Stepwise polyelectrolyte assembly on particle surfaces: a novel approach to colloid design

Abstract

Polyelectrolyte multilayers were deposited onto polystyrene and melamine formaldehyde latex particles by means of consecutive adsorption. Two different methods of multilayer growth were employed. First, adsorption of polyelectrolytes at a concentration exceeding saturation amounts was combined with the removal of the nonbound polyelectrolyte by means of centrifugation. Second, adsorption of polyelectrolyte was performed at a concentration just sufficient for saturation coverage. Both methods yielded continuous layer growth. The process of film formation was followed by electrophoresis, dynamic light scattering, single particle light scattering and fluorescence intensity measurements. Layer deposition onto partially crosslinked melamine resin latex particles, which were soluble at pH values of less than 1.6, resulted in the production of three‐dimensional thin polyelectrolyte shells upon dissolving the core. The ultrathin shells were observed by means of scanning and transmission electron microscopy. © 1998 John Wiley & Sons, Ltd.

Fluorescent Dyes Used in Polymer Carriers as Imaging Agents in Anticancer Therapy

“…For instance, decomposable hollow capsules were obtained by adsorption of sperimidine (which is a low molecular weight organic polyamine) alternately with DNA on colloids (MnCO 3 particles). The multilayers DNA/spermidine formed the shell of capsules then a templated core was removed with acid [331][332][333][334][335]. DNA is negatively charged due to the phosphate group in its backbone, while a sperimidine in its ionized form contains three positive charges.…”

“…Such capsules may be exploited for the release of many other encapsulated compounds such as dyes or drugs. So, selecting a composition of the capsules wall by using e.g., rhodaminelabeled DNA [332] can provide tailored delivery vehicles with a specific targeting capability. Moreover, the anionic dye pyrene chromophore (i.e., pyrenetetrasulfonic acid) (4-PSA) which exhibits four negative charges forms a complex with cationic polyelectrolyte chains with a very high binding constant [340].…”

Polymeric multilayer capsules delivering biotherapeutics

“…(B) Scanning electron microscopy images of (B1) bare CaCO 3 templates and (B2) BSA loaded CaCO 3 through co-precipitation. (C) Scanning electron microscopy images of (C1) empty and (C2) BSA loaded (PAH/PSS) 5 capsules.…”

“…[2,3] Polymeric multilayer capsules are fabricated through step-wise adsorption of polymers using electrostatics, H-bonding, covalent chemistry, etc… as driving force, followed by the dissolution of the core template. [4,5] One of their most striking properties is their permselectivity in aqueous medium. [6] While the polymeric shell is fully permeable to low molecular weight compounds such as ions and small drug molecules, they are impermeable to larger molecules.…”

Azobenzene Polymers for Photonic Applications

“…Colloids have been efficiently coated with PEMs (Caruso, 2001;Sukhorukov et al, 1998b), and by dissolving the core one can also form hollow PEM microcapsules (Sukhorukov et al, 1998a). Multilayers can be formed on nearly any material (glass, quartz, silicon, most metals, etc.)…”