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 ◽  
...  

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...

Pharmaceutics ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1876
Author(s):  
Lorenzo Marsili ◽  
Michele Dal Bo ◽  
Federico Berti ◽  
Giuseppe Toffoli

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.


Author(s):  
Caitlin Miron

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.


2014 ◽  
Vol 12 (3) ◽  
pp. 441-453 ◽  
Author(s):  
Simona De Robertis ◽  
Maria Cristina Bonferoni ◽  
Lisa Elviri ◽  
Giuseppina Sandri ◽  
Carla Caramella ◽  
...  

2020 ◽  
Author(s):  
Bouzid Gassoumi ◽  
Fatma Ezzahra Ben Mohamed ◽  
Houcine Ghalla ◽  
Rafik Ben Chaabane

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.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (12) ◽  
pp. 2025
Author(s):  
Desislava Budurova ◽  
Denitsa Momekova ◽  
Georgi Momekov ◽  
Pavletta Shestakova ◽  
Hristo Penchev ◽  
...  

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.


Author(s):  
Cristobal Perez ◽  
Melanie Schnell ◽  
Peter Schreiner ◽  
Norbert Mitzel ◽  
Yury Vishnevskiy ◽  
...  

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