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Scheuer C, Barniak VL, Phatak NR, Rah MJ, Reindel W. Effect of Contact Lens Solutions in Stabilizing the Activity of Tear Lysozyme [Response to Letter]. CLINICAL OPTOMETRY 2024; 16:81-82. [PMID: 38444786 PMCID: PMC10913791 DOI: 10.2147/opto.s463864] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 02/12/2024] [Accepted: 02/26/2024] [Indexed: 03/07/2024]
Affiliation(s)
| | | | | | - Marjorie J Rah
- Vision Care, Bausch & Lomb Incorporated, Rochester, NY, USA
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Scheuer CA, Barniak VL, Phatak NR, Rah MJ, Reindel W. Effect of Contact Lens Solutions in Stabilizing the Activity of Tear Lysozyme. CLINICAL OPTOMETRY 2023; 15:119-127. [PMID: 37205004 PMCID: PMC10187650 DOI: 10.2147/opto.s404261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 04/17/2023] [Indexed: 05/21/2023]
Abstract
Purpose Interactions between tear proteins and the interfaces of contact lenses can be complex and can influence contact lens wear success. Tear proteins, including lysozyme, function to maintain the balance of ocular surface homeostasis, as evidenced by the effects of its conformation relative to stabilizing the tear film and its potential impact on corneal epithelial cells. Contact lens manufacturers include components in lens care and blister package solutions to help stabilize the tear film and preserve homeostasis. This in vitro study was performed to evaluate the ability of daily disposable contact lens package solutions to stabilize lysozyme and preserve its native conformation under denaturing conditions. Methods Lysozyme was added to contact lens solutions sampled from kalifilcon A, etafilcon A, senofilcon A, narafilcon A, nelfilcon A, verofilcon A, delefilcon A, somofilcon A, and stenfilcon A blister packages, then mixed with the protein denaturant sodium lauryl sulfate. Lysozyme activity was evaluated by adding test solutions to a suspension of Micrococcus luteus. Native lysozyme lyses the Micrococcus luteus cell wall, which decreases suspension turbidity. Stabilization of lysozyme activity was determined by comparing suspension turbidity before and after exposure to test solutions. Results Lysozyme stabilization was 90.7% for kalifilcon A solution, a statistically significant improvement (p < 0.05) compared to phosphate buffered saline (PBS, negative control). No significant improvement was observed with any other contact lens solution (all lysozyme stabilization < 5.00%). Conclusion The representative tear protein lysozyme was significantly more stable in the novel kalifilcon A contact lens solution containing multiple moisturizers and osmoprotectants than in PBS or other daily disposable contact lens solutions. The lysozyme activity assay provides mechanistic evidence that the kalifilcon A contact lens solution can stabilize proteins under conditions that typically denature proteins, which may contribute to maintaining ocular surface homeostasis.
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Affiliation(s)
| | | | - Nitasha R Phatak
- Vision Care, Bausch & Lomb Inc., Rochester, NY, USA
- Correspondence: Nitasha R Phatak, Vision Care, Bausch & Lomb Incorporated, Rochester, NY, USA, Tel +1 585 413-6397, Email
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Contact Lens Wear Induces Alterations of Lactoferrin Functionality in Human Tears. Pharmaceutics 2022; 14:pharmaceutics14102188. [PMID: 36297623 PMCID: PMC9612143 DOI: 10.3390/pharmaceutics14102188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Revised: 10/10/2022] [Accepted: 10/12/2022] [Indexed: 11/06/2022] Open
Abstract
The tear film is a complex matrix composed of several molecular classes, from small metal ions to macromolecules. Contact lens (CL) wear can affect the protein homeostasis of the tear film, by accumulating deposits on the CL surface and/or altering their structural and functional properties. This work investigates the effect of CL wear on lactoferrin (Lf), one of the most abundant tear proteins, known as an unspecific biomarker of inflammation. Tears from eight volunteers were collected and analyzed after alternated periods of CL wear and without CL. The experimental approach is to probe Lf into unprocessed human tears by the peculiar fluorescence emission originating from complex formation of Lf with terbium (Tb3+) at the iron-binding sites. The experimental data indicate that CL wear does not significantly affect the total amount of Lf. On the other hand, Lf affinity for Tb3+ is reduced upon CL wear, suggesting relevant changes in Lf structure and possible alterations of protein functionality. Future studies based on this approach will help define CL features (material, lens-care solution, wearing time, etc.) with minimal effects on tear protein activity, in order to obtain more biocompatible and comfortable devices.
