The Board of Trustees of the Leland Stanford Junior University
发明人:
Sanjiv S. Gambhir,Michael Benoit,A. C. Matin,Yoram Barak,Shay Keren,Dirk Mayer
申请号：
US13845923
公开号：
US20130224122A1
申请日:
2013.03.18
申请国别(地区):
US
年份:
2013
代理人:
摘要：
Magnetic resonance imaging (MRI) is enhanced by contrast agents such as superparamagnetic iron-oxide (SPIO) particles that resemble magnetite particles produced by magnetotactic bacteria. Magnetospirillum magneticum AMB-1 produces positive MRI contrast when generating ultrasmall magnetite particles (10-40 nm diameter). Positive MRI contrast permits clearer distinction from image voids compared to negative contrast. T1-weighted MRI showed that such bacteria increased positive contrast 2.2-fold (p<0.02) in vitro and 2.0-fold (p<0.02) following intratumoral injection in mouse tumor xenografts. Upon intravenous delivery, Magnetospirillum magneticum AMB-1 targeted tumors and generated increased positive MRI contrast in them (1.4-fold p<0.01). AMB-1 tumor targeting was shown by viable counts, microPET imaging of radio-labeled AMB-1, and Prussian blue staining of tumor sections. Thus, magnetotactic bacteria provide a tool for improving cancer diagnosis and monitoring treatment response by MRI.
