TEA-assistant synthesis of MOF-74 nanorods for drug delivery and in-vitro magnetic resonance imaging

Zn-MOF-74 nanorods with uniform diameters of about 200 nm were successfully prepared by a triethylamine (TEA) assistant solvothermal method. The effects of TEA on the sizes and morphologies of nanoscale particles were investigated. Guided by this method, bimetallic ZnxMn1-x-MOF-74s were facilely prepared to endow the nanomaterial with magnetic resonance imaging (MRI) ability. Nanoscale Zn0.7Mn0.3-MOF-74 were successfully produced with homogenous Mn dispersion. Magnetic resonance relaxivity studies using clinical MRI equipment proved that Zn0.7Mn0.3-MOF-74 nanoparticles show a satisfactory r1 relaxivity value of 6.5 mM−1 s−1. The saturated DOX loading capacity of Zn0.7Mn0.3-MOF-74 nanocarriers was evaluated to 113 mg g−1. After chitosan (CS) coating, cytotoxicity experiments showed that [email protected]0.7Mn0.3[email protected] nanocomposites featured adequate biotolerability and no interference with cellular metabolism. These results indicated great potential of the bimetallic ZnMn-MOF-74s as new biomedical materials integrating cellular drug delivery with MR imaging applications.