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1.
Pediatr Rheumatol Online J ; 22(1): 3, 2024 Jan 02.
Artículo en Inglés | MEDLINE | ID: mdl-38166934

RESUMEN

BACKGROUND: Patients with rheumatological diseases are at high risk of developing irreversible fibrotic changes, both articular and extra-articular, as a result of tissue damage caused by the chronic phase of persistent inflammation. Thus, our purpose was to study early markers of fibrosis formation in children with juvenile idiopathic arthritis (JIA). METHODS: Seventy patients with juvenile idiopathic arthritis, namely, polyarthritis (64.29%) and oligoarthritis (35.71%) variant JIA (mean age 13.3 years, 64.29% girls, 35.71% boys), were included in this 4-year prospective study. Basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) levels were determined by ELISA kits. RESULTS: We evaluated bFGF (mean: 7478.21 pg/ml; min: 4171.56 pg/ml; max: 18,011.25 pg/ml) and VEGF (mean: 342.47 pg/ml; min: 23.68 pg/ml; max: 2158.91 pg/ml) levels in children with JIA. Children with JIA had a higher VEGF level when JIA onset occurred after 15 years of age and they had a high disease activity; additionally, a higher bFGF level was observed in children older than 14 years and in those with a JIA onset after 15 years of age, the oligoarticular variant, a moderate disease activity and regardless of MTX administration but more often when MTX was administered at a dosage from 10 to 12.5 mg/m2/week. CONCLUSIONS: Laboratory screening of fibrosis formation predictors could help identify patients who may be at greater risk of adverse outcomes. Children with JIA had higher bFGF and VEGF levels when JIA onset occurred after 15 years of age, depending on disease activity.


Asunto(s)
Artritis Juvenil , Niño , Masculino , Femenino , Humanos , Adolescente , Artritis Juvenil/complicaciones , Artritis Juvenil/tratamiento farmacológico , Artritis Juvenil/diagnóstico , Factor A de Crecimiento Endotelial Vascular , Proyectos Piloto , Estudios Prospectivos , Fibrosis
2.
Gels ; 9(12)2023 Nov 29.
Artículo en Inglés | MEDLINE | ID: mdl-38131923

RESUMEN

This work is devoted to the description of the synthesis of hydrogels in the process of cryotropic gel formation based on copolymerization of synthesized potassium 3-sulfopropyl methacrylate and 2-hydroxyethyl methacrylate (SPMA-co-HEMA) and assessing the potential possibility of their use as substrates for growing plants in intensive light culture in a greenhouse. Gel substrates based on the SPMA-co-HEMA were created in two compositions, differing from each other in the presence of macro- and microelements, and their effects were studied on the plants' physiological state (content of chlorophylls a and b, activity of catalase and peroxidase enzymes, intensity of lipid peroxidation, elemental compositions) at the vegetative period of their development and on the plants' growth, productivity and quality of plant production at the final stages of development. Experiments were carried out under controlled microclimate conditions. Modern and standard generally accepted methods of gels were employed (ATR-FTIR and 13C NMR spectral studies, scanning electron microscopy, measurement of specific surface area and pore volume), as well as the methods of the physiological and chemical analysis of plants. The study demonstrated the swelling ability of the created gel substrates. Hydrogels' structure, their specific surface area, porosity, and pore volume were investigated. Using the example of representatives of leaf, fruit and root vegetable crops, the high biological activity of gel substrates was revealed throughout the vegetation period. Species specificity in the reaction of plants to the presence of gel substrates in the root-inhabited environment was revealed. Lettuce, tomato and cucumber plants were more responsive to the effect of the gel substrate, and radish plants were less responsive. At the same time, more pronounced positive changes in plant growth, quality and productivity were observed in cucumber and lettuce in the variant of gel substrates with macro- and microelements and in tomato plants in both variants of gel substrates. Further research into the mechanisms of the influence of gel substrates on plants, as well as the synthesis of new gel substrates with more pronounced properties to sorb and retain moisture is promising.

