scholarly journals PEG-Modified tert-Octylcalix[8]arenes as Drug Delivery Nanocarriers of Silibinin

Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2025
Author(s):  
Desislava Budurova ◽  
Denitsa Momekova ◽  
Georgi Momekov ◽  
Pavletta Shestakova ◽  
Hristo Penchev ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Therapeutic Potential ◽  
Human Tumor ◽  
Aqueous Solubility ◽  
Present Contribution ◽  
Human Tumor Cell Lines ◽  
Non Covalent Interactions ◽  
Instrumental Methods ◽  
Supramolecular Aggregates ◽  
Covalent Interactions

The hepatoprotective properties of silibinin, as well its therapeutic potential as an anticancer and chemo-preventive agent, have failed to progress towards clinical development and commercialization due to this material’s unfavorable pharmacokinetics and physicochemical properties, low aqueous solubility, and chemical instability. The present contribution is focused on the feasibility of using PEGylated calixarene, in particular polyoxyethylene-derivatized tert-octylcalix[8]arene, to prepare various platforms for the delivery of silibinin, such as inclusion complexes and supramolecular aggregates thereof. The inclusion complex is characterized by various instrumental methods. At concentrations exceeding the critical micellization concentration of PEGylated calixarene, the tremendous solubility increment of silibinin is attributed to the additional solubilization and hydrophobic non-covalent interactions of the drug with supramolecular aggregates. PEG-modified tert-octylcalix[8]arenes, used as drug delivery carriers for silibinin, were additionally investigated for cytotoxicity against human tumor cell lines.

Delineating synchronized control of dynamic covalent and non-covalent interactions for polymer chain collapse towards cargo localization and delivery

2021 ◽  
Author(s):  
Jojo P Joseph ◽  
Chirag Miglani ◽  
Aashish Bhatt ◽  
Debes Ray ◽  
Ashmeet Singh ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Polymer Chain ◽  
Structural Control ◽  
Synthetic Polymers ◽  
Folding Process ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Synchronized Control

Chain collapse in synthetic polymers is an excellent approach to mimick natural self-folding process that imparts structural control leading to attractive compartmental applications e.g. drug delivery. In this regard, water...

scholarly journals Chitosan-Based Biocompatible Copolymers for Thermoresponsive Drug Delivery Systems: On the Development of a Standardization System

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1876
Author(s):  
Lorenzo Marsili ◽  
Michele Dal Bo ◽  
Federico Berti ◽  
Giuseppe Toffoli
Keyword(s):  
Drug Delivery ◽  
Biomedical Applications ◽  
Biological Tissues ◽  
Special Focus ◽  
Thermoresponsive Polymers ◽  
Basic Principles ◽  
Natural Polysaccharide ◽  
Non Covalent Interactions ◽  
Covalent Interactions ◽  
Or Applications

Chitosan is a natural polysaccharide that is considered to be biocompatible, biodegradable and non-toxic. The polymer has been used in drug delivery applications for its positive charge, which allows for adhesion with and recognition of biological tissues via non-covalent interactions. In recent times, chitosan has been used for the preparation of graft copolymers with thermoresponsive polymers such as poly-N-vinylcaprolactam (PNVCL) and poly-N-isopropylamide (PNIPAM), allowing the combination of the biodegradability of the natural polymer with the ability to respond to changes in temperature. Due to the growing interest in the utilization of thermoresponsive polymers in the biological context, it is necessary to increase the knowledge of the key principles of thermoresponsivity in order to obtain comparable results between different studies or applications. In the present review, we provide an overview of the basic principles of thermoresponsivity, as well as a description of the main polysaccharides and thermoresponsive materials, with a special focus on chitosan and poly-N-Vinyl caprolactam (PNVCL) and their biomedical applications.

9. pH Triggered Molecular Tweezers for Drug Delivery Applications

2016 ◽  
Author(s):  
Caitlin Miron
Keyword(s):  
Drug Delivery ◽  
Targeted Delivery ◽  
Chemical Potential ◽  
Cancer Drug ◽  
Molecular Tweezers ◽  
Binding Domains ◽  
Non Covalent Interactions ◽  
Molecular Tweezer ◽  
First Time ◽  
Covalent Interactions

Molecular tweezers are simple synthetic receptors that are generally composed of two binding domains connected by a spacer group. The non-covalent interactions that occur between the tweezer and its substrate are usually reversible, which facilitates the release of the bound substrate at a target site when triggered by a stimulus such as light, temperature, pH,] or change in chemical potential. In the field of cancer research, one strategy for targeting drug delivery relies on the pH drop in cancerous tissues compared to healthy tissues. We recently showed, for the first time, that it is possible to use pH to tune the binding affinity of molecular tweezers for substrates such as the cancer drug MitoxantroneTM. The molecular tweezer switches conformation from a closed (binding) state to an open (release) state upon acidification. As a result, the targeted delivery of MitoxantroneTM is achieved. This proof of concept shows that molecular tweezers are promising tools for selective drug delivery.

scholarly journals Columnar Aggregates of Azobenzene Stars: Exploring Intermolecular Interactions, Structure, and Stability in Atomistic Simulations

Molecules ◽  
2021 ◽  
Vol 26 (24) ◽  
pp. 7598
Author(s):  
Markus Koch ◽  
Marina Saphiannikova ◽  
Olga Guskova
Keyword(s):  
Hydrogen Bonds ◽  
Md Simulations ◽  
Binding Energies ◽  
Atomistic Simulations ◽  
Π Interactions ◽  
Different Types ◽  
Non Covalent Interactions ◽  
Experimental Works ◽  
Supramolecular Aggregates ◽  
Covalent Interactions

