Jem 2100 transmission electron microscopy tem

The average size and size distributions of the formed liposomes were determined by dynamic light scattering (DLS) and nanoparticle tracking analysis (NTA). DLS measurements were performed using a Malvern CGS-3 multiangle goniometer (Malvern Ltd, Malvern, UK) with a JDS Uniphase 22 mW He-Ne laser operating at 632 nm, an optical fiber-based detector and a digital LV/LSE-5003 correlator. Autocorrelation func-tions were analysed by the cumulants method (fitting a single exponential to the correlation function to obtain the mean size and the PDI) and the CONTIN routine (fitting a multiple exponential to the correlation function to obtain the distribution of particle sizes). All measurements were performed at a 90°a ngle. NTA measurements were conducted with a NanoSight LM10SH (NanoSight, Amesbury, UK), equipped with a sample chamber with a 532 nm laser. The samples were injected into the sample chamber with a syringe until the liquid reached the tip of the nozzle and measured for 60 s with a manual shutter and adjustments were made. The zeta potential of the liposomes was measured by a zeta potential analyzer (Malvern Instruments, Malvern, UK) at 25 ± 0.1 °C. The morphology of the liposomes was observed by JEM 2100 transmission electron microscopy (TEM; JEOL, Japan). The samples were negatively stained with 2% phosphotungstic acid (Merck, USA).