3.
Wiad Lek ; 76(10): 2302-2307, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37948730

RESUMEN

OBJECTIVE: The aim: To investigate the epidemiological and clinical characteristics of COVID-19 in children for the period 2020-2022. PATIENTS AND METHODS: Materials and methods: A retrospective analysis of 1144 case histories of children who were hospitalized at the St. Zinaida Children's Clinical Hospital (Sumy, Ukraine) for coronavirus disease for 2020-2022 was carried out. The observed patients were divided into 3 groups corresponding to the 3 waves of the pandemic: group 1 - 120 children, group 2 - 311 children, and group 3 - 713. The diagnosis of COVID-19 was established based on clinical, medical histories, laboratory and instrumental data. The etiology of coronavirus disease was determined based on the detection of antigens of the SARS-CoV-2 virus using PCR reverse transcription of a nasopharyngeal swab. RESULTS: Results: An analysis of the clinical and epidemiological indicators of children who were treated for COVID-19 during 2020-2022 was conducted, depending on the outbreak of the pandemic. The frequency of lesions in children of different age groups was determined, and the main clinical symptoms and the frequency of complications in the form of pneumonia during different waves of COVID-19 were determined. CONCLUSION: Conclusions: The incidence of coronavirus infection was mainly observed in children of the younger group (0-5 years). A more severe course of the disease and a higher frequency of complications in the form of pneumonia in children were determined during the 3rd wave of the COVID-19 pandemic.


Asunto(s)
COVID-19 , Humanos , Niño , COVID-19/epidemiología , SARS-CoV-2 , Estudios Retrospectivos , Pandemias , Reacción en Cadena de la Polimerasa
4.
Polymers (Basel) ; 15(19)2023 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-37836006

RESUMEN

Annual bone grafting surgeries due to bone fractures, resections of affected bones, skeletal anomalies, osteoporosis, etc. exceed two million worldwide. In this regard, the creation of new materials for bone tissue repair is one of the urgent tasks of modern medicine. Additive manufacturing, or 3D printing, offers great opportunities for the development of materials with diverse properties and designs. In this study, the one-pot technique for the production of 3D scaffolds based on poly(ε-caprolactone) (PCL) loaded with an antibiotic or anti-inflammatory drug was proposed. In contrast to previously described methods to prepare drug-containing scaffolds, drug-loaded PCL scaffolds were prepared by direct 3D printing from a polymer/drug blend. An investigation of the mechanical properties of 3D-printed scaffolds containing 0.5-5 wt% ciprofloxacin (CIP) or dexamethasone (DEX) showed almost no effect of the drug (compression modulus ~70-90 MPa) compared to unfilled PCL (74 MPa). At the same time, introducing the drug and increasing its content in the PCL matrix contributed to a 1.8-6.8-fold decrease in the specific surface area of the scaffold, depending on composition. The release of CIP and DEX in phosphate buffer solution and in the same buffer containing lipase revealed a faster release in enzyme-containing medium within 45 days. Furthermore, drug release was more intensive from scaffolds with a low drug load. Analysis of the release profiles using a number of mathematical dissolution models led to the conclusion that diffusion dominates over other probable factors. In vitro biological evaluation of the scaffolds containing DEX showed moderate toxicity against osteoblast-like and leukemia monocytic cells. Being 3D-printed together with PCL both drugs retain their biological activity. PCL/CIP and PCL/DEX scaffolds demonstrated antibacterial properties against Pseudomonas aeruginosa (a total inhibition after 48 h) and anti-inflammatory activity in experiments on TNFα-activated monocyte cells (a 4-time reduction in CD-54 expression relative to control), respectively.

5.
Langmuir ; 39(28): 9952-9962, 2023 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-37427431

RESUMEN

Responsive photonic crystals assembled from colloidal particles have been increasingly utilized in detection and sensing devices owing to their attractive ability to change color in response to external conditions. Methods of semi-batch emulsifier-free emulsion and seed copolymerization are successfully applied for the synthesis of monodisperse submicron particles with a core/shell structure, a core being formed by polystyrene or poly(styrene-co-methyl methacrylate) and a shell being formed by poly(methyl methacrylate-co-butyl acrylate). The particle shape and diameter are analyzed by the dynamic light scattering method and scanning electron microscopy, and the composition is investigated by ATR-FTIR spectroscopy. As shown by scanning electron microscopy and optical spectroscopy, the thin-film 3D-ordered structures based on poly(styrene-co-methyl methacrylate)@poly(methyl methacrylate-co-butyl acrylate) particles exhibited the properties of photonic crystals with minimum number of defects. For polymeric photonic crystal structures based on core/shell particles, a pronounced solvatochromism with respect to ethanol vapor (less than 10 vol %) is observed. Moreover, the nature of the crosslinking agent has a significant effect on the solvatochromic properties of 3D-ordered films.