We present a simulation study of supramolecular aggregates formed by three-arm azobenzene (Azo) stars with a benzene-1,3,5-tricarboxamide (BTA) core in water. Previous experimental works by other research groups demonstrate that such Azo stars assemble into needle-like structures with light-responsive properties. Disregarding the response to light, we intend to characterize the equilibrium state of this system on the molecular scale. In particular, we aim to develop a thorough understanding of the binding mechanism between the molecules and analyze the structural properties of columnar stacks of Azo stars. Our study employs fully atomistic molecular dynamics (MD) simulations to model pre-assembled aggregates with various sizes and arrangements in water. In our detailed approach, we decompose the binding energies of the aggregates into the contributions due to the different types of non-covalent interactions and the contributions of the functional groups in the Azo stars. Initially, we investigate the origin and strength of the non-covalent interactions within a stacked dimer. Based on these findings, three arrangements of longer columnar stacks are prepared and equilibrated. We confirm that the binding energies of the stacks are mainly composed of π–π interactions between the conjugated parts of the molecules and hydrogen bonds formed between the stacked BTA cores. Our study quantifies the strength of these interactions and shows that the π–π interactions, especially between the Azo moieties, dominate the binding energies. We clarify that hydrogen bonds, which are predominant in BTA stacks, have only secondary energetic contributions in stacks of Azo stars but remain necessary stabilizers. Both types of interactions, π–π stacking and H-bonds, are required to maintain the columnar arrangement of the aggregates.

Advances in oral controlled drug delivery: the role of drug–polymer and interpolymer non-covalent interactions

2014 ◽  
Vol 12 (3) ◽  
pp. 441-453 ◽  
Author(s):  
Simona De Robertis ◽  
Maria Cristina Bonferoni ◽  
Lisa Elviri ◽  
Giuseppina Sandri ◽  
Carla Caramella ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Controlled Drug Delivery ◽  
Non Covalent Interactions ◽  
Covalent Interactions

scholarly journals Possibility of Complexation of the Calix[4]Arene Molecule with the Polluting Gases: DFT and NCI-RDG Theory

2020 ◽  
Author(s):  
Bouzid Gassoumi ◽  
Fatma Ezzahra Ben Mohamed ◽  
Houcine Ghalla ◽  
Rafik Ben Chaabane
Keyword(s):  
Drug Delivery ◽  
Binding Energies ◽  
Basis Set ◽  
Gaseous Pollutants ◽  
Sensitive Area ◽  
Basis Set Superposition Error ◽  
Pharmaceutical Drug ◽  
Pollution Problem ◽  
Non Covalent Interactions ◽  
Covalent Interactions

The calix[4]arenes (abbreviated as CX[4]) are characterized by a specific hydrophobic cavity formed by a four cyclically phenol groups to encapsulate a gas or small molecules. Recently, the CX[4] molecule is used in a specific media and in pharmaceutical drug delivery. The pollution problem will be a vital subject in the future because the increase of the explosions of the gaseous pollutants in the environment. In this report, we have encapsulated the polluting gases NO3, NO2, CO2 and N2 by the calix[4]arene molecule. In this work, The binding energies of the CX[4]-gas has been calculated including the BSSE (Basis Set Superposition Error) counterpoise (CP). The red-shift of the O-H bonding interactions obtained by adding the gas in the sensitive area of calix[4]arene is clearly explained by the infrared spectrum analysis. The Molecular electrostatic potential (MEP) of the stable CX[4]-gas complexes have been investigated in the endo-vs. exo-cavity regions. Finally, the non-covalent interactions analyses of the stable host-guests complexes have been estimated by using DFT calculations.

scholarly journals AN OVERVIEW OF THE PROMISING APPROACH TO ENHANCE THE PHYSICAL PROPERTY OF API BY PHARMACEUTICAL CO-CRYSTALLISATION TECHNIQUE

2020 ◽  
Vol 9 (4) ◽  
Author(s):  
Shiwangi Jain ◽  
Mayank Bansal
Keyword(s):  
Physical Property ◽  
Aqueous Solubility ◽  
Literature Survey ◽  
Production Methods ◽  
Neutral Compounds ◽  
Non Covalent Interactions ◽  
Key Aspects ◽  
Crystalline Complexes Of ◽  
Covalent Interactions ◽  
Ionisable Group

Co-crystals are defined as crystalline complexes of two or more neutral molecular constituents bound together in the crystal lattice through non covalent interactions. This article summarized about the co-crystal definition, its importance along with characterizations and screening and production methods. From the literature survey, it can be concluded that improvement of performance characteristics of APIs using co-crystallization is a shows potential approach. One of the key aspects of this technique is that it can be useful to all APIs affliction from poor aqueous solubility.  Co-crystallization moves toward is flourishing now adays due to its immaculate effect of solubility on poorly dissolvable drugs, especially those having weakly ionisable group and neutral compounds. Meanwhile co-crystallization will also put an effort into upgrading of other physicochemical properties of drugs such as chemical stability, flowability etc. Keywords: Co-crystals, characteristics, screening, productions, solubility

NON COVALENT INTERACTIONS IN LARGE DIAMONDOID DIMERS IN THE GAS PHASE - A MICROWAVE STUDY

2017 ◽  
Author(s):  
Cristobal Perez ◽  
Melanie Schnell ◽  
Peter Schreiner ◽  
Norbert Mitzel ◽  
Yury Vishnevskiy ◽  
...  
Keyword(s):  
Gas Phase ◽  
Non Covalent Interactions ◽  
Covalent Interactions
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