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1.
Braz Dent J ; 35: e245461, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38775590

RESUMO

This study aimed to evaluate the osteogenic potential of hydroxyapatite (HA), Alginate (Alg), and Gelatine (Gel) composite in a critical-size defect model in rats. Twenty-four male rats were divided into three groups: a negative control with no treatment (Control group), a positive control treated with deproteinized bovine bone mineral (DBBM group), and the experimental group treated with the new HA-Alg-Gel composite (HA-Alg-Gel group). A critical size defect (8.5mm) was made in the rat's calvaria, and the bone formation was evaluated by in vivo microcomputed tomography analysis (µCT) after 1, 15, 45, and 90 days. After 90 days, the animals were euthanized and histological and histomorphometric analyses were performed. A higher proportion of mineralized tissue/biomaterial was observed in the DBBM group when compared to the HA-Alg-Gel and Control groups in the µCT analysis during all analysis periods. However, no differences were observed in the mineralized tissue/biomaterial proportion observed on day 1 (immediate postoperative) in comparison to later periods of analysis in all groups. In the histomorphometric analysis, the HA-Alg-Gel and Control groups showed higher bone formation than the DBBM group. Moreover, in histological analysis, five samples of the HA-Alg-Gal group exhibited formed bone spicules adjacent to the graft granules against only two of eight samples in the DBBM group. Both graft materials ensured the maintenance of defect bone thickness, while a tissue thickness reduction was observed in the control group. In conclusion, this study demonstrated the osteoconductive potential of HA-Alg-Gel bone graft by supporting new bone formation around its particles.


Assuntos
Alginatos , Regeneração Óssea , Durapatita , Gelatina , Crânio , Microtomografia por Raio-X , Animais , Regeneração Óssea/efeitos dos fármacos , Durapatita/farmacologia , Crânio/cirurgia , Crânio/diagnóstico por imagem , Ratos , Masculino , Materiais Biocompatíveis , Ácido Glucurônico , Ratos Wistar , Ácidos Hexurônicos , Osteogênese/efeitos dos fármacos , Substitutos Ósseos
2.
Int J Biol Macromol ; 269(Pt 1): 132084, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38719003

RESUMO

Pseudomonas aeruginosa biofilm enhances tolerance to antimicrobials and immune system defenses. Alginate is an important component of biofilm and a virulence factor of P. aeruginosa. The degradation of alginate by alginate lyases has come to serve as an adjunctive therapeutic strategy against P. aeruginosa biofilm, but poor stability of the enzyme limited this application. Thus, PspAlgL, an alginate lyase, can degrade acetylated alginate but has poor thermostability. The 3D structure of PspAlgL was predicted, and the thermostability of PspAlgL was rationally designed by GRAPE strategy, resulting in two variants with better stability. These variants, PspAlgLS270F/E311P and PspAlgLG291S/E311P, effectively degraded the alginate in biofilm. In addition, compared with PspAlgL, these variants were more efficient in inhibiting biofilm formation and degrading the established biofilm of P. aeruginosa PAO1, and they were also able to destroy the biofilm attached to catheters and to increase the sensitivity of P. aeruginosa to the antibiotic amikacin. This study provides one potential anti-biofilm agent for P. aeruginosa infection.


Assuntos
Alginatos , Antibacterianos , Biofilmes , Polissacarídeo-Liases , Pseudomonas aeruginosa , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Pseudomonas aeruginosa/efeitos dos fármacos , Alginatos/química , Alginatos/farmacologia , Polissacarídeo-Liases/química , Polissacarídeo-Liases/metabolismo , Antibacterianos/farmacologia , Antibacterianos/química , Estabilidade Enzimática , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Temperatura , Ácido Glucurônico/química , Ácido Glucurônico/farmacologia , Modelos Moleculares
3.
Plant Physiol Biochem ; 211: 108694, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38714131

