title: Bright far-red/near-infrared conjugated polymer nanoparticles for in vivo bioimaging.
abstract: A highly emissive far-red/near-infrared (FR/NIR) fluorescent conjugated polymer (CP), poly[(9,9-dihexylfluorene)-co-2,1,3-benzothiadiazole-co-4,7-di(thiophen-2-yl)-2,1,3-benzothiadiazole] (PFBTDBT10) is designed and synthesized via Suzuki polymerization. Formulation of PFBTDBT10 using 1,2-distearoyl-sn-glycero-3-phosphoethanolamine-N-[methoxy(polyethylene glycol)-2000] (DSPE-PEG2000 ) and DSPE-PEG5000-folate as the encapsulation matrix yielded CP-loaded DSPE-PEG-folic acid nanoparticles (CPDP-FA NPs) with bright FR/NIR fluorescence (27% quantum yield) and a large Stoke's shift of 233 nm in aqueous solution. CPDP-FA NPs show improved thermal/photostabilities and larger Stoke's shifts as compared to commercially available quantum dots (Qdot 655) and organic dyes such as Alexa Fluor 555 and Rhodamine 6G. In vivo studies of CPDP-FA NPs on a hepatoma H22 tumor-bearing mouse model reveal that they could serve as an efficient FR/NIR fluorescent probe for targeted in vivo fluorescence imaging and cancer detection in a high contrast and specific manner. Together with the negligible in vivo toxicity, CPDP-FA NPs are promising FR/NIR fluorescent probes for future in vivo applications.
authors.affiliation: Department of Chemical and Biomolecular Engineering, National University of Singapore, 117576, Singapore.
authors.forename: Dan
authors.initials: D
authors.lastname: Ding
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Guangxue
authors.initials: G
authors.lastname: Feng
authors.forename: Kai
authors.initials: K
authors.lastname: Li
authors.forename: Yong
authors.initials: Y
authors.lastname: Hu
authors.forename: Bin
authors.initials: B
authors.lastname: Liu
mesh_terms: D003952:Diagnostic Imaging / Q000379:methods*; D053758:Nanoparticles / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry*
chemical_list: D011108:Polymers
keywords: FR/NIR emission; conjugated polymers; fluorescent probes; in vivo fluorescence imaging; in vivo toxicity