Melt‐blended halloysite nanotubes/wheat starch nanocomposites as drug delivery system

This article aims at preparing and characterizing efficiency of melt‐extruded polymer nanocomposites‐based drug delivery systems with tailored drug release properties. 5‐aminosalycylic acid (5‐ASA)‐loaded halloysite nanotubes (HNT)/plasticized starch nanocomposites were prepared and evaluated for the drug release, swelling characteristics, and degradability. The structure, morphology, and properties of the nanocomposites were characterized by using Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, and UV‐visible spectrophotometry. The 5‐ASA and HNT hybrid formation is confirmed, as well as the presence of 5‐ASA within the HNTs and an excellent dispersion of the 5‐ASA/HNT hybrid in the thermoplastic starch matrix. The swelling of nanocomposites strongly depends on the temperature but not on pH. The degradability tests yield a stabilized weight loss of 24 wt%, which is ascribed to leaching of plasticizers. The presence of HNTs delays the drug release process. The observed in vitro drug release after 2 h is 37.2% for plasticized starch and 30.0% for the nanocomposites. Overall results indicate that the developed nanocomposite system can be a potential candidate for drug delivery applications. POLYM. ENG. SCI., 55:573–580, 2015. © 2014 Society of Plastics Engineers     

Self‐aggregated nanoparticles of N‐dodecyl,N′‐glycidyl(chitosan) as pH‐responsive drug delivery systems for quercetin

In this study, pH‐responsive amphiphilic chitosan (CS) nanoparticles were used to encapsulate quercetin (QCT) for sustained release in cancer therapy. The novel CS derivatives were obtained by synthesis with 2,3‐epoxy‐1‐propanol, also known as glycidol, followed by acylation with dodecyl aldehyde. Characterization was performed by spectroscopic, viscosimetric, and size‐determination methods. Critical aggregation concentration, morphology, entrapment efficiency, drug release profile, cytotoxicity, and hemocompatibility studies were also carried out. The average size distribution of the self‐assembling nanoparticles measured by dynamic light scattering ranged from 140 to 300 nm. In vitro QCT release and Korsmeyer–Peppas model indicated that pH had a major role in drug release. Cytotoxicity assessments indicated that the nanoparticles were non‐cytotoxic. 3‐(4,5‐Dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide assay further revealed that QCT‐loaded nanoparticles could inhibit MCF‐7 cell growth. In vitro erythrocyte‐induced hemolysis indicated the good hemocompatibility of the nanoparticles. These results suggest that the synthesized copolymers might be potential carriers for hydrophobic drugs in cancer therapy. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45678.     

Remendable polymers via reversible Diels–Alder cycloaddition of anthracene‐containing copolymers with fullerenes

Poly(lauryl methacrylate)s with anthracene moieties in the side chain were converted with C₆₀‐fullerene and phenyl‐C₆₁‐butyric acid methyl ester (PCBM), resulting in new remendable (self‐healing) polymeric materials. The utilization of differently substituted anthracene monomers enabled the tuning of the reactivity and the resulting mechanical properties. Copolymers with different contents of the anthracene moieties were synthesized and characterized using size exclusion chromatography, ¹H nuclear magnetic resonance (NMR) spectroscopy as well as differential scanning calorimetry (DSC). ¹H NMR spectroscopic studies were utilized in order to investigate the reversibility of the Diels–Alder reaction between copolymers with C₆₀‐fullerene and PCBM, respectively, in solution. In order to investigate the conversion of the polymers with C₆₀‐fullerene and PCBM in bulk, additionally, DSC, nanoindentation, rheology, atomic force microscopy (AFM), 3D microscopy, simultaneous thermal analysis (STA) and FT‐Raman investigations were performed. The fullerene‐containing copolymers could be healed in a temperature range of 40–80 °C. Consequently, a new generation of low temperature remendable polymers could be established. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45916.     

Untersuchung von lokalen Schichtdickenverteilungen in Fluiden mithilfe der Nahinfrarot‐Bildanalyse

An online image analysis method to determine the film thickness in fluids by use of pulsed near infrared LEDs and an NIR camera was developed. This technique offers the possibility to monitor moving fluid layers. In this work the possibilities and limits of the used apparatus are demonstrated with the application example of measurement of the fluid film thickness distribution of water and glycerol in a falling film.     

