MnAl-Layered Double Hydroxide Nanosheets Infused with Fluorouracil for Cancer Diagnosis and Therapy

Abstract

Nanotheranostic materials with a layered double hydrotalcite (LDH) structure, containing manganese as a contrast agent for MRI and fluorouracil (FU) as a model anticancer drug, were prepared. The manganese was rationally included in the two-dimensional (2D) LDH construction by co-precipitation (CP) at low suprasaturation at a theoretic Mn/Al ratio of 2. The anticancer drug was strategically introduced in the layered solid by two synthetic approaches, that is, CP at low suprasaturation and CP coupled with ion exchange (IE). The materials were extensively characterized for their composition, structure, texture, morphology, and oxidation state by AAS, XRD, N2 physisorption, FT-IR, SEM, TEM, TGA, DR UV−vis, and XPS. The results of physicochemical characterization revealed high-quality 2D materials in which manganese mainly exists as Mn2+ and Mn3+ while the mass loading of FU was 6.96 and 5.28% for the samples prepared by CP and CP coupled with IE, respectively. The nanomaterials exhibited high r1 and r2 relaxivities, particularly at pH = 7.4. The mathematical models used to fit the experimental data revealed a quasi-Fickian diffusion of the FU release from MnAl-LDH.