6.
Soft Matter ; 19(22): 4144-4154, 2023 Jun 07.
Artículo en Inglés | MEDLINE | ID: mdl-37249322

RESUMEN

Conducting polymer polyelectrolyte microspheres are typically composed of a cationic conducting polymer and an anionic polymer. The polymer chains inside these microspheres are physically or chemically cross-linked, creating a network that enables high water retention. Poly(3,4-ethylenedioxythiophene) (PEDOT) being an electrically conductive polymer exhibits a high conductivity and has great biotechnological applications. The unique combination of properties of PEDOT containing polyelectrolyte microspheres makes them widely investigated materials for electroresponsive cells, tissue engineering, and bio-sensors. The demand to produce PEDOT with varied properties depending the specific application requires the understanding of the basic principles of template formation. In the present work, we studied the inverse suspension polymerization of p-styrenesulfonic acid in the presence of a cross-linking agent as a synthetic way for the formation of porous polyelectrolyte microspheres. We traced how the nature of the emulsifier affected both the structure of the surface layer of the microspheres and the degree of their cross-linking. The porous structure of polyelectrolyte microspheres obtained is found to promote the polymerization of EDOT in their presence throughout the entire microsphere volume. The structural characteristics of the polyelectrolyte/PEDOT complexes in relation to their electrochemical properties have been studied.

7.
Int J Mol Sci ; 24(3)2023 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-36769272

RESUMEN

Polymeric hydrogels based on sulfo-containing comonomers are promising materials for biotechnological application, namely, for use as a system for delivering water and minerals during seed germination in conditions of an unstable moisture zone. In this work, cryogels based on 3-sulfopropyl methacrylate and 2-hydroxyethyl methacrylate copolymers were obtained by the cryotropic gelation method. The morphology, specific surface area, and swelling behaviors of cryogels are found to depend on the total concentration of monomers in the reaction system and the content of the gel fraction in cryogels. Cryogels formed in the presence of nanodiamonds are shown to exhibit high biological activity during the germination of Lepidium sativum L. variety Ajur seeds, which manifests itself by stimulating seed germination and a significant increase in the raw weight of sprouts. These results indicate that sulfonic cryogels have a high potential to improve seed germination and plant growth, proving that such cryogels can be used as environmentally friendly materials for agricultural applications.


Asunto(s)
Biotecnología , Criogeles , Polímeros , Agua
8.
Molecules ; 27(21)2022 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-36364406

RESUMEN

Conductive hydrogels are polymeric materials that are promising for bioelectronic applications. In the present study, a complex based on sulfonic cryogels and poly(3,4-ethylenedioxythiophene) (PEDOT) was investigated as an example of a conductive hydrogel. Preparation of polyacrylate cryogels of various morphologies was carried out by cryotropic gelation of 3-sulfopropyl methacrylate and sulfobetaine methacrylate in the presence of functional comonomers (2-hydroxyethyl methacrylate and vinyl acetate). Polymerization of 3,4-ethylenedioxythiophene in the presence of several of the above cryogels occurred throughout the entire volume of each polyelectrolyte cryogel because of its porous structure. Structural features of cryogel@PEDOT complexes in relation to their electrochemical properties were investigated. It was shown that poly(3,4-ethylenedioxythiophene) of a linear conformation was formed in the presence of a cryogel based on sulfobetaine methacrylate, while minimum values of charge-transfer resistance were observed in those complexes, and electrochemical properties of the complexes did not depend on diffusion processes.


