Within area A3 Interactions and dynamics of multi-cellular systems, tissues and other complex systems we tested the properties of the new contrast agent based on cobalt ferrite nanoparticles for MR imaging, where cobalt ferrite nanoparticles (tested in 1% agarose) were used as positive T1 and negative T2 MRI contrast agents due to their special relaxation properties. With this study we were involved in the outstanding publication in the journal Nature nanotechnology.
COBISS.SI-ID: 25057831
NMR modulated gradient spin echo (MGSE) was used to characterize the translational dynamics of polymer segments via the measurement of the segmental velocity autocorrelations, which were expressed according to Rouse and deGennes the tube/reptation model and show nice agreement with the measurements on the molten polybutadiene and polyethylene - a first direct experimental verification of the snake-like motion in a "tube" of entangled polymer chains. This new understanding of macromolecular motion enables to explain also the unusual results of our previous MGSE measurement of bulk water as a kind of Rouse type motion in a network of hydrogen bonds in water. The same method has been applied also to provide the information about molecular self-diffusion in nanopores tested on the sieve of polyamide membrane.
COBISS.SI-ID: 2362212
A serious drawback of ESR, particularly in its application to cells, is the lack of information on the location of spin probes in the system. In order to realize real time tracking, a spin probe was combined with a fluorophore in a new kind of nitroxide-fluorophore double probe which, in addition to information about lipid dynamics, enables visualization by fluorescence microscopy. The two sets of probes synthesized are based on an amino-alkyne-functionalized sugar that serves as a central polar group and as a linker between the 7-nitrobenz-2-oxa-1,3-diazol-4-yl (NBD) fluorophore and the derivative of the spin labelled fatty acid. In this setting, the location of the fluorophore is restricted to the water-lipid interface, while the nitroxide is located deep in the lipid bilayer. Preliminary tests on cells show preferential localization of both probes in the plasma membrane, with a relatively slow redistribution to other membranes of the cell. We believe that such double probes would be particularly useful for studies of plasma membrane heterogeneity and associated cellular processes.
COBISS.SI-ID: 3007601