RESUMO

Using natural clinoptilolite (NCP) as a carrier and alginate (Alg)-calcium as an active species, the porous silicon calcium alginate nanocomposite (Alg-Ca-NCP) was successfully fabricated via adsorption-covalence-hydrogen bond. Its structural features and physicochemical properties were detailed investigated by various characterizations. The results indicated that Alg-Ca-NCP presented the disordered lamellar structures with approximately uniform particles in size of 300-500 nm. Specially, their surface fractal evolutions between the irregular roughness and dense structures were demonstrated via the SAXS patterns. The results elucidated that the abundant micropores of NCP were beneficial for unrestricted diffusing of Alg-Ca, which was conducive to facilitate a higher loading and sustainable releasing. The Ca content of leaf mustard treated with Alg-Ca-NCP-0.5 was 484.5 mg/100g on the 21st day, higher than that by water (CK) and CaCl2 solution treatments, respectively. Meanwhile, the prepared Alg-Ca-NCPs presented the obvious anti-aging effects on peroxidase drought stress of mustard leaves. These demonstrations provided a simple and effective method to synthesize Alg-Ca-NCPs as delivery nanocomposites, which is useful to improve the weak absorption and low utilization of calcium alginate by plants.


Assuntos
Alginatos , Mostardeira , Zeolitas , Alginatos/química , Alginatos/farmacologia , Zeolitas/química , Zeolitas/farmacologia , Mostardeira/metabolismo , Mostardeira/efeitos dos fármacos , Mostardeira/química , Folhas de Planta/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/química , Porosidade , Brassica/metabolismo , Brassica/efeitos dos fármacos , Brassica/crescimento & desenvolvimento , Ácido Glucurônico/química , Nanocompostos/química , Difração de Raios X , Ácidos Hexurônicos/química , Ácidos Hexurônicos/metabolismo
4.
Exp Dermatol ; 33(5): e15098, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38770557

RESUMO

Healing of complex wounds requires dressings that must, at least, not hinder and should ideally promote the activity of key healing cells, in particular fibroblasts. This in vitro study assessed the effects of three wound-dressings (a pure Ca2+ alginate: Algostéril®, a Ca2+ alginate + carboxymethylcellulose: Biatain alginate® and a polyacrylate impregnated with lipido-colloid matrix: UrgoClean®) on dermal fibroblast activity. The results showed the pure calcium alginate to be non-cytotoxic, whereas the other wound-dressings showed moderate to strong cytotoxicity. The two alginates stimulated fibroblast migration and proliferation, whereas the polyacrylate altered migration and had no effect on proliferation. The pure Ca2+ alginate significantly increased the TGF-ß-induced fibroblast activation, which is essential to healing. This activation was confirmed by a significant increase in Vascular endothelial growth factor (VEGF) secretion and a higher collagen production. The other dressings reduced these fibroblast activities. The pure Ca2+ alginate was also able to counteract the inhibitory effect of NK cell supernatants on fibroblast migration. These in vitro results demonstrate that tested wound-dressings are not equivalent for fibroblast activation. Only Algostéril was found to promote all the fibroblast activities tested, which could contribute to its healing efficacy demonstrated in the clinic.


Assuntos
Alginatos , Movimento Celular , Proliferação de Células , Fibroblastos , Fator A de Crescimento do Endotélio Vascular , Cicatrização , Fibroblastos/efeitos dos fármacos , Cicatrização/efeitos dos fármacos , Humanos , Alginatos/farmacologia , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Fator A de Crescimento do Endotélio Vascular/metabolismo , Colágeno/metabolismo , Bandagens , Fator de Crescimento Transformador beta/metabolismo , Carboximetilcelulose Sódica , Células Cultivadas , Células Matadoras Naturais/efeitos dos fármacos , Resinas Acrílicas , Ácidos Hexurônicos , Ácido Glucurônico , Pele
5.
J Biosci Bioeng ; 137(6): 463-470, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38570220

RESUMO

The choice of sterilization method for hydrogels used for cell culture influences the ease of preparing the gel. We prepared interpenetrating gelatin/calcium alginate hydrogels containing 1% (w/v) alginate and 1-16% (w/v) gelatin by molding with the mixture of gelatin/sodium alginate solution, followed by the addition of calcium ions by incubation in calcium chloride solution. It is the simplest method to prepare autoclavable gelatin/sodium hydrogel. We measured various properties of the hydrogels including volume, Young's modulus in the compression test, storage modulus, and loss modulus in the dynamic viscoelasticity measurement. The gelatin/alginate hydrogel can be easily fabricated into any shape by this method. After autoclave treatment, the hydrogel was shrunk to smaller than the original shape in similar figures. The shape of the gelatin/alginate hydrogel can be designed into any shape with the reduction ratio of the volume. Human osteosarcoma (HOS) cells adhered to the gelatin/alginate hydrogel and then proliferated. Gelatin/calcium alginate hydrogels with a high concentration are considered to be autoclavable culture substrates because of their low deformation and gelatin elution rate after autoclaving and the high amount of cells attached to the hydrogels.


