Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Resultados 1 - 20 de 994
Filtrar
Más filtros

Publication year range
1.
Biopolymers ; 115(3): e23574, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38469937

RESUMEN

Nucleophilic moieties in polysaccharides (PS) with distinct higher reactivity compared with the hydroxy group are interesting for sustainable applications in chemistry, medicine, and pharmacy. An efficient heterogeneous method for the formation of such nucleophilic PS is described. Employing alcohols as slurry medium, protonated carboxymethyl (CM) PS and hydrazine hydrate are allowed to react at elevated temperatures. The CM derivatives of starch and pullulan can be transformed almost quantitatively to the corresponding hydrazides. The reaction is less efficient for CM dextrans and CM xylans. As slurry media, 2-propanol and ethanol were probed, and the results are compared with a homogeneous procedure performed in water. Overall, the heterogeneous procedure is superior compared with the homogeneous route. 2-Propanol is the best slurry medium investigated yielding PS hydrazides with the highest nitrogen content.


Asunto(s)
Hidrazinas , Polisacáridos , Hidrazinas/química , Polisacáridos/química , Polisacáridos/síntesis química , Glucanos/química , Glucanos/síntesis química , Almidón/química , Almidón/análogos & derivados , Almidón/síntesis química , 2-Propanol/química , Dextranos/química , Dextranos/síntesis química , Etanol/química , Xilanos/química
2.
Molecules ; 29(14)2024 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-39064871

RESUMEN

The food industry extensively uses chemically modified starches and their hydrolysates, which is mainly due to their emulsification ability. Therefore, it becomes inevitable to develop new starch derivatives, including modified starch hydrolysates, and effective preparation methods to meet the increasing demands of producers, consumers, and technology. This study comprehensively researches the physical, chemical, and functional properties (such as the water-binding capacity, swelling power, solubility, and fat absorption capacity) of chemically modified biopolymers and their enzymatic hydrolysis products. We utilized oxidized and acetylated potato and waxy-corn starches with varying degrees of substitution by carboxyl and acetyl groups in our research. The process of enzymatic hydrolysis was performed in a recirculated membrane reactor (CRMR). Our findings indicated that the physicochemical properties of starch derivatives and their hydrolysates depended on the biological origin of the biopolymer and the type and degree of modification. However, the presence of carboxyl groups in the modified starch molecules is critical and affects the rheological properties and water-binding capacity of the starch preparations. For example, in the case of waxy-corn starch preparations with a lower content of carboxyl groups (i.e., derivatives with a low degree of oxidation), the water-binding capacity (WBC) increases when compared to native starch. The highest WBC value of 206.3% was noted for the doubly modified waxy-corn starch with an oxidation degree of 0.2% and an acetylation degree of 2.5%, while native waxy-corn starch shows a WBC of 161.4%. In contrast, it was observed that preparations with a higher content of carboxyl groups, i.e., derivatives with an oxidation degree of 2.5%, show a lower swelling power compared to native waxy starch.


Asunto(s)
Almidón , Almidón/química , Almidón/análogos & derivados , Hidrólisis , Tecnología de Alimentos/métodos , Solubilidad , Agua/química , Oxidación-Reducción , Solanum tuberosum/química , Acetilación , Reología
3.
Molecules ; 29(10)2024 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-38792242

RESUMEN

The development of immobilized enzymes with high activity and stability is critical. Metal-organic frameworks (MOFs) have attracted much academic and industrial interest in the field of enzyme immobilization due to their unique properties. In this study, the amino-functionalized ionic liquid (NIL)-modified metal-organic framework (UiO-66-NH2) was prepared to immobilize Candida rugosa lipase (CRL), using dialdehyde starch (DAS) as the cross-linker. The results of the Fourier transform infrared (FT-IR) spectra, X-ray powder diffraction (XRD), and scanning electronic microscopy (SEM) confirmed that the NIL was successfully grafted to UiO-66-NH2. The CRL immobilized on NIL-modified UiO-66-NH2 (UiO-66-NH2-NIL-DAS@CRL) exhibited satisfactory activity recovery (79.33%), stability, reusability, and excellent organic solvent tolerance. The research results indicated that ionic liquid-modified UiO-66-NH2 had practical potential for application in enzyme immobilization.


