Stable stealth function for hollow polyelectrolyte microcapsules through a poly(ethylene glycol) grafted polyelectrolyte adlayer

Biomacromolecules. 2008 Jan;9(1):100-8. doi: 10.1021/bm700857s. Epub 2007 Dec 14.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Survival
  • Cells, Cultured
  • Dendritic Cells / chemistry
  • Dendritic Cells / immunology
  • Drug Carriers
  • Electrolytes / chemistry*
  • Humans
  • Macrophages / chemistry
  • Macrophages / immunology
  • Microscopy, Confocal
  • Microspheres
  • Phagocytosis
  • Polyethylene Glycols / chemistry*


  • Drug Carriers
  • Electrolytes
  • Polyethylene Glycols