Relevance of charges and polymer mechanical stiffness in the mechanism and kinetics of formation of liponanoparticles probed by the supported bilayer model approach

Abstract

Parameters controlling the mechanism and kinetics of formation of liponanoparticles are determined using supported lipid bilayer models.

Hybrid Lipid Polymer Nanoparticles for Combined Chemo- and Photodynamic Therapy

“…LNPs contain three compartments, namely, the NP core, a thin water layer and the lipid bilayer. The thickness of the water layer has been measured by various authors, using lipid bilayers formed on planar and spherical supports, and different techniques such as neutron reflectivity or 1 H NMR. − It was found in the 0.6–3 nm range. − The thickness of a bilayer adsorbed to a PDLLA layer, as deduced from atomic force microscopy height pictures, was 3.9 ± 0.4 nm. ,− Therefore, we expected an increase in the particle size of about 12 nm corresponding to 2­[lipid bilayer thickness + water layer], compared to PDLLA NPs.…”

“…The highest content of lipid observed for LNP 90/10 is coherent with cryo-TEM images which showed that at 10% DOTAP, the NP surface was covered with intact vesicles. Increase in cationic lipid content resulted in a stronger electrostatic interaction between vesicles and particles, followed by vesicle breaking and fusion to form a lipid bilayer. , The ratio of DOTAP in the LNP shell increased with the initial amount of DOTAP added to the formulation: 17, 35, and 58 mol % instead of 10, 25.5, and 46.5 mol % in corresponding liposomes. This result agreed with expectations because DOTAP would preferentially adsorb to the negatively charged NP surface compared to POPC. ,, The equivalent number of lipid bilayers was estimated by assuming that a lipid bilayer fully covering the NPs had a total surface area ( A v ) equal to that of the NPs (i.e., A v / A p = 1) .…”

“…LNPs were formed according to the protocol described by Thevenot et al, , with modification . Liposomes in excess were added to nanoparticles and the mixture was sonicated for 6 min, then incubated for 1 h at room temperature.…”

“…Poly (D,L)lactic acid (PDLLA) nanoparticles (PDLLA NPs) were prepared by the nanoprecipitation method without using a surfactant. 54 Briefly, PDLLA (50 mg) was dissolved in acetone to achieve a polymer concentration of 10 mg/mL. This solution was added dropwise to ultrapure water under moderate magnetic stirring.…”

“…LNPs were formed via electrostatic interactions between oppositely charged vesicles and nanoparticles. , We chose the biocompatible and biodegradable poly­( d , l -lactic)­acid (PDLLA) for the LNP core, and a mixture of zwitterionic and cationic lipids [1,2-dioleoyl-3-trimethylammonium-propane (POPC) and 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP)], for the lipid shell. We studied the typical characteristics of the LNPs, their stability in the cell culture medium, the conditions for preserving the efficacy of co-encapsulated m -THPC and β-Lap, and their combinatorial efficacy when injected in RB cell suspensions.…”