Asunto(s)
Enzimas Inmovilizadas , Líquidos Iónicos , Lipasa , Estructuras Metalorgánicas , Lipasa/química , Lipasa/metabolismo , Líquidos Iónicos/química , Enzimas Inmovilizadas/química , Estructuras Metalorgánicas/química , Estabilidad de Enzimas , Espectroscopía Infrarroja por Transformada de Fourier , Difracción de Rayos X , Almidón/química , Almidón/análogos & derivados , Saccharomycetales/enzimología , Ácidos Ftálicos
4.
J Sci Food Agric ; 104(6): 3585-3593, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38150581

RESUMEN

BACKGROUND: Modified polysaccharides have greatly expanded applications in comparison with native polysaccharides due to their improved compatibility and interactions with proteins and active compounds in food-related areas. Nonetheless, there is a noticeable dearth of research concerning the utilization of carboxymethyl starch (CMS) as a microcapsule wall material in food processing, despite its common use in pharmaceutical delivery. The development of an economical and safe embedding carrier using CMS and gelatin (GE) holds immense importance within the food-processing industry. In this work, the potential of innovative coacervates formed by the combination of GE and CMS as a reliable, stable, and biodegradable embedding carrier is evaluated by turbidity measurements, thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and rheological measurements. RESULTS: The results indicate that GE-CMS coacervates primarily resulted from electrostatic interactions and hydrogen bonding. The optimal coacervation was observed at pH 4.6 and with a GE/CMS blend ratio of 3:1 (w/w). However, the addition of NaCl reduced coacervation and made it less sensitive to temperature changes (35-55 °C). In comparison with individual GE or CMS, the coacervates exhibited higher thermal stability, as shown by TGA. X-ray diffraction analysis shows that the GE-CMS coacervates maintained an amorphous structure. Rheological testing reveals that the GE-CMS coacervates exhibited shear-thinning behavior and gel-like properties. CONCLUSION: Overall, attaining electroneutrality in the mixture boosts the formation of a denser structure and enhances rheological properties, leading to promising applications in food, biomaterials, cosmetics, and pharmaceutical products. © 2023 Society of Chemical Industry.


Asunto(s)
Gelatina , Polisacáridos , Almidón/análogos & derivados , Gelatina/química , Polisacáridos/química , Proteínas
5.
J Sci Food Agric ; 104(14): 8580-8592, 2024 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-38925572

RESUMEN

BACKGROUND: Proteins and anionic octenyl succinic anhydride (OSA)-modified starch (OSA-starch) are common ingredients in food systems. The interactions between OSA-starch and protein are found to alter the structural and functional properties of the protein-OSA-starch complexes. In this regard, the close understanding of the relationship among the molecular interactions between whey protein isolate (WPI) and OSA-high amylose corn starch (HAS), structure changes and rheological, digestibility and release properties of WPI-OSA-HAS was investigated. RESULTS: The molecular interactions of WPI-OSA-HAS were significant for increasing the surface rough, solubility, storage modulus and loss modulus, but decreasing the R1047/1022 values. For the nutritional evaluation, the anti-digestibility of WPI-OSA-HAS was enhanced with increased resistant starch + slowly digestible starch contents and decreased equilibrium hydrolysis percentage and kinetic constant. During the digestion, part of the starch granule, OSA groups and WPI were lost, but the loss was lower than for OSA-HAS. Furthermore, the results of curcumin-loaded WPI-OSA-HAS in simulated gastrointestinal fluids demonstrated that curcumin could be gradually released to simulate colonic fluid. Notably, the interaction between WPI and OSA-HAS depended on the WPI concentration with the stronger molecular interactions obtained at 35% concentration. CONCLUSION: These results provided important information concerning how to adjust the rheological, anti-digestibility and release properties of WPI-OSA-HAS through altering the electrostatic interactions and hydrophobic interactions of WPI-OSA-HAS. © 2024 Society of Chemical Industry.