Synthèse de copolymères multiséquencés comportant des séquences cristallines organosiliciques

Vinyl alcohol/vinyl propionate (VAL/VP) copolymers with different microstructure were prepared by two different methods, i.e. partial alkaline hydrolysis of poly(vinyl propionate) and by partial esterification of poly(vinyl alcohol). ¹³C-NMR results show that vinyl propionate units have an alternating tendency in VAL/VP copolymers prepared by esterification and a block distribution in VAL/VP copolymers when they are prepared by hydrolysis. The water absorption characteristics of VAP/VP copolymers have been studied. VAL/VP copolymers with a block sequence distribution exhibit a higher water absorption ability as compared with VAP/VP copolymers with a random sequence distribution and similar chemical composition. These results can be interpreted considering the formation of intramolecular hydrogen bondings as well as due also to steric hindrances effects. Sodium salicylate release studies from VAL/VP copolymers show that release is faster in VAL/VP copolymers prepared by hydrolysis according to its higher swelling ability in water.     

Produktionsintegrierter Umweltschutz – Verwertung von Reststoffen

Production-integrated environmental protection – Utilization of residues . Chemical plants as well as coal-fired powerstations utilize chemical reactions in order to produce materials or energy. Most of these reactions additionally produce gaseous, liquid, or solid residues. It is the main objective of production-integrated environmental protection to use these residues as suitable feedstocks in order to reduce environmental pollution and lower the consumption of raw materials. Several examples from the BASF Group will show how, by crossing the borders of the respective plant, reasonable solutions for material, or at least energetic, utilization of residues can be achieved. As a result of permanent efforts in production-integrated environmental protection over many years and despite increasing outputs the emissions of the chemical industry have been continuously reduced.     

Beef tallow biodiesel produced in a pilot scale

In the present work, the process of biodiesel production in a pilot plant has been studied using beef tallow as raw materials with methanol and potassium hydroxide as catalyst. The biodiesel quality is regulated by Brazilian specifications (Resolution 42) by the National Agency of Petroleum (ANP). The alkaline transesterification of animal fat with methanol produces a biodiesel with high quality and also with a good conversion rate. The process is possible but the economical viability must be improved by recovering methanol and glycerin. The obtained results have been used for industrial scale up of the process.     

The Consumption of Food Products from Linseed-Fed Animals Maintains Erythrocyte Omega-3 Fatty Acids in Obese Humans

Based on mechanistic and epidemiological data, we raise the question of the relationship between qualitative dietary polyunsaturated fatty acids (PUFA) changes and increase in obesity. In this double-blind trial, we studied the effects on 160 overweight volunteers (body mass index, BMI >30) of a 90 days experimental diet rich principally in animal fat with a low PUFA/saturated fatty acid (SFA) ratio but a low n-6/n-3 ratio, using animal products obtained from linseed-fed animals. The control diet provided less animal fat, a higher PUFA/SFA ratio and a higher n-6/n-3 ratio. Both diets excluded seafood. In the experimental group, we observed a significant increase in red blood cell (RBC) α-linolenic acid content and a slight increase in EPA and DHA derivatives, while in the control group we observed a significant reduction in EPA and DHA content. Between groups now, the difference in the three n-3 fatty acids changes in RBC was significant. This demonstrates that plasma EPA and DHA levels can be maintained without fish if products from linseed-fed animals are used. During the diets, we noted a significant reduction in weight, BMI and hip circumference within both groups of volunteers. However, no significant difference was observed between the control group and the experimental group. Interestingly, 150 days after the end of the trial (i.e., day 240), we noted a significant weight gain in the control group, whereas no significant weight gain was observed in the experimental group. This was also observed for the BMI and hip circumference. Moreover, significant differences in BMI (P < 0.05) and weight (P = 0.05) appeared between the two groups, showing in both cases a smaller increase in the experimental group. During the 90 days trial, we did not observe any differences between groups in terms of total cholesterol, HDL cholesterol, LDL cholesterol or triglycerides, suggesting that the saturate content and the P/S ratio are not as important as the n-6 and n-3 fatty acid composition.