ABSTRACT
Superparamagnetic iron oxide nanoparticles are widely used for the magnetic resonance imaging (MRI) applications. The surface characteristics, magnetic properties, size and targeting efficiency of the material are crucial factors for using the same as contrast agents. We report a simple synthesis method of citrate coated iron oxide nanoparticles and its systematic characterization. The developed system is highly water dispersible with an average particle size of 12 nm. The particles in water are monodisperse and are found to be stable over long periods. The efficiency of the material to de-phase water proton has been studied for various concentrations of iron using longitudinal (T1) and transverse (T2) weighted MRI. The coating thickness of the nanoparticle was optimized so that they exhibited a high transverse to longitudinal relaxivity (r2/r1) ratio of 37.92. A clear dose-dependent contrast enhancement was observed in T2 weighted in vivo MR imaging of liver fibrosis model in rodents. The labelling efficacy of the particle and the intracellular magnetic relaxivity were also investigated and presented. The particles were also tested for blood and cellular compatibility studies. Development of fibrosis and presence of iron in the liver was confirmed by histopathological analysis. From this study, we conclude that the citrate coated ultra small superparamagnetic iron oxide nanoparticles (C-USPION) with optimized parameters like particle size and magnetic property are capable of producing good MR contrast in imaging of liver diseases.
Subject(s)
Citrates , Ferric Compounds , Liver Cirrhosis/diagnosis , Magnetic Resonance Imaging , Nanoparticles , Animals , Cell Communication , Cell Line, Tumor , Disease Models, Animal , Humans , Liver Cirrhosis/pathology , Male , Nanoparticles/ultrastructure , Particle Size , Platelet Aggregation , Rats, Wistar , Reproducibility of Results , Spectroscopy, Fourier Transform Infrared , Thermogravimetry , X-Ray DiffractionABSTRACT
Ayurveda is an Indian system of medicine. Despite clinical efficacy, lack of scientific validation has limited the effective use of Ayurvedic drugs. Cardoguard is an Ayurvedic antihypertensive drug formulated by Nagarjuna Herbal Concentrates Ltd., Kerala, India. Left ventricular hypertrophy (LVH) is a modifiable risk factor, and regression of LVH reduces the propensity for adverse cardiovascular events. This study was taken up with the objective of evaluating the efficacy of Cardoguard in the prevention of cardiac remodeling. Cardoguard was administered orally to 2-month-old spontaneously hypertensive rats for 4 months at a dose of 5 mg·day(-1). The dose corresponds to the therapeutic dose calculated on the basis of body surface area. Lower hypertrophy index, decrease in cardiomyocyte area, and reduction of interstitial fibrosis in treated spontaneously hypertensive rats indicate amelioration of cardiac hypertrophy by Cardoguard. Cardiac output increased in response to treatment. Immunostaining for the phosphorylated components of major signaling pathways associated with hypertrophy suggests that prevention of LVH by Cardoguard is possibly mediated through inhibition of extracellular signal-regulated kinases and protein kinase C-ε signaling pathways. Reduced expression of 3-nitrotyrosine in response to the treatment suggests that prevention of cardiac remodeling by Cardoguard is mediated by reduction of oxidative stress.