scholarly journals Cooperative Binding and Stepwise Encapsulation of Drug Molecules by Sulfonylcalixarene-Based Metal-Organic Supercontainers

Molecules ◽  
2020 ◽  
Vol 25 (11) ◽  
pp. 2656
Author(s):  
Tian-Pu Sheng ◽  
Xin-Xia Fan ◽  
Guo-Zong Zheng ◽  
Feng-Rong Dai ◽  
Zhong-Ning Chen
Keyword(s):  
Chloroform Solution ◽  
Hill Equation ◽  
Cooperative Binding ◽  
Synthetic Receptors ◽  
Guest Molecules ◽  
Binding Behavior ◽  
Drug Molecules ◽  
Titration Curves ◽  
Metal Organic ◽  
Titration Technique

The cooperative binding behavior of a face-directed octahedral metal-organic supercontainer featuring one endo cavity and six exo cavities was thoroughly examined in chloroform solution through ultraviolet-visible (UV-Vis) titration technique using two representative drug molecules as the guests. The titration curves and their nonlinear fit to Hill equation strongly suggest the efficient encapsulation of the guest molecules by the synthetic host, which exhibit interesting cooperative and stepwise binding behavior. Based on the control experiments using tetranuclear complex as a reference, it is clear that two equivalents of the guest molecules are initially encapsulated inside the endo cavity, followed by the trapping of six additional equivalents of the drug molecules through six exo cavities (1 eq. per exo cavity), and the remaining guests are entrapped by the external pockets. The results provide an in-depth understanding of the cooperative binding behavior of metal-organic supercontainers, which opens up new opportunities for designing synthetic receptors for truly biomimetic functional applications.

Synthesis and Structure of a Clathrated Two-Dimensional Metal-Organic Framework: [Cd(4,4'-bpy)2(H2O)2](ClO4)2·(L)2·H2O (L = Bis(1-pyrazinylethylidene)hydrazine)

2008 ◽  
Vol 73 (1) ◽  
pp. 24-31
Author(s):  
Dayu Wu ◽  
Genhua Wu ◽  
Wei Huang ◽  
Zhuqing Wang
Keyword(s):  
Metal Organic Framework ◽  
Channel Structure ◽  
Two Dimensional ◽  
X Ray Diffraction ◽  
Guest Molecules ◽  
X Ray ◽  
Square Planar ◽  
Metal Organic ◽  
Aqueous Meoh ◽  
Organic Framework

The compound [Cd(4,4'-bpy)2(H2O)2](ClO4)2·(L)2 was obtained by the reaction of Cd(ClO4)2, bis(1-pyrazinylethylidene)hydrazine (L) and 4,4'-bipyridine in aqueous MeOH. Single-crystal X-ray diffraction has revealed its two-dimensional metal-organic framework. The 2-D layers superpose on each other, giving a channel structure. The square planar grids consist of two pairs of shared edges with Cd(II) ion and a 4,4'-bipyridine molecule each vertex and side, respectively. The square cavity has a dimension of 11.817 × 11.781 Å. Two guest molecules of bis(1-pyrazinylethylidene)hydrazine are clathrated in every hydrophobic host cavity, being further stabilized by π-π stacking and hydrogen bonding. The results suggest that the hydrazine molecules present in the network serve as structure-directing templates in the formation of crystal structures.

scholarly journals Metal-Organic Framework-Based Stimuli-Responsive Polymers

2021 ◽  
Vol 5 (4) ◽  
pp. 101
Author(s):  
Menglian Wei ◽  
Yu Wan ◽  
Xueji Zhang
Keyword(s):  
Metal Organic Framework ◽  
Chemical Properties ◽  
Stimuli Responsive ◽  
Guest Molecules ◽  
Stimuli Responsive Polymers ◽  
Responsive Polymers ◽  
Reversible Phase Transition ◽  
Metal Organic ◽  
External Stimuli ◽  
Organic Framework

