Saxsess camera

SAXS measurements were performed using a SAXSess camera (Anton Parr, Austria) attached to a PW3830 X-ray generator (PANalytical, The Netherlands) , which was operated at 40 kV and 50 mA, with a sealed-tube anode (Cu-Kα wavelength of 0.154 nm) . The measurements were carried out at room temperature. Two-dimensional scattering patterns recorded on an image plate detector were read out by a Cyclone system (Perkin-Elmer, Downers Grove, IL, USA) and were converted into one-dimensional curves as a function of the scattering vector, q＝ (4π/λ ) sin (θ /2) , where θ is the total scattering angle, with SAXSQuant software (Anton Paar) . All scattering intensities were transmission calibrated by adjusting the attenuated primary intensity at q＝0 to unity and corrected for the background scattering of the sample cell and solvent. The SAXS peak ratio was used to confirm the type of the lyotropic liquid crystals.

DSC measurements were performed using a Mettler Toledo DSC 1 (Mettler Toledo, Greifensee, Switzerland) operating with STAR e software under nitrogen atmosphere. The sample weight was adjusted to 5 mg, and samples were placed in an aluminum pan, and then heated from 0 to 80℃ with a heating rate of 3℃/min.
2.4 Small Angle X-ray Scattering (SAXS) and Wide Angle X-ray Scattering (WAXS) SAXS and WAXS measurements (SWAXS measurements) were performed with a SAXSess camera (Anton Paar, Graz, Austria) . Cu-Kα (λ : 1.542 Å) radiation was used. The scattering intensity from each sample was measured at 25℃ for 10 min with a cyclone imaging plate detection system (Perkin-Elmer, Waltham, MA, USA) and the results were analyzed using SAXSQuant software (Anton Paar) .

Scattering experiments were carried out using a W 3830 X-ray generator (PANalytical Co., Ltd., Almedo, Netherlands) and diffraction patterns were recorded using a SAXSess camera (Anton Paar Co., Ltd., Graz, Australia) in a line collimation system. A semitransparent beam stop was available to attenuate the beam. The samples were placed in a vacuum-proof metallic cell between Mylar windows, and the cell was tightened at both ends. Each sample was exposed to radiation of λ＝0.154 nm for 20 minutes in a vacuum, and the scattering pattern was detected on a 2D imaging plate. A cyclone reader (PerkinElmer Inc., Massachusetts, USA) was used to read the scattering patterns, which were converted to 1D profiles using SAXSquant software (Anton Paar Co., Ltd.) . All data were normalized to the same incident primary beam intensity 18, 23) .

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) .