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Chang WH, Liu PY, Lin DE, Jiang YT, Lu CJ, Hsu YHH. Dynamic Protein Adsorption-Desorption Analysis of Contact Lenses in a Three-Dimensional-Printed Eye Model. Macromol Res 2022. [DOI: 10.1007/s13233-022-0003-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Masoudi S, Willcox M. Development of an enzymatic method for the evaluation of protein deposition on contact lenses. BIOFOULING 2022; 38:84-99. [PMID: 35016572 DOI: 10.1080/08927014.2021.2019225] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 06/14/2023]
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.
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Affiliation(s)
- Simin Masoudi
- School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney, NSW, Australia
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Walsh K, Jones L, Moody K. Addressing common myths and misconceptions in soft contact lens practice. Clin Exp Optom 2021; 105:459-473. [PMID: 34886744 DOI: 10.1080/08164622.2021.2003693] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
Abstract
Advances in contact lens technology over the past 50 years since the commercialisation of the first soft lenses in 1971 have been incredible, with significant changes in contact lens materials, frequency of replacement, care systems and lens designs occurring. However, despite the widespread availability of contact lenses, penetration rates for those who need vision correction remain in the low single digits and many practitioners seem to hold on to concepts around the potential value of contact lenses that appear based in the dim and distant past and are certainly no longer valid today. This review addresses 10 common 'myths and misconceptions' around soft contact lenses using an evidence-based approach that can hopefully dispel some of these incorrect assumptions.
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Affiliation(s)
- Karen Walsh
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Canada
| | - Lyndon Jones
- Centre for Ocular Research & Education (CORE), School of Optometry and Vision Science, University of Waterloo, Waterloo, Canada.,Centre for Eye and Vision Research (CEVR), 17W Hong Kong Science Park, Shatin, Hong Kong
| | - Kurt Moody
- Johnson & Johnson Vision, Jacksonville, Florida, USA
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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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Mirzapour P, McCanna DJ, Jones L. In vitro analysis of the interaction of tear film inflammatory markers with contemporary contact lens materials. Cont Lens Anterior Eye 2021; 44:101430. [PMID: 33771440 DOI: 10.1016/j.clae.2021.02.016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 02/01/2021] [Accepted: 02/12/2021] [Indexed: 11/17/2022]
Abstract
PURPOSE Several clinical studies have suggested that reusable silicone hydrogel contact lens materials exhibit a two-times increased rate of corneal infiltrative events compared to reusable hydrogels. One potential factor contributing to this complication relates to the differential uptake of tear film-based pro-inflammatory cytokines. The purpose of this study was to use an in vitro assay to investigate whether four pro-inflammatory cytokines differed in their uptake onto six contemporary contact lens materials. METHODS Conventional hydrogel (etafilcon A, omafilcon A) and silicone hydrogel (balafilcon A, comfilcon A, senofilcon A, somofilcon A) contact lens materials were soaked in solutions containing pro-inflammatory cytokines IL-1β, IL-6, IL-8 and TNF-α. Samples of the soaking solutions were collected over various time points and analyzed using the Meso Scale Discovery system, which served as a measurement of cytokine uptake onto the contact lens materials. RESULTS Both conventional hydrogels (etafilcon A, omafilcon A) and two of the four silicone hydrogels tested (balafilcon A, comfilcon A), exhibited some uptake of IL-1β, IL-8 or TNF-α (p < 0.05). Senofilcon A and somofilcon A did not exhibit uptake of any of these cytokines (p > 0.05). There was no uptake of IL-6 onto any of the contact lens materials investigated (p > 0.05). CONCLUSION The contact lens materials tested did not exhibit any uptake of IL-6 and furthermore, did not exhibit more than 10 ± 3 % to 25 ± 12 % uptake of IL-1β, IL-8 or TNF-α. Numerous factors could contribute to the reported increase in corneal infiltrative events with reusable silicone hydrogel materials, however, based on these results, it appears that uptake of these four cytokines are unlikely to contribute to this finding.
