Molecular dynamics (MD) simulation using the AMBER force field has been performed on the neurotensin (NT) receptor, a class A type G-protein-coupled receptor in its activated conformation co-crystallized with the non-peptide agonists. For structure-based hit molecule identification via natural chemical compound library, orthosteric sites on NT receptor have been mapped by docking using AutoDock4.0 and Vina with the known agonists and antagonists SR48692, SR142948, ML301 and ML314 of the receptor.
View Article and Find Full Text PDFIn this report we assessed by docking and molecular dynamics the binding mechanisms of three FDA-approved Alzheimer drugs, inhibitors of the enzyme acetylcholinesterase (AChE): donepezil, galantamine and rivastigmine. Dockings by the softwares Autodock-Vina, PatchDock and Plant reproduced the docked conformations of the inhibitor-enzyme complexes within 2Å of RMSD of the X-ray structure. Free-energy scores show strong affinity of the inhibitors for the enzyme binding pocket.
View Article and Find Full Text PDFRecent advances in theory of solid state nuclear magnetic resonance (NMR) such as Floquet-Magnus expansion and Fer expansion, address alternative methods for solving a time-dependent linear differential equation which is a central problem in quantum physics in general and solid-state NMR in particular. The power and the salient features of these theoretical approaches that are helpful to describe the time evolution of the spin system at all times are presented. This review article presents a broad view of manipulations of spin systems in solid-state NMR, based on milestones theories including the average Hamiltonian theory and the Floquet theory, and the approaches currently developing such as the Floquet-Magnus expansion and the Fer expansion.
View Article and Find Full Text PDFExpert Opin Drug Metab Toxicol
October 2016
Introduction: Drug resistance is the major obstacle impeding the efficacy of chemotherapeutic agents. Although numerous drug delivery techniques have been developed to combat drug resistance, their limitations of non-specific targeting and inconsistent bioavailability has led to the search of novel delivering strategies, such as nanoparticles.
Areas Covered: Nanoparticles for anti-cancer drug delivery are microscopic preparations encapsulating a chemotherapeutic and a chemosensitizer into a rationally designed drug delivery vehicle.
Purpose: To establish the biodistribution profile of the PLGA nanoparticles with dual surface modifications of PEG and folic acid (FA) in mice xenografted with MDA-MB-231 human breast cancer cells with high expression of folate receptor (FR); and to illustrate that the modified nanoparticles can target the loaded indocyanine green (ICG) to the tumor with high FR expression.
Methods: ICG-loaded nanoparticles were prepared with PLGA (non-modified nanoparticles, NM-NP) or mPEG-PLGA and FA-PLGA (dual modified nanoparticles, DM-NP). Biodistribution of the ICG-loaded nanoparticles (1.
The objective of this study is to investigate the biodistribution of Indocyanine green (ICG) in healthy mice, when delivered through polymeric nanoparticles. The poly(DL-lactic-co-glycolic acid) (PLGA) nanoparticles entrapping ICG were engineered and characterized. The extraction method for ICG recovery from biological samples was developed.
View Article and Find Full Text PDFPurpose: The objective of this study is to develop indocyanine green (ICG)-loaded biodegradable nanoparticles by using biodegradable polymer, poly(DL-lactic-co-glycolic acid) (PLGA).
Method: PLGA nanoparticles entrapping ICG were prepared by a modified spontaneous emulsification solvent diffusion method. To optimize the nanoparticle formulation, the influence of formulation parameters such as types of ICG, amount of ICG and the polymer were investigated.
Photo-degradation, thermal-degradation and aqueous-instability of indocyanine green (ICG) limits its application as a fluorescence contrast agent for imaging purposes. Thus, the objective of this study is to develop polymeric nanoparticles entrapping ICG and to establish its effectiveness in providing photo-stability, thermal stability and aqueous stability to ICG. Nanoparticles entrapping ICG were engineered, characterized and the degradation kinetics of ICG in the nanoparticles was investigated in aqueous media.
View Article and Find Full Text PDFThe degradation kinetics of a near-infrared fluorescent, diagnostic, and photodynamic agent, indocyanine green (ICG), was investigated in aqueous solution by steady-state fluorescence technique. The influence of ICG concentration on its fluorescence spectrum was determined. The degradation kinetics of ICG in aqueous solution was studied as a function of light exposure, type of light exposed, temperature, and ICG concentration.
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