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Uptake and Release of Polyvinyl Alcohol from Hydrogel Daily Disposable Contact Lenses. Optom Vis Sci 2019; 96:180-186. [DOI: 10.1097/opx.0000000000001351] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Omali NB, Subbaraman LN, Heynen M, Ng A, Coles-Brennan C, Fadli Z, Jones L. Surface versus bulk activity of lysozyme deposited on hydrogel contact lens materials in vitro. Cont Lens Anterior Eye 2018; 41:329-334. [DOI: 10.1016/j.clae.2018.03.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2017] [Revised: 12/15/2017] [Accepted: 03/18/2018] [Indexed: 01/12/2023]
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A Review of Techniques to Measure Protein Sorption to Soft Contact Lenses. Eye Contact Lens 2017; 43:276-286. [PMID: 28198731 DOI: 10.1097/icl.0000000000000366] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To compare and critically evaluate a variety of techniques to measure the quantity and biological activity of protein sorption to contact lenses over short time periods. METHODS A literature review was undertaken investigating the major techniques to measure protein sorption to soft contact lens materials, with specific reference to measuring protein directly on lenses using in situ, ex situ, protein structural, and biological activity techniques. RESULTS The use of in situ techniques to measure protein quantity provides excellent sensitivity, but many are not directly applicable to contact lenses. Many ex situ techniques struggle to measure all sorbed proteins, and these measurements can have significant signal interference from the lens materials themselves. Techniques measuring the secondary and tertiary structures of sorbed proteins have exhibited only limited success. CONCLUSIONS There are a wide variety of techniques to measure both the amount of protein and the biological activity of protein sorbed to soft contact lens materials. To measure the mass of protein sorbed to soft contact lenses (not just thin films) over short time periods, the method of choice should be I radiolabeling. This technique is sensitive enough to measure small amounts of deposited protein, provided steps are taken to limit and measure any interaction of the iodine tracer with the materials. To measure the protein activity over short time periods, the method of choice should be to measure the biological function of sorbed proteins. This may require new methods or adaptations of existing ones.
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Hall B, Heynen M, Jones LW, Forrest JA. Analysis of Using I125Radiolabeling for Quantifying Protein on Contact Lenses. Curr Eye Res 2015; 41:456-65. [DOI: 10.3109/02713683.2015.1031350] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Hall B, Jones L, Forrest JA. Kinetics of Competitive Adsorption between Lysozyme and Lactoferrin on Silicone Hydrogel Contact Lenses and the Effect on Lysozyme Activity. Curr Eye Res 2014; 40:622-31. [PMID: 25251834 DOI: 10.3109/02713683.2014.946518] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE 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.
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Affiliation(s)
- Brad Hall
- Centre for Contact Lens Research, School of Optometry and Vision Science , Waterloo, Ontario , Canada and
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Hall B, Phan CM, Subbaraman L, Jones LW, Forrest J. Extraction versus In Situ Techniques for Measuring Surface-Adsorbed Lysozyme. Optom Vis Sci 2014; 91:1062-70. [DOI: 10.1097/opx.0000000000000354] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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Ng A, Heynen M, Luensmann D, Subbaraman LN, Jones L. Impact of tear film components on the conformational state of lysozyme deposited on contact lenses. J Biomed Mater Res B Appl Biomater 2013; 101:1172-81. [PMID: 23564739 DOI: 10.1002/jbm.b.32927] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2012] [Revised: 12/06/2012] [Accepted: 01/30/2013] [Indexed: 11/07/2022]
Affiliation(s)
- Alan Ng
- Centre for Contact Lens Research; School of Optometry and Vision Science; University of Waterloo; 200 University Avenue West Waterloo Ontario N2L 3G1 Canada
| | - Miriam Heynen
- Centre for Contact Lens Research; School of Optometry and Vision Science; University of Waterloo; 200 University Avenue West Waterloo Ontario N2L 3G1 Canada
| | - Doerte Luensmann
- Centre for Contact Lens Research; School of Optometry and Vision Science; University of Waterloo; 200 University Avenue West Waterloo Ontario N2L 3G1 Canada
| | - Lakshman N. Subbaraman
- Centre for Contact Lens Research; School of Optometry and Vision Science; University of Waterloo; 200 University Avenue West Waterloo Ontario N2L 3G1 Canada
| | - Lyndon Jones
- Centre for Contact Lens Research; School of Optometry and Vision Science; University of Waterloo; 200 University Avenue West Waterloo Ontario N2L 3G1 Canada
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Ng A, Heynen M, Luensmann D, Subbaraman LN, Jones L. Optimization of a fluorescence-based lysozyme activity assay for contact lens studies. Curr Eye Res 2013; 38:252-9. [PMID: 23373676 DOI: 10.3109/02713683.2012.757324] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE To optimize a fluorescence-based lysozyme activity assay to investigate the conformational state of lysozyme in solution and to determine the impact of extraction and evaporation procedures and the possible interference of contact lens materials on lysozyme activity. METHODS The fluorescence-based lysozyme activity assay, Enzchek (Molecular Probes Inc, Eugene, OR) which utilizes fluorescently quenched Micrococcus lysodeikticus, was compared to the gold standard, classical lysozyme turbidity assay, using four differently concentrated lysozyme samples (20, 10, 5.0 and 2.0 ng/µL). Furthermore, six differently concentrated lysozyme samples (2.0, 1.0, 0.5, 0.25, 0.125 and 0.01 µg/µL) were quantified using the fluorescence-based assay in the presence of extraction solvents consisting of 0.2% and 0.02% trifluroacetic acid/acetonitrile and following evaporation procedures. RESULTS A standard curve was generated by the fluorescence-based assay ranging from 2 to 150 ng. The total active lysozyme quantified in the four lysozyme samples was not significantly different between the two assays (p > 0.05) and the concordance correlation coefficient was determined to be 0.995. However an average discrepancy between the two assays was found to be 0.474 ng, with the turbidity assay typically reporting higher active lysozyme measurements. The sensitivity of the fluorescence-based assay was higher than the classical turbidity assay when quantifying 20 ng or less active lysozyme. Following the extraction and evaporation procedures and the addition of lens extracts, the total active lysozyme recovered was 95% or greater. CONCLUSIONS In comparison to the classical turbidity assay, the fluorescence-based assay is a very sensitive method, making it a favorable technique, particularly when studying contact lens materials that deposit relatively low levels of lysozyme.