Asunto(s)
Digestión , Reología , Solubilidad , Almidón , Anhídridos Succínicos , Proteína de Suero de Leche , Almidón/química , Almidón/análogos & derivados , Almidón/metabolismo , Anhídridos Succínicos/química , Proteína de Suero de Leche/química , Humanos , Hidrólisis , Amilosa/química
6.
Pak J Pharm Sci ; 37(1): 115-121, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38741407

RESUMEN

Migraine is one of the common neurological disease affecting around 23% of the Pakistani population. Prompt treatment is required to regain the functional ability of patients. The present study was designed to develop sumatriptan succinate orodispersible tablets that would quickly overcome acute migraine episodes using 22 full-factorial design. The chitosan and sodium starch glycolate were taken as independent variables; friability, disintegration, dispersion time and water absorption ratio as response variables. Eight trial formulations were generated by Design Expert® software. The main effect plots were used to check the interaction of formulations with response variables. All trial formulations showed good micromeritic properties in terms of angle of repose (19.59o-24.57°), Carr's index (17.08-24.90%) and Hausner's ratio (1.20-1.33). The tablets wetted quickly (17.1- 39 sec) in dispersion medium, showed higher water absorption ratio (188-341 sec) and disintegrated quickly (13-20 sec) with an excellent dissolution rate (94-99%). The main effect plots show interactions between the independent variables against most of the study responses. A 22 full-factorial model was found to be effective in studying the influence of formulation variables on response parameters. Both chitosan and sodium starch glycolate can be used in combination to fabricate an effective orodispersible formulation of sumatriptan succinate.


Asunto(s)
Quitosano , Trastornos Migrañosos , Almidón , Sumatriptán , Comprimidos , Sumatriptán/administración & dosificación , Sumatriptán/química , Trastornos Migrañosos/tratamiento farmacológico , Almidón/química , Almidón/análogos & derivados , Almidón/administración & dosificación , Quitosano/química , Humanos , Administración Oral , Solubilidad , Composición de Medicamentos , Química Farmacéutica , Excipientes/química
7.
Int J Mol Sci ; 23(10)2022 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-35628197

RESUMEN

Due to the growing demand for sustainable hygiene products (that will exhibit biodegradability and compostability properties), the challenge of developing a superabsorbent polymer that absorbs significant amounts of liquid has been raised so that it can be used in the hygiene sector in the future. The work covers the study of the swelling and dehydration kinetics of hydrogels formed by grafting polymerization of carboxymethyl starch (CMS) and chitosan (Ch). Vanillin (Van) was used as the crosslinking agent. The swelling and dehydration kinetics of the polymers were measured in various solutes including deionized water buffers with pH from 1 to 12 and in aqueous solutions of sodium chloride at 298 and 311 K. The surface morphology and texture properties of the analyzed hydrogels were observed by scanning electron microscopy (SEM). The influence of this structure on swelling and dehydration is discussed. Fourier transform infrared (FTIR) analyses confirmed the interaction between the carboxymethyl starch carbonyl groups and the chitosan amino groups in the resulting hydrogels. Additionally, spectroscopic analyses confirmed the formation of acetal crosslink bridges including vanillin molecules. The chemical dynamics studies revealed that new hydrogel dehydration kinetics strongly depend on the vanillin content. The main significance of the study concerns the positive results of the survey for the new superabsorbent polymer material, coupling high fluid absorbance with biodegradability. The studies on biodegradability indicated that resulting materials show good environmental degradability characteristics and can be considered true biodegradable superabsorbent polymers.


Asunto(s)
Quitosano , Benzaldehídos , Quitosano/química , Deshidratación , Humanos , Hidrogeles/química , Polímeros/química , Almidón/análogos & derivados , Agua/química
8.
Int J Mol Sci ; 23(14)2022 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-35886996

