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1.
Int J Nanomedicine ; 16: 2585-2595, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33833513

RESUMEN

Background: In cancer nanomedicine, drugs are transported by nanocarriers through a biological system to produce a therapeutic effect. The efficacy of the treatment is affected by the ability of the nanocarriers to overcome biological transport barriers to reach their target. In this work, we focus on the process of nanocarrier penetration through tumour tissue after extravasation. Visualising the dynamics of nanocarriers in tissue is difficult in vivo, and in vitro assays often do not capture the spatial and physical constraints relevant to model tissue penetration. Methods: We propose a new simple, low-cost method to observe the transport dynamics of nanoparticles through a tissue-mimetic microfluidic chip. After loading a chip with triplicate conditions of gel type and loading with microparticles, microscopic analysis allows for tracking of fluorescent nanoparticles as they move through hydrogels (Matrigel and Collagen I) with and without cell-sized microparticles. A bespoke image-processing codebase written in MATLAB allows for statistical analysis of this tracking, and time-dependent dynamics can be determined. Results: To demonstrate the method, we show size-dependence of transport mechanics can be observed, with diffusion of fluorescein dye throughout the channel in 8 h, while 20 nm carboxylate FluoSphere diffusion was hindered through both Collagen I and Matrigel™. Statistical measurements of the results are generated through the software package and show the significance of both size and presence of microparticles on penetration depth. Conclusion: This provides an easy-to-understand output for the end user to measure nanoparticle tissue penetration, enabling the first steps towards future automated experimentation of transport dynamics for rational nanocarrier design.


Asunto(s)
Geles/química , Microfluídica/métodos , Nanopartículas/administración & dosificación , Nanopartículas/metabolismo , Andamios del Tejido/química , Colágeno/química , Colágeno/metabolismo , Difusión , Humanos , Nanomedicina/métodos , Nanopartículas/química
2.
Int J Pharm Compd ; 25(2): 146-155, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33798114

RESUMEN

Recently, there has been an increase in the use of compounded topical pain preparations, raising concerns that clinicians and patients may not be aware of the potential safety risks. Topical diclofenac is one of the most widely used pain medications, often used for joint ailments such as osteoarthritis and other musculoskeletal pain. Systemic exposure to diclofenac has a dose-related risk for gastrointestinal, cardiovascular, and renal adverse events, particularly in elderly patients. Topical diclofenac preparations are frequently compounded in pharmacies at the concentrations of 1% to 10% (or higher) with or without other active ingredients such as camphor. Considering the significantly higher strengths of the compounded preparations as compared to the commercially available products (1% to 3%) and the frequency of application (sometimes up to six times a day), concerns arise as to the levels of absorption with these formulations and their potential toxicity. The objective of this initial study was formulated in an attempt to shed light on safety concerns of topical diclofenac preparations. A study was designed to evaluate the in vitro release, irritability, and permeability of three different concentrations of compounded diclofenac gels (1%, 5%, and 10%) in PLO GEL MEDIFLO and VersaPro Gel bases. Using MatTek's EpiDerm system, skin irritability and the in vitro permeation of compounded diclofenac gels were evaluated. Additionally, the in vitro release profile, drug content, content uniformity, and physical properties of the compounded gels (pH, homogeneity) were assessed. In all cases, the drug content, content uniformity, physical properties, and preparation stability during the recommended beyond-use dating (90 days) were acceptable. The release profiles of all tested preparations followed the Higuchi model. The in vitro skin irritation evaluation of the tested formulations indicated no irritant preparation. The permeability assessment of the formulated gels revealed that there is a correlation between drug release and percutaneous absorption. VersaPro Gelbased preparations, which showed a lower percentage of drug release over the experiment time, showed a significantly lower average flux at steady-state and the average percentage of absorbed dose after 24 hours. The percentage absorption (%abs) from different formulations ranged from 11.18% to 19.6% depending on the gel base. The permeability coefficient, kp, (cm/hr) ranged from 0.019 to 0.037, and the average flux (µg/cm2/hr) ranged from 8.7 to 103 depending on the gel base and the diclofenac concentration. Based on our findings and previously reported data, the possibility exists that higher diclofenac concentrations in compounded topical preparations may lead to significantly higher blood concentrations as compared to commercially available products, which in turn may also lead to serious side effects. Accordingly, there is a need for clinical studies to evaluate the safety of compounded diclofenac preparations with higher diclofenac contents than United States Food and Drug Administrationapproved formulations.


