scholarly journals Chitosan Hydrogels for Chondroitin Sulphate Controlled Release: An Analytical Characterization

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Annalisa Bianchera ◽  
Enrico Salomi ◽  
Matteo Pezzanera ◽  
Elisabeth Ruwet ◽  
Ruggero Bettini ◽  
...  
Keyword(s):  
Controlled Release ◽  
Chondroitin Sulphate ◽  
Sem Analysis ◽  
Uv Spectrophotometry ◽  
Analytical Characterization ◽  
Feret Diameter ◽  
Chitosan Scaffolds ◽  
Chitosan Hydrogels

This paper provides an analytical characterization of chitosan scaffolds obtained by freeze-gelation toward the uptake and the controlled release of chondroitin sulphate (CS), as cartilage repair agent, under different pH conditions. Scanning electron microscopy (SEM), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and liquid chromatography-UV spectrophotometry (LC-UV) techniques were exploited to obtain qualitative and quantitative descriptions of polymer and drug behaviour in the biomaterial. As for morphology, SEM analysis allowed the evaluation of scaffold porosity in terms of pore size and distribution both at the surface (Feret diameter58±19 μm) and on the cross section (Feret diameter106±51 μm). LC and ATR-FTIR evidenced a pH-dependent CS loading and release behaviour, strongly highlighting the role of electrostatic forces on chitosan/chondroitin sulphate interactions.

Analytical Characterization of the Aroma of Five Premium Red Wines. Insights into the Role of Odor Families and the Concept of Fruitiness of Wines

2007 ◽  
Vol 55 (11) ◽  
pp. 4501-4510 ◽  
Author(s):  
Ana Escudero ◽  
Eva Campo ◽  
Laura Fariña ◽  
Juan Cacho ◽  
Vicente Ferreira
Keyword(s):  
Red Wines ◽  
Analytical Characterization

scholarly journals Analytical Characterization of the Role of Phospholipids in Platelet Adhesion and Secretion

2014 ◽  
Vol 87 (1) ◽  
pp. 413-421 ◽  
Author(s):  
Secil Koseoglu ◽  
Audrey F. Meyer ◽  
Donghyuk Kim ◽  
Ben M. Meyer ◽  
Yiwen Wang ◽  
...  
Keyword(s):  
Platelet Adhesion ◽  
Analytical Characterization

Biodegradable Chitosan Scaffolds: Effect of Genipin Crosslinking

2014 ◽  
Vol 805 ◽  
pp. 116-121 ◽  
Author(s):  
Greyce Yane Honorato Sampaio ◽  
Ana C.B.M. Fook ◽  
Thiago Bizerra Fideles ◽  
M.E.R.R.M. Cavalcanti ◽  
Marcus Vinícius Lia Fook
Keyword(s):  
Crosslinking Agent ◽  
Three Dimensional ◽  
Microstructural Characterization ◽  
Sem Analysis ◽  
Absorption Capacity ◽  
Dimensional Structure ◽  
Porous Architecture ◽  
Chitosan Scaffolds ◽  
2D And 3D

Currently researchers has pointed chitosan as one of the viable alternatives for application as scaffolds in tissue regeneration, mainly due to its availability, biocompatibility, biodegradability and ability to chemical modifications, among them, the crosslinking. With the growing number of investigations of crosslinking agents from natural sources and its applicability, this work focuses on the development and microstructural characterization of chitosan scaffolds and chitosan crosslinked with genipina using the technique of freeze drying. Solutions were prepared with chitosan concentration of 2% (w / t), and genipin 0.15% (w / t) and 0.3% (w / t). These were frozen at-20 ° C and ≈ 196 ° C, and lyophilized. The effect of different concentrations of genipin and freezing rates of the solutions in the porous architecture of the scaffolds were evaluated by Scanning Electron Microscopy (SEM), Optical Digital Microscopy 2D and 3D (OM) and testing the Degree of Swelling (DS). The SEM analysis revealed the formation of a three dimensional structure with pores and / or channels interconnected, influenced by the freezing rate and addition of crosslinking agent, these variables also influence the absorption capacity of the scaffolds. It was observed by OM, the effectiveness of the crosslinking with genipin, through points of fluorescence presented.

