Janus nanoparticles for contrast enhancement of T1–T2 dual mode magnetic resonance imaging

Abstract

The accuracy of magnetic resonance imaging (MRI) scanning can be improved using a multifunctional nanosystem having T₁–T₂ dual contrast enhancement. Specifically, the combination of both T₁ and T₂ effects in a single system helps in acquiring cross validated information during dual mode MRI and reduces the required dose. In this study, polyethylene glycol (PEG) stabilized MnFe₂O₄@MnO Janus nanoparticles were developed as novel dual-mode MR imaging agents. MnO contributed to T₁ contrast whereas MnFe₂O₄ enabled T₂ contrast. The PEG molecules afforded solubility and stability to the contrast agent in water, making it acceptable for biomedical purposes. The biocompatibility of the developed nanosystem was confirmed by cell viability studies. The r₂/r₁ ratio remained at a suitable value, justifying the applicability of the contrast agent for dual mode MRI. Finally, the efficiency of the agent for T₁–T₂ contrast enhancement was confirmed through in vitro and ex vivo MRI experiments.