Silybin-Functionalized PCL Electrospun Fibrous Membranes for Potential Pharmaceutical and Biomedical Applications.

Silybin is a natural flavonolignan with potential anticancer, antioxidant, and hepatoprotective properties. In the present study, various loadings of silybin (1, 3, and 5 wt%) were encapsulated in poly-ε-caprolactone (PCL) fibers by electrospinning, in order to produce new pharmaceutical composites with improved bioactive and drug delivery properties. The morphological characteristics of the composite fibrous structures were evaluated by scanning electron microscopy (SEM), and the encapsulation efficiency and the release rate of silybin were quantified using a UV-Vis spectrophotometer.

Desolvation Inability of Solid Hydrates, an Alternative Expression for the Gibbs Free Energy of Solvation, and the Myth of Freeze-Drying.

The term "desolvation inability" is proposed in order to describe the alteration of the original chemical structure of a solute ("decomposition") prior to the solvent's full removal upon the heating of the solvate. This behavior has been sporadically reported; however, it is much more frequent, and it is the basis of various, seemingly unrelated, effects/processes, e.g.

Simulation and Experimental Study of the Isothermal Thermogravimetric Analysis and the Apparent Alterations of the Thermal Stability of Composite Polymers.

Composite polymers are an interesting class of materials with a wide range of applications. Among the properties of polymers which are currently being enhanced via the development of composite materials is their thermal stability, which is typically evaluated via thermogravimetric analysis (TGA). In this work, a paradox is recognized regarding the considered relationship between the polymer-filler interactions leading to a good dispersion of the filler and the improvement of thermal stability.

Cellulose Acetate-Ionic Liquid Blends as Potential Polymers for Efficient CO Separation Membranes.

CO capture, applied in CO separation from natural gas or in CO/N separation from power plant flue gas streams, is of great importance for technical, economic, and environmental reasons. The latter seems important because CO, as a greenhouse gas, is considered the main contributor to global warming. Using polymeric membranes for CO separation presents several advantages, such as low energy demand, small equipment volume, and the absence of liquid waste.

Properties Optimization of Polypropylene/Montmorillonite Nanocomposite Drawn Fibers.

In this study, the mechanical properties and thermal stability of composite polypropylene (PP) drawn fibers with two different organically modified montmorillonites were experimentally investigated and optimized using a response surface methodology. Specifically, the Box-Behnken Design of Experiments method was used in order to investigate the effect of the filler content, the compatibilizer content, and the drawing temperature on the tensile strength and the onset decomposition temperature of the PP composite drawn fibers. The materials were characterized by tensile tests, thermogravimetry, and X-ray diffraction.

Thermodynamic and Vibrational Aspects of Peptide Bond Hydrolysis and Their Potential Relationship to the Harmfulness of Infrared Radiation.

The primary physicochemical effect upon exposure to infrared radiation (IR) is the temperature increase of cells. The degradation of proteins via the hydrolysis of peptide bonds is related to cell malfunction. In this work, the degradation of proteins/peptides under the influence of IR radiation is theoretically studied.

Thermal Behavior of Poly(vinyl alcohol) in the Form of Physically Crosslinked Film.

Evaluation and understanding of the thermal behavior of polymers is crucial for many applications, e.g., polymer processing at relatively high temperatures, and for evaluating polymer-polymer miscibility.

Thermochemical Transition in Non-Hydrogen-Bonded Polymers and Theory of Latent Decomposition.

Although thermosets and various biopolymers cannot be softened without being decomposed, the vast majority of thermoplastics are believed to exhibit thermal transitions solely related to physical alterations of their structure-a behavior typical of low molecular weight substances. In this study, Differential Scanning Calorimetry (DSC), Fourier Transform Infrared Spectroscopy (FTIR) and Thermogravimetry (TGA) were used to study the softening of four common non-hydrogen-bonded thermoplastic polymers (polypropylene, polypropylene-grafted-maleic anhydride, poly(vinyl chloride) and polystyrene) along with a hydrogen-bonded polymer as a reference, namely, poly(vinyl alcohol). It is shown that the softening of these polymers is a thermochemical transition.

On the Thermodynamic Thermal Properties of Quercetin and Similar Pharmaceuticals.

The thermodynamic properties of pharmaceuticals are of major importance since they are involved in drug design, processing, optimization and modelling. In this study, a long-standing confusion regarding the thermodynamic properties of flavonoids and similar pharmaceuticals is recognized and clarified. As a case study, the thermal behavior of quercetin is examined with various techniques.

Thermochemical Transition in Low Molecular Weight Substances: The Example of the Silybin Flavonoid.

Silybin is a complex organic molecule with high bioactivity, extracted from the plant Silybum. As a pharmaceutical substance, silybin's bioactivity has drawn considerable attention, while its other properties, e.g.

On the Thermochemical Transition Depression of Cellulose Acetate Composite Membranes.

Gallic acid (GA) and quercetin (QU) are two important bioactive molecules with increased biomedical interest. Cellulose acetate (CA) is a polymer derived from cellulose and is used in various applications. In this work, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) were used to study the thermal behavior of electrospun CA membranes loaded with quercetin or gallic acid.

