Structurally Stable Attractive Nanoscale Emulsions with Dipole–Dipole Interaction‐Driven Interdrop Percolation

Abstract

This study introduces an extremely stable attractive nanoscale emulsion fluid, in which the amphiphilic block copolymer, poly(ethylene oxide)-block-poly(ϵ-caprolactone) (PEO-b-PCL), is tightly packed with lecithin, thereby forming a mechanically robust thin-film at the oil-water interface. The molecular association of PEO-b-PCL with lecithin is critical for formation of a tighter and denser molecular assembly at the interface, which is systematically confirmed by T relaxation and DSC analyses. Moreover, suspension rheology studies also reflect the interdroplet attractions over a wide volume fraction range of the dispersed oil phase; this results in a percolated network of stable drops that exhibit no signs of coalescence or phase separation. This unique rheological behavior is attributed to the dipolar interaction between the phosphorylcholine groups of lecithin and the methoxy end groups of PEO-b-PCL. Finally, the nanoemulsion system significantly enhances transdermal delivery efficiency due to its favorable attraction to the skin, as well as high diffusivity of the nanoscale emulsion drops.

Nanoemulsion Vehicles as Carriers for Follicular Delivery of Luteolin

“…The phase inversion composition method has been shown to enable effective assembly of such a polymer membrane . In fact, coassembly of a critical concentration of lecithin with PEO- b -PCL not only made the interface tightly packed but also enhanced skin permeability . Luteolin-loaded nanoemulsions were characterized by DLS (Figures B and C).…”

“…Here in this study, we introduce a nanoemulsion-based follicular delivery system, in which luteolin, a well-known flavonoid, is incorporated into O/W nanoemulsions, and its hair-growth promotion ability is evaluated in vivo. Stable luteolin-loaded nanoemulsions were prepared by the assembly of poly­(ethylene oxide)- block -poly­(ε-caprolactone) (PEO- b -PCL) and lecithin at the O/W interface . This emulsification method is based on an attractive nanoemulsion fluid system with a drop-percolated network, in which dipole–dipole interaction between phosphorylcholine groups of lecithin and methoxy end groups of poly­(ethylene oxide)- block -poly­(ε-caprolactone) leads to a gel-like rheological behavior.…”

Two-dimensional demixing within multilayered nanoemulsion films

“…Two types of cutoff distances ( r c ) for the LJ potential were selected: r c = 2.5σ for the standard LJ potential and rc=26normalσ for the fully repulsive Weeks-Chandler-Anderson (WCA) potential ( 36 ). The values of the potential parameter ε of the LJ potential for all possible pairs of systems are listed in table S1.…”

Cell-Penetrating Peptide-Patchy Deformable Polymeric Nanovehicles with Enhanced Cellular Uptake and Transdermal Delivery

“…A confocal Raman spectroscopy setup was conducted for evaluation of in vivo transdermal delivery performance in a manner similar to that previously reported. 11 The topical delivery experiments were performed on the volar forearms of four female subjects with age ranging from 24…”

“…Transdermal delivery is a method of administering active ingredients through the skin. , For the target active drugs to penetrate deeply into the skin, the barrier functions of the stratum corneum must be overcome. In terms of skin safety and delivery efficiency, one of the reasonably accessible transdermal delivery systems involves the use of nanosized carriers designed using amphiphiles, including biocompatible surfactants, − lipids, − and biopolymers. − To maximize the diffusivity of carriers through the skin layers, the particle size should be controlled within the range of nanometer length scales . In addition, in order for drug carriers to pass through the intercellular lipid membrane, it is important that they have a deformable or fluidizable phase .…”