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1.
J Colloid Interface Sci ; 661: 123-138, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38295695

RESUMEN

Most cases of delayed wound healing are associated with bacterial biofilm infections due to high antibiotic resistance. To improve patient compliance and recovery rates, it is critical to develop minimally invasive and efficient methods to eliminate bacterial biofilms as an alternative to clinical debridement techniques. Herein, we develop a dissolving microneedle system containing Ag nanoparticles (AgNPs)-decorated silk fibroin microspheres (SFM-AgNPs) and antibiotics for synergistic treatment of bacterial biofilm infection. Silk fibroin microspheres (SFM) are controllably prepared in an incompatible system formed by a mixture of protein and carbohydrate solutions by using a mild all-aqueous phase method and serve as biological templates for the synthesis of AgNPs. The SFM-AgNPs exert dose- and time-dependent broad-spectrum antibacterial effects by inducing bacterial adhesion. The combination of SFM-AgNPs with antibiotics breaks the limitation of the antibacterial spectrum and achieves better efficacy with reduced antibiotic dosage. Using hyaluronic acid (HA) as the soluble matrix, the microneedle system containing SFM-AgNPs and anti-Gram-positive coccus drug (Mupirocin) inserts into the bacterial biofilms with sufficient strength, thereby effectively delivering the antibacterial agents and realizing good antibiofilm effect on Staphylococcus aureus-infected wounds. This work demonstrates the great potential for the development of novel therapeutic systems for eradicating bacterial biofilm infections.


Asunto(s)
Fibroínas , Nanopartículas del Metal , Infecciones Estafilocócicas , Humanos , Antibacterianos/farmacología , Fibroínas/farmacología , Plata/farmacología , Microesferas , Bacterias , Biopelículas , Seda
2.
Nano Lett ; 23(20): 9657-9663, 2023 Oct 25.
Artículo en Inglés | MEDLINE | ID: mdl-37548909

RESUMEN

Structural colors show diverse advantages such as fade resistance, eco-friendliness, iridescence, and high saturation in comparison with chemical pigments. In this paper, we show tunable structural coloration in colorless water-in-oil-in-water double emulsion droplets via total internal reflection and interference at the microscale concave interfaces. Through experimental work and simulations, we demonstrate that the shell thickness and the eccentricity of the core-shell structures are key to the successful formation of iridescent structural colors. Only eccentric thin-shell water-in-oil-in-water droplets show structural colors. Importantly, structural colors based on water-oil interfaces are readily responsive to a variety of environmental stimuli, such as osmotic pressure, temperature, magnetic fields, and light composition. This work highlights an alternative structural coloration that expands the applications of droplet-based structural colors to aqueous systems.

3.
Adv Healthc Mater ; 12(21): e2300873, 2023 08.
Artículo en Inglés | MEDLINE | ID: mdl-37265189

RESUMEN

Transcatheter arterial radioembolization (TARE) is of great significance for the treatment of advanced hepatocellular carcinoma (HCC). However, the existing radioembolic microspheres still have problems such as non-degradability, non-uniform size, and inability to directly monitor in vivo, which hinders the development of TARE. In this paper, a novel radioembolic agent, 131 I-labeled methacrylated gelatin microspheres (131 I-GMs), is prepared for the treatment of HCC. Water-in-oil (W/O) emulsion templates are prepared by a simple one-step microfluidic method to obtain methacrylated gelatin microspheres (GMs) after UV irradiation. A series of GMs with uniform and controllable size is obtained by adjusting the flow rate of each fluid. Both air-dried and freeze-dried GMs can quickly restore their original shape and size, and still have good monodispersity, elasticity, and biocompatibility. The radiolabeling experiments show that 131 I can efficiently bind to GMs by chloramine-T method, and the obtained 131 I-GMs have good radioactive stability in vitro. The results of in vivo TARE treatment in rats show that 131 I-GMs can be well retained in the hepatic artery and have a good inhibitory effect on the progression of liver cancer, showing the potential for the treatment of HCC.