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Affiliation(s)
- Parisa Mirzapour
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada.
| | - David J McCanna
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada
| | - Lyndon Jones
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, Ontario N2L 3G1, Canada; Centre for Eye & Vision Research (CEVR), 17W Hong Kong Science Park, Hong Kong
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9
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Efron N, Brennan NA, Chalmers RL, Jones L, Lau C, Morgan PB, Nichols JJ, Szczotka-Flynn LB, Willcox MD. Thirty years of 'quiet eye' with etafilcon A contact lenses. Cont Lens Anterior Eye 2020; 43:285-297. [PMID: 32278644 DOI: 10.1016/j.clae.2020.03.015] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 03/27/2020] [Accepted: 03/28/2020] [Indexed: 11/17/2022]
Abstract
Frequent replacement contact lenses made from the etafilcon A hydrogel lens material were introduced onto the market over 30 years ago, and etafilcon A remains the most widely used hydrogel lens material today. Although the prescribing of silicone hydrogel lenses is increasing, millions of lens wearers globally have been wearing hydrogel lenses for many years and exhibit a physiologically-stable 'quiet eye', with a low profile of adverse events. Hydrogel lenses are demonstrated to maintain a low inflammatory response and infection risk profile during daily wear, which in the case of etafilcon A, may be related to its low modulus, and the naturally-protective, anti-microbial, non-denatured lysozyme absorbed into the lens from the tear fluid. Although improved corneal physiology from decreased hypoxia with silicone hydrogel lenses is well accepted, equivalent levels of corneal oxygenation are maintained during daily wear of low to medium powered hydrogel lenses, which do not impede the daily corneal de-swelling process, and do not induce clinically significant changes in ocular health. Therefore, hydrogel lenses remain an important alternative for daily wear in modern contact lens practice.
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Affiliation(s)
- Nathan Efron
- Institute of Health and Biomedical Innovation, School of Optometry and Vision Science, Queensland University of Technology, Australia.
| | | | | | - Lyndon Jones
- Centre for Ocular Research & Education (CORE), School of Optometry & Vision Science, University of Waterloo, Waterloo, ON, Canada
| | - Charis Lau
- Johnson & Johnson Vision, Inc, Jacksonville, FL, USA
| | - Philip B Morgan
- Eurolens Research, Division of Pharmacy and Optometry, The University of Manchester, UK
| | - Jason J Nichols
- The University of Alabama at Birmingham, School of Optometry, Birmingham, AL, USA
| | - Loretta B Szczotka-Flynn
- University Hospitals Eye Institute, University Hospitals Cleveland Medical Center, Department of Ophthalmology & Visual Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Mark D Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
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10
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Absorption and Extraction of Inflammatory Mediators From Contact Lens Materials. Eye Contact Lens 2019; 45:340-345. [DOI: 10.1097/icl.0000000000000576] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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11
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The influence of protein deposition on contact lens tear film stability. Colloids Surf B Biointerfaces 2019; 180:229-236. [DOI: 10.1016/j.colsurfb.2019.04.051] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 04/18/2019] [Accepted: 04/24/2019] [Indexed: 11/22/2022]
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Walther H, Subbaraman LN, Jones L. Novel in vitro method to determine pre-lens tear break-up time of hydrogel and silicone hydrogel contact lenses. Cont Lens Anterior Eye 2018; 42:178-184. [PMID: 30442514 DOI: 10.1016/j.clae.2018.11.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2018] [Revised: 10/10/2018] [Accepted: 11/04/2018] [Indexed: 10/27/2022]
Abstract
PURPOSE To develop an in vitro model to determine pre-lens non-invasive break-up time (NIBUT) and to subsequently use this method to compare the NIBUT over contemporary daily disposable (DD) contact lenses (CL). METHODS Three silicone hydrogel (SH) and two conventional hydrogel (CH) DD CLs were incubated in an artificial tear solution (ATS). A model blink cell (MBC) was utilised to mimic intermittent air exposure. CLs were repeatedly submerged for 3 seconds (s) and exposed to air for 10 s over periods of 2, 6, 12, and 16 hours (h). NIBUTs (n = 4) were determined out of the blister pack (T0) and at the end of each incubation period. RESULTS Overall, nesofilcon A showed the longest NIBUTs (p < 0.001). At T0, CHs revealed significantly longer NIBUTs (p ≤ 0.001) than SHs. After 2 h, nesofilcon A showed the longest NIBUT, however, this was only statistically significant compared with delefilcon A (p ≤ 0.001). After 6 h, nesofilcon A NIBUT was significantly longer than all other CLs (p ≤ 0.001). Etafilcon A showed a significantly longer NIBUT (p ≤ 0.001) after 12 h and delefilcon A had the longest NIBUT (p ≤ 0.001) after 16 h. Statistically significant (p ≤ 0.05) changes of NIBUT within the lens materials varied between time points. After 16 h, all CLs showed significant reductions in NIBUTs (p ≤ 0.001) in comparison to T0. CONCLUSION NIBUT values reduced gradually over time and varying levels of deposition impacted measured