Reverse Micelles As Antioxidant Carriers: An Experimental and Molecular Dynamics Study

Abstract

Water-in-oil microemulsions with biocompatible components were formulated to be used as carriers of natural antioxidants, such as hydroxytyrosol (HT) and gallic acid (GA). The system was composed of a mixture of natural surfactants, lecithin and monoglycerides, medium chain triglycerides, and aqueous phase. A dual approach was undertaken to study the structure and dynamics of these complicated systems. First, experimental data were collected by using adequate techniques, such as dynamic light scattering (DLS) and electron paramagnetic resonance (EPR) spectroscopy. Following this, a coarse-grained molecular dynamics (CGMD) study based on the experimental composition using the MARTINI force field was conducted. The simulations revealed the spontaneous formation of reverse micelles (RMs) starting from completely random initial conformations, underlying their enhanced thermodynamic stability. The location of the bioactive molecules, as well as the structure of the RM, were in accordance with the experimental findings. Furthermore, GA molecules were found to be located inside the water core, in contrast to the HT ones, which seem to lie at the surfactant interfacial layer. The difference in the antioxidants' molecular location was only revealed in detail from the computational analysis and explains the RM's swelling observed by GA in DLS measurements.

Versatility of Reverse Micelles: From Biomimetic Models to Nano (Bio)Sensor Design

“…RMs formed with nonionic surfactants have extreme sensitivity to the process conditions and, therefore, are less characterized [10,41]. However, different surfactants from the Tween, Triton (e.g., Triton X-100, polyoxyethylene(10)isooctylphenyl ether), Brij (e.g., Brij30, polyoxyethylene(4) lauryl ether), and Span series, as well as Igepal CO520 or various mixtures of polyoxyethylene(5) nonylphenol ether (NP-5), polyoxyethylene(9) nonylphenol ether (NP-9), and polyoxyethylene (12) nonylphenol ether (NP-12), have been used in various studies [41,47,48].…”

“…have been proposed. Many well-documented reviews and comprehensive books have been published during the years of study, including the latest ones approaching the assessment of current knowledge and dealing with several aspects of reverse micelles [7][8][9][10][11][12][13].…”

Wedelolactone-Loaded Micelles Ameliorate Doxorubicin-Induced Oxidative Injury in Podocytes by Improving Permeability and Bioavailability

“…The in vivo behavior and bioavailability of these compounds could be influenced by both physicochemical and physiological factors (Upadhyay et al, 2012). WED, a naturally occurring coumestan, has poor absorption through the intestine (Chatzidaki et al, 2017). In the present study, the drug delivery system of WED-M was developed by encapsulating Solutol ® HS15 and lecithin, which could improve the water solubility and bioavailability of WED.…”

Biocompatible Solvents and Ionic Liquid-Based Surfactants as Sustainable Components to Formulate Environmentally Friendly Organized Systems

“…RMs composed of MCTs as the oil phase, lecithin, and monoglycerides as surfactants, and an aqueous phase were formulated to be used as carriers of natural antioxidants, such as HT and GA [ 99 ]. Thus, RMs composed of triglycerides (caprylic/capric) as the oil phase and lecithin and monoglycerides of vegetable fatty acids (DMG 0295) as surfactants were characterized by DLS and EPR.…”