BLES + 30 mol% d7-chol

1. ToF-SIMS negative ion images of two BLES (bovine lipid extract surfactant) LB films containing 0 mol% (A, C) and 30 mol% (B, D) cholesterol-d7. M255 corresponds to the palmitate group, M2 to deuterium present in the tail of cholesterol-d7. Images E, F, G, H were obtained by subjecting A, B, C, D, respectively to a smoothing function available as part of the IonTof software, and show more clearly the location of the palmitate group and deuterium. Images are 50 x 50 mm2, 256 x 256 pixels with 1 shot/pixel. BLES + 30 mol% d7-chol BLES A B M255 D C M2 F E M255 processed G H M2 processed This set of images is published in the Biophysical Journal.  The goal of that work was to determine the function of cholesterol in an animal extracted surfactant (BLES).  TOF-SIMS was used to determine the location of cholesterol in an LB-film of BLES. Courtesy of Eleonora Keating, Univ. of Western Ontario

2. Positive ion TOF-SIMS images of a 50:30:20 d4-DPPC:POPC:d31-POPG LB film deposited on gold –coated mica at p = 30 mN/m. Mass 50 corresponds to C3D7 which is specific to d31-POPG, masses 104 and 184 correspond to choline and phosphocholine which are specific to POPC respectively, masses 108 and 188 correspond to d4-choline and d4-phosphocholine specific to d4-DPPC and mass 739 corresponds to d4-DPPC-H+. These images show that POPC and d31-POPG are present in the LE phase while d4-DPPC is highly concentrated in the LC phase. Images are 50 x 50 mm2, 256 x 256 pixels with 1 shot/pixel. This set of images shows that TOF-SIMS can be used to determine the location of each phospholipid in an LB film of a mixture.  In this work the authors are trying to design a synthetic surfactant that will eventually replace animal extracted BLES which is currently administered to premature babies throughout Canada. Courtesy of Eleonora Keating, Univ. of Western Ontario