Development of an enzymatic method for the evaluation of protein deposition on contact lenses

Abstract

The aim of this study was to evaluate a new digestion method to quantify protein deposition on contact lenses. Four silicone hydrogel and one hydrogel contact lens material were incubated in lactoferrin, lysozyme, immunoglobulin A, and bovine serum albumin solutions at approximate physiological concentrations and temperature. Immobilized trypsin was used to digest the protein deposits from the contact lens surfaces. The total protein absorbed to lenses was extracted and digested using sequencing grade trypsin. The tryptic peptides were quantified using selected reaction monitoring mass spectrometry. The concentration of surface protein deposits was either lower than or the same as the total protein for all lens types and proteins. Immobilised trypsin can digest protein deposits from the surface of contact lenses. This ability to analyse the amount of protein at a contact lens surface may help in elucidating the effect of surface deposition on clinical outcomes during lens wear.

Keywords:

• Contact lens
• protein
• deposition
• mass spectrometry
• confocal microscopy

Acknowledgements

This study was supported by Alcon laboratories (Australia) Pty Ltd. The authors would like to thank Dr Nancy Briggs for statistical advice. Over the past five years, Mark Willcox and his research group at the School of Optometry and Vision Science, UNSW have received research funding and/or honoraria from one or more of the following companies: Alcon, Allergan, CooperVision, Johnson & Johnson Vision Care, Inc., Menicon, and the Ophtecs Corporation.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The author(s) reported there is no funding associated with the work featured in this article.