RESUMEN
Melanoma either intrinsically possesses resistance or rapidly acquires resistance to anti-tumor therapy, which often leads to local recurrence or distant metastasis after resection. In this study, we found histone 3 lysine 27 (H3K27) demethylated by an inhibitor of histone methyltransferase EZH2 could epigenetically reverse the resistance to chemo-drug paclitaxel (PTX), or enhance the efficacy of immune checkpoint inhibitor anti-TIGIT via downregulating TIGIT ligand CD155. Next, to address the complexity in the combination of multiple bioactive molecules with distinct therapeutic properties, we developed a polysaccharides-based organohydrogel (OHG) configured with a heterogenous network. Therein, hydroxypropyl chitosan (HPC)-stabilized emulsions for hydrophobic drug entrapment were crosslinked with oxidized dextran (Odex) to form a hydrophilic gel matrix to facilitate antibody accommodation, which demonstrated a tunable sustained release profile by optimizing emulsion/gel volume ratios. As results, local injection of OHG loaded with EZH2 inhibitor UNC1999, PTX and anti-TIGIT did not only synergistically enhance the cytotoxicity of PTX, but also reprogrammed the immune resistance via bi-directionally blocking TIGIT/CD155 axis, leading to the recruitment of cytotoxic effector cells into tumor and conferring a systemic immune memory to prevent lung metastasis. Hence, this polysaccharides-based OHG represents a potential in-situ epigenetic-, chemo- and immunotherapy platform to treat unresectable metastatic melanoma.
Asunto(s)
Quitosano , Dextranos , Proteína Potenciadora del Homólogo Zeste 2 , Epigénesis Genética , Melanoma , Proteína Potenciadora del Homólogo Zeste 2/antagonistas & inhibidores , Proteína Potenciadora del Homólogo Zeste 2/metabolismo , Proteína Potenciadora del Homólogo Zeste 2/genética , Proteína Potenciadora del Homólogo Zeste 2/inmunología , Quitosano/química , Quitosano/análogos & derivados , Dextranos/química , Animales , Melanoma/tratamiento farmacológico , Melanoma/patología , Melanoma/inmunología , Ratones , Humanos , Epigénesis Genética/efectos de los fármacos , Paclitaxel/farmacología , Paclitaxel/química , Paclitaxel/uso terapéutico , Resistencia a Antineoplásicos/efectos de los fármacos , Hidrogeles/química , Línea Celular Tumoral , Receptores Inmunológicos/antagonistas & inhibidores , Receptores Inmunológicos/metabolismo , Antineoplásicos/farmacología , Antineoplásicos/químicaRESUMEN
Adipose tissue-derived adult stem (ADAS) cells and extracellular vesicle (EV) therapy offer promising avenues for treating neurodegenerative diseases due to their accessibility and potential for autologous cell transplantation. However, the clinical application of ADAS cells or EVs is limited by the challenge of precisely identifying them in specific regions of interest. This study compares two superparamagnetic iron oxide nanoparticles, differing mainly in size, to determine their efficacy for allowing non-invasive ADAS tracking via MRI/MPI and indirect labeling of EVs. We compared a USPIO (about 5 nm) with an SPIO (Resovist®, about 70 nm). A physicochemical characterization of nanoparticles was conducted using DLS, TEM, MRI, and MPI. ADAS cells were labeled with the two nanoparticles, and their viability was assessed via MTT assay. MRI detected labeled cells, while TEM and Prussian Blue staining were employed to confirm cell uptake. The results revealed that Resovist® exhibited higher transversal relaxivity value than USPIO and, consequently, allows for detection with higher sensitivity by MRI. A 200 µgFe/mL concentration was identified as optimal for ADAS labeling. MPI detected only Resovist®. The findings suggest that Resovist® may offer enhanced detection of ADAS cells and EVs, making it suitable for multimodal imaging. Preliminary results obtained by extracting EVs from ADAS cells labeled with Resovist® indicate that EVs retain the nanoparticles, paving the way to an efficient and multimodal detection of EVs.
