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1.
Int J Mol Sci ; 24(3)2023 Jan 18.
Artículo en Inglés | MEDLINE | ID: mdl-36768226

RESUMEN

The quest for sustainable biomaterials with excellent biocompatibility and tailorable properties has put polyhydroxyalkanoates (PHAs) into the research spotlight. However, high production costs and the lack of bioactivity limit their market penetration. To address this, poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) was combined with a bacterial pigment with strong anticancer activity, prodigiosin (PG), to obtain functionally enhanced PHBV-based biomaterials. The samples were produced in the form of films 115.6-118.8 µm in thickness using the solvent casting method. The effects of PG incorporation on the physical properties (morphology, biopolymer crystallinity and thermal stability) and functionality of the obtained biomaterials were investigated. PG has acted as a nucleating agent, in turn affecting the degree of crystallinity, thermal stability and morphology of the films. All samples with PG had a more organized internal structure and higher melting and degradation temperatures. The calculated degree of crystallinity of the PHBV copolymer was 53%, while the PG1, PG3 and PG3 films had values of 64.0%, 63.9% and 69.2%, respectively. Cytotoxicity studies have shown the excellent anticancer activity of films against HCT116 (colon cancer) cells, thus advancing PHBV biomedical application potential.


Asunto(s)
Poliésteres , Polihidroxialcanoatos , Poliésteres/química , Prodigiosina/farmacología , Materiales Biocompatibles/farmacología , Materiales Biocompatibles/química
2.
Eur J Neurol ; 28(8): 2639-2647, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33988886

RESUMEN

BACKGROUND AND PURPOSE: Improving understanding of study contents and procedures might enhance recruitment into studies and retention during follow-up. However, data in stroke patients on understanding of the informed consent (IC) procedure are sparse. METHODS: We conducted a cross-sectional study among ischemic stroke patients taking part in the IC procedure of an ongoing cluster-randomized secondary prevention trial. All aspects of the IC procedure were assessed in an interview using a standardized 20-item questionnaire. Responses were collected within 72 h after the IC procedure and analyzed quantitatively and qualitatively. Participants were also asked their main reasons for participation. RESULTS: A total of 146 stroke patients (65 ± 12 years old, 38% female) were enrolled. On average, patients recalled 66.4% (95% confidence interval = 65.2%-67.5%) of the content of the IC procedure. Most patients understood that participation was voluntary (99.3%) and that they had the right to withdraw consent (97.1%); 79.1% of the patients recalled the study duration and 56.1% the goal. Only 40.3% could clearly state a benefit of participation, and 28.8% knew their group allocation. Younger age, higher graduation, and allocation to the intervention group were associated with better understanding. Of all patients, 53% exclusively stated a personal and 22% an altruistic reason for participation. CONCLUSIONS: Whereas understanding of patient rights was high, many patients were unable to recall other important aspects of study content and procedures. Increased attention to older and less educated patients may help to enhance understanding in this patient population. Actual recruitment and retention benefit of an improved IC procedure remains to be tested in a randomized trial.


Asunto(s)
Comprensión , Accidente Cerebrovascular , Anciano , Estudios Transversales , Femenino , Humanos , Consentimiento Informado , Masculino , Persona de Mediana Edad , Prevención Secundaria , Accidente Cerebrovascular/prevención & control , Encuestas y Cuestionarios
3.
Molecules ; 26(13)2021 Jun 28.
Artículo en Inglés | MEDLINE | ID: mdl-34203164

RESUMEN

Freeze drying was compared with spray drying regarding feasibility to process wild thyme drugs in order to obtain dry formulations at laboratory scale starting from liquid extracts produced by different extraction methods: maceration and heat-, ultrasound-, and microwave-assisted extractions. Higher total powder yield (based on the dry weight prior to extraction) was achieved by freeze than spray drying and lower loss of total polyphenol content (TPC) and total flavonoid content (TFC) due to the drying process. Gelatin as a coating agent (5% w/w) provided better TPC recovery by 70% in case of lyophilization and higher total powder yield in case of spray drying by diminishing material deposition on the wall of the drying chamber. The resulting gelatin-free and gelatin-containing powders carried polyphenols in amount ~190 and 53-75 mg gallic acid equivalents GAE/g of powder, respectively. Microwave-assisted extract formulation was distinguished from the others by a higher content of polyphenols, proteins and sugars, higher bulk density and lower solubility. The type of the drying process mainly affected the position of the gelatin-derived -OH and amide bands in FTIR spectra. Spray-dried formulations compared to freeze-dried expressed higher thermal stability as confirmed by differential scanning calorimetry analysis and a higher diffusion coefficient; the last feature can be associated with the lower specific surface area of irregularly shaped freeze-dried particles (151-223 µm) compared to small microspheres (~8 µm) in spray-dried powder.