Asunto(s)
Diclofenaco , Absorción Cutánea , Administración Tópica , Anciano , Antiinflamatorios no Esteroideos/efectos adversos , Diclofenaco/efectos adversos , Geles/metabolismo , Humanos , Permeabilidad , Piel/metabolismo
3.
BMC Oral Health ; 21(1): 183, 2021 04 09.
Artículo en Inglés | MEDLINE | ID: mdl-33836740

RESUMEN

BACKGROUND: This in-vitro-study aimed to evaluate the potential of different fluoride gels to prevent gastroesophageal reflux induced erosive tooth wear. METHODS: Surface baseline profiles of a total of 50 bovine enamel specimens [randomly assigned to five groups (G1-5)] were recorded. All specimens were positioned in a custom made artificial oral cavity and perfused with artificial saliva (0.5 ml/min). Reflux was simulated 11 times a day during 12 h by adding HCl (pH 3.0) for 30 s (flow rate 2 ml/min). During the remaining 12 h (overnight), specimens were stored in artificial saliva and brushed twice a day (morning and evening) with a toothbrush and toothpaste slurry (15 brushing strokes). While specimens in the control group (G1) did not receive any further treatment, specimens in G2-5 were coated with different fluoride gels [Elmex Gelée (G2); Paro Amin Fluor Gelée (G3); Paro Fluor Gelée Natriumfluorid (G4); Sensodyne ProSchmelz Fluorid Gelée (G5)] in the evening for 30 s. After 20 days, surface profiles were recorded again and enamel loss was determined by comparing them with the baseline profiles. The results were statistically analysed using one-way analysis of variance (ANOVA) followed by Tukey`s HSD post-hoc test. RESULTS: The overall highest mean wear of enamel (9.88 ± 1.73 µm) was observed in the control group (G1), where no fluoride gel was applied. It was significantly higher (p < 0.001) compared to all other groups. G2 (5.03 ± 1.43 µm), G3 (5.47 ± 0.63 µm, p = 0.918) and G4 (5.14 ± 0.82 µm, p > 0.999) showed the overall best protection from hydrochloric acid induced erosion. Enamel wear in G5 (6.64 ± 0.86 µm) was significantly higher compared to G2 (p = 0.028) and G4 (p = 0.047). CONCLUSIONS: After 20 days of daily application, all investigated fluoride gels are able to significantly reduce gastroesophageal reflux induced loss of enamel.


Asunto(s)
Reflujo Gastroesofágico , Abrasión de los Dientes , Erosión de los Dientes , Desgaste de los Dientes , Animales , Bovinos , Fluoruros , Reflujo Gastroesofágico/etiología , Reflujo Gastroesofágico/prevención & control , Geles , Humanos , Fluoruro de Sodio , Erosión de los Dientes/etiología , Erosión de los Dientes/prevención & control
4.
AAPS PharmSciTech ; 22(3): 121, 2021 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-33796955

RESUMEN

Ginoid hydrolipodystrophy (HDLG) or "cellulite" involves alteration of the cutaneous relief and occurs in 80-90% of the female population. Several topical treatments are available with the use of substances capable of stimulating lipolysis, such as caffeine. However, the effectiveness of topical therapy is related to the processes of release and permeation of the active in skin cells. In this sense, ionic liquids, such as choline geranate, are considered to facilitate topical permeation agents. In this way, the aim of this research was to develop and evaluation of the effectiveness of a cosmetic product for topical treatment of cellulite with caffeine in association with choline geranate. The choline geranate was synthesized by the reaction between geranic acid and choline hydroxide [1: 2]. The gel was prepared using 2% Carpobol 940®, 5% caffeine, and 1% choline geranate. Preliminary and accelerated stability tests were performed by checking pH, spreadability, and organoleptic characteristics. The transdermal permeation capacity of caffeine in vitro was evaluated by the Franz cell permeation assay, and the gel cytotoxicity by the MTS method. To prove the efficacy in the treatment of cellulite, a pilot type 1 clinical trial was carried out. The formulation was considered stable and the product maintained your characteristics during 180 days of storage. The product showed moderate cytotoxicity and high skin permeation capacity. In the clinical trial, it showed results superior to the caffeine gel without ionic liquid. The developed gel favored the cutaneous permeation of caffeine, showing a promising product in the treatment of cellulite.


