RESUMEN
Anthocyanins (AC) are vulnerable to degradation when affected by external factors. The present study employed ultrasound-assisted glycosylation of ovalbumin (OVA) and dextran (Dex) to generate conjugate carrier for AC to improve its stability. The results showed that sonication significantly improved the progression of Maillard reaction to OVA. Compared to traditional glycosylation, ultrasound treatment showed a higher degree of grafting, a lower number of free-SH, and smaller particle size and uniform distribution. The SDS-PAGE results indicated covalent interaction. Intrinsic fluorescence (INF), Fourier transform infrared spectroscopy (FTIR), and Circular dichroism (CD) analysis results suggested that ultrasound-assisted glycosylation altered the OVA structure. The scanning electron microscope (SEM) and X-ray diffractometer (XRD) observed that the ultrasound-assisted complex had a more compact and smoother structure and protein unfolding were better. The protein solubility increased significantly after glycosylation. Thermal gravimetric analysis (TGA) and Differential scanning calorimetry (DSC) indicated that the glycosylated conjugates can significantly improve the thermal stability of AC In addition, the AC showed an improved processing and storage stability when conjugated with glycosylated carrier. The glycosylated protein-anthocyanins complex may help provide new ideas and scientific basis for the development of naturally sourced anthocyanins-relevant products in pharmaceutical and food industry applications.
Asunto(s)
Antocianinas , Dextranos , Ovalbúmina , Glicosilación , Dextranos/química , Ovalbúmina/química , Antocianinas/química , Ondas Ultrasónicas , Solubilidad , Portadores de Fármacos/químicaRESUMEN
Dental caries is a worldwide public healthcare concern, and is closely related to the acidic environment that caused by bacterial decomposition of food. In this study, a two-step ion exchange liquid-phase stripping method was applied to strip out vermiculite (VMT) nanosheets, then amorphous calcium phosphate (ACP) and dextran were inserted between the VMT nanosheets interlayer to obtain a composite two-dimension nanosheets (VMT/ACP/Dextran). VMT/ACP/Dextran composite nanosheets exhibited excellent biocompatibility and could provide exogenous Ca2+and PO43- from ACP, provide SiO44-, Mg2+, Fe2+ and obtain buffering pH and antibacterial properties from VMT, as well as improve suspension stability and targeting Streptococcus mutans through glucan. The in vitro study showed that the composite materials could promote the mineralization and sealing of dentin tubules by releasing active ions, buffer pH 4.5 (a value close to the pH in the dental plaque environment) to pH 6.6-7.1 (values close to the pH in human saliva) through ion exchange, and exert antibacterial effects by targeting Streptococcus mutans and exerting oxidase like and peroxidase like activities to produce reactive oxygen species (ROS). The in vivo animal study showed that daily cleaning teeth using VMT/ACP/Dextran composite nanosheets could effectively reduce the incidence rate and severity of dental caries in rats. Taking together, the developed VMT/ACP/Dextran composite nanosheets, which integrated the excellent properties of VMT, ACP and dextran, can effectively prevent dental caries through a combination of factors such as buffering acids, antibacterial properties, and promoting calcification, and may be used as an active ingredient for daily oral hygiene or filling materials to prevent and treat dental caries.
Asunto(s)
Antibacterianos , Fosfatos de Calcio , Caries Dental , Dentina , Dextranos , Streptococcus mutans , Caries Dental/prevención & control , Caries Dental/microbiología , Dextranos/química , Dextranos/farmacología , Animales , Antibacterianos/farmacología , Antibacterianos/química , Concentración de Iones de Hidrógeno , Fosfatos de Calcio/química , Fosfatos de Calcio/farmacología , Streptococcus mutans/efectos de los fármacos , Dentina/química , Dentina/efectos de los fármacos , Ratas , Nanoestructuras/química , Humanos , Masculino , Ratas Sprague-Dawley , Especies Reactivas de Oxígeno/metabolismoRESUMEN
Peanut protein isolate (PPI) has high nutritional value, but its poor function limits its application in the food industry. In this study, peanut protein isolate was modified by enzymatic hydrolysis combined with glycation. The structure, emulsification and interface properties of peanut protein isolate hydrolysate (HPPI) and dextran (Dex) conjugate (HPPI-Dex) were studied. In addition, the physicochemical properties, rheological properties, and stability of the emulsion were also investigated. The results showed that the graft degree increased with the increase of Dex ratio. Fourier transform infrared spectroscopy (FTIR) confirmed that the glycation of HPPI and Dex occurred. The microstructure showed that the structure of HPPI-Dex was expanded, and the molecular flexibility was enhanced. When the ratio of HPPI to Dex was 1:3, the emulsifying activity and the interface pressure of glycated HPPI reached the highest value, and the emulsifying activity (61.08 m2/g) of HPPI-Dex was 5.28 times that of PPI. The HPPI-Dex stabilized emulsions had good physicochemical properties and rheological properties. In addition, HPPI-Dex stabilized emulsions had high stability under heat treatment, salt ion treatment and freeze-thaw cycle. According to confocal laser scanning microscopy (CLSM), the dispersion of HPPI-Dex stabilized emulsions was better after 28 days of storage. This study provides a theoretical basis for developing peanut protein emulsifier and further expanding the application of peanut protein in food industry.
