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1.
Carbohydr Polym ; 338: 122204, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38763712

RESUMO

This study presents the development and characterization of a novel double-network self-healing hydrogel based on N-carboxyethyl chitosan (CEC) and oxidized dextran (OD) with the incorporation of crosslinked collagen (CEC-OD/COL-GP) to enhance its biological and physicochemical properties. The hydrogel formed via dynamic imine bond formation exhibited efficient self-healing within 30 min, and a compressive modulus recovery of 92 % within 2 h. In addition to its self-healing ability, CEC-OD/COL-GP possesses unique physicochemical characteristics including transparency, injectability, and adhesiveness to various substrates and tissues. Cell encapsulation studies confirmed the biocompatibility and suitability of the hydrogel as a cell-culture scaffold, with the presence of a collagen network that enhances cell adhesion, spreading, long-term cell viability, and proliferation. Leveraging their unique properties, we engineered assemblies of self-healing hydrogel modules for controlled spatiotemporal drug delivery and constructed co-culture models that simulate angiogenesis in tumor microenvironments. Overall, the CEC-OD/COL-GP hydrogel is a versatile and promising material for biomedical applications, offering a bottom-up approach for constructing complex structures with self-healing capabilities, controlled drug release, and support for diverse cell types in 3D environments. This hydrogel platform has considerable potential for advancements in tissue engineering and therapeutic interventions.


Assuntos
Adesão Celular , Quitosana , Dextranos , Hidrogéis , Hidrogéis/química , Hidrogéis/farmacologia , Quitosana/química , Dextranos/química , Humanos , Adesão Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Colágeno/química , Animais , Liberação Controlada de Fármacos , Proliferação de Células/efeitos dos fármacos , Encapsulamento de Células/métodos , Materiais Biomiméticos/química , Materiais Biomiméticos/farmacologia , Camundongos , Biomimética/métodos , Materiais Biocompatíveis/química , Materiais Biocompatíveis/farmacologia , Alicerces Teciduais/química
2.
Nutrients ; 16(9)2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38732595

RESUMO

While ketogenic diets (KDs) may have potential as adjunct treatments for gastrointestinal diseases, there is little knowledge on how the fat source of these diets impacts intestinal health. The objective of this study was to investigate how the source of dietary fat of KD influences experimental colitis. We fed nine-week-old male C57BL/6J mice (n = 36) with a low-fat control diet or KD high either in saturated fatty acids (SFA-KD) or polyunsaturated linoleic acid (LA-KD) for four weeks and then induced colitis with dextran sodium sulfate (DSS). To compare the diets, we analyzed macroscopic and histological changes in the colon, intestinal permeability to fluorescein isothiocyanate-dextran (FITC-dextran), and the colonic expression of tight junction proteins and inflammatory markers. While the effects were more pronounced with LA-KD, both KDs markedly alleviated DSS-induced histological lesions. LA-KD prevented inflammation-related weight loss and the shortening of the colon, as well as preserved Il1b and Tnf expression at a healthy level. Despite no significant between-group differences in permeability to FITC-dextran, LA-KD mitigated changes in tight junction protein expression. Thus, KDs may have preventive potential against intestinal inflammation, with the level of the effect being dependent on the dietary fat source.


Assuntos
Colite , Colo , Sulfato de Dextrana , Dieta Cetogênica , Gorduras na Dieta , Modelos Animais de Doenças , Fluoresceína-5-Isotiocianato/análogos & derivados , Camundongos Endogâmicos C57BL , Animais , Colite/induzido quimicamente , Colite/dietoterapia , Masculino , Camundongos , Gorduras na Dieta/efeitos adversos , Colo/patologia , Colo/metabolismo , Permeabilidade , Proteínas de Junções Íntimas/metabolismo , Interleucina-1beta/metabolismo , Mucosa Intestinal/patologia , Mucosa Intestinal/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Ácidos Graxos , Dextranos
3.
Biomacromolecules ; 25(5): 3122-3130, 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38696355