Asunto(s)
Cafeína/administración & dosificación , Cafeína/uso terapéutico , Lipodistrofia/tratamiento farmacológico , Administración Cutánea , Adulto , Cafeína/farmacocinética , Cosméticos , Método Doble Ciego , Composición de Medicamentos , Estabilidad de Medicamentos , Femenino , Geles , Humanos , Líquidos Iónicos , Persona de Mediana Edad , Proyectos Piloto , Absorción Cutánea
5.
Water Res ; 195: 116959, 2021 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-33676179

RESUMEN

The properties of biofilm EPS are determined by the multiple interactions between its constituents and the surrounding environment. Because of the high complexity of biofilm EPS, its constituents' characterisation is still far from thorough, and identification of these interactions cannot be done yet. Therefore, we use gels of bacterial alginate-like exopolysaccharides (ALEs) as a model component for biofilm EPS in this work. These gels have been examined for their cohesive properties as a function of CaCl2 and KCl concentration. Hereto, ALE gel layers were formed on membranes by dead-end filtration of ALE solutions. Accumulation of the cations Ca2+ and K+ in the gels could be well predicted from a Donnan equilibrium model based on the fixed negative charges in the ALE. This suggests that there is no specific binding of Ca2+ to the ALE and that on the time scale of the experiments, the Ca2+ ions can distribute freely over the gel and the surrounding solution. The concentration of fixed negative charges in the ALE was estimated around 1 mmol/g VSS (volatile suspended solids, organic mass) from the Donnan equilibrium. Moreover, an accumulation of H+ was predicted. Gels with more CaCl2 in the supernatant were more compact and bore a higher osmotic pressure than those with less CaCl2, revealing the role of Ca2+ ions in the network crosslinking. It is hypothesised that this mechanism later transitions into a rearrangement of the ALE molecules, which eventually leads to a fibrous network structure with large voids.


Asunto(s)
Alginatos , Matriz Extracelular de Sustancias Poliméricas , Biopelículas , Geles , Iones
6.
J Dairy Sci ; 104(4): 3970-3979, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33663841

RESUMEN

In this work, pressure-assisted enzymatic gelation was applied to milk proteins, with the goal of enhancing the structure and stability of pressure-created milk protein gels. High-pressure processing (HPP) at 600 MPa, 3 min, and 5°C was applied to milk protein concentrate (MPC) samples of 12.5% protein concentration, both in the absence and in the presence of calf chymosin [up to 60 IMCU (international milk-clotting units)/kg of milk] or camel chymosin (up to 45 IMCU/kg of milk). Gel hardness, water-holding capacity, and degree of proteolysis were used to assess network strength and shelf stability. The processing trials and all measurements were conducted in triplicate. Statistical analyses of the data were performed by ANOVA, at a 95% confidence level. After HPP treatment, we observed significant structural changes for all samples. Pressurization of MPC, with or without chymosin addition, led to extensive protein aggregation and network formation. The strength of HPP-created milk protein gels without chymosin addition, as measured by the elastic modulus (G'), had a value of 2,242 Pa. The value of G' increased with increasing chymosin concentration, reaching as high as 4,800 Pa for samples with 45 IMCU/kg of camel chymosin. During 4 wk of refrigerated storage, the HPP and chymosin MPC gels maintained higher gel hardness and better structural stability compared with HPP only (no chymosin) MPC gels. The water-holding capacity of the gels without chymosin remained at 100% during 28 d of refrigerated storage. The HPP and chymosin MPC gels had a lower water-holding capacity (91-94%) than the HPP-only counterparts, but their water-holding capacity did not decrease during storage. Overall, these findings demonstrate that controlled, fast structural modification of high-concentration protein systems can be obtained by HPP-assisted enzymatic treatment, and the created gels have a strong, stable network. This study provides insights into the possibility of using HPP for the development of milk-protein-based products with novel structures and textures and long refrigerated shelf life, along with the built-in safety imparted by the HPP treatment.