Asunto(s)
Arachis , Dextranos , Emulsiones , Proteínas de Plantas , Reología , Emulsiones/química , Arachis/química , Hidrólisis , Dextranos/química , Proteínas de Plantas/química , Glicosilación , Espectroscopía Infrarroja por Transformada de Fourier , Emulsionantes/química , Hidrolisados de Proteína/químicaRESUMEN
Hierarchical compartmentalization responding to changes in intracellular and extracellular environments is ubiquitous in living eukaryotic cells but remains a formidable task in synthetic systems. Here we report a two-level compartmentalization approach based on a thermo-responsive aqueous two-phase system (TR-ATPS) comprising poly(N-isopropylacrylamide) (PNIPAM) and dextran (DEX). Liquid membraneless compartments enriched in PNIPAM are phase-separated from the continuous DEX solution via liquid-liquid phase separation at 25 °C and shrink dramatically with small second-level compartments generated at the interface, resembling the structure of colloidosome, by increasing the temperature to 35 °C. The TR-ATPS can store biomolecules, program the spatial distribution of enzymes, and accelerate the overall biochemical reaction efficiency by nearly 7-fold. The TR-ATPS inspires on-demand, stimulus-triggered spatiotemporal enrichment of biomolecules via two-level compartmentalization, creating opportunities in synthetic biology and biochemical engineering.
Asunto(s)
Resinas Acrílicas , Dextranos , Temperatura , Resinas Acrílicas/química , Dextranos/química , Agua/química , Biología Sintética/métodosRESUMEN
It has been reported that the modification of immobilized glyoxyl-ficin with aldehyde dextran can promote steric hindrances that greatly reduce the activity of the immobilized protease against hemoglobin, while the protease still maintained a reasonable level of activity against casein. In this paper, we studied if this effect may be different depending on the amount of ficin loaded on the support. For this purpose, both the moderately loaded and the overloaded glyoxyl-ficin biocatalysts were prepared and modified with aldehyde dextran. While the moderately loaded biocatalyst had a significantly reduced activity, mainly against hemoglobin, the activity of the overloaded biocatalyst was almost maintained. This suggests that aldehyde dextran was able to modify areas of the moderately loaded enzyme that were not available when the enzyme was overloaded. This modification promoted a significant increase in biocatalyst stability for both biocatalysts, but the stability was higher for the overloaded biocatalyst (perhaps due to a combination of inter- and intramolecular crosslinking).
Asunto(s)
Aldehídos , Dextranos , Enzimas Inmovilizadas , Ficaína , Dextranos/química , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Ficaína/química , Ficaína/metabolismo , Aldehídos/química , Hemoglobinas/química , Hemoglobinas/metabolismo , Biocatálisis , Especificidad por Sustrato , Caseínas/química , Caseínas/metabolismo , Estabilidad de EnzimasRESUMEN
The precise assessment of vascular heterogeneity in brain tumors is vital for diagnosing, grading, predicting progression, and guiding treatment decisions. However, currently, there is a significant shortage of high-resolution imaging approaches. Herein, we propose a contrast-enhanced susceptibility-weighted imaging (CE-SWI) utilizing the minimalist dextran-modified Fe3O4 nanoparticles (Dextran@Fe3O4 NPs) for ultrahigh-resolution mapping of vasculature in brain tumors. The Dextran@Fe3O4 NPs are prepared via a facile coprecipitation method under room temperature, and exhibit small hydrodynamic size (28 nm), good solubility, excellent biocompatibility, and high transverse relaxivity (r2*, 159.7 mM-1 s-1) under 9.4 T magnetic field. The Dextran@Fe3O4 NPs-enhanced SWI can increase the contrast-to-noise ratio (CNR) of cerebral vessels to 2.5 times that before injection and achieves ultrahigh-spatial-resolution visualization of microvessels as small as 0.1 mm in diameter. This advanced imaging capability not only allows for the detailed mapping of both enlarged peritumoral drainage vessels and the intratumoral microvessels, but also facilitates the sensitive imaging detection of vascular permeability deterioration in a C6 cells-bearing rat glioblastoma model. Our proposed Dextran@Fe3O4 NPs-enhanced SWI provides a powerful imaging technique with great clinical translation potential for the precise theranostics of brain tumors.
