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In winemaking, sulfur dioxide addition is the most common procedure to prevent enzymatic and microbial alterations. However, the enological industry looks for safer alternatives to preserve enological products, and high-pressure treatments with supercritical CO2 are a suitable alternative. This study evaluates the effectiveness of this process in the stabilization and preservation of white grape must, studying the influence of time, pressure, and CO2 percentage on must characteristics. In spite of the percentage of CO2 turned out to be the variable that affects the most the process, no remarkable differences were observed in pH, acidity, and color intensity between untreated and treated musts. Moreover, this technique has proven to be very efficient in the reduction of aerobic mesophilic microorganisms as well as in the reduction of residual polyphenol oxidase activities, being lower than those obtained with SO2 addition (60 and 160 mg/L). Based on the results, the most convenient conditions were 100 bar and 10% CO2, for 10 min treatment. [ABSTRACT FROM AUTHOR]

The use of pharmacoactive polymeric devices has experienced significant growth in recent years due to their ability to increase the efficacy of treatment and acceptance by the body. Among the natural active principles, those recovered from waste from other industries stand out. In addition to participating in the circular economy, some of these by-products have very interesting properties to be used in biomedicine. However, the challenge in this field is to introduce these active principles into polymers in the most efficient and least polluting way possible. In this sense, one of the techniques with the greatest impact is the use of supercritical fluids. In this work, the supercritical impregnation of two biomedical polymers was studied comparatively: polylactic acid (PLA) and thermoplastic polyurethane (TPU). The impregnated active ingredient was Mangifera indica leaf extract (MLE), which has demonstrated antioxidant, antimicrobial, and anti-inflammatory capacities, and proangiogenic, antiproliferative, and anti-apoptotic effects on colony-forming endothelial cells. The results obtained expose the potential of the polymers studied in the field of biomedicine due to the acquired bioactivity of both polymers after the process, which was verified by measuring the antioxidant capacity. Better loads have been obtained in TPU compared to PLA. Both polymers exhibit diffusion-based release kinetics, in which a rapid release is observed in the early moments followed by a much slower release. However, PLA seems to release a greater proportion of its impregnated extract than TPU in less time, which is interesting to determine the different applications that each polymer can have. [ABSTRACT FROM AUTHOR]

Three-dimensional printing is a type of additive manufacturing of great interest in biomedical engineering. The production in situ of customized structures, tissues, implants, or other devices represents a great advance in this field. In addition, the use of polymers functionalized with bioactive substances that improve treatment represents even greater progress. One of these substances could be olive leaf extract (OLE), which has a wide variety of antioxidant compounds of interest for the treatment of heart, neurodegenerative, or oncological diseases. This work analyzes the use of supercritical impregnation of polylactic acid (PLA) filaments with an OLE for later use in a 3D printer. The effect of printing temperature (200, 210, and 220 ºC) and printing speed (40, 50, and 60 mm/s) was studied, using the antioxidant activity of the generated devices as a response variable. The results showed that both parameters were statistically significant and negative, an increase in these factors led to a decrease in antioxidant activity. [ABSTRACT FROM AUTHOR]

Supercritical fluid extraction (SFE), using CO2, is a novel, sustainable and very efficient technique for the recovery of highly apolar compounds. However, the recovery of phenolic compounds requires the use of different co-solvent combinations such as water and ethanol to enhance the recovery of these compounds through the optimization of a number of variables. In this sense, the effect of pressure (100, 150 and 200 bar), temperature (50, 65 and 80 °C), extraction time (30, 60, 90, 120, 150 and 180 min) and the effect of the different percentages of ethanol and water as co-solvents on the composition and phenolic content of moringa leaf extracts were evaluated. Six major flavonoids were identified by ultra-high-performance liquid chromatography coupled to a quadrupole-time-of-flight mass spectrometer (UHPLC-Q-ToF-MS). Pressure and temperature had a significant effect on the phenolic composition of the extracts, as well as on their concentrations. The highest concentration of total flavonoids compounds (TFCs) was obtained by using a mixture of CO2 and water of 50:50 (v/v) at 100 bar, at 65 °C after a 120 min extraction time that produced a concentration of 11.66 mg ± 0.02 mg TFC g−1 sample, which corresponds to 89.0% of the total flavonoids of the sample, obtained by exhaustive extraction. [ABSTRACT FROM AUTHOR]