Asunto(s)
Quimosina , Proteínas de la Leche , Animales , Geles , Concentración de Iones de Hidrógeno , Reología
7.
J Dairy Sci ; 104(4): 4074-4083, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33663855

RESUMEN

In this study, we investigated the effect of pH and calcium on the structural properties of gels created by high-pressure processing (HPP, 600 MPa, 5°C, 3 min) of milk protein concentrate (MPC, 12.5% protein). The pH level of the MPC was varied between 6.6 and 5.1 by adding glucono-δ-lactone (GDL), and the calcium content was varied from 24 to 36 mg of Ca/g of protein by adding calcium chloride. The rheological properties and microstructure of the pressure-treated MPC were assessed. The pressurization treatments and analytical testing were conducted in triplicate. Data were analyzed statistically using one-way ANOVA with Tukey's honestly significant difference post hoc tests. A pressurization time of 3 min was sufficient to induce gel formation in MPC at pH 6.6, so it was used throughout the study. Adjusting either pH or calcium affected the structure of the HPP-created milk protein gels, likely by influencing electrostatic interactions and shifting the calcium-phosphate balance. Gels were formed after pressurization of MPC at pH above 5.3, and increasing the pH from 5.3 to 6.6 resulted in stronger gels with higher values of elastic moduli (G'). At neutral pH (6.6), adding calcium to MPC further increased G'. Scanning electron microscopy showed that reducing pH or adding calcium resulted in more porous, aggregated microstructures. These findings demonstrate the potential of HPP to create a variety of structures using MPC, facilitating a new pathway from dairy protein ingredients to novel, gel-based, high-protein foods, such as puddings or on-the-go protein bars.


Asunto(s)
Calcio , Proteínas de la Leche , Animales , Caseínas , Geles , Concentración de Iones de Hidrógeno , Reología
8.
AAPS PharmSciTech ; 22(3): 104, 2021 Mar 14.
Artículo en Inglés | MEDLINE | ID: mdl-33718986

RESUMEN

Pain is a phenomenon present in the majority of the population, affecting, among others, the elderly, overweight people, and especially recently operated patients, analgesia being necessary. In the specific case of relief of postoperative pain, different kinds of anesthetics are being used, among them bupivacaine, a widely used drug which promotes long-lasting analgesic effects. However, cardiotoxicity and neurotoxicity are related to its repetitive use. To overcome these shortcomings, Novabupi® (a racemic mixture) was developed and is marketed as an injectable solution. This formulation contains an enantiomeric excess of the levogyre isomer, which has reduced toxicity effects. Seeking to rationalize its use by extending the duration of effect and reducing the number of applications, the objectives of this work were to develop and evaluate liposomes containing Novabupi (LBPV), followed by incorporation into thermogel. Liposomes were prepared using the lipid hydration method, followed by size reduction using sonication, and the developed formulations were characterized by hydrodynamic diameter, polydispersity index (PDI), surface zeta potential, and encapsulation efficiency. The selected optimal liposomal formulation was successfully incorporated into a thermogel without loss of thermoresponsive properties, being suitable for administration as a subcutaneous injection. In the ex vivo permeation studies with fresh rodent skin, the thermogel with liposomes loaded with 0.5% LBPV (T-gel formulation 3) showed higher permeation rates compared to the starting formulation, thermogel with 0.5% LBPV (T-Gel 1), which will probably translate into better therapeutic benefits for treatment of postoperative analgesia, especially with regard to the number of doses applied.


