RESUMEN
Single-atom nanozymes (SAzymes) are emerging natural enzyme mimics and have attracted much attention in the biomedical field. SAzymes with MetalâNx sites designed on carbon matrixes are currently the mainstream in research. It is of great significance to further expand the types of SAzymes to enrich the nanozyme library. Single-atom alloys (SAAs) are a material in which single-atom metal sites are dispersed onto another active metal matrix, and currently, there is limited research on their enzyme-like catalytic performance. In this work, a biodegradable Pt1Pd SAA is fabricated via a simple galvanic replacement strategy, and for the first time reveals its intrinsic enzyme-like catalytic performance including catalase-, oxidase-, and peroxidase-like activities, as well as its photodynamic effect. Experimental characterizations demonstrate that the introduction of single-atom Pt sites contributes to enhancing the affinity of Pt1Pd single-atom alloy nanozyme (SAAzyme) toward substrates, thus exhibiting boosted catalytic efficiency. In vitro and in vivo experiments demonstrate that Pt1Pd SAAzyme exhibits a photo-controlled therapeutic effect, with a tumor inhibition rate of up to 100%. This work provides vital guidance for opening the research direction of SAAs in enzyme-like catalysis.
Asunto(s)
Aleaciones , Aleaciones/química , Animales , Platino (Metal)/química , Humanos , Catálisis , Neoplasias/terapia , Neoplasias/tratamiento farmacológico , Ratones , Fototerapia/métodosRESUMEN
Oral ulcers present as recurrent and spontaneous lesions, often causing intolerable burning pain that significantly disrupts patients' daily lives and compromises their quality of life. In addressing this clinical challenge, oral dissolving films (ODFs) have emerged as promising pharmaceutical formulations for oral ulcer management due to their rapid onset of action, ease of administration, and portability. In this study, ODFs containing the insoluble drug dexamethasone (Dex) were formulated for the treatment of oral ulcers in rabbits using a solvent casting method with ethanol as the solvent. To optimize the composition of the ODFs, a Box-Behnken Design (BBD) experiment was employed to investigate the effects of varying concentrations of hydroxypropyl cellulose (HPC), low-substituted hydroxypropyl cellulose (L-HPC), and plasticizer (glycerol) on key parameters, such as disintegration time, tensile strength, and peel-off efficiency of the films. Subsequently, the film properties of the Dex-loaded ODFs (ODF@Dex) were thoroughly assessed, revealing favorable attributes, including homogeneity, mechanical strength, and solubility. Notably, the use of ethanol as the solvent in the ODF preparation facilitated the homogeneous distribution of insoluble drugs within the film matrix, thereby enhancing their solubility and dissolution rate. Leveraging the potent pharmacological activity of Dex, ODF@Dex was further evaluated for its efficacy in promoting ulcer healing and mitigating the expression of inflammatory factors both in vitro and in vivo. The findings demonstrated that the ODF@Dex exerted significant antiulcer effects by modulating the PI3K/Akt signaling pathway, thus contributing to ulcer resolution. In conclusion, our study underscores the potential of HPC-based ODFs formulated with ethanol as a solvent as a promising platform for delivering insoluble drugs, offering a viable strategy for the clinical management of oral ulcers.
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Celulosa , Dexametasona , Úlceras Bucales , Solubilidad , Dexametasona/química , Dexametasona/administración & dosificación , Celulosa/análogos & derivados , Celulosa/química , Conejos , Animales , Úlceras Bucales/tratamiento farmacológico , Administración Oral , Masculino , Resistencia a la Tracción , Liberación de Fármacos , Etanol/química , Etanol/administración & dosificación , Composición de Medicamentos/métodosRESUMEN
The capillarization of hepatic sinusoids resulting from the activation of hepatic stellate cells poses a significant challenge, impeding the effective delivery of therapeutic agents to the Disse space for liver fibrosis treatment. Therefore, overcoming these barriers and achieving efficient drug delivery to activated hepatic stellate cells (aHSCs) are pressing challenge. In this study, we developed a synergistic sequential drug delivery approach utilizing neutrophil membrane hybrid liposome@atorvastatin/amlisentan (NCM@AtAm) and vitamin A-neutrophil membrane hybrid liposome @albumin (VNCM@Bai) nanoparticles (NPs) to breach the capillary barrier for targeted HSC cell delivery. Initially, NCM@AtAm NPs were successfully directed to the site of hepatic fibrosis through neutrophil-mediated inflammatory targeting, resulting in the normalization of liver sinusoidal endothelial cells (LSECs) and restoration of fenestrations under the combined influence of At and Am. Elevated tissue levels of the p-Akt protein and endothelial nitric oxide synthase (eNOS) indicated the normalization of LSECs following treatment with At and Am. Subsequently, VNCM@Bai NPs traversed the restored LSEC fenestrations to access the Disse space, facilitating the delivery of Bai into aHSCs under vitamin A guidance. Lastly, both in vitro and in vivo results demonstrated the efficacy of Bai in inhibiting HSC cell activation by modulating the PPAR γ/TGF-ß1 and STAT1/Smad7 signaling pathways, thereby effectively treating liver fibrosis. Overall, our designed synergistic sequential delivery system effectively overcomes the barrier imposed by LSECs, offering a promising therapeutic strategy for liver fibrosis treatment in clinical settings.
