Jpk nanowizard 2

Surface roughness was assessed using an atomic force microscope (JPK Nanowizard II, Bruker, Germany) (Figure S2b). The surface roughness parameters recorded were (a) Ra (roughness average), the arithmetic average of the absolute values of the profile heights over the evaluation length, and (b) Rq (RMS roughness), the root mean square (RMS) average of the profile heights over the evaluation length. Measurements were randomly taken at multiple sample points and then the mean was calculated.

All crystals were glued to cantilever (Arrow TL- 1, Nanoworld) with epoxy (21 (link)) at least 12 h before use. All attraction forces between cell and crystal were measured with JPK CellHesion (JPK) (23 (link)). Briefly, the measurement was carried in the relative force feedback contact/tapping mode (IP gain: 50 Hz; IG gain: 0.001 Hz; correct baseline: 1; relative set point: 0.5 nN; z length: 50 µm; extend delay: 0 s; constant height). Data were analyzed with JPK Data Processing. Maximum binding forces were calculated and plotted. Each dot presents a single measurement.
Attraction forces between crystal and lipid monolayer were measured with JPK NanoWizard II (JPK). All set up was the same as the JPK CellHesion except z length was 10 µm. AFM scanning mode was used to confirm domain formation.

An atomic force microscope JPK NanoWizard II (JPK Instruments) was used to acquire images of pDR1m samples. An Axio Observer Z1 microscope (Zeiss) was combined with the AFM to control tips and sample position. Silicon nitride probes (MLCT, Bruker), with a spring constant of 0.01 N/m, were used in contact mode, in air, and at room temperature. Raw images were corrected by the JPK data processing software using a standard procedure (flatten, plane-fit, and artifact lines caused by the tip attachment and removal). The scale indicating the sample height or deflection was adjusted to limit the gap between high and low regions.

The internal structure of PEG-Arg@IONPs was studied through transmission electron microscope (Cambridge 360–1990 Stereo Scan Instrument-EDS) measurements.
Morphology of PEG-Arg@IONPs was studied by atomic force microscopy (AFM) (JPK Nano wizard II, JPK instrument, Bouchestrasse, Berlin, Germany) in an intermittent contact mode.
X-ray diffraction was measured by a Bruker AXS model D8 Advance powder X-ray diffractometer.
FTIR spectra of the sample were measured by a Bruker, Tensor 27 FTIR spectrophotometer.
To evaluate the behavior in reaction to the increased temperature, thermogravimetric analysis (TGA, Linseis Instruments model, STA PT 1000, USA) and also, differential scanning calorimetry (DSC, Mettler Toledo, model Star SW 9.30, Schwerzenbach, Switzerland) were used.
Sample magnetization curves were attained by means of a vibrating sample magnetometer (VSM Magnetic Daghigh Daneshpajouh Co, Kashan, Iran).
ζ-potential and hydrodynamic size measurements were done using a nano/zetasizer (Malvern Instruments, Worcestershire, UK, model Nano ZS).
To quantify the stability of PEG-Arg@IONPs nanoparticles dispersed in water, DMEM, and saline, respectively, UV-visible absorbance at 450 nm were used in order to monitor the absorbance of the corresponding dispersion solution containing PEG-Arg@IONPs nanoparticles at a fixed wavelength similar to that in the reported study.

Mechanical unfolding of Omps was performed as described^{44 (link)}. Briefly, 1 µL of OMV solution was adsorbed to freshly cleaved mica supports in 75 µL DPBSS for 20 min at room temperature. Samples were washed with DPBSS several times. All AFM measurements were performed on a JPK NanoWizard II (JPK Instruments) using OMCL-RC800PSA cantilevers (Olympus). Cantilevers were calibrated using the thermal noise method^{64 (link)}. Adsorbed OMVs were located by imaging in contact mode, followed by force spectroscopy measurements using a contact force of ≈750 pN for 0.5 s, followed by retraction at constant velocity of 2 µm s^–1. SMFS experiments were performed over several days, using a new sample and new AFM cantilever every day

The topographic characteristics of the enamel surface were assessed using AFM. One sample of each group was used for AFM (JPK Nanowizard II apparatus, JPK Instruments, Berlin, Germany) in tapping mode along with a nonconductive silicon nitrite cantilever (Acta-Probe, APPNano, CA, USA) and a piezoelectric scanner. Scanning frequency was 1 Hz and the spring constant was 13 N/m. The mean surface roughness was measured in five areas (each measuring 5 × 5 μm) using the formula below [23 (link)]. The results were recorded in nanometres (nm).
$$\mathrm{Ra}=\frac{1}{N}{\sum }_{i=1}^N\left|Z_i-\overline{Z}\right|$$
Where N is the number of points assessed and Zi-Z is the height relative to the middle surface [23 (link)]. The mean hardness was calculated for each sample.