Asunto(s)
Neoplasias Encefálicas , Dextranos , Imagen por Resonancia Magnética , Nanopartículas de Magnetita , Neoplasias Encefálicas/diagnóstico por imagen , Neoplasias Encefálicas/patología , Animales , Imagen por Resonancia Magnética/métodos , Nanopartículas de Magnetita/química , Dextranos/química , Ratas , Medios de Contraste/química , Humanos , Línea Celular Tumoral , Tamaño de la PartículaRESUMEN
Tight junction disruption can lead to pathogenesis of various diseases without therapeutic strategy to recover intestinal barrier integrity. The main objective of this study is to demonstrate the effect of Solanum melongena L. extract (SMLE) on intestinal tight junction recovery and its underlying mechanism. Intestinal barrier function is attenuated by Ca2+ depletion. SMLE treatment increased TER value across T84 cell monolayers. Permeability assay reveals that Ca2+ depletion promotes 4-kDa FITC-dextran permeability, but not 70-kDa FITC-dextran. SMLE suppresses the rate of 4-kDa FITC-dextran permeability, indicating that SMLE inhibits paracellular leak pathway permeability. SMLE-mediated TER increase and leak pathway suppression are abolished by neither calcium/calmodulin-dependent protein kinase kinase ß (CaMKKß) inhibitor nor AMP-activated protein kinase (AMPK) inhibitor. Furthermore, mammalian target of rapamycin (mTOR) and extracellular signal-regulated kinase (ERK) inhibitors have no effects on SMLE-mediated TER increase and leak pathway suppression. Interestingly, SMLE is unable to enhance TER value and diminish leak pathway permeability in T84 cell monolayers pre-treated with sirtuin-1 (SIRT-1) inhibitor. Immunofluorescence staining reveals that SMLE enhances re-assembly of tight junction proteins, including occludin and ZO-1 to intercellular space but this effect is abolished by SIRT-1 inhibitor. These data suggest that SMLE promotes intestinal tight junction re-assembly via SIRT-1-dependent manner.
Asunto(s)
Extractos Vegetales , Sirtuina 1 , Uniones Estrechas , Sirtuina 1/metabolismo , Uniones Estrechas/efectos de los fármacos , Uniones Estrechas/metabolismo , Extractos Vegetales/farmacología , Humanos , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/metabolismo , Ocludina/metabolismo , Permeabilidad/efectos de los fármacos , Calcio/metabolismo , Línea Celular , Proteína de la Zonula Occludens-1/metabolismo , Dextranos , Serina-Treonina Quinasas TOR/metabolismo , Fluoresceína-5-Isotiocianato/análogos & derivadosRESUMEN
Motile droplets using Marangoni convection are attracting attention for their potential as cell-mimicking small robots. However, the motion of droplets relative to the internal and external environments that generate Marangoni convection has not been quantitatively described. In this study, we used an aqueous two-phase system [poly(ethylene glycol) (PEG) and dextran] in an elongated chamber to generate motile dextran droplets in a constant PEG concentration gradient. We demonstrated that dextran droplets move by Marangoni convection, resulting from the PEG concentration gradient and the active transport of PEG and dextran into and out of the motile dextran droplet. Furthermore, by spontaneously incorporating long DNA into the dextran droplets, we achieved cell-like motility changes controlled by coexisting environment-sensing molecules. The DNA changes its position within the droplet and motile speed in response to external conditions. In the presence of Mg2+, the coil-globule transition of DNA inside the droplet accelerates the motile speed due to the decrease in the droplet's dynamic viscosity. Globule DNA condenses at the rear part of the droplet along the convection, while coil DNA moves away from the droplet's central axis, separating the dipole convections. These results provide a blueprint for designing autonomous small robots using phase-separated droplets, which change the mobility and molecular distribution within the droplet in reaction with the environment. It will also open unexplored areas of self-assembly mechanisms through phase separation under convections, such as intracellular phase separation.
