Comparative Investigation of Cellular Effects of Polyethylene Glycol (PEG) Derivatives

Nowadays, polyethylene glycols referred to as PEGs are widely used in cosmetics, consumer care products, and the pharmaceutical industry. Their advantageous properties such as chemical stability, low immunogenicity, and high tolerability explain why PEGs are applied in many fields of pharmaceutical formulations including parenteral, topical, ophthalmic, oral, and rectal preparations and also in modern drug delivery systems. Given their extensive use, they are considered a well-known group of chemicals. However, the number of large-scale comparative studies involving multiple PEGs of wide molecular weight range is low, as in most cases biological effects are estimated upon molecular weight. The aim of this publication was to study the action of PEGs on Caco-2 cells and G. mellonella larvae and to calculate the correlation of these effects with molecular weight and osmolality. Eleven PEGs of different molecular weight were used in our experiments: PEG 200, PEG 300, PEG 400, PEG 600, PEG 1000, PEG 1500, PEG 4000, PEG 8000, PEG 10,000, 12,000, and PEG 20,000. The investigated cellular effects included cytotoxicity (MTT and Neutral Red assays, flow cytometry with propidium iodide and annexin V) and autophagy. The osmolality of different molecular weight PEGs with various concentrations was measured by a vapor pressure osmometer OSMOMAT 070 and G. mellonella larvae were injected with the solutions of PEGs. Sorbitol was used as controls of the same osmolality. Statistical correlation was calculated to describe the average molecular weight dependence of the different measured effects. Osmolality, the cytotoxicity assays, flow cytometry data, and larvae mortality had significant correlation with the structure of the PEGs, while autophagosome formation and the proportion of early apoptotic cells showed no statistical correlation. Overall, it must be noted that PEGs must be tested individually for biological effects as not all effects can be estimated by the average molecular weight.

Extraction optimisation and lipid-lowering activity of Auricularia heimuer polysaccharides

Assessments of molecular weight distribution and activity/efficacy of Auricularia heimuer polysaccharides (AAP) are of substantial significance for its extraction process optimisation. In the present study, single-factor orthogonal test and response surface methodology were employed to optimise extraction conditions of AAP. Furthermore, a rat hyperlipidaemia model was established to compare the lipid-lowering activity of polysaccharides obtained by three extraction methods. Conditions for enzymatic hydrolysis were optimised as pH 5.0, 1% cellulase, 2.5% substrate concentration and enzymolysis time of 1.5 h, leading to an up to 31.8% polysaccharide yield and 89.13% of polysaccharides within the molecular weight range of 5 000 Da to 10 000 Da. The results of animal experiments showed that the lipid-lowering activity of enzymolysis-extracted polysaccharides was significantly higher than that of water- and ultrasonic-extracted ones (P < 0.01). So the present study revealed that enzymatic hydrolysis-extracted polysaccharides showed the strongest hypolipidaemia activity, providing a basis for the development of A. heimuer-based functional foods and drugs.

Comparison of supercritical fluid extraction and thermal desorption methods for analysing organic compounds in house-dust

<p>This study has been focused on the comparison of the application of Thermal Desorption (TD) and Supercritical Fluid Extraction (SFE) methods for the identification and quantification of organic chemicals in house dust samples. To investigate how the results obtained by SFE and TD of house dust compare to one another and whether the SFE has advantages over the TD method, an aliquot of a house dust sample has been subjected to desorption at successively increasing temperatures. The thermal desorption unit used cryo - focusing on capillary tubing and was connected to a GC-MS combination. A quantity of the same house dust sample was extracted, using a method consisting of a two-step SFE with CO2 and CO2 + 5% of methanol, and GC-MS analysis of the eluates. The comparison of the results showed that the SFE method was superior to the TD for analysing indoor dust samples because of the pre-separation and the absence of thermal degradation, particularly for compounds of low volatility. However, TD could be more appropriate for relatively volatile or lower molecular weight range compounds and thermally stable compounds.</p>

Adaptation of the two-dimensional electrophoresis method for canned meat

Studies of the qualitative indicators of canned meat in accordance with regulatory documents are carried out on average samples of specimens, but when studying by proteomic methods, such sampling does not allow high-quality separation of protein components due to the high fat content in the product. When two-dimensional electrophoresis was carried out on an average sample, fragments of the main muscle and connective tissue proteins of beef were found in small quantities, but the electrophoretogram was not very informative. A significantly better separation was achieved after removing the fat fraction from the product. When studying broth from canned meat, the largest amount of intensely coloured high-molecular-weight protein fractions with a mass of more than 50 kDa was revealed. The electrophoretogram of the meat pieces showed a wide range of proteins across the entire molecular weight range of the polyacrylamide gel, including major muscle proteins. The study of broth together with meat pieces but after fat removal is optimal for the primary screening of the protein component of canned meat.