Asunto(s)
Gelatina/química , Extractos Vegetales/química , Thymus (Planta)/química , Liofilización , Secado por Pulverización
4.
J Microencapsul ; 36(2): 109-119, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30982381

RESUMEN

Aim: The aim was to choose the optimal encapsulation system and to incorporate encapsulates loaded with essential oil into the ice cream as a model food product. Methods: Ca-alginate beads were produced by electrostatic extrusion process. Gelatine/alginate coacervates were processed with coacervation. Carnauba wax microparticles were produced using melt dispersion process. Morphological properties, chemical, and thermal stabilities of encapsulates were tested by SEM, FTIR spectral, and thermogravimetric analysis. Results: Alginate provided sufficient emulsion stability over 1 h. Ca-alginate showed higher encapsulation efficiency (EE) (98.4 ± 4.3%) compared to carnauba wax (94.2 ± 7.8%) and gelatine/alginate coacervates (13.2 ± 1.2%). The presence of essential oil in all three types of encapsulates confirmed with FTIR. The encapsulation process ensured controlled release and thermal stability of the oil. Conclusions: Ca-alginate matrix as the most suitable for peppermint essential oil encapsulation. The sensory analysis showed that ice cream incorporating encapsulates is a promising system for the consumption of health beneficial peppermint essential oil.


Asunto(s)
Aditivos Alimentarios/química , Mentha piperita/química , Aceites Volátiles/química , Aceites de Plantas/química , Alginatos/química , Composición de Medicamentos , Emulsiones/química , Aditivos Alimentarios/administración & dosificación , Helados/análisis , Aceites Volátiles/administración & dosificación , Aceites de Plantas/administración & dosificación , Ceras/química
5.
Exp Mol Pathol ; 104(3): 199-211, 2018 06.
Artículo en Inglés | MEDLINE | ID: mdl-29727604

RESUMEN

In our recent studies we have designed fullerenol/doxorubicin nanocomposite (FNP/DOX) as the new drug nanocarrier. This research has demonstrated that this novel nanocomposite has had better implications on the liver tissue in vivo (Wistar rats treated intraperitoneally), than treatment based only on DOX. FNP/DOX has been characterised by DLS, TEM and AFM measurements which have shown that DOX loaded onto FNP did not influence fullerenol nanoparticle's size. FNP/DOX affected oxidative status in blood causing a significant decrease of catalase and SOD activity in comparison to DOX, implicating the reduction in oxidative stress. qRT-PCR results on the mRNA level of antioxidative enzymes (catalase and MnSOD) revealed that the effect of oxidative stress is significantly reduced by the treatment with FNP/DOX (p < .05). The ultrastructural analysis of the liver tissue has revealed that FNP/DOX nanocomposite generated considerably less damage in the liver tissue, than DOX applied at the same dose. Hence, our results have indicated that FNP, within FNP/DOX nanocomposite, exhibits protective effects to the liver tissue of the healthy rats.


Asunto(s)
Antibióticos Antineoplásicos/farmacología , Doxorrubicina/farmacología , Fulerenos/química , Hígado/efectos de los fármacos , Nanocompuestos/administración & dosificación , Sustancias Protectoras/farmacología , Animales , Antibióticos Antineoplásicos/administración & dosificación , Antibióticos Antineoplásicos/química , Antioxidantes/farmacología , Catalasa/metabolismo , Doxorrubicina/administración & dosificación , Doxorrubicina/química , Hígado/metabolismo , Hígado/patología , Masculino , Nanocompuestos/química , Estrés Oxidativo/efectos de los fármacos , Sustancias Protectoras/administración & dosificación , Sustancias Protectoras/química , Ratas , Ratas Wistar , Superóxido Dismutasa/metabolismo
6.
J Microencapsul ; 34(5): 475-487, 2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28715926

