scholarly journals Surface Functionalization of Bioactive Glasses with Polyphenols from Padina pavonica Algae and In Situ Reduction of Silver Ions: Physico-Chemical Characterization and Biological Response

Coatings ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 394 ◽  
Author(s):  
Asmaa Sayed Abdelgeliel ◽  
Sara Ferraris ◽  
Andrea Cochis ◽  
Sara Vitalini ◽  
Marcello Iriti ◽  
...  
Keyword(s):  
Bone Healing ◽  
Antibacterial Agents ◽  
Biological Response ◽  
Chemical Characterization ◽  
Silver Ions ◽  
Biological Behavior ◽  
In Situ Reduction ◽  
Bioactive Glasses ◽  
Physico Chemical

Bioactive glasses (BGs) are attractive materials for bone replacement due to their tailorable chemical composition that is able to promote bone healing and repair. Accordingly, many attempts have been introduced to further improve BGs’ biological behavior and to protect them from bacterial infection, which is nowadays the primary reason for implant failure. Polyphenols from natural products have been proposed as a novel source of antibacterial agents, whereas silver is a well-known antibacterial agent largely employed due to its broad-ranged activity. Based on these premises, the surface of a bioactive glass (CEL2) was functionalized with polyphenols extracted from the Egyptian algae Padina pavonica and enriched with silver nanoparticles (AgNPs) using an in situ reduction technique only using algae extract. We analyzed the composite’s morphological and physical-chemical characteristics using FE-SEM, EDS, XPS and Folin–Ciocalteau; all analyses confirmed that both algae polyphenols and AgNPs were successfully loaded together onto the CEL2 surface. Antibacterial analysis revealed that the presence of polyphenols and AgNPs significantly reduced the metabolic activity (>50%) of Staphylococcus aureus biofilm in comparison with bare CEL2 controls. Finally, we verified the composite’s cytocompatibility with human osteoblasts progenitors that were selected as representative cells for bone healing advancement.

In situ reduction of antibacterial silver ions to metallic silver nanoparticles on bioactive glasses functionalized with polyphenols

2017 ◽  
Vol 396 ◽  
pp. 461-470 ◽  
Author(s):  
S. Ferraris ◽  
M. Miola ◽  
A. Cochis ◽  
B. Azzimonti ◽  
L. Rimondini ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Silver Ions ◽  
Metallic Silver ◽  
In Situ Reduction ◽  
Bioactive Glasses

scholarly journals Soil physico-chemical characterization in the different soil layers of National Maize Research Program, Rampur, Chitwan, Nepal

2018 ◽  
Vol 3 (1) ◽  
pp. 28-44
Author(s):  
Dinesh Khadka ◽  
Sushil Lamichhane ◽  
Amit P Timilsina ◽  
Bandhu R Baral ◽  
Kamal Sah ◽  
...  
Keyword(s):  
Research Program ◽  
Soil Structure ◽  
Sandy Loam ◽  
Chemical Properties ◽  
Single Layer ◽  
Chemical Characterization ◽  
Bottom Layer ◽  
Soil Parameters ◽  
Physico Chemical

Soil pit digging and their precise study is a decision making tool to assess history and future of soil management of a particular area. Thus, the present study was carried out to differentiate soil physico-chemical properties in the different layers of excavated pit of the National Maize Research Program, Rampur, Chitwan, Nepal. Eight pits were dug randomly from three blocks at a depth of 0 to 100 cm. The soil parameters were determined in-situ, and in laboratory for texture, pH, OM, N, P (as P2O5), K (as K2O), Ca, Mg, S, B, Fe, Zn, Cu and Mn of collected soils samples of different layers following standard analytical methods at Soil Science Division, Khumaltar. The result revealed that soil structure was sub-angular in majority of the layers, whereas bottom layer was single grained. The value and chrome of colour was increasing in order from surface to bottom in the majority pits. Similarly, the texture was sandy loam in majority layers of the pits. Moreover, four types of consistence (loose to firm) were observed. Furthermore, mottles and gravels were absent in the majority layers. Likewise, soil was very to moderately acidic in observed layers of majority pits, except bottom layer of agronomy block was slightly acidic. Regarding fertility parameters (OM, macro and micronutrients), some were increasing and vice-versa, while others were intermittent also. Therefore, a single layer is not dominant for particular soil physico-chemical parameters in the farm. In overall, surface layer is more fertile than rest of the layers in all the pits.     

scholarly journals Grafting of Gallic Acid onto a Bioactive Ti6Al4V Alloy: A Physico-Chemical Characterization