Asunto(s)
Células Endoteliales , Células Estrelladas Hepáticas , Humanos , Células Endoteliales/metabolismo , Biónica , Capilares/metabolismo , Liposomas/metabolismo , Neutrófilos/metabolismo , Vitamina A/metabolismo , Vitamina A/farmacología , Hígado/metabolismo , Cirrosis Hepática/tratamiento farmacológico , Cirrosis Hepática/metabolismoRESUMEN
OBJECTIVES: To evaluate the effect of hyperlipidemia on the healing of bone defects. MATERIALS AND METHODS: Apolipoprotein E (ApoE)-deficient mice and wild-type (WT) C57BL/6J mice were fed with an atherogenic high-fat diet (HFD) or a standard chow diet (as control) for 6 weeks. Blood samples were collected to evaluate serum lipid levels. Closed bone defects and open tooth extraction wounds were then created in the mandibles of these animals. One or two weeks after surgery, animals were euthanized. Micro-CT analysis and histomorphometric analysis were conducted to evaluate the healing of bone defects and the alveolar ridge resorption. RESULTS: Bone regeneration of closed bone defects was considerably delayed in the hyperlipidemic Apoe-/- mice and WT mice. No obvious difference was detected in the new bone formation of the tooth extraction wounds. The HFD-fed mice showed more prominent reduction in the lingual alveolar ridge height of the tooth extraction wounds when compared with the control group. CONCLUSIONS: Hyperlipidemia results in delayed bone regeneration in large closed bone defects. Although tooth extraction wounds are small and normally regenerated in a hyperlipidemic microenvironment, the prominent reduction in the alveolar ridge height is also a challenge for future restoration of the dentition.
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Pérdida de Hueso Alveolar , Aumento de la Cresta Alveolar , Hiperlipidemias , Animales , Ratones , Alveolo Dental/cirugía , Hiperlipidemias/complicaciones , Aumento de la Cresta Alveolar/métodos , Ratones Endogámicos C57BL , Ratones Noqueados para ApoE , Regeneración Ósea , Pérdida de Hueso Alveolar/cirugía , Extracción Dental/métodos , Apolipoproteínas ERESUMEN
Microplastic pollution is an emerging threat for marine and terrestrial ecosystems, which has raised global concerns about its implications for human health. Mounting evidence has shown that the gut microbiota plays a key role in human health and diseases. The gut bacteria could be disturbed by many environmental factors, including the microplastic particles. However, the size effect of polystyrene microplastics on mycobiome, as well as gut functional metagenome has not been well studied. In this study, we performed ITS sequencing to explore the size effect of polystyrene microplastics on the fungal composition, in combination with the shotgun metagenomics sequencing to reveal the size effects of polystyrene on the functional metagenome. We found that polystyrene microplastic particles with 0.05-0.1 µm diameter showed greater impact on the bacterial and fungal composition of gut microbiota as well as the metabolic pathways than the polystyrene microplastic particles with 9-10 µm diameter. Our results suggested that size-depended effects should not be ignored in the health risk assessment of microplastics.
