Targeted imaging of brain gliomas using multifunctional Fe3O4/MnO nanoparticles†
Integrating T1- and T2-components of magnetic resonance (MR) imaging into a single particle has been demonstrated to be effective for improving the diagnostic accuracy. However, a T1–T2 dual modal MR contrast agent with glioma targeting ability remains unexplored. In this study, we prepared gourd-shaped Fe3O4/MnO hybrid NPs with a size of 25 nm through a thermal decomposition method. The water dispersibility was then obtained via a ligand exchange process with carboxylic acid-terminated silane. The sequential conjugation of chlorotoxin (CTX) and Cy5.5 on the carboxyl groups of attached silane endowed Fe3O4/MnO hybrid NPs with near-infrared fluorescence and glioma-targeting characteristics. The in vitro studies confirmed the targeting ability of Fe3O4/MnO–Cy5.5–CTX NPs toward C6 glioma cells. The in vivo T1–T2 dual modal MR imaging of glioma-bearing brain verified that the CTX conjugation led to a better contrast enhancement of the tumour tissue from the normal tissue both in T1 and T2 imaging, comparing to unconjugated NPs, which could enable more accurate diagnosis of gliomas.