Asunto(s)
ADN , Dextranos , Polietilenglicoles , Dextranos/química , Polietilenglicoles/química , ADN/química , Viscosidad , SolucionesRESUMEN
Dextran-type α-glucans have been known as non-digestible ingredients that can be considered prebiotics to promote colon health. However, recent studies have revealed that various α-linked glucosyl units are hydrolyzed to glucose by small intestinal α-glucosidases. This study analyzed the structural characteristics of exopolysaccharides (EPSs) from Weissella species, and the hydrolysis properties at both in vitro/in vivo levels were investigated. Compared with a previous in vitro digestion model using fungal α-hydrolytic enzymes, dextrans, which mainly consist of α-1,6 linkages with small amounts of α-1,3 linked glucose units, were slowly hydrolyzed to glucose by mammalian mucosal α-glucosidases, resulting in attenuation of the initial glycemic response following administration of EPS samples to mice via oral gavage. The results of this study demonstrate the concept of dextran-type α-glucans as glycemic carbohydrates rather than dietary fibers or prebiotics. Slowly digestible dextrans can be applied as a functional ingredient to regulate postprandial glucose delivery throughout the gastrointestinal tract.
Asunto(s)
Dextranos , Intestino Delgado , alfa-Glucosidasas , Animales , Ratones , Hidrólisis , Intestino Delgado/metabolismo , alfa-Glucosidasas/metabolismo , Dextranos/química , Glucemia/metabolismo , Masculino , Glucosa/metabolismoRESUMEN
Theranostic sutures are derived from innovative ideas to enhance wound healing results by adding wound diagnostics and therapeutics to typical sutures by functionalizing them with additional materials. Here, we present a new direct electrospinning method for the fast, continuous, inexpensive, and high-throughput production of versatile nanofibrous-coated suture threads, with precise control over various essential microstructural and physical characteristics. The thickness of the coating layer and the alignment of nanofibers with the thread's direction can be adjusted by the user by varying the spooling speed and the displacement between the spinneret needle and thread. To show the flexibility of our method for a range of different materials selected, gelatin, polycaprolactone, silk fibroin, and PEDOT:PSS (poly(3,4-ethylene dioxythiophene):poly(styrene sulfonate)) were the resultant nanofibers characterized by scanning electron microscopy (SEM) imaging and conductivity tests. In a series of in vitro and ex vivo tests (pig skin), sutures were successfully tested for their flexibility and mechanical properties when used as weaving and knotting sutures, and their biocompatibility with a keratinocyte cell line. For temperature-based drug-releasing tests, two fluorescent molecules as drug models with high and low molecular weight, namely fluorescein isothiocyanate-dextran (20 kDa) and rhodamine B (470 Da), were used, and their steady release with incremental increase of temperature to 37 °C over 120 min was seen, which is appropriate for bacterial treatment drugs. Given the advantages of the presented technique, it seems to have promising potential to be used in future medical applications for wound closure and bacterial infection treatment via a temperature-triggered drug release strategy.
Asunto(s)
Nanofibras , Rodaminas , Suturas , Cicatrización de Heridas , Nanofibras/química , Animales , Cicatrización de Heridas/efectos de los fármacos , Humanos , Rodaminas/química , Porcinos , Poliésteres/química , Dextranos/química , Gelatina/química , Nanoporos , Fluoresceína-5-Isotiocianato/química , Materiales Biocompatibles Revestidos/química , Queratinocitos/citología , Queratinocitos/metabolismo , Fibroínas/química , Línea CelularRESUMEN
Toll-like receptors (TLRs) are a class of pattern recognition receptors (PRRs) crucial for the detection of infections and activation of downstream signaling pathways that lead to the production of pro-inflammatory cytokines and interferons. The TLR pathway is an attractive actively studied target pathway. Because of their strong immunostimulatory activity, TLRs are thought to be a "double-edged sword" for systemic treatment, even in the cancer field. To solve this, we have developed dextran-based TAM targeting activating conjugate (D-TAC) technology, which successfully uses tumor-associated macrophages (TAMs) to deliver the TLR7 agonist DSP-0509. We used low molecular weight dextran to target CD206 high M2-type macrophages, activate them, and induce a change in phenotype to antitumor M1-type macrophages with rapid clearance from the body and astonishing antitumor activity. We also demonstrated that the antitumor effect of our best drug candidate 5DEX-0509R is dependent on the abundance of TAMs, which is consistent with their mechanism of action. We believe that 5DEX-0509R generated by D-TAC technology can be a clinically applicable immunotherapy targeting the TLR signaling pathway.