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Poliestirenos , Contaminantes Químicos del Agua , Humanos , Animales , Ratones , Poliestirenos/toxicidad , Poliestirenos/análisis , Microplásticos/toxicidad , Plásticos , Metagenoma , Ecosistema , Ratones Endogámicos C57BL , Farmacorresistencia Microbiana , Contaminantes Químicos del Agua/toxicidad , Contaminantes Químicos del Agua/análisisRESUMEN
This study aimed to describe the application of transferring preexpanded forehead flaps based on the supratrochlear and supraorbital arteries in 3 patterns for facial reconstruction: Pattern I, interpolated flap; Pattern II, island flap; and Pattern III, propeller flap, which was subdivided into direct propeller flap (Pattern IIIa) and indirect propeller flap (Pattern IIIb). During the first stage, a tissue expander was inserted underneath the forehead. After sufficient inflation of the expander, a forehead flap based on the supratrochlear or supraorbital artery was elevated and transferred to reconstruct the facial defects. Three weeks after the surgery, pedicle division was performed, in which Pattern I and Pattern IIIb flaps were used. Twenty-four patients underwent facial reconstruction. Twenty-three flaps survived without any perfusion-related complications. Venous congestion developed in an island flap. All patients were followed up after surgery, ranging from 2 to 156 (mean, 19) months. The color and texture of the flap matched those of the adjacent skin. The patients and their families were satisfied with the final functional and esthetic outcomes. The forehead flap based on the supratrochlear and supraorbital arteries provides reliable coverage of facial defects. The conventional interpolated flap continues to be the most dependable. Single-stage reconstruction using the island flap and direct propeller flap is applicable to patients who decline the pedicle division procedure. The novel technique of using the indirect propeller flap is safe for cheek reconstruction with minimal donor-site morbidity and esthetically pleasing results.
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Procedimientos de Cirugía Plástica , Humanos , Frente/cirugía , Frente/irrigación sanguínea , Estética Dental , Colgajos Quirúrgicos/cirugía , Trasplante de Piel/métodos , Arteria OftálmicaRESUMEN
BACKGROUND: This research aims to quantify pro-inflammatory cytokines from the exudates of dental pulp tissues are helpful in the diagnosis of pulpitis, thus, laying down the foundation for further vital pulp therapy on irreversible pulpitis. METHODS: The authors selected patients admitted to Beijing Stomatological Hospital from October 2016 to March 2018. Exudates were collected from pulp exposure and were divided into four groups, which encompass normal pulps (Group 1), early stage of chronic pulpitis (Group 2), late stage of chronic pulpitis (Group 3) and acute attack of chronic pulpitis (Group 4). RESULTS: The cytokines IL-1ß, IL-6, IL-8 and TNF from the exudates of dental pulp tissues were quantified by cytometric bead array using enhanced sensitivity flex sets. All statistical analyses were performed using SPSS 22.0 and the 2-sided significance level was set at p < 0.05. The Kruskal-Wallis test, Mann-Whitney U test and Spearman correlation analysis were employed to process data. CONCLUSION: There were 32, 37, 14, 29 samples in Groups 1, 2, 3 and 4, respectively. Only small amount of IL-1ß, IL-8 was expressed in normal pulps and almost no TNF, IL-6 could be detected in Group 1. No difference was observed in the concentration of TNF between Group 2, 3, 4.
Asunto(s)
Citocinas , Pulpitis , Pulpa Dental , Exudados y Transudados , Humanos , Interleucina-6 , Interleucina-8RESUMEN
ABSTRACT: En bloc reconstruction of extensive head and neck defects is feasible with matched tissue from the medial arm or chest. Nevertheless, the donor site faces significant morbidity following massive cutaneous flap harvesting. The serial flap transfer technique can increase the reconstructive ability of these flaps and minimize the donor site morbidity. A retrospective review was conducted from 2016 to 2020 on all patients who had undergone extensive head and neck reconstruction with the serial flap transfer technique. En bloc reconstruction of defects in the head and neck was performed using expanded perforator-plus flaps from the medial arm or chest; various flaps from the back were used to close the donor-site defects. Flap type, flap survival, complications, and revision procedures were assessed. This case series included 16 patients. The donor site of the chest or medial arm was successfully closed with the assistance of the thoracodorsal artery perforator flap, the latissimus dorsi myocutaneous flap, ortheparascapular flap. A medial arm flap with a width of 15âcm and a chest flap with a 16âcm width could be transferred with the primary closure of the donor sites. All flaps survived, except 1 had marginal necrosis. Complications occurred in 2 patients and were successfully managed nonsurgically. Both the recipient and donor sites were restored with good aesthetic results. Application of the serial flap transfer technique in extensive head and neck reconstruction decreases the donor site morbidity to a minimum and improves the overall outcomes.