RESUMO

Synthesis of polysaccharide-b-polypeptide block copolymers represents an attractive goal because of their promising potential in delivery applications. Inspired by recent breakthroughs in N-carboxyanhydride (NCA) ring-opening polymerization (ROP), we present an efficient approach for preparation of a dextran-based macroinitiator and the subsequent synthesis of dextran-b-polypeptides via NCA ROP. This is an original approach to creating and employing a native polysaccharide macroinitiator for block copolymer synthesis. In this strategy, regioselective (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) oxidation of the sole primary alcohol located at the C-6 position of the monosaccharide at the nonreducing end of linear dextran results in a carboxylic acid. This motif is then transformed into a tetraalkylammonium carboxylate, thereby generating the dextran macroinitiator. This macroinitiator initiates a wide range of NCA monomers and produces dextran-b-polypeptides with a degree of polymerization (DP) of the polypeptide up to 70 in a controlled manner (D < 1.3). This strategy offers several distinct advantages, including preservation of the original dextran backbone structure, relatively rapid polymerization, and moisture tolerance. The dextran-b-polypeptides exhibit interesting self-assembly behavior. Their nanostructures have been investigated by dynamic light scattering (DLS) and transmission electron microscopy (TEM), and adjustment of the structure of block copolymers allows self-assembly of spherical micelles and worm-like micelles with varied diameters and aspect ratios, revealing a range of diameters from 60 to 160 nm. Moreover, these nanostructures exhibit diverse morphologies, including spherical micelles and worm-like micelles, enabling delivery applications.


Assuntos
Dextranos , Peptídeos , Polimerização , Dextranos/química , Peptídeos/química , Peptídeos/síntese química , Polímeros/química , Polímeros/síntese química , Óxidos N-Cíclicos/química , Anidridos/química , Polissacarídeos/química , Micelas
4.
Transl Vis Sci Technol ; 13(5): 5, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38713474

RESUMO

Purpose: The blood-retinal barrier (BRB) restricts the delivery of intravenous therapeutics to the retina, necessitating innovative approaches for treating retinal disorders. This study sought to explore the potential of focused ultrasound (FUS) to non-invasively deliver intravenously administered gold nanoparticles (AuNPs) across the BRB. FUS-BRB modulation can offer a novel method for targeted retinal therapy. Methods: AuNPs of different sizes and shapes were characterized, and FUS parameters were optimized to permeate the BRB without causing retinal damage in a rodent model. The delivery of 70-kDa dextran and AuNPs to the retinal ganglion cell (RGC) layer was visualized using confocal and two-photon microscopy, respectively. Histological and statistical analyses were conducted to assess the effectiveness and safety of the procedure. Results: FUS-BRB modulation resulted in the delivery of dextran and AuNPs to the RGC and inner nuclear layer. Smaller AuNPs reached the retinal layers to a greater extent than larger ones. The delivery of dextran and AuNPs across the BRB with FUS was achieved without significant retinal damage. Conclusions: This investigation provides the first evidence, to our knowledge, of FUS-mediated AuNP delivery across the BRB, establishing a foundation for a targeted and non-invasive approach to retinal treatment. The results contribute to developing promising non-invasive therapeutic strategies in ophthalmology to treat retinal diseases. Translational Relevance: Modifying the BRB with ultrasound offers a targeted and non-invasive delivery strategy of intravenous therapeutics to the retina.


Assuntos
Barreira Hematorretiniana , Ouro , Nanopartículas Metálicas , Células Ganglionares da Retina , Animais , Ouro/química , Ouro/administração & dosagem , Células Ganglionares da Retina/citologia , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Dextranos/administração & dosagem , Dextranos/química , Sistemas de Liberação de Medicamentos/métodos , Ratos , Microscopia Confocal/métodos , Masculino
5.
Carbohydr Polym ; 337: 122147, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38710554

RESUMO

Treatment of infected wound by simultaneously eliminating bacteria and inducing angiogenesis to promote wound tissue regeneration remains a clinical challenge. Dynamic and reversable hydrogels can adapt to irregular wound beds, which have raised great attention as wound dressings. Herein, a sprayable chitosan-based hydrogel (HPC/CCS/ODex-IGF1) was developed using hydroxypropyl chitosan (HPC), caffeic acid functionalized chitosan (CCS), oxidized dextran (ODex) to crosslink through the dynamic imine bond, which was pH-responsive to the acidic microenvironment and could controllably release insulin growth factor-1 (IGF1). The HPC/CCS/ODex-IGF1 hydrogels not only showed self-healing, self-adaptable and sprayable properties, but also exhibited excellent antibacterial ability, antioxidant property, low-cytotoxicity and angiogenetic activity. In vivo experiments demonstrated that hydrogels promoted tissue regeneration and healing of bacteria-infected wound with a rate of approximately 98.4 % on day 11 by eliminating bacteria, reducing inflammatory and facilitating angiogenesis, demonstrating its great potential for wound dressing.