Asunto(s)
Antineoplásicos , Nanomedicina , Receptor Toll-Like 7 , Macrófagos Asociados a Tumores , Animales , Ratones , Receptor Toll-Like 7/agonistas , Receptor Toll-Like 7/metabolismo , Macrófagos Asociados a Tumores/efectos de los fármacos , Macrófagos Asociados a Tumores/inmunología , Macrófagos Asociados a Tumores/metabolismo , Antineoplásicos/farmacología , Antineoplásicos/química , Dextranos/química , Dextranos/farmacología , Ratones Endogámicos C57BL , Humanos , Línea Celular Tumoral , Femenino , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Macrófagos/inmunologíaRESUMEN
The development of tissue adhesives with good biocompatibility and potent antimicrobial properties is crucial for addressing the high incidence of surgical site infections in emergency and clinical settings. Herein, an injectable hydrogel adhesive composed of chitosan biguanidine (CSG), oxidized dextran (ODex) and tannin (TA) was synthesized primarily through Schiff-base reactions, hydrogen bonding, and electrostatic interactions. TA was introduced into the CSG/ODex hydrogel to prepare a physicochemically double cross-linked hydrogel. The hydrogel formulation incorporating 2 wt% TA (CSG/ODex-TA2) exhibited rapid gelation, moderate mechanical properties, good tissue adhesion, and sustained release behavior of TA. Both in vitro and in vivo studies demonstrated that CSG/ODex-TA2 showed significantly enhanced adhesion and antibacterial effectiveness compared to the CSG/ODex hydrogel and commercial fibrin glue. Leveraging the positive charge of CSG, the CSG/ODex-TA2 hydrogel demonstrated a strong contact antibacterial effect, while the sustained release of TA provided diffusion antibacterial capabilities. By integrating contact and diffusion antibacterial mechanisms into the hydrogel, a promising approach was developed to boost antibacterial efficiency and accelerate the healing of wounds infected with methicillin-resistant Staphylococcus aureus (MRSA). The CSG/ODex-TA2 hydrogel has excellent biocompatibility, hemostatic properties, and antibacterial capabilities, making it a promising candidate for improving in vivo wound care and combating bacterial infections.
Asunto(s)
Antibacterianos , Quitosano , Hidrogeles , Staphylococcus aureus Resistente a Meticilina , Adhesivos Tisulares , Cicatrización de Heridas , Quitosano/química , Quitosano/farmacología , Hidrogeles/química , Hidrogeles/farmacología , Cicatrización de Heridas/efectos de los fármacos , Animales , Antibacterianos/farmacología , Antibacterianos/química , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Adhesivos Tisulares/química , Adhesivos Tisulares/farmacología , Ratones , Biguanidas/química , Biguanidas/farmacología , Dextranos/química , Dextranos/farmacología , Taninos/química , Taninos/farmacología , Humanos , Infecciones Estafilocócicas/tratamiento farmacológico , Pruebas de Sensibilidad Microbiana , MasculinoRESUMEN
Dextransucrases play a crucial role in the production of dextran from economical sucrose; therefore, there is a pressing demand to explore novel dextransucrases with better performance. This study characterized a dextransucrase enzyme, LmDexA, which was identified from the Leuconostoc mesenteroides NN710. This bacterium was isolated from the soil of growing dragon fruit in Guangxi province, China. We successfully constructed six different N-terminal truncated variants through sequential analysis. Additionally, a truncated variant, ΔN190LmDexA, was constructed by removing the 190 amino acids fragment from the N-terminal. This truncated variant was then successfully expressed heterologously in Escherichia coli and purified. The purified ΔN190LmDexA demonstrated optimal hydrolysis activity at a pH of 5.6 and a temperature of 30 °C. Its maximum specific activity was measured to be 126.13 U/mg, with a Km of 13.7 mM. Results demonstrated a significant improvement in the heterologous expression level and total enzyme activity of ΔN190LmDexA. ΔN190LmDexA exhibited both hydrolytic and transsaccharolytic enzymatic activities. When sucrose was used as the substrate, it primarily produced high-molecular-weight dextran (>400 kDa). However, upon the addition of maltose as a receptor, it resulted in the production of a significant amount of oligosaccharides. Our results can provide valuable information for enhancing the characteristics of recombinant dextransucrase and potentially converting sucrose into high-value-added dextran and oligosaccharides.
