title: Novel pH-responsive polymeric micelles prepared through self-assembly of amphiphilic block copolymer with poly-4-vinylpyridine block synthesized by mechanochemical solid-state polymerization.
abstract: We fabricated polymeric micelles containing 5-fluorouracil (5-FU) or fluorescein using the amphiphilic block copolymer, poly-4-vinylpyridine-b-6-O-methacryloyl galactopyranose. Although the polymeric micelles were stable at pH 7.4, they readily decomposed at pH 5, resulting in near complete release of 5-FU. Uptake of polymeric micelles containing fluorescein by HepG2 and HCT116 cells was also investigated. With both cell types, strong fluorescence was observed after a 12-h incubation, but the fluorescence weakened after 24 h of incubation. The fluorescein incorporated into the polymeric micelles was released into acidic organelles (endosome and/or lysosome), from which it diffused throughout the cell. The cytotoxicity of polymeric micelles containing 5-FU was evaluated against HepG2 cells using a CCK-8 assay. The results suggest that polymeric micelles containing 5-FU are more cytotoxic to HepG2 cells than free 5-FU.
authors.affiliation: Laboratory of Pharmaceutical Physical Chemistry, Gifu Pharmaceutical University.
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Kondo
authors.forename: Yuna
authors.initials: Y
authors.lastname: Asano
authors.forename: Natsumi
authors.initials: N
authors.lastname: Koizumi
authors.forename: Kenjiro
authors.initials: K
authors.lastname: Tatematsu
authors.forename: Yuka
authors.initials: Y
authors.lastname: Sawama
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Sasai
authors.forename: Yukinori
authors.initials: Y
authors.lastname: Yamauchi
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kuzuya
authors.forename: Shigeru
authors.initials: S
authors.lastname: Kurosawa
mesh_terms: D002470:Cell Survival / Q000187:drug effects; D004337:Drug Carriers / Q000737:chemistry; D000067493:Dynamic Light Scattering; D005472:Fluorouracil / Q000737:chemistry* / Q000633:toxicity; D045325:HCT116 Cells; D056945:Hep G2 Cells; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008823:Micelles; D018613:Microscopy, Confocal; D011108:Polymers / Q000737:chemistry*
chemical_list: D004337:Drug Carriers; D008823:Micelles; D011108:Polymers; D005472:Fluorouracil