Imaging of Guerin Carcinoma During Magnetic Nanotherapy

Abstract

We conducted a detailed imaging study of transplanted Guerin’s carcinoma in rats during treatment with magnetic nanotherapy. We show that treatment with magneto-mechano-chemically synthesized magnetic nanocomplexes based on Fe3O4 nanoparticles conjugated with the antitumor agent doxorubicin and followed by irradiation with local electromagnetic irradiation resulted in a better outcome than treatment with conventional doxorubicin or treatment with magnetic nanocomplexes without electromagnetic irradiation. Analysis of magnetic resonance images obtained over time showed that the application of local electromagnetic irradiation did not alter the position of magnetic nanocomplexes in the tumor. B-mode sonography demonstrated that injection of magnetic nanocomplexes into the tumor and subsequent electromagnetic irradiation resulted in increased echogenicity throughout the tumor, which is characteristic of increased blood perfusion. Color Doppler ultrasound imaging showed that the largest decrease of tumor vessel area occurred after injection of magnetic nanocomplex and application of local electromagnetic irradiation. Elastography performed on a diagnostic ultrasound system showed that the injection of magnetic nanocomplexes in tumors increased Young’s modulus for Guerin’s carcinoma compared to tumors not treated with nanoparticles. These results suggest that a theranostics approach-combination MRI together with ultrasound elastography during treatment of tumor may provide a useful method to monitor the effectiveness treatment of cancer patients during magnetic nanotherapy.