Asunto(s)
Analgesia/métodos , Levobupivacaína/administración & dosificación , Levobupivacaína/farmacocinética , Dolor/tratamiento farmacológico , Dolor/metabolismo , Animales , Bovinos , Pollos , Membrana Corioalantoides/efectos de los fármacos , Membrana Corioalantoides/metabolismo , Geles , Humanos , Liposomas , Masculino , Ratones , Células 3T3 NIH , Técnicas de Cultivo de Órganos , Ratas , Ratas Wistar , Piel/efectos de los fármacos , Piel/metabolismo , Absorción Cutánea/efectos de los fármacos , Absorción Cutánea/fisiología
9.
Phys Rev Lett ; 126(9): 098001, 2021 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-33750145

RESUMEN

The kinetics of heat-induced gelation and the microscopic dynamics of a hen egg white gel are probed using x-ray photon correlation spectroscopy along with ultrasmall-angle x-ray scattering. The kinetics of structural growth reveals a reaction-limited aggregation process with a gel fractal dimension of ≈2 and an average network mesh size of ca. 400 nm. The dynamics probed at these length scales reveals an exponential growth of the characteristic relaxation times followed by an intriguing steady state in combination with a compressed exponential correlation function and a temporal heterogeneity. The degree of heterogeneity increases with decreasing length scale. We discuss our results in the broader context of experiments and models describing attractive colloidal gels.


Asunto(s)
Clara de Huevo/química , Modelos Químicos , Geles/química , Cinética , Dispersión del Ángulo Pequeño , Rayos X
10.
AAPS PharmSciTech ; 22(3): 87, 2021 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-33665761

RESUMEN

The commitment of the existent study was to develop a mucoadhesive in situ gel systems of vitamin B12 for the management of dry eye disease. The gels were prepared using pluronic F-127 and either of chitosan, carbapol 971P, sodium alginate, or hydroxy propyl methyl cellulose. Drug-excipients compatibility was investigated by means of differential scanning calorimetry and Fourier transform infrared spectroscopy. The gels were characterized for pH, clarity, gelling capacity, viscosity, and adhesion. In vitro release of vitamin B12 from the selected gels was investigated. In vivo effectiveness of the selected gel was determined in rabbit models using Schirmer's and fluorescein tests. The compatibility studies revealed the possibility of incidence of drug/polymer interaction in some formulations. F2-containing pluronic F127 and hydroxypropyl methyl cellulose showed the most appropriate physical characterization and in vitro release profile. The prepared gels showed prolonged drug release with drug release mechanism of combined diffusion and erosion. The in vivo study revealed good effectiveness of the prepared mucoadhesive in situ gel system of vitamin B12 in the treatment of dry eye disease that was comparable to that of the marketed drops.


Asunto(s)
Síndromes de Ojo Seco/tratamiento farmacológico , Vitamina B 12/uso terapéutico , Vitaminas/uso terapéutico , Adhesivos , Animales , Composición de Medicamentos , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Excipientes , Femenino , Geles , Derivados de la Hipromelosa , Masculino , Membrana Mucosa , Poloxámero , Conejos , Viscosidad , Vitamina B 12/administración & dosificación , Vitaminas/administración & dosificación
11.
Food Chem ; 351: 129344, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33647688

RESUMEN

Protein oxidation is considered as an important factor affecting the texture quality of surimi. In this work, the myofibrillar protein (MP) from shrimp (Penaeus vannamei) was subjected to a hydroxyl radical generating system at various concentrations of H2O2, to simulate the oxidative environment during surimi processing. After the hydroxyl radical oxidation, it was found that the carbonyl content, surface hydrophobicity, and MP aggregation increased. Meanwhile, the a-helix decreased, but ß-sheet increased after oxidation. The moderate oxidation led to a dense network microstructure, increased water holding capacity (WHC) and decreased water mobility, which ultimately enhanced textural (hardness and springiness increased by 0.51- and 0.06-fold, respectively) and rheological properties of MP gel (MPG). However, excessive oxidation could reduce the mechanical properties of MPG. The microstructure, WHC and water distribution played a key role in the mechanical properties of MPG. This study can provide a theoretical basis for processing of shrimp surimi products.


