Luteinizing hormone-releasing hormone (LHRH) conjugated magnetite nanoparticles as MRI contrast agents for breast cancer imaging

Targeted magnetic resonance imaging (MRI) contrast agents offer platforms for the specific detection of many diseases, including cancer. This study explores the applicability of luteinizing hormone-releasing hormone-conjugated PEG-coated magnetite nanoparticles (LHRH-MNPs) to the enhancement of triple negative breast cancer (TNBC) detection. In vitro MRI studies were first performed, showing the consistent darkening effect of both MNPs and LHRH-MNPs in T2-weighted maps. Using a mouse model with an induced subcutaneous tumor, MNPs and LHRH-MNPs were injected into xenograft MDA-MB-231. This was done through intratumoral and intravenous injections, respectively, enabling direction comparisons of the two nanoparticles. Intratumorally injected LHRH-MNPs maintained T2 signals within the breast tumors up to two weeks, revealing long-term tumor enhancement ability, while the signal started to recover towards the contrast of the original tumor before injection in the case of MNPs at 24 h post injection. For intravenous administration, LHRH-MNPs continued to darken breast tumor 24 h following injection, whereas contrast enhancement was not obvious in animals injected with MNPs. These results show the potential of LHRH-MNPs as negative contrast agents for the specific detection of TNBC.