Asunto(s)
Mamoplastia , Colgajo Perforante , Procedimientos de Cirugía Plástica , Traumatismos de los Tejidos Blandos , Estética Dental , Humanos , Cuello/cirugía , Colgajo Perforante/irrigación sanguínea , Procedimientos de Cirugía Plástica/métodosRESUMEN
Twinning is a common deformation mechanism in metals, and twin boundary (TB) segregation of impurities/solutes plays an important role in the performances of alloys such as thermostability, mobility, and even strengthening. The occurrence of such segregation phenomena is generally believed as a one-layer coverage of solutes alternately distributed at extension/compression sites, in an orderly, continuous manner. However, in the Mn-free and Mn-containing Mg-Nd model systems, we reported unexpected three- and five-layered discontinuous segregation patterns of the coherent {101Ì 1} TBs, and not all the extension sites occupied by solutes larger in size than Mg, and even some larger sized solutes taking the compression sites. Nd/Mn solutes selectively segregate at substitutional sites and thus to generate two new types of ordered two-dimensional TB superstructures or complexions. These findings refresh the understanding of solute segregation in the perfect coherent TBs and provide a meaningful theoretical guidance for designing materials via targeted TB segregation.
Asunto(s)
Aleaciones , Aleaciones/químicaRESUMEN
Polymalic acid (PMA), a homopolymer of L-malic acid (MA) generated from a yeast-like fungus Aureobasidium pullulans, has unique properties and many applications in food, biomedical, and environmental fields. Acid hydrolysis of PMA, releasing the monomer MA, has become a novel process for the production of bio-based MA, which currently is produced by chemical synthesis using petroleum-derived feedstocks. Recently, current researches attempted to develop economically competitive process for PMA and MA production from renewable biomass feedstocks. Compared to lignocellulosic biomass, PMA and MA production from low-value food processing wastes or by-products, generated from corn, sugarcane, or soybean refinery industries, showed more economical and sustainable for developing a MA derivatives platform from biomass biorefinery to chemical conversion. In the review, we compared the process feasibility for PMA fermentation with lignocellulosic biomass and food process wastes. Some useful strategies for metabolic engineering are summarized. Its changeable applicability and future prospects in food and biomedical fields are also discussed.
Asunto(s)
Ascomicetos , Ascomicetos/metabolismo , Biomasa , Fermentación , Manipulación de Alimentos , Malatos , Polímeros/metabolismoRESUMEN
Various polydopamine (PDA) nanospheres were synthesized by utilizing triblock copolymer Pluronic F127 and 1,3,5-trimethylbenzene (TMB) as soft templates. Precise morphology control of polydopamine nanospheres was realized from solid polydopamine nanospheres to hollow polydopamine nanospheres, mesoporous polydopamine nanospheres and hollow mesoporous polydopamine nanospheres (H-MPDANSs) by adjusting the weight ratio of TMB to F127. The inner diameter of the prepared H-MPDANSs can be controlled in the range of 50-100 nm, and the outer diameter is about 180 nm. Furthermore, the thickness of hollow mesoporous spherical shell can be adjusted by changing the amount of dopamine (DA). The H-MPDANSs have good biocompatibility, excellent photothermal properties, high drug loading capacity, and outstanding sustainable drug release properties. In addition, both NIR laser irradiation and acid pH can facilitate the controlled release of doxorubicin (DOX) from H-MPDANSs@DOX.