Asunto(s)
Anostraca , Fenómenos Químicos , Radical Hidroxilo/química , Proteínas Musculares/química , Animales , Geles , Interacciones Hidrofóbicas e Hidrofílicas , Oxidación-Reducción , Reología , Alimentos Marinos , Agua/química
12.
Food Chem ; 351: 129316, 2021 Jul 30.
Artículo en Inglés | MEDLINE | ID: mdl-33647701

RESUMEN

This study aimed to understand how the microstructure of gelled foods impacts the diffusion of a volatile antimicrobial compound and its efficacy at different depths from the surface. Carvacrol-loaded polylactic acid film was used to inhibit the growth of Pseudomonas fluorescens in WPI-carrageenan gels during storage at 4 °C. The diffusion of antimicrobials was increased in gels having larger average pore size. The antimicrobial efficacy of the antimicrobial packaging was dependent on the diffusion of carvacrol within the gels. The final concentration of carvacrol in the top layer was more than 4 fold higher than that in the middle layer and more than 13-fold higher than that in the bottom layer, resulting in a more effective inhibition in the top layer than those in the middle and bottom layers. Our study demonstrates the importance of considering the diffusion of antimicrobials in solid/semi-solid foods in the antimicrobial packaging design.


Asunto(s)
Antiinfecciosos/química , Cimenos/química , Conservación de Alimentos/métodos , Carragenina/química , Difusión , Geles , Porosidad
13.
AAPS PharmSciTech ; 22(3): 103, 2021 Mar 12.
Artículo en Inglés | MEDLINE | ID: mdl-33712964

RESUMEN

The topical use of rosmarinic acid (RA) in skin inflammatory pathologies is restricted due to its poor water solubility, poor permeability, and chemical instability. In this study, RA-loaded transethosomes-in-Carbopol® formulations have been developed to evaluate its anti-inflammatory activity on imiquimod-induced psoriasis-like skin inflammation in mice. In vitro release profiles demonstrated sustained behavior due to the retentive action of gel and the entrapment of RA into the vesicles. However, the low viscosity of the combined formulation increased the drug release rate. Animal evaluation of anti-inflammatory activity demonstrated that transethosomes-in-gel containing dexamethasone (Dex-TE-Gel), as positive control, showed effect in all the pro-inflammatory parameters evaluated, evidencing that these drug-loaded nanocarriers have been effectively reached the site of action. In addition, transethosomes-in-gel containing RA (RA-TE-Gel) formulations produced a great reduction in the punch edema (P < 0.001) and in TNF-α and IL-6 (P < 0.05). However, non-significant differences were obtained for IL-1ß, IL17, and MPO. Despite the protecting effect of Carbopol® and transethosomes on oxidation index and antioxidant activity of RA over the 7 days of treatment, however, a degradation process of this antioxidant to caffeic acid may be the cause of these in vivo results. We have also checked that the pH existing into the intercellular space of damaged cells (pH 6.8) may be affecting. Therefore, our results suggest that RA-TE-Gel could act as an effective RA formulation for skin delivery; further studies will help to understand the loss of activity at the cellular level.


Asunto(s)
Cinamatos/administración & dosificación , Cinamatos/uso terapéutico , Depsidos/administración & dosificación , Depsidos/uso terapéutico , Psoriasis/tratamiento farmacológico , Administración Cutánea , Animales , Dexametasona/administración & dosificación , Dexametasona/uso terapéutico , Portadores de Fármacos , Composición de Medicamentos , Sistemas de Liberación de Medicamentos , Liberación de Fármacos , Femenino , Geles , Ratones , Ratones Endogámicos BALB C , Viscosidad
14.
Food Chem ; 352: 129220, 2021 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-33684717

RESUMEN

Cationic antimicrobial peptides have raised interest as attractive alternatives to classical antibiotics, and also have utility in preventing food spoilage. We set out to enrich cationic antimicrobial peptides from milk hydrolysates using gels containing various ratios of anionic pectin/alginate. All processes were carried out with food-grade materials in order to suggest food-safe methods suited for producing food ingredients or supplements. Hydrolysed caseinate peptides retained in the gel fraction, identified by mass spectrometry, were enriched for potential antimicrobial peptides, as judged by a computational predictor of antimicrobial activity. Peptides retained in a 60:40 pectin:alginate gel fraction had a strong antimicrobial effect against 8 tested bacterial strains with a minimal inhibitory concentration of 1.5-5 mg/mL, while the unfractionated hydrolysate only had a detectable effect in one of the eight strains. Among 110 predicted antimicrobial peptides in the gel fraction, four are known antimicrobial peptides, HKEMPFPK, TTMPLW, YYQQKPVA and AVPYPQR. These results highlight the potential of pectin/alginate food-gels based processes as safe, fast, cost-effective methods to separate and enrich for antimicrobial peptides from complex food protein hydrolysates.