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Tejido Adiposo , Células Madre Adultas , Vesículas Extracelulares , Nanopartículas Magnéticas de Óxido de Hierro , Imagen por Resonancia Magnética , Nanopartículas de Magnetita , Vesículas Extracelulares/química , Vesículas Extracelulares/metabolismo , Tejido Adiposo/citología , Humanos , Células Madre Adultas/citología , Células Madre Adultas/metabolismo , Nanopartículas Magnéticas de Óxido de Hierro/química , Imagen por Resonancia Magnética/métodos , Nanopartículas de Magnetita/química , Imagen Multimodal/métodos , Dextranos/química , Medios de Contraste/química , Células CultivadasRESUMEN
Based on the principle of cascade reaction, a fusion enzyme of dextransucrase and dextranase was designed without linker to catalyze the production of oligo-dextran with homogeneous molecular weight from sucrose in one catalytic step. Due to the different effects of temperature on the two components of the fusion enzyme, temperature served as the "toggle switch" for the catalytic efficiency of the two-level fusion enzyme, regulating the catalytic products of the fusion enzyme. Under optimal conditions, the fusion enzyme efficiently utilized 100 % of the sucrose, and the yield of oligo-dextran with a homogeneous molecular weight reached 70 %. The product has been purified and characterized. The probiotic potential of the product was evaluated by analyzing the growth of 10 probiotic species. Its cytotoxic and anti-inflammatory activities were also determined. The results showed that the long-chain oligo-dextran in this study had significantly better probiotic potential and anti-inflammatory activity compared to other oligosaccharides. This study provides a strategy for the application of oligo-dextran in the food and pharmaceutical industries.
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Dextranasa , Dextranos , Glucosiltransferasas , Temperatura , Dextranos/química , Dextranasa/metabolismo , Dextranasa/química , Dextranasa/genética , Glucosiltransferasas/metabolismo , Glucosiltransferasas/química , Proteínas Recombinantes de Fusión/química , Proteínas Recombinantes de Fusión/genética , Probióticos , Antiinflamatorios/farmacología , Antiinflamatorios/química , Animales , Sacarosa/química , Sacarosa/metabolismo , Peso MolecularRESUMEN
An ideal adhesive hydrogel must possess high adhesion to the native tissue, biocompatibility, eligible biodegradability, and good mechanical compliance with the substrate tissues. We constructed an interpenetrating double-network hydrogel containing polysaccharides (alginate and dextran) and nanosized spherical dendrimer by both physical and chemical crosslinking, thus endowing the hydrogel with a broad range of mechanical properties, adhesive properties, and biological functions. The double-network hydrogel has moderate pore sizes and swelling properties. The chelation of calcium ions significantly enhances the tensile and compressive properties. The incorporation of dendrimer improves both the mechanical and adhesive properties. This multicomponent interpenetrating network hydrogel has excellent biocompatibility, tunable mechanical and adhesive properties, and satisfied multi-functions to meet the complex requirements of wound healing and tissue engineering. The hydrogel exhibits promising corneal adhesion capabilities in vitro, potentially supplanting the need for sutures in corneal stromal surgery and mitigating the risks associated with donor corneal damage and graft rejection during corneal transplantation. This novel polysaccharide and dendrimer hydrogel also shows good results in sutureless keratoplasty, with high efficiency and reliability. Based on the clinical requirements for tissue bonding and wound closure, the hydrogel provides insight into solving the mechanical properties and adhesive strength of tissue adhesives.
