Abstract
Purpose: :
Proteins within tears, including lactoferrin, accumulate on and within contact lenses during wear. The presence of denatured protein deposits can result in reduced vision, discomfort and clinical complications for the contact lens wearer. Furthermore, beneficial aspects of tear proteins, such as antimicrobial activity, may be lost when tear proteins denature. This in vitro study investigates the ability of a novel multi-purpose solution (MPS) to maintain the functional and structural integrity of human lactoferrin.
Methods: :
Human lactoferrin, formulated in either phosphate buffered saline or an artificial tear solution, was mixed with the novel MPS and challenged with the denaturant, sodium dodecyl sulphate (SDS). The structural integrity of lactoferrin was assessed using differential scanning calorimetry (DSC) and native polyacrylamide gel electrophoresis (PAGE). In addition, the functional integrity of lactoferrin was investigated by adding the test solution to a suspension of either Pseudomonas aeruginosa (ATCC 9027) or Staphylococcus aureus (ATCC 6538), and assessing the turbidity of the solution.
Results: :
The novel MPS reversed the loss of the denaturation peak detected in the SDS-treated lactoferrin sample during DSC analysis. The novel MPS also reversed the shift in the position of the denatured lactoferrin band detected on the native gels during PAGE. Furthermore, the high levels of turbidity detected in the bacterial suspensions exposed to SDS-treated lactoferrin, were reduced when the lactoferrin was exposed to the novel MPS prior to SDS treatment.
Conclusions: :
These data suggest that the novel MPS maintained the structural and functional integrity of human lactoferrin, following SDS exposure. Additional work in the area should be performed to advance the understanding of protein management.
Keywords: protein structure/function • contact lens