RESUMEN

In recent years, new cross-linkers from renewable resources have been sought to replace toxic synthetic compounds of this type. One of the most popular synthetic cross-linking agents used for biomedical applications is glutaraldehyde. However, the unreacted cross-linker can be released from the materials and cause cytotoxic effects. In the present work, dialdehyde starch nanocrystals (NDASs) were obtained from this polysaccharide nanocrystal form as an alternative to commonly used cross-linking agents. Then, 5-15% NDASs were used for chemical cross-linking of native chitosan (CS), gelatin (Gel), and a mixture of these two biopolymers (CS-Gel) via Schiff base reaction. The obtained materials, forming thin films, were characterized by ATR-FTIR, SEM, and XRD analysis. Thermal and mechanical properties were determined by TGA analysis and tensile testing. Moreover, all cross-linked biopolymers were also characterized by hydrophilic character, swelling ability, and protein absorption. The toxicity of obtained materials was tested using the Microtox test. Dialdehyde starch nanocrystals appear as a beneficial plant-derived cross-linking agent that allows obtaining cross-linked biopolymer materials with properties desirable for biomedical applications.


Asunto(s)
Proteínas Sanguíneas , Quitosano , Reactivos de Enlaces Cruzados , Gelatina , Nanopartículas , Almidón , Materiales Biocompatibles/química , Materiales Biocompatibles/metabolismo , Proteínas Sanguíneas/química , Proteínas Sanguíneas/metabolismo , Quitosano/química , Quitosano/metabolismo , Reactivos de Enlaces Cruzados/química , Reactivos de Enlaces Cruzados/metabolismo , Gelatina/química , Gelatina/metabolismo , Humanos , Nanopartículas/química , Nanopartículas/metabolismo , Almidón/análogos & derivados , Almidón/química , Almidón/metabolismo
9.
Molecules ; 27(2)2022 Jan 06.
Artículo en Inglés | MEDLINE | ID: mdl-35056648

RESUMEN

Carboxymethyl rice starch films were prepared from carboxymethyl rice starch (CMSr) treated with sodium hydroxide (NaOH) at 10-50% w/v. The objective of this research was to determine the effect of NaOH concentrations on morphology, mechanical properties, and water barrier properties of the CMSr films. The degree of substitution (DS) and morphology of native rice starch and CMSr powders were examined. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), and differential scanning calorimetry (DSC) were used to investigate the chemical structure, crystallinity, and thermal properties of the CMSr films. As the NaOH concentrations increased, the DS of CMSr powders increased, which affected the morphology of CMSr powders; a polyhedral shape of the native rice starch was deformed. In addition, the increase in NaOH concentrations of the synthesis of CMSr resulted in an increase in water solubility, elongation at break, and water vapor permeability (WVP) of CMSr films. On the other hand, the water contact angle, melting temperature, and the tensile strength of the CMSr films decreased with increasing NaOH concentrations. However, the tensile strength of the CMSr films was relatively low. Therefore, such a property needs to be improved and the application of the developed films should be investigated in the future work.


Asunto(s)
Oryza/química , Hidróxido de Sodio/química , Almidón/análogos & derivados , Vapor , Temperatura , Resistencia a la Tracción , Permeabilidad , Solubilidad , Almidón/química , Almidón/metabolismo
10.
J Sci Food Agric ; 102(14): 6373-6386, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-35535559

RESUMEN

BACKGROUND: Catechins, a member of the flavonoids, exist widely in teas, and have health benefits. However, catechins have poor stability, which greatly limits their application. In order to improve the stability of catechins, different catechins including (-)-epicatechin (EC), (-)-epicatechin gallate (ECG), (-)-epigallocatechin (EGC) and (-)-epigallocatechin gallate (EGCG) were conjugated onto dialdehyde starch by acid-mediated coupling method. The structure, stability and antioxidant activity of dialdehyde starch-catechin conjugates were determined. RESULTS: Thin-layer chromatography and ultraviolet-visible spectroscopy, fluorescence, nuclear magnetic resonance and infrared spectra revealed that catechins were successfully conjugated onto dialdehyde starch, coupling between 6-H/8-H of catechins' A ring and dialdehyde starch's aldehyde groups. The conjugates presented an amorphous structure and sheet-like and/or blocky morphologies. As compared to dialdehyde starch, the conjugates showed enhanced thermal stability. Furthermore, the stability of catechins in pH 7.4 phosphate-buffered saline was improved after conjugating onto dialdehyde starch. The conjugates exhibited significantly higher antioxidant activities than dialdehyde starch, decreasing in the following order: dialdehyde starch-ECG, dialdehyde starch-EGCG, dialdehyde starch-EC, dialdehyde starch-EGC and dialdehyde starch. CONCLUSION: Dialdehyde starch-catechin conjugates have great potential as stable antioxidant agents. © 2022 Society of Chemical Industry.


