title: Quantum dots based molecular beacons for in vitro and in vivo detection of MMP-2 on tumor.
abstract: Matrix metalloproteinase-2 (MMP-2) is a protease related to tumor invasion and metastasis. It is heavily secreted by malignant tumor cells, allowing the protease to serve as an imaging biomarker of cancer. In this study, a novel sensing system based on fluorescence resonance energy transfer (FRET) from quantum dot (QD, the donor) to organic dye (the acceptor) was constructed for the in vitro and in vivo detection of matrix metalloproteinases-2 via a MMP-2-specific peptide substrate (GPLGVRGKGG). Specifically, 535 nm-emitting CdTe QD were bound to Rhodamine B (RB) through the peptide for in vitro detection of MMP-2, while 720 nm-emitting CdTeS QDs was linked to near infrared dye ICG-Der-02 (MPA) by the peptide for measurement in vivo. When these probes were exposed to MMP-2, the selective cleavage of the peptide resulted in the recovery of fluorescence from QDs. By using the produced 540QD-peptide-RB and 720QD-peptide-MPA probes, we successfully examined MMP-2 in live cells and tumor on nude mouse, respectively. Due to the tunable fluorescence of Qds, this nanosensor can be fine-tuned for a wide range of applications such as the detection of different biomarkers and early diagnosis of disease.
authors.affiliation: Department of Biomedical Engineering, China Pharmaceutical University, Nanjing 210009, China; School of Pharmacy, Xinjiang Medical University, Urumqi, Xinjiang 830011, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.affiliation: Department of Biomedical Engineering, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Dawei
authors.initials: D
authors.lastname: Deng
authors.affiliation: Department of Biomedical Engineering, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Jianpeng
authors.initials: J
authors.lastname: Xue
authors.affiliation: Department of Biomedical Engineering, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Lingzhi
authors.initials: L
authors.lastname: Qu
authors.affiliation: Department of Radiology, School of Medicine, Washington University, St. Louis, MO 63110, USA.
authors.forename: Samuel
authors.initials: S
authors.lastname: Achilefu
authors.affiliation: Department of Biomedical Engineering, China Pharmaceutical University, Nanjing 210009, China. Electronic address: guyueqingsubmission@hotmail.com.
authors.forename: Yueqing
authors.initials: Y
authors.lastname: Gu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015374:Biosensing Techniques / Q000379:methods; D045744:Cell Line, Tumor; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D005456:Fluorescent Dyes / Q000737:chemistry*; D006801:Humans; D020778:Matrix Metalloproteinase 2 / Q000032:analysis* / Q000378:metabolism; D051379:Mice; D009369:Neoplasms / Q000175:diagnosis / Q000201:enzymology*; D061848:Optical Imaging / Q000379:methods; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D045663:Quantum Dots / Q000737:chemistry*; D012235:Rhodamines / Q000737:chemistry*
chemical_list: D005456:Fluorescent Dyes; D010455:Peptides; D012235:Rhodamines; D020778:Matrix Metalloproteinase 2; C029773:rhodamine B
keywords: FRET; Matrix metalloproteinase-2; Near infrared imaging; Proteolytic activity; Quantum dots