A hybrid system: MnO-incorporated mesoporous silica nanoparticles for theranostic applications

The need for an alternative ({ T}_{1}) contrast enhancer for magnetic resonance imaging (MRI) has been escalating owing to the toxicity profiles observed with the use of commercial contrast agents. Manganese oxide nanoparticles provide an optimal solution for the problem, as it is an endogenous co-factor for many enzymes in the biological system. In the present work, we have synthesized mesoporous silica nanoparticles encapsulated with manganese oxide nanoparticles as a positive contrast enhancer for MRI applications. Spherical magnetic MnO nanoparticles with divalent oxidation state were also synthesized and utilized as control to compare the efficiency of the nano-hybrid system. MRI showed higher contrast enhancement with the use of nano-hybrid and the relaxivity value for ({ T}_{1})-weighted imaging was calculated to be (2.6~hbox {mg ml}^{-1}~hbox {s}^{-1}). Also, the developed system was validated for its usefulness as a therapeutic system through adsorption studies. Therefore, the nano-hybrid has the potential to be a competent MRI contrast enhancer that could be used for theranostic applications.