title: "Smart" theranostic lanthanide nanoprobes with simultaneous up-conversion fluorescence and tunable T1-T2 magnetic resonance imaging contrast and near-infrared activated photodynamic therapy.
abstract: The current work reports a type of "smart" lanthanide-based theranostic nanoprobe, NaDyF4:Yb(3+)/NaGdF4:Yb(3+),Er(3+), which is able to circumvent the up-converting poisoning effect of Dy(3+) ions to give efficient near infrared (980 nm) triggered up-conversion fluorescence, and offers not only excellent dark T2-weighted MR contrast but also tunable bright and T1-weighted MR contrast properties. Due to the efficient up-converted energy transfer from the nanocrystals to chlorin e6 (Ce6) photosensitizers loaded onto the nanocrystals, cytotoxic singlet oxygen was generated and photodynamic therapy was demonstrated. Therefore, the current multifunctional nanocrystals could be potentially useful in various image-guided diagnoses where bright or dark MRI contrast could be selectively tuned to optimize image quality, but also as an efficient and more penetrative near-infrared activated photodynamic therapy agent.
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore 637459. tytan@ntu.edu.sg.
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Gautom Kumar
authors.initials: GK
authors.lastname: Das
authors.forename: Vimalan
authors.initials: V
authors.lastname: Vijayaragavan
authors.forename: Qing Chi
authors.initials: QC
authors.lastname: Xu
authors.forename: Parasuraman
authors.initials: P
authors.lastname: Padmanabhan
authors.forename: Kishore K
authors.initials: KK
authors.lastname: Bhakoo
authors.forename: Subramanian Tamil
authors.initials: ST
authors.lastname: Selvan
authors.forename: Timothy Thatt Yang
authors.initials: TT
authors.lastname: Tan
mesh_terms: D002470:Cell Survival; D002735:Chlorophyllides; D003287:Contrast Media / Q000737:chemistry; D005453:Fluorescence; D006367:HeLa Cells; D006801:Humans; D028581:Lanthanoid Series Elements / Q000737:chemistry*; D008279:Magnetic Resonance Imaging; D046529:Microscopy, Electron, Transmission; D008856:Microscopy, Fluorescence; D010100:Oxygen / Q000737:chemistry; D010778:Photochemotherapy; D017319:Photosensitizing Agents / Q000737:chemistry; D011092:Polyethylene Glycols / Q000737:chemistry; D011108:Polymers / Q000737:chemistry; D011166:Porphyrins / Q000737:chemistry; D017382:Reactive Oxygen Species / Q000737:chemistry; D026082:Singlet Oxygen / Q000737:chemistry; D013499:Surface Properties
chemical_list: D002735:Chlorophyllides; D003287:Contrast Media; D028581:Lanthanoid Series Elements; D017319:Photosensitizing Agents; D011108:Polymers; D011166:Porphyrins; D017382:Reactive Oxygen Species; D026082:Singlet Oxygen; D011092:Polyethylene Glycols; C062985:phytochlorin; D010100:Oxygen