Asunto(s)
Catequina , Aldehídos/análisis , Antioxidantes/análisis , Catequina/análogos & derivados , Catequina/química , Flavonoides/análisis , Fosfatos , Almidón/análogos & derivados , Té/química
11.
J Cell Physiol ; 236(5): 4066-4075, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33151570

RESUMEN

Controlled-release drug delivery systems are promising platforms in medicine. Among various types of material in drug delivery, hydrogels are interesting ones. They are water-soluble and tissue compatible polymers with a high capacity to carry and release drugs in a controllable manner. In this study, we introduce the synthesis, characterization, and application of an α-amylase responsive hydrogel in controlled drug delivery. The newly synthesized starch-based hydrogels structurally characterized by means of Fourier-transform infrared spectroscopy and scanning electron microscopy. A proapoptotic drug, doxorubicin, was loaded into the hydrogels and the controlled release of the drug was assessed in the presence of α-amylase and ultimately it was evaluated to controlled-drug release in vitro and subsequently in killing cancer cells. Our results highlight the effectiveness of temporal drug delivery using α-amylase responsive hydrogels in killing cancer cells.


Asunto(s)
Hidrogeles/síntesis química , Almidón/análogos & derivados , alfa-Amilasas/metabolismo , Muerte Celular , Línea Celular Tumoral , Reactivos de Enlaces Cruzados/química , Doxorrubicina/química , Doxorrubicina/farmacología , Humanos , Espectroscopía Infrarroja por Transformada de Fourier , Almidón/metabolismo
12.
Int J Mol Sci ; 22(5)2021 Mar 03.
Artículo en Inglés | MEDLINE | ID: mdl-33802469

RESUMEN

In this study, nanocomposite hydrogels composed of sodium carboxymethylated starch (CMS)-containing CuO nanoparticles (CMS@CuO) were synthesized and used as experimental wound healing materials. The hydrogels were fabricated by a solution-casting technique using citric acid as a crosslinking agent. They were characterized by Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and thermogravimetric analysis (TGA) to evaluate their physicochemical properties. In addition, swelling, antibacterial activities, antioxidant activities, cytotoxicity, and in vivo wound healing were investigated to evaluate the wound healing potential of the CMS@CuO nanocomposite hydrogels. Growth inhibition of the Gram-positive and Gram-negative pathogens, antioxidant activity, and swelling were observed in the CMS@CuO nanocomposite hydrogels containing 2 wt.% and 4 wt.% CuO nanoparticles. The hydrogel containing 2 wt.% CuO nanoparticles displayed low toxicity to human fibroblasts and exhibited good biocompatibility. Wounds created in rats and treated with the CMS@2%CuO nanocomposite hydrogel healed within 13 days, whereas wounds were still present when treated for the same time-period with CMS only. The impact of antibacterial and antioxidant activities on accelerating wound healing could be ascribed to the antibacterial and antioxidant activities of the nanocomposite hydrogel. Incorporation of CuO nanoparticles in the hydrogel improved its antibacterial properties, antioxidant activity, and degree of swelling. The present nanocomposite hydrogel has the potential to be used clinically as a novel wound healing material.


Asunto(s)
Antibacterianos/química , Antioxidantes/química , Cobre/química , Hidrogeles/química , Nanopartículas/química , Almidón/análogos & derivados , Cicatrización de Heridas/efectos de los fármacos , Animales , Antibacterianos/farmacología , Antioxidantes/farmacología , Células Cultivadas , Quitosano/química , Fibroblastos/efectos de los fármacos , Humanos , Masculino , Pruebas de Sensibilidad Microbiana , Nanocompuestos/química , Ratas , Ratas Wistar , Almidón/química , Difracción de Rayos X
13.
Prep Biochem Biotechnol ; 51(6): 599-606, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33427021

