Selenium-capped cyclic peptide nanoparticles for penicillamine drug delivery: A DFT Study

43-50Using a model for performance of penicillamine (PCA) anti-cancer drug on selenium-cyclic peptide nanoparticle (CPSeNP), 11 noncovalent configurations have been investigated. Se8 ring model and cyclooctaglycine have been used for selenium nanoparticle (SeNP) and cyclic peptide (CP), respectively. Binding energies, quantum molecular descriptors and solvation energies have been studied in gas phase and water at M06-2X /6-31G** level of theory. The calculated energies represent the high-energy stability of CPSeNP/PCA 1-11 configurations. Solvation energies showed that drug solubility increases, which is a major factor for their use in drug delivery. Regarding to quantum molecular descriptors such as hardness and electrophilic power, the drug reactivity increases in the vicinity of SeNP. The QTAIM analysis revealed that intramolecular interaction Se-L (L =O, H , S, C , N) plays an important role in the system. Se-L interaction in all configurations is relevant to weak interactions. The configurations that PCA drug is located in parallel with the carrier (CPSeNP) are more stable than penicillamine-CP or penicillamine-SeNP systems

Magnetized Chitosan Hydrogel and Silk Fibroin, Reinforced with PVA: A Novel Nanobiocomposite for Biomedical and Hyperthermia Applications

Herein, a multifunctional nanobiocomposite was designed for biological application, amongst which hyperthermia cancer therapy application was specifically investigated. This nanobiocomposite was fabricated based on chitosan hydrogel (CS), silk fibroin (SF), water-soluble polymer polyvinyl alcohol (PVA) and iron oxide magnetic nanoparticles (Fe3O4 MNPs). CS and SF as natural compounds were used to improve the biocompatibility, biodegradability, adhesion and cell growth properties of the nanobiocomposite that can prepare this nanocomposite for the other biological applications such as wound healing and tissue engineering. Since the mechanical properties are very important in biological applications, PVA polymer was used to increase the mechanical properties of the prepared nanobiocomposite. All components of this nanobiocomposite have good dispersion in water due to the presence of hydrophilic groups such as NH2, OH, and COOH, which is one of the effective factors in increasing the efficiency of hyperthermia cancer therapy. The structural analyzes of the hybrid nanobiocomposite were determined by FT-IR, XRD, EDX, FE-SEM, TGA and VSM. Biological studies such as MTT and hemolysis testing proved that it is hemocompatible and non-toxic for healthy cells. Furthermore, it can cause the death of cancer cells to some extent (20.23%). The ability of the nanobiocomposites in hyperthermia cancer therapy was evaluated. Also, the results showed that it can be introduced as an excellent candidate for hyperthermia cancer therapy

Microwave-assisted deoximation under solvent-free conditions using Bi(NO₃)₃.5H₂O supported onto montmorillonite K-10<b style=""></b>

831-833Oximes are oxidatively deprotected by bismuth nitrate supported onto montmorillonite K-10 to the parent carbonyl compound in high yields upon exposure to microwave irradiation in solventless system

Wet alumina supported 3-carboxypyridinium chlorochromate selective oxidation of alcohols in solventless system

436-437A simple and selective method for the oxidation of alcohols to carbonyl compounds is described that occurs on alumina supported 3-carboxypyridinium chlorochromate (CPCC) under solvent -free conditions and is expedited by microwave irradiation

DFT STUDY ON THE MECHANISTIC, ENERGETIC AND STRUCTURAL ASPECTS OF ADSORPTION OF TIRAPAZAMINE ONTO PRISTINE AND FUNCTIONALIZED CARBON NANOTUBES

Using density functional theory, noncovalent interactions and two mechanisms of covalent functionalization of drug tirapazamine with pristine, COOH and COCl functionalized carbon nanotube (NT, NTCOOH and NTCOCl) have been investigated. Quantum molecular descriptors of noncovalent configurations were studied. It was specified that binding of drug tirapazamine with NTCOOH has more binding energy than NTCOCl and NT, so NTCOOH can act as a favorable system for tirapazamine drug delivery within biological and chemical systems (noncovalent). NTCOOH and NTCOCl can bond to the amino group of tirapazamine through OH (COOH mechanism) and Cl (COCl mechanism) groups, respectively. The activation parameters of two pathways were calculated and compared with each other. The activation parameters related to COOH mechanism are higher than those related to COCl mechanism and therefore COCl mechanism is suitable for covalent functionalization. These results could be generalized to other similar drugs