Asunto(s)
Carcinoma Hepatocelular , Neoplasias Hepáticas , Ratas , Animales , Neoplasias Hepáticas/radioterapia , Neoplasias Hepáticas/patología , Carcinoma Hepatocelular/radioterapia , Microesferas , Gelatina , Microfluídica
4.
J Hazard Mater ; 445: 130610, 2023 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-37056001

RESUMEN

The development of materials with highly selective recognition towards Hg2+ is of great significance in environmental monitoring. Herein, a novel thermo-responsive copolymer with Hg2+ recognition property is prepared via thermally-initiated copolymerization of 5'-O-Acryloyl 5-methyl-uridine (APU) and N-isopropylacrylamide (NIPAM). The chemical structure and stimuli-sensitive properties of poly(N-isopropylacrylamide-co-5-methyl-uridine) (P(NIPAM-co-APU)) linear polymers and hydrogel are thoroughly investigated. At the supramolecular level, P(NIPAM-co-APU) linear polymers could respond to both temperature and Hg2+ stimuli with highly selective recognition towards Hg2+ over other 18 metal ion species (at least 5 fold difference) and common anions. Upon capturing Hg2+ by APU units as host metal receptors, the lower critical solution temperature (LCST) of P(NIPAM-co-APU, PNU-7 and PNU-11) linear polymers are significantly shifted more than 10 °C due to the formation of stable APU-Hg2+-APU directed host-guest complexes. Accordingly, at the macroscopic level, P(NIPAM-co-APU) hydrogel display selective and robust recognition of Hg2+ under optimum conditions, and its maximum Hg2+ uptake capacity was 33.1 mg g-1. This work provides a new option for Hg2+ recognition with high selectivity, which could be facilely integrated with other smart systems to achieve satisfactory detection of environmental Hg2+.

5.
Small ; 19(34): e2300801, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37072877

RESUMEN

Sub-10 nm nanoparticles are known to exhibit extraordinary size-dependent properties for wide applications. Many approaches have been developed for synthesizing sub-10 nm inorganic nanoparticles, but the fabrication of sub-10 nm polymeric nanoparticles is still challenging. Here, a scalable, spontaneous confined nanoemulsification strategy that produces uniform sub-10 nm nanodroplets for template synthesis of sub-10 nm polymeric nanoparticles is proposed. This strategy introduces a high-concentration interfacial reaction to create overpopulated surfactants that are insoluble at the droplet surface. These overpopulated surfactants act as barriers, resulting in highly accumulated surfactants inside the droplet via a confined reaction. These surfactants exhibit significantly changed packing geometry, solubility, and interfacial activity to enhance the molecular-level impact on interfacial instability for creating sub-10 nm nanoemulsions via self-burst nanoemulsification. Using the nanodroplets as templates, the fabrication of uniform sub-10 nm polymeric nanoparticles, as small as 3.5 nm, made from biocompatible polymers and capable of efficient drug encapsulation is demonstrated. This work opens up brand-new opportunities to easily create sub-10 nm nanoemulsions and advanced ultrasmall functional nanoparticles.

6.
J Hazard Mater ; 443(Pt B): 130289, 2023 02 05.
Artículo en Inglés | MEDLINE | ID: mdl-36345059

RESUMEN

Ultrasensitive real-time detection of trace Pb2+ in continuous flow is vital to effectively and timely eliminate the potential hazards to ecosystem health and sustainability. This work reports on a micro-structured smart hydrogel grating with ultra-sensitivity, high selectivity, good transparency and mechanical property for real-time detection of Pb2+ in continuous flow. The hydrogel grating possesses uniform surface relief microstructures with periodic nano-height ridges made of poly(acrylamide-co-benzo-18-crown-6-acrylamide) networks that crosslinked by tetra-arm star poly(ethylene glycol)acrylamide. The hydrogel grating with good optical transparency and mechanical property can change its height via selective host-guest complexation with Pb2+ to output a changed diffraction efficiency. Meanwhile, the periodic nano-ridges with large specific area benefit the contact with Pb2+ for fast Pb2+-induced height change. Thus, with such rationally designed molecular structures and surface relief microstructures, the hydrogel grating integrated in a glass-based mini-chip allows real-time detection of Pb2+ in continuous flow with ultra-sensitivity and high selectivity. The hydrogel grating detector can achieve ultralow detection limit (10-9 M Pb2+), fast response (2 min), and selective detection of Pb2+ from dozens of interfering ions even with high concentrations. This high-performance hydrogel grating detector is general and can be extended to detect many analytes due to the wide choice of responsive hydrogels, thus opening new areas for creating advanced smart detectors in analytical science.