Asunto(s)
Criogeles , Metacrilatos , Criogeles/química , Polimerizacion , Polielectrolitos , Metacrilatos/química
9.
Sensors (Basel) ; 22(7)2022 Apr 05.
Artículo en Inglés | MEDLINE | ID: mdl-35408397

RESUMEN

The main task of the research is to acquire fundamental knowledge about the effect of polymer structure on the physicochemical properties of films. A novel meta-material that can be used in manufacturing sensor layers was developed as a model. At the first stage, poly(sodium 4-styrenesulfonate) (PNaSS) cross-linked microspheres are synthesized (which are based on strong polyelectrolytes containing sulfo groups in each monomer unit), and at the second stage, PNaSS@PEDOT microspheres are formed. The poly(3,4-ethylenedioxythiophene) (PEDOT) shell was obtained by the acid-assisted self-polymerization of the monomer; this process is biologically safe and thus suitable for biomedical applications. The suitability of electrochemical impedance spectroscopy for E. coli detection was tested; it was revealed that the attached bacterial wall was destroyed upon application of constant oxidation potential (higher than 0.5 V), which makes the PNaSS@PEDOT microsphere particles promising materials for the development of antifouling coatings. Furthermore, under open-circuit conditions, the walls of E. coli bacteria were not destroyed, which opens up the possibility of employing such meta-materials as sensor films. Scanning electron microscopy, X-ray photoelectron spectroscopy, water contact angle, and wide-angle X-ray diffraction methods were applied in order to characterize the PNaSS@PEDOT films.


Asunto(s)
Escherichia coli , Polímeros , Compuestos Bicíclicos Heterocíclicos con Puentes/química , Microesferas , Polímeros/química
10.
Int J Biol Macromol ; 206: 614-620, 2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35219778

RESUMEN

The fucoidan SdeF was isolated from brown alga Saccharina dentigera. The structure of the obtained polysaccharide was studied by chemical methods, NMR spectroscopy of the fully and partially desulfated derivatives, and mass spectrometry of the fucoidan fragments, labeled with 18O. The SdeF was shown to be sulfated (40%) 1,3-linked α-L-fucan, with branches at C2. The sulfate groups were found at positions C2 and C4. Derivatives SdeFDS and SdeFPL were obtained by solvolytic desulfation and autohydrolysis of SdeF, respectively. According to 13C NMR data, SdeFDS is 1,3-linked α-L-fucan, while SdeFPL is 4-sulfated 1,3-linked α-L-fucan. Native fucoidan SdeF was shown to be a non-toxic anticancer substance in the model of human malignant melanoma RPMI-7951, colorectal adenocarcinoma HCT-116, and small intestine adenocarcinoma HuTu 80 cells. The partial desulfation of SdeF at C2 and/or the reduction of its Mw, from 229 to 28 kDa, decreased the anticancer activity; complete removal of the sulfated groups and/or Mw reduction to 4.7 kDa further reduced the effect of this polysaccharide.


Asunto(s)
Adenocarcinoma , Antineoplásicos , Phaeophyceae , Antineoplásicos/química , Antineoplásicos/farmacología , Humanos , Phaeophyceae/química , Polisacáridos/química , Polisacáridos/farmacología , Sulfatos
11.
Carbohydr Polym ; 273: 118551, 2021 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-34560963

RESUMEN

Fucoidans are biologically active sulfated polysaccharides of brown algae. They have a great structural diversity and a wide spectrum of biological activity. This review is intended to outline what is currently known about the structures of fucoidans and their radioprotective effect. We classified fucoidans according to their composition and structure, examined the structure of fucoidans of individual representatives of algae, summarized the available data on changes in the yields and compositions of fucoidans during algae development, and focused on information about underexplored radioprotective effect of these polysaccharides. Based on the presented in the review data, it is possible to select algae, which are the sources of fucoidans of desired structures and to determine the best time to harvest them. The use of high purified polysaccharides with established structures increase the value of studies of their biological effects and the determination of the dependence "structure - biological effect".


