COLL 374 |
| H. William Taeusch1, Jorge Bernardino de la Serna2, Coralie Alonso3, Jesus Perez-Gil2, and Joseph A. Zasadzinski4. (1) Pediatrics, University of California, San Francisco, CA 94143, (2) Bioquimica y Biologia Molecular Biologia Molecular, Universidad Complutense, Madrid, Spain, (3) Department of Chemical Engineering, University of California Santa Barbara, Engineering II, Santa Barbara, CA 93106, (4) Department of Chemical Engineering, University of California, Santa Barbara, CA 93106 |
| Spreading assays provide a quick and reproducible way of differentiating activity of surfactants with and without inhibition (Diemel, Crit Care Med, 2002)]. One aqueous drop (7ul) of native porcine surfactant, surfactant extract, Curosurf, Infasurf, or Survanta (105 ug) was placed on subphase surface. Surface pressures were measured in either a NIMA or Kibron surface balance. Surface pressures rose to ca. 43 mN/m in less than 25 sec, however little (< 5 mN/m) change in surface pressure after application of surfactant occurred when serum protein was present in the subphase. Higher concentrations of subphase protein (100-350 ug/ml)were required for inhibition to occur at 37C vs 24 C (50-150 ug/ml). Surfactants spread in organic solvent were not inhibited by subphase serum. After inclusion of either polyethylene glycol (10 kDa; 5% w/v) or hyaluronic acid (1024 kDa; 0.125%) in subphase with serum, surface pressure vs time plots resembled those without serum in subphase. Different surfactants showed different susceptibilities to inhibition with serum and although native porcine surfactant was inactivated only with the highest concentrations of serum, it too had improved surface activity in the presence of subphase polymer. After application of surfactants, Brewster angle microscopy revealed evidence of both subphase and surface lateral spread and subphase to surface transfer ("raindrops") that were inhibited by subphase serum. We conclude that subphase serum inhibits movement of surfactant to the surface in ways that may play a role in various acute lung injuries. Subphase polymers that are present in normal pulmonary subphase may be important additives in treating lung diseases with surfactant. |
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Surface and Colloid Chemistry Award Symposium Honoring Joseph Zasadzinski
8:10 AM-12:10 PM, Wednesday, March 31, 2004 Marriott -- Orange County 3, Oral
Division of Colloid and Surface Chemistry |