Nsc15

For SEM and energy dispersive X-ray spectroscopy (EDX) investigation, the samples previously sectioned with an IsoMet 1000 (Buehler) microtome at 1 mm, were covered with gold, for a better visualization. SEM and chemical analysis of local area by EDX were carried out with a FEI Quanta 3D FEG (FEI Company, Hillsboro, OR, USA) dual beam microscope. AFM was used to investigate the nano-structural changes within the enamel and dentine at several treatment times. The investigation was performed on a JSPM 4210 Scanning Probe Microscope (Jeol, Tokyo, Japan), using the intermittent contact—tapping mode. The used cantilevers are NSC 15 type MikroMasch (Sofia, Bulgaria), and exhibit a resonant frequency of 325 kHz and a force constant of about 40 N/m. The topographic images were recorded at a scanned area of 2.5 × 2.5 μm to assure an optimal view of the structures at the nano level. The scanning rate vary from 1 to 1.5 Hz. The images were processed in the standard manner using Jeol Win SPM (version 2.0). The roughness (Ra and Rq) and nano-particles diameter were measured with the soft for each image.

Nucleosomal arrays and recombinant hHP1β were dialyzed against SFM buffer (5 mM triethanolamine (pH7.5), 50 mM NaCl, 0.1 mM EDTA). The recombinant proteins at different concentrations (between 0 and 5 μM) were preincubated with oligonucleosomes at a DNA concentration of 50 ng ml⁻¹ in SFM buffer for 1 h at 4°C, and the samples were fixed with 0.05% (v/v) fresh glutaraldehyde (Electron Microscopy Sciences, PA, USA) at 4°C overnight. Fixed samples were extensively dialyzed against TEAE buffer (5 mM triethanolamine (pH 7.5), 0.1 mM EDTA). 10 μl of dialyzed sample was deposited on ca. 1 cm² of freshly cleaved mica (Plano). After 5 min incubation at RT, the mica was washed with 200 μl of water (high-performance liquid chromatography grade) and air-dried. Images were recorded in air on a Nanoscope V Multi Mode scanning force microscope (Veeco, NY, USA) using an ‘E'-scanner with maximum scan size of 15 × 15 μm and silicon-etched probe tips with a typical spring constant of 40 N m⁻¹ and a typical resonance frequency of 325 kHz (NSC15, MikroMasch) in tapping mode.

The ethanol suspensions were sonicated for 1 min, dropped onto 1 mm quartz slides, and dried at room temperature. Height and phase maps were taken with a Bruker Dimension ICON AFM with a silicon SPM probe (MikroMasch NSC15) while tapping in air. Maps were flattened using a first- or second-order fit for each line scan and analyzed using Bruker Nanoscope Analysis.
The heights and diameters of at least 100 individual particles were measured for each sample to construct a reasonable particle size distribution. Particle diameter was approximated by treating the area of the particle as the area of a circle. Height was taken to be the difference of the maximum measured height and the surrounding height.

A 40μl vesicle solution, diluted in MilliQ water to a final concentration of a few μg/ml, was deposited onto freshly cleaved mica, incubated for 20 min, and gently dried under nitrogen flow. Tapping mode AFM measurements were carried out by using a Nanowizard III scanning probe microscope (JPK Instruments AG, Germany) equipped with a 15 μm z-range scanner and NSC-15 (Mikromasch) cantilevers (spring constant 40 N/m, typical tip radius 8 nm); 2 × 2 μm² images were acquired at 256 × 256 pixel resolution. Setpoint was fixed at 70% of free oscillation amplitude (20 nm). Other measurements were performed in liquid by quantitative imaging upon deposition on a functionalized substrate (see supporting information, Supplementary Figure S3).

The AFM measurements were conducted in the AC mode by NanoWizard 3 (JPK) with cantilever of the type NSC15 (MikroMasch).

Atomic Force Microscopy images were captured by using a Nanowizard III scanning probe microscope (JPK instruments, AG Germany) equipped with a 12 μm scanner. Nanoalgosomes were initially concentrated by ultracentrifugation and resuspended in MilliQ water to a final concentration of 5 × 10¹¹ particles/ml, as previously estimated by NTA.
For measurements on dry samples, a 30 μl drop of the samples was directly deposited on freshly cleaved mica, incubated for 10 min, and then gently dried under nitrogen flow. Measurements were performed in tapping mode by using a NSC‐15 (Mikromasch) cantilever (spring constant 40 N/m, typical tip radius 8 nm). Measurements with softer cantilevers (data not shown) were carried out with MSNL‐10 cantilevers (Bruker; lever D, spring constant 0.03 N/m, nominal tip radius 2 nm).