Asunto(s)
Polisacáridos/química , Polisacáridos/farmacología , Protectores contra Radiación/farmacología , Animales , Apoptosis/efectos de los fármacos , Células de la Médula Ósea/metabolismo , Galactosa/análisis , Humanos , Estructura Molecular , Phaeophyceae/química , Protectores contra Radiación/química , Sulfatos/química
12.
Int J Biol Macromol ; 185: 679-687, 2021 Aug 31.
Artículo en Inglés | MEDLINE | ID: mdl-34216666

RESUMEN

Chitosan/fucoidan nanoparticles were created using two fucoidans from the Fucus evanescens algae. One of them was a regular fucoidan obtained for the first time from the alga harvested at the reproductive growth stage, using only standard extraction methods, without additional modifications. Its structure was established via NMR spectroscopy to consist of the repeating →3)-α-L-Fucp-(2,4SO3-)-(1 â†’ 4)-α-L-Fucp-(2SO3-)-(1→ fragment. Such fragment also coustituted 55% of the other fucoidan's structure, however it also included long sequences of α-L-fucopyranose residues sulfated only at C2. The nanoparticles were re-dispersed in water and the influence of fucoidan/chitosan mass ratio on the nanoparticles' size and zeta potential was investigated. 3D models of the regular fucoidan and chitosan's sections were created and their molecular docking was performed, showing that either polymer could occupy the exterior of the complex, depending on their ratio. Thermodynamic parameters of fucoidan-chitosan binding process were accessed, with the results indicating that significant conformational changes of fucoidan and chitosan molecules take place during the interaction, presumably to allow for more effective binding.


Asunto(s)
Quitosano/química , Fucus/química , Polisacáridos/química , Conformación de Carbohidratos , Secuencia de Carbohidratos , Simulación del Acoplamiento Molecular , Nanopartículas , Tamaño de la Partícula , Agua/química
13.
Int J Biol Macromol ; 183: 1427-1435, 2021 Jul 31.
Artículo en Inglés | MEDLINE | ID: mdl-34023368

RESUMEN

The aim of this study was to establish the fine structure of fucoidan from Sargassum oligocystum and to study the radiosensitizing effect of fucoidans from three algae of genus Sargassum (S. oligocystum, S. duplicatum, and S. feldmannii) with different structures. The fucoidan SoF2 from S. oligocystum was sulfated (32%) galactofucan (Fuc:Gal = 2:1), with a Mw of 183 kDa (Mw/Mn = 2.0). Its supposed structure was found to be predominantly 1,3-linked fucose as the main chain, with branching points at C2 and C4. The branches could be single galactose and/or fucose short chains with terminal galactose residues. Sulfate groups were found at positions C3, C2, and/or C4 of fucose residues and at C2 and/or C4 of galactose residues. The radiosensitizing effect of galactofucans from S. oligocystum, S. duplicatum, and S. feldmannii against human melanoma SK-MEL-28, colon HT-29, and breast MDA-MB-231 cancer cells was investigated. The influence of all investigated polysaccharides treatments with/without X-ray radiation on colony formation of human melanoma cells SK-MEL-28 was weak. Fucoidan from S. feldmannii has been shown to be the most promising radiosensitizing compound against human colon HT-29 and breast MDA-MB-231 cancer cells.


Asunto(s)
Polisacáridos/química , Sargassum/química , Línea Celular Tumoral , Células HT29 , Humanos , Fármacos Sensibilizantes a Radiaciones/química
14.
Soft Matter ; 17(8): 2290-2301, 2021 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-33475667

RESUMEN

Polyelectrolyte microspheres find applications in many fields such as ion exchange columns, fuel cell membranes, and catalysis, to name a few. Synthesis of these microspheres by inverse emulsion polymerization offers various advantages due to the increased specific surface area and high surface charge density. The surface charge density of the obtained polyelectrolyte microspheres is a hundred times higher than that of either particles obtained by dispersion copolymerization of styrene and styrenesulfonic acid or sulfonated microspheres. The morphology, chemical structure, and electro-surface properties of the synthesized microspheres were studied by transmission and scanning electron microscopy, FTIR-spectroscopy, and conductometric and potentiometric titrations, respectively. Using the potentiometric titration it is possible to characterize the structure of the surface layer of polyelectrolyte microspheres as entirely as possible. The study of the ion-exchange capacity of polyelectrolyte microspheres shows that ion-exchange capacity is 2.1 meq g-1 in this case, which is more than 2 times higher than that of sulfonated microspheres, and 20 times higher than that of particles obtained by dispersion copolymerization.