Asunto(s)
Hidrogeles , Plomo , Hidrogeles/química , Ecosistema , Iones/química , Acrilamida
7.
ACS Appl Mater Interfaces ; 15(1): 638-650, 2023 Jan 11.
Artículo en Inglés | MEDLINE | ID: mdl-36576723

RESUMEN

A composite separable microneedles (MNs) system consisting of silk fibroin (SF) needle tips and hyaluronic acid (HA) base is developed for transdermal delivery of salmon calcitonin (sCT) for therapy of osteoporosis. Poly(ethylene glycol) (PEG) is used to modulate the conformation structure of SF to achieve controllable sustained release of sCT. The prepared MNs can effectively penetrate the skin stratum corneum. After application to the skin, the HA base is dissolved within 2 min, allowing these SF drug depots to be implanted into the skin for controllable sustained release of sCT. The release kinetics of sCT can be controlled by regulating the conformation of SF with PEG and the interaction between sCT peptide and SF proteins. Compared with traditional needle injection, delivery of sCT using optimized HA-PEG/SF MNs shows better trabecular bone repair for ovariectomized-induced osteoporosis in mice. The proposed MNs system provides a new noninjection strategy for therapy of osteoporosis.


Asunto(s)
Calcitonina , Osteoporosis , Ratones , Animales , Preparaciones de Acción Retardada/farmacología , Administración Cutánea , Calcitonina/farmacología , Calcitonina/química , Osteoporosis/tratamiento farmacológico , Sistemas de Liberación de Medicamentos , Agujas
8.
Lab Chip ; 22(24): 4962-4973, 2022 12 06.
Artículo en Inglés | MEDLINE | ID: mdl-36420612

RESUMEN

Controllable mass production of monodisperse droplets plays a key role in numerous fields ranging from scientific research to industrial application. Microfluidic ladder networks show great potential in mass production of monodisperse droplets, but their design with uniform microflow distribution remains challenging due to the lack of a rational design strategy. Here an effective design strategy based on backstepping microflow analysis (BMA) is proposed for the rational development of microfluidic ladder networks for mass production of controllable monodisperse microdroplets. The performance of our BMA rule for rational microfluidic ladder network design is demonstrated by using an existing analogism-derived rule that is widely used for the design of microfluidic ladder networks as the control group. The microfluidic ladder network designed by the BMA rule shows a more uniform flow distribution in each branch microchannel than that designed by the existing rule, as confirmed by single-phase flow simulation. Meanwhile, the microfluidic ladder network designed by the BMA rule allows mass production of droplets with higher size monodispersity in a wider window of flow rates and mass production of polymeric microspheres from such highly monodisperse droplet templates. The proposed BMA rule provides new insights into the microflow distribution behaviors in microfluidic ladder networks based on backstepping microflow analysis and provides a rational guideline for the efficient development of microfluidic ladder networks with uniform flow distribution for mass production of highly monodisperse droplets. Moreover, the BMA method provides a general analysis strategy for microfluidic networks with parallel multiple microchannels for rational scale-up.


Asunto(s)
Microfluídica
9.
Colloids Surf B Biointerfaces ; 219: 112806, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36088828

RESUMEN

The poor bacteriostasis and osseointegration properties of bioinert polyetheretherketone (PEEK) hinder its clinical application. This work reports a simple and versatile strategy for fabricating dual-functional coating with programmed sequential drug release properties on porous PEEK surfaces. The dual-drug-loaded composite coating composed of drug-loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles and drug-loaded polyvinyl alcohol (PVA) gel can be immobilized on the surface of sulfonated PEEK by a cyclic freeze-thaw method. Based on the swelling of PVA and the slow degradation of PLGA, the composite coating can realize rapid release of antibacterial drugs and sustained release of osteogenic drugs. The in vitro antibacterial evaluations show that the porous PEEK modified with drug-loaded composite gel coating exhibits an early effective fight against Staphylococcus aureus (S.aureus). The results of in vitro cell experiments show that the PEEK materials modified by the composite gel coating can well support the normal growth, adhesion and proliferation of cells. In addition, the PEEK material coated with the drug-loaded composite gel is found to have positive effects on the osteogenic differentiation of cells in detections of alkaline phosphatase (ALP) activity of cells and the amount of calcium deposition on the surface of the material. The results demonstrate that the proposed porous PEEK modified with dual-drug-loaded composite gel coating simultaneously exhibits excellent osseointegration and exerts early effective antibacterial activity. This dual-functional PEEK material has great application potential in clinical bone tissue repair.

