title: Magnetofluorescent Carbon Dots Derived from Crab Shell for Targeted Dual-Modality Bioimaging and Drug Delivery.
abstract: We propose a one-pot microwave-assisted pyrolysis method for fabrication of magnetofluorescent carbon quantum dots (MFCQDs), using a combination of waste crab shell and three different transition-metal ions, Gd3+, Mn2+, and Eu3+, referred to as Gd@CQDs, Mn@CQDs, and Eu@CQDs, respectively. Chitin from waste crab shell acted not only as a carbon source but also as a chelating ligand to form complexes with transition-metal ions. Gd@CQDs exhibited a high r1relaxivity of 4.78 mM-1·s-1and a low r2/r1ratio of 1.33, suggesting that they show excellent potential as a T1contrast agent. Mn@CQDs and Eu@CQDs showed high r2relaxivity values of 140.7 and 28.32 mM-1·s-1, respectively, suggesting their potential for use as T2contrast agents. Further conjugation of Gd@CQDs with folic acid (FA) enabled specific targeting to folate receptor-positive HeLa cells, as confirmed via in vitro magnetic resonance and fluorescence imaging. Doxorubicin (DOX) was selected as a model drug for conjugation with FA-Gd@CQDs. The as-prepared nanocomposites showed significantly higher cytotoxicity toward HeLa cells than free DOX. No apparent cytotoxicity was observed in vivo (zebrafish embryos) or in vitro (cell viability), suggesting that MFCQDs show potential for development as diagnostic probes or theranostic agents.
authors.affiliation: Department of Chemical Engineering, National Taiwan University of Science and Technology , Taipei 10607, Taiwan, Republic of China.|Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan, Republic of China.
authors.forename: Yueh-Yun
authors.initials: YY
authors.lastname: Yao
authors.affiliation: Department of Chemical Engineering, National Taiwan University of Science and Technology , Taipei 10607, Taiwan, Republic of China.
authors.forename: Gangaraju
authors.initials: G
authors.lastname: Gedda
authors.affiliation: Department of Chemical Engineering, National Taiwan University of Science and Technology , Taipei 10607, Taiwan, Republic of China.
authors.forename: Wubshet Mekonnen
authors.identifier: http://orcid.org/0000-0003-3370-6731
authors.initials: WM
authors.lastname: Girma
authors.affiliation: Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan, Republic of China.
authors.forename: Chia-Liang
authors.initials: CL
authors.lastname: Yen
authors.affiliation: Department of Chemistry, National Tsing Hua University , Hsinchu 30013, Taiwan, Republic of China.
authors.forename: Yong-Chien
authors.initials: YC
authors.lastname: Ling
authors.affiliation: Department of Chemical Engineering, National Taiwan University of Science and Technology , Taipei 10607, Taiwan, Republic of China.
authors.forename: Jia-Yaw
authors.identifier: http://orcid.org/0000-0002-4172-6612
authors.initials: JY
authors.lastname: Chang
mesh_terms: D000818:Animals; D003386:Brachyura; D002244:Carbon; D016503:Drug Delivery Systems; D006367:HeLa Cells; D006801:Humans; D008279:Magnetic Resonance Imaging; D045663:Quantum Dots
chemical_list: D002244:Carbon
keywords: crab shell; drug carrier; fluorescence imaging; magnetic resonance imaging; magnetofluorescent