title: Transepithelial transport of PEGylated anionic poly(amidoamine) dendrimers: implications for oral drug delivery.
abstract: The purpose of this work was to assess the impact of PEGylation on transepithelial transport of anionic poly(amidoamine) dendrimers. Cytotoxicity, uptake and transport across Caco-2 cells of PEGylated G3.5 and G4.5 PAMAM dendrimers were studied. Methoxy polyethylene glycol (750 Da) was conjugated to carboxylic acid-terminated PAMAM dendrimers at feed ratios of 1, 2 and 4 PEG per dendrimer. Compared to the control, PEGylation of anionic dendrimers did not significantly alter cytotoxicity up to a concentration of 0.1 mM. PEGylation of G3.5 dendrimers significantly decreased cellular uptake and transepithelial transport while PEGylation of G4.5 dendrimers led to a significant increase in uptake, but also a significant decrease in transport. Dendrimer PEGylation reduced the opening of tight junctions as evidenced by confocal microscopy techniques. Modulation of the tight junctional complex correlated well with changes in PEGylated dendrimer transport and suggests that anionic dendrimers are transported primarily through the paracellular route. PEGylated dendrimers show promise in oral delivery applications where increased functionality for drug conjugation and release is desired.
authors.affiliation: Fischell Department of Bioengineering, University of Maryland, College Park, MD 20742, USA.
authors.forename: Deborah M
authors.initials: DM
authors.lastname: Sweet
authors.forename: Rohit B
authors.initials: RB
authors.lastname: Kolhatkar
authors.forename: Abhijit
authors.initials: A
authors.lastname: Ray
authors.forename: Peter
authors.initials: P
authors.lastname: Swaan
authors.forename: Hamidreza
authors.initials: H
authors.lastname: Ghandehari
mesh_terms: D000284:Administration, Oral; D018938:Caco-2 Cells; D002463:Cell Membrane Permeability; D002470:Cell Survival / Q000187:drug effects; D050091:Dendrimers; D006801:Humans; D008565:Membrane Proteins / Q000032:analysis / Q000378:metabolism; D062793:Occludin; D011073:Polyamines / Q000138:chemical synthesis / Q000737:chemistry* / Q000493:pharmacokinetics*; D011092:Polyethylene Glycols / Q000737:chemistry*; D019108:Tight Junctions / Q000378:metabolism
chemical_list: D050091:Dendrimers; D008565:Membrane Proteins; C568985:OCLN protein, human; D062793:Occludin; C104700:PAMAM Starburst; D011073:Polyamines; D011092:Polyethylene Glycols