Bioactive properties of chitosan stabilized magnetic nanoparticles - Focus on hyperthermic and anti-amyloid activities

The magnetic nanoparticles have great potential in biomedical and clinical applications because of their unique physicochemical properties. We have synthesized magnetite nanoparticles (MNPs) by coprecipitation method followed by their coating with biodegradable, biocompatible and bioactive polysaccharide chitosan. Complex physicochemical characterization of chitosan-coated MNPs (Chit-MNPs) dispersed in water was performed using various methods to determine their structure, morphology, magnetic and bioactive properties. The experimental evaluation of the specific absorption rate (SAR) of both uncoated MNPs and modified Chit-MNPs was made by calorimetric measurements. The SAR values of prepared samples increased with the applied magnetic fields H up to similar to 7.9 kAm(-1). Moreover, the SAR values of Chit-MNPs were higher than those of MNPs demonstrating the possibility of their utilization as nanoheaters for hyperthermic treatment. The bioactivity of Chit-MNPs was investigated to characterize their anti-amyloid properties. The ability of Chit-MNPs to interfere with a-lactalbumin amyloid fibrils (alpha LAF) was studied using ThT assay and AFM microscopy. It was observed that Chit-MNPs are able to destroy alpha-lactal-bumin amyloid fibrils in a concentration-dependent manner.