15.
Carbohydr Polym ; 250: 116921, 2020 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-33049835

RESUMEN

Polysaccharide fractions of alginate, laminarans and fucoidans were obtained from the brown alga Tauya basicrassa. Yields of alginate and laminarans were large (19.7 % and 5.62 %, respectively), whereas the content of fucoidans (0.52 %) was not significant. Alginate and laminarans had typical structures for those substances. Fucoidans were low- and medium-sulfated heterogeneous polysaccharides. The fucoidan fraction 1TbF1 was sulfated fucogalactan containing a backbone from 1,6-linked residues of ß-d-galactopyranose with branches at C3 and C4, terminal fucose and galactose residues and fragments from 1,3-; 1,4-; and 1,2-fucose residues. Sulfate groups were found at positions 2 and 4 of fucose, and positions 2, 3 and 4 of galactose residues. Laminaran 2TbL was subjected to a sulfation to obtain the derivative 2TbLS with partial sulfation (46 %) at C2, C4 and C6. It was shown that 2TbL and 2TbLS inhibited colony formation of sensitize-tested colon cancer cells HT-29 and HCT-116 to X-ray radiation.


Asunto(s)
Neoplasias del Colon/tratamiento farmacológico , Glucanos/farmacología , Phaeophyceae/química , Polisacáridos/química , Fármacos Sensibilizantes a Radiaciones/farmacología , Sulfatos/química , Antineoplásicos , Neoplasias del Colon/patología , Glucanos/química , Humanos , Polisacáridos/farmacología , Fármacos Sensibilizantes a Radiaciones/química , Células Tumorales Cultivadas , Rayos X
16.
J Microencapsul ; 37(6): 457-465, 2020 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-32552377

RESUMEN

Droplet microfluidics offers exquisite control over the flows of multiple fluids in micro-scale, enabling fabrication of advanced microspheres with precisely tuneable structures. The main goal of this work was to design monodispersed carboxylated polystyrene microspheres with a developed pore structure (a specific surface area more than 200 m2/g) using microfluidic technology. We investigated the influence of the composition of monomer phase for the stable formation of droplets. Under the stable region, the resulting microspheres (with diameter 50 µm) showed narrow size distribution having a coefficient of variation of below 2%. The obtained microspheres are characterised by morphology and surface structure by means of electron microscopy. The structure of cross-linked microspheres is investigated by solid-state 1H NMR spectroscopy. Finally, these microspheres have great potential for the effective sorption of biologically active substances (bovine serum albumin).


Asunto(s)
Microfluídica/métodos , Microesferas , Poliestirenos/química , Albúmina Sérica Bovina/química , Porosidad
17.
Carbohydr Polym ; 221: 157-165, 2019 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-31227154

RESUMEN

The sulfated α-l-fucans ScF and LlF were obtained from brown algae of the Laminariaceae family (Saccharina cichorioides and Laminaria longipes). According to spectroscopy NMR, the LlF fucan predominantly contained the →3)-α-l-Fucp-(2SO3-)-(1→4)-α-l-Fucp-(1→2)-α-l-Fucp-(4SO3-)-(1→ repeating units, with small amounts of disaccharide 1,4-linked fragments and 3-sulfated fucose residues. Mass spectrometric analysis revealed the presence of the following fragments in the fucan structure: α-l-Fucp-(2SO3-)-(1→4)-α-l-Fucp-(2SO3-)-(1→3)-α-l-Fucp-(4SO3-); α-l-Fucp-(2,4SO3-)-(1→3)-α-l-Fucp-(1→3)-α-l-Fucp-(4SO3-); α-l-Fucp-(2SO3-)-(1→2)-α-l-Fucp; α-l-Fucp-(2SO3-)-(1→2)-α-l-Fucp-(4SO3-); α-l-Fucp-(2SO3-)-(1→3)-α-l-Fucp; α-l-Fucp-(2,4SO3-)-(1→3)-α-l-Fucp; α-l-Fucp-(4SO3-)-(1→4)-α-l-Fucp; and α-l-Fucp-(4SO3-)-(1→4)-α-l-Fucp-(2SO3-). Both ScF and LlF fucoidans inhibited colony formation and growth of melanoma and colon cancer cells and sensitize-tested cancer cells to X-ray radiation to a comparable degree.