Metal-organic framework (MOF) based stimuli-responsive polymers (coordination polymers) exhibit reversible phase-transition behavior and demonstrate attractive properties that are capable of altering physical and/or chemical properties upon exposure to external stimuli, including pH, temperature, ions, etc., in a dynamic fashion. Thus, their conformational change can be imitated by the adsorption/desorption of target analytes (guest molecules), temperature or pressure changes, and electromagnetic field manipulation. MOF-based stimuli responsive polymers have received great attention due to their advanced optical properties and variety of applications. Herein, we summarized some recent progress on MOF-based stimuli-responsive polymers (SRPs) classified by physical and chemical responsiveness, including temperature, pressure, electricity, pH, metal ions, gases, alcohol and multi-targets.

Engineering an iridium-containing metal–organic molecular capsule for induced-fit geometrical conversion and dual catalysis

2016 ◽  
Vol 52 (62) ◽  
pp. 9628-9631 ◽  
Author(s):  
Xuezhao Li ◽  
Jinguo Wu ◽  
Liyong Chen ◽  
Xiaoming Zhong ◽  
Cheng He ◽  
...  
Keyword(s):  
Cooperative Binding ◽  
Induced Fit ◽  
Molecular Capsule ◽  
Metal Organic ◽  
Dual Catalysis ◽  
Carbonate Anion

Quantitative dynamic capsule–capsule conversion by cooperative binding one carbonate anion and switchable dual catalysis was achieved within an Ir2Co3-type capsule.

Azobenzene-Functionalized Metal-Organic Polyhedra for the Optically Responsive Capture and Release of Guest Molecules

2014 ◽  
Vol 53 (23) ◽  
pp. 5842-5846 ◽  
Author(s):  
Jinhee Park ◽  
Lin-Bing Sun ◽  
Ying-Pin Chen ◽  
Zachary Perry ◽  
Hong-Cai Zhou
Keyword(s):  
Guest Molecules ◽  
Metal Organic ◽  
Capture And Release

scholarly journals Synthesis and Guest-Binding Properties of pH/Reduction Dual-Responsive Cyclophane Dimer

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3097
Author(s):  
Osamu Hayashida ◽  
Yudai Tanaka ◽  
Takaaki Miyazaki
Keyword(s):  
Electrostatic Interaction ◽  
Disulfide Bonds ◽  
Water Soluble ◽  
Guest Molecules ◽  
Binding Behavior ◽  
Dual Responsive ◽  
Guest Binding ◽  
Basic Solutions ◽  
Ph Conditions ◽  
Almost All

A water-soluble cyclophane dimer having two disulfide groups as a reduction-responsive cleavable bond as well as several acidic and basic functional groups as a pH-responsive ionizable group 1 was successfully synthesized. It was found that 1 showed pH-dependent guest-binding behavior. That is, 1 strongly bound an anionic guest, 6-p-toluidinonaphthalene-2-sulfonate (TNS) with binding constant (K/M−1) for 1:1 host-guest complexes of 9.6 × 104 M−1 at pH 3.8, which was larger than those at pH 7.4 and 10.7 (6.0 × 104 and 2.4 × 104 M−1, respectively), indicating a favorable electrostatic interaction between anionic guest and net cationic 1. What is more, release of the entrapped guest molecules by 1 was easily controlled by pH stimulus. Large favorable enthalpies (ΔH) for formation of host-guest complexes were obtained under the pH conditions employed, suggesting that electrostatic interaction between anionic TNS and 1 was the most important driving force for host-guest complexation. Such contributions of ΔH for formation of host-guest complexes decreased along with increased pH values from acidic to basic solutions. Upon addition of dithiothreitol (DTT) as a reducing reagent to an aqueous PBS buffer (pH 7.4) containing 1 and TNS, the fluorescence intensity originating from the bound guest molecules decreased gradually. A treatment of 1 with DTT gave 2, having less guest-binding affinity by the cleavage of disulfide bonds of 1. Consequently, almost all entrapped guest molecules by 1 were released from the host. Moreover, such reduction-responsive cleavage of 1 and release of bound guest molecules was performed more rapidly in aqueous buffer at pH 10.7.

