Zetasizer nano s particle size analyzer

The size of nondegraded and degraded DMa particles without and with transition metal ions was determined by dynamic light scattering (DLS) using Malvern Zetasizer Nano S particle size analyzer, (Malvern, UK). DMa samples were diluted in deionized distilled filtered water to concentration 0.1 mg/ml and volume 1 ml.

Multilamellar and/or unilamellar liposomes consisting of POPC (1 mM) alone or POPC (0.95 mM) and POPS (0.05 mM) were prepared according to previously described methods [20 –22 (link)]. Briefly, a mixture of the selected lipids at desired concentration was dissolved in chloroform saturated with argon to prevent oxidation. Chloroform was then evaporated with a stream of argon/nitrogen gas, and the lipid film that formed on the bottom of the test tube was thoroughly dried under reduced pressure for 12 h. A buffer solution was added to the dried lipids at a temperature higher than the main phase-transition temperature of the lipids used (room temperature was appropriate for the lipids used in this work), and the mixture was vortexed vigorously. To obtain unilamellar liposomes, the suspension was extruded using an extruder with needles (cat. no. 610000, Avanti Polar Lipids, Inc.) and filtered using filters with pore diameters of 0.1 μm and 0.2 μm (cat. nos. 610005 and 61006, Whatman, GE Healthcare Ltd., Little Chalfont, UK) above the phase-transition temperature of the lipids. The size distribution and stability of the liposomes were analyzed in 10× dilution using a Zetasizer Nano S particle size analyzer (Malvern Instruments, Malvern, UK).

Dynamic light scattering (DLS)
analyses were performed using a Zetasizer Nano S particle size analyzer
(Malvern Panalytical) with a constant 173 C scattering angle at 25
°C and the laser wavelength of 633 nm. Before DLS analysis, the
buffers (20 mM Tris-HCl, pH 7.5, 0.1 M NaCl, or 50 mM NaAc mM, pH
4.0) were filtered through a sterile syringe filter with 0.22 μm
pore size. The sample volume used for analysis was 80 μL, and
the concentration of ScDyPB was 1.5 μM. The
scattering intensity data were processed using instrumental software
to obtain the hydrodynamic diameter (D_h) and the size distribution of scatters in each sample.