Asunto(s)
Alginatos/química , Péptidos Catiónicos Antimicrobianos/química , Péptidos Catiónicos Antimicrobianos/farmacología , Leche/química , Pectinas/química , Hidrolisados de Proteína/química , Secuencia de Aminoácidos , Animales , Geles , Pruebas de Sensibilidad Microbiana
15.
Carbohydr Polym ; 260: 117776, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712132

RESUMEN

Pearl millet (Pennisetum glaucum (L.) R.Br.) is a sustainable and underutilized starch source, constituting up to 70 % starch in its grain. Pearl millet could be used as a cheaper source of starch as compared to other cereals for developing functional foods. This review is mainly focused on isolation methods, and chemical composition of the pearl millet starch (PMS). Techno-functional characteristics such as; gelatinization, pasting properties, solubility, swelling power, and digestibility to infer wider application of the PMS critically highlighted in the review. Native starches have limited functionalitiesfor food applications due to the instability in developed pastes and gels. A number of modifications (physical, mechanical and enzymatic) have been developed to increase the functionality and to obtain desired characteristics of PMS thus improving its utilization in food applications. Further, the utilization of native as well as modified PMS is also discussed comprehensively. In addition, a number of recommendations to further improve its functionality and increase its application are also discussed.


Asunto(s)
Pennisetum/metabolismo , Almidón/química , Portadores de Fármacos/química , Embalaje de Alimentos , Geles/química , Peso Molecular , Nanopartículas/química , Solubilidad , Difracción de Rayos X
16.
Carbohydr Polym ; 260: 117790, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712138

RESUMEN

A novel approach was introduced to prepare very low density, highly porous, economic, reusable, hydrophobic, and magnetic cellulose aerogels from hardwood dissolving pulp via a simple freeze-drying procedure. The aerogels showed outstanding adsorption efficiency for several oils and organic solvents and demonstrated excellent selectivity for absorbing oil from an oil/water mixture. Moreover, they were easily collected by an external magnet, indicating excellent recyclability and reusable for at least 10 cycles while still retaining supreme adsorption capacity (up to 181 g/g for silicone oil). This study proposes an economic and novel method for the large-scale preparation of hydrophobic and magnetic cellulose aerogels, making them a promising candidate for the efficient and sustainable cleaning of oils and chemical spills.


Asunto(s)
Celulosa/química , Geles/química , Magnetismo , Adsorción , Interacciones Hidrofóbicas e Hidrofílicas , Aceites/química , Porosidad , Reciclaje , Propiedades de Superficie , Contaminantes Químicos del Agua/química
17.
Molecules ; 26(4)2021 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-33672689

RESUMEN

To expand the applications of graphene-based materials to biogas purification, a series of reduced graphene oxide aerogels (rGOAs) were prepared from industrial grade graphene oxide using a simple hydrothermal method. The influences of the hydrothermal preparation temperature on the textural properties, hydrophobicity and physisorption behavior of the rGOAs were investigated using a range of physical and spectroscopic techniques. The results showed that the rGOAs had a macro-porous three-dimensional network structure. Raising the hydrothermal treatment temperature reduced the number of oxygen-containing groups, whereas the specific surface area (SBET), micropore volume (Vmicro) and water contact angle values of the rGOAs all increased. The dynamic adsorption properties of the rGOAs towards hexamethyldisiloxane (L2) increased with increasing hydrothermal treatment temperature and the breakthrough adsorption capacity showed a significant linear association with SBET, Vmicro and contact angle. There was a significant negative association between the breakthrough time and inlet concentration of L2, and the relationship could be reliably predicted with a simple empirical formula. L2 adsorption also increased with decreasing bed temperature. Saturated rGOAs were readily regenerated by a brief heat-treatment at 100 °C. This study has demonstrated the potential of novel rGOA for applications using adsorbents to remove siloxanes from biogas.


