title: Rapid cellular internalization of multifunctional star polymers prepared by atom transfer radical polymerization.
abstract: Poly(ethylene glycol) (PEG) star polymers containing GRGDS (Gly-Arg-Gly-Asp-Ser) peptide sequences on the star periphery were synthesized by atom transfer radical polymerization (ATRP) of poly(ethylene glycol) methyl ether methacrylate (PEGMA), GRGDS modified poly(ethylene glycol) acrylate (GRGDS-PEG-Acryl), fluorescein o-methacrylate (FMA), and ethylene glycol dimethacrylate (EGDMA) via an "arm-first" method. Star polymers were approximately 20 nm in diameter, as measured by dynamic light scattering and atomic force microscopy. Conjugation of FMA to the stars was confirmed by fluorescence microscopy, and successful attachment of GRGDS segments to the star periphery was confirmed by (1)H NMR spectroscopy. Both fluorescent PEG star polymers with and without peripheral GRGDS peptide segments were cultured with MC3T3-E1.4 cells. These star polymers were biocompatible with ≥ 90% cell viability after 24 h of incubation. Cellular uptake of PEG star polymers in MC3T3-E1.4 cells was observed by confocal microscopy. Rapid uptake of PEG star polymers with GRGDS peptides (∼ 100% of FITC-positive cells in 15 min measured by flow cytometry) was observed, suggesting enhanced delivery potential of these functional star polymers.
authors.affiliation: Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
authors.forename: Hong Y
authors.initials: HY
authors.lastname: Cho
authors.forename: Haifeng
authors.initials: H
authors.lastname: Gao
authors.forename: Abiraman
authors.initials: A
authors.lastname: Srinivasan
authors.forename: Joanna
authors.initials: J
authors.lastname: Hong
authors.forename: Sidi A
authors.initials: SA
authors.lastname: Bencherif
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Siegwart
authors.forename: Hyun-Jong
authors.initials: HJ
authors.lastname: Paik
authors.forename: Jeffrey O
authors.initials: JO
authors.lastname: Hollinger
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Matyjaszewski
mesh_terms: D000818:Animals; D001672:Biocompatible Materials / Q000138:chemical synthesis* / Q000737:chemistry* / Q000494:pharmacology; D001842:Bone and Bones / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D005434:Flow Cytometry; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D009842:Oligopeptides / Q000737:chemistry; D010006:Osteoblasts / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010446:Peptide Fragments / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000138:chemical synthesis* / Q000737:chemistry* / Q000494:pharmacology; D019904:Polymethyl Methacrylate / Q000737:chemistry
chemical_list: D001672:Biocompatible Materials; D009842:Oligopeptides; D010446:Peptide Fragments; D011108:Polymers; D011092:Polyethylene Glycols; D019904:Polymethyl Methacrylate; C049554:glycyl-arginyl-glycyl-aspartyl-serine