scholarly journals Elucidating the Drug Release from Metal-Organic Framework Nanocomposites via in Situ Synchrotron Microspectroscopy and Theoretical Modelling

2019 ◽  
Author(s):  
Barbara Souza ◽  
Lorenzo Dona ◽  
Kirill Titov ◽  
Paolo Bruzzese ◽  
Zhixin Zeng ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Density Functional ◽  
Metal Organic Framework ◽  
Density Functional Theory Calculations ◽  
Theoretical Modelling ◽  
Time Resolved ◽  
Drug Molecules ◽  
Metal Organic

Nanocomposites comprising metal-organic frameworks (MOFs) embedded in a polymeric matrix are promising carriers for drug delivery applications. While understanding the chemical and physical transformations of MOFs during the release of confined drug molecules is challenging, this is central to devising better ways for controlled release of therapeutic agents. Herein we demonstrate the efficacy of synchrotron microspectroscopy to track the in situ release of 5-fluorouracil (5-FU) anticancer drug molecules from a drug@MOF/polymer composite (5-FU@HKUST-1/polyurethane). Using experimental time-resolved infrared spectra jointly with newly developed density functional theory calculations, we reveal the detailed dynamics of vibrational motions underpinning the dissociation of 5-FU bound to the framework of HKUST-1 upon water exposure. We discover that HKUST-1 creates hydrophilic channels within the hydrophobic polyurethane matrix hence helping to tune drug release rate. The synergy between a hydrophilic MOF with a hydrophobic polymer can be harnessed to engineer a tunable nanocomposite that alleviates the unwanted burst effect commonly encountered in drug delivery.<br>

scholarly journals Gas Adsorption Selectivity in Topologically Disordered Metal–Organic Frameworks

2021 ◽  
Author(s):  
Adam Sapnik ◽  
Christopher W. Ashling ◽  
Lauren K. Macreadie ◽  
Seok J. Lee ◽  
Tim Johnson ◽  
...  
Keyword(s):  
Gas Adsorption ◽  
Metal Organic Frameworks ◽  
Interaction Strength ◽  
Functional Materials ◽  
Adsorption Selectivity ◽  
Guest Molecules ◽  
Sorption Behaviour ◽  
Ideal Adsorbed Solution Theory ◽  
Industrial Gases ◽  
Metal Organic

<div><p>Disordered metal–organic frameworks are emerging as an attractive class of functional materials, however their applications in gas storage and separation have yet to be fully explored. Here, we investigate gas adsorption in the topologically disordered Fe-BTC framework and its crystalline counterpart, MIL‑100. Despite their similar chemistry and local structure, they exhibit very different sorption behaviour towards a range of industrial gases, noble gases and hydrocarbons. Virial analysis reveals that Fe-BTC has enhanced interaction strength with guest molecules compared to MIL‑100. Most notably, we observe striking discrimination between the adsorption of C<sub>3</sub>H<sub>6</sub> and C<sub>3</sub>H<sub>8</sub> in Fe‑BTC, with over a twofold increase in the amount of C<sub>3</sub>H<sub>6</sub> being adsorbed than C<sub>3</sub>H<sub>8</sub>. Thermodynamic selectivity towards a range of industrially relevant binary mixtures is probed using ideal adsorbed solution theory (IAST). Together, this suggests the disordered material may possess powerful separation capabilities that are rare even amongst crystalline frameworks.</p></div>

scholarly journals Elucidating the Drug Release from Metal-Organic Framework Nanocomposites via in Situ Synchrotron Microspectroscopy and Theoretical Modelling

