SPION Conjugated Curcumin Nano-Imaging Probe: Synthesis and Bio-Physical Evaluation

In this work, we investigated the loading and conjugation of Curcumin on oleic acid (OA) and citric acid (CA) functionalized iron oxide nanoparticles and its applications in improving contrast in MRI. Magnetic iron oxide nanoparticles (Fe₃O₄, MNPs) were synthesized using the co-precipitation method and characterized by XRD, DLS, FT-IR, VSM, and SEM. FT-IR results confirmed functionalization with oleic acid and citric acid. Curcumin was loaded and conjugated with the Nano-Systems and the amount of Curcumin loaded was quantified using spectrophotometry at 419 nm wavelength. The impact of solvent on the loading of Curcumin was studied. The wt% of loaded Curcumin was found to be 0.189 wt% using dimethylformamide (DMF) whereas using a combination of water-ethanol (15% v/v), this increased to 56.149 wt%. T2 relaxation time was determined using a 1.5 Tesla MRI machine; results showed that the MNPs reduced T2. Cytotoxicity of Nano-Systems (NS) in MTT assay showed that concentrations higher than 80 μg/mL (C_NS > 80 μg/mL) could lead to cancer cell death and low concentrations, up to 40 μg/mL (C_NS < 40 μg/mL) could be evaluated for diagnostic purposes.