Asunto(s)
Grafito/química , Siloxanos/química , Adsorción , Geles/química , Interacciones Hidrofóbicas e Hidrofílicas , Oxidación-Reducción , Tamaño de la Partícula , Propiedades de Superficie
18.
Carbohydr Polym ; 260: 117803, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712151

RESUMEN

Biofilm-related infections and contamination of biomaterials are major problems in the clinic. These contaminations are frequently caused by Staphylococcus aureus and are a pressing issue for implantable devices, catheters, contact lenses, prostheses, and wound dressings. Strategies to decrease contamination and biofilm related infections are vital for the success of implantable biomaterials. In this context, hyaluronic acid (HA), a naturally derived carbohydrate polymer, known to be biocompatible, degradable, and immunomodulatory, has shown some antimicrobial activity effects. Due to its poor structural stability, crosslinking strategies, and the incorporation of reinforcing fibres in HA gels is required to produce tailored gels for varying applications. Whilst carbon-based reinforcing materials, such as carbon nanofibers (CNF), present some intrinsic antimicrobial activity related to their high surface area, herein, a crosslinking strategy to enhance the mechanical properties and regulate the rate of degradation of HA is presented. We utilise bis-(ß-isocyanatoethyl) disulphide (BIED) as the crosslinker with the gel reinforced using 0.25 wt% CNF. The effects of CNF and BIED on the structural, mechanical, thermal, and swelling behaviour are examined. These new HA derivatives exhibit excellent mechanical properties and are capable of withstanding physiological stresses in vivo. Antimicrobial activity of the HA derivatives were tested against Staphylococcus aureus and the results reveal antibacterial effect. These carbohydrate based materials have potential application on surfaces within clinical settings where staphylococcal contamination is currently an issue.


Asunto(s)
Antibacterianos/química , Ácido Hialurónico/química , Animales , Antibacterianos/farmacología , Biopelículas/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Reactivos de Enlaces Cruzados/química , Geles/química , Ácido Hialurónico/farmacología , Ratones , Células 3T3 NIH , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/fisiología , Temperatura , Resistencia a la Tracción
19.
Carbohydr Polym ; 260: 117816, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712160

RESUMEN

A biaxially stretched cellulose film with high performance was manufactured from ionic liquid solution through an environmentally friendly, cost effective and facile process. As the transverse stretching ratio (TSR) is increased, the tensile strength and elastic modulus of the biaxially stretched cellulose film in transverse direction (TD) are significantly improved and the coefficient of thermal expansion in TD is reduced while the performance achieves balance in the machine direction (MD) and TD. The transverse stretching regulates the microfibril orientation in the gel film from dominantly uniaxial orientation in MD to homogeneous planar orientation. This microfibril orientation may further play a role in the orientation of the chains in the films during gel drying as evidenced from the birefringence and 2D XRD results. These results indicate cellulose film prepared from ionic liquid process could be utilized with improved structural and mechanical properties by biaxial stretching, and thus serves in various applications.


Asunto(s)
Celulosa/química , Líquidos Iónicos/química , Cristalización , Módulo de Elasticidad , Geles/química , Gossypium/metabolismo , Propiedades de Superficie , Resistencia a la Tracción
20.
Carbohydr Polym ; 260: 117823, 2021 May 15.
Artículo en Inglés | MEDLINE | ID: mdl-33712164

RESUMEN

A bio-based pressure-responsive sensor with adjustable structural color is prepared by combining aerogel skeleton of cellulose nanocrystals (CNCs)/poly(ethylene glycol) (PEG) obtained via the ice-templating method with flexible polyacrylamide (PAAM) elastomer. The white aerogel is composed of consecutive ribbons, demonstrating chiral nematic structure. These ribbons are rearranged to be vertical to the force direction, leading to immediate appearance of the structural color when the 3D aerogel transforms to a 2D plane. Helical pitches are regulated by the PEG content that the wavelength of structural color covers up to 178 nm. There is an excellent linear correlation between pressure and transmittance of reflectance peak, and the sensitivity to pressure can be regulated by changing solid content of PAAM. Furthermore, the pressure-responsive color is still vivid after 16 cycles of compression. This flexible material with pressure-responsive structural color is promising in sensing, intelligent display, information transmission, and etc.


Asunto(s)
Técnicas Biosensibles/métodos , Geles/química , Presión , Resinas Acrílicas/química , Celulosa/química , Fuerza Compresiva , Nanopartículas/química , Polietilenglicoles/química
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