G250 2 mica sheets

Morphological examination of both niosome formulations was performed by atomic force microscopy (AFM). Each formulation (5 -10µL) was deposited onto freshly cleaved mica surfaces (G250-2 Mica sheets 1" x 1" x 0.006"; Agar Scientific Ltd., Essex, UK), and left in to air dry for 1 h before AFM imaging. The images were obtained by scanning the mica surface in air under ambient conditions using a Dimension FastScan BioAFM (Bruker, CA, USA) operated on Peak Force QNM mode. The AFM measurements were obtained using ScanAsyst-air probes. AFM images were collected by random spot surface sampling (at least three areas). The analyses were performed using the Nanoscope Analysis v1.4 (Bruker, USA).

The particle size and zeta potential of the sample preparations were analysed using dynamic light scattering photon correlation spectroscopy (Malvern Zetasizer Nano-ZS, Malvern, UK). Firstly, sample dispersions were adequately diluted to 0.1 mg/mL with de-ionised water and then particle size was measured in triplicate. After that sample were transferred into a zeta-cuvette and the net charge present on the particle were again evaluated in triplicates. The z-average and PDI values were applied for the evaluation of the particle size.
2.2.5. Atomic Force Microscopy (AFM)
AFM analysis was conducted using freshly prepared SLN formulations; approximately 3 µL was deposited on the freshly cleaved mica surface (G250-2 mica sheets 1" x 1" x 0.006"; Agar Scientific Ltd, Essex, UK), and allowed to dry for 1 hour (h) at room temperature prior to AFM analysis. Then the images were obtained by scanning the mica surface under ambient conditions using a PeakForce QNM Scanning Probe Microscope (Digital Instruments, Santa Barbara, CA, USA; Bruker Nanoscope analysis software Version 1.40). AFM scanning was done using ScanAsyst-air probes, with tip radius of 2 nm and spring constant of 0.67 N/m; nominal 0.4 N/m). The images were collected from two different formulations by random spot surface sampling at five different areas.

Morphological examination of the NISV was performed by atomic force microscopy (AFM). Five µL of each formulation was deposited onto freshly cleaved mica surfaces (G250-2 Mica sheets 1" x 1" x 0.006"; Agar Scientific Ltd., Essex, UK), and air dried for ~1 h before AFM imaging. The images were obtained by scanning the mica surface in air under ambient conditions using a Dimension FastScan BioAFM (Bruker, CA, USA) operated on Peak Force QNM mode. The AFM measurements were obtained using ScanAsyst-air probes; the spring constant was calibrated by thermal tune (0.52 N m -1 ; Nominal 0.4 N m -1 ) and the deflection sensitivity calibrated using a silica wafer. AFM images were collected by random spot surface sampling (at least three areas). The analyses were performed using the Nanoscope Analysis v1.4 (Bruker, USA).

AFM was employed using a TT-2 AFM (AFMWorkshop, US) to provide a visual indication of liposome morphology and distribution. A volume of 10 μl from each formulation was diluted with 1800 μl of PBS, then 15 μl of this dilution was placed on a freshly cleaved mica surface
(1.5 cm × 1.5 cm; G250-2 Mica sheets 1″ × 1″ × 0.006″; Agar Scientific Ltd., Essex, UK). The sample was then air-dried for ∼30 min and imaged at once by scanning the mica surface in air under ambient conditions. The AFM measurements were obtained using Ohm-cm Antimony doped Si probes, frequency range 50 -100 kHz. AFM scans were acquired at a resolution of 512 × 512 pixels at scan rate of 0.6 Hz.

For AFM experiments, 3 µL of RTA loaded and unloaded SLN were deposited onto a freshly cleaved mica surface ((G250-2 mica sheets 1" x 1" x 0.006"; Agar Scientific Ltd, Essex, UK), and left to dry for 1 h before AFM imaging. The images were obtained by scanning the mica surface, in air, under ambient conditions using a PeakForce QNM Scanning Probe Microscope (Digital Instruments, Santa Barbara, CA, USA; Bruker Nanoscope analysis software Version 1.40). The AFM measurements were obtained using ScanAsyst-air probes, and the spring constant (0.67 N/m; nominal 0.4 N/m) and deflection sensitivity were calibrated, but not the tip radius (a nominal value of 2 nm was used). Surface roughness (Ra) values were determined by entering surface scanning data into a digital levelling algorithm (Bruker Image Analysis Nanoscope Analysis software V 1.40). AFM images were collected from two different samples by random spot surface sampling (at least five areas).

A volume of 5 µl from each formulation was placed on a freshly cleaved mica surface (1.5 cm x 1.5 cm; G250-2 Mica sheets 1" x 1" x 0.006"; Agar Scientific Ltd., Essex, UK). The sample was then air-dried for ~30 min and imaged at once by scanning the mica surface in air under ambient conditions using a Bruker MultiMode 8 Scanning Probe Microscope (Digital Instruments, Santa Barbara, CA, USA) operated on Peak Force QNM mode. The AFM measurements were obtained using ScanAsyst-air probes; the spring constant was calibrated by thermal tune (Nominal 0.4 N m -1 ) and the deflection sensitivity calibrated using a silica wafer. AFM scans were acquired at a resolution of 512 x 512 pixels at scan rate of 1 Hz, and produced topographic images of the samples in which the brightness of features increases as a function of height. AFM images were collected from random spot surface sampling.