Assuntos
Antibacterianos , Quitosana , Hidrogéis , Neovascularização Fisiológica , Cicatrização , Quitosana/química , Quitosana/farmacologia , Hidrogéis/química , Hidrogéis/farmacologia , Cicatrização/efeitos dos fármacos , Animais , Antibacterianos/farmacologia , Antibacterianos/química , Camundongos , Neovascularização Fisiológica/efeitos dos fármacos , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/uso terapêutico , Humanos , Masculino , Fator de Crescimento Insulin-Like I , Staphylococcus aureus/efeitos dos fármacos , Bandagens , Infecção dos Ferimentos/tratamento farmacológico , Infecção dos Ferimentos/microbiologia , Dextranos/química , Dextranos/farmacologia , Angiogênese
6.
Fr J Urol ; 34(2): 102585, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38717460

RESUMO

INTRODUCTION: The aim was to compare the efficacy of polyacrylate polyalcohol copolymer (PPC) injections and dextranomer/hyaluronic acid (Dx/Ha) injections for the endoscopic treatment of vesicoureteral reflux in children. MATERIAL: This retrospective cohort study included 189 young patients who had endoscopic treatment for vesicoureteral reflux from January 2012 to December 2019 in our center. Among them, 101 had PCC injections and 88 had Dx/Ha injections. Indications for treatment were vesicoureteral reflux with breakthrough urinary tract infection or vesicoureteral reflux with renal scarring on dimercaptosuccinic acid (DMSA) renal scan. Endoscopic injection was performed under the ureteral meatus. Early complications, recurrence of febrile urinary tract infection and vesicoureteral reflux after endoscopic injection, ureteral obstruction and reintervention were evaluated and compared between groups. RESULTS: Endoscopic treatment was successful in 90.1% of patients who had PPC injection and in 82% of patients who had Dx/Ha injection. Four patients presented a chronic ureteral obstruction after PPC injection, one with a complete loss of function of the dilated kidney. One patient in the Dx/Ha group presented a postoperative ureteral dilatation after 2 injections. CONCLUSION: Despite a similar success rate after PPC and Dx/Ha injections for endoscopic treatment of VUR, there may be a greater risk of postoperative ureteral obstruction after PPC injections. The benefit of using PPC to prevent febrile UTI and renal scarring in children with low-grade VUR does not seem to outweigh the risk of chronic ureteral obstruction.


Assuntos
Dextranos , Ácido Hialurônico , Obstrução Ureteral , Refluxo Vesicoureteral , Humanos , Refluxo Vesicoureteral/terapia , Estudos Retrospectivos , Ácido Hialurônico/administração & dosagem , Ácido Hialurônico/uso terapêutico , Ácido Hialurônico/efeitos adversos , Feminino , Masculino , Dextranos/uso terapêutico , Dextranos/administração & dosagem , Dextranos/efeitos adversos , Pré-Escolar , Resultado do Tratamento , Lactente , Resinas Acrílicas/uso terapêutico , Resinas Acrílicas/administração & dosagem , Criança , Injeções , Estudos de Coortes , Ureteroscopia/efeitos adversos
7.
J Colloid Interface Sci ; 666: 603-614, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-38613982

RESUMO

There has been an increasing demand for simultaneous detection of multiple analytes in one sample. Microbead-based platforms have been developed for multiplexed assays. However, most of the microbeads are made of non-biodegradable synthetic polymers, leading to environmental and human health concerns. In this study, we developed an environmentally friendly dextran microbeads as a new type of multi-analyte assay platform. Biodegradable dextran was utilized as the primary material. Highly uniform magnetic dextran microspheres were successfully synthesized using the Shirasu porous glass (SPG) membrane emulsification technique. To enhance the amount of surface functional groups for ligand conjugation, we coated the dextran microbeads with a layer of dendrimers via a simple electrostatic adsorption process. Subsequently, a unique and efficient click chemistry coupling technique was developed for the fluorescence encoding of the microspheres, enabling multiplexed detection. The dextran microbeads were tested for 3-plex cytokine analysis, and exhibited excellent biocompatibility, stable coding signals, low background noise and high sensitivity.