2019 ◽  
Author(s):  
Barbara Souza ◽  
Lorenzo Dona ◽  
Kirill Titov ◽  
Paolo Bruzzese ◽  
Zhixin Zeng ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Drug Release ◽  
Density Functional ◽  
Metal Organic Framework ◽  
Density Functional Theory Calculations ◽  
Theoretical Modelling ◽  
Time Resolved ◽  
Drug Molecules ◽  
Metal Organic

Nanocomposites comprising metal-organic frameworks (MOFs) embedded in a polymeric matrix are promising carriers for drug delivery applications. While understanding the chemical and physical transformations of MOFs during the release of confined drug molecules is challenging, this is central to devising better ways for controlled release of therapeutic agents. Herein we demonstrate the efficacy of synchrotron microspectroscopy to track the in situ release of 5-fluorouracil (5-FU) anticancer drug molecules from a drug@MOF/polymer composite (5-FU@HKUST-1/polyurethane). Using experimental time-resolved infrared spectra jointly with newly developed density functional theory calculations, we reveal the detailed dynamics of vibrational motions underpinning the dissociation of 5-FU bound to the framework of HKUST-1 upon water exposure. We discover that HKUST-1 creates hydrophilic channels within the hydrophobic polyurethane matrix hence helping to tune drug release rate. The synergy between a hydrophilic MOF with a hydrophobic polymer can be harnessed to engineer a tunable nanocomposite that alleviates the unwanted burst effect commonly encountered in drug delivery.<br>

scholarly journals Non-Lamellar Liquid Crystalline Nanocarriers for Thymoquinone Encapsulation

Molecules ◽  
2019 ◽  
Vol 25 (1) ◽  
pp. 16 ◽  
Author(s):  
Anan Yaghmur ◽  
Boi Vi Tran ◽  
Seyed Moein Moghimi
Keyword(s):  
Liquid Crystalline ◽  
Drug Carriers ◽  
Structural Features ◽  
Drug Induced ◽  
Guest Molecules ◽  
Drug Molecules ◽  
Liquid Crystalline Nanoparticles ◽  
The Mean ◽  
Biological Performance ◽  
Glycerol Monooleate

Owing to their unique structural features, non-lamellar liquid crystalline nanoparticles comprising cubosomes and hexosomes are attracting increasing attention as versatile investigative drug carriers. Background: Depending on their physiochemical characteristics, drug molecules on entrapment can modulate and reorganize structural features of cubosomes and hexosomes. Therefore, it is important to assess the effect of guest molecules on broader biophysical characteristics of non-lamellar liquid crystalline nanoparticles, since drug-induced architectural, morphological, and size modifications can affect the biological performance of cubosomes and hexosomes. Methods: We report on alterations in morphological, structural, and size characteristics of nanodispersions composed from binary mixtures of glycerol monooleate and vitamin E on thymoquinone (a molecule with wide therapeutic potentials) loading. Results: Thymoquinone loading was associated with a slight increase in the mean hydrodynamic nanoparticle size and led to structural transitions from an internal biphasic feature of coexisting inverse cubic Fd3m and hexagonal (H2) phases to an internal inverse cubic Fd3m phase (micellar cubosomes) or an internal inverse micellar (L2) phase (emulsified microemulsions, EMEs). We further report on the presence of “flower-like” vesicular populations in both native and drug-loaded nanodispersions. Conclusions: These nanodispersions have the potential to accommodate thymoquinone and may be considered as promising platforms for the development of thymoquinone nanomedicines.

scholarly journals Power of Infrared and Raman Spectroscopies to Characterize Metal-Organic Frameworks and Investigate Their Interaction with Guest Molecules

2020 ◽  
Author(s):  
Konstantin I. Hadjiivanov ◽  
Dimitar A. Panayotov ◽  
Mihail Y. Mihaylov ◽  
Elena Z. Ivanova ◽  
Kristina K. Chakarova ◽  
...  
Keyword(s):  
Metal Organic Frameworks ◽  
Guest Molecules ◽  
Metal Organic
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