Surface Response Analysis for the Optimization of Mechanical and Thermal Properties of Polypropylene Composite Drawn Fibers with Talc and Carbon Nanotubes.

A large portion of the produced Polypropylene (PP) is used in the form of fibers. In this industrially oriented study, the development of composite PP drawn fibers was investigated. Two types of fillers were used (ultra-fine talc and single-wall carbon nanotubes).

Optimization of Thermal and Mechanical Properties of Polypropylene-Wollastonite Composite Drawn Fibers Based on Surface Response Analysis.

The thermal and mechanical properties of polypropylene-wollastonite composite drawn fibers were optimized via experiments selected with the Box-Behnken approach. The drawing ratio, the filler and the compatibilizer content were chosen as design variables, while the tensile strength, the melting enthalpy and the onset decomposition temperature were set as response variables. Drawn fibers with tensile strength up to 535 MPa were obtained.

SpAD Biofunctionalized Cellulose Acetate Scaffolds Inhibit Adherence in a Coordinating Function with the von Willebrand A1 Domain (vWF A1).

is one of the major pathogens causing and spreading hospital acquired infections. Since it is highly resistant to new generation antibiotics, novel strategies have to be developed such as the construction of biofunctionalized non-adherent surfaces that will prevent its tethering and subsequent spread in the hospital environment. In this frame, the domain D of protein A (SpAD) of has been immobilized onto cellulose acetate scaffolds by using the streptavidin/biotin interaction, in order to study its interaction with the A1 domain of von Willebrand factor (vWF A1), a protein essential for hemostasis, found in human plasma.

Experimental Investigation of Polypropylene Composite Drawn Fibers with Talc, Wollastonite, Attapulgite and Single-Wall Carbon Nanotubes.

Isotactic polypropylene (PP) composite drawn fibers were prepared using melt extrusion and high-temperature solid-state drawing at a draw ratio of 7. Five different fillers were used as reinforcement agents (microtalc, ultrafine talc, wollastonite, attapulgite and single-wall carbon nanotubes). In all the prepared samples, antioxidant was added, while all samples were prepared with and without using PP grafted with maleic anhydride as compatibilizer.

Glass chemical transition: An unknown thermal transition observed in cellulose acetate butyrate.

Cellulose acetate butyrate (CAB) belongs to cellulose esters, an important category of polymers, that are derived from the most abundant organic substance on earth (cellulose). As most cellulose esters, CAB is believed to exhibit a melting point. In this study, carefully selected experiments were performed, in order to test if the endothermic peak, observed in the Differential Scanning Calorimetry (DSC) scan of CAB, is a melting point.

Enhancement of the performance of a combined microalgae-activated sludge system for the treatment of high strength molasses wastewater.

The treatment of molasses wastewater, by a combined microalgae-activated sludge process, for the simultaneous organics and total nitrogen reduction, was examined. Further enhancement of the performance of the combined process was accomplished, by means of biofilm carriers or electrocoagulation. A LED light tube was immersed into the reactor tank aiming to enhance the growth of photosynthetic microalgae, while in a similar unit, biofilm carriers were added to the system, representing a moving bed bioreactor.

Microalgae-activated sludge treatment of molasses wastewater in sequencing batch photo-bioreactor.

The aim of this work was the examination of the treatment potential of molasses wastewater, by the utilization of activated sludge and microalgae. The systems used included a sequencing batch bioreactor and a similar photo-bioreactor, favoring microalgae growth. The microalgae treatment of molasses wastewater mixture resulted in a considerable reduction in the total nitrogen content.

Biodegradation and decolorization of melanoidin solutions by manganese peroxidase yeasts.

The ability of selected manganese peroxidase (MnP) yeast strains, isolated from the mixed liquor of an activated sludge bioreactor treating melanoidins wastewater, was investigated in this work, aiming to examine the degradation potential of melanoidins, in the presence or absence of nutrients. Ten yeast strains were initially isolated from the mixed liquor; four yeast strains (Y1, Y2, Y3 and Y4) were selected for further studies, based on their tolerance towards synthetic melanoidins (SMs) degradation and MnP activity onto solid agar medium. The Y1 strain exhibited almost 98% homology to Candida glabrata yeast, based on 28S rRNA identification studies.

Selective extraction of oxygenated compounds from oregano with sub-critical water.

Background: The essential oil of oregano is composed of numerous substances that exhibit various properties (e.g. antioxidants).

Equation-of-state modeling of mixtures with ionic liquids.

A non-electrolyte equation-of-state model was used to describe the phase behavior of binary systems containing alkyl-methyimidazolium bis(trifluoromethyl-sulfonyl)imide ionic liquids. A methodology is suggested for modeling this phase behavior by using the Non-Random Hydrogen-Bonding (NRHB) model. According to this methodology, the scaling constants of the ionic liquid are calculated using limited available experimental data on liquid densities and Hansen's solubility parameters, while all electrostatic interactions (polar, hydrogen bonding and ionic) are treated as strong specific interactions.