Synthesis and In Vitro Characterization of Fe(3+)-Doped Layered Double Hydroxide Nanorings as a Potential Imageable Drug Delivery System

Highly dispersed Fe(3+)-doped layered double hydroxide (LDH-Fe) nanorings were obtained by a simple coprecipitation-acid etching approach. The morphology, structure, magnetic resonance imaging (MRI) performance in vitro, drug loading and releasing, Fe(3+) leakage, and cytotoxicity of the as-prepared LDH-Fe nanorings were characterized. The LDH-Fe nanorings showed good water dispersity and a well-crystallized structure. The DLS average size of nanoparticles was measured to be 94.5 nm. Moreover, the MRI tests showed a favourable T(1)-weighted MRI performance of the LDH-Fe nanoring with r(1) values of 0.54 and 1.68, and low r(2)/r(1) ratios of 10.1 and 6.3, pre- and after calcination, respectively. The nanoparticles also showed high model drug (ibuprofen) loading capacities, low Fe(3+) leakage, and negligible cytotoxicity. All these results demonstrate the potential of LDH-Fe nanorings as an imageable drug delivery system.