Asunto(s)
Materiales Biocompatibles/química , Portadores de Fármacos/química , Indoles/química , Nanosferas/química , Polímeros/química , Materiales Biocompatibles/síntesis química , Materiales Biocompatibles/farmacología , Supervivencia Celular/efectos de los fármacos , Doxorrubicina/química , Doxorrubicina/metabolismo , Portadores de Fármacos/síntesis química , Portadores de Fármacos/toxicidad , Liberación de Fármacos , Sinergismo Farmacológico , Eritrocitos/citología , Eritrocitos/efectos de los fármacos , Eritrocitos/metabolismo , Células HeLa , Hemólisis/efectos de los fármacos , Humanos , Microscopía Electrónica de Transmisión , Tamaño de la Partícula , Poloxámero/química , PorosidadRESUMEN
Cyclic-poly(phthalaldehyde) (cPPHA) exhibits photo-triggerable depolymerization on-demand for applications like the photolithography of microfabricated electronics. However, cPPHA is inherently brittle and thermally sensitive; both of these properties limit its usefulness as an engineering plastic. Prior to this report, small molecule plasticizers are added to cPPHA-based films to make the polymer more flexible. But plasticizers can eventually leach out of cPPHA, then leaving it increasingly more brittle throughout product lifetime. In this research, a new approach to fabricating flexible cPPHA blends for use as spun fibers is achieved through the incorporation of poly (ε-caprolactone) (PCL) by a modified wet spinning method. Among blend compositions, the 50/50 cPPHA/PCL fiber shows fast transience (<50 s) in response to daylight while retaining the flexibility of PCL and mechanical properties of an elastomer (i.e., tensile strength of ≈8 MPa, Young's modulus of ≈118 MPa, and elongation at break of ≈190%). Embedding 2 wt% gold nanoparticles to cPPHA can further improve the transience rate of fibers comprising less than 50% cPPHA. These flexible, daylight-triggerable cPPHA/PCL fibers can be applied to an extensive range of applications, such as wearable electronics, intelligent textiles, and zero waste packaging for which modest mechanical performance and fast transience are desired.
Asunto(s)
Materiales Biocompatibles , Nanopartículas del Metal , Oro , PoliésteresRESUMEN
A novel magnetic organic porous polymer (denoted as Fe3O4@PC-POP) was developed for magnetic solid-phase extraction (MSPE) of two gastric cancer biomarkers (P-cresol and 4-hydroxybenzoic acid) from urine samples prior to high-performance liquid chromatographic analysis. The adsorbent was characterized by scanning electron microscope, transmission electron microscope, FTIR, powder X-ray diffraction, and other techniques. The result of dynamic light scattering shows that the particle size of the adsorbent is mainly distributed around 400 nm. Based on the design concept of the Fe3O4@PC-POP, the proposed material can effectively capture the target analytes through electrostatic and hydrophobic interaction mechanism. Furthermore, the enrichment conditions were optimized by the response surface method, and the method was utilized for the determination of P-cresol and 4-hydroxybenzoic acid in real urine samples from health and gastric cancer patients with high enrichment factors (34.8 times for P-cresol and 38.7 times for 4-hydroxybenzoic acid), low limit of detection (0.9-5.0 µg L-1), wide linear ranges (3.0-1000 µg L-1), satisfactory relative standard deviation (2.5%-8.5%), and apparent recoveries (85.3-112% for healthy people's and 86.0-112% for gastric cancer patients' urine samples). This study provides a guided principle for design of the versatile polymer with specific capturing of the target compounds from complex biological samples. Graphical abstract.
Asunto(s)
Biomarcadores de Tumor/orina , Cresoles/orina , Nanopartículas de Magnetita/química , Parabenos/análisis , Polímeros/química , Neoplasias Gástricas/orina , Adsorción , Biomarcadores de Tumor/química , Biomarcadores de Tumor/aislamiento & purificación , Cromatografía Líquida de Alta Presión , Cresoles/química , Cresoles/aislamiento & purificación , Humanos , Límite de Detección , Parabenos/química , Parabenos/aislamiento & purificación , Piperazinas/química , Porosidad , Extracción en Fase Sólida/métodosRESUMEN
In this study, a novel nitrogen-rich hyperbranched polymer was designed and synthesized via one-step precipitation copolymerization strategy. As possessing the lone-pair-electron-containing nitrogen atoms and positive-charged amine groups, as well as π electron-conjugated system, the prepared polymer displayed a strong tendency to adsorb protons acid, and negative-charged and conjugated compounds according to acid-base interaction, electrostatic interaction, and π-π stacking interaction. Based on these properties, a novel approach for assembling the proposed polymer coupled with high-performance liquid chromatography was successfully employed for selective enrichment and determination of auxins in plants. The extraction and desorption conditions were evaluated and the limits of detection and the limits of quantification of the proposed method were in the range of 0.15-0.29 µg L-1 and 0.49-0.98 µg L-1 for the four auxins based on the signal-to-noise ratio of 3:1 and 10:1, respectively. The recoveries of the target auxins from spiked plant samples were in the range from 85.0 to 116.3% with relative standard deviations lower than 9.6%. This study presented an inspiring thought for the construction of the versatile polymer adsorbent with highly efficient capturing of analytes from complex samples. Graphical abstract.