10.
Biomater Adv ; 139: 213001, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35882148

RESUMEN

A composite microneedle patch (MN patch) is developed for oral transmucosal administration. To improve the oral transmucosal drug delivery efficiency, the composite MN patch is designed to consist of an array of 100 dissolvable microneedles (MNs) with drug-loaded tips and a backing layer. The MNs are composed of two parts, the hyaluronic acid (HA) tip part and the polyvinylpyrrolidone (PVP) base part. Due to the small size and sufficient mechanical strength, the HA-PVP MNs can painlessly penetrate the oral mucosa barrier and deliver drugs directly to the basal layer or submucosa. Betamethasone sodium phosphate (BSP), as the model drug, is concentrated in the HA tip parts to avoid the drug waste caused by mucosa elasticity. Considering the special moist environment and saliva flow in the mouth, a double-layer backing layer composed of a poly(vinyl alcohol) (PVA) adhesive layer and an ethyl cellulose (EC) waterproof layer is designed and constructed, which could reduce the saliva flow effects. The in vitro and in vivo results demonstrate that the MN patch could achieve rapid and efficient BSP release in oral mucosa due to the rapid dissolution of HA. The proposed MN patch provides a novel strategy for the therapy of oral mucosal diseases.


Asunto(s)
Sistemas de Liberación de Medicamentos , Ácido Hialurónico , Sistemas de Liberación de Medicamentos/métodos , Alcohol Polivinílico
11.
Macromol Rapid Commun ; 43(11): e2200127, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35334130

RESUMEN

Biological polyampholytes are ubiquitous in living organisms with primary functions including serving as transporters for moving chemical molecular species across the cell membranes. Synthetic amphoteric macromolecules that can change their phase states depending on the environment to simulate some properties of natural polyampholytes are of great interest. Here, the implementation of synthetic pseudo polymeric ampholytes is explored with ion-recognition-triggered conformational change. The phase transition behaviors of the ion-recognition-creative polyampholytes that contain deprotonated carboxylic acid groups as negative charges and 18-crown-6 units for forming positively charged host-guest complexes are systematically investigated. The ion-recognition-triggered phase transition behaviors of pseudo polyampholytes significantly depend on cation species and concentrations. Only those specific ions such as K+ , Ba2+ , Sr2+ and Pb2+ ions that can form 1:1 host-guest complexes with 18-crown-6 units in polymers enable control over conformational change like that of traditional pH-dependent polyampholytes. By regulating the content of carboxylic acid groups to match the content of ion-recognized positive charges provided by the host-guest complexes, the pseudo polyampholytes are more sensitive to the recognizable cations. Such ion-recognition-triggered amphoteric characteristics make the pseudo polyampholytes act like biological proteins, nucleic acids, and enzymes as molecular transporters, genetic code storage, and biocatalysts in artificial systems.


Asunto(s)
Ácidos Carboxílicos , Polímeros , Iones/química , Conformación Molecular , Transición de Fase , Polímeros/química
12.
Langmuir ; 38(3): 1277-1286, 2022 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-35015552

RESUMEN

It is well-known that surfactants tend to aggregate into clusters or micelles in aqueous solutions due to their special structures, and it is difficult for the surfactant molecules involved in the aggregation to move spontaneously to the oil-water interface. In this article, we developed a new grand-canonical molecular dynamics (GCMD) model to predict the saturated adsorption amount of surfactant with constant concentration of surfactant molecules in the bulk phase, which can prevent surfactants aggregating in the bulk phase and get the atomic details of the interfacial structural change with increase of the adsorption amount through a single GCMD run. The adsorption of anionic surfactant sodium dodecyl sulfate (SDS) at the heptane-water interface was studied to validate the model. The saturated adsorption amount obtained from the GCMD simulation is consistent with the experimental results. The adsorption kinetics of SDS molecules during the simulation can be divided into three stages: linear adsorption stage, transition adsorption stage, and dynamic equilibrium stage. We also carried out equilibrium molecular dynamics (EMD) simulations to compare with GCMD simulation. This GCMD model can effectively reduce the simulation time with correct prediction of the interfacial saturation adsorption. We believe the GCMD method could be especially helpful for the computational study of surfactant adsorption under complex environments or emulsion systems with the adsorption of multiple types of surfactants.

