title: Stable stealth function for hollow polyelectrolyte microcapsules through a poly(ethylene glycol) grafted polyelectrolyte adlayer.
abstract: Prospective biomedical applications of hollow polyelectrolyte microcapsules, for example, as drug delivery systems, require surface modifications that help to escape clearance by the mononuclear phagocytic system (MPS). Layer-by-layer assembled microcapsules that were alternatingly composed of polystyrene sulfonate (PSS) and polyallylamine hydrochloride (PAH) were coated with adlayers of poly(ethylene glycol) (PEG)-grafted poly-L-lysine (PLL-g-PEG) and poly-L-glutamic acid (PGA-g-PEG). Their effects on MPS recognition were studied in primary cell cultures of human monocyte derived dendritic cells and macrophages. PGA-g-PEG coatings had no significant effect on cellular recognition, which may be explained by insufficient PEG density of the adlayer. Contrary, PLL-g-PEG effectively blocked phagocytosis of coated microcapsules. In addition, PLL-g-PEG coatings showed efficient adlayer stability for at least 3 weeks, and PAH/PSS microcapsules did not impair phagocyte viability. Our results demonstrate that layer-by-layer assembled polyelectrolyte microcapsules coated with a PEG-grafted polyelectrolyte, PLL-g-PEG, represent a promising platform for a drug delivery system that escapes fast clearance by the MPS.
authors: Institute for Pharmaceutical Sciences, ETH Zurich, 8093 Zurich, Switzerland, Max-Planck Institute of Colloids and Interfaces, Research Campus Golm, 14424 Potsdam, Germany.
authors: Uta
authors: U
authors: Wattendorf
authors: Oliver
authors: O
authors: Kreft
authors: Marcus
authors: M
authors: Textor
authors: Gleb B
authors: GB
authors: Sukhorukov
authors: Hans P
authors: HP
authors: Merkle
mesh_terms: D002470:Cell Survival; D002478:Cells, Cultured; D003713:Dendritic Cells / Q000737:chemistry / Q000276:immunology; D004337:Drug Carriers; D004573:Electrolytes / Q000737:chemistry*; D006801:Humans; D008264:Macrophages / Q000737:chemistry / Q000276:immunology; D018613:Microscopy, Confocal; D008863:Microspheres; D010587:Phagocytosis; D011092:Polyethylene Glycols / Q000737:chemistry*
chemical_list: D004337:Drug Carriers; D004573:Electrolytes; D011092:Polyethylene Glycols