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Alginatos , Dendrímeros , Dextranos , Hidrogeles , Adhesivos Tisulares , Alginatos/química , Hidrogeles/química , Dextranos/química , Dendrímeros/química , Adhesivos Tisulares/química , Animales , Trasplante de Córnea/métodos , Humanos , Materiales Biocompatibles/química , Materiales Biocompatibles/farmacología , Resistencia a la Tracción , Conejos , Córnea/cirugía , Cicatrización de Heridas/efectos de los fármacos , Reactivos de Enlaces Cruzados/químicaRESUMEN
Ficin has been immobilized at full loading on glyoxyl agarose beads. Then, ficin was blocked with 2,2'-dipyridyldisulfide. To be effective, the modification must be performed in the presence of 0.5 M urea, as the enzyme was not inhibited under standard conditions, very likely because the catalytic Cys was not fully exposed to the medium. Activity could be fully recovered by incubation with 1 M mercaptoethanol. This biocatalyst could hydrolyze hemoglobin and casein. The objective of this paper was to increase the enzyme specificity versus small proteins by generating steric hindrances to the access of large proteins. The step by step blocking via ionic exchange of the biocatalyst with aminated bovine serum albumin (BSA), aldehyde dextran and a second layer of aminated BSA produced a biocatalyst that maintained its activity versus small synthetic substrates, increased the biocatalyst stability, while reduced its activity to over 50 % versus casein. Interestingly, this treatment almost fully annulled the activity versus hemoglobin, more effectively at 37 °C than at 55 °C. The biocatalyst could be reused 5 times without changes in activity. The changes could be caused by steric hindrances, but it cannot be discarded some changes in enzyme sequence specificity caused by the modifications.
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Caseínas , Dextranos , Enzimas Inmovilizadas , Ficaína , Hemoglobinas , Hemoglobinas/química , Hemoglobinas/metabolismo , Caseínas/química , Caseínas/metabolismo , Dextranos/química , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Ficaína/química , Ficaína/metabolismo , Especificidad por Sustrato , Bovinos , Animales , Albúmina Sérica Bovina/química , Albúmina Sérica Bovina/metabolismo , Sefarosa/química , Aldehídos/química , Aldehídos/metabolismo , Estabilidad de Enzimas , GlioxilatosRESUMEN
The search for novel exopolysaccharides (EPS) with targeted functionalities is currently a topic of great interest. This study aimed to investigate the chemical characteristics and technological properties of a novel EPS (named EPS_O) from Leuconostoc mesenteroides. EPS_O was a high-molecular-weight dextran (>6.68 × 105 g/mol) characterized by high water-holding capacity (785 ± 73%) and high water solubility index (about 99%). EPS_O in water (<30 mg/mL) formed viscous solutions, whereas at concentrations >30 mg/mL, it formed weak gels. Notably, lower concentrations (4-5 mg/mL) exhibited antimicrobial activity against various foodborne pathogens, antibiofilm activity against Listeria monocytogenes, and radical-scavenging activity. These properties are significant for maintaining food quality and promoting health. Based on these findings, EPS_O presents itself as a promising food ingredient that could elevate food quality and confer health benefits to consumers.
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Dextranos , Leuconostoc mesenteroides , Leuconostoc mesenteroides/química , Dextranos/química , Dextranos/farmacología , Listeria monocytogenes/efectos de los fármacos , Listeria monocytogenes/crecimiento & desarrollo , Peso Molecular , Solubilidad , Antibacterianos/farmacología , Antibacterianos/química , Biopelículas/efectos de los fármacosRESUMEN
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
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.
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ADN , Dextranos , Polietilenglicoles , Dextranos/química , Polietilenglicoles/química , ADN/química , Viscosidad , SolucionesRESUMEN
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.
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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
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
We investigated the binding between the c-MYC G-quadruplex (GQ) and berberine chloride (BCl) in an aqueous two-phase system (ATPS) with 12.3 wt % polyethylene glycol and 5.6 wt % dextran, mimicking the highly crowded intracellular biomolecular condensates formed via liquid-liquid phase separation. We found that in the ATPS, complex formation is significantly altered, leading to an increase in affinity and a change in the stoichiometry of the complex with respect to neat buffer conditions. Thermodynamic studies reveal that binding becomes more thermodynamically favorable in the ATPS due to entropic effects, as the strong excluded volume effect inside ATPS droplets reduces the entropic penalty associated with binding. Finally, the binding affinity of BCl for the c-MYC GQ is higher than those for other DNA structures, indicating potential specific interactions. Overall, these findings will be helpful in the design of potential drugs targeting the c-MYC GQ structures in cancer-related biocondensates.