RESUMEN

Black soybean coat is insufficiently valorised food production waste rich in anthocyanins. The goal of the study was to examine physicochemical properties of spray dried extract of black soybean coat in regard to carrier materials: maltodextrin, gum Arabic, and skimmed milk powder. Maltodextrin and gum Arabic-based microparticles were spherical and non-porous while skimmed milk powder-based were irregularly shaped. Low water activity of microparticles (0.31-0.33), good powders characteristics, high solubility (80.3-94.3%) and encapsulation yields (63.7-77.0%) were determined. All microparticles exhibited significant antioxidant capacity (243-386 µmolTE/g), good colour stability after three months of storage and antimicrobial activity. High content of total anthocyanins, with cyanidin-3-glucoside as predominant, were achieved. In vitro release of anthocyanins from microparticles was sustained, particularly from gum Arabic-based. These findings suggest that proposed simple eco-friendly extraction and microencapsulation procedures could serve as valuable tools for valorisation and conversion of black soybean coat into highly functional and stable food colourant.


Asunto(s)
Composición de Medicamentos , Glycine max/química , Goma Arábiga/química , Leche/química , Polisacáridos/química , Animales , Antocianinas/química , Antioxidantes/química , Semillas/química
7.
J Food Sci Technol ; 54(11): 3411-3420, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29051636

RESUMEN

The goal of this study was to investigate the characteristics of grape skin extract (GSE) spray dried with different carriers: maltodextrin (MD), gum Arabic (GA) and skim milk powder (SMP). The grape skin extract was obtained from winery by-product of red grape variety Prokupac (Vitis vinifera L.). The morphology of the powders, their thermal, chemical and physical properties (water activity, bulk and tapped densities, solubility), as well as release studies in different pH conditions were analyzed. Total anthocyanin content and total phenolic content were determined by spectrophotometric methods. MD and GA-based microparticles were non-porous and spherical, while SMP-based ones were irregularly shaped. The process of spray drying Prokupac GSE using these three carriers produced powders with low water activity (0.24-0.28), good powder characteristics, high yields, and solubility higher than 90%. The obtained dissolution/release profiles indicated prolonged release of anthocyanins and phenolic compounds in different mediums, especially from GSE/GA microparticles. These results have shown that grape skin as the main by-product of wine production could be used as a source of natural colorants and bioactive compounds, and microencapsulation as a promising technique for the protection of these compounds, their stabilization in longer periods and prolonged release.

8.
Polymers (Basel) ; 16(4)2024 Feb 07.
Artículo en Inglés | MEDLINE | ID: mdl-38399848

RESUMEN

Bacterial cellulose (BC) is a highly pure polysaccharide biopolymer that can be produced by various bacterial genera. Even though BC lacks functional properties, its porosity, three-dimensional network, and high specific surface area make it a suitable carrier for functional composite materials. In the present study, BC-producing bacteria were isolated from kombucha beverage and identified using a molecular method. Two sets of the BC hydrogels were produced in static conditions after four and seven days. Afterwards, two different synthesis pathways were applied for BC functionalization. The first method implied the incorporation of previously synthesized HAp/TiO2 nanocomposite using an immersion technique, while the second method included the functionalization of BC during the synthesis of HAp/TiO2 nanocomposite in the reaction mixture. The primary goal was to find the best method to obtain the functionalized material. Physicochemical and microstructural properties were analyzed by SEM, EDS, FTIR, and XRD methods. Further properties were examined by tensile test and thermogravimetric analysis, and antimicrobial activity was assessed by a total plate count assay. The results showed that HAp/TiO2 was successfully incorporated into the produced BC hydrogels using both methods. The applied methods of incorporation influenced the differences in morphology, phase distribution, mechanical and thermal properties, and antimicrobial activity against Staphylococcus aureus (ATCC 25923), Escherichia coli (ATCC 25922), Proteus mirabilis (ATCC 12453), and Candida albicans (ATCC 10231). Composite material can be recommended for further development and application in environments that are suitable for diseases spreading.

