scholarly journals Differential Interactions of Chiral Nanocapsules with DNA

2021 ◽  
Vol 22 (2) ◽  
pp. 584
Author(s):  
Amani Zoabi ◽  
Katherine Margulis
Keyword(s):  
Electrostatic Interactions ◽  
Volatile Oil ◽  
Supramolecular Interactions ◽  
The Novel ◽  
Fourfold Increase ◽  
Dna Oligonucleotides ◽  
Oil In Water ◽  
Preferential Binding ◽  
Capsule Size ◽  
Modification Of The Surface

(1) Background: Chiral nanoparticular systems have recently emerged as a compelling platform for investigating stereospecific behavior at the nanoscopic level. We describe chiroselective supramolecular interactions that occur between DNA oligonucleotides and chiral polyurea nanocapsules. (2) Methods: We employ interfacial polyaddition reactions between toluene 2,4-diisocyanate and lysine enantiomers that occur in volatile oil-in-water nanoemulsions to synthesize hollow, solvent-free capsules with average sizes of approximately 300 nm and neutral surface potential. (3) Results: The resultant nanocapsules exhibit chiroptical activity and interact differentially with single stranded DNA oligonucleotides despite the lack of surface charge and, thus, the absence of significant electrostatic interactions. Preferential binding of DNA on d-polyurea nanocapsules compared to their l-counterparts is demonstrated by a fourfold increase in capsule size, a 50% higher rise in the absolute value of negative zeta potential (ζ-potential), and a three times lower free DNA concentration after equilibration with the excess of DNA. (4) Conclusions: We infer that the chirality of the novel polymeric nanocapsules affects their supramolecular interactions with DNA, possibly through modification of the surface morphology. These interactions can be exploited when developing carriers for gene therapy and theranostics. The resultant constructs are expected to be highly biocompatible due to their neutral potential and biodegradability of polyurea shells.

scholarly journals Calix[4]arene-Based MOFs Controlled by Length of Alkyldiammonium Guests

2014 ◽  
Vol 70 (a1) ◽  
pp. C1713-C1713
Author(s):  
Ki-Min Park ◽  
Eunji Lee ◽  
Huiyeong Ju ◽  
Suk-Hee Moon ◽  
Shim Sung Lee
Keyword(s):  
Electrostatic Interactions ◽  
Three Dimensional ◽  
Van Der Waals Interactions ◽  
Supramolecular Interactions ◽  
Solvothermal Reaction ◽  
Guest Molecules ◽  
Structural Framework ◽  
Guest Species ◽  
Dimensional Network ◽  
Alternative Conformation

Our interest in the development of MOFs with the cavities controlled by guest species has led us to investigate the MOFs based on calix[4]arene derivatives, in which metal ions link the calix unit to give the networks with the cavities accommodating several guest species, because the calix[4]arene-based MOFs contain porosity associated with both the ligand itself and the structural framework. In the present work, we employed a low rim-functionalized calix[4]arene tetraacetic acid (H4CTA) with 1,3-alternative conformation as a multidentate building block and alkyldiamines as the guest molecules. In the solvothermal reaction of H4CTA and Zn(II) ion in the presence of alkyldiamines, two types of new MOFs based on calix[4]arene tetraacetate (CTA4-) depending on the lengths of α,ω–alkyldiammonium guests have been synthesized by including suitable alkyldiammonium guests. Their single-crystal X-ray diffraction analyses reveal that the short alkyldiammonium guests such as ethyldiammonium, propyldiammonium, and butyldiammonium lead to form two-dimensional framework with the cavity consisting of two CTA4-and four Zn(II) ions whereas the alkyldiammonium guests such as heptyldiammonium, octyldiammonium, nonyldiammonium, and decyldiammonium give rise to generate three-dimensional network with the cavity surrounded by six CTA4-and four Zn(II) ions. The alkyldiammonium guests in both MOFs are well accommodated by each cavity via a variety of supramolecular interactions including electrostatic interactions, hydrogen bonds and van der Waals interactions. We will present and discuss a study on the syntheses and characterization of two new MOFs based on calix[4]arene derivative.

scholarly journals Mechanisms and Frequency of Resistance to Premafloxacin in Staphylococcus aureus: Novel Mutations Suggest Novel Drug-Target Interactions

