Transfection by polyethyleneimine-coated microspheres

W. S. Manuel, J. Zheng, P. J. Hornsby

Research output: Contribution to journalArticlepeer-review

26 Scopus citations


Polyethyleneimine (PEI) can be used as a DNA delivery mechanism in cell culture and in vivo. Cells can be transfected by using surface-bound PEI, as well as by PEI/DNA microparticles. In the present experiments we extended these observations by preparing microspheres with covalently attached PEI. Blends of poly(ε-CBZ-L-lysine) mixed with poly(D,L-lactic-co-glycolic acid) were formed into microspheres using a double-emulsification/solvent evaporation procedure. CBZ (carbobenzoxy) groups on the surface of microspheres were removed by Li0/liquid ammonia reduction. Surface amino groups were used for covalent attachment of PEI and other molecules. Silica microspheres with bonded-phase PEI were also used. Microspheres were mixed with plasmid DNA encoding green fluorescent protein and added to cultured cells. PEI-coated microspheres transfected cultured Caco cells and MH-S alveolar macrophages. Expression of the transfected DNA increased over several days. MH-S cells phagocytosed PEI-coated silica microspheres, which were shown to reside in an acidic subcellular compartment. This was demonstrated by conjugating a pH-sensitive fluorescent dye (seminaphthofluorescein, SNAFL) to the microsphere surface. Transfection of MH-S cells was increased when plasmid DNA was complexed with histone on the surface of the microspheres. Conclusions PEI-coated microspheres have potential as a DNA delivery device with advantages of the unique properties of PEI and ease of surface chemical modification.

Original languageEnglish (US)
Pages (from-to)15-22
Number of pages8
JournalJournal of Drug Targeting
Issue number1
StatePublished - 2001
Externally publishedYes


  • Microspheres
  • Polyethyleneimine
  • Polymers
  • Transfection

ASJC Scopus subject areas

  • Pharmaceutical Science


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