scholarly journals Injectable Chitosan Scaffolds with Calcium β-Glycerophosphate as the Only Neutralizing Agent

Processes ◽  
2019 ◽  
Vol 7 (5) ◽  
pp. 297 ◽  
Author(s):  
Piotr Owczarz ◽  
Anna Rył ◽  
Marek Dziubiński ◽  
Jan Sielski
Keyword(s):  
Calcium Ions ◽  
Sol Gel ◽  
Sem Analysis ◽  
Sodium Ions ◽  
Colloidal Solutions ◽  
Crosslinking Process ◽  
Chitosan Scaffolds ◽  
Neutralizing Agent ◽  
Gel Phase ◽  
Chitosan Hydrogels

The presented work describes the method of preparation of thermosensitive chitosan hydrogels using calcium β-glycerophosphate salt as the only pH neutralizing agent and supporting the crosslinking process. The presence of calcium ions instead of sodium ions is particularly important in the case of scaffolds in bone tissue engineering. Rheological and physicochemical properties of low concentrated chitosan solutions with the addition of calcium β-glycerophosphate were investigated using rotational rheometry techniques, Zeta potential (by electrophoresis), XPS, and SEM analysis together with an EDS detector. It was found to be possible to prepare colloidal solutions of chitosan containing only calcium β-glycerophosphate (without sodium ions) undergoing a sol-gel phase transition at the physiological temperature of the human body. It has also been shown that it is possible to further enrich the obtained cellular scaffolds with calcium ions. Using the addition of calcium carbonate, hydrogels with a physiological ratio of calcium to phosphorus (1.6–1.8):1 were obtained.

scholarly journals Colored Polymeric Microcomposites with Minimal Environmental Impact

2017 ◽  
Vol 54 (3) ◽  
pp. 418-422
Author(s):  
Mircea Ruse ◽  
Sandu Peretz ◽  
Anca Angela Athanasiu ◽  
Loti Cornelia Oproiu ◽  
Catalin Filipescu ◽  
...  
Keyword(s):  
Controlled Release ◽  
Natural Fibers ◽  
Sem Analysis ◽  
Cotton Wool ◽  
Colorimetric Analysis ◽  
Ph Variation ◽  
Vis Spectroscopy ◽  
Ft Ir ◽  
Minimal Environmental Impact

The paper presents the research carried out by our team on achieving amphiphilic polymeric microcomposites, colored in ruby and violet shades for natural fibers dyeing (cotton, wool). The colored polymeric microcomposites were characterized in term of their morpholo- gical (by optical microscopy and SEM analysis) and physicochemical performancies (by FT-IR and UV-Vis spectroscopy, colorimetric analysis). The colored microcapsules were tested by studying the controlled release of the encapsulated dyes in water, to pH variation. This study was necessary to the coloristic characterization of colored polymeric microcomposites to determine the optimal microcapsules dye concentration and dyeing concentration of natural fibers.

Characterization of biogenic organic matter (BOM)

1998 ◽  
Vol 37 (2) ◽  
pp. 97-103 ◽  
Author(s):  
Fritz H. Frimmel ◽  
Jutta Jahnel ◽  
Sebastian Hesse
Keyword(s):  
Organic Matter ◽  
Hydrological Cycle ◽  
Complex Structure ◽  
Aquatic Systems ◽  
Refractory Part ◽  
Analytical Characterization ◽  
Small Variety ◽  
Water Constituents

Biogenic organic matter (BOM) is of ubiquitous relevance in all aquatic systems. This is due to the fundamental function of the natural organic matter in combination with the microbial activity which guarantees the degradation in and the self purification of water in the hydrological cycle. In addition, the refractory part of the widely distributed BOM acts as effective adsorbent for most water constituents, and in case of mobile fractions as active vehicle for pollutants. In contrast to the broad importance of the occurrence and role of BOM, there is a fairly small variety for its analytical characterization. Especially in the field of in-situ measurements and of the determination in the original concentration range of aqueous samples, relatively little data have been collected. This is partly due to the complex structure of BOM, partly to the limited availability of analytical methods suited for that type of investigations. The aim of the paper is to give typical examples for the a) physical/chemical, b) microbiological and c) technologically orientated methods of the analytical characterization of BOM in aqueous solution and to draw conclusions on the function of BOM in aquatic systems and their use for man.

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