New sight at the organization of layers of multilayer polyelectrolyte microcapsules

Abstract

In this work, the mutual arrangement of polyelectrolytes of multilayer polyelectrolyte microcapsules (with layers—[PAH/PSS]3PAH) by determination of the dissociation level of polyallylamine (PAH) from the surface of a polyelectrolyte microcapsules (PMC) of various types was studied: PMC with a dissolved CaCO3 core after preparation, PMC with an undissolved CaCO3 core and PMC with an encapsulated protein. It was concluded that the polyelectrolyte layers are mixed in the entire shell of the capsules with a dissolved CaCO3 core. In the case of the PMC with an undissolved CaCO3 core, such mixing of polyelectrolyte layers does not occur. That fact allows us to conclude that the mixing of polyelectrolytes layers mixing at the stage of dissolution of CaCO3 core. The PMC with encapsulated protein has partial mixing of polyelectrolytes layers. That phenomenon may be due to the fact that seven-layered protein-containing microcapsules already have a dense and well-formed shell. The obtained data correlate with the data on the study of the surface charge of microcapsules.

Designing Functionalized Polyelectrolyte Microcapsules for Cancer Treatment

“…This could be accounted for by a higher permeability of the polyelectrolyte shell of the shell-type MCs because of a decreased charge density of PAH as a weak polyelectrolyte (with a pKa of about 8.5) [39]. Usually, when the core has been dissolved, the layers of the polyelectrolyte shell may be rearranged, which also alters the permeability of the polyelectrolyte structure, in contrast to core/shell MCs, where the shell, which is located on the core surface, is more stable [41]. However, the obtained data demonstrate that the small-sized MCs provide more extended DOX release compared to previously developed 5-µm alginate/chitosan MCs, which consist of 5 or 8 polyelectrolyte layers and are placed in an isotonic microenvironment or phosphate buffer saline (pH 7.4) [42,43].…”

Nanoarchitectonics beyond perfect order – not quite perfect but quite useful

“…, charge neutralization and re-saturation of the counterionic component materials upon adsorption onto the charged surface resulting in a charge reversal. 123–125 This permits alternate adsorption of cationic and anionic polyelectrolytes at a surface. 126 Besides, hydrogen-bonding interactions, 127–129 bio-specific interactions, 130 charge transfer interactions, 131 electrochemical reactions, 132 metal coordination, 133 stereo-complex formation, 134 sol/gel reactions, 135 molecular interactions, 136 or covalent bonding formation 137 can also act as driving forces of LbL assembly.…”

LbL Nano-Assemblies: A Versatile Tool for Biomedical and Healthcare Applications

“…Multilayered LbL thin films can be designed with controlled structures and properties, such as magnetic, optical, and biological [ 23 ]. Taking into account that LbL assembly is usually carried out at room temperature and in aqueous solution, it is appropriate to preserve the activity of proteins, nucleic acids, and other biomacromolecules.…”