Showing papers by "Martina Koneracka published in 2020"
TL;DR: It is found that the AA coating affects the size of dispersed particles and isoelectric point, as well as the zeta potential of AA–MNPs differently, depending on the AA selected, and it is shown that a change in hydrodynamic diameter results in a change to the relaxivity of AA-MNP complexes.
Abstract: In this study, we analysed the physico-chemical properties of positively charged magnetic fluids consisting of magnetic nanoparticles (MNPs) functionalised by different amino acids (AAs): glycine (Gly), lysine (Lys) and tryptophan (Trp), and the influence of AA–MNP complexes on the MRI relaxivity. We found that the AA coating affects the size of dispersed particles and isoelectric point, as well as the zeta potential of AA–MNPs differently, depending on the AA selected. Moreover, we showed that a change in hydrodynamic diameter results in a change to the relaxivity of AA–MNP complexes. On the one hand, we observed a decrease in the relaxivity values, r1 and r2, with an increase in hydrodynamic diameter (the relaxivity of r1 and r2 were comparable with commercially available contrast agents); on the other hand, we observed an increase in r2* value with an increase in hydrodynamic size. These findings provide an interesting preliminary look at the impact of AA coating on the relaxivity properties of AA–MNP complexes, with a specific application in molecular contrast imaging originating from magnetic nanoparticles and magnetic resonance techniques.
16 citations
TL;DR: It is found that the molecular weight of dextran has a significant effect on the particle size, efficiency, magnetic properties and specific absorption rate, which will aid the development of functionalised magnetic nanoparticles for hyperthermia and MRI applications.
Abstract: Dextran-coated magnetic nanoparticles are promising biocompatible agents in various biomedical applications, including hyperthermia and magnetic resonance imaging (MRI). However, the influence of dextran molecular weight on the physical properties of dextran-coated magnetic nanoparticles has not been described sufficiently. We synthesise magnetite nanoparticles with a dextran coating using a co-precipitation method and study their physical properties as a function of dextran molecular weight. Several different methods are used to determine the size distribution of the particles, including microscopy, dynamic light scattering, differential centrifugal sedimentation and magnetic measurements. The size of the dextran-coated particles increases with increasing dextran molecular weight. We find that the molecular weight of dextran has a significant effect on the particle size, efficiency, magnetic properties and specific absorption rate. Magnetic hyperthermia measurements show that heating is faster for dextran-coated particles with higher molecular weight. The different molecular weights of the coating also significantly affected its MRI relaxation properties, especially the transversal relaxivity r2. Linear regression analysis reveals a statistically significant dependence of r2 on the differential centrifugal sedimentation diameter. This allows the targeted preparation of dextran-coated magnetic nanoparticles with the desired MRI properties. These results will aid the development of functionalised magnetic nanoparticles for hyperthermia and MRI applications.
11 citations
TL;DR: It was observed that Chit-MNPs are able to destroy α-lactalbumin amyloid fibrils in a concentration-dependent manner, demonstrating the possibility of their utilization as nanoheaters for hyperthermic treatment.
10 citations