Polyelectrolyte-coated nanoparticles or microparticles interact with bioactive molecules (peptides, proteins or nucleic acids) and have been proposed as delivery systems for these molecules. However, the mechanism of adsorption of polyelectrolyte onto particles remains unsolved. In this study, cationic poly(lactide-co-glycolide) (PLGA) nanoparticles were fabricated by adsorption of various conc...

Based on extensive Monte Carlo simulations and analytical considerations we study the electrostatically driven adsorption of flexible polyelectrolyte chains onto charged Janus nanospheres. These net-neutral colloids are composed of two equally but oppositely charged hemispheres. The critical binding conditions for polyelectrolyte chains are analysed as function of the radius of the Janus partic...

Using dissipative particle dynamics (DPD), we model the interfacial adsorption of pH-responsive polyelectrolytes and polyelectrolyte-grafted nanoparticles (PNPs) at a planar water-oil interface. The electrostatic interactions in the presence of the dielectric discontinuity across the interface are modeled by exploiting the Groot method, which uses an iterative method to solve the Poisson equati...

The present study demonstrates that multivalent counterions trigger adsorption of polyelectrolytes on a like-charged substrate. In particular, adsorption of polystyrene sulfonate on silica is studied experimentally in NaCl, MgCl2, and LaCl3 solutions by optical reflectivity. While adsorption is negligible in the presence of Na(+), the polyelectrolyte adsorbs in the presence of Mg(2+) and La(3+)...

Layer-by-layer self-assembled polyelectrolyte shells are a new class of micro/nanocapsules with unique physicochemical properties for potential applications in drug/gene delivery. The objective of this study was to investigate the interactions of polyelectrolyte shells ( approximately 1 mum in diameter) with MCF-7 breast cancer cells and identify key parameters that affect such interactions. Ta...

In this investigation surface force, X-ray photoelectron spectroscopy and ellipsometry techniques have been used to study the adsorption of a low-charge-density cationic polyelectrolyte on negatively charged surfaces. It is shown that the low cationicity of this polyelectrolyte induces an adsorption behavior which is limited by steric factors rather than by the substrate surface charge or poten...

Polyelectrolyte surface-modified cowpea mosaic virus (CPMV) can be used for the templated synthesis of narrowly dispersed gold nanoparticles. Cationic polyelectrolyte, poly(allylamine) hydrochloride, is electrostatically bound to the external surface of the virus capsid. The polyelectrolyte-coated CPMV promotes adsorption of aqueous gold hydroxide anionic species, prepared from gold(III) chlori...

We consider the adsorption of bovine serum albumin (BSA) on spherical polyelectrolyte brushes (SPB). The SPB consist of asolid polystyrene core of 100 nm diameter onto which linear polyelectrolyte chains [poly(acrylic acid), (PAA)] are grafted. The adsorption of BSA is studied at a pH of 6.1 at different concentrations of added salt and buffer. We observe strong adsorption of BSA onto the SPB d...

The formation of complexes between nanoparticles and polyelectrolytes is a key process for the control of the reactivity of manufactured nanoparticles and rational design of core shell nanostructures. In this work, we investigate the influence of the nanoparticle dielectric constant on the adsorption of a linear charged polymer (polyelectrolyte) at the surface of a neutral nanoparticle. The pol...

Complex formation between a weak flexible polyelectrolyte chain and one positively charged nanoparticle in presence of explicit counterions and salt particles is investigated using Monte Carlo simulations. The influence of parameters such as the nanoparticle surface charge density, salt valency, and solution property such as the pH on the chain protonation/deprotonation process and monomer adso...