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1.
Int J Biol Macromol ; : 132186, 2024 May 07.
Artículo en Inglés | MEDLINE | ID: mdl-38723815

RESUMEN

Trigonella foenum-graecum, known as fenugreek, belongs to the leguminous family of wild growth in Western Asia, Europe, the Mediterranean, and Asia; its ripe seeds contain a pool of bioactive substances with great potential in the food industry and medicine. In this study, fenugreek seed mucilage (FSM) was extracted and characterized in its structural properties by X-ray diffraction, nuclear magnetic resonance, and high-performance liquid chromatography. Then, the applicability of FSM as an antimicrobial agent was demonstrated via the development of novel, active, edible FSM-based biofilms containing carboxymethyl cellulose and rosemary essential oil (REO). Incorporating REO in the biofilms brought about specific changes in Fourier-transform infrared spectra, affecting thermal degradation behavior. Scanning electron microscopy and atomic force microscopy morphography showed an even distribution of REO and smoother surfaces in the loaded films. Besides, the solubility tests evidenced a reduction in water solubility with increasing REO concentration from 1 to 3 wt%. The biological assay evidenced the antimicrobial activity of REO-loaded biofilms against Staphylococcus aureus and Escherichia coli. Finally, whole apples were dip-coated with FSM-based solutions to showcase future edible systems. The REO-loaded biofilms extended the shelf life of apples to 30 days, demonstrating their potential for sustainable and active coatings.

2.
Heliyon ; 10(3): e24770, 2024 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-38322905

RESUMEN

Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is a promising biodegradable bio-based material, which is designed for a vast range of applications, depending on its composite. This study aims to assess the degradability of a PHBV-based compound under different conditions. The research group followed different methodological approaches and assessed visual and mass changes, mechanical and morphological properties, spectroscopic and structural characterisation, along with thermal behaviour. The Ph-Stat (enzymatic degradation) test and total dry solids (TDS)/total volatile solids (TVS) measurements were carried out. Finally, the team experimentally evaluated the amount of methane and carbon dioxide produced, i.e., the degree of biodegradation under aerobic conditions. According to the results, different types of tests have shown differing effects of environmental conditions on material degradation. In conclusion, this paper provides a summary of the investigations regarding the degradation behaviour of the PHBV-based compound under varying environmental factors. The main strengths of the study lie in its multi-faceted approach, combining assessments of PHBV-based compound degradability under different conditions using various analytical tools, such as visual and mass changes, mechanical and morphological properties, spectroscopic and structural characterization, and thermal behavior. These methods collectively contribute to the robustness and reliability of the undertaken work.

3.
Sci Rep ; 14(1): 3663, 2024 02 13.
Artículo en Inglés | MEDLINE | ID: mdl-38351239

RESUMEN

Mining has led to severe environmental pollution in countries with exhaustive mining production and inadequate industrial waste regulation. Microorganisms in contaminated sites, like mine tailings, have adapted to high concentrations of heavy metals, developing the capacity of reducing or removing them from these environments. Therefore, it is essential to thoroughly characterize bacteria present in these sites to find different ways of bioremediation. In this regard, in this study, an enrichment and isolation procedure were performed to isolate bacteria with lower nutritional requirements and high tolerance to Cu(II) and Fe(II) from two Sonoran River basin mining tails. Two Staphylococcus species and a Microbacterium ginsengisoli strain were isolated and identified from the San Felipe de Jesús mining tail. Also, three strains were isolated from the Nacozari de García mining tail: Burkholderia cenocepacia, Sphingomonas sp. and Staphylococcus warneri. Significant microbiological differences were found between the two sites. All these species exhibited tolerance up to 300 mg/L for Cu (II)-Fe (II) solutions, indicating their capacity to grow in these conditions. Moreover, a consortium of isolated bacteria was immobilized in two different biocomposites and the biocomposite with larger pore size achieved greater bacterial immobilization showcasing the potential of these bacteria in biotechnological applications.