RESUMEN

A new fluorometric method was developed for the determination of α-amylase activity in human serum samples. Firstly, a saturated starch-iodine complex (SI) was prepared. The SI complex was combined with sodium fluorescein to form a starch-iodine-sodium fluorescein complex (SIF). As the SIF complex decomposes with the α-amylase enzymatic hydrolysis of starch, the intensity of its fluorescence emission increases. The α-amylase activity is determined using the increased fluorescence emission intensity following hydrolysis of the SIF complex by α-amylase. The optimum pH, optimum buffer concentration, optimum temperature, and interference effect were identified for the developed fluorometric measurement method. Under the optimum conditions, a linear calibration curve was obtained between 0.18 and 9.00 U/L for α-amylase. The α-amylase activity in the human serum sample was also determined by our prepared measurement system and compared with the result from a medical center. Both methods are in good agreement with each other. Because this newly developed fluorometric method for α-amylase activity in serum samples is inexpensive, easy to use, and carried out to detect a very low amount of human serum α-amylase with sensitivity, it can be proposed this method for alpha-amylase activity assay in all other biological samples.


Asunto(s)
Fluoresceína/química , Fluorometría , Almidón/análogos & derivados , alfa-Amilasas/sangre , Humanos , Almidón/química
14.
Molecules ; 26(8)2021 Apr 11.
Artículo en Inglés | MEDLINE | ID: mdl-33920373

RESUMEN

The study focused on the influence of starch modified by octenyl succinic anhydride (OSA) on the rheological and thermal properties of gluten-free dough containing corn and potato starch with the addition of pectin and guar gum as structure-forming substances. The starch blend used in the original dough recipe was partially (5% to 15%) replaced with OSA starch. The rheological properties of dough samples were determined, and the properties of the resulting bread were analyzed. It was found that the dough samples behaved as weak gels, and the values of storage and loss moduli (G' and G″, respectively) significantly depended on angular frequency. Various shares of OSA starch in recipes modified dough in different ways, causing changes in its rheological characteristics. The introduction of OSA starch preparations resulted in changes in the bread volume and physical characteristics of the crumb. All the applied preparations caused an increase in bread porosity and the number of pores larger than 5 mm, and there was a parallel decrease in pore density. The presence of OSA starch preparations modified bread texture depending on the amount and type of the applied preparation. The introduction of OSA starches in gluten-free bread formulation caused a significant drop in the enthalpy of retrograded amylopectin decomposition, indicating a beneficial influence of such type of additive on staling retardation in gluten-free bread.


Asunto(s)
Pan/análisis , Tecnología de Alimentos/métodos , Galactanos/química , Mananos/química , Pectinas/química , Gomas de Plantas/química , Almidón/análogos & derivados , Culinaria/métodos , Dieta Sin Gluten , Humanos , Porosidad , Reología , Almidón/química , Zea mays/química
15.
Molecules ; 26(13)2021 Jun 24.
Artículo en Inglés | MEDLINE | ID: mdl-34202905

RESUMEN

Cereals are subject to contamination by pathogenic fungi, which damage grains and threaten public health with their mycotoxins. Fusarium graminearum and its mycotoxins, trichothecenes B (TCTBs), are especially targeted in this study. Recently, the increased public and political awareness concerning environmental issues tends to limit the use of traditional fungicides against these pathogens in favor of eco-friendlier alternatives. This study focuses on the development of biofungicides based on the encapsulation of a curcumin derivative, tetrahydrocurcumin (THC), in polysaccharide matrices. Starch octenylsuccinate (OSA-starch) and chitosan have been chosen since they are generally recognized as safe. THC has been successfully trapped into particles obtained through a spray-drying or freeze-drying processes. The particles present different properties, as revealed by visual observations and scanning electron microscopy. They are also different in terms of the amount and the release of encapsulated THC. Although freeze-dried OSA-starch has better trapped THC, it seems less able to protect the phenolic compound than spray-dried particles. Chitosan particles, both spray-dried and lyophilized, have shown promising antifungal properties. The IC50 of THC-loaded spray-dried chitosan particles is as low as 0.6 ± 0.3 g/L. These particles have also significantly decreased the accumulation of TCTBs by 39%.


