lactoferrin and hydroxyethyl-methacrylate

Investigations of polymer interactions in single protein solutions is a necessary step in the elucidation of in vivo early binding events during protein deposition on hydroxyethyl methacrylate-based contact lens materials. Quantity and tenacity of binding of significant tear components to groups I and IV contact lenses was assessed. Competitive binding by these components was also examined.. Adsorption on FDA groups I and IV hydrogel lenses was monitored using I-labeled protein. Lenses were incubated in increasing concentrations of radiolabeled single species proteins in solution. For competition experiments, concentration of each radiolabeled protein was held constant and the adsorption/sorption challenged with increasing concentrations of nonlabeled proteins. Lenses were soaked in phosphate-buffered saline to determine desorption.. Group IV lenses bound large amounts of lysozyme, whereas group I lenses bound highest amounts of albumin. Albumin binding to both lens types was relatively strong and could not be competed from binding by other proteins lysozyme, lactoferrin, and mucin. Mucin at high concentrations tended to positively cooperate with the binding of lactoferrin and albumin to all lenses.. Binding of proteins to hydroxyethyl methacrylate-based hydrogel lens surfaces is affected by charge and polymer components, and perhaps manufacturing processes. Albumin binds strongly to lens surfaces, and this may play an adverse role during contact lens wear.

Topics: Adsorption; Albumins; Binding, Competitive; Contact Lenses, Hydrophilic; Eye Proteins; Humans; In Vitro Techniques; Lactoferrin; Methacrylates; Mucins; Muramidase; Osmolar Concentration; Temperature; Time Factors

The purpose of the present study was to determine the whether contact lens wear disturbed the levels of tear proteins and to further determine whether this was a transient or continuous disruption.. Lactoferrin, lysozyme and albumin were quantitated from tears of neophyte patients and were compared with the levels of these proteins in contact lens wearers after one and six nights and 6 months of extended wear. The quantitation of these tear proteins was performed by sandwich ELISA and turbidimetric assay.. Results showed that there were no statistically significant changes in the concentration of any of the proteins investigated.. Extended wear of hydrogel lenses does not appear to alter the concentration of the major tear film proteins, indicating that the tear film is constantly replenished to maintain protein levels, which are depleted due to protein adsorption to the lens surface.

Topics: Albumins; Blotting, Western; Contact Lenses, Extended-Wear; Electrophoresis, Polyacrylamide Gel; Enzyme-Linked Immunosorbent Assay; Eye Proteins; Follow-Up Studies; Humans; Lactoferrin; Methacrylates; Muramidase; Tears