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1.
J Colloid Interface Sci ; 581(Pt A): 31-43, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-32768733

RESUMO

The use of nanoscale metal-organic frameworks (MOFs) as drug delivery vehicles has attracted considerable attention in tumor therapy. In this study, novel biocompatible MOF-based nanocarriers were used as part of a facile and reproducible strategy for precision cancer theranostics. Both diagnostic (Mn2+) and therapeutic compounds (doxorubicin, DOX) were incorporated into the multifunctional MOF-based nanocarriers, which exhibited high colloidal stability and promoted T1-weighted proton relaxivity and low-pH-activated drug release. The obtained MOF-based nanocarriers exhibited significantly high cellular uptake and efficient intracellular drug delivery into cancer cells, which resulted in high apoptosis and cytotoxicity, in addition to effectively inhibiting the migration of 4T1 breast cancer cells. Moreover, the MOF-based nanocarriers could intensively deliver diagnostic and therapeutic agents to tumors to enable precise visualization of the nanocarrier accumulation and accurate tumor positioning, diagnosis, and imaging-guided therapy using magnetic resonance imaging (MRI). In addition, the functional MOF-based nanocarriers exhibited effective ablation of the primary breast cancer, as well as significant inhibition of lung metastasis with a high survival rate. Therefore, the developed nanocarriers represent a viable platform for cancer theranostics.

2.
ACS Appl Mater Interfaces ; 11(38): 35496-35500, 2019 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-31469536

RESUMO

We developed a robust, crack-free ultrathin zeolite- imidazole framework (ZIF-8) membrane in-built with a sulfonate-ion-containing polymer (ZIFHep) via a vapor-assisted in situ conversion process. The sulfonated sub-nanochannels of the ZIFHep membrane afforded a rapid and selective transport of Li+ over counteranions and other alkali ions due to electrostatic repulsion and optimal transport kinetics of cation-sulfonate ion pairs. A salinity gradient power generator (SGPG) was built by using the ZIFHep membrane as a cell separator coupled with a pair of Ag/AgCl porous membrane electrodes. At a salinity gradient of 105, such a power generator presented a significantly decreased internal resistance (25.6 Ω), three-order of magnitude lower than that reported previously, and an output power as high as 9.03 µW.

3.
Nat Nanotechnol ; 14(5): 407, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30886377
4.
J Am Chem Soc ; 141(1): 53-57, 2019 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-30580521

RESUMO

A layered metal-organic framework (MOF) with a porous kagomé lattice, kgmSMe, was synthesized by complexation of 5-methylthioisophthalate (SMe-ip) with Cu2+ in MeOH. As observed by powder XRD, kgmSMe (state I), when immersed in aprotic polar solvents such as THF, underwent stepwise interlayer expansion into a monolayer-expanded state (state III) through a bilayer-expanded state (state II). We successfully obtained the single-crystal structures of states I-III. Of interest, when further immersed in appropriate solvents, state II and III crystals preferentially exfoliated into bilayer and monolayer MOF nanosheets, respectively. The stepwise expansion followed by exfoliation, thus developed, may enable a nonstochastic approach to the selective synthesis of ultrathin porous nanosheets from layered MOF crystals.

5.
J Am Chem Soc ; 139(26): 8784-8787, 2017 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-28635263

RESUMO

An azobenzene-containing, zirconium-based metal-organic framework (AzoMOF), upon irradiation with ultraviolet (UV) light at 365 ± 10 nm, underwent trans-to-cis isomerization of its azobenzene pendants to furnish the cis-isomer content of 21% (AzoMOF21%) in 30 min at the photostationary state and underwent backward isomerization into AzoMOF1% upon either irradiation with visible light (420-480 nm) or heating. When the cis-isomer content increased, the diffusion rate and amount of CO2 adsorbed into the nanochannels of AzoMOF decreased considerably. When erythrosine B, a polarity-probing guest, was used, it showed a red shift upon exposure of AzoMOF20%⊃EB to visible light, indicating that the interior environment of AzoMOF turns less polar as the trans-isomer content becomes higher. In sharp contrast, the adsorption profiles of AzoMOF15% and AzoMOF1% for Ar having an analogous kinetic diameter to CO2 but no quadrupole moment and a smaller polarizability were virtually identical to one another. Therefore, it is likely that CO2 experiences a dominant effect of a polar effect rather than a steric effect in the crystalline nanochannels.