9.
Polymers (Basel) ; 16(8)2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38674953

RESUMEN

This study presents an analysis of films which consist of two layers; one layer is PVDF as the matrix, along with fillers BaTiO3 (BT), and the second is one bacterial nanocellulose (BNC) filled with Fe3O4. The mass fraction of BT in PVDF was 5%, and the samples were differentiated based on the duration of the mechanical activation of BT. This innovative PVDF laminate polymer with environmentally friendly fillers aligns with the concept of circular usage, resulting in a reduction in plastic content and potential improvement of the piezoelectric properties of the entire composite. This work presents new, multifunctional "green" packaging materials that potentially could be a good alternative to specific popular materials used for this purpose. The synthesis of the films was carried out using the hot press method. Tensile tests, water vapor permeability examination, and structural analyses using SEM-EDS and FTIR have been conducted. The sample PVDF/BT20/BNC/Fe3O4 exhibited the best barrier properties (impermeability to water vapor), while the highest tensile strength and toughness were exhibited by the PVDF/BT5/BNC/Fe3O4 sample.

10.
Nanomaterials (Basel) ; 14(5)2024 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-38470808

RESUMEN

In order to maximally reduce the toxicity of fullerenol (the first derivative of C60, FD-C60), and increase its biomedical efficiency, the second derivative SD-C60 (3HFWC, Hyper-Harmonized Hydroxylated Fullerene Water Complex) was created. Several different methods were applied in the comparative characterization of FD-C60 and SD-C60 with the same OH groups in their core. FD-C60 as an individual structure was about 1.3 nm in size, while SD-C60 as an individual structure was 10-30 nm in size. Based on ten physicochemical methods and techniques, FD-C60 and SD-C60 were found to be two different substances in terms of size, structure, and physicochemical properties; FD-C60, at 100 °C, had endothermic characteristics, while SD-C60, at 133 °C, had exothermic characteristics; FD-C60 did not have water layers, while SD-C60 had water layers; the zeta potential of FD-C60 was -25.85 mV, while it was -43.29 mV for SD-C60. SD-C60 is a promising substance for use in cosmetics and pharmaceuticals.

11.
J Funct Biomater ; 15(3)2024 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-38535265

RESUMEN

In this study, nanochitosan dots (ChiDs) were synthesized using gamma rays and encapsulated in bacterial cellulose (BC) polymer matrix for antibiofilm potential in photodynamic therapy. The composites were analyzed for structural changes using SEM, AFM, FTIR, XRD, EPR, and porosity measurements. Additionally, ChiD release was assessed. The results showed that the chemical composition remained unaltered, but ChiD agglomerates embedded in BC changed shape (1.5-2.5 µm). Bacterial cellulose fibers became deformed and interconnected, with increased surface roughness and porosity and decreased crystallinity. No singlet oxygen formation was observed, and the total amount of released ChiD was up to 16.10%. Antibiofilm activity was higher under green light, with reductions ranging from 48 to 57% under blue light and 78 to 85% under green light. Methicillin-resistant Staphylococcus aureus was the most sensitive strain. The new photoactive composite hydrogels show promising potential for combating biofilm-related infections.

12.
Mol Divers ; 17(3): 547-61, 2013 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23748368

RESUMEN

The reactions of 21-hydroxyprogesterone with Lawesson's reagent in toluene or [Formula: see text] gave four P-heterocyclic androst-4-ene derivatives (two tautomeric pairs): 4-(3-thioxoandrost-4-en-17[Formula: see text]-yl)-1,3,2-oxathiaphosphole-2- sulfide (2), 4-(3-thioxoandrost-4-en-17[Formula: see text]-ylidene)-1,3,2-oxathiaphospholane-2-sulfide (3), 4-(3-oxoandrost-4-en-17[Formula: see text]-yl)-1,3,2-oxathiaphosphole-2-sulfide (4), and 4-(3-oxoandrost-4-en-17[Formula: see text]-ylidene)-1,3,2- oxathiaphospholane-2-sulfide (5). The structures of all novel 17-substituted steroids were elucidated from their analytic and spectral data (HRMS, IR, 1D NMR and 2D NMR-HSQC, HMBC, NOESY, COSY). The detailed NMR analysis for all compounds revealed the presence of two pairs of signals in approx. 8:2 ratio indicating the existence of two diastereoisomers (a and b) with different configurations at the phosphorus atom. A parallel analysis of heteronuclear 2D [Formula: see text]-[Formula: see text] spectra (HSQC and HMBC) and homonuclear 2D spectra (NOESY and COSY) enabled complete [Formula: see text] and [Formula: see text] assignments of each isomer and provided evidence for the preferred configuration on phosphorus atom. Cytotoxic activity in vitro was tested against four tumor cell lines (human cervix carcinoma HeLa cells, chronic myelogenous leukemia K-562 and two human breast carcinoma MDA-MB-361 and MDA-MB-453 cells). Compounds 3a,b and 4a,b showed a poor activity against HeLa and MDA-MB-453 cell lines, while against MDA-MB-361 cell line, all tested compounds exerted very weak cytotoxic effect. All compounds exerted moderate activity against K562 cells. Antimicrobial activity against Gram-positive, Gram-negative bacteria and fungal cells, and toxicity to brine shrimp Artemia salina were evaluated. All tested compounds showed strong antifungal activity.


