Zetasizer nano series zs90

NPs were characterized by transmission electron microscopy (TEM), dynamic light scattering (DLS), and electrophoretic light scattering (ELS). All dispersions of NPs were diluted 10 times before to be applied to a carbon film-covered copper grid. PTA solution (1% w/v) was used as contrast color. The samples were dried and then examined under a TEM JEOL 1010 electron microscope and photographed at an accelerating voltage of 64 kV.
DLS and ELS analyses were performed with a Zetasizer Nano series ZS90 (Malvern Instruments, Malvern, UK) equipped with a JDS Uniphase 22mW He-Ne laser operating at 632.8 nm, an optical fiber-based detector, a digital LV/LSE-5003 correlator, and a temperature controller (Julabo water bath) set at 25°C.
The hydrodynamic diameter of the particles (Zh) and the particle size distribution (polydispersity index, PDI) were analyzed using the ALV-60X0 software V.3.X provided by Malvern. The ζ potential, indicating the electric charge on the NPs surface and the physical stability of the formulations, was calculated by the Helmholtz-Smoluchowsky equation using the same instrument.

D_h (estimated by intensity size distribution and Z-average), the S.D. of each size population (a measure of the size population width; expressed in nm) and the PdI of the different NPs were measured by means of DLS (Zetasizer Nanoseries ZS90, Malvern Instruments, Malvern, UK). Samples were pre-tested using different concentrations to minimize particle–particle interactions and multiple light scattering that may lead to sizes that are larger than the actual ones, as recommended in the ISO 22412:2017 [43 (link)]. Results are presented as a mean value of three independent measurements and each analysis is the result of at least five runs.

The morphologies and sizes of MSNbs, GSNbs, and GNSbs were observed using surface (JEOL, JSM-7600F, Tokyo, Japan) and transmission electron microscopy (JEOL, JEM-752000EX II, Tokyo, Japan). Particle size and Zeta potential were measured via the dynamic light scattering method (DLS; Malvern Zetasizer Nano Series, ZS90, Worcestershire, UK). The MSNBs’ and GNSBs’ chemical structures were studied using Fourier transform infrared spectroscopy (Spectrum 100FT-IR Spectrometers, PerkinElmer, Waltham, MA, USA). The powder X-ray diffraction (XRD) patterns were extracted with an X-ray diffractometer (XRD, Rigaku D/max 2500 XRD, Tokyo, Japan) with Cu-k α radiation and λ = 1.54178 Å.

Nanoparticle maximum absorption wavelengths were obtained using the Varian Cary 50 Bio UV-Visible Spectrometer (McKinley Scientific). Nanoparticle size and zeta potential measurements were obtained using the Zeta-Sizer Nanoseries ZS90 (Malvern Instruments, Worcestshire, UK). Hydrodynamic size based upon Brownian motion was measured in phosphate buffered saline (PBS) solution using DLS (dynamic light scattering). Shape and size were also previously determined using scanning electron microscope (SEM), with the presence of lipids on the particle cores confirmed using a Fourier transform infrared (FTIR) spectroscopy [18 (link)].

Particle size, polydispersion index (PDI), and the ζ-potential of niosomes were measured by dynamic light scattering using a Zetasizer Nanoseries ZS90 (Malvern Instrument, Worcestershire, UK) at an angle of 90 in 0.01 m width cells at 25 ± 1 °C. Colloidal suspensions were properly diluted with distilled water in order to avoid scattering phenomena. Each sample was analyzed in triplicate. The morphology was evaluated using a transmission electron microscope (CM12 TEM, PHILIPS, Amsterdam, The Netherlands), which was equipped with an OLYMPUS Megaview G2 camera (Segrate, Italy). The samples were analyzed at 80 kV. For TEM analysis, a drop of the vesicle dispersion was placed onto a Cu/C grid and stained by adding a drop of 2% (w/w) uranyl acetate solution; the excess solution was removed using filter paper, followed by a thorough air-drying.