13.
J Hazard Mater ; 421: 126801, 2022 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-34388916

RESUMEN

A novel chemosensor is developed for the sensitive and facile detection of trace strontium ions (Sr2+) based on the ion-imprinted hydrogels. With Sr2+ as the templates, the ion-imprinted hydrogels are synthesized by copolymerizing the ion-responsive units 5'-O-acryloyl-2',3'-O-isopropylidene guanosine (APG) and the thermo-responsive units N-isopropylacrylamide (NIPAM). In the presence of Sr2+, APG units can self-assemble to form planar G-quartets via the complexation with Sr2+, which are introduced into the gel network during polymerization. Then Sr2+ templates can be removed by multiple repeated washing. When re-exposed to Sr2+, the relaxed G-quartets can recognize Sr2+, leading to the weakening of electrostatic repulsion between the four oxygen atoms in the G-quartets and inducing the shrinkage of the hydrogels. In this work, the Sr2+-imprinted chemosensors are designed as the grating systems for detecting trace Sr2+. Based on the array of hydrogel strings synthesized on a nano-scale, the smart grating systems thus constructed can convert and amplify the Sr2+ concentration signals to the easily-measurable optical signals. With the Sr2+-imprinted hydrogel gratings, trace Sr2+ (10-11 M) in an aqueous solution can be detected sensitively. Moreover, the proposed Sr2+-imprinted chemosensors can be integrated with other smart systems for developing various detectors with high performance.


Asunto(s)
Hidrogeles , Estroncio , Guanosina , Iones , Polimerizacion
14.
Adv Mater ; 34(46): e2107877, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34897843

RESUMEN

Smart polymeric materials with dynamically tunable physico-chemical characteristics in response to changes of environmental stimuli, have received considerable attention in myriad fields. The diverse combination of their micro-/nano-structural and molecular designs creates promising and exciting opportunities for exploiting advanced smart polymeric materials. Engineering micro-/nano-structures into smart polymeric materials with elaborate molecular design enables intricate coordination between their structures and molecular-level response to cooperatively realize smart functions for practical applications. In this review, recent progresses of smart polymeric materials that combine micro-/nano-structures and molecular design to achieve designed advanced functions are highlighted. Smart hydrogels, gating membranes, gratings, milli-particles, micro-particles and microvalves are employed as typical examples to introduce their design and fabrication strategies. Meanwhile, the key roles of interplay between their micro-/nano-structures and responsive properties to realize the desired functions for their applications are emphasized. Finally, perspectives on the current challenges and opportunities of micro-/nano-structured smart polymeric materials for their future development are presented.

15.
ACS Appl Mater Interfaces ; 13(24): 28802-28817, 2021 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-34109788

RESUMEN

In this study, a novel class of multifunctional responsive nanoparticles is designed and fabricated as drug nanocarriers for synergetic chemo-photothermal therapy of tumors. The proposed nanoparticles are composed of a thermo-/pH-responsive poly(N-isopropylacrylamide-co-acrylic acid) (PNA) nanogel core, a polydopamine (PDA) layer for photothermal conversion, and an outer folic acid (FA) layer as a targeting agent for the folate receptors on tumor cells. The fabricated nanoparticles show good biocompatibility and outstanding photothermal conversion efficiency. The proposed nanoparticles loaded with doxorubicin (DOX) drug molecules are stable under physiological conditions with low leakage of drugs, while rapidly release drugs in environments with low pH conditions and at high temperature. The experimental results show that the drug release process is mainly governed by Fickian diffusion. In vitro cell experimental results demonstrate that the PNA-DOX@PDA-FA nanoparticles can be phagocytized by 4T1 tumor cells and release drugs in tumor cell acidic environments, and confirm that the combined chemo and photothermal therapeutic efficacy of PNA-DOX@PDA-FA nanoparticles is higher than the photothermal therapeutic efficacy or the chemotherapeutic efficacy alone. The proposed multifunctional responsive nanoparticles in this study provide a novel class of drug nanocarriers as a promising tool for synergetic chemo-photothermal therapy of tumors.


