Multiuser equipment approved in grant # 2014/14457-5: particle tracking analyzer and zeta POTENTIAL/DYNAMIC light scattering

Abstract

The NanoSight NS300 Nanoparticle Tracking Analyzer and the Zeta sizer Nano ZS90 Dynamic Light Scatter are equipments based in complementary techniques, both being essential in the characterization of micro and nanoparticule systems such as the lipid-based drug-delivery systems for local anesthetics. The parenteral administration of those requires controlled sizes (< 500nm), low polydispersity (> 0.3) while high Zeta potentials (> 20-30 mV, in modulus ) are necessary to guarantee enough shelf-life for the pharmaceutical formulation. The equipments will be used not only by our research team (thematic project), but also by research groups from the institutes of Biology, Chemistry and Faculties of Chemical Engineering and Pharmacy of Unicamp, to characterize micro and nanometric samples in nanobiotechnological products such as gene and drug delivery. They are multiuser equipments of top interest for researchers belonging to Unicamp and other research centers at São Paulo state and Brazil, to whom the use is assured by the share-used plan attached to this proposal. The NanoSight NS300 is a Nano Tracking Analysis (NTA) equipment that allows one to measure the size, polidispersity, surface electric potential and concentration of particles (1nm - 5 microm) in suspension through photo correlation spectroscopy coupled to video microscopy. The photo correlation spectroscopy provides NTA with the unique feature of measuring the concentration of particles and molecular weight. Another technological distinctive feature of the Nanosight equipment is the ability to measure individual particles, in a different way than dynamic light scattering (DLS) equipments, that take into account the average Brownian motion of the particles. This, in a polydisperse system can give misleading average size measures, even when only a small population of particles presents a dissimilar size. As for the Zeta sizer Nano ZS90, it is a 90º geometry DLS that is able to measure size (2nm a 6 microm) and polidispersity of nanoparticulate systems and also the Zeta potential, by the direct measure of the electrophoretic mobility (in a different manner than the Nanosight NS300 that calculates Zeta from the Doppler shift caused by the electrophoretic mobility of the particles). So the Zeta sizer is the most robust equipment available in the market and often cited in scientific publications in the field. (AU)