Coatings ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 302 ◽  
Author(s):  
Martina Cazzola ◽  
Sara Ferraris ◽  
Enrico Prenesti ◽  
Valentina Casalegno ◽  
Silvia Spriano
Keyword(s):  
Gallic Acid ◽  
Titanium Substrate ◽  
Biological Response ◽  
Chemical Characterization ◽  
Bone Contact ◽  
Oh Groups ◽  
Metal Implants ◽  
Functionalized Surfaces ◽  
Physico Chemical

Despite increasing interest in the use of natural biomolecules for different applications, few attempts of coupling them to inorganic biomaterials are reported in literature. Functionalization of metal implants with natural biomolecules could allow a local action, overcoming the issue of low bioavailability through systemic administration. In the present work, gallic acid was grafted to a pre-treated Ti6Al4V in order to improve its biological response in bone contact applications. The grafting procedure was optimized by choosing the concentration of gallic acid (1 mg/mL) and the solvent of the solution, which was used as a source for functionalization, in order to maximize the amount of the grafted molecule on the titanium substrate. The functionalized surfaces were characterized. The results showed that functionalization with Simulated Body Fluid (SBF) as solvent medium was the most effective in terms of the amount and activity of the grafted biomolecule. A key role of calcium ions in the grafting mechanism is suggested, involving the formation of coordination compounds formed by way of gallic acid carboxylate and Ti–O− as oxygenated donor groups. Bioactive behavior and surface charge of the pre-treated Ti6Al4V surface were conserved after functionalization. The functionalized surface exposed a greater amount of OH groups and showed higher wettability.

Titanium Carbide MXenes Mediated In Situ Reduction Allows Label-Free and Visualized Nanoplasmonic Sensing of Silver Ions

2020 ◽  
Vol 92 (6) ◽  
pp. 4623-4629 ◽  
Author(s):  
Yan Wang ◽  
Song Wang ◽  
Ningning Dong ◽  
Wenyuan Kang ◽  
Kun Li ◽  
...  
Keyword(s):  
Titanium Carbide ◽  
Silver Ions ◽  
Label Free ◽  
In Situ Reduction

scholarly journals Caractérisation physico-chimique des eaux d’un système lacustre du cordon littoral ivoirien : cas du lac Labion

2020 ◽  
Vol 14 (5) ◽  
pp. 1878-1892
Author(s):  
Ella Odjohou ◽  
Mireille Amani ◽  
Gbombélé Soro ◽  
Sylvain Monde
Keyword(s):  
Suspended Matter ◽  
Chemical Characterization ◽  
Principal Component ◽  
Temporal Analysis ◽  
Physico Chemical ◽  
Conductivité Électrique ◽  
Spatio Temporal ◽  
Pollution Mechanism

L’analyse spatio-temporelle des paramètres physico-chimiques des eaux du lac Labion dans le système lagunaire ivoirien, a été abordé dans un contexte de variabilité climatique. L’objectif est de caractériser la physico-chimie des eaux au cours des saisons climatiques. Pour y parvenir, une analyse hydrologique a été réalisé à partir de mesure in situ des paramètres pH, Température, Conductivité électrique, Oxygène dissous, Matières en suspension, Transparence et Turbidité. Ces paramètres ont été mesurés à l’aide d’un multi-paramètre. Celui-ci est mis à l’eau et les résultats s’affichent à l’écran. Seule la transparence a été mesuré à l’aide du disque de Secchi. La température (31 °C) indique des eaux relativement chaudes. Quant au pH, il varie du neutre (6,79) à alcalin (8,99). La conductivité moyenne sur le lac est de 40 μS/cm. Les eaux sont bien oxygénées (7 à 8 mg/L) et présente peu de matières en suspension. L’analyse en composante principale montre une forte corrélation (r > 0,7) entre les variables température, oxygène, pH et conductivité. Ces résultats mettent en évidence deux (02) mécanismes qui sont à l’origine des forçages naturel et artificiel. Il s’agit du mécanisme de la photosynthèse occasionnant une bonne oxygénation des eaux et du mécanisme de pollution traduisant une forte turbidité.Mots clés : Lac, saison climatique, paramètre, mécanisme, évolution.   English Title: Physico-chemical characterization of the waters of a lake system of the ivorian coastal cordon: case of Lake LabionThe spatio-temporal analysis of the physicochemical parameters of the waters of Lake Labion in the Ivorian lagoon system was tackled in the context of climate variability. The objective is to characterize the physico-chemistry of the waters during the climatic seasons. To achieve this, a hydrological analysis was carried out using in situ measurement of the parameters pH, Temperature, Electrical conductivity, Dissolved oxygen, Suspended matter, Transparency and Turbidity. These parameters were measured using a multi-parameter. It is launched and the results are displayed on the screen. Only transparency was measured using the Secchi disk. The temperature (31 °C) indicates relatively warm waters. As for the pH, it varies from neutral (6.79) to alkaline (8.99). The average conductivity on the lake is 40 μS / cm. The waters are well oxygenated (7 to 8 mg / L) and have little suspended matter. The principal component analysis shows a strong correlation (r> 0.7) between the variables temperature, oxygen, pH and conductivity. These results highlight two (02) mechanisms which are at the origin of natural and artificial forcings. This is the mechanism of photosynthesis causing good oxygenation of water and the pollution mechanism reflecting high turbidity.Keywords: Lake, climatic season, parameter, mechanism, evolution.