Asunto(s)
Androstenos/farmacología , Antibacterianos/farmacología , Antifúngicos/farmacología , Antineoplásicos/farmacología , Compuestos Heterocíclicos/farmacología , Androstenos/síntesis química , Antibacterianos/síntesis química , Antibacterianos/química , Antifúngicos/síntesis química , Antifúngicos/química , Antineoplásicos/síntesis química , Antineoplásicos/química , Bacterias/efectos de los fármacos , Neoplasias de la Mama/tratamiento farmacológico , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Desoxicorticosterona/química , Evaluación Preclínica de Medicamentos , Femenino , Hongos/efectos de los fármacos , Células HeLa , Compuestos Heterocíclicos/síntesis química , Compuestos Heterocíclicos/química , Humanos , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Pruebas de Sensibilidad Microbiana , Compuestos Organotiofosforados/química
13.
IEEE Trans Vis Comput Graph ; 29(4): 2036-2052, 2023 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-34965213

RESUMEN

Agent-based synthetic crowd simulation affords the cost-effective large-scale simulation and animation of interacting digital humans. Model-based approaches have successfully generated a plethora of simulators with a variety of foundations. However, prior approaches have been based on statically defined models predicated on simplifying assumptions, limited video-based datasets, or homogeneous policies. Recent works have applied reinforcement learning to learn policies for navigation. However, these approaches may learn static homogeneous rules, are typically limited in their generalization to trained scenarios, and limited in their usability in synthetic crowd domains. In this article, we present a multi-agent reinforcement learning-based approach that learns a parametric predictive collision avoidance and steering policy. We show that training over a parameter space produces a flexible model across crowd configurations. That is, our goal-conditioned approach learns a parametric policy that affords heterogeneous synthetic crowds. We propose a model-free approach without centralization of internal agent information, control signals, or agent communication. The model is extensively evaluated. The results show policy generalization across unseen scenarios, agent parameters, and out-of-distribution parameterizations. The learned model has comparable computational performance to traditional methods. Qualitatively the model produces both expected (laminar flow, shuffling, bottleneck) and unexpected (side-stepping) emergent qualitative behaviours, and quantitatively the approach is performant across measures of movement quality.

14.
J Trace Elem Med Biol ; 80: 127286, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37634345

RESUMEN

BACKGROUND: Although luteolin has been confirmed as potent anticancer agent, its potential application as therapeutic is limited by its water solubility. To overcome this shortcoming nanoparticle technology approach was applied. Owing to their proven low toxicity and the possibility to be easily functionalized gold nanoparticles (AuNP) were the nanosystem of choice used in this study. Novel luteolin capped gold nanoparticles (AuNPL) were synthesized and their anticancer effect towards human cervical adenocarcinoma HeLa cells was investigated in vitro. METHODS: AuNPL were synthesized by reducing chloroauric acid by trisodium citrate with subsequent addition of luteoline during synthesis and their physicochemical characterization was done. AuNPL cytotoxicity against HeLa, human malignant melanoma A375, and normal human keratinocytes HaCaT cells was tested by MTT cell survival assay, and their IC50 values were determined. The capability of AuNPL to induce cell cycle arrest and apoptosis in HeLa cells were demonstrated by flow cytometry. The antioxidant activity of AuNPL was assessed by DPPH· and ABTS·+ scavenging assays. Cytoprotective properties of AuNPL towards HaCaT cells were examined by measuring the physiological and H2O2 induced intracellular reactive oxygen species (ROS) levels using flow cytometry. Also, genotoxicity of AuNPL in HaCaT cells was investigated by the single cell alkaline comet assay. RESULTS: Spherical AuNPL, stable in aqueous solution up to six months at 4 °C were obtained in the synthesis. The selectivity in the cytotoxic action of AuNPL on HeLa and A375 cancer cells compared with their cytotoxicity on normal keratinocytes HaCaT was observed. AuNPL exerted their cytotoxic activity against HeLa cells through accumulation of the cells in the subG1 phase of the cell cycle, inducing the apoptotic cell death mediated by the activation of caspase-3 - 8, and - 9. AuNPL antioxidative potential was confirmed by DPPH· and ABTS·+ scavenging assays. IC50 concentration of AuNPL exerted cytoprotective effect against HaCaT cells by the significant reduction of the physiological intracellular ROS level. Additionally, AuNPL were shown as more cytoprotective towards HaCaT cells then luteolin due to the more successful elimination of H2O2 induced intracellular ROS. Moreover, nontoxic concentrations of AuNPL did not cause considerable DNA damage of HaCaT cells, indicating low genotoxicity of the nanoparticles. CONCLUSION: Synthesized AuNPL showed selective cytotoxic activity against HeLa cells, while being nontoxic and cytoprotective against HaCaT cells. The observed findings encourage further investigation of AuNPL as a promising novel anticancer agent.