Exploring Protein Composition in Stickwater From Tuna by-products Processing as a Preliminary Approach for the Recovery of a Low Molecular Weight Fraction With Potential Algicidal Activity

The use of by-products for fishmeal production is constantly rising. During this process, stickwater is generated, an effluent that contains organic matter in soluble, colloidal or particulate form. It has been shown that stickwater contains an important amount of protein and that its characterization is the first step into achieving its full valorization. Tuna canning by-product´s stickwater was centrifuged and fractionated by ultrafiltration to bring awareness to its protein quality. Stickwater had a net protein content of 61.4%, centrifuged stickwater maintained a similar protein content meanwhile the protein content in ultrafiltered fractions decreased as their molecular weight range decreased as well. Stickwater, centrifuged stickwater and the fraction R10 presented gel-like characteristics that could position this effluent as a potential source of gelatin. The electrophoretic profile of stickwater, centrifuged stickwater and centrifuged solids demonstrated that a high amount of protein in stickwater was soluble. This first glance at protein/peptides from tuna canning by-products is part of the ongoing effort to propose their recovery an alternative and sustainable use of a fish processing effluent with potential application as a source of peptides with algicidal bioactivity against harmful algal blooms (HABs).

Biochemical and Functional Characterization of Kidney Bean Protein Alcalase-Hydrolysates and Their Preservative Action on Stored Chicken Meat

A new preservation approach is presented in this article to prolong the lifetime of raw chicken meat and enhance its quality at 4 °C via coating with highly soluble kidney bean protein hydrolysate. The hydrolysates of the black, red, and white kidney protein (BKH, RKH, and WKH) were obtained after 30 min enzymatic hydrolysis with Alcalase (E/S ratio of 1:100, hydrolysis degree 25–29%). The different phaseolin subunits (8S) appeared in SDS-PAGE in 35–45 kD molecular weight range while vicilin appeared in the molecular weight range of 55–75 kD. The kidney bean protein hydrolysates have considerable antioxidant activity as evidenced by the DPPH-scavenging activity and β-carotine-linolenic assay, as well as antimicrobial activity evaluated by disc diffusion assay. BKH followed by RKH (800 µg/mL) significantly (p ≤ 0.05) scavenged 95, 91% of DPPH and inhibited 82–88% of linoleic oxidation. The three studied hydrolysates significantly inhibited the growth of bacteria, yeast, and fungi, where BKH was the most performing. Kidney bean protein hydrolysates could shield the chicken meat because of their amphoteric nature and many functional properties (water and oil-absorbing capacity and foaming stability). The quality of chicken meat was assessed by tracing the fluctuations in the chemical parameters (pH, met-myoglobin, lipid oxidation, and TVBN), bacterial load (total bacterial count, and psychrophilic count), color parameters and sensorial traits during cold preservation (4 °C). The hydrolysates (800 µg/g) significantly p ≤ 0.05 reduced the increment in meat pH and TVBN values, inhibited 59–70% of lipid oxidation as compared to control during 30 days of cold storage via eliminating 50% of bacterial load and maintained secured storage for 30 days. RKH and WKH significantly (p ≤ 0.05) enhanced L*, a* values, thus augmented the meat whiteness and redness, while, BKH increased b* values, declining all color parameters during meat storage. RKH and WKH (800 µg/g) (p ≤ 0.05) maintained 50–71% and 69–75% of meat color and odor, respectively, increased the meat juiciness after 30 days of cold storage. BKH, RKH and WKH can be safely incorporated into novel foods.

Characterization of Kacang Goat skin Pepsin Soluble Collagen (Psc) and Their Potency as an Antioxidant

Collagen have been interesting material for many utilization such as food, pharmaceutical and cosmetic in various products and target administration, consequently collagen should be prepared as well as type of application. The objective of this research is to prepare collagen from goat skin and investigate the character and their potency as an antioxidant. Kacang goat skin aged 2 years was used for collagen production. Small slice skin was extracted by curing with 0.1% (w/v) pepsin in acetic acid 0.5 M, for 24, 48, dan 72 h at 4°C. The variables observed were molecular weight by Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS PAGE), microstructure using scanning electron microscope, thermal stability by differential scanning calorimetric, and the antioxidant potency through 2,2-diphenyl-1-picrylhydrazyl (DPPH) inhibition analysis. The result showed the molecular weight range from 25 kDa to 180 kDa, microstructure showed the collagen fibril crosslink, collagen start to denature at 62,28°C, highest dissolved with 1% NaCl concentration and has highest DPPH inhibition at 60 min after hydrolysis. In conclusion, kacang goat skin collagen prepared by pepsin in acetic acid.