Nuts are very important foods for human nutrition due to their high content of mono- and polyunsaturated fatty acids. However, they are substrates very sensitive to oxidation, appearing rancidity that affects both the taste and the smell, that led to the consumer's rejection. To avoid this, the food industry uses some strategies that sometimes substantially alter the composition and nutritional value of nuts. A promising possibility for the conservation and stability against its oxidation is to impregnate a natural antioxidant such as methyl gallate using CO2 in supercritical conditions. This technology is being used recently for the impregnation of different natural substances on polymers for its use in the food and biomedicine field. However, the direct supercritical impregnation of compounds into food has been scarcely investigated. In the present work, it is studied the effect of pressure and temperature in the impregnation process of methyl gallate on peeled peanuts. Additionally, the effect of the depressurization rate and impregnation time was studied at the most convenient conditions. The results obtained indicate the best conditions for impregnation were reached at 150 bar and 45 °C. These conditions improved the antioxidant capacity of the nuts while preserving the quality by avoiding breakages during the process. [ABSTRACT FROM AUTHOR]

The manufacture of functionalized bioabsorbable polymeric implants is gaining attention in recent years. These devices administer gradually and locally drugs or biomolecules to treat several diseases and they disappear once they perform their function. In this work, ketoprofen, an anti-inflammatory drug with analgesic and antipyretic effects, was loaded by supercritical solvent impregnation (SSI) in polylactic acid (PLA) filaments, and the initial stage of its in vitro release was explored. Impregnation experiments were carried out in a range of pressure and temperature of 25-40 MPa and 328-348 K. Different drug loading values were obtained (up to 9 % respecting the polymer mass) depending on the operating conditions.The ketoprofen release profile and the mathematical modelling (Korsmeyer-Peppas and Peppas-Sahlin models) showed an initial release governed by diffusion and with different kinetics depending on the impregnation conditions. Thus, this study reveals that SSI could be used to manufacture personalized drug-delivery implants based on the final dose and required dosing rate. [ABSTRACT FROM AUTHOR]

Epidemiological studies reveal that metabolic disorders, and specifically type 2 diabetes (T2D), are relevant risk factors to develop Alzheimer's disease (AD) and vascular dementia (VaD), the most common causes of dementia. AD patients are in a tremendous need of new therapeutic options because of the limited success of available treatments. Natural polyphenols, and concretely Mangifera indica Linn extract (MGF), have been reported to have antiinflammatory, antioxidant and antidiabetic activities. The role of MGF in central complications associated with T2D, after long-term treatment of db/db mice with MGF was analyzed. Metabolic parameters (body weight, glucose and insulin levels) as well as central complications including brain atrophy, inflammatory processes, spontaneous bleeding, tau phosphorylation and cognitive function in db/db mice treated with MGF for 22 weeks were assessed. MGF limits body weight gain in obese db/db mice. Insulin and C-peptide levels, indicative of pancreatic function, were longer maintained in MGF-treated animals. MGF reduced central inflammation by lowering microglia burden, both in the cortex and the hippocampus. Likewise, central spontaneous bleeding was significantly reduced in db/db mice. Cortical and hippocampal atrophy was reduced in db/db mice and tau hyperphosphorylation was lower after MGF treatment, resulting in partial recovery of learning and memory disabilities. Altogether, the data suggested that MGF treatment may provide a useful tool to target different aspects of AD and VaD pathology, and could lead to more effective clinical therapies for the prevention of metabolic related central complications associated with AD and VaD. [ABSTRACT FROM AUTHOR]