Malvern zetasizer software

The size of the liposomes and their zeta potential were measured through dynamic light scattering (DLS) and electrophoretic light scattering (ELS) using a Zetasizer Nano ZS from Malvern Instruments^® (Malvern, UK). The protocol was adapted from Hasan et al. [39 (link)]. Empty liposome and SHH2 and SHH3 liposome samples were diluted to one-five-hundredth (1:500) in ultrapure water and then were spotted with a syringe into a zeta cell. An algorithm built into the Malvern^® Zetasizer software (Malvern Instruments, Malvern, UK) analyzed the measured intensity autocorrelation functions. All measurements were made at 25 °C.

Particles size, ζ-potential and the polydispersity index of NPs were determined by dynamic light scattering (DLS) and electrophoretic light scattering (ELS) using a Zetasizer Nano ZS instrument (Malvern-Panalytical, Malvern, UK) and the Malvern Zetasizer software for data analysis. The ζ-potential was calculated using the mixed mode measurement phase analysis light scattering (M3-PALS) technique (Malvern-Panalytical, Malvern, UK). Twenty µL of a 2 µg/µL viral nanoparticles solution were diluted in a Folded Capillary Zeta Cell (for ELS) and in a 12 mm Square Polystyrene Cuvettes (for DLS) to a final volume of 800 µL using a physiological solution (0.9% NaCl). Data were collected at 25 °C for 120 s (for DLS) and 180 s (for ELS) in triplicate. The data reported represent the size by intensity, as diameter of the peaks. All the analyses were performed by IXTAL srl, Novara, Italy.

Transmission electron microscopy (TEM) analyses were performed with a LIBRA 120 PLUS Carl Zeiss SMT electron microscope (Germany) on ultrathin sections (50–70 nm) of the samples embedded in Embed 812 resin and deposited onto copper grids. For magnetoliposomes, drops were placed on copper grids with formvar film and they were stained using negative staining technique. In addition, electron energy loss spectroscopy (EELS) was used to characterize the presence of iron content inside the liposomes. The hydrodynamic particle size of the samples at pH 7 was measured by dynamic light scattering (DLS) using a Nano-ZS apparatus (Malvern Instruments, Worcestershire, UK). For the measurement of electrophoretic mobility, stock suspensions of BMLs and Oxa-BMLs were suspended in flasks containing oxygen-free NaClO₄ 10 mM (final volume of 10 mL/flask), and the pH was adjusted to 7.4. Samples were sonicated for 2 min, and the electrophoretic mobility was immediately measured. ζ-potential values were calculated from these measurements by using Malvern Zetasizer software (Malvern Instruments, UK). All measurements, done in triplicate for each sample, were carried out at 25 °C using disposable plastic cuvettes. Hysteresis cycles were carried out by using a superconducting quantum interference device (SQUID) 5 T magnetometer (Quantum Design MPMS XL, San Diego, CA, USA).