Asunto(s)
Metales Pesados , Contaminantes del Suelo , Metales Pesados/análisis , Residuos Industriales/análisis , Minería , Biodegradación Ambiental , Bacterias , Contaminantes del Suelo/análisis
4.
Polymers (Basel) ; 15(22)2023 Nov 14.
Artículo en Inglés | MEDLINE | ID: mdl-38006128

RESUMEN

Recently, piezoresistive sensors made by 3D printing have gained considerable interest in the field of wearable electronics due to their ultralight nature, high compressibility, robustness, and excellent electromechanical properties. In this work, building on previous results on the Selective Laser Sintering (SLS) of porous systems based on thermoplastic polyurethane (TPU) and graphene (GE)/carbon nanotubes (MWCNT) as carbon conductive fillers, the effect of variables such as thickness, diameter, and porosity of 3D printed disks is thoroughly studied with the aim of optimizing their piezoresistive performance. The resulting system is a disk with a diameter of 13 mm and a thickness of 0.3 mm endowed with optimal reproducibility, sensitivity, and linearity of the electrical signal. Dynamic compressive strength tests conducted on the proposed 3D printed sensors reveal a linear piezoresistive response in the range of 0.1-2 N compressive load. In addition, the optimized system is characterized at a high load frequency (2 Hz), and the stability and sensitivity of the electrical signal are evaluated. Finally, an application test demonstrates the ability of this system to be used as a real-time wearable pressure sensor for applications in prosthetics, consumer products, and personalized health-monitoring systems.

5.
Biomacromolecules ; 24(11): 5277-5289, 2023 11 13.
Artículo en Inglés | MEDLINE | ID: mdl-37890135

RESUMEN

Genetic engineering allows fine-tuning and controlling protein properties, thus exploiting the new derivatives to obtain novel materials and systems with improved capacity to actively interact with biological systems. The elastin-like polypeptides are tunable recombinant biopolymers that have proven to be ideal candidates for realizing bioactive interfaces that can interact with biological systems. They are characterized by a thermoresponsive behavior that is strictly related to their peculiar amino acid sequence. We describe here the rational design of a new biopolymer inspired by elastin and the comparison of its physicochemical properties with those of another already characterized member of the same protein class. To assess the cytocompatibility, the behavior of cells of different origins toward these components was evaluated. Our study shows that the biomimetic strategy adopted to design new elastin-based recombinant polypeptides represents a versatile and valuable tool for the development of protein-based materials with improved properties and advanced functionality.


Asunto(s)
Biomimética , Elastina , Elastina/química , Adhesión Celular , Péptidos/farmacología , Péptidos/química , Secuencia de Aminoácidos , Biopolímeros/química
6.
J Colloid Interface Sci ; 652(Pt B): 1308-1324, 2023 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-37659303

RESUMEN

HYPOTHESIS: Implementation of tissue adhesives from natural sources endowed with good mechanical properties and underwater resistance still represents a challenging research goal. Inspired by the extraordinary wet adhesion properties of mussel byssus proteins resulting from interaction of catechol and amino residues, hydrogels from soy protein isolate (SPI) and selected polyphenols i.e. caffeic acid (CA), chlorogenic acid (CGA) and gallic acid (GA) under mild aerial oxidative conditions were prepared. EXPERIMENTS: The hydrogels were subjected to chemical assays, ATR FT-IR and EPR spectroscopy, rheological and morphological SEM analysis. Mechanical tests were carried out on hydrogels prepared by inclusion of agarose. Biological tests included evaluation of the antibacterial and wound healing activity, and hemocompatibility. FINDINGS: The decrease of free NH2 and SH groups of SPI, the EPR features, the good cohesive strength and excellent underwater resistance (15 days for SPI/GA) under conditions relevant to their use as surgical glues indicated an efficient interaction of the polyphenols with the protein in the hydrogels. The polyphenols greatly also improved the mechanical properties of the SPI/ agarose/polyphenols hydrogels. These latter proved biocompatible, hemocompatible, not harmful to skin, displayed durable adhesiveness and good water-vapour permeability. Excellent antibacterial properties and in some cases (SPI/CGA) a favourable wound healing activity on dermal fibroblasts was obtained.