Assuntos
Dextranos , Microesferas , Dextranos/química , Tamanho da Partícula , Propriedades de Superfície , Humanos , Citocinas/análise , Química Click , Porosidade , Camundongos , Animais , Química Verde
8.
PLoS One ; 19(4): e0297738, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38626108

RESUMO

The nucleus preserves the genomic DNA of eukaryotic organisms and maintains the integrity of the cell by regulating the transport of molecules across the nuclear membrane. It is hitherto assumed that small molecules having a size below the passive permeability limit are allowed to diffuse freely to the nucleus while the transport of larger molecules is regulated via an active mechanism involving energy. Here we report on the kinetics of nuclear import and export of dextran molecules having a size below the passive permeability limit. The studies carried out using time-lapse confocal fluorescence microscopy show a clear deviation from the passive diffusion model. In particular, it is observed that the steady-state concentration of dextran molecules inside the nucleus is consistently less than the concentration outside, in contradiction to the predictions of the passive diffusion model. Detailed analysis and modeling of the transport show that the nuclear export rates significantly differ from the import rates, and the difference in rates is dependent on the size of the molecules. The nuclear export rates are further confirmed by an independent experimental study where we observe the diffusion of dextran molecules from the nucleus directly. Our experiments and transport model would suggest that the nucleus actively rejects exogenous macromolecules even below the passive permeability limit. This result can have a significant impact on biomedical research, especially in areas related to targeted drug delivery and gene therapy.


Assuntos
Núcleo Celular , Membrana Nuclear , Membrana Nuclear/metabolismo , Núcleo Celular/metabolismo , Dextranos/metabolismo , Transporte Ativo do Núcleo Celular , Difusão
9.
PLoS One ; 19(4): e0301432, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38626169

RESUMO

Diffusion within extracellular matrix is essential to deliver nutrients and larger metabolites to the avascular region of the meniscus. It is well known that both structure and composition of the meniscus vary across its regions; therefore, it is crucial to fully understand how the heterogenous meniscal architecture affects its diffusive properties. The objective of this study was to investigate the effect of meniscal region (core tissue, femoral, and tibial surface layers) and molecular weight on the diffusivity of several molecules in porcine meniscus. Tissue samples were harvested from the central area of porcine lateral menisci. Diffusivity of fluorescein (MW 332 Da) and three fluorescence-labeled dextrans (MW 3k, 40k, and 150k Da) was measured via fluorescence recovery after photobleaching. Diffusivity was affected by molecular size, decreasing as the Stokes' radius of the solute increased. There was no significant effect of meniscal region on diffusivity for fluorescein, 3k and 40k dextrans (p>0.05). However, region did significantly affect the diffusivity of 150k Dextran, with that in the tibial surface layer being larger than in the core region (p = 0.001). Our findings contribute novel knowledge concerning the transport properties of the meniscus fibrocartilage. This data can be used to advance the understanding of tissue pathophysiology and explore effective approaches for tissue restoration.


Assuntos
Dextranos , Menisco , Animais , Suínos , Dextranos/metabolismo , Menisco/metabolismo , Meniscos Tibiais/fisiologia , Fibrocartilagem/metabolismo , Fluoresceínas/metabolismo
10.
Compr Rev Food Sci Food Saf ; 23(3): e13353, 2024 05.
Artigo em Inglês | MEDLINE | ID: mdl-38660747

RESUMO

Deterioration of bread quality, characterized by the staling of bread crumb, the softening of bread crust and the loss of aroma, has caused a huge food waste and economic loss, which is a bottleneck restriction to the development of the breadmaking industry. Various bread improvers have been widely used to alleviate the issue. However, it is noteworthy that the sourdough technology has emerged as a pivotal factor in this regard. In sourdough, the metabolic breakdown of carbohydrates, proteins, and lipids leads to the production of exopolysaccharides, organic acids, aroma compounds, or prebiotics, which contributes to the preeminent ability of sourdough to enhance bread attributes. Moreover, sourdough exhibits a "green-label" feature, which satisfies the consumers' increasing demand for additive-free food products. In the past two decades, there has been a significant focus on sourdough with in situ produced dextran due to its exceptional performance. In this review, the behaviors of bread crucial compositions (i.e., starch and gluten) during dough mixing, proofing, baking and bread storing, as well as alterations induced by the acidic environment and the presence of dextran are systemically summarized. From the viewpoint of starch and gluten, results obtained confirm the synergistic amelioration on bread quality by the coadministration of acidity and dextran, and also highlight the central role of acidification. This review contributes to establishing a theoretical foundation for more effectively enhancing the quality of wheat breads through the application of in situ produced dextran.


