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Chan VWY, Phan CM, Ngo W, Jones L. Lysozyme Deposition on Contact Lenses in an In Vitro Blink-Simulation Eye Model Versus a Static Vial Deposition Model. Eye Contact Lens 2021; 47:388-393. [PMID: 33840748 DOI: 10.1097/icl.0000000000000784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/07/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate active lysozyme deposition on daily disposable (DD) contact lenses (CL) using a novel in vitro blink model. METHODS Three conventional hydrogel DD CL materials (etafilcon A, omafilcon A, nelfilcon A) and three silicone hydrogel DD CL materials (delefilcon A, senofilcon A, somofilcon A) were tested. The device blink rate was set to 6 blinks/min with a tear flow rate of 1 μL/min using an artificial tear solution (ATS) containing lysozyme and other typical tear film components. After incubation at 2, 4, or 8 hr, lenses were removed, and lysozyme activity was measured. A separate experiment was conducted with lenses incubated in a static vial containing 480 μL of ATS. RESULTS Etafilcon A deposited significantly higher amounts of active lysozyme (402±102 μg/lens) than other lens materials after 8 hr (P<0.0001). Etafilcon A had a higher amount of active lysozyme using the blink model compared with the static vial (P=0.0435), whereas somofilcon A (P=0.0076) and senofilcon A (P=0.0019) had a higher amount of lysozyme activity in the vial compared with the blink model. CONCLUSION The blink model can be tuned to provide quantitative data that closely mimics ex vivo studies and can be used to model deposition of lysozyme on CL materials.
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Affiliation(s)
- Vivian W Y Chan
- Centre for Ocular Research and Education (CORE) (V.W.Y.C., C.-M.P., W.N., L.J.), School of Optometry and Vision Science, University of Waterloo, Waterloo, ON, Canada ; and Centre for Eye and Vision Research (CEVR) (C.-M.P., W.N., L.J.), Hong Kong, China
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Heynen M, Ng A, Martell E, Subbaraman LN, Jones L. Activity of Deposited Lysozyme on Contemporary Soft Contact Lenses Exposed to Differing Lens Care Systems. Clin Ophthalmol 2021; 15:1727-1733. [PMID: 33935489 PMCID: PMC8079347 DOI: 10.2147/opth.s296116] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 03/17/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose The amount of protein deposition on soft contact lenses and to what extent the proteins are denatured may have an impact on comfortable wearing times of contact lenses. The purpose of this study was to evaluate the effects of two lens care systems on total protein and the quantity and activity of lysozyme deposited on worn senofilcon A, silicone hydrogel contact lenses. Participants and Methods Thirty symptomatic soft contact lens wearers were enrolled into a 4-week prospective, randomized, bilateral eye, daily-wear, crossover, double-masked study. Participants were fitted with biweekly senofilcon A lenses and were assigned either a polyquaternium-1 and myristamidopropyl dimethylamine-containing system (OPTI-FREE RepleniSH) or a peroxide-based system (CLEAR CARE). After each wear period, proteins were extracted from the lenses and analyzed for total protein, total lysozyme quantity and activity. Results The use of either the peroxide-based system or the polyquaternium-1 and myristamidopropyl dimethylamine-containing system resulted in no difference (P>0.05) to the amount of total protein deposited on the lenses (6.7 ± 2.8 micrograms/lens versus 7.3 ± 2.8 micrograms/lens, respectively) or to the amount of denatured lysozyme deposits (0.8 ± 0.7 versus 0.9 ± 0.7 micrograms/lens), respectively. The total amount of lysozyme deposited on the lenses was significantly lower when using the peroxide-based system (1.3 ± 0.9 micrograms/lens) compared to the polyquaternium-1 and myristamidopropyl dimethylamine-containing system (1.7 ± 1.0 micrograms/lens) (P=0.02). Conclusion The inactivation of lysozyme deposited on senofilcon A lenses when disinfected with the peroxide-based or the polyquaternium-1 and myristamidopropyl dimethylamine-containing systems were neither statistically nor clinically significant and the overall amounts of denatured lysozyme recovered from the lenses were low (<1 microgram/lens).
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Affiliation(s)
- Miriam Heynen
- Centre for Ocular Research and Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Alan Ng
- Centre for Ocular Research and Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Elizabeth Martell
- Centre for Ocular Research and Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Lakshman N Subbaraman
- Centre for Ocular Research and Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada
| | - Lyndon Jones
- Centre for Ocular Research and Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Ontario, Canada.,Centre for Eye and Vision Research (CEVR), Hong Kong Science Park, Hong Kong
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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, 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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Mikhail AS, Ranger JJ, Liu L, Longenecker R, Thompson DB, Sheardown HD, Brook MA. Rapid and Efficient Assembly of Functional Silicone Surfaces Protected by PEG: Cell Adhesion to Peptide-Modified PDMS. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 21:821-42. [DOI: 10.1163/156856209x445311] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Andrew S. Mikhail
- a Department of Chemical Engineering, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4L7
| | - Jill J. Ranger
- b Department of Chemistry, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4M1
| | - Lihua Liu
- c Department of Chemistry, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4M1
| | - Ryan Longenecker
- d Department of Chemistry, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4M1
| | - David B. Thompson
- e Department of Chemistry, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4M1
| | - Heather D. Sheardown
- f Department of Chemical Engineering, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4L7
| | - Michael A. Brook
- g Department of Chemistry, McMaster University, 1280 Main St. W., Hamilton, ON, Canada L8S 4M1.
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Subbaraman LN, Jones L. Kinetics of Lysozyme Activity Recovered from Conventional and Silicone Hydrogel Contact Lens Materials. JOURNAL OF BIOMATERIALS SCIENCE-POLYMER EDITION 2012; 21:343-58. [DOI: 10.1163/156856209x415873] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Affiliation(s)
- Lakshman N. Subbaraman
- a Centre for Contact Lens Research, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
| | - Lyndon Jones
- b Centre for Contact Lens Research, School of Optometry, University of Waterloo, 200 University Avenue West, Waterloo, ON N2L 3G1, Canada
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Protein deposition on contact lenses: The past, the present, and the future. Cont Lens Anterior Eye 2012; 35:53-64. [DOI: 10.1016/j.clae.2011.12.005] [Citation(s) in RCA: 119] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2010] [Revised: 12/18/2011] [Accepted: 12/24/2011] [Indexed: 11/19/2022]
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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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Ex Vivo Protein Deposition on Bi-Weekly Silicone Hydrogel Contact Lenses. Optom Vis Sci 2010. [DOI: 10.1097/opx.0b013e3181ce0681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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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