当前位置： SCI文献检索 > INVESTIGATIVE RADIOLOGY期刊下所有文献 > Fluorescent bacterial magnetic nanoparticles as bimodal contrast agents.

Fluorescent bacterial magnetic nanoparticles as bimodal contrast agents.

Abstract：

OBJECTIVES:The purpose of this study was to assess whether fluorochrome-coupled bacterial magnetic nanoparticles can be used as bimodal contrast agent for both magnetic resonance imaging (MRI) and near-infrared fluorescence optical (NIRF) imaging of cultured macrophages. MATERIALS AND METHODS:Bacterial magnetic nanoparticles (magnetosomes, particle diameter: 42 nm) were harvested from Magnetospirillum gryphiswaldense and characterized by using MRI. After covalent coupling to the fluorescent dye DY-676 (lambdaabs./lambdaem.= 676 nm/701 nm, Dyomics, Jena, Germany), the fluorescent magnetosomes were analyzed by fluorescence-activated cell sorting. Subsequently, murine macrophages J774 were incubated with the bimodal contrast agent (3 hours) and examined by a whole-body near infrared small animal imaging system as well as by using a 1.5 T clinical MR system. Moreover, labeled cells were characterized using confocal laser scanning microscopy (CLSM) and ultrathin section transmission electron microscopy. RESULTS:Characterization of the nanoparticles by MRI revealed R1 and R2 relaxivities of 3.2 mMs and 526 mMs, respectively. Fluorochrome-coupled magnetosomes exhibited increased fluorescence intensities at wavelengths >670 nm. Macrophages that were incubated with the contrast agent showed a significant fluorescence emission in the near infrared range as imaged with a whole body NIR imaging system, FACS analysis and CLSM. Moreover, CLSM data showed the greatest fluorescence intensities within intracellular compartments and colocalized with the magnetosomes. With MRI, both T1 and T2 relaxation times were substantially shortened at concentrations greater than 600 cells/microL. DISCUSSION AND CONCLUSION:Macrophages could be labeled with fluorescent magnetosomes, and they were successfully imaged using both a 1.5 T MR scanner as well as with NIRF optical methods. The use of this bimodal contrast agent for diagnostic purposes may benefit from the excellent spatial resolution of the MRI and the high sensitivity of the fluorescence imaging.

journal_name

Invest Radiol

journal_title

Investigative radiology

authors

Lisy MR,Hartung A,Lang C,Schüler D,Richter W,Reichenbach JR,Kaiser WA,Hilger I

doi

10.1097/01.rli.0000255832.44443.e7

subject

Has Abstract

pub_date

2007-04-01 00:00:00

pages

235-41

issue

eissn

0020-9996

issn

1536-0210

pii

00004424-200704000-00006

journal_volume

pub_type

杂志文章

在线工具

Fluorescent bacterial magnetic nanoparticles as bimodal contrast agents.