Assuntos
Pão , Dextranos , Glutens , Amido , Triticum , Pão/análise , Pão/normas , Amido/química , Glutens/química , Dextranos/química , Triticum/química , Fermentação , Manipulação de Alimentos/métodos , Qualidade dos Alimentos
11.
Methods Mol Biol ; 2788: 49-66, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38656508

RESUMO

Calibrated size exclusion chromatography (SEC) is a useful tool for the analysis of molecular dimensions of polysaccharides. The calibration takes place with a set of narrow distributed dextran standards and peak position technique. Adapted columns systems and dissolving processes enable for the adequate separation of carbohydrate polymers. Plant-extracted fructan (a homopolymer with low molar mass and excellent water solubility) and mucilage (differently structured, high molar mass heteropolysaccarides that include existing supramolecular structures, and require a long dissolving time) are presented as examples of the versatility of this technique. Since narrow standards similar to the samples (chemically and structurally) are often unavailable, it must be noted that the obtained molar mass values and distributions by this method are only apparent (relative) values, expressed as dextran equivalents.


Assuntos
Cromatografia em Gel , Peso Molecular , Polissacarídeos , Cromatografia em Gel/métodos , Polissacarídeos/química , Polissacarídeos/análise , Dextranos/química , Frutanos/química , Frutanos/análise , Calibragem
12.
Molecules ; 29(8)2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38675647

RESUMO

This study aimed to develop multifunctional nanoplatforms for both cancer imaging and therapy using superparamagnetic iron oxide nanoparticles (SPIONs). Two distinct synthetic methods, reduction-precipitation (MR/P) and co-precipitation at controlled pH (MpH), were explored, including the assessment of the coating's influence, namely dextran and gold, on their magnetic properties. These SPIONs were further functionalized with gadolinium to act as dual T1/T2 contrast agents for magnetic resonance imaging (MRI). Parameters such as size, stability, morphology, and magnetic behavior were evaluated by a detailed characterization analysis. To assess their efficacy in imaging and therapy, relaxivity and hyperthermia experiments were performed, respectively. The results revealed that both synthetic methods lead to SPIONs with similar average size, 9 nm. Mössbauer spectroscopy indicated that samples obtained from MR/P consist of approximately 11-13% of Fe present in magnetite, while samples obtained from MpH have higher contents of 33-45%. Despite coating and functionalization, all samples exhibited superparamagnetic behavior at room temperature. Hyperthermia experiments showed increased SAR values with higher magnetic field intensity and frequency. Moreover, the relaxivity studies suggested potential dual T1/T2 contrast agent capabilities for the coated SPpH-Dx-Au-Gd sample, thus demonstrating its potential in cancer diagnosis.


Assuntos
Meios de Contraste , Nanopartículas Magnéticas de Óxido de Ferro , Imageamento por Ressonância Magnética , Nanopartículas de Magnetita , Nanomedicina Teranóstica , Nanopartículas Magnéticas de Óxido de Ferro/química , Imageamento por Ressonância Magnética/métodos , Meios de Contraste/química , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/uso terapêutico , Humanos , Ouro/química , Dextranos/química , Gadolínio/química , Propriedades de Superfície , Hipertermia Induzida/métodos , Tamanho da Partícula
13.
Food Chem ; 449: 139310, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38608612

RESUMO

This study investigated the effects of the conjugate reaction sequences of whey protein concentrate (WPC), epigallocatechin gallate (EGCG) and dextran (DEX) on the structure and emulsion properties of conjugates and the bioaccessibility of astaxanthin (AST). Two types of ternary covalent complexes were synthesised using WPC, EGCG and DEX, which were regarded as emulsifiers of AST nanoemulsions. Results indicated that the WPC-DEX-EGCG conjugate (referred to as 'con') exhibits a darker SDS-PAGE dispersion band and higher contents of α-helix (6%), ß-angle (24%) and random coil (32%), resulting in a greater degree of unfolding structure and fluorescence quenching. These findings suggested WPC-DEX-EGCG con had the potential to exhibit better emulsification properties than WPC-EGCG-DEX con. AST encapsulation efficiency (76.22%) and bioavailability (31.89%) also demonstrated the superior performance of the WPC-DEX-EGCG con emulsifier in nanoemulsion delivery systems. These findings indicate that altering reaction sequences changes protein conformation, enhancing the emulsification properties and bioavailability of AST.