7.
Antioxidants (Basel) ; 12(5)2023 Apr 25.
Artículo en Inglés | MEDLINE | ID: mdl-37237859

RESUMEN

Dry eye disease (DED) is a dynamic and complex disease that can cause significant damage to the ocular surface and discomfort, compromising the patient's quality of life. Phytochemicals such as resveratrol have received increasing attention due to their ability to interfere with multiple pathways related to these diseases. However, the low bioavailability and the poor therapeutic response of resveratrol hinder its clinical applications. Cationic polymeric nanoparticles, in combination with in situ gelling polymers, could represent a promising strategy to prolong drug corneal residence time reducing the frequency of administration and increasing the therapeutic response. Eyedrop formulations, based on acetylated polyethyleneimine-modified polylactic-co-glicolyc acid- (PLGA-PEI) nanoparticles loaded with resveratrol (RSV-NPs) were dispersed into poloxamer 407 hydrogel and characterized in terms of pH, gelation time, rheological properties, in vitro drugs release, and biocompatibility. Moreover, the antioxidant and anti-inflammatory effects of RSV were assessed in vitro by mimicking a DED condition through the exposition of epithelial corneal cells to a hyperosmotic state. This formulation exhibited sustained release of RSV for up to 3 days, exerting potent antioxidant and anti-inflammatory effects on corneal epithelial cells. In addition, RSV reversed the mitochondrial dysfunction mediated by high osmotic pressure, leading to upregulated sirtuin-1 (SIRT1) expression, an essential regulator of mitochondrial function. These results suggest the potential of eyedrop formulation as a platform to overcome the rapid clearance of current solutions for treating various inflammation- and oxidative stress-related diseases such as DED.

8.
Nanomaterials (Basel) ; 13(5)2023 Feb 23.
Artículo en Inglés | MEDLINE | ID: mdl-36903701

RESUMEN

A straightforward, low-cost, and scalable solid-state mechanochemical protocol for the synthesis of silver nanoparticles (AgNP) based on the use of the highly reducing agri-food by-product pecan nutshell (PNS) is reported herein. Under optimized conditions (180 min, 800 rpm, PNS/AgNO3 ratio = 55/45 w/w), a complete reduction in silver ions was achieved, leading to a material containing ca. 36% w/w Ag0 (X-ray diffraction analysis). Dynamic light scattering and microscopic analysis showed a uniform size distribution (15-35 nm average diameter) of the spherical AgNP. The 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay revealed lower-although still absolutely high (EC50 = 5.8 ± 0.5 mg/mL)-antioxidant properties for PNS for the further incorporation of AgNP, supporting the efficient reduction of Ag+ ions by PNS phenolic compounds. Photocatalytic experiments indicated that AgNP-PNS (0.4 mg/mL) was able to induce the >90% degradation of methylene blue after 120 min visible light irradiation, with good recycling stability. Finally, AgNP-PNS demonstrated high biocompatibility and significantly light-enhanced growth inhibition properties against Pseudomonas aeruginosa and Streptococcus mutans at concentrations as low as 250 µg/mL, also eliciting an antibiofilm effect at 1000 µg/mL. Overall, the adopted approach allowed to reuse a cheap and abundant agri-food by-product and required no toxic or noxious chemicals, making AgNP-PNS a sustainable and easy-to-access multifunctional material.

9.
Polymers (Basel) ; 15(6)2023 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-36987214

RESUMEN

The goal of this work was to investigate the morphological and chemical-physical changes induced by adding ZnO nanoparticles to bio-based polymeric materials based on polylactic acid (PLA) and polyamide 11 (PA11). Precisely, the photo- and water-degradation phenomena of nanocomposite materials were monitored. For this purpose, the formulation and characterization of novel bio-nanocomposite blends based on PLA and PA11 at a ratio of 70/30 wt.% filled with zinc oxide (ZnO) nanostructures at different percentages were performed. The effect of ZnO nanoparticles (≤2 wt.%) within the blends was thoroughly explored by employing thermogravimetry (TGA), size exclusion chromatography (SEC), matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and scanning and transmission electron microscopy (SEM and TEM). Adding up to 1% wt. of ZnO resulted in a higher thermal stability of the PA11/PLA blends, with a decrement lower than 8% in terms of molar masses (MMs) values being obtained during blend processing at 200 °C. ZnO promoted trans-ester-amide reactions between the two polymers, leading to the formation of PLA/PA11 copolymers. These species could work as compatibilisers at the polymer interface, improving thermal and mechanical properties. However, the addition of higher quantities of ZnO affected such properties, influencing the photo-oxidative behaviour and thus thwarting the material's application for packaging use. The PLA and blend formulations were subjected to natural aging in seawater for two weeks under natural light exposure. The 0.5% wt. ZnO sample induced polymer degradation with a decrease of 34% in the MMs compared to the neat samples.