Asunto(s)
Clonación Molecular , Glucosiltransferasas , Leuconostoc mesenteroides , Glucosiltransferasas/genética , Glucosiltransferasas/metabolismo , Glucosiltransferasas/química , Leuconostoc mesenteroides/enzimología , Leuconostoc mesenteroides/genética , Dextranos/química , Dextranos/biosíntesis , Dextranos/metabolismo , Hidrólisis , Concentración de Iones de Hidrógeno , Escherichia coli/genética , Mutación , Especificidad por Sustrato , Sacarosa/metabolismo , Cinética , TemperaturaRESUMEN
The perivascular space (PVS) surrounds cerebral blood vessels and plays an important role in clearing waste products from the brain. Their anatomy and function have been described for arteries, but PVS around veins remain poorly characterized. Using in vivo 2-photon imaging in mice, we determined the size of the PVS around arteries and veins, and their connection with the subarachnoid space. After infusion of 70 kD FITC-dextran into the cerebrospinal fluid via the cisterna magna, labeled PVS were evident around arteries, but veins showed less frequent labeling of the PVS. The size of the PVS correlated with blood vessel size for both pial arteries and veins, but not for penetrating vessels. The PVS around pial arteries and veins was separated from the subarachnoid space by a thin meningeal layer, which did not form a barrier for the tracer. In vivo, FITC-dextran signal was observed adjacent to the vessel wall, but minimally within the wall itself. Post-mortem, there was a significant shift in the tracer's location within the arterial wall, extending into the smooth muscle layer. Taken together, these findings suggest that the PVS around veins has a limited role in the exchange of solutes between CSF and brain parenchyma.
Asunto(s)
Encéfalo , Arterias Cerebrales , Animales , Ratones , Encéfalo/irrigación sanguínea , Arterias Cerebrales/anatomía & histología , Sistema Glinfático , Fluoresceína-5-Isotiocianato/análogos & derivados , Dextranos , Masculino , Venas Cerebrales/anatomía & histología , Ratones Endogámicos C57BL , Espacio SubaracnoideoRESUMEN
Ensuring good definition of scaffolds used for 3D cell culture is a prominent challenge that hampers the development of tissue engineering platforms. Since dextran repels cell adhesion, using dextran-based materials biofunctionalized through a bottom-up approach allows for precise control over material definition. Here, we report the design of dextran hydrogels displaying a fully interconnected macropore network for the culture of vascular spheroids in vitro. We biofunctionalized the hydrogels with the RGD peptide sequence to promote cell adhesion. We used an affinity peptide pair, the E/K coiled coil, to load the gels with epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF). Dual functionalization with adhesive and proliferative cues allows vascular spheroids to colonize naturally cell-repellant dextran. In supplement-depleted medium, we report improved colonization of the macropores compared to that of unmodified dextran. Altogether, we propose a well-defined and highly versatile platform for tissue engineering and tissue vascularization applications.