Asunto(s)
Cromatografía Líquida de Alta Presión/métodos , Ácidos Indolacéticos/análisis , Nitrógeno/química , Plantas/química , Polímeros/química , Extracción en Fase Sólida/métodos , Adsorción , Ácidos Indolacéticos/aislamiento & purificación , Límite de Detección , Concentración OsmolarRESUMEN
Phenol, as a representative organic pollutant in aquatic environments, has posed a serious threat to humans and ecosystem. In this work, a novel integration system combined coal-based carbon membrane with sulfate radicals-based advanced oxidation processes (SR-AOPs) was designed for degradation of phenol. The integrated system achieved 100% removal efficiency under the optimal condition (peroxydisulfate dosage is 0.2â¯g/L, at alkaline condition with 2â¯mL/min flow velocity). The quenching experiments revealed that the efficient removal of phenol by the integrated system were attributed to the co-existence of radical and nonradical mechanisms. This study proposes a green and efficient technique for the removal of phenol.
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Carbono/química , Membranas Artificiales , Fenol/análisis , Sulfatos/química , Contaminantes Químicos del Agua/análisis , Purificación del Agua/métodos , Carbón Mineral , Ecosistema , Modelos Teóricos , Oxidación-Reducción , Aguas Residuales/químicaRESUMEN
Polyacrylonitrile fibers with and without magnetic nanoparticles (Fe3O4 NPs) were prepared by electrospinning. The pure polyacrylonitrile (PAN) fibers and the composited polyacrylonitrile (PAN/Fe3O4) fibers were studied with respect to their capability for enrichment of glycoproteins. Specifically, the glycoproteins ovalbumin (OB) and transferrin (Trf) were studied and compared to the non-glycoproteins bovine serum albumin and lysozyme. Following adsorption and subsequent protein elution with 0.1 wt% of CTAB solution, the glycoproteins were analyzed by SDS polyacrylamide gel electrophoresis. The strong interaction between PAN or PAN/Fe3O4 fibers and glycoproteins is attributed to the synergistic effects of hydrophilic and hydrogen bond interactions. The PAN/Fe3O4 fibers have an attractive additional feature of allowing magnetic separation. The PAN and PAN/Fe3O4 fibers have a high adsorption capacity toward OB and Trf. The treated PAN/Fe3O4 fibers display good selectivity, fast adsorption kinetics, and were applied to extractions of mixed protein samples. The detection limits of OB and Trf are 0.32 and 0.22 µg·mL-1, respectively. The PAN/Fe3O4 fibers offered an alternative solution for adsorption of glycoproteins from biological samples. Graphical abstract The pure polyacrylonitrile (PAN) fibers and the composited polyacrylonitrile (PAN/Fe3O4) fibers were studied with respect to their capability for enrichment of glycoproteins: glycoproteins ovalbumin (OB) and transferrin (Trf). The treated PAN/Fe3O4 fibers showed fast adsorption kinetics, were applied in a physiological state, mixed and real samples.
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Resinas Acrílicas/química , Glicoproteínas/química , Nanopartículas de Magnetita/química , Ovalbúmina/química , Transferrina/química , Adsorción , Muramidasa/química , Albúmina Sérica Bovina/químicaRESUMEN
To explore and utilize the advantages of droplet-based microfluidics, hydrodynamics, and mixing process within droplets traveling though the T junction channel and convergent-divergent sinusoidal microchannels are studied by numerical simulations and experiments, respectively. In the T junction channel, the mixing efficiency is significantly influenced by the twirling effect, which controls the initial distributions of the mixture during the droplet formation stage. Therefore, the internal recirculating flow can create a convection mechanism, thus improving mixing. The twirling effect is noticeably influenced by the velocity of the continuous phase; in the sinusoidal channel, the Dean vortices and droplet deformation are induced by centrifugal force and alternative velocity gradient, thus enhancing the mixing efficiency. The best mixing occurred when the droplet size is comparable with the channel width. Finally, we propose a unique optimized structure, which includes a T junction inlet joined to a sinusoidal channel. In this structure, the mixing of fluids in the droplets follows two routes: One is the twirling effect and symmetric recirculation flow in the straight channel. The other is the asymmetric recirculation and droplet deformation in the winding and variable cross-section. Among the three structures, the optimized structure has the best mixing efficiency at the shortest mixing time (0.25 ms). The combination of the twirling effect, variable cross-section effect, and Dean vortices greatly intensifies the chaotic flow. This study provides the insight of the mixing process and may benefit the design and operations of droplet-based microfluidics.
