title: Nanoparticles modified by encapsulation of ligands with a long alkyl chain to affect multispecific and multimodal imaging.
abstract: The attachment of specific ligands to the surfaces of nanoparticles is important for medical and biologic imaging. However, covalent modification of nanoparticles has inherent problems in reproducibility because of many factors such as temperature, pH, concentration, and reaction time. Thus, we developed a method for modifying nanoparticles by encapsulation with specific ligand-conjugated amphiphiles.
  
  
  METHODS
  We synthesized special amphiphiles with a hydrophilic head and a long single-alkyl chain, such as arginine-glycine-aspartic acid-C(18), mannose-C(18), lactose-C(18), and 2-(p-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid-C(18). And then we produced stable quantum dots (QDs) encapsulated with polysorbate 60 (a branched polyethylene glycol head with a C(18) tail) and the synthesized special amphiphiles. The prepared encapsulated QDs were subject to in vitro and in vivo animal biodistribution studies and small-animal PET studies to confirm their specific binding.
  
  
  RESULTS
  The encapsulated QDs could specifically bind to target cells in vitro and in vivo and could be labeled with (68)Ga (a positron emitter) easily and with high efficiency.
  
  
  CONCLUSIONS
  The nanoparticles encapsulated with special amphiphiles could provide a straightforward and novel imaging solution with multimodality and multispecificity.
authors.affiliation: Department of Nuclear Medicine, Institute of Radiation Medicine, Seoul National University College of Medicine, Seoul, South Korea.
authors.forename: Young Kyoung
authors.initials: YK
authors.lastname: Lee
authors.forename: Jae Min
authors.initials: JM
authors.lastname: Jeong
authors.forename: Lathika
authors.initials: L
authors.lastname: Hoigebazar
authors.forename: Bo Yeun
authors.initials: BY
authors.lastname: Yang
authors.forename: Yun-Sang
authors.initials: YS
authors.lastname: Lee
authors.forename: Byung Chul
authors.initials: BC
authors.lastname: Lee
authors.forename: Hyewon
authors.initials: H
authors.lastname: Youn
authors.forename: Dong Soo
authors.initials: DS
authors.lastname: Lee
authors.forename: June-Key
authors.initials: JK
authors.lastname: Chung
authors.forename: Myung Chul
authors.initials: MC
authors.lastname: Lee
mesh_terms: D000818:Animals; D002214:Capsules; D045744:Cell Line, Tumor; D005260:Female; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D007785:Lactose / Q000737:chemistry; D008024:Ligands; D008099:Liver / Q000098:blood supply / Q000000981:diagnostic imaging / Q000378:metabolism; D008358:Mannose / Q000737:chemistry; D051379:Mice; D057054:Molecular Imaging / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry*; D009389:Neovascularization, Pathologic / Q000000981:diagnostic imaging / Q000378:metabolism; D009842:Oligopeptides / Q000737:chemistry; D011136:Polysorbates / Q000737:chemistry; D045663:Quantum Dots; D011877:Radionuclide Imaging; D013154:Spleen / Q000098:blood supply / Q000000981:diagnostic imaging / Q000378:metabolism
chemical_list: D002214:Capsules; D008024:Ligands; D009842:Oligopeptides; D011136:Polysorbates; C047981:arginyl-glycyl-aspartic acid; D007785:Lactose; D008358:Mannose