2000 ◽  
Vol 44 (12) ◽  
pp. 3344-3350 ◽  
Author(s):  
Dilek Ince ◽  
David C. Hooper
Keyword(s):  
Staphylococcus Aureus ◽  
Fold Increase ◽  
Single Step ◽  
The Novel ◽  
Novel Mutations ◽  
Topoisomerase Iv ◽  
Double Mutation ◽  
Fourfold Increase ◽  
Novel Drug

ABSTRACT Premafloxacin is a novel 8-methoxy fluoroquinolone with enhanced activity against Staphylococcus aureus. We found premafloxacin to be 32-fold more active than ciprofloxacin against wild-type S. aureus. Single mutations in either subunit of topoisomerase IV caused a four- to eightfold increase in the MICs of both quinolones. A double mutation (gyrA and eithergrlA or grlB) caused a 32-fold increase in the MIC of premafloxacin, while the MIC of ciprofloxacin increased 128-fold. Premafloxacin appeared to be a poor substrate for NorA, with NorA overexpression causing an increase of twofold or less in the MIC of premafloxacin in comparison to a fourfold increase in the MIC of ciprofloxacin. The frequency of selection of resistant mutants was 6.4 × 10−10 to 4.0 × 10−7 at twofold the MIC of premafloxacin, 2 to 4 log10 less than that with ciprofloxacin. Single-step mutants could not be selected at higher concentrations of premafloxacin. In five single-step mutants, only one previously described uncommon mutation (Ala116Glu), and four novel mutations (Arg43Cys, Asp69Tyr, Ala176Thr, and Pro157Leu), three of which were outside the quinolone resistance-determining region (QRDR) were found. Genetic linkage studies, in which incross ofgrlA + and outcross of mutations were performed, showed a high correlation between the mutations and the resistance phenotypes, and allelic exchange experiments confirmed the role of the novel mutations in grlA in resistance. Our results suggest that although topoisomerase IV is the primary target of premafloxacin, premafloxacin appears to interact with topoisomerase IV in a manner different from that of other quinolones and that the range of the QRDR of grlA should be expanded.

scholarly journals Improving the Cellular Uptake of Biomimetic Magnetic Nanoparticles

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 766
Author(s):  
Federica Vurro ◽  
Ylenia Jabalera ◽  
Silvia Mannucci ◽  
Giulia Glorani ◽  
Alberto Sola-Leyva ◽  
...  
Keyword(s):  
Magnetic Nanoparticles ◽  
Electrostatic Interactions ◽  
Ph Value ◽  
Cell Uptake ◽  
The Novel ◽  
Tat Peptide ◽  
Ph Values ◽  
Cell Internalization ◽  
Drug Nanocarriers

Magnetococcus marinus magnetosome-associated protein MamC, expressed as recombinant, has been proven to mediate the formation of novel biomimetic magnetic nanoparticles (BMNPs) that are successful drug nanocarriers for targeted chemotherapy and hyperthermia agents. These BMNPs present several advantages over inorganic magnetic nanoparticles, such as larger sizes that allow the former to have larger magnetic moment per particle, and an isoelectric point at acidic pH values, which allows both the stable functionalization of BMNPs at physiological pH value and the molecule release at acidic (tumor) environments, simply based on electrostatic interactions. However, difficulties for BMNPs cell internalization still hold back the efficiency of these nanoparticles as drug nanocarriers and hyperthermia agents. In the present study we explore the enhanced BMNPs internalization following upon their encapsulation by poly (lactic-co-glycolic) acid (PLGA), a Food and Drug Administration (FDA) approved molecule. Internalization is further optimized by the functionalization of the nanoformulation with the cell-penetrating TAT peptide (TATp). Our results evidence that cells treated with the nanoformulation [TAT-PLGA(BMNPs)] show up to 80% more iron internalized (after 72 h) compared to that of cells treated with BMNPs (40%), without any significant decrease in cell viability. This nanoformulation showing optimal internalization is further characterized. In particular, the present manuscript demonstrates that neither its magnetic properties nor its performance as a hyperthermia agent are significantly altered due to the encapsulation. In vitro experiments demonstrate that, following upon the application of an alternating magnetic field on U87MG cells treated with BMNPs and TAT-PLGA(BMNPs), the cytotoxic effect of BMNPs was not affected by the TAT-PLGA enveloping. Based on that, difficulties shown in previous studies related to poor cell uptake of BMNPs can be overcome by the novel nanoassembly described here.