Co-Cultivation of Two Bacillus Strains for Improved Cell Growth and Enzyme Production to Enhance the Degradation of Aflatoxin B1

Bacillus sp. H16v8 and Bacillus sp. HGD9229 were identified as Aflatoxin B1 (AFB1) degrader in nutrient broth after a 12 h incubation at 37 °C. The degradation efficiency of the two-strain supernatant on 100 μg/L AFB1 was higher than the bacterial cells and cell lysate. Moreover, degradations of AFB1 were strongly affected by the metal ions in which Cu2+ stimulated the degradation and Zn2+ inhibited the degradation. The extracellular detoxifying enzymes produced by co-cultivation of two strains were isolated and purified by ultrafiltration. The molecular weight range of the detoxifying enzymes was 20–25 kDa by SDS-PAGE. The co-culture of two strains improved the total cell growth with the enhancement of the total protein content and detoxifying enzyme production. The degradation efficiency of the supernatant from mixed cultures increased by 87.7% and 55.3% compared to Bacillus sp. H16v8 and HGD9229, individually. Moreover, after the degradation of AFB1, the four products of the lower toxicity were identified by LC-Triple TOF-MS with the two proposed hypothetical degradation pathways.

SCIENTIFIC AND TECHNOLOGICAL FEATURES OF SYNTHESIS OF NEW ESTER PLASTICIZERS BASED ON RENEWABLE RAW MATERIALS

Methods for the synthesis of ester non-toxic biodegradable plasticizers (hazard class 4) using renewable raw materials have been developed: glycerine-containing waste generated in the production of biofuels; citric acid 244, by microbial synthesis from molasses sugar production waste; polyatomic alcohol (neopoliol) – trimethylolpropane – a product of oxosynthesis obtained on the basis of natural gas. The target products are esters with a molecular weight range of 250-600, with low saturated vapor pressure, good thermal stability and polymer compatibility, and chemical inertia. The results of complex researches of processes of esterification of carboxylic acids with hydroxyl compounds in industrial homogeneous catalysts of different acidity (sulfuric acid, p-toluensulfonate, phosphoric acid) allowed determining the main approaches to the selection of raw materials chemical composition. This took into account the availability and toxicological characteristics and evaluation of the technological characteristics of esterification process to increase the conversion of raw materials and achieve a high selectivity for the target product. It is shown that to overcome the thermodynamic limitation in all processes, it is necessary to use a 6-7-fold molar excess of the second reagent: acid or alcohol. A solvent (benzene, toluene) is added to the initial mixture, which maintains a constant temperature and removes the reaction water in the form of an azeotrope. To isolate the target products from the reaction mass, it is proposed to use a film evaporator operating under vacuum (p=5-10 mm Hg, t=105-120 ℃). Samples of tributyrin glycerin, triamyl citrate and triethanoate purity ≥ 98% were obtained. The main physical-chemical properties were determined. A comparison with known industrial analogues was carried out. Evaluation of key quality indicators confirms the possibility of their use as plasticizers in the formulation of PVC pastes.

Progressive Cellular Architecture in Microscale Gas Chromatography for Broad Chemical Analyses

Gas chromatography is widely used to identify and quantify volatile organic compounds for applications ranging from environmental monitoring to homeland security. We investigate a new architecture for microfabricated gas chromatography systems that can significantly improve the range, speed, and efficiency of such systems. By using a cellular approach, it performs a partial separation of analytes even as the sampling is being performed. The subsequent separation step is then rapidly performed within each cell. The cells, each of which contains a preconcentrator and separation column, are arranged in progression of retentiveness. While accommodating a wide range of analytes, this progressive cellular architecture (PCA) also provides a pathway to improving energy efficiency and lifetime by reducing the need for heating the separation columns. As a proof of concept, a three-cell subsystem (PCA3mv) has been built; it incorporates a number of microfabricated components, including preconcentrators, separation columns, valves, connectors, and a carrier gas filter. The preconcentrator and separation column of each cell are monolithically implemented as a single chip that has a footprint of 1.8 × 5.2 cm2. This subsystem also incorporates two manifold arrays of microfabricated valves, each of which has a footprint of 1.3 × 1.4 cm2. Operated together with a commercial flame ionization detector, the subsystem has been tested against polar and nonpolar analytes (including alkanes, alcohols, aromatics, and phosphonate esters) over a molecular weight range of 32–212 g/mol and a vapor pressure range of 0.005–231 mmHg. The separations require an average column temperature of 63–68 °C within a duration of 12 min, and provide separation resolutions >2 for any two homologues that differ by one methyl group.