Asunto(s)
Dextranos , Hidrogeles , Dextranos/química , Hidrogeles/química , Hidrogeles/farmacología , Humanos , Factor A de Crecimiento Endotelial Vascular/farmacología , Factor A de Crecimiento Endotelial Vascular/metabolismo , Factor A de Crecimiento Endotelial Vascular/química , Oligopéptidos/química , Oligopéptidos/farmacología , Ingeniería de Tejidos/métodos , Esferoides Celulares/citología , Esferoides Celulares/efectos de los fármacos , Esferoides Celulares/metabolismo , Adhesión Celular/efectos de los fármacos , Porosidad , Células Endoteliales de la Vena Umbilical Humana/efectos de los fármacos , Factor de Crecimiento Epidérmico/farmacología , Factor de Crecimiento Epidérmico/metabolismo , Neovascularización Fisiológica/efectos de los fármacos , Andamios del Tejido/química , Péptidos y Proteínas de Señalización Intercelular/farmacología , Péptidos/química , Péptidos/farmacologíaRESUMEN
Background: The blood-brain barrier (BBB) is a major bottleneck in delivering therapeutics to the brain. Treatment strategies to transiently open this barrier include focused ultrasound combined with intravenously injected microbubbles (FUS+MB) and targeting of molecules that regulate BBB permeability. Methods: Here, we investigated BBB opening mediated by the claudin-5 binder cCPEm (a microorganismal toxin in a truncated form) and FUS+MB at a centre frequency of 1 MHz, assessing dextran uptake, broadband emission, and endogenous immunoglobulin G (IgG) extravasation. Results: FUS+MB-induced BBB opening was detectable at a pressure ≥0.35 MPa when assessed for leakage of 10 and 70 kDa dextran, and at ≥0.2 MPa for uptake of endogenous IgG. Treating mice with 20 mg/kg cCPEm failed to open the BBB, and pre-treatment with cCPEm followed by FUS+MB at 0.2 and 0.3 MPa did not overtly increase BBB opening compared to FUS+MB alone. Using passive cavitation detection (PCD), we found that broadband emission correlated with the peak negative pressure (PNP) and dextran leakage, indicating the possibility of using broadband emission for developing a feedback controller to monitor BBB opening. Conclusions: Together, our study highlights the challenges in developing combinatorial approaches to open the BBB and presents an additional IgG-based histological detection method for BBB opening.
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Barrera Hematoencefálica , Claudina-5 , Microburbujas , Animales , Barrera Hematoencefálica/metabolismo , Ratones , Claudina-5/metabolismo , Inmunoglobulina G/metabolismo , Ondas Ultrasónicas , Ratones Endogámicos C57BL , Dextranos/química , Dextranos/farmacocinéticaRESUMEN
Leuconostoc citreum JZ-002 was extracted from artisanal orange wine. This strain was used to synthesize dextran with a purification extraction of 27.9 g/L. The resulting dextran had a molecular weight of 2.45 × 106 Da. A significant portion, amounting to 64 % of the structure, is constituted by the main chain, with α-(1,6) glycosidic bonds acting as the linkages. In contrast, the branched chain, comprising 34 % of the entire molecule, is characterized by the presence of α-(1,3) glycosidic bonds. The dextransucrase DsrB, believed to be accountable for the formation of the dextran backbone, was successfully cloned into the pET-28a-AcmA vector. The recombinant expression of the enzyme was achieved. Purified recombinant enzymes and immobilized in a single go using the gram-positive enhancer matrix (GEM). The maximum yield of dextran produced by suchimmobilized enzyme was 191.9 g/L. The composition featured a dextran connected via α-(1,6) glycosidic linkages. Molecular weight controlled synthesis was achieved with sucrose concentrations of 100-2000 mM and enzyme concentrations of 320-1280 U. The Mw of the synthesized dextran extended from 4680 to 1,320,000 Da. By controlling the ratio between enzyme concentration and sucrose concentration, dextrans with diverse Mw can be enzymatically generated.
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Dextranos , Glucosiltransferasas , Leuconostoc , Peso Molecular , Proteínas Recombinantes , Dextranos/química , Dextranos/biosíntesis , Glucosiltransferasas/química , Glucosiltransferasas/genética , Glucosiltransferasas/metabolismo , Leuconostoc/enzimología , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Sacarosa/químicaRESUMEN
Self-regeneration is a key function of living systems that needs to be recapitulated in vitro to create a living synthetic cell. A major limiting factor for protein self-regeneration in the PURE cell-free transcription-translation system is its high protein concentration, which far exceeds the system's protein synthesis rate. Here, we were able to drastically reduce the nonribosomal PURE protein concentration up to 97.3% while increasing protein synthesis efficiency. Although crowding agents were not effective in the original PURE formulation, we found that in highly dilute PURE formulations, addition of 6% dextran considerably increased protein synthesis rate and total protein yield. These new PURE formulations will be useful for many cell-free synthetic biology applications, and we estimate that PURE can now support the complete self-regeneration of all 36 nonribosomal proteins, which is a critical step toward the development of a universal biochemical constructor and living synthetic cell.
