title: Kinetics of Competitive Adsorption between Lysozyme and Lactoferrin on Silicone Hydrogel Contact Lenses and the Effect on Lysozyme Activity.
abstract: OBJECTIVE
  To determine the effect of competitive adsorption between lysozyme and lactoferrin on silicone hydrogel contact lenses and the effect on lysozyme activity.
  
  
  METHODS
  Three commercially available silicone hydrogel contact lens materials (senofilcon A, lotrafilcon B and balafilcon A) were examined, for time points ranging from 10 s to 2 h. Total protein deposition was determined by I(125) radiolabeling of lysozyme and lactoferrin, while the activity of lysozyme was determined by a micrococcal activity assay.
  
  
  RESULTS
  Senofilcon A and balafilcon A did not show any relevant competitive adsorption between lysozyme and lactoferrin. Lotrafilcon B showed reduced protein deposition due to competitive adsorption for lactoferrin at all time points and lysozyme after 7.5 min. Co-adsorption of lactoferrin and lysozyme decreased the activity of lysozyme in solution for senofilcon A and lotrafilcon B, but co-adsorption had no effect on the surface activity of lysozyme for all lens types investigated.
  
  
  CONCLUSIONS
  Competition between lysozyme and lactoferrin is material specific. Co-adsorption of lysozyme and lactoferrin does not affect the activity of surface-bound lysozyme but can reduce the activity of subsequently desorbed lysozyme.
authors.affiliation: Centre for Contact Lens Research, School of Optometry and Vision Science , Waterloo, Ontario , Canada and.
authors.forename: Brad
authors.initials: B
authors.lastname: Hall
authors.forename: Lyndon
authors.initials: L
authors.lastname: Jones
authors.forename: James A
authors.initials: JA
authors.lastname: Forrest
mesh_terms: D000327:Adsorption; D003263:Contact Lenses, Hydrophilic; D006801:Humans; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry* / Q000378:metabolism*; D007781:Lactoferrin / Q000378:metabolism*; D009113:Muramidase / Q000378:metabolism*; D012828:Silicones / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D012828:Silicones; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D009113:Muramidase; D007781:Lactoferrin
keywords: Competitive protein adsorption; contact lens; lysozyme activity; protein deposition; silicone hydrogel