Example 11
IR spectra of the polymer nanocapsules were obtained on a PerkinElmer Paragon 1000 FT-IR spectrometer. UV-Visible spectra were acquired with a GeneSys 6 spectrometer (Thermo Scientific). Fluorescence spectra were obtained with a QuantaMaster Spectrofluorimeter (Photon Technology International). TEM images of nanocapsules were obtained on a Philips EM120 TEM at 100000× (see, e.g.,
Before observation, siRNA nanocapsules were negatively stained using 1% pH 7.0 phosphotungstic acid (PTA) solution. Zeta potential and particle size distribution were measured with a Malvern particle sizer Nano-ZS. SEM images of nanocapsules were obtained with a JEOL JSM-6700F SEM. Dry samples on a silicon surface were sputter-coated with gold before measurement. Fluorescent images of cells were obtained with either Zeiss Axio Observer.Z1 fluorescence microscope or Leica TCS SP MP Inverted Confocal Microscope. Cellular fluorescent intensity distribution was determined with Becton Dickinson FACScan Analytic Flow Cytometer. A 488 nm argon laser was used as the excitation light.