Nsg10 dlc cantilevers

Atomic force microscopy was performed using a MultiMode 8™ scanning probe microscope (Bruker, Santa Barbara, CA, USA) connected to a NanoScope^® V controller (Veeco, Plainview, NY, USA). The images were obtained using tapping mode in air with NSG10_DLC cantilevers (typical curvature radius 1 nm, resonant frequency 255 kHz, force constant 11.5 N/m) from NT-MDT Spectrum Instruments (Zelenograd, Moscow, Russia). Oligonucleotides containing dodecyl groups were diluted to 1.5 µM in TAM buffer. The reactions were equilibrated for 3 h at 25 °C before 6 µL of this solution was deposited onto a freshly cleaved mica surface (7 × 7 mm, NT-MDT Spectrum Instruments, Zelenograd, Moscow, Russia) and allowed to adsorb for 5 min. The surface was then washed thrice with 200 µL of 18 MΩ grade water and dried by strong argon flow. Samples were dried for 10 min prior to imaging.

An aliquot of dendriplex solution was dropped on a mica slide for 1–2 min. The slide was then washed 3 times with deionized water and air-dried. Scanning was performed in the tapping mode using a Multimode 8 atomic force microscope (Bruker) with NSG10_DLC cantilevers with a tip curvature radius of 1–3 nm (NT-MDT, Russia) at a scanning rate of 3 Hz. Images were processed using Gwyddion 2.36 software.

Dendriplexes were obtained by mixing of solutions of siRNA (1 µM) and dendrimer at charge ratio 1:5. An aliquot of dendriplex solution was deposited onto a mica slide for 1–2 min. The slide was then washed 3 times with deionized H₂O and dried on air. Scanning was performed in tapping mode using Multimode 8 atomic force microscope (Bruker AXS, Karlsruhe, Germany) with NSG10_DLC cantilevers with tip curvature radii of 1–3 nm (NT-MDT, Moscow, Russia), at scanning rate of 3 Hz. Images were processed using Gwyddion 2.36 software (Czech Metrology Institute, Brno, Czech Republic).