10.
J Funct Biomater ; 14(2)2023 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-36826881

RESUMEN

Atopic dermatitis (AD) is a common disease-causing skin inflammation, redness, and irritation, which can eventually result in infection that drastically impacts patient quality of life. Resveratrol (Res) is a natural phytochemical famed for its excellent anti-inflammatory and antioxidant activities. However, it is poorly bioavailable. Thus, a drug delivery system is needed to enhance in vivo bioactivity. Herein, we report the preparation of hyaluronic acid (HA) hydrogels containing resveratrol-loaded chitosan (CS) nanoparticles, their physicochemical analysis, and their potential therapeutic effects in the treatment of AD. Positively charged CS nanoparticles prepared by tripolyphosphate (TPP) gelation showed sizes ranging from 120 to around 500 nm and Res encapsulation efficiency as high as 80%. Embedding the nanoparticles in HA retarded their hydrolytic degradation and also slowed resveratrol release. Resveratrol released from nanoparticle-loaded hydrogel counteracted the oxidative damage induced by ROS generation in TNF-α/INF-γ-treated human keratinocytes (HaCaT) used as an AD in vitro model. Moreover, pre-treatment with Res@gel reduced secretion and gene expression of proinflammatory cytokines in HaCaT cells. The physicochemical analysis and in vitro assay confirmed that the formulated hydrogel could be considered an efficient and sustained resveratrol delivery vector in AD treatment.

11.
Polymers (Basel) ; 14(24)2022 Dec 17.
Artículo en Inglés | MEDLINE | ID: mdl-36559900

RESUMEN

The use of lignocellulose-rich biowaste as reinforcing filler in biodegradable polymers represents a sustainable option to obtain cost-effective bio-based materials to be used for several applications. In addition, the scarce polymer-biofiller interaction can be improved by reactive functionalization of the matrix. However, the obtained biocomposites might show high thermal deformability and possibly a slow biodegradation rate. In this work, polylactic acid (PLA) was first chemically modified with itaconic anhydride, and then biocomposites containing 50 wt.% of pecan (Carya illinoinensis) nutshell (PNS) biowaste were prepared and characterized. Their physical and morphological properties were determined, along with their biodegradation behavior in soil. Moreover, the effects of two environmentally friendly physical treatments, namely ball-milling of the filler and thermal annealing on biocomposites, were assessed. Grafting increased PLA thermal-oxidative stability and crystallinity. The latter was further enhanced by the presence of PNS, achieving a 30% overall increase compared to the plain matrix. Accordingly, the biocomposites displayed mechanical properties comparable to those of the plain matrix. Thermal annealing dramatically increased the mechanical and thermomechanical properties of all materials, and the heat deflection temperature of the biocomposites dramatically increased up to 60 °C with respect to the non-annealed samples. Finally, PNS promoted PLA biodegradation, triggering the swelling of the composites under soil burial, and accelerating the removal of the polymer amorphous phase. These results highlight the potential of combining natural fillers and environmentally benign physicochemical treatments to tailor the properties of PLA biocomposites. The high biofiller content used in this work, in conjunction with the chemical and physico-mechanical treatments applied, increased the thermal, mechanical, and thermomechanical performance of PLA biocomposites while improving their biodegradation behavior. These outcomes allow for widening the application field of PLA biocomposites in those areas requiring a stiff and lightweight material with low deformability and faster biodegradability.

