title: Closomers of high boron content: synthesis, characterization, and potential application as unimolecular nanoparticle delivery vehicles for boron neutron capture therapy.
abstract: Unique nanosized closomers of high boron content that may exhibit potential as boron neutron capture therapy target species have been synthesized. The design of these boron-rich nanospheres is based in part on previous work involving dodeca(carboranyl)-substituted closomers [Thomas, J.; Hawthorne, M. F. Chem. Commun. 2001, 1884-1885]. Coupling of ortho-carborane moieties through ester and ether linkages to the rigid [closo-B(12)(OH)(12)](2-) scaffold resulted in the development of a 12(12)-closomer-ester derivative, dodeca[6-(1,2-dicarba-closo-dodecaboran-1-yl)hexanoate]-closo-dodecaborate (2-), 6, and 12(12)-closomer-ether derivatives, dodeca[6-(2-methy1-1,2-dicarba-nido-dodecaboran-1-yl)hexyl]-closo-dodecaborane (14-), 14, and dodeca[6-(7,8-dicarba-nido-dodecaboran-7-yl)hexyl]-closo-dodecaborane (14-), 15. These closomers were investigated by UV-visible spectroscopy and cyclic voltammetry. Additionally, a deboronation method employing NaCN as the nucleophilic reagent was utilized to obtain sodium salts of the ether-linked nido-closomer polyanions, which were purified using a newly developed size-exclusion high pressure liquid chromatography method.
authors.affiliation: Department of Chemistry and Biochemistry, University of California-Los Angeles, 90095-1569, USA.
authors.forename: Ling
authors.initials: L
authors.lastname: Ma
authors.forename: Julie
authors.initials: J
authors.lastname: Hamdi
authors.forename: Francis
authors.initials: F
authors.lastname: Wong
authors.forename: M Frederick
authors.initials: MF
authors.lastname: Hawthorne
mesh_terms: D000818:Animals; D001895:Boron / Q000737:chemistry*; D001896:Boron Compounds / Q000138:chemical synthesis / Q000737:chemistry / Q000493:pharmacokinetics; D016754:Boron Neutron Capture Therapy; D002264:Carboxylic Acids / Q000737:chemistry; D016503:Drug Delivery Systems; D004986:Ether / Q000737:chemistry; D005260:Female; D046911:Macromolecular Substances / Q000138:chemical synthesis / Q000737:chemistry / Q000493:pharmacokinetics; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D015394:Molecular Structure; D049329:Nanostructures / Q000737:chemistry*; D014018:Tissue Distribution
chemical_list: D001896:Boron Compounds; D002264:Carboxylic Acids; D046911:Macromolecular Substances; D004986:Ether; D001895:Boron