Assuntos
Alginatos , Gelatina , Hidrogéis , Alicerces Teciduais , Gelatina/química , Alginatos/química , Hidrogéis/química , Humanos , Alicerces Teciduais/química , Linhagem Celular Tumoral , Esterilização , Proliferação de Células/efeitos dos fármacos , Ácido Glucurônico/química , Engenharia Tecidual/métodos , Ácidos Hexurônicos/química , Módulo de Elasticidade , Adesão Celular
6.
Tissue Eng Part C Methods ; 30(5): 229-237, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38568845

RESUMO

Modeling organ-blood barriers through the inclusion of microvessel networks within in vitro tissue models could lead to more physiologically accurate results, especially since organ-blood barriers are crucial to the normal function, drug transport, and disease states of vascularized organs. Microvessel networks are difficult to form, since they push the practical limits of most fabrication methods, and it is difficult to coax vascular cells to self-assemble into structures larger than capillaries. Here, we present a method for rapidly forming networks of microvessel-like structures using sacrificial alginate structures. Specifically, we encapsulated endothelial cells within short alginate threads, and then embedded them in collagen gel. Following enzymatic degradation of the alginate, the collagen gel contained a network of hollow channels seeded with cells, all surrounding a perfusable central channel. This method uses a 3D-printed coaxial extruder and syringe pumps to generate short threads in a way that is repeatable and easily transferrable to other labs. The cell-laden, sacrificial alginate threads can be frozen after fabrication and thawed before embedding without significant loss of cell viability. The ability to freeze the threads enables future scale-up and ease of use. Within millifluidic devices that restrict access to media, the threads enhance cell survival under static conditions. These results indicate the potential for use of this method in a range of tissue engineering applications.


Assuntos
Alginatos , Microvasos , Engenharia Tecidual , Alginatos/química , Microvasos/citologia , Humanos , Engenharia Tecidual/métodos , Células Endoteliais da Veia Umbilical Humana/citologia , Células Endoteliais da Veia Umbilical Humana/metabolismo , Alicerces Teciduais/química , Células Endoteliais/citologia , Células Endoteliais/metabolismo , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Sobrevivência Celular , Animais , Colágeno/química
7.
J Gen Virol ; 105(4)2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38656455

RESUMO

Porcine epidemic diarrhea (PED) is a serious disease in piglets that leads to high mortality. An effective measure that provides higher IgA levels in the intestine and milk is required to decrease losses. Porcine epidemic diarrhea virus (PEDV) was dissolved in calcium alginate (Alg) and combined with chitosan (CS) via electrostatic interactions between cationic chitosan and anionic alginate to create a porous gel (Alg-CS+PEDV). The gel was used to immunize mice orally or in combination with subcutaneous injections of inactivated PEDV vaccine. At 12 and 24 days after immunization, levels of IgA and IgG in Alg-CS+PEDV were higher than with normal PEDV oral administration. At 24 days after immunization, the concentration of IFN-γ in Alg-CS+PEDV was higher than with normal PEDV oral administration. Furthermore, oral administration combining subcutaneous immunization induced higher levels of IgG and IgA than oral administration alone. Our study provides a new method for the preparation and administration of oral vaccines to achieve enhanced mucosal immunity against PEDV.


Assuntos
Alginatos , Anticorpos Antivirais , Quitosana , Imunidade nas Mucosas , Imunoglobulina A , Imunoglobulina G , Vírus da Diarreia Epidêmica Suína , Vacinas Virais , Animais , Administração Oral , Vírus da Diarreia Epidêmica Suína/imunologia , Alginatos/administração & dosagem , Quitosana/administração & dosagem , Camundongos , Vacinas Virais/imunologia , Vacinas Virais/administração & dosagem , Anticorpos Antivirais/imunologia , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Suínos , Infecções por Coronavirus/imunologia , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/veterinária , Infecções por Coronavirus/virologia , Vacinas de Produtos Inativados/administração & dosagem , Vacinas de Produtos Inativados/imunologia , Doenças dos Suínos/imunologia , Doenças dos Suínos/prevenção & controle , Doenças dos Suínos/virologia , Feminino , Géis/administração & dosagem , Camundongos Endogâmicos BALB C , Interferon gama/imunologia , Ácido Glucurônico/administração & dosagem , Ácidos Hexurônicos/administração & dosagem
8.
Chem Commun (Camb) ; 60(33): 4495-4498, 2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38567462