Asunto(s)
Sistema Libre de Células , Biosíntesis de Proteínas , Transcripción Genética , Sistema Libre de Células/metabolismo , Biología Sintética/métodos , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/biosíntesis , Dextranos/metabolismo , Dextranos/químicaRESUMEN
This study aims to investigate the factors effective in predicting the persistence of reflux after the first subureteric transurethral injection (STING) of dextranomer/hyaluronic acid copolymer in pediatric patients with vesicoureteral reflux. The data of patients without a previous history of surgery to treat vesicoureteral reflux and who underwent STING for the first time between September 2011 and November 2020 were investigated retrospectively. After considering exclusion criteria, of 199 patients, 127 patients and 180 renal units were suitable for inclusion. A renal unit-based evaluation was made. Age < 61 months (univariate: p = 0.001, multivariate: p = 0.015, HR: 2.352 (1.181-4.686), OR (95% CI)), moderate reflux level (grade 3) (univariate: p < 0.001, multivariate: p = 0.019, HR: 2.703 (1.177-6.209), OR (95% CI)), DRF (differential renal function) < 45 (univariate: p = 0.020, multivariate: p = 0.047, HR: 1.992 (1.009-3.935), OR (95% CI)), and UDR (ureteral diameter ratio) > 0.15 (univariate: p < 0.001, multivariate: p = 0.005, HR: 2.786 (1.368-5.672), OR (95% CI)) were found predictors of reflux persistence after STING surgery both univariate and multivariate analysis. High reflux level (grade 4-5) was statistically significant in univariate analysis (p < 0.001) but not statistically significant in multivariate analysis (p = 0.215). In our study, UDR and DRF were found to be factors affecting reflux persistence. UDR and DRF should be considered in order to predict reflux resolution in patients who will undergo STING.
Asunto(s)
Dextranos , Ácido Hialurónico , Reflujo Vesicoureteral , Humanos , Reflujo Vesicoureteral/terapia , Ácido Hialurónico/administración & dosificación , Dextranos/administración & dosificación , Femenino , Masculino , Preescolar , Estudios Retrospectivos , Lactante , Niño , Inyecciones , Resultado del TratamientoRESUMEN
PURPOSE: This study evaluated the outcome of pediatric patients with primary vesicoureteral reflux (VUR) and compared of the treatments between continued antibiotic prophylaxis (CAP) and endoscopic injection. METHODS: The clinical data of children diagnosed with primary vesicoureteral reflux from March 2015 to June 2020 who were treated with antibiotics or endoscopic injection were reviewed. Antibiotic was the first-chosen treatment after the diagnosis of VUR in children. Endoscopic treatment consisted of injection of dextran hyaluronic acid copolymer (DX/HA) into the ureteral opening under direct cystoscopy guidance. RESULTS: Fifty-two children (35 males, 17 females) were included in this study, and for a total 90 ureters (14 unilateral, 38 bilateral) were diagnosed with vesicoureteral reflux by Voiding cystourethrography (VCUG). Twenty-two children were treated with antibiotics (8 unilateral, 14 bilateral), for a total of 36 ureters; thirty children were treated by endoscopic injection (6 unilateral, 24 bilateral), for a total of 54 ureters. The injection surgery took 36 ± 17 min including duration of general anesthesia and circumcision and the hospital stay was 2.3 ± 1.3 days. All male patients underwent circumcision simultaneously. There were no drug and allergic reactions in the antibiotic group, and no postoperative complications occurred in the injection group. With 23 months (13-63 months) of mean follow-up, the resolution rate, defined as radiological disappearance of VUR, was 36.1% (13/36) in the antibiotic group and 57.4% (31/54) in the injection group (P = 0.048).Two cases of bilateral reflux in the injection group required a second injection before resolution could be achieved. Thus, the overall success rate of injection was 64.8% (35/54). 9 cases (9/18, 50%) in the antibiotic group had renal scars on DMSA scans, while this was seen in 20 cases (20/23, 86.9%) in the injection group. There was a statistically significant difference between the two groups (P = 0.010).The positive rates of ultrasound between the antibiotic group and the injection group were 45.5% (10/22) and 80.0% (24/30), respectively. There was a statistically significant difference between the two groups in positive rates of ultrasound (P = 0.010). CONCLUSIONS: Endoscopic injection is easy to operate with short surgical time and hospital stay, so it is a safe and feasible treatment. For the treatment of primary vesicoureteral reflux in children, the radiological resolution rate of endoscopic injection is better than antibiotic therapy. In this study, the presence of kidney scars on DMSA and the dilated of the collecting system on ultrasound are the indications for endoscopic injection.