1 research outputs found
Detecting Chronic Post-Traumatic Osteomyelitis of Mouse Tibia via an IL-13Rα2 Targeted Metallofullerene Magnetic Resonance Imaging Probe
Differential diagnosis
of chronic post-traumatic osteomyelitis
(CPO) from aseptic inflammation remains challenging, since both pathological
processes share similar clinical symptoms. Here we utilized a novel
targeted metallofullerene nanoparticle based magnetic resonance imaging
(MRI) probe IL-13-TAMRA-Gd<sub>3</sub>N@C<sub>80</sub>(OH)<sub>30</sub>(CH<sub>2</sub>CH<sub>2</sub>COOH)<sub>20</sub> to detect CPO in mouse tibia via overexpressed IL-13Rα2 receptors.
The functionalized metallofullerene was characterized by X-ray photoelectron
spectroscopy. Upon lipopolysaccharide (LPS) stimulation, macrophage
Raw 264.7 cells showed elevated IL-13Rα2 expression via immunofluorescence
staining and increased MRI probe binding via built-in TAMRA fluorescence
imaging. Trauma was induced in both tibia of mice and bacteria soaked
suture was inserted into the right tibia to initiate infection. During
the acute phase (1.5 weeks), luminol-bioluminescence imaging revealed
much higher myeloperoxidase activity in the infected tibia compared
to the sham. In the chronic phase (4 weeks), X-ray radiography illustrated
bone deformation in the infected tibia compared to the sham. With <i>T</i><sub>1</sub> weighted sequences, the probe clearly exhibited
hyperintensity in the infection foci at both acute and chronic phases,
which was not observed in the sham tibia. Histological analysis revealed
severe bone structural destruction and massive inflammatory cell infiltration
in the infected tibia. Immunohistochemistry confirmed abundant expression
of IL-13Rα2 in the infection site. In summary, we developed
a noninvasive imaging approach to detect and differentiate CPO from
aseptic inflammation using a new IL-13Rα2 targeted metallofullerene
MRI probe. In addition, for the first time, IL-13Rα2 was investigated
as a unique biomarker in the context of osteomyelitis. Our data established
a foundation for the translational application of this MRI probe in
the clinical differentiation of CPO