RESUMO

We have demonstrated that cisplatin (CP), an anticancer drug, showed a preference for binding the sulfated-L-iduronic acid (S-L-IdoA) unit over the sulfated-D-glucuronic acid unit of heparan sulfate. The multivalency of S-L-IdoA, such as in the proteoglycan mimic, resulted in distinct modes of cell-surface engineering in normal and cancer cells, with these disparities having a significant impact on CP-mediated toxicity.


Assuntos
Cisplatino , Proteoglicanas , Heparitina Sulfato/química , Ácido Glucurônico/metabolismo , Ácido Idurônico , Sulfatos
9.
Carbohydr Polym ; 333: 121976, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38494228

RESUMO

White tea, one of the six traditional teas in China, is made only through natural withering and low-temperature drying processes. It demonstrates diverse pharmacological and health-promoting effects, including antioxidant, antiviral, anticancer, and hypolipidemic activities. Despite the significance of polysaccharides in white tea leaves, their fine structure and physiological functions remain unexplored. In this study, the polysaccharide fragment WTP-80a with anticancer activity was isolated and purified from white tea through water extraction, alcohol precipitation, DEAE-52 ion exchange column chromatography, and sephacryl S-200 dextran gel column chromatography. WTP-80a exhibited a molecular weight of 1.14 × 105 Da and consisted of galactose (Gal), arabinose (Ara), rhamnose (Rha), and glucuronic acid (Glc-UA). The main chain skeleton of WTP-80a contained 3,6)-ß-Galp-(1→, 3)-α-Galp-(1→, 5)-α-Araf-(1 â†’ and 3)-α-Glcp-UA-(1→. Branch chains included α-Araf-(1 â†’ and ß-Rhap-(1 â†’ connected to the C3 and C6 positions of →3,6)-ß-Galp-(1→, respectively. In vitro anticancer experiments revealed that WTP-80a effectively hindered the proliferation, colony formation, migration, and invasion of B16F10 cells. Additionally, it induced apoptosis in B16F10 cells by blocking the G2/M phase, increasing active oxygen content, and reducing mitochondrial membrane potential. These findings provide a solid theoretical foundation for the application of white tea polysaccharides as anticancer products.


Assuntos
Galactose , Polissacarídeos , Polissacarídeos/química , Galactose/análise , Ramnose , Ácido Glucurônico , Chá
10.
J Mater Sci Mater Med ; 35(1): 19, 2024 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-38526655

RESUMO

The efficacy of stem-cell therapy depends on the ability of the transplanted cells to escape early immunological reactions and to be retained at the site of transplantation. The use of tissue engineering scaffolds or injectable biomaterials as carriers has been proposed, but they still present limitations linked to a reliable manufacturing process, surgical practice and clinical outcomes. Alginate microbeads are potential candidates for the encapsulation of mesenchymal stromal cells with the aim of providing a delivery carrier suitable for minimally-invasive and scaffold-free transplantation, tissue-adhesive properties and protection from the immune response. However, the formation of stable microbeads relies on the cross-linking of alginate with divalent calcium ions at concentrations that are toxic for the cells, making control over the beads' size and a single-cell encapsulation unreliable. The present work demonstrates the efficiency of an innovative, high throughput, and reproducible microfluidic system to produce single-cell, calcium-free alginate coatings of human mesenchymal stromal cells. Among the various conditions tested, visible light and confocal microscopy following staining of the cell nuclei by DAPI showed that the microfluidic system yielded an optimal single-cell encapsulation of 2000 cells/min in 2% w/v alginate microcapsules of reproducible morphology and an average size of 28.2 ± 3.7 µm. The adhesive properties of the alginate microcapsules, the viability of the encapsulated cells and their ability to escape the alginate microcapsule were demonstrated by the relatively rapid adherence of the beads onto tissue culture plastic and the cells' ability to gradually disrupt the microcapsule shell after 24 h and proliferate. To mimic the early inflammatory response upon transplantation, the encapsulated cells were exposed to proliferating macrophages at different cell seeding densities for up to 2 days and the protection effect of the microcapsule on the cells assessed by time-lapse microscopy showing a shielding effect for up to 48 h. This work underscores the potential of microfluidic systems to precisely encapsulate cells by good manufacturing practice standards while favouring cell retention on substrates, viability and proliferation upon transplantation.