Assuntos
Disponibilidade Biológica , Catequina/análogos & derivados , Emulsificantes , Emulsões , Proteínas do Soro do Leite , Xantofilas , Xantofilas/química , Emulsões/química , Emulsificantes/química , Proteínas do Soro do Leite/química , Animais , Catequina/química , Dextranos/química , Masculino , Ratos , Ratos Sprague-Dawley
14.
Langmuir ; 40(17): 9082-9096, 2024 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-38619979

RESUMO

Great efforts have been devoted to the development of novel and multifunctional wound dressing materials to meet the different needs of wound healing. Herein, we covalently grafted quaternary ammonium groups (QAGs) containing 12-carbon straight-chain alkanes to the dextran polymer skeleton. We then oxidized the resulting product into oxidized quaternized dextran (OQD). The obtained OQD polymer is rich in antibacterial QAGs and aldehyde groups. It can react with glycol chitosan (GC) via the Schiff-base reaction to form a multifunctional GC@OQD hydrogel with good self-healing behavior, hemostasis, injectability, inherent superior antibacterial activity, biocompatibility, and excellent promotion of healing of methicillin-resistant Staphylococcus aureus (MRSA)-infected wounds. The biosafe and nontoxic GC@OQD hydrogel with a three-dimensional porous network structure possesses an excellent swelling rate and water retention capacity. It can be used for hemostasis and treating irregular wounds. The designed GC@OQD hydrogel with inherent antibacterial activity possesses good antibacterial efficacy on both S. aureus (Gram-positive bacteria) and Escherichia coli (Gram-negative bacteria), as well as MRSA bacteria, with antibacterial activity greater than 99%. It can be used for the treatment of wounds infected by MRSA and significantly promotes the healing of wounds. Thus, the multifunctional antibacterial GC@OQD hydrogel has the potential to be applied in clinical practice as a wound dressing.


Assuntos
Antibacterianos , Quitosana , Escherichia coli , Hidrogéis , Staphylococcus aureus Resistente à Meticilina , Cicatrização , Hidrogéis/química , Hidrogéis/farmacologia , Cicatrização/efeitos dos fármacos , Antibacterianos/farmacologia , Antibacterianos/química , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Animais , Quitosana/química , Quitosana/farmacologia , Dextranos/química , Dextranos/farmacologia , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos , Camundongos , Polissacarídeos/química , Polissacarídeos/farmacologia
15.
Int J Biol Macromol ; 267(Pt 2): 131520, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38615859

RESUMO

The adverse microenvironment, including neuroinflammation, hinders the recovery of spinal cord injury (SCI). Regulating microglial polarization to alleviate neuroinflammation at the injury site is an effective strategy for SCI recovery. MG53 protein exerts obvious repair ability on multiple tissues damage, but with short half-life. In this study, we composited an innovative MG53/GMs/HA-Dex neural scaffold using gelatin microspheres (GMs), hyaluronic acid (HA), and dextran (Dex) loaded with MG53 protein. This novel neural scaffold could respond to MMP-2/9 protein and stably release MG53 protein with good physicochemical properties and biocompatibility. In addition, it significantly improved the motor function of SCI mice, suppressed M1 polarization of microglia and neuroinflammation, and promoted neurogenesis and axon regeneration. Further mechanistic experiments demonstrated that MG53/GMs/HA-Dex hydrogel inhibited the JAK2/STAT3 signaling pathway. Thus, this MG53/GMs/HA-Dex neural scaffold promotes the functional recovery of SCI mice by alleviating neuroinflammation, which provides a new intervention strategy for the neural regeneration and functional repair of SCI.


Assuntos
Gelatina , Ácido Hialurônico , Janus Quinase 2 , Doenças Neuroinflamatórias , Recuperação de Função Fisiológica , Traumatismos da Medula Espinal , Traumatismos da Medula Espinal/tratamento farmacológico , Traumatismos da Medula Espinal/metabolismo , Animais , Camundongos , Recuperação de Função Fisiológica/efeitos dos fármacos , Ácido Hialurônico/química , Ácido Hialurônico/farmacologia , Doenças Neuroinflamatórias/tratamento farmacológico , Gelatina/química , Gelatina/farmacologia , Janus Quinase 2/metabolismo , Dextranos/química , Alicerces Teciduais/química , Microesferas , Fator de Transcrição STAT3/metabolismo , Microglia/efeitos dos fármacos , Microglia/metabolismo , Regeneração Nervosa/efeitos dos fármacos , Metaloproteinase 9 da Matriz/metabolismo , Modelos Animais de Doenças , Neurogênese/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Metaloproteinase 2 da Matriz/metabolismo , Hidrogéis/química , Hidrogéis/farmacologia
16.
Int J Biol Macromol ; 267(Pt 1): 131288, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38565365

