Chlorotoxin-conjugated, PEGylated Gd2O3 nanoparticles as a glioma-specific magnetic resonance imaging contrast agent

An enhanced contrast in magnetic resonance imaging (MRI) with high specificity and low toxicity is of great importance in the accurate diagnosis and delineation of gliomas for improved outcomes. In this study, a glioma-targeted contrast agent was designed and prepared by conjugating chlorotoxin (CTX) to poly(ethylene glycol) (PEG) coated Gd2O3 nanoparticles (CTX-PEG-Gd2O3 NPs). The r(1) value of CTX-PEG-Gd2O3 NPs was measured to be 8.41 mM(-1) s(-1), which is higher than that of commercially available Gd-DTPA (4.57 mM(-1) s(-1)). The T-1 contrast enhancement with a prolonged retention period up to 24 h within the brain glioma due to CTX conjugation was demonstrated. Moreover, cell viability and histological analysis verified the low cytotoxicity and the good biocompatibility of CTX-PEG-Gd2O3 NPs. Therefore, our study nominates CTX-PEG-Gd2O3 NPs as a promising glioma-targeted T-1 contrast agent that allows more accurate diagnosis and delineation of brain gliomas.