Assuntos
Células-Tronco Mesenquimais , Microfluídica , Humanos , Encapsulamento de Células , Cápsulas , Medula Óssea , Alginatos/química , Ácidos Hexurônicos/química , Sobrevivência Celular , Ácido Glucurônico/química
11.
Proc Natl Acad Sci U S A ; 121(13): e2400226121, 2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38502690

RESUMO

Glucuronidation is a detoxification process to eliminate endo- and xeno-biotics and neurotransmitters from the host circulation. Glucuronosyltransferase binds these compounds to glucuronic acid (GlcA), deactivating them and allowing their elimination through the gastrointestinal (GI) tract. However, the microbiota produces ß-glucuronidases that release GlcA and reactivate these compounds. Enteric pathogens such as enterohemorrhagic Escherichia coli (EHEC) and Citrobacter rodentium sense and utilize galacturonic acid (GalA), an isomer of GlcA, to outcompete the microbiota promoting gut colonization. However, the role of GlcA in pathogen colonization has not been explored. Here, we show that treatment of mice with a microbial ß-glucuronidase inhibitor (GUSi) decreased C. rodentium's colonization of the GI tract, without modulating bacterial virulence or host inflammation. Metagenomic studies indicated that GUSi did not change the composition of the intestinal microbiota in these animals. GlcA confers an advantage for pathogen expansion through its utilization as a carbon source. Congruently mutants unable to catabolize GlcA depict lower GI colonization compared to wild type and are not sensitive to GUSi. Germfree mice colonized with a commensal E. coli deficient for ß-glucuronidase production led to a decrease of C. rodentium tissue colonization, compared to animals monocolonized with an E. coli proficient for production of this enzyme. GlcA is not sensed as a signal and doesn't activate virulence expression but is used as a metabolite. Because pathogens can use GlcA to promote their colonization, inhibitors of microbial ß-glucuronidases could be a unique therapeutic against enteric infections without disturbing the host or microbiota physiology.


Assuntos
Infecções por Escherichia coli , Microbiota , Animais , Camundongos , Escherichia coli/genética , Ácido Glucurônico , Infecções por Escherichia coli/tratamento farmacológico , Infecções por Escherichia coli/microbiologia , Virulência/fisiologia
12.
World J Microbiol Biotechnol ; 40(3): 94, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38349469

RESUMO

D-glucuronic acid is a kind of glucose derivative, which has excellent properties such as anti-oxidation, treatment of liver disease and hyperlipidemia, and has been widely used in medicine, cosmetics, food and other fields. The traditional production methods of D-glucuronic acid mainly include natural extraction and chemical synthesis, which can no longer meet the growing market demand. The production of D-glucuronic acid by biocatalysis has become a promising alternative method because of its high efficiency and environmental friendliness. This review describes different production methods of D-glucuronic acid, including single enzyme catalysis, multi-enzyme cascade, whole cell catalysis and co-culture, as well as the intervention of some special catalysts. In addition, some feasible enzyme engineering strategies are provided, including the application of enzyme immobilized scaffold, enzyme mutation and high-throughput screening, which provide good ideas for the research of D-glucuronic acid biocatalysis.


