Relevance between MRI longitudinal relaxation rate and gadolinium concentration in Gd3+/GO/alginate nanocomposite

Relevance between magnetic resonance imaging (MRI) relaxation rate and concentration of magnetic nanoparticles determines the capability of a nanomaterial to provide MRI contrast. In the present study, alginate was conjugated to gadolinium/graphene oxide nanocomposite to form gadolinium/graphene oxide/alginate nanocomposite, aiming to investigate its effect on the relevance between MRI longitudinal relaxation rate and paramagnetic gadolinium concentration. The physicochemical properties of the nanocomposite and its effect on the cell culture were investigated. Moreover, MRI longitudinal relaxation rates were determined based on the corresponding exponential curves, and the graph of their relevance with gadolinium concentration was plotted. The average thickness and sheet size of the nanocomposite were three and 100 nanometers, respectively. The nanocomposite showed high cell viability, even at the relatively high concentration of 75 µg/ml. In addition, a linear correlation was observed between longitudinal relaxation rate and gadolinium concentration. According to the results, the linearity between gadolinium/graphene oxide/alginate nanocomposite and gadolinium concentration, which revealed a high slope, confirmed the potential of the nanocomposite to significantly improve the positive contrast of MR images.