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Affiliation(s)
- Alan Ng
- Centre for Contact Lens Research, School of Optometry and Vision Science, University of Waterloo, Waterloo, ON, Canada.
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Hall B, Jones L, Forrest JA. Measuring the kinetics and activity of adsorbed proteins:In vitrolysozyme deposited onto hydrogel contact lenses over short time periods. J Biomed Mater Res A 2012; 101:755-64. [DOI: 10.1002/jbm.a.34357] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2011] [Revised: 06/05/2012] [Accepted: 06/20/2012] [Indexed: 11/11/2022]
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Weeks A, Subbaraman LN, Jones L, Sheardown H. The Competing Effects of Hyaluronic and Methacrylic Acid in Model Contact Lenses. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 23:1021-38. [DOI: 10.1163/092050611x569060] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Andrea Weeks
- a School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada L8S 4L7
| | | | - Lyndon Jones
- c School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada L8S 4L7; Department of Chemical Engineering, McMaster University, Hamilton, ON, Canada L8S 4L7; Centre for Contact Lens Research, University of Waterloo, Waterloo, ON, Canada
| | - Heather Sheardown
- d School of Biomedical Engineering, McMaster University, Hamilton, ON, Canada L8S 4L7; Department of Chemical Engineering, McMaster University, Hamilton, ON, Canada L8S 4L7; Centre for Contact Lens Research, University of Waterloo, Waterloo, ON, Canada.
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Chow LM, Subbaraman LN, Sheardown H, Jones L. Kinetics of in Vitro Lactoferrin Deposition on Silicone Hydrogel and FDA Group II and Group IV Hydrogel Contact Lens Materials. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 20:71-82. [PMID: 19105901 DOI: 10.1163/156856208x393509] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Lisa M. Chow
- a Centre for Contact Lens Research, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
| | - Lakshman N. Subbaraman
- b Centre for Contact Lens Research, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
| | - Heather Sheardown
- c Department of Chemical Engineering, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4L8
| | - Lyndon Jones
- d Centre for Contact Lens Research, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, Ontario, Canada N2L 3G1
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Abstract
PURPOSE To determine the efficiency of several protein extraction or precipitation treatments used in proteomic analyses. METHODS Tear samples were taken from each eye of 40 normal subjects using glass microcapillaries. Tear volume was measured followed by storage at -86°C. Lotrafilcon B contact lenses were fitted and worn for 14 days, followed by removal and storage at -86°C. Tear samples from each eye within a subject were randomly assigned to either one of four chemical treatments (acetone, trichloroacetic acid, urea, and trifluoroacetic acid/acetonitrile [TFA/ACN]) or no chemical treatment in groups of 10. Contact lens samples were subjected to the same treatments as tear samples for each subject, with a second treatment preceding the first. Protein concentrations were quantified by Bradford assay. RESULTS For tear samples, a significant reduction in total protein was observed when subjected to any of the four treatments studied compared with those samples left untreated. A positive relationship was noted between protein concentration and tear volume for treated, untreated, and combined tear samples. For contact lens samples, there was a significant reduction in the amount of deposited protein removed when comparing acetone, trichloroacetic acid, and urea with TFA/ACN. A second extraction from contact lenses assigned to the urea and TFA/ACN groups yielded a significant amount of additional protein compared with the amount removed initially. CONCLUSIONS Tear samples subjected to any of the evaluated chemical treatments provided significantly less protein than untreated samples. For contact lenses, TFA/ACN extraction provided the highest yield of available protein out of the four treatments evaluated.
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Glasier MA, Subbaraman LN, Senchyna M, Jones L. A Solid-Phase Assay for the Quantitation of Total Protein Eluted from Balafilcon, Lotrafilcon, and Etafilcon Contact Lenses. Curr Eye Res 2009; 33:631-40. [DOI: 10.1080/02713680802291537] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Affiliation(s)
- Mary-Ann Glasier
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada
| | - Lakshman N. Subbaraman
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada
| | | | - Lyndon Jones
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada
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Care Regimen and Lens Material Influence on Silicone Hydrogel Contact Lens Deposition. Optom Vis Sci 2009; 86:251-9. [DOI: 10.1097/opx.0b013e318196a74b] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Efficacy of an Extraction Solvent Used to Quantify Albumin Deposition on Hydrogel Contact Lens Materials. Eye Contact Lens 2009; 35:76-80. [DOI: 10.1097/icl.0b013e318199aff6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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