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Técnicas Analíticas Microfluídicas/métodos , Dimetilpolisiloxanos/química , Diseño de Equipo/instrumentación , Hidrodinámica , Dispositivos Laboratorio en un Chip , Técnicas Analíticas Microfluídicas/instrumentación , Modelos Químicos , Tamaño de la Partícula , Reología , Soluciones , Propiedades de Superficie , Factores de TiempoRESUMEN
It is a great challenge to design a drug delivery system with a controlled manner, especially one triggered by an exclusive endogenous disease marker and with an easily tracked release process. Herein, we developed a drug delivery platform of carbon dots which were connected to a stem-loop molecular beacon loaded with doxorubicin and polyethylene glycol modified folic acid. Such a platform enables one to release drugs on demand under the stimuli of endogenous microRNA-21, and turn on the fluorescence of carbon dots and doxorubicin, which allows one to monitor the drug release process. The intracellular experiment indicated that folic acid could mediate endocytosis of the nanocarrier, and the overexpressed endogenous microRNA-21 served as a unique key to unlock the drug nanocarrier by competitive hybridization with the molecular beacon, which finally resulted in fluorescence recovery and realized a chemotherapeutic effect within human breast cancer cells. The nanocarrier may have potential application in personalized treatment of different cancer subtypes in which the corresponding miRNAs are overexpressed.
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Doxorrubicina/metabolismo , Portadores de Fármacos/química , MicroARNs/química , Microscopía Confocal , Supervivencia Celular/efectos de los fármacos , Doxorrubicina/química , Portadores de Fármacos/toxicidad , Liberación de Fármacos , Endocitosis , Citometría de Flujo , Transferencia Resonante de Energía de Fluorescencia , Ácido Fólico/química , Humanos , Células MCF-7 , Polietilenglicoles/química , Puntos Cuánticos/química , TemperaturaRESUMEN
Solid-state amorphization of crystalline rebamipide (RBM) was realized by ball milling and spray drying. The amorphous content of samples milled for various time was quantified using X-ray powder diffraction. Crystalline RBM and three amorphous RBM obtained by milling and spray drying were characterized by morphological analysis, X-ray diffraction, thermal analysis and vibrational spectroscopy. The crystal structure of RBM was first determined by single-crystal X-ray diffraction. In addition, the solubility and dissolution rate of the RBM samples were investigated in different media. Results indicated that the solubility and the dissolution rates of spray-dried RBM-PVP in different media were highly improved compared with crystalline RBM. The physical stabilities of the three amorphous RBM were systematically investigated, and the stability orders under different storage temperatures and levels of relative humidity (RH) were both as follows: spray dried RBM < milled RBM < spray dried RBM-PVP. A direct glass-to-crystal transformation was induced under high RH, and the transformation rate rose with increasing RH. However, amorphous RBM could stay stable at RH levels lower than 57.6% (25 °C).
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Alanina/análogos & derivados , Povidona/química , Quinolonas/química , Difracción de Rayos X , Alanina/química , Rastreo Diferencial de Calorimetría , Desecación , Estabilidad de Medicamentos , Polvos , Solubilidad , Ondas UltrasónicasRESUMEN
Second near-infrared (NIR-II) mild photothermal therapy with higher tissue penetration depth and less damage to healthy tissues is emerging as an attractive antitumor modality, but its therapeutic efficiency is dramatically suppressed by the resistance of heat shock proteins (HSPs). As a widely explored photothermal agent, the application of polydopamine (PDA) in the NIR-II region is hampered by low photothermal conversion efficiency (PCE). Herein, its PCE in the NIR-II region is improved by developing novel hollow cavity CaO2 @PDA nanocomposites through chelation-induced diffusion of inner core Ca2+ to the shell PDA to facilitate multiple reflections of laser in the cavity. Upon pH-responsive degradation of CaO2 , its structure is transformed into a stacked "nano-mesh" with excellent light absorption and an enlarged effective irradiation area. Overloading of Ca2+ ions not only induces downregulation of HSPs but also enhances interference of light on membrane potential, which further aggravate mitochondrial dysfunction and reduce the thermotolerance of tumor cells, promoting efficient mild hyperthermia of PDA in the NIR-II region.