Assuntos
Engenharia , Biocatálise , Catálise , Técnicas de Cocultura , Ácido Glucurônico
13.
Environ Res ; 250: 118440, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38360164

RESUMO

Ferrihydrite is an effective adsorbent of chromate and arsenate. In order to gain insight into the application of ferrihydrite in water treatment, macroporous alginate/ferrihydrite beads, synthesized using two different methods (internal and encapsulation processes), were used in this work. The properties of the ferrihydrite were assessed using various techniques, including X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Brunauer-Emmett-Teller (BET) theory, and zetametry. The results showed that the specific surface area of the ferrihydrite was 242 m2/g, and the PZC was pH8. The kinetic and isotherm adsorption properties of the ferrihydrite were evaluated in this study. The results indicate that the pseudo second-order and Freundlich models accurately describe the kinetic and isotherm adsorption properties of chromates and arsenates. For chromate removal, ferrihydrite exhibited a relatively high adsorption capacity (40.7 mgCr/g) compared to other adsorbents. However, the arsenate adsorption capacity of MFHB-SI (140.8 mgAs/g) was shown to be the most optimal. The internal synthesis process was suitable for arsenate retention due to the resulting arsenate precipitation. The competitive adsorption analyses indicated that the presence of chromate does not limit the adsorption of arsenate. However, the presence of arsenate almost completely inhibits the adsorption of chromate when the arsenate concentration is above 50 mg/L, due to the precipitation reaction of arsenate.


Assuntos
Alginatos , Arseniatos , Cromatos , Compostos Férricos , Poluentes Químicos da Água , Arseniatos/química , Adsorção , Cromatos/química , Compostos Férricos/química , Alginatos/química , Poluentes Químicos da Água/química , Ácido Glucurônico/química , Cinética , Ácidos Hexurônicos/química , Purificação da Água/métodos
14.
J Biol Chem ; 300(3): 105774, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38382672

RESUMO

Gum arabic (GA) is widely used as an emulsion stabilizer and edible coating and consists of a complex carbohydrate moiety with a rhamnosyl-glucuronate group capping the non-reducing ends. Enzymes that can specifically cleave the glycosidic chains of GA and modify their properties are valuable for structural analysis and industrial application. Cryogenic X-ray crystal structure of GA-specific L-rhamnose-α-1,4-D-glucuronate lyase from Fusarium oxysporum (FoRham1), belonging to the polysaccharide lyase (PL) family 42, has been previously reported. To determine the specific reaction mechanism based on its hydrogen-containing enzyme structure, we performed joint X-ray/neutron crystallography of FoRham1. Large crystals were grown in the presence of L-rhamnose (a reaction product), and neutron and X-ray diffraction datasets were collected at room temperature at 1.80 and 1.25 Å resolutions, respectively. The active site contained L-rhamnose and acetate, the latter being a partial analog of glucuronate. Incomplete H/D exchange between Arg166 and acetate suggested that a strong salt-bridge interaction was maintained. Doubly deuterated His105 and deuterated Tyr150 supported the interaction between Arg166 and the acetate. The unique hydrogen-rich environment functions as a charge neutralizer for glucuronate and stabilizes the oxyanion intermediate. The NE2 atom of His85 was deprotonated and formed a hydrogen bond with the deuterated O1 hydroxy of L-rhamnose, indicating the function of His85 as the base/acid catalyst for bond cleavage via ß-elimination. Asp83 functions as a pivot between the two catalytic histidine residues by bridging them. This His-His-Asp structural motif is conserved in the PL 24, 25, and 42 families.


Assuntos
Fusarium , Polissacarídeo-Liases , Humanos , Acetatos , Cristalografia por Raios X , Ácido Glucurônico/química , Hidrogênio , Liases , Polissacarídeo-Liases/química , Ramnose/química , Fusarium/enzimologia
15.
Adv Healthc Mater ; 13(12): e2303546, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38224572

RESUMO

This work reports localized in vivo gene transfer by biodegradation of the adeno-associated virus-encapsulating alginate microspheres (AAV-AMs) loaded in collagen gel carriers. AAV-AMs are centrifugally synthesized by ejecting a mixed pre-gel solution of alginate and AAV to CaCl2 solution to form an ionically cross-linked hydrogel microsphere immediately. The AAV-AMs are able to preserve the AAV without diffusing out even after spreading them on the cells, and the AAV is released and transfected by the degradation of the alginate microsphere. In addition, AAV-AMs can be stored by cryopreservation until use. By implanting this highly convenient AAV-encapsulated hydrogel, AAV-AMs can be loaded into collagen gel carriers to fix the position of the implanted AAV-AMs and achieve localized gene transfer in vivo. In vivo experiments show that the AAV-AMs loaded in collagen gel carriers are demonstrated to release the encapsulated AAV for gene transfer in the buttocks muscles of mice. While conventional injections caused gene transfer to the entire surrounding tissue, the biodegradation of AAV-AMs shows that gene transfer is achieved locally to the muscles. This means that the proposed AAV-loaded system is shown to be a superior method for selective gene transfer.