RESUMO

The unpredictable release behavior of metal nanoparticles/metal ions from metal nanoparticle-loaded hydrogels, without a suitable in situ detection method, is resulting in serious cytotoxicity. To optimize the preparation and design of antibacterial hydrogels for in situ detection of metal nanoparticles, an in-situ detection platform based on the fluorescence signal change caused by the potential surface energy transfer of silver nanoparticles (AgNPs) and carbon dots (CD) through silver mirror reaction and Schiff base reaction was established. The antimicrobial test results show that the composite antimicrobial hydrogel, with lower dosages of AgNPs and CD, exhibited a higher inhibition rate of 99.1 % against E. coli and 99.8 % against S. aureus compared to the single antimicrobial component. This suggests a potential synergistic antimicrobial activity. Furthermore, the fluorescence detection platform was established with a difference of <3 µg between detected values and actual values over a period of 72 h. This demonstrates the excellent in situ detection capability of the hydrogel in antimicrobial-related applications.


Assuntos
Antibacterianos , Dextranos , Escherichia coli , Hidrogéis , Nanopartículas Metálicas , Prata , Staphylococcus aureus , Prata/química , Nanopartículas Metálicas/química , Antibacterianos/farmacologia , Antibacterianos/química , Hidrogéis/química , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Dextranos/química , Testes de Sensibilidade Microbiana , Corantes Fluorescentes/química , Técnicas Biossensoriais/métodos
17.
Nutrients ; 16(7)2024 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-38612988

RESUMO

The goblet cells of the gastrointestinal tract (GIT) produce glycoproteins called mucins that form a protective barrier from digestive contents and external stimuli. Recent evidence suggests that the milk fat globule membrane (MFGM) and its milk phospholipid component (MPL) can benefit the GIT through improving barrier function. Our objective was to compare the effects of two digested MFGM ingredients with or without dextran sodium sulfate (DSS)-induced barrier stress on mucin proteins. Co-cultured Caco-2/HT29-MTX intestinal cells were treated with in vitro digests of 2%, 5%, and 10% (w/v) MFGM or MPL alone for 6 h or followed by challenge with 2.5% DSS (6 h). Transepithelial electrical resistance and fluorescein isothiocyanate (FITC)-dextran (FD4) permeability measurements were used to measure changes in barrier integrity. Mucin characterization was performed using a combination of slot blotting techniques for secreted (MUC5AC, MUC2) and transmembrane (MUC3A, MUC1) mucins, scanning electron microscopy (SEM), and periodic acid Schiff (PAS)/Alcian blue staining. Digested MFGM and MPL prevented a DSS-induced reduction in secreted mucins, which corresponded to the prevention of DSS-induced increases in FD4 permeability. SEM and PAS/Alcian blue staining showed similar visual trends for secreted mucin production. A predictive bioinformatic approach was also used to identify potential KEGG pathways involved in MFGM-mediated mucosal maintenance under colitis conditions. This preliminary in silico evidence, combined with our in vitro findings, suggests the role of MFGM in inducing repair and maintenance of the mucosal barrier.


Assuntos
Dextranos , Fluoresceína-5-Isotiocianato/análogos & derivados , Glicolipídeos , Glicoproteínas , Gotículas Lipídicas , Humanos , Células CACO-2 , Azul Alciano , Glicoproteínas/farmacologia , Células Epiteliais , Mucinas
18.
Neurochem Res ; 49(5): 1322-1330, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38478218

RESUMO

Microdialysis is applied in neurointensive care to monitor cerebral glucose metabolism. If recoverable, macromolecules may also serve as biomarkers in brain disease and provide clues to their passage across the blood-brain barrier. Our study aimed to investigate the in vitro recovery of human micro- and macromolecules using microdialysis catheters and perfusion fluids approved for clinical use. In vitro microdialysis of a bulk solution containing physiological or supraphysiological concentrations of glucose, lactate, pyruvate, human IgG, serum albumin, and hemoglobin was performed using two different catheters and perfusion fluids. One had a membrane cut-off of 20 kDa and was used with a standard CNS perfusion fluid, and the other had a membrane cut-off of 100 kDa and was perfused with the same solution supplemented with dextran. The flow rate was 0.3 µl/min. We used both push and push-pull methods. Dialysate samples were collected at 2-h intervals for 6 h and analyzed for relative recovery of each substance. The mean relative recovery of glucose, pyruvate, and lactate was > 90% in all but two sets of experiments. In contrast, the relative recovery of human IgG, serum albumin, and hemoglobin from both bulk solutions was below the lower limit of quantification (LLOQ). Using a push-pull method, recovery of human IgG, serum albumin, and hemoglobin from a bulk solution with supraphysiological concentrations were above LLOQ but with low relative recovery (range 0.9%-1.6%). In summary, exchanging the microdialysis setup from a 20 kDa catheter with a standard perfusion fluid for a 100 kDa catheter with a perfusion solution containing dextran did not affect the relative recovery of glucose and its metabolites. However, it did not result in any useful recovery of the investigated macromolecules at physiological levels, either with or without a push-pull pump system.


