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1.
Eur Rev Med Pharmacol Sci ; 27(9): 4202-4210, 2023 05.
Article in English | MEDLINE | ID: mdl-37203846

ABSTRACT

OBJECTIVE: Natural wound dressings composed of gelatin (GEL) and chitosan (CH) impregnated with bioactive compounds (Nigella sativa oil) were prepared and characterized to evaluate their potential application. MATERIALS AND METHODS: The formulated composite was subjected to γ-irradiation. In vitro, the ferric-reducing antioxidant power (FRAP) assay and antibiofilm activities were evaluated. In vivo, the tissue wound-healing process was studied by applying GEL-CH-Nigella in dorsal skin rabbit tissue. On days 7 and 14, the biochemical biomarker and histological analysis were determined. RESULTS: At 10 kGy, FRAP assays exhibited the highest antioxidant activity (380 mmol/kg). A significant inhibition of anti-biofilm activity was observed against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) (p<0.01). Fourteen days post-surgery, a significant reduction in thiobarbituric acid-reactive compounds (TBARs) was observed compared to the GEL-CH group. Concerning oxidative stress status, GEL-CH-Nigella significantly improved superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities. A histological analysis revealed that GEL-CH-Nigella accelerated wound closure and improved collagenisation and enhanced epidermal tissue thickness. CONCLUSIONS: These results indicate that GEL-CH-Nigella wound dressing is a promising biomaterial for engineered tissue.


Subject(s)
Antioxidants , Nigella sativa , Plant Oils , Animals , Rabbits , Antioxidants/pharmacology , Escherichia coli , Nigella sativa/chemistry , Staphylococcus aureus , Models, Animal , Skin , Plant Oils/pharmacology
2.
Water Sci Technol ; 80(7): 1226-1237, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31850874

ABSTRACT

We report the synthesis of hydroxyapatite (HAP) powder from waste mussel shells (decomposed to CaO) and phosphoric acid at room temperature without pH control. The powder synthesized was utilized for cadmium removal from aqueous solutions using the batch technique. The effects of solution pH, adsorbent dose; initial Cd2+ concentration, contact time, and temperatures were examined. Furthermore, the adsorption process revealed a pseudo-second-order reaction model and the Langmuir isotherm is the best-fit model to predict the experimental data and adsorption capacity was found to be 62.5 mg/g. Thermodynamic analysis revealed that because of the negative values of ΔGo and the positive value of ΔHo, the adsorption process was spontaneous and endothermic. Cadmium immobilization occurs through a two step mechanism: rapid ion exchange followed by partial dissolution of hydroxapatite and precipitation of cadmium containing hydroxyapatite.


Subject(s)
Bivalvia , Water Pollutants, Chemical , Adsorption , Animals , Cadmium , Durapatite , Hydrogen-Ion Concentration , Kinetics , Solutions , Temperature , Thermodynamics
3.
Mater Sci Eng C Mater Biol Appl ; 72: 650-658, 2017 Mar 01.
Article in English | MEDLINE | ID: mdl-28024634

ABSTRACT

Titania-Hydroxyapatite (TiO2/HAP) reinforced coatings are proposed to enhance the bioactivity and corrosion resistance of 316L stainless steel (316L SS). Herein, spin- and dip-coating sol-gel processes were investigated to construct two kinds of coatings: TiO2/HAP composite and TiO2/HAP bilayer. Physicochemical characterization highlighted the bioactivity response of the TiO2/HAP composite once incubated in physiological conditions for 7days whereas the TiO2/HAP bilayer showed instability and dissolution. Biological analysis revealed a failure in human stem cells adhesion on TiO2/HAP bilayer whereas on TiO2/HAP composite the presence of polygonal shaped cells, possessing good behaviour attested a good biocompatibility of the composite coating. Finally, TiO2/HAP composite with hardness up to 0.6GPa and elastic modulus up to 18GPa, showed an increased corrosion resistance of 316L SS. In conclusion, the user-friendly sol-gel processes led to bioactive TiO2/HAP composite buildup suitable for biomedical applications.


Subject(s)
Coated Materials, Biocompatible/chemistry , Durapatite/chemistry , Titanium/chemistry , Cell Adhesion/drug effects , Cell Proliferation/drug effects , Cells, Cultured , Coated Materials, Biocompatible/pharmacology , Corrosion , Cytoskeleton/drug effects , Electrochemical Techniques , Gels/chemistry , Hardness , Humans , Microscopy, Electron, Scanning , Spectrometry, X-Ray Emission , Stainless Steel/chemistry , Stem Cells/cytology , Stem Cells/drug effects , Stem Cells/metabolism , Umbilical Cord/cytology , X-Ray Diffraction
4.
Water Sci Technol ; 63(10): 2087-96, 2011.
Article in English | MEDLINE | ID: mdl-21977625

ABSTRACT

Carbonate hydroxyapatite (CHAP) was synthesized from different precursors; synthetic (CaCO3 and Ca(OH)2) and natural (egg shell before and after calcinations at 900 degrees C) under different conditions and characterized by using TG/DTG analysis, X-ray powder diffraction (XRD) method and Fourier transform infrared (FT-IR) spectroscopy techniques. The results of these analyses indicate that the four powders present the same structure of hydroxyapatite. Furthermore the four powders obtained were used for the retention of lead. The results obtained indicated that all powders present high adsorption capacity for lead, but from environmental and economic views, the hydroxyapatite synthesized from eggshell no calcined (HA2) is most advantageous. The influence of different sorption parameters, such as: initial metal concentration, equilibration time, solution pH and sorbent dosage was studied and discussed.


Subject(s)
Durapatite/chemical synthesis , Lead/isolation & purification , Water Pollutants, Chemical/isolation & purification , Adsorption , Hydrogen-Ion Concentration , Spectroscopy, Fourier Transform Infrared , Temperature , Thermogravimetry , X-Ray Diffraction
5.
J Hazard Mater ; 186(2-3): 1007-17, 2011 Feb 28.
Article in English | MEDLINE | ID: mdl-21159426

ABSTRACT

A factorial design was employed to evaluate the quantitative removal of zinc from aqueous solutions on synthesized hydroxyapatite. The experimental factors and their respective levels studied were the initial zinc concentration in solution (35≤C(Zn)≤85 mg/L), adsorbent dosage (4.5≤C(susp)≤9.5 g/L), Ca/P molar ratio (1.667≤Ca/P≤2) and calcination temperature of hydroxyapatite (600≤T(Cal)≤800 °C). The adsorption parameters were analysed statistically by means of variance analysis by using the STATISTICA software. The experimental results and statistical analysis show that increasing in the calcination temperature from 600 to 800 °C decrease the zinc adsorption whereas the increase of adsorbent dosage increases it. Based on the analysis of variance and the factorial design of experiments, adsorbent dosage has a positive effect on the removal of zinc, whereas zinc concentration, Ca/P molar ratio and calcination temperature have a negative effect on this process. The factorial results also demonstrate the existence of statistically significant binary interactions of the experimental factors. The experimental results were fitted to the Langmuir and Freundlich equations to find out adsorption capacities. In most cases, the results indicate that the sorption data fits well in the Freundlich isotherm model. The results of XRD analysis, pH(PZC) and pH(Final) values indicated that ion exchange and dissolution/precipitation mechanisms predominate for the sorption of zinc on our hydroxyapatite.


Subject(s)
Durapatite/chemistry , Zinc/chemistry , Adsorption , Algorithms , Analysis of Variance , Factor Analysis, Statistical , Indicators and Reagents , Industrial Waste/analysis , Kinetics , Spectroscopy, Fourier Transform Infrared , Temperature , Thermodynamics , Thermogravimetry , Waste Disposal, Fluid , X-Ray Diffraction
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