Asunto(s)
Antineoplásicos/farmacología , Laminaria/química , Polisacáridos/farmacología , Fármacos Sensibilizantes a Radiaciones/farmacología , Antineoplásicos/química , Secuencia de Carbohidratos , Línea Celular Tumoral , Humanos , Polisacáridos/química , Fármacos Sensibilizantes a Radiaciones/química
18.
JOM (1989) ; 71(1): 48-58, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30880880

RESUMEN

This article presents a novel coupling of numerical techniques that enable three-dimensional convection-driven microstructure simulations to be conducted on practical time scales appropriate for small-size components or experiments. On the microstructure side, the cellular automata method is efficient for relatively large-scale simulations, while the lattice Boltzmann method provides one of the fastest transient computational fluid dynamics solvers. Both of these methods have been parallelized and coupled in a single code, allowing resolution of large-scale convection-driven solidification problems. The numerical model is validated against benchmark cases, extended to capture solute plumes in directional solidification and finally used to model alloy solidification of an entire differentially heated cavity capturing both microstructural and meso-/macroscale phenomena.

19.
Int J Biol Macromol ; 124: 220-228, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30496854

RESUMEN

Fucoidans are valuable biologically active polysaccharides of brown algae. The aim of this study was to investigate the structure of fucoidan from Sargassum feldmannii and the anticancer effects of native and modified polysaccharides from S. feldmannii and S. duplicatum. The structure of sulfated (25.3%) galactofucan SfF2 (Fuc/Gal = 72/28 mol%) from S. feldmannii was investigated by NMR spectroscopy of desulfated derivative and mass spectrometry of fucoidan fragments labelled with 18O. SfF2 was shown to contain the main chain from 1,3-linked α-l-fucopyranose and ß-d-galactopyranose residues with fucose branches at C4 and C6 of galactose residues and C2 of fucose residues. The following fragments were also identified in SfF2: Fuc-(1,4)-Fuc, Gal-(1,3)-Gal, and Gal-(1,4)-Gal. The sulfate groups occupied positions C2, C3, and C4 of fucose residues and C2, C3, C4, and C6 of galactose residues. The galactofucans from S. feldmannii, S. duplicatum, and their derivatives exhibited no cytotoxicity in vitro. The native and deacetylated fucoidans (200 µg/mL) inhibited colony formation of human colon cancer cells (DLD-1, HT-29, and HCT-116). Both desulfated fucoidans possessed weak anticancer activity.


Asunto(s)
Antineoplásicos/química , Polisacáridos/química , Sargassum/química , Antineoplásicos/aislamiento & purificación , Antineoplásicos/farmacología , Neoplasias del Colon/tratamiento farmacológico , Galactosa/química , Células HT29 , Humanos , Polisacáridos/aislamiento & purificación , Polisacáridos/farmacología , Sulfatos/química
20.
Int J Biol Macromol ; 117: 1101-1109, 2018 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-29885396

RESUMEN

In the present study, three sulfated polysaccharides, two fractions of fucosylated chondroitin sulfates, and one sulfated fucan were isolated from the body wall of the Vietnamese sea cucumber Stichopus variegatus. The structure of the sulfated fucan fraction SvF3 from S. variegatus was investigated for the first time. According to NMR spectroscopy data, the sulfated fucan SvF3 contained 1,2- and 1,3-linked α-l-fucopyranose residues. Sulfate groups were found at the 2 and/or 4 positions. The structural analysis of fucoidan was assisted by tandem mass spectrometry; the recently-developed technique of autohydrolysis in heavy­oxygen water for the obtaining of selectively labeled fucoidan fragments was applied. The labeling (+2 Da mass shift at the reducing end) allowed us to assign MS/MS data unambiguously, and thus to confirm the NMR data and revealed minor sulfation at position 3. It was shown that the sulfated fucan SvF3 was not cytotoxic to human breast cancer T-47D and MDA-MB-231 cell lines, and it inhibited colony formation of those cells in vitro. SvF3 also possessed slight activity against migration of MDA-MB-231 cells in vitro.


Asunto(s)
Antineoplásicos/química , Antineoplásicos/farmacología , Polisacáridos/química , Polisacáridos/farmacología , Animales , Antineoplásicos/aislamiento & purificación , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Hidrólisis , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Peso Molecular , Polisacáridos/aislamiento & purificación , Pepinos de Mar/química , Relación Estructura-Actividad , Temperatura
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