Assuntos
Lesões Encefálicas , Dextranos , Humanos , Lesões Encefálicas/metabolismo , Microdiálise/métodos , Perfusão/métodos , Glucose/metabolismo , Lactatos , Piruvatos , Albumina Sérica , Hemoglobinas , Imunoglobulina G
19.
Dig Dis Sci ; 69(4): 1242-1252, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38441784

RESUMO

BACKGROUND: Intestinal barrier dysfunction in acute pancreatitis (AP) may progress to systemic inflammatory response syndrome (SIRS) and multi-organ failures by causing bacterial translocation. Larazotide acetate (LA) is a molecule that acts as a tight junction (TJ) regulator by blocking zonulin (Zo) receptors in the intestine. AIMS: In our study, we aimed to investigate the effects of LA on intestinal barrier dysfunction and bacterial translocation in the AP model in rats. METHODS: Thirty-two male Sprague-Dawley rats were divided into 4 groups; control, larazotide (LAR), AP, and AP + LAR. The AP model was created by administering 250 mg/100 g bm L-Arginine intraperitoneally 2 times with an hour interval. AP + LAR group received prophylactic 0.01 mg/mL LA orally for 7 days before the first dose of L-Arginine. For intestinal permeability analysis, fluorescein isothiocyanate-dextran (FITC-Dextran) was applied to rats by gavage. The positivity of any of the liver, small intestine mesentery, and spleen cultures were defined as bacterial translocation. Histopathologically damage and zonulin immunoreactivity in the intestine were investigated. RESULTS: Compared to the control group, the intestinal damage scores, anti-Zo-1 immunoreactivity H-Score, serum FITC-Dextran levels and bacterial translocation frequency (100% versus 0%) in the AP group were significantly higher (all p < 0.01). Intestinal damage scores, anti-Zo-1 immunoreactivity H-score, serum FITC-Dextran levels, and bacterial translocation frequency (50% versus 100%) were significantly lower in the AP + LAR group compared to the AP group (all p < 0.01). CONCLUSIONS: Our findings show that LA reduces the increased intestinal permeability and intestinal damage by its effect on Zo in the AP model in rats, and decreases the frequency of bacterial translocation as a result of these positive effects.


Assuntos
Dextranos , Fluoresceína-5-Isotiocianato/análogos & derivados , Enteropatias , Pancreatite , Ratos , Masculino , Animais , Pancreatite/metabolismo , Mucosa Intestinal/metabolismo , Ratos Sprague-Dawley , Função da Barreira Intestinal , Translocação Bacteriana , Doença Aguda , Oligopeptídeos/farmacologia , Enteropatias/metabolismo , Arginina , Permeabilidade
20.
Phys Chem Chem Phys ; 26(14): 10546-10556, 2024 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-38506647

RESUMO

The emergence of phase separation in both intracellular biomolecular condensates (membrane-less organelles) and in vitro aqueous two-phase systems (ATPS) relies on the formation of immiscible water-based phases/domains. The solvent properties and arrangement of hydrogen bonds within these domains have been shown to differ and can be modulated with the addition of various inorganic salts and osmolytes. The naturally occuring osmolyte, trimethylamine-N-oxide (TMAO), is well established as a biological condensate stabilizer whose presence results in enhanced phase separation of intracellular membrane-less compartments. Here, we show the unique effect of TMAO on the mechanism of phase separation in model PEG-600-Dextran-75 ATPS using dynamic and static light scattering in conjunction with ATR-FTIR and solvatochromic analysis. We observe that the presence of TMAO may enhance or destabilize phase separation depending on the concentration of phase forming components. Additionally, the behavior and density of mesoscopic polymer agglomerates, which arise prior to macroscopic phase separation, are altered by the presence and concentration of TMAO.


Assuntos
Dextranos , Polietilenoglicóis , Polietilenoglicóis/química , Dextranos/química , Separação de Fases , Polímeros/química , Água/química , Metilaminas/química
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