AFM Imaging of TAT-HA-Prdx6 Analog-loaded NPs

AFM imaging and image analysis of TAT-HA-Prdx6 analog-loaded NPs were performed at the Nanoimaging core facility of the University of Nebraska Medical Center, Omaha, NE, USA. In brief, freshly cleaved mica was altered with the treatment of APS (1-(3-aminopropyl) silatrane) as described previously [75 (link),76 (link)]. The TAT-HA-Prdx6 analog-NPs samples were diluted in water and deposited onto APS treated mica for 2 min. The samples were rinsed with deionized water and dried with a gentle flow of argon. The image was recorded with the Multimode Nanoscope IV system (Bruker Instruments, Santa Barbara, CA, USA) in Tapping Mode at ambient conditions. Silicon probes RTESPA-300 (Bruker Nano Inc., CA, USA) with a resonance frequency of ≈300 kHz and a spring constant of ≈40 N/m were applied for imaging at scanning rate of 0.5–1.0 Hz. Images were processed using the FemtoScan software package (Advanced Technologies Center, Moscow, Russia). The size of nanoparticles was measured automatically with Enum features or manually with the Cross-section tool in the FemtoScan program.