Asunto(s)
Berberina , G-Cuádruplex , Proteínas Proto-Oncogénicas c-myc , Berberina/química , Dextranos/química , ADN/química , Polietilenglicoles/química , Proteínas Proto-Oncogénicas c-myc/química , Proteínas Proto-Oncogénicas c-myc/metabolismo , Termodinámica , Agua/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.
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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
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.
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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.
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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
The process of wound healing is intricate and complex, necessitating the intricate coordination of various cell types and bioactive molecules. Despite significant advances, challenges persist in achieving accelerated healing and minimizing scar formation. Herein, a multifunctional hydrogel engineered via dynamic Schiff base crosslinking between oxidized dextran and quaternized chitosan, reinforced with reduced graphene oxide (rGO) is reported. The resulting OQG hydrogels demonstrated injectability to aid in conforming to irregular wound geometries, rapid self-healing to maintain structural integrity and adhesion for intimate integration with wound beds. Moreover, the developed hydrogels possessed antioxidant and antibacterial activities, mitigating inflammation and preventing infection. The incorporation of conductive rGO further facilitated the transmission of endogenous electrical signals, stimulating cell migration and tissue regeneration. In addition, the polydopamine-encapsulated asiaticoside (AC@PDA) nanoparticles were encapsulated in OQG hydrogels to reduce scar formation during in vivo evaluations. In vitro results confirmed the histocompatibility of the hydrogels to promote cell migration. The recovery of the full-thickness rat wounds revealed that these designed OQG hydrogels with the incorporation of AC@PDA nanoparticles could accelerate wound healing, reduce inflammation, facilitate angiogenesis, and minimize scarring when implemented. This multifunctional hydrogel system offers a promising strategy for enhanced wound management and scarless tissue regeneration, addressing the multifaceted challenges in wound care.
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Vendajes , Quitosano , Dextranos , Grafito , Hidrogeles , Polímeros , Triterpenos , Cicatrización de Heridas , Hidrogeles/química , Hidrogeles/farmacología , Quitosano/química , Cicatrización de Heridas/efectos de los fármacos , Dextranos/química , Animales , Ratas , Triterpenos/química , Triterpenos/farmacología , Grafito/química , Polímeros/química , Ratones , Masculino , Antioxidantes/farmacología , Antioxidantes/química , Humanos , Inyecciones , Antibacterianos/farmacología , Antibacterianos/química , Ratas Sprague-Dawley , Cicatriz , IndolesRESUMEN
Subcutaneous (SC) injection is a common route of administration for drug compounds with poor oral bioavailability. However, bioavailability is often variable and incomplete, and there is as yet no standard accepted medium for simulation of the human SC environment. In this work we evaluate a FRAP based method for quantitative determination of local self-diffusion coefficients within extracellular matrix (ECM) mimetic hydrogels, potentially useful as in vitro models for drug transport in the ECM after SC injection. Gels were made consisting of either agarose, cross-linked collagen (COL) and hyaluronic acid (HA) or cross-linked HA. The diffusivities of uncharged FITC-dextran (FD4), the highly charged poly-lysine (PLK20) and poly-glutamic acid (PLE20) as well as the GLP-1 analogue exenatide were determined within the gels using FRAP. The diffusion coefficients in uncharged agarose gels were in the range of free diffusion in PBS. The diffusivity of cationic PLK20 in gels containing anionic HA was substantially decreased due to strong electrostatic interactions. Peptide aggregation could be observed as immobile fractions in experiments with exenatide. We conclude that the FRAP method provides useful information of peptides' interactions and transport properties in hydrogel networks, giving insight into the mechanisms affecting absorption of drug compounds after subcutaneous injection.