Asunto(s)
Antineoplásicos/farmacología , Doxorrubicina/farmacología , Portadores de Fármacos/química , Nanopartículas Multifuncionales/química , Acrilamidas/química , Acrilamidas/metabolismo , Animales , Antineoplásicos/química , Línea Celular Tumoral , Doxorrubicina/química , Portadores de Fármacos/metabolismo , Portadores de Fármacos/efectos de la radiación , Liberación de Fármacos , Endocitosis/fisiología , Ácido Fólico/análogos & derivados , Ácido Fólico/metabolismo , Humanos , Concentración de Iones de Hidrógeno , Indoles/química , Indoles/metabolismo , Indoles/efectos de la radiación , Rayos Infrarrojos , Ratones , Nanopartículas Multifuncionales/metabolismo , Terapia Fototérmica , Polímeros/química , Polímeros/metabolismo , Polímeros/efectos de la radiación , Temperatura
16.
Macromol Rapid Commun ; 42(15): e2100200, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-34028919

RESUMEN

Thermochromic poly(N-isopropyl acrylamide) (PNIPAM) photonic crystal gels based on 1D magnetically assembling colloidal nanocrystal clusters have attracted much attention due to its convenient preparation process, striking color response, and good mechanical strength. However, there remain challenges to broaden the thermochromic range and improve the sensitivity for their iridescent color display. Here, a PNIPAM photonic gel with wide thermochromic range and high sensitivity is prepared by using four-arm star poly(ethylene glycol) acrylamide (PEGAAm) as cross-linker at appropriately reduced magnetic field strength as well as cross-linker content. PEGAAm improves the homogeneity of the microstructure in PNIPAM photonic gel and thus maintains the structure colors at a wide temperature range from room temperature to 44 °C. The reduced magnetic field strength of 70 Gs and low cross-linker content (the molar ratio of monomer to cross-linker of 300:1) lead to a large initial lattice spacing of the photonic gel and thus wide diffraction wavelength migration of 194 nm. This optimized PNIPAM gel exhibits vivid iridescent colors from orange-red to indigo blue as temperature increases from 20 to 44 °C with satisfactory repeatability. Therefore, it may be an ideal candidate for temperature sensors and displays with utility and accuracy such as low-temperature burns.


Asunto(s)
Nanopartículas , Óptica y Fotónica , Geles , Fotones , Temperatura
17.
J Hazard Mater ; 404(Pt A): 124157, 2021 02 15.
Artículo en Inglés | MEDLINE | ID: mdl-33039826

RESUMEN

A simple and portable thermometer-type device based on forward osmosis-driven liquid column rising is developed for visual detection of trace Pb2+. The device consists of a top indicator tube, a chamber loaded with Pb2+-responsive poly(N-isopropylacrylamide-co-benzo-18-crown-6-acrylamide) (PNB) smart nanogels and a bottom semipermeable membrane. Upon the recognition of Pb2+, PNB smart nanogels undergo a Pb2+-induced hydrophobic to hydrophilic transition, which simultaneously causes the increase of osmotic pressure inside the device. Driven by this osmotic pressure difference, more Pb2+ solution flows into the device, causing the rise of the liquid column in the indicator tube, which can be directly observed by naked eyes. The relationship between the change of liquid column height and the Pb2+ concentration is investigated for the quantitative detection of Pb2+. With the proposed forward osmosis-driven device, trace Pb2+ as low as 10-10 M in aqueous solutions can be detected. This method provides a novel and simple strategy for the visual detection of trace Pb2+.

