Stable Confinement of Positron Emission Tomography and Magnetic Resonance Agents Within Carbon Nanotubes for Bimodal Imaging

Abstract

Aims: Simultaneous positron emission tomography/MRI has recently been introduced to the clinic and dual positron emission tomography/MRI probes are rare and of growing interest. We have developed a strategy for producing multimodal probes based on a carbon nanotube platform without the use of chelating ligands. Materials & methods: Gd³⁺ and ⁶⁴Cu²⁺ ions were loaded into ultra-short single-walled carbon nanotubes by sonication. Normal, tumor-free athymic nude mice were injected intravenously with the probe and imaged over 48 h. Results & conclusion: The probe was stable for up to 24 h when challenged with phosphate-buffered saline and mouse serum. Positron emission tomography imaging also confirmed the stability of the probe in vivo for up to 48 h. The probe was quickly cleared from circulation, with enhanced accumulation in the lungs. Stable encapsulation of contrast agents within ultra-short single-walled carbon nanotubes represents a new strategy for the design of advanced imaging probes with variable multimodal imaging capabilities.

Keywords::

• carbon nanotube
• contrast agent
• MRI
• multimodal imaging
• positron emission tomography

Financial & competing interests disclosure

This work was supported by the Welch Foundation (Rice University [TX, USA], C-0627; LJ Wilson), the National Science Foundation‘s Graduate Research Fellowship Program 0940902 (Rice University; JJ Law), and NIH U54 CA136404 (University of Texas Health Science Center [USA]; EM Sevick-Muraca). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Acknowledgements

The authors wish to thank N Wilganowski and H Robinson for performing the in vivo imaging studies.

Additional information

Funding

This work was supported by the Welch Foundation (Rice University [TX, USA], C-0627; LJ Wilson), the National Science Foundation‘s Graduate Research Fellowship Program 0940902 (Rice University; JJ Law), and NIH U54 CA136404 (University of Texas Health Science Center [USA]; EM Sevick-Muraca). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.