Assuntos
Alginatos , Colágeno , Dependovirus , Microesferas , Dependovirus/genética , Alginatos/química , Animais , Colágeno/química , Camundongos , Técnicas de Transferência de Genes , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Humanos , Hidrogéis/química , Géis/química
16.
Org Biomol Chem ; 22(7): 1395-1399, 2024 02 14.
Artigo em Inglês | MEDLINE | ID: mdl-38291974

RESUMO

Herein we utilise automated glycan assembly to complete solid-phase synthesis of defined heparan sulfate oligosaccharides, employing challenging D-glucuronate disaccharide donors. Using an orthogonally protected D-GlcN-α-D-GlcA donor, milligram-scale synthesis of a heparan sulfate tetrasaccharide is completed in 18% yield over five steps. Furthermore, orthogonal protecting groups enabled regiospecific on-resin 6-O-sulfation. This methodology provides an important benchmark for the rapid assembly of biologically relevant heparan sulfate sequences.


Assuntos
Heparitina Sulfato , Oligossacarídeos , Dissacarídeos , Glucuronatos , Ácido Glucurônico
17.
J Nat Prod ; 87(2): 228-237, 2024 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-38266493

RESUMO

As a model liverwort, Marchantia polymorpha contains various flavone glucuronides with cardiovascular-promoting effects and anti-inflammatory properties. However, the related glucuronosyltransferases have not yet been reported. In this study, two bifunctional UDP-glucuronic acid/UDP-glucose:flavonoid glucuronosyltransferases/glucosyltransferases, MpUGT742A1 and MpUGT736B1, were identified from M. polymorpha. Extensive enzymatic assays found that MpUGT742A1 and MpUGT736B1 exhibited efficient glucuronidation activity for flavones, flavonols, and flavanones and showed promiscuous regioselectivity at positions 3, 6, 7, 3', and 4'. These enzymes catalyzed the production of a variety of flavonoid glucuronides with medicinal value, including apigenin-7-O-glucuronide and scutellarein-7-O-glucuronide. With the use of MpUGT736B1, apigenin-4'-O-glucuronide and apigenin-7,4'-di-O-glucuronide were prepared by scaled-up enzymatic catalysis and structurally identified by NMR spectroscopy. MpUGT742A1 also displayed glucosyltransferase activity on the 7-OH position of the flavanones using UDP-glucose as the sugar donor. Furthermore, we constructed four recombinant strains by combining the pathway for increasing the UDP-glucuronic acid supply with the two novel UGTs MpUGT742A1 and MpUGT736B1. When apigenin was used as a substrate, the extracellular apigenin-4'-O-glucuronide and apigenin-7,4'-di-O-glucuronide production obtained from the Escherichia coli strain BB2 reached 598 and 81 mg/L, respectively. Our study provides new candidate genes and strategies for the biosynthesis of flavonoid glucuronides.


Assuntos
Flavanonas , Marchantia , Flavonoides/química , Apigenina , Glucuronídeos/metabolismo , Marchantia/metabolismo , Glucuronosiltransferase/química , Glucuronosiltransferase/metabolismo , Escherichia coli/metabolismo , Glucose , Ácido Glucurônico , Difosfato de Uridina
18.
Bioconjug Chem ; 35(1): 34-42, 2024 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-37964742

RESUMO

Multivalent glycodendrimers are valuable tools for studying carbohydrate-protein interactions, and their scaffolds represent important components to increase specificity and affinity. Previous work by our group described the preparation of a tetravalent glucuronic acid rigid dendron that binds with good affinity to the dengue virus envelope protein (KD = 22 µM). Herein, the chemical synthesis and binding analysis of three new sets of rigid, semirigid, and flexible glucuronic acid-based dendrimers bearing different levels of multivalency and their interactions with the dengue virus envelope protein are described. The different oligoalkynyl scaffolds were coupled to glucuronic acid azides by a copper-catalyzed azide-alkyne cycloaddition reaction through optimized synthetic strategies to afford the desired glycodendrimers with good yields. Surface plasmon resonance studies have demonstrated that glycodendrimers 12b and 12c, with flexible scaffolds, give the best binding interactions with the dengue virus envelope protein (12b: KD = 0.487 µM and 12c: KD = 0.624 µM). Their binding constant values were 45 and 35 times higher than the one obtained in previous studies with a rigid tetravalent glucuronic acid dendron (KD = 22 µM), respectively. Molecular modeling studies were carried out in order to understand the difference in behavior observed for 12b and 12c. This work reports an efficient glycodendrimer chemical synthesis process that provides an appropriate scaffold that offers an easy and versatile strategy to find new active compounds against the dengue virus.


