title: PEGylation of hyaluronic acid nanoparticles improves tumor targetability in vivo.
abstract: A major drawback of hyaluronic acid (HA)-based drug conjugates or nanoparticles for cancer therapy is their preferential accumulation in the liver after systemic administration. In an attempt to investigate the physicochemical characteristics and in vivo fates of poly(ethylene glycol) (PEG)-conjugated HA nanoparticles (HA-NPs), amphiphilic HA derivatives were prepared by varying the degree of PEGylation. The PEGylated HA-NPs formed self-assembled nanoparticles (217-269 nm in diameter) with the negatively charged surfaces in the physiological condition. Although PEGylation of HA-NPs reduced their cellular uptake in vitro, larger amounts of nanoparticles were taken up by cancer cells over-expressing CD44, an HA receptor, than by normal fibroblast cells. The ex vivo images of the organs using an optical imaging technique after the intravenous injection of Cy5.5-labeled nanoparticles into normal mice demonstrated that PEGylation could effectively reduce the liver uptake of HA-NPs and increase their circulation time in the blood. When the nanoparticles were systemically administered into tumor-bearing mice for in vivo real-time imaging, the strongest fluorescence signals were detected at the tumor site of the mice for the whole period of time studied, indicating their high tumor targetability. Interestingly, PEGylated HA-NPs were more effectively accumulated into the tumor tissue up to 1.6-fold higher than bare HA-NPs. The high tumor targetability of PEGylated HA-NPs was further supported by the intravital tumor imaging, in which their rapid extravasation into the tumor tissue was clearly observed. These results suggest that PEGylated HA-NPs can be useful as a means for cancer therapy and diagnosis.
authors.affiliation: Department of Life and Nanopharmaceutical Sciences, Kyung Hee University, Seoul 130-701, Republic of Korea.
authors.forename: Ki Young
authors.initials: KY
authors.lastname: Choi
authors.forename: Kyung Hyun
authors.initials: KH
authors.lastname: Min
authors.forename: Hong Yeol
authors.initials: HY
authors.lastname: Yoon
authors.forename: Kwangmeyung
authors.initials: K
authors.lastname: Kim
authors.forename: Jae Hyung
authors.initials: JH
authors.lastname: Park
authors.forename: Ick Chan
authors.initials: IC
authors.lastname: Kwon
authors.forename: Kuiwon
authors.initials: K
authors.lastname: Choi
authors.forename: Seo Young
authors.initials: SY
authors.lastname: Jeong
mesh_terms: D000818:Animals; D002460:Cell Line; D002522:Chlorocebus aethiops; D045325:HCT116 Cells; D006801:Humans; D006820:Hyaluronic Acid / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D008819:Mice, Nude; D053758:Nanoparticles / Q000737:chemistry* / Q000627:therapeutic use; D009369:Neoplasms / Q000188:drug therapy*; D011092:Polyethylene Glycols / Q000737:chemistry*
chemical_list: D011092:Polyethylene Glycols; D006820:Hyaluronic Acid