18.
ACS Appl Mater Interfaces ; 12(51): 57514-57525, 2020 Dec 23.
Artículo en Inglés | MEDLINE | ID: mdl-33301686

RESUMEN

In this work, a simple and flexible method for the fabrication of chitosan microcapsules with controllable structures and functions via the interfacial cross-linking reaction of the water-in-oil (W/O) emulsion templates is developed. The interfacial cross-linking reactions of chitosan and terephthalaldehyde (TPA) in W/O emulsion templates are comprehensively studied. The interfacial cross-linking reactions of the droplet templates in both batchwise and continuous conditions are studied. A poly(dimethylsiloxane) (PDMS) droplet-capture microfluidic chip is fabricated to investigate the interfacial reaction in continuous conditions online. In this study, the size and shell thickness of the microcapsules are affected by the preparation condition, such as the template size, emulsifier concentration, TPA concentration, and cross-linking time. Moreover, the size and shell thickness changes of chitosan microcapsules prepared in continuous conditions are much faster than those prepared in batchwise conditions. By regulating the preparation parameters, the microcapsules with controllable structures are fabricated in both batchwise and continuous conditions. The drug release behaviors of the microcapsules with controllable structures are studied. Furthermore, by adding magnetic nanoparticles to the aqueous solution, magnetic-responsive microcapsules are fabricated easily. This work provides valuable guidance for the controllable fabrication of chitosan microcapsules with designed structures and functions via single emulsion templates.


Asunto(s)
Benzaldehídos/química , Cápsulas/química , Quitosano/química , Reactivos de Enlaces Cruzados/química , Dextranos/química , Portadores de Fármacos/química , Liberación de Fármacos , Emulsiones/química , Fluoresceína-5-Isotiocianato/análogos & derivados , Fluoresceína-5-Isotiocianato/química , Colorantes Fluorescentes/química , Fenómenos Magnéticos , Nanopartículas de Magnetita/química , Microfluídica/métodos , Aceite de Soja/química , Agua/química
19.
ACS Appl Mater Interfaces ; 12(50): 56269-56280, 2020 Dec 16.
Artículo en Inglés | MEDLINE | ID: mdl-33264002

RESUMEN

Graphene oxide (GO) membranes have shown enormous promise in desalination and molecular/ionic sieving. However, the instability of GO membranes in aqueous solutions seriously hinders their practical applications. Herein, we report a novel and simple strategy to fabricate stable GO membranes in water-based environments through the insertion of various metal cations from metal foils (e.g., copper (Cu), iron (Fe), nickel (Ni), and zinc (Zn) foils) and natural deposition. Based on the cation-π, coordination, and electrostatic interaction between metal cations and GO nanosheets, the aqueous stability and mechanical strength of the membranes are significantly improved. The permeation rates for acetone, toluene, and p-xylene molecules across the GO membrane cross-linked by copper ions with a deposition time of 24 h are 0.966, 0.074, and 0.100 mol m-2 h-1, respectively. Moreover, this membrane displays excellent separation performance, and the separation factor of K+/Mg2+ is up to 68.8 in mono-/multivalent metal cation sieving, which indicate the effective molecular/ionic sieving performance. Meanwhile, the ionic sieving of the GO membrane cross-linked by copper ions has excellent repeatability and long-term stability. The versatility of this natural deposition strategy to fabricate GO membranes cross-linked by metal cations is investigated by using Fe foil, Zn foil, and Ni foil as well as other porous substrates such as polyvinylidene fluoride (PVDF), polyethersulfone (PES), and nylon membranes and filter paper. This fabrication strategy also enables low-cost preparation of large-area GO membranes. Therefore, GO membranes cross-linked by metal cations and prepared by this simple metal cation incorporation strategy have large potential application for molecular/ionic sieving in various solution systems.

20.
Biomicrofluidics ; 14(6): 061501, 2020 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-33193936

RESUMEN

Microstructured functional materials such as microfibers and microparticles are widely used for a myriad of applications. Precise manipulation of the functional components and structure is important for the microstructured functional materials to achieve desired functions for advanced application. This review highlights the recent progress on the controllable microfluidic fabrication of microstructured functional materials from liquid templates. First, microfluidic strategies for controllable generation of liquid templates including laminar jets and emulsion droplets are introduced. Then, strategies for fabricating microfibers and microparticles with diverse structures and advanced functions from the liquid templates are highlighted. These strategies mainly focus on precisely engineering the functional components and microstructures of the microfibers and microparticles by tailoring those of their liquid templates to achieve desired advanced functions. Finally, future development of microfluidic techniques for industrial-scale production of the microstructured functional materials is discussed.

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