Theranostic Applications of an Ultra-Sensitive T(1) and T(2) Magnetic Resonance Contrast Agent Based on Cobalt Ferrite Spinel Nanoparticles

SIMPLE SUMMARY: Magnetic nanoparticles (MNPs) represent an important class of nanomaterials that has been actively employed in multiple technological applications. The MNPs and their based composites have been intensively developed for magnetic resonance imaging, targeted drug delivery, magnetic hyperthermia, and other applications. Magnetic Resonance Imaging (MRI) has a prominent position among clinical imaging modalities as it allows for high spatial resolution and tissue specificity without harmful ionizing radiation. The aim of the study was the demonstration of the potential use of magnetic nanoparticles based on cobalt ferrite spinel as advanced MRI contrast agents that are capable of both T(1)-weighted positive and T(2)-weighted negative contrast enhancements in vitro and in vivo. Furthermore, in the present study, we combined novel physical, chemical, and biomedical approaches to develop a multifunctional MRI-detectable drug delivery system that was an efficient T(1)- and T(2)-weighted MRI contrast agent and a nanocarrier for targeted drug delivery in vivo. ABSTRACT: Nano-dimensional materials have become a focus of multiple clinical applications due to their unique physicochemical properties. Magnetic nanoparticles represent an important class of nanomaterials that are widely studied for use as magnetic resonance (MR) contrast and drug delivery agents, especially as they can be detected and manipulated remotely. Using magnetic cobalt ferrite spinel (MCFS) nanoparticles, this study was aimed at developing a multifunctional drug delivery platform with MRI capability for use in cancer treatment. We found that MCFS nanoparticles demonstrated outstanding properties for contrast MRI (r(1) = 22.1 s(–1)mM(–1) and r(2) = 499 s(–1)mM(–1)) that enabled high-resolution T(1)- and T(2)-weighted MRI-based signal detection. Furthermore, MCFS nanoparticles were used for the development of a multifunctional targeted drug delivery platform for cancer treatment that is concurrently empowered with the MR contrast properties. Their therapeutic effect in systemic chemotherapy and unique MRI double-contrast properties were confirmed in vivo using a breast cancer mouse tumor model. Our study thus provides an empirical basis for the development of a novel multimodal composite drug delivery system for anticancer therapy combined with noninvasive MRI capability.