12.
ACS Appl Polym Mater ; 4(10): 7191-7203, 2022 Oct 14.
Artículo en Inglés | MEDLINE | ID: mdl-36277172

RESUMEN

The introduction of inorganic materials into biopolymers has been envisioned as a viable option to modify the optical and structural properties of these polymers and promote their exploitation in different application fields. In this work, the growth of Al2O3 in freestanding ∼30-µm-thick poly(butylene succinate) (PBS) films by sequential infiltration (SIS) at 70 °C via trimethylaluminum (TMA) and H2O precursors was investigated for the first time. The incorporation of Al2O3 into the PBS matrix was clearly demonstrated by XPS analysis and SEM-EDX cross-sectional images showing a homogeneous Al2O3 distribution inside the PBS films. Raman measurements on infiltrated freestanding PBS show a reduction of the signal related to the ester carbonyl group as compared to pristine freestanding PBS films. Accordingly, FTIR and NMR characterization highlighted that the ester group is involved in polymer-precursor interaction, leading to the formation of an aliphatic group and the concomitant rupture of the main polymeric chain. Al2O3 mass uptake as a function of the number of SIS cycles was studied by infiltration in thin PBS films spin-coated on Si substrates ranging from 30 to 70 nm. Mass uptake in the PBS films was found to be much higher than in standard poly(methyl methacrylate) (PMMA) films, under the same process conditions. Considering that the density of reactive sites in the two polymers is roughly the same, the observed difference in Al2O3 mass uptake is explained based on the different free volume of these polymers and the specific reaction mechanism proposed for PBS. These results assessed the possibility to use SIS as a tool for the growth of metal oxides into biopolymers, paving the way to the synthesis of organic-inorganic hybrid materials with tailored characteristics.

13.
Polymers (Basel) ; 14(12)2022 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-35745971

RESUMEN

Edible polymers such as polysaccharides, proteins, and lipids are biodegradable and biocompatible materials applied as a thin layer to the surface of food or inside the package. They enhance food quality by prolonging its shelf-life and avoiding the deterioration phenomena caused by oxidation, humidity, and microbial activity. In order to improve the biopolymer performance, antimicrobial agents and plasticizers are also included in the formulation of the main compounds utilized for edible coating packages. Secondary natural compounds (SC) are molecules not essential for growth produced by some plants, fungi, and microorganisms. SC derived from plants and fungi have attracted much attention in the food packaging industry because of their natural antimicrobial and antioxidant activities and their effect on the biofilm's mechanical properties. The antimicrobial and antioxidant activities inhibit pathogenic microorganism growth and protect food from oxidation. Furthermore, based on the biopolymer and SC used in the formulation, their specific mass ratio, the peculiar physical interaction occurring between their functional groups, and the experimental procedure adopted for edible coating preparation, the final properties as mechanical resistance and gas barrier properties can be opportunely modulated. This review summarizes the investigations on the antimicrobial, mechanical, and barrier properties of the secondary natural compounds employed in edible biopolymer-based systems used for food packaging materials.

14.
Int J Biol Macromol ; 200: 350-361, 2022 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-34998889

RESUMEN

Biodegradable polymer composites reinforced with agri-food lignocellulosic biowaste represent cost-effective and sustainable materials potentially able to replace traditional composites for structural, household, and packaging applications. Herein, the preparation of polylactic acid (PLA)/pecan (Carya illinoinensis) nutshell (PNS) biocomposites at high filler loading (50 wt%) is reported, alongside the effect of two environmentally friendly physical treatments, namely ball-milling of the filler and thermal annealing on biocomposites. PNS enhanced the thermal stability, the viscoelastic response, and the crystallinity of the polymer. Furthermore, filler ball-milling also increased the melt fluidity of the biocomposites, potentially improving melt processing. Finally, the presence of PNS remarkably enhanced the effect of thermal annealing in the compounds. In particular, heat deflection temperature of the biocomposites dramatically increased, up to 60 °C with respect to the non-annealed samples. Overall, these results emphasize the potential of combining natural fillers and environmentally benign physical treatments to tailor the properties of PLA biocomposites, especially for those applications which require a stiff and lightweight material with low deformability.


Asunto(s)
Poliésteres
15.
Front Cell Infect Microbiol ; 11: 702676, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34490142

