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

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

Design of octopus-shaped macromolecules based on tertbutylcalix[4]arenes as drug delivery platforms for curcumin

Water-soluble calixarenes are promising macrocyclic compounds which have found numerous applications in chemistry and biology. Due to their ability to form inclusion complexes and to accommodate various substances, the calix[n]arenes are considered promising versatile drug delivery platforms. However their drug solubilizing properties and applicability as drug delivery systems so far have not been explored in detail. The present work is aimed at exploration of octopus-shaped polyoxyethylated tert-butylcalix[4]arenes (PEG-CX-4) as a drug delivery platform for the lipophilic agent curcumin

Liposomal formulations for delivery of curcumin-pegylated calix[n]arenes inclusion complexes

Curcumin, the constituent of Curcuma longa, is considered a very promising anticancer agent due to its potent and pleiotropic antineoplastic activity and low nonspecific toxicity to normal cells. However the clinical realization of its potential has been limited due to its poor aqueous solubility and very low systemic bioavailability. A possible aproach to overcome these limitations is the design of nanosized vechicles of curcumin. The present work reports the preparation, characterization and in vitro evaluation of antineoplastic activity of novel curcumin-in pegylated calix[4]arenes – in liposomes nanoparticle

Polybenzimidazole-Graft-Polyvinylphosphonic Acid—Proton Conducting Fuel Cell Membranes

A new method for the preparation of polybenzimidazole (PBI)-based membranes, containing high concentrations of immobilized phosphonic acid groups, has been developed. The procedure used is carried out in two steps: (1) Synthesis of modified PBIs, containing 1,2-dihydroxypropyl groups and preparation of films there from; (2) Introduction of vinylphosphonic acid (VPA) and initiator (cerium ammonium nitrate) in the film, subsequent grafting of VPA from the active sites of the PBI backbone. Membranes with different length of the grafted polyvinylphosphonic acid chains were prepared. The molar ratio grafted VPA units per PBI repeating unit reaches 7.8. Proton conductivity was measured at 120C and relative humidity (RH) 20–100%. For the membrane with highest concentration of phosphonic acid groups the proton conductivity was 35 mS cm1 at 100% RH and 8 mS cm1 at 20% RH.JRC.F.2-Cleaner energ

PEG-Modified <i>tert</i>-Octylcalix[8]arenes as Drug Delivery Nanocarriers of Silibinin

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

Preparation and characterization of liposomal-pegilated calix[4]arenes nanoparticles as drug delivery systems for curcumin

Curcumin, the constituent of Curcuma longa, is considered a very promising anticancer agent due to its potent and pleiotropic antineoplastic activity and low nonspecific toxicity to normal cells (1). However the clinical realization of its potential has been limited due to its poor aqueous solubility (11ng/ml) and very low systemic bioavailability. A possible aproach to overcome these limitations is the design of nanosized vechicles of curcumin. The present work reports the preparation, characterization and in vitro evaluation of antineoplastic activity of curcumin loaded calixarenes-in liposomes nanoparticles

Nanocomposite Perfluorosulfonic Acid/Montmorillonite-Na⁺ Polymer Membrane as Gel Electrolyte in Hybrid Supercapacitors

Solid-state supercapacitors with gel electrolytes have emerged as a promising field for various energy storage applications, including electronic devices, electric vehicles, and mobile phones. In this study, nanocomposite gel membranes were fabricated using the solution casting method with perfluorosulfonic acid (PFSA) ionomer dispersion, both with and without the incorporation of 10 wt.% montmorillonite (MMT). MMT, a natural clay known for its high surface area and layered structure, is expected to enhance the properties of supercapacitor systems. Manganese oxide, selected for its pseudocapacitive behavior in a neutral electrolyte, was synthesized via direct co-precipitation. The materials underwent structural and morphological characterization. For electrochemical evaluation, a two-electrode Swagelok cell was employed, featuring a carbon xerogel negative electrode, a manganese dioxide positive electrode, and a PFSA polymer membrane serving as both the electrolyte and separator. The membrane was immersed in a 1 M Na2SO4 solution before testing. A comprehensive electrochemical analysis of the hybrid cells was conducted and compared with a symmetric carbon/carbon supercapacitor. Cyclic voltammetric curves were recorded, and galvanostatic charge–discharge tests were conducted at various temperatures (20, 40, 60 °C). The hybrid cell with the PFSA/MMT 10 wt.% exhibited the highest specific capacitance and maintained its hybrid profile after prolonged cycling at elevated temperatures, highlighting the potential of the newly developed membrane

Aggregation behavior and in vitro biocompatibility study of octopus-shaped macromolecules based on tert-butylcalix[4]arenes

A series of products based on tert-butylcalix[4]arene have been synthesized by anionic polymerization of ethylene oxide. The resulting products are amphiphilic octopus-shaped macromolecules, consisting of a hydrophobic calix[4]arene core and four arms of hydrophilic poly(ethylene oxide) chains. In aqueous solutions the polyoxyethylated tert-butylcalix[4]arenes were found to self-associate above certain CMC determined by dye solubilization technique. The light scattering study reveals that the polyoxyethylated tert-butylcalix[4]arenes form aggregates of narrow size distribution and hydrodynamic diameters ranging from about 155 to 245 nm and aggregation numbers from tens to hundreds macromolecules per particle depending on the degree of polymerization of the PEO chains. An in vitro biocompatibility study showed that the tested compounds are practically devoid of intrinsic cytotoxic and hemolytic effects and moreover they failed to modulate the mitogen-induced interleukin-2 release from the human T-lymphocyte cell line Jurkat E6-1. Taken together the excellent in vitro biocompatibility profile and the favorable physicochemical characteristics of the tested polyoxyethylated calix[4]arenes give us reason to consider them as promising for further evaluation as drug delivery platforms

Hybrid liposomal PEGylated calix[4]arene systems as drug delivery platforms for curcumin

The tremendous therapeutic potential of curcumin as a chemopreventive, antineoplastic and chemosensitizing agent has failed to progress towards clinical development and commercialization due to its unfavorable physicochemical properties, low aqueous solubility, chemical instability, and pharmacokinetics. The present contribution is focused on the feasibility of using PEGylated calixarene, in particular polyoxyethylene-derivatized tert-butylcalix[4]arene, to prepare various platforms for delivery of curcumin such as inclusion complex, supramolecular aggregates, and hybrid liposomal systems. The inclusion complex is characterized by UV–vis and FT-IR spectroscopy as well as thermal gravimetrical analysis and differential scanning calorimetry. At concentrations exceeding the critical micellization concentration of PEGylated calixarene, the tremendous solubility enhancement of curcumin is attributed to additional solubilization and hydrophobic non-covalent interactions of the drug with supramolecular aggregates. A hybrid liposomal system is created via encapsulation of the inclusion complex in dipalmitoylphosphatidylcholine:cholesterol liposomes. Bare and liposomal curcumin:BEC-X inclusion complexes, as well as free curcumin were additionally investigated for cytotoxicity and apoptogenic activity against human tumor cell lines