RT Journal Article SR Electronic T1 Nanoparticles Modified by Encapsulation of Ligands with a Long Alkyl Chain to Affect Multispecific and Multimodal Imaging JF Journal of Nuclear Medicine JO J Nucl Med FD Society of Nuclear Medicine SP 1462 OP 1470 DO 10.2967/jnumed.111.092759 VO 53 IS 9 A1 Lee, Young Kyoung A1 Jeong, Jae Min A1 Hoigebazar, Lathika A1 Yang, Bo Yeun A1 Lee, Yun-Sang A1 Lee, Byung Chul A1 Youn, Hyewon A1 Lee, Dong Soo A1 Chung, June-Key A1 Lee, Myung Chul YR 2012 UL http://jnm.snmjournals.org/content/53/9/1462.abstract AB 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-C18, mannose-C18, lactose-C18, and 2-(p-isothiocyanatobenzyl)-1,4,7-triazacyclononane-1,4,7-triacetic acid-C18. And then we produced stable quantum dots (QDs) encapsulated with polysorbate 60 (a branched polyethylene glycol head with a C18 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 68Ga (a positron emitter) easily and with high efficiency. Conclusion: The nanoparticles encapsulated with special amphiphiles could provide a straightforward and novel imaging solution with multimodality and multispecificity.