Asunto(s)
Antifúngicos , Agentes de Control Biológico , Quitosano , Fusarium/crecimiento & desarrollo , Almidón/análogos & derivados , Antifúngicos/química , Antifúngicos/farmacología , Agentes de Control Biológico/química , Agentes de Control Biológico/farmacología , Quitosano/química , Quitosano/farmacología , Curcumina/análogos & derivados , Curcumina/química , Curcumina/farmacología , Almidón/química , Almidón/farmacología
16.
Anal Biochem ; 597: 113696, 2020 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-32201136

RESUMEN

Amylolytic enzymes are a group of proteins degrading starch to its constitutional units. For high-throughput screening, simple yet accurate methods in addition to the reducing ends assays are required. In this article, the iodine assay, a photometric assay based on the intensely colored starch-iodine complex, was adapted to enable accurate and objective differentiation between enzyme and background activity using a newly introduced mathematical factor. The method was further improved by designing a simple setup for multiple time point detection and discussing the applicability of single wavelength measurements.


Asunto(s)
Almidón/análogos & derivados , alfa-Amilasas/análisis , Almidón/química , Almidón/metabolismo , alfa-Amilasas/metabolismo
17.
Drug Dev Ind Pharm ; 46(1): 42-49, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31794271

RESUMEN

The number of Parkinson's disease (PD) patients with the advanced phase and motor fluctuations is increasing. The objective of this study is developing levodopa/benzylhydrazine orally disintegrating tablets (L/B ODTs), which would provide greater convenience and ease of use than conventional tablets for these patients. In the present study, the L/B ODTs were developed successfully with an optimized formulation using response surface methodology (RSM). The direct compression technology was employed for the preparation of L/B ODTs. Considerably shorter disintegration time and faster dissolution profile were obtained under the optimum formulation with microcrystalline cellulose 25.7%, cross-polyvinylpyrrolidone 6.22% and Sodium carboxymethyl starch 5.36%. The content uniformity (%) of levodopa and benzylhydrazine was 50 ± 1.4% and 14.25 ± 0.6%, respectively. Thickness, friability, hardness and wetting time were 2.8 ± 0.05 mm, 0.46 ± 0.21%, 5.42 ± 1.1 kp and 31.2 ± 2.1 s, respectively, and all of data well comply with the General Principles of the Chinese Pharmacopeia. Mannitol of 22% in formulation could bring a pleasant taste: sweet, cool and refreshing. Almost all the volunteers felt that the ODTs had good taste, no roughness, and no gritty feeling, indicating that the ODTs prepared had good palatability, so patients will have good compliance when taking medicine.


Asunto(s)
Antiparkinsonianos/administración & dosificación , Excipientes/química , Hidrazinas/administración & dosificación , Levodopa/administración & dosificación , Administración Oral , Adulto , Antiparkinsonianos/química , Celulosa/química , Química Farmacéutica , Combinación de Medicamentos , Liberación de Fármacos , Femenino , Humanos , Hidrazinas/química , Levodopa/química , Masculino , Povidona/química , Almidón/análogos & derivados , Almidón/química , Comprimidos , Gusto , Tecnología Farmacéutica , Adulto Joven
18.
Molecules ; 25(14)2020 Jul 16.
Artículo en Inglés | MEDLINE | ID: mdl-32708560

RESUMEN

In order to improve the mechanical properties and water resistance of thermoplastic starch (TPS), a novel reinforcement of dialdehyde lignocellulose (DLC) was prepared via the oxidation of lignocellulose (LC) using sodium periodate. Then, the DLC-reinforced TPS composites were prepared by an extrusion and injection process using glycerol as a plasticizer. The DLC and LC were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM), and the effects of DLC content on the properties of the DLC/TPS composites were investigated via the evaluation of SEM images, mechanical properties, thermal stability, and contact angles. XRD showed that the crystallinity of the DLC decreased due to oxidation damage to the LC. SEM showed good dispersion of the DLC in the continuous TPS phase at low amounts of DLC, which related to good mechanical properties. The tensile strength of the DLC/TPS composite reached a maximum at a DLC content of 3 wt.%, while the elongation at break of the DLC/TPS composites increased with increasing DLC content. The DLC/TPS composites had better thermal stability than the neat TPS. As the DLC content increased, the water resistance first increased, then decreased. The highest tensile strength and elongation at break reached 5.26 MPa and 111.25%, respectively, and the highest contact angle was about 90.7°.