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Dextranos , Exenatida , Matriz Extracelular , Ácido Hialurónico , Hidrogeles , Péptidos , Hidrogeles/química , Difusión , Matriz Extracelular/metabolismo , Inyecciones Subcutáneas , Exenatida/farmacocinética , Exenatida/química , Exenatida/administración & dosificación , Ácido Hialurónico/química , Dextranos/química , Dextranos/farmacocinética , Péptidos/química , Péptidos/farmacocinética , Péptidos/administración & dosificación , Ácido Poliglutámico/química , Ácido Poliglutámico/análogos & derivados , Polilisina/química , Colágeno/química , Sefarosa/química , Fluoresceína-5-Isotiocianato/análogos & derivados , Fluoresceína-5-Isotiocianato/química , Fluoresceína-5-Isotiocianato/administración & dosificación , Fluoresceína-5-Isotiocianato/farmacocinética , HumanosRESUMEN
Conjugation of a therapeutic agent to a polymer for enhanced delivery into target cells followed by its intracellular triggered release has proved to be an effective drug delivery approach. This approach is applied to the delivery of the immune-stimulatory unmethylated cytosine-phosphate-guanine (CpG) oligonucleotide for an anti-tumour immune response after intratumoral administration. On average four CpG-1668 molecules were covalently linked to a 40-kDa amino-functionalised dextran polymer via either a non-reversible (CpG-dextran) or an intracellular redox-responsive disulfide linkage (CpG-SS-dextran). Dynamic light scattering analysis showed that both conjugates had a similar particle size and surface charge of 17 nm and -10 mV, respectively. Agarose gel electrophoresis analysis showed that CpG-SS-dextran was stable in the extracellular low glutathione (GSH) concentration range (i.e. 10-20 µM) and was cleaved at the higher intracellular GSH concentration (5 mM), while CpG-dextran was stable in both GSH concentrations. Uptake and activation assays on bone-marrow-derived dendritic cells showed no significant difference between free CpG, CpG-dextran and CpG-SS-dextran. In a mouse subcutaneous colorectal tumour model the CpG-SS-dextran showed a statistically significantly greater inhibition of tumour growth (p < 0.03) and prolonged survival (p < 0.001) compared to CpG-dextran or free CpG. These results demonstrate that the redox-triggered intracellular release of CpG from a dextran polymer carrier has promise for intratumoral therapeutic vaccination against cancer.
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Dextranos , Oligodesoxirribonucleótidos , Oxidación-Reducción , Dextranos/química , Dextranos/administración & dosificación , Animales , Oligodesoxirribonucleótidos/administración & dosificación , Ratones , Glutatión/metabolismo , Células Dendríticas/inmunología , Células Dendríticas/efectos de los fármacos , Femenino , Ratones Endogámicos C57BL , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/inmunología , Línea Celular Tumoral , Sistemas de Liberación de Medicamentos/métodos , Inyecciones Intralesiones , Ratones Endogámicos BALB CRESUMEN
The manufacturing of tablets containing biologics exposes the biologics to thermal and shear stresses, which are likely to induce structural changes (e.g., aggregation and denaturation), leading to the loss of their activity. Saccharides often act as stabilizers of proteins in formulations, yet their stabilizing ability throughout solid oral dosage processing, such as tableting, has been barely studied. This work aimed to investigate the effects of formulation and process (tableting and spray-drying) variables on catalase tablets containing dextran, mannitol, and trehalose as potential stabilizers. Non-spray-dried and spray-dried formulations were prepared and tableted (100, 200, and 400 MPa). The enzymatic activity, number of aggregates, reflecting protein aggregation and structure modifications were studied. A principal component analysis was performed to reveal underlying correlations. It was found that tableting and spray-drying had a notable negative effect on the activity and number of aggregates formed in catalase formulations. Overall, dextran and mannitol failed to preserve the catalase activity in any unit operation studied. On the other hand, trehalose was found to preserve the activity during spray-drying but not necessarily during tableting. The study demonstrated that formulation and process variables must be considered and optimized together to preserve the characteristics of catalase throughout processing.
Asunto(s)
Catalasa , Dextranos , Composición de Medicamentos , Excipientes , Manitol , Comprimidos , Trehalosa , Catalasa/química , Trehalosa/química , Manitol/química , Dextranos/química , Excipientes/química , Composición de Medicamentos/métodos , Química Farmacéutica/métodos , Secado por Pulverización , Agregado de ProteínasRESUMEN
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
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).