RESUMEN

Clinical manifestations of leishmaniasis range from self-healing, cutaneous lesions to fatal infections of the viscera. With no preventative Leishmania vaccine available, the frontline option against leishmaniasis is chemotherapy. Unfortunately, currently available anti-Leishmania drugs face several obstacles, including toxicity that limits dosing and emergent drug resistant strains in endemic regions. It is, therefore, imperative that more effective drug formulations with decreased toxicity profiles are developed. Previous studies had shown that 2-(((5-Methyl-2-thienyl)methylene)amino)-N-phenylbenzamide (also called Retro-2) has efficacy against Leishmania infections. Structure-activity relationship (SAR) analogs of Retro-2, using the dihydroquinazolinone (DHQZ) base structure, were subsequently described that are more efficacious than Retro-2. However, considering the hydrophobic nature of these compounds that limits their solubility and uptake, the current studies were initiated to determine whether the solubility of Retro-2 and its SAR analogs could be enhanced through encapsulation in amphiphilic polymer nanoparticles. We evaluated encapsulation of these compounds in the amphiphilic, thermoresponsive oligo(ethylene glycol) methacrylate-co-pentafluorostyrene (PFG30) copolymer that forms nanoparticle aggregates upon heating past temperatures of 30°C. The hydrophobic tracer, coumarin 6, was used to evaluate uptake of a hydrophobic molecule into PFG30 aggregates. Mass spectrometry analysis showed considerably greater delivery of encapsulated DHQZ analogs into infected cells and more rapid shrinkage of L. amazonensis communal vacuoles. Moreover, encapsulation in PFG30 augmented the efficacy of Retro-2 and its SAR analogs to clear both L. amazonensis and L. donovani infections. These studies demonstrate that encapsulation of compounds in PFG30 is a viable approach to dramatically increase bioavailability and efficacy of anti-Leishmania compounds.


Asunto(s)
Leishmania , Leishmaniasis , Animales , Disponibilidad Biológica , Leishmaniasis/tratamiento farmacológico , Ratones , Ratones Endogámicos BALB C , Polímeros
16.
Molecules ; 26(9)2021 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-34066573

RESUMEN

Herein, smart coatings based on photo-responsive polymer nanocapsules (NC) and deposited by laser evaporation are presented. These systems combine remotely controllable release and high encapsulation efficiency of nanoparticles with the easy handling and safety of macroscopic substrates. In particular, azobenzene-based NC loaded with active molecules (thyme oil and coumarin 6) were deposited through Matrix-Assisted Pulsed Laser Evaporation (MAPLE) on flat inorganic (KBr) and organic (polyethylene, PE) and 3D (acrylate-based micro-needle array) substrates. SEM analyses highlighted the versatility and performance of MAPLE in the fabrication of the designed smart coatings. DLS analyses, performed on both MAPLE- and drop casting-deposited NC, demonstrated the remarkable adhesion achieved with MAPLE. Finally, thyme oil and coumarin 6 release experiments further demonstrated that MAPLE is a promising technique for the realization of photo-responsive coatings on various substrates.

17.
Molecules ; 27(1)2021 Dec 31.
Artículo en Inglés | MEDLINE | ID: mdl-35011469

RESUMEN

The release of pharmaceutical wastewaters in the environment is of great concern due to the presence of persistent organic pollutants with toxic effects on environment and human health. Treatment of these wastewaters with microorganisms has gained increasing attention, as they can efficiently biodegrade and remove contaminants from the aqueous environments. In this respect, bacterial immobilization with inorganic nanoparticles provides a number of advantages, in terms of ease of processing, increased concentration of the pollutant in proximity of the cell surface, and long-term reusability. In the present study, MCM-41 mesoporous silica nanoparticles (MSN) were immobilized on a selected bacterial strain to remove alprazolam, a persistent pharmaceutical compound, from contaminated water. First, biodegrading microorganisms were collected from pharmaceutical wastewater, and Pseudomonas stutzeri was isolated as a bacterial strain showing high ability to tolerate and consume alprazolam as the only source for carbon and energy. Then, the ability of MSN-adhered Pseudomonas stutzeri bacteria was assessed to biodegrade alprazolam using quantitative HPLC analysis. The results indicated that after 20 days in optimum conditions, MSN-adhered bacterial cells achieved 96% biodegradation efficiency in comparison to the 87% biodegradation ability of Pseudomonas stutzeri freely suspended cells. Kinetic study showed that the degradation process obeys a first order reaction. In addition, the kinetic constants for the MSN-adhered bacteria were higher than those of the bacteria alone.


