid membranes based on clay-polymer; namely kaolin and polystyrene were prepared to absorb the present methylene blue in aqueous solution. These membranes were fired at 1000 °C to degrade polystyrene leaving cavities in the clay matrix with an expanded surface area and porous structure. The membranes were characterized via X-ray diffraction and Infrared spectroscopy. The morphological structure was investigated by using scanning electron microscopy. In this work, we are focusing on facile means represented in UV-Vis spectroscopy, to monitor the adsorption efficiency of the prepared membranes. From the results, the membrane loaded with 20 % polystyrene by weight showed the optimum performance in adsorbing methylene blue from water.

Synthesis and characterization high purity alumina nanorods by a novel and simple method using nanocellulose aerogel template.

Highly porous nanofibrillated cellulose aerogel fibers (NFCA) prepared from bagasse pulp was used as a template for in situ preparation of alumina nanorods. NFCA was soaked in aluminum nitrate aqueous solution followed by soaking in ammonium hydroxide solution to generate aluminum hydroxide within the porous structure and at surface of NFCA. Sintering of NFCA/Al (OH)3 was carried out at 1100 °C to produce nano-sized alumina with rod-like structure. The synthesized Al2O3 nanorods were investigated using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), and high resolution transmitted electron microscope (HR-TEM). The Al2O3 rods had width from 123 to 86 nm while their length was in the micrometer range, as shown from SEM and HR-TEM images. The selected area X-ray diffraction (SEAD) showed rhombohedral crystal structure. XRD pattern confirmed formation of α-alumina. Energy dispersive X-ray spectroscopy (EDX) showed purity of the prepared Al2O3.

Novel, cost-effective, Cu-doped calcium silicate nanoparticles for bone fracture intervention: Inherent bioactivity and in vivo performance.

Copper (Cu)-doped calcium silicate nanoparticles were synthesized by a wet precipitation method as economical bone fracture filler. The aim was to improve the overall physicochemical properties, bioactivity, and biological performance of the bone fracture filler prepared herein. The synthesized nanoparticles were evaluated using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and transmission electron microscopy (TEM). The bioactivity of the prepared nanoparticles was investigated after immersion in simulated body fluid (SBF) by means of inductively coupled plasma (ICP), SEM coupled with energy dispersive X-rays (EDX), and FTIR. The size and bioactivity of the prepared nanoparticles after 15 days of immersion in SBF was dependent on the Cu concentrations. The fracture healing ability of the fabricated nanoparticles on adult aged male Wistar rats was enhanced by the presence of copper. All the obtained results are of high relevance for fabricating improved Cu-doped calcium silicate nanoparticles (∼50 nm) as low cost bone fracture filler. In addition, the in vivo study presented complete healing of the tibiae bone with normal architecture of bone tissue specifically calcium silicate nanoparticles doped with 3% and 5% Cu. Hence, the presence of copper is a promising tactic for improving the biological properties of calcium silicate. Therefore, the designed nanoparticles have huge potential for the treatment of bone fractures. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 107B: 388-399, 2019.

Synthesis and characterization of laminated Si/SiC composites.

Laminated Si/SiC ceramics were synthesized from porous preforms of biogenous carbon impregnated with Si slurry at a temperature of 1500 °C for 2 h. Due to the capillarity infiltration with Si, both intrinsic micro- and macrostructure in the carbon preform were retained within the final ceramics. The SEM micrographs indicate that the final material exhibits a distinguished laminar structure with successive Si/SiC layers. The produced composites show weight gain of ≈5% after heat treatment in air at 1300 °C for 50 h. The produced bodies could be used as high temperature gas filters as indicated from the permeability results.