Assuntos
Dendrímeros , Vírus da Dengue , Dengue , Humanos , Vírus da Dengue/química , Ácido Glucurônico , Proteínas do Envelope Viral/química , Dendrímeros/química
19.
J Sci Food Agric ; 104(4): 2458-2466, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-37975168

RESUMO

BACKGROUND: Calcium alginate gels are widely used to encapsulate active compounds. Some characteristic parameters of these gels are necessary to describe the release of active compounds through mechanistic mathematical models. In this work, transport and kinetics properties of calcium alginate gels were determined through simple experimental techniques. RESULTS: The weight-average molecular weight ( M ¯ w = 192 × 103 Da) and the fraction of residues of α-l-guluronic acid ( F G = 0.356) of sodium alginate were determined by capillary viscometry and 1 H-nuclear magnetic resonance at 25 °C, respectively. Considering the half egg-box model, both values were used to estimate the molecular weight of calcium alginate as M g = 2.02 × 105 Da. An effective diffusion coefficient of water ( D eff , w = 2.256 × 10-9 m2 s-1 ) in calcium alginate was determined using a diffusion cell at 37 °C. Finally, a kinetics constant of depolymerization ( k m = 9.72 × 10-9 m3 mol-1 s-1 ) of calcium alginate was obtained considering dissolution of calcium to a medium under intestinal conditions. CONCLUSION: The experimental techniques used are simple and easily reproducible. The obtained values may be useful in the design, production, and optimization of the alginate-based delivery systems that require specific release kinetics of the encapsulated active compounds. © 2023 Society of Chemical Industry.


Assuntos
Alginatos , Imageamento por Ressonância Magnética , Alginatos/química , Géis/química , Espectroscopia de Ressonância Magnética , Modelos Teóricos , Cálcio/química , Ácidos Hexurônicos/química , Ácido Glucurônico/química
20.
Langmuir ; 40(3): 1950-1960, 2024 01 23.
Artigo em Inglês | MEDLINE | ID: mdl-37991242

RESUMO

Core-shell hydrogel microcapsules have sparked great interest due to their unique characteristics and prospective applications in the medical, pharmaceutical, and cosmetic fields. However, complex synthetic procedures and expensive costs have limited their practical application. Herein, we designed and prepared several multichannel and multijunctional droplet microfluidic devices based on soft lithography for the effective synthesis of core-shell hydrogel microcapsules for different purposes. Additionally, two different cross-linking processes (ultraviolet (UV) exposure and interfacial polymerization) were used to synthesize different types of core-shell structured hydrogel microcapsules. Hydrogel microcapsules with gelatin methacryloyl (GelMA) as the core and polyacrylamide (PAM) as the thin shell were synthesized using UV cross-linking. Using an interfacial polymerization process, another core-shell structured microcapsule with GelMA as the core and Ca2+ cross-linked alginate with polyethylenimine (PEI) as the shell was constructed, and the core diameter and total droplet diameter were flexibly controlled by carving. Noteworthy, these hydrogel microcapsules exhibit stimuli-responsiveness and controlled release ability. Overall, a novel technique was developed to successfully synthesize various hydrogel microcapsules with core-shell microstructures. The hydrogel microcapsules possess a multilayered structure that facilitates the coassembly of cells and drugs, as well as the layered assembly of multiple drugs, to develop synergistic therapeutic regimens. These adaptable and controllable hydrogel microdroplets shall held great promise for multicell or multidrug administration as well as for high-throughput drug screening.


Assuntos
Alginatos , Hidrogéis , Hidrogéis/química , Cápsulas/química , Alginatos/química , Ácido Glucurônico/química , Ácidos Hexurônicos/química
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