Asunto(s)
Lignina/química , Nanocompuestos/química , Almidón/análogos & derivados , Glicerol/química , Lignina/síntesis química , Ácido Peryódico/química , Plastificantes/química , Poliésteres/química , Almidón/síntesis química , Almidón/química , Temperatura , Resistencia a la Tracción , Difracción de Rayos X
19.
J Sci Food Agric ; 100(6): 2807-2811, 2020 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31975414

RESUMEN

BACKGROUND: Pickering emulsions are known to have advantages over conventional emulsions, in particular, improved and long-term stability against coalescence. This research is an eight-year stability investigation of oil-in-water Pickering emulsions stabilized by quinoa starch granules modified by octenyl succinic anhydride (OSA). Two different concentrations of starch (i.e. 200 and 600 mg mL-1 based on oil) were used at oil fraction (ϕ) of 0.1. The emulsions were prepared using a high-pressure homogenizer. The emulsions were stored in a refrigerator (at 6 °C) and evaluated using particle size analyzer over the storage period and light microscopy at the end of the storage period. RESULTS: Starch granule stabilized Pickering emulsions produced by a high-pressure homogenizer displayed remarkable storage stability over the eight years with no indication of coalescence. In addition, the results showed that increasing the concentration of starch granules resulted in a decrease in droplet sizes. The sizes measured by the particle size analyzer showed a decline over the storage period which was due to dissociation of some networks of aggregated droplets that, in addition to representing smaller droplet sizes, resulted in the release of free and unbound starch entrapped in these networks. CONCLUSIONS: This study showed that Pickering emulsions produced by OSA modified starch granules from quinoa can be used in practical applications for the development of highly stable formulations when prolonged storage is required. © 2020 Society of Chemical Industry.


Asunto(s)
Emulsionantes/química , Emulsiones , Almidón/análogos & derivados , Chenopodium quinoa , Estudios Longitudinales , Tamaño de la Partícula , Almidón/química , Triglicéridos/química , Agua/química
20.
Biomacromolecules ; 20(10): 3819-3830, 2019 10 14.
Artículo en Inglés | MEDLINE | ID: mdl-31490664

RESUMEN

Naturally, cells reside in three-dimensional (3D) microenvironments composed of biopolymers that guide cellular behavior via topographical features as well as through mechanical and biochemical cues. However, most studies describing the influence of topography on cells' behavior are performed on rigid and synthetic two-dimensional substrates. To design systems that more closely resemble native microenvironments, herein we develop 3D nanocomposite hydrogels consisting of starch nanocrystals (SNCs) embedded in a gelatin matrix. The incorporation of different concentrations of SNCs (0.05, 0.2, and 0.5 wt %) results in an increase of compressive modulus when compared to hydrogels without SNCs, without affecting the swelling ratio, thus providing a tunable system. Confirming the cytocompatibility of the novel composites, the viability of encapsulated L929 fibroblasts is >90% in all hydrogels. The cellular metabolic activity and DNA content are similar for all formulations and increase over time, indicating that the fibroblasts proliferate within the hydrogels. After 4 d of culture, Live/Dead staining and F-actin/nuclei staining show that the encapsulated fibroblasts develop an elongated morphology in the hydrogels. On the other hand, encapsulated chondrogenic progenitor ATDC5 cells also maintain a viability around 90% but display a round morphology, especially in the hydrogels with SNCs, indicating a potential application of the materials for cartilage tissue engineering. We believe that topographical and mechanical cues within 3D microenvironments can be a powerful tool to instruct cells' behavior and that the developed gelatin/SNC nanocomposite warrants further study.


Asunto(s)
Hidrogeles/química , Nanocompuestos/química , Almidón/análogos & derivados , Andamios del Tejido/química , Animales , Línea Celular , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Forma de la Célula/efectos de los fármacos , Fuerza Compresiva , Hidrogeles/farmacología , Ratones , Humectabilidad
SELECCIÓN DE REFERENCIAS
Detalles de la búsqueda