Paramagnetic Nanoparticles as Contrast for Magnetic Resonance Imaging in Acute and Chronic Kidney Diseases: An Experimental Study

Background: Magnetic Resonance Imaging (MRI) is a non-invasive technique to evaluate soft tissues with high spatial resolution, allowing differentiation between tissues through contrast. Gadolinium (CPGd), the contrast agent currently used, is contraindicated in patients with severe renal failure. Therefore, developing new biocompatible contrast agents is crucial to minimize adverse effects. In this context, paramagnetic nanoparticles (NPPs) are ideal for such applications. To evaluate the nephrotoxicity of NPPs in experimental acute and chronic renal failure models in male and female rats. Methods: Male and female Wistar rats were subjected to bilateral renal ischemia for 45 (male) and 30 (female) minutes and reperfusion (I/R) and 5/6 nephrectomy (Nx 5/6). After the recovery period, saline solution (control), CPGd (0.100 mmol/kg), or NPPs (0.175 mmol/kg) were infused by tail vein. Renal function and hemodynamic measurements were evaluated after 24 hours and 14 days. Results: In rats, the I/R model, urinary excretion of NPP was 20% compared to CPGd (100%). The results of blood pressure and kidney function are found in Fig. 1. The NPP image showed positive contrast in the renal calyx and bladder after 15 min of injection in the I/R model (Fig. 2). Conclusion: The results suggest promising use of NPPs in renal disease patients, although increased serum creatinine levels were observed after 24 hours in females. Further studies are needed to evaluate the elimination of NPPs. Funding: Government Support – Non-U.S.Renal calyx (yellow) and bladder (blue arrow).