Asunto(s)
Alprazolam/química , Biodegradación Ambiental , Residuos Industriales , Nanopartículas , Pseudomonas stutzeri/metabolismo , Aguas Residuales/química , Aguas Residuales/microbiología , Alprazolam/metabolismo , Humanos , Cinética , Nanotecnología , Filogenia , Pseudomonas stutzeri/clasificación , Pseudomonas stutzeri/genética , Pseudomonas stutzeri/aislamiento & purificación , ARN Ribosómico 16S , Termodinámica
18.
Polymers (Basel) ; 12(10)2020 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-33050501

RESUMEN

Compression molded biodegradable films based on poly(butylene succinate) (PBS) and poly(butylene adipate-co-terephthalate) (PBAT) at varying weights were prepared, and their relevant properties for packaging applications are here reported. The melt rheology of the blends was first studied, and the binary PBS/PBAT blends exhibited marked shear thinning and complex thermoreological behavior, due to the formation of a co-continuous morphology in the 50 wt% blend. The films were characterized by infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), mechanical tensile tests, scanning electron microscopy (SEM), and oxygen and water vapor permeability. PBS crystallization was inhibited in the blends with higher contents of PBAT, and FTIR and SEM analysis suggested that limited interactions occur between the two polymer phases. The films showed increasing stiffness as the PBS percentage increased; further, a sharp decrease in elongation at break was noticed for the films containing percentages of PBS greater than 25 wt%. Gas permeability decreased with increasing PBS content, indicating that the barrier properties of PBS can be tuned by blending with PBAT. The results obtained point out that the blend containing 25 wt% PBS is a good compromise between elastic modulus (135 MPa) and deformation at break (390%) values. Overall, PBS/PBAT blends represent an alternative for packaging films, as they combine biodegradability, good barrier properties and reasonable mechanical behavior.

19.
Nanomaterials (Basel) ; 10(9)2020 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-32911815

RESUMEN

Thermo-responsive copolymers based on oligo(ethylene glycol) methacrylate (OEGMA, Mn = 300 g/mol) and pentafluorostyrene (PFS), coded PFG, were synthesized by RAFT polymerization, using a trithiocarbonate (CTTPC) as controlling agent. Different molar masses were targeted and dispersities lower than 1.51 were obtained. The thermally triggered self-assembly of the resulting PFG copolymers in water was investigated by dynamic light scattering (DLS). The lower critical solution temperature (LCST) slightly increased with the molecular weight in the 26-30 °C temperature range, whereas the sizes of the intermicellar aggregates formed upon self-assembly tended to decrease with increasing molecular weights (ranging from 1415 to 572 nm). The resulting thermally-induced polymer aggregates were then used to encapsulate and remove organic contaminants from water. Nile Red (NR) and Thiazole yellow G (TYG) were employed as hydrophobic and hydrophilic model contaminants, respectively. Experimental results evidenced that higher molecular weight copolymers removed up to 90% of NR from aqueous solution, corresponding to about 10 mg of dye per g of copolymer, regardless of NR concentration. The removal of TYG was lower with respect to NR, decreasing from about 40% to around 20% with TYG concentration. Finally, the copolymers were shown to be potentially recycled and reused in the treatment of contaminated water.

20.
J Complement Integr Med ; 18(2): 279-285, 2020 Sep 21.
Artículo en Inglés | MEDLINE | ID: mdl-32950964

RESUMEN

OBJECTIVES: The Phytomedicine (PM) and Food supplements (FS) Market is considerably growing in Morocco a review of state is necessarily to structure and improve it. METHODS: Information was collected directly from the pharmacist through a questionnaire-based survey who was conducted in 284 pharmacies in the region of Fez-Meknes in Morocco. Data were analyzed and classified using relative frequency of citations (RFC). RESULTS: More than 98% of the pharmacies commercialized the PM and FS, 80% of the pharmacists deny the existence of a real area dedicated to them, the majority (94%) of them prefer phytomedicine rather than classic drugs. This study reported about 64 products as the most used by the population of the region of Fez-Meknes among them 48 FS (75%) and 16 PM (25%) and the most marketed products are used for Transit Disorders (28.34%), then Anxiety (22.17%) and ENT Disease (20.18%). CONCLUSIONS: Despite the fact that Morocco is a country where people use medicinal plants daily, the commercialization of the PM and FS is still unstructured. Due to legal problem the PM Sold in the market are mainly exported. To assure development and also valorization of this sector the regulation of this market is highly required.


Asunto(s)
Plantas Medicinales , Suplementos Dietéticos , Humanos , Mercadotecnía , Marruecos , Encuestas y Cuestionarios
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