Tcs 120

We performed small angle X-ray scattering (SAXS) ex-Fig. 1 Strategy of inferring pH sensitivity of the anionic liposomes at acidic pH.
periments on the pH-sensitive liposomes to examine their static structures using a SAXSess camera (Anton-Paar, Graz, Austria) . A PW3830 sealed-tube anode X-ray generator (GE Inspection Technologies, Germany) was operated at 40 kV and 50 mA. A monochromatic, line-shaped primary X-ray beam of Cu-K α radiation (λ＝0.1542 nm) was provided by focusing multilayer optics and a block collimator. The sample temperature was controlled with a thermostated sample holder unit (TCS 120, Anton-Paar) . Two-dimensional (2D) scattering patterns were recorded by an imaging plate (IP) detector (Perkin Elmer, USA) . By integrating the 2D profiles, one-dimensional (1D) scattering intensities were obtained as a function of the magnitude of the scattering vector q＝ (4π/λ) sin (θ /2) , where θ is the total scattering angle. A semi-transparent beam stop enabled us to monitor an attenuated primary beam at q＝0. All measured intensities were calibrated for transmission by normalizing a zero-q primary intensity to unity. The background scattering contributions from the capillary and solvent were corrected. Absolute intensity calibration was performed using water as a secondary standard 18) .