Asunto(s)
Adenocarcinoma , Antineoplásicos , Nanopartículas del Metal , Humanos , Células HeLa , Luteolina/farmacología , Luteolina/química , Oro/farmacología , Oro/química , Especies Reactivas de Oxígeno/metabolismo , Peróxido de Hidrógeno/farmacología , Nanopartículas del Metal/química , Apoptosis , Antineoplásicos/farmacología , Antineoplásicos/química , Antioxidantes/farmacología
15.
Polymers (Basel) ; 15(7)2023 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-37050283

RESUMEN

In this paper, the properties of organic-inorganic hybrid polymer materials, which were synthesized from an aluminosilicate inorganic matrix with the addition of brushite and aminosilane grafted on one side and PEI covalently bonded composites on the other side, were examined. The synthesized organic-inorganic hybrid polymers were examined in terms of a structural, morphological, thermo-gravimetric, and adsorption-desorption analysis and also as potential CO2 capturers. The structural and phase properties as well as the percentage contents of the crystalline and amorphous phase were determined by the X-ray diffraction method. The higher content of the amorphous phase in the structure of hybrid polymers was proven in metakaolin and metakaolin-brushite hybrid samples with the addition of amino silane and with 1,000,000 PEI in a structure. The DRIFT method showed the main band changes with the addition of an organic phase and inorganic matrix. Microstructural studies with the EDS analysis showed a uniform distribution of organic and inorganic phases in the hybrid geopolymers. The thermo-gravimetric analysis showed that organic compounds are successfully bonded to inorganic polymer matrix, while adsorption-desorption analysis confirmed that the organic phase completely covered the surface of the inorganic matrix. The CO2 adsorption experiments showed that the amine-modified composites have the higher capture capacity, which is 0.685 mmol·g-1 for the GM10 sample and 0.581 mmol·g-1 for the BGM10 sample, with 1,000,000 PEI in the structure.

16.
Foods ; 12(13)2023 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-37444206

RESUMEN

This study investigates the effects of ultrasound, in combination with chemical pretreatments, on the quality attributes (total phenolic and carotenoid content, antioxidant activity (2,2-Diphenyl-1-picrylhydrazyl assay (DPPH)), ferric-reducing ability (FRAP), CIE L* a* b* color, non-enzymatic browning, rehydration ratio, textural and morphological properties) of red pepper subjected to drying (hot air drying or freeze drying). The fractional factorial design was used to assess the impact of factors. The global Derringer desirability function was used to determine the optimal conditions for the best quality attributes of dried pepper. The drying method influenced total phenolic content, a* (redness), and initial rehydration ratio; pretreatment time significantly affected FRAP antiradical activity, a*, chroma and non-browning index, while pH-value had a significant effect on the texture of dried pepper. Non-enzymatic browning was reduced to 72.6%, while the DPPH antioxidant capacity of freeze-dried peppers was enhanced from 4.2% to 71.9%. Ultrasonic pretreatment led to changes in the pepper morphology, while potassium metabisulfite (KMS) was a more effective additive than citric acid.

