title: In vivo tumor targeting and radionuclide imaging with self-assembled nanoparticles: mechanisms, key factors, and their implications.
abstract: The development of more selective delivery systems for cancer diagnosis and chemotherapy is one of the most important goals of current anticancer research. The purpose of this study is to evaluate various self-assembled nanoparticles as candidates to shuttle radionuclide and/or drugs into tumors and to investigate the mechanisms underlying the tumor targeting with self-assembled nanoparticles. By combining different hydrophobic moieties and hydrophilic polymer backbones, various self-assembled nanoparticles were prepared, and their in vivo distributions in tumor-bearing mice were studied by radionuclide imaging. One type of nanoparticles (fluorescein isothiocyanate-conjugated glycol chitosan (FGC) nanoparticles) exhibited highly selective tumoral localization. Scintigraphic images obtained 1 day after the intravenous injection of FGC nanoparticles clearly delineated the tumor against adjacent tissues. The mechanisms underlying the tumor targeting with self-assembled nanoparticles were investigated in terms of the physicochemical properties of nanoparticles and tumor microenvironments. FGC nanoparticles were preferentially localized in perivascular regions, implying their extravasation to tumors through the hyperpermeable tumor vasculature. The magnitude and pattern of tumoral distribution of self-assembled nanoparticles were influenced by several key factors--(i) in vivo colloidal stability: nanoparticles should maintain their intact nanostructures in vivo for a long period of time, (ii) particle size, (iii) intracellular uptake of nanoparticle: fast cellular uptake greatly facilitates the tumor targeting, (iv) tumor angiogenesis: pathological angiogenesis permits access of nanoparticles to tumors. We believe that this work can provide insight for the engineering of nanoparticles and be extended to cancer therapy and diagnosis, so as to deliver multiple therapeutic agents and imaging probes at high local concentrations.
authors.affiliation: Department of Chemical Engineering, Hanyang University, Ansan 426 791, Republic of Korea.
authors.forename: Yong Woo
authors.initials: YW
authors.lastname: Cho
authors.forename: Soo Ah
authors.initials: SA
authors.lastname: Park
authors.forename: Tae Hee
authors.initials: TH
authors.lastname: Han
authors.forename: Dai Hyun
authors.initials: DH
authors.lastname: Son
authors.forename: Ji Sun
authors.initials: JS
authors.lastname: Park
authors.forename: Seung Jun
authors.initials: SJ
authors.lastname: Oh
authors.forename: Dae Hyuk
authors.initials: DH
authors.lastname: Moon
authors.forename: Kyung-Ja
authors.initials: KJ
authors.lastname: Cho
authors.forename: Cheol-Hee
authors.initials: CH
authors.lastname: Ahn
authors.forename: Youngro
authors.initials: Y
authors.lastname: Byun
authors.forename: In-San
authors.initials: IS
authors.lastname: Kim
authors.forename: Ick Chan
authors.initials: IC
authors.lastname: Kwon
authors.forename: Sang Yoon
authors.initials: SY
authors.lastname: Kim
mesh_terms: D000818:Animals; D003460:Crystallization / Q000379:methods; D004337:Drug Carriers / Q000008:administration & dosage* / Q000737:chemistry / Q000493:pharmacokinetics*; D016503:Drug Delivery Systems / Q000379:methods*; D008657:Metabolic Clearance Rate; D051379:Mice; D008807:Mice, Inbred BALB C; D053758:Nanoparticles / Q000008:administration & dosage* / Q000737:chemistry*; D009369:Neoplasms / Q000000981:diagnostic imaging* / Q000378:metabolism*; D009928:Organ Specificity; D010316:Particle Size; D011877:Radionuclide Imaging; D014018:Tissue Distribution
chemical_list: D004337:Drug Carriers