Near-infrared imaging of intraperitoneal ovarian cancer enhanced by BrCy112 in a dual mode (MR and NIR), dual-Gd nanoparticle

Abstract

Dual-Mode-Dual-Gd (DMDG) nanoparticles incorporating BrCy112, a brominated carbocyanine dye, were investigated for their potential in magnetic resonance (MR) and optical imaging of intraperitoneal ovarian tumors in an animal model two days post-intravenous injection. DMDG nanoparticles were synthesized using either BrCy112 or indocyanine green (ICG) as the near-infrared (NIR) fluorophore, combined with positive contrast MR imaging agents. The optical properties of these fluorophores were characterized through absorption and fluorescence (FL) spectroscopy, with their loading concentrations optimized in liposomal formulations. MR relaxivity and FL intensity were assessed in vitro, while in vivo imaging was performed on mice bearing human intraperitoneal ovarian cancer xenografts. BrCy112 exhibited approximately 2.5 times greater FL intensity than ICG in deionized water (p < 0.05, n = 5), and in optimized liposomal formulations, DMDG-BrCy112 demonstrated nearly three times higher FL intensity than DMDG-ICG (p < 0.05, n = 5). MR imaging showed enhanced tumor signals following DMDG-BrCy112 and DMDG-ICG injection. Open abdomen and excised tumor analyses revealed that tumors in mice injected with DMDG-BrCy112 had twice the FL intensity (radiant efficiency) per g tumor compared to those injected with DMDG-ICG (p < 0.05, n = 6). These results suggest that BrCy112 exhibits superior FL intensity over ICG, and when formulated in DMDG nanoparticles, it enables MR and NIR imaging days after a single injection. This highlights its potential clinical application for pre-surgical planning and image-guided resection of intraperitoneal ovarian cancer.