scholarly journals Adamantane-Functionalized Phthalimide Scaffold: Pathways to Supramolecular Interactions and Drug Discovery

Organics ◽  
2021 ◽  
Vol 2 (4) ◽  
pp. 388-394
Author(s):  
Hamidou Keita
Keyword(s):  
Crystal Structure ◽  
Drug Discovery ◽  
Single Crystal ◽  
Benzene Ring ◽  
Driving Force ◽  
Core Structure ◽  
Supramolecular Interactions ◽  
The Novel ◽  
X Ray ◽  
X Ray Crystallography

Herein, the synthesis of a novel adamantanyl-functionalized phthalimide scaffold is demonstrated. The novel compound could be used as a precursor for various synthetic pathways owing to the generic use of adamantane substituents as the driving force for supramolecular interactions with macrocycles and N-substituted phthalimide derivatives as a core structure in numerous drugs. The adamantanyl-functionalized phthalimide scaffold contains bromide groups on the C4 and C5 positions of the benzene ring, effectively allowing further facile modifications of the scaffold. The structure was fully characterized including single-crystal X-ray crystallography. The crystal structure shows an adamantane moiety at an angle of 115.57(7)° to the phthalimide core, hence sterically freeing the adamantane unit for host–guest interactions.

Oil-in-water emulsions stabilized by sodium alginate microgels

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Yuehan Wu ◽  
Meng Hu ◽  
Fangfang Chen ◽  
Chao Zhang ◽  
Zhiming Gao ◽  
...  
Keyword(s):  
Interfacial Tension ◽  
Sodium Alginate ◽  
Surface Hydrophobicity ◽  
Acidic Environment ◽  
The Novel ◽  
Water Emulsion ◽  
Oil In Water ◽  
New Strategy ◽  
Emulsifying Capacity ◽  
Oil In Water Emulsion

Abstract In this research, sodium alginate (ALG) microgels were prepared with different ALG concentrations, and physicochemical and emulsifying profiles of these hydrophilic microgels were comparatively analyzed. Results showed that these microgels possessed different size, hardness, and surface charge. All these microgels could stabilize an oil-in-water emulsion through the Mickering mechanisms, and smaller microgels had better emulsifying capacity. The surface hydrophobicity and interfacial tension of the microgels had no exact effects on their emulsifying behaviors. Compared with the harder microgels (prepared with high ALG concentration, e. g. 4 mg/mL), the emulsifying capacities of the softer ones (prepared with low ALG concentration, e.g. 1 mg/mL) were more sensitive to the high salt concentration (200 mM NaCl) but stable under acidic environment (pH 2.0). Our research would afford a new strategy for the manufacture and application of the novel polysaccharide-based emulsifiers.

Interaction of GelRed™ with single-stranded DNA oligonucleotides: Preferential binding to thymine-rich sequences

2021 ◽  
Vol 188 ◽  
pp. 109209
Author(s):  
Ryan J. Sapia ◽  
Colin Campbell ◽  
Adam J. Reed ◽  
Vladimir B. Tsvetkov ◽  
Yulia V. Gerasimova
Keyword(s):  
Single Stranded Dna ◽  
Dna Oligonucleotides ◽  
Preferential Binding

scholarly journals Polymer-mediated ternary supramolecular interactions for sensitive detection of peptides

The Analyst ◽  
2017 ◽  
Vol 142 (1) ◽  
pp. 118-122 ◽  
Author(s):  
Mahalia A. C. Serrano ◽  
Huan He ◽  
Bo Zhao ◽  
Rajasekhar R. Ramireddy ◽  
Richard W. Vachet ◽  
...  
Keyword(s):  
Electrostatic Interactions ◽  
Sensitive Detection ◽  
Supramolecular Interactions ◽  
Supramolecular System ◽  
Donor Acceptor

A combination of donor–acceptor and electrostatic interactions in a three-component supramolecular system has been shown to form the basis for selective and sensitive detection of peptides.

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