title: Does lung surfactant promote disaggregation of nanostructured titanium dioxide?
abstract: OBJECTIVE
  Nanostructured titanium dioxide (TiO2) is highly aggregated and agglomerated when inhaled. There are discussions regarding whether lung surfactant may promote the disaggregation of TiO2 particles. We investigated whether dipalmitoyl phosphatidyl-choline (DPPC), the main component of lung surfactant, can split the bonds between TiO2 aggregates and agglomerates.
  
  
  METHODS
  We calculated the energy required to split aggregates into primary particles and agglomerates into aggregates as well the energy of the interaction of a TiO2 surface with a DPPC bilayer. To test the calculations, we measured the particle size distribution of TiO2 suspensions in a pulmonary liquid model.
  
  
  RESULTS
  Calculated splitting energy between TiO2 aggregates was 1 J/m2 and 10 J/m2 between primary particles. The calculated interaction between DPPC and TiO2 was significantly weaker (0.05 J/m2). Calculations were shown to be in accordance with the measured particle size distribution of TiO2 suspensions in the pulmonary liquid model.
  
  
  CONCLUSIONS
  We conclude that lung surfactant does not promote the disaggregation of TiO2 agglomerates and aggregates.
authors.affiliation: Aerosil&Silanes, Degussa AG, Hanau, Germany. monika.maier@degussa.com
authors.forename: Monika
authors.initials: M
authors.lastname: Maier
authors.forename: Bernd
authors.initials: B
authors.lastname: Hannebauer
authors.forename: Henning
authors.initials: H
authors.lastname: Holldorff
authors.forename: Peter
authors.initials: P
authors.lastname: Albers
mesh_terms: D015060:1,2-Dipalmitoylphosphatidylcholine / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000737:chemistry*; D010316:Particle Size; D011663:Pulmonary Surfactants / Q000737:chemistry*; D013535:Suspensions / Q000737:chemistry; D014025:Titanium / Q000737:chemistry*
chemical_list: D004396:Coloring Agents; D011663:Pulmonary Surfactants; D013535:Suspensions; C009495:titanium dioxide; D015060:1,2-Dipalmitoylphosphatidylcholine; D014025:Titanium