Assuntos
Compostos Azo/química , Nanotecnologia , Adsorção , Dióxido de Carbono/química , Cristalização , Difusão , Estruturas Metalorgânicas/química , Modelos Moleculares , Zircônio/química
6.
ACS Nano ; 8(6): 6304-11, 2014 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-24853383

RESUMO

Two-dimensional layered materials have joined in the family of size-selective separation membranes recently. Here, chemically exfoliated tungsten disulfide (WS2) nanosheets are assembled into lamellar thin films and explored as an ultrafast separation membrane for small molecules with size of about 3 nm. Layered WS2 membranes exhibit 5- and 2-fold enhancement in water permeance of graphene oxide membranes and MoS2 laminar membranes with similar rejection, respectively. To further increase the water permeance, ultrathin nanostrands are used as templates to generate more fluidic channel networks in the WS2 membrane. The water permeation behavior and separation performance in the pressure loading-unloading process reveal that the channels created by the ultrathin nanostrands are cracked under high pressure and result in a further 2-fold increase of the flux without significantly degrading the rejection for 3 nm molecules. This is supported by finite-element-based mechanical simulation. These layered WS2 membranes demonstrate up to 2 orders of magnitude higher separation performance than that of commercial membranes with similar rejections and hold the promising potential for water purification.

7.
Chem Commun (Camb) ; 50(34): 4485-8, 2014 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-24664225

RESUMO

Hybrid lamellar porous electrodes with excellent electrochemical performance were successfully fabricated by homogeneously intercalating single-walled carbon nanotubes into the lamellar assembled WS2 nanosheets through vacuum filtration.

8.
Nat Commun ; 4: 2979, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24352165

RESUMO

Pressure-driven ultrafiltration membranes are important in separation applications. Advanced filtration membranes with high permeance and enhanced rejection must be developed to meet rising worldwide demand. Here we report nanostrand-channelled graphene oxide ultrafiltration membranes with a network of nanochannels with a narrow size distribution (3-5 nm) and superior separation performance. This permeance offers a 10-fold enhancement without sacrificing the rejection rate compared with that of graphene oxide membranes, and is more than 100 times higher than that of commercial ultrafiltration membranes with similar rejection. The flow enhancement is attributed to the porous structure and significantly reduced channel length. An abnormal pressure-dependent separation behaviour is also reported, where the elastic deformation of nanochannels offers tunable permeation and rejection. The water flow through these hydrophilic graphene oxide nanochannels is identified as viscous. This nanostrand-channelling approach is also extendable to other laminate membranes, providing potential for accelerating separation and water-purification processes.

9.
Chem Commun (Camb) ; 49(91): 10718-20, 2013 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-24100417

RESUMO

For the first time, a laminar separation membrane was assembled from atom-thick MoS2 sheets and exhibited a water permeance of 245 L h(-1) m(-2) bar(-1), which was 3-5 times higher than that of graphene oxide membranes without degradation of the rejection ratio (89%) for Evans blue molecules.

10.
Dalton Trans ; 42(36): 13265-72, 2013 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-23887280

RESUMO

[Fe(CN)6](4-) decorated mesoporous gelatin films, acting as colorimetric sensors and sorbents for heavy metal ions, were prepared by incorporating [Fe(CN)6](4-) ions into the mesoporous gelatin films through electrostatic interaction. Gelatin-Prussian blue (PB) and gelatin-PB analogue composite films were successfully synthesized by immersing the [Fe(CN)6](4-) decorated gelatin films into aqueous solutions of metal ions, such as Fe(3+), Cu(2+), Co(2+), Pb(2+) and Cd(2+) (all as nitrates). The in situ formation process of PB or its analogues in the films was investigated using quartz crystal microbalance (QCM) measurements. According to the different colors of the PB nanoparticles and its analogues, the [Fe(CN)6](4-) decorated mesoporous gelatin films demonstrated colorimetric sensor abilities for detecting the corresponding metal ions by the naked eye with sufficient sensitivity at 1 ppm level and a quite short response time of 5 minutes. Moreover, due to the [Fe(CN)6](4-) functionality and other functional groups of gelatin itself, this [Fe(CN)6](4-) decorated mesoporous gelatin film shows a tens times higher adsorption ability for heavy metal ions in water than that of activated carbon. Due to both the efficient detection and high adsorption ability for heavy metal ions, this film has wide potential applications for the detection and purification of heavy metal ions from polluted water.

11.
Chem Commun (Camb) ; 49(50): 5666-8, 2013 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-23682358

RESUMO

Large scale, robust, well intergrown free-standing HKUST-1 membranes were converted from copper hydroxide nanostrand free-standing films in 1,3,5-benzenetricarboxylic acid water-ethanol solution at room temperature, and explored for gas separation. The truncated crystals are controllable and favorable for the dense intergrowth.

12.
Chem Commun (Camb) ; 49(53): 5963-5, 2013 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-23715402

RESUMO

For the first time, pressure, salt concentration and pH demonstrated advantages for tuning the nanochannels within lamellar graphene oxide (LGO) membranes to control the separation of small molecules. This provides a new avenue for designing and engineering efficient LGO membranes for molecular separation.

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