17.
Int J Biol Macromol ; 242(Pt 2): 124837, 2023 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-37178878

RESUMEN

In this study, levan from Bacillus licheniformis NS032 was modified in an aqueous medium by octenyl succinic anhydride (OSA), and the properties of the obtained derivatives were studied. The maximum efficiency in the synthesis reaction was achieved at 40 °C and a polysaccharide slurry concentration of 30 %. Increasing the reagent concentration (2-10 %) led to an increase in the degree of substitution (0.016-0.048). Structures of derivatives were confirmed by FTIR and NMR. Scanning electronic microscopy, thermogravimetry, and dynamic light scattering analyses showed that the derivatives with degrees of substitution of 0.025 and 0.036 retained levan's porous structure and thermostability and showed better colloidal stability than the native polysaccharide. The intrinsic viscosity of derivatives increased upon modification, while the surface tension of the 1 % solution was lowered to 61 mN/m. Oil-in-water emulsions prepared with sunflower oil (10 % and 20 %) by mechanical homogenization and 2 and 10 % derivatives in the continuous phase showed mean oil droplet sizes of 106-195 µm, while the distribution curves exhibited bimodal character. The studied derivatives have a good capacity to stabilize emulsions, as they have a creaming index ranging from 73 % to 94 %. The OSA-modified levans could have potential applications in new formulations of emulsion-based systems.


Asunto(s)
Almidón , Anhídridos Succínicos , Emulsiones/química , Almidón/química , Anhídridos Succínicos/química , Fructanos
18.
Polymers (Basel) ; 15(20)2023 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-37896324

RESUMEN

In the search for environmentally friendly materials with a wide range of properties, polymer composites have emerged as a promising alternative due to their multifunctional properties. This study focuses on the synthesis of composite materials consisting of four components: bacterial nanocellulose (BNC) modified with magnetic Fe3O4, and a mixture of BaTiO3 (BT) and polyvinylidene fluoride (PVDF). The BT powder was mechanically activated prior to mixing with PVDF. The influence of BT mechanical activation and BNC with magnetic particles on the PVDF matrix was investigated. The obtained composite films' structural characteristics, morphology, and dielectric properties are presented. This research provides insights into the relationship between mechanical activation of the filler and structural and dielectric properties in the PVDF/BT/BNC/Fe3O4 system, creating the way for the development of materials with a wide range of diverse properties that support the concept of green technologies.

19.
Beilstein J Nanotechnol ; 14: 165-174, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36761674

RESUMEN

Carbon quantum dots as a novel type of carbon nanomaterials have attracted the attention of many researchers because of their unique optical, antibacterial, and anticancer properties as well as their biocompatibility. In this study, for the first time, carbon quantum dots were prepared from o-phenylenediamine dissolved in toluene by a solvothermal route. Subsequently, the prepared carbon quantum dots were encapsulated into polyurethane films by a swelling-encapsulation-shrink method. Analyses of the results obtained by different characterization methods (AFM, TEM, EDS, FTIR, photoluminescence, and EPR) indicate the significant influence of the precursor on structural, chemical, and optical properties. Antibacterial and cytotoxicity tests showed that these dots did not have any antibacterial potential, because of the low extent of reactive oxygen species production, and showed low dark cytotoxicity. By investigating the cellular uptake, it was established that these dots penetrated the HeLa cells and could be used as probes for bioimaging.

20.
Food Chem ; 402: 134299, 2023 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-36152557

RESUMEN

This study aimed to characterize mixtures of goat milk proteins and Agaricus blazei Murrill (ABM) extracts (aqueous, AE and polysaccharides, PE). The mixtures showed stable particles with ζ-potential more negative than -41.1 mV. The addition of AMB extracts to goat milk did not result in a significant particle size change, whereas their addition to heated goat milk significantly increased mean particle diameter (from 194 nm to 225 nm). Fourier Transform Infrared Spectroscopy (FTIR) showed that ABM extracts provoked changes in the secondary structure of goat milk proteins and interactions between polysaccharides and milk proteins predominantly via hydrogen and/or glycoside bonds and hydrophobic interactions. The milk protein profiles revealed proteolytic activity in mixtures with AE resulting in the formation of five new polypeptides. The different microstructures of mixtures with AE and PE were found by Scanning Electron Microscopy (SEM). A schematic representation of possible milk proteins-ABM extracts interactions has been given.


Asunto(s)
Agaricus , Proteínas de la Leche , Animales , Espectroscopía Infrarroja por Transformada de Fourier , Cabras , Agaricus/química , Polisacáridos/química , Hidrógeno , Glicósidos
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