Physico-chemical characterization and biological response of Labeo rohita-derived hydroxyapatite scaffold

2013 ◽  
Vol 37 (7) ◽  
pp. 1233-1240 ◽  
Author(s):  
S. Mondal ◽  
A. Mondal ◽  
N. Mandal ◽  
B. Mondal ◽  
S. S. Mukhopadhyay ◽  
...  
Keyword(s):  
Labeo Rohita ◽  
Biological Response ◽  
Chemical Characterization ◽  
Physico Chemical ◽  
Hydroxyapatite Scaffold

Unique Trinuclear Ag(I)-N-Heterocyclic Carbene (NHC) Complex having Three Silver Centers: Synthesis and characterization

2020 ◽  
Vol 42 (3) ◽  
pp. 429-429
Author(s):  
Aqsa Habib Aqsa Habib ◽  
Haq Nawaz Bhatti Haq Nawaz Bhatti ◽  
Muhammad Adnan Iqbal and Muhammad Shahid Muhammad Adnan Iqbal and Muhammad Shahid
Keyword(s):  
Research Work ◽  
Silver Ions ◽  
Trinuclear Complex ◽  
Imidazolium Salt ◽  
New Approach ◽  
Metal Interactions ◽  
Physico Chemical ◽  
Metal Metal ◽  
Methyl Imidazole

The employment of carbene salts to facilitate metal-metal interactions is becoming a more pronounced zone of interest due to their efficient sigma electron donor features, facile synthesis protocols and their ability to develop strong ligand-metal interactions which may further be attributed to their flat steric factors. The research work discussed in this article was conducted to achieve this goal. Herein we report the synthesis of a novel trinuclear silver complex by a new approach. An imidazolium salt 2 was synthesized by in situ deprotonation and its trinuclear silver(I) complex 3 was synthesized by using initially controlled excess of precursor in order to understand the effect of excess of the selected reactant on complex formation. Both the ligand and complex were characterized by physico-chemical techniques. The results revealed the final product obtained was a trinuclear complex 3 having a core of three silver centres in a row, with the two distal silver ions bound to two carbene ligands and central one was bound by nitrogen of N-methyl imidazole. ESI-MS spectrum of compound 3 indicated that the complex chooses trinuclear structure in a solid and liquid state while in gas phase it appears as a mononuclear unit.

scholarly journals Characterizing Interstellar Medium, Planetary Surface and Deep Environments by Spectroscopic Techniques Using Unique Simulation Chambers at Centro de Astrobiologia (CAB)

Life ◽  
2019 ◽  
Vol 9 (3) ◽  
pp. 72
Author(s):  
Eva Mateo-Marti ◽  
Olga Prieto-Ballesteros ◽  
Guillermo Muñoz Caro ◽  
Cristobal González-Díaz ◽  
Victoria Muñoz-Iglesias ◽  
...  
Keyword(s):  
High Pressure ◽  
Interstellar Medium ◽  
Chemical Characterization ◽  
Physical Parameters ◽  
Spectroscopic Techniques ◽  
Experimental Systems ◽  
Physico Chemical ◽  
Potential Tool

At present, the study of diverse habitable environments of astrobiological interest has become a major challenge. Due to the obvious technical and economical limitations on in situ exploration, laboratory simulations are one of the most feasible research options to make advances both in several astrobiologically interesting environments and in developing a consistent description of the origin of life. With this objective in mind, we applied vacuum and high pressure technology to the design of versatile simulation chambers devoted to the simulation of the interstellar medium, planetary atmospheres conditions and high-pressure environments. These simulation facilities are especially appropriate for studying the physical, chemical and biological changes induced in a particular sample by in situ irradiation or physical parameters in a controlled environment. Furthermore, the implementation of several spectroscopies, such as infrared, Raman, ultraviolet, etc., to study solids, and mass spectrometry to monitor the gas phase, in our simulation chambers, provide specific tools for the in situ physico-chemical characterization of analogues of astrobiological interest. Simulation chamber facilities are a promising and potential tool for planetary exploration of habitable environments. A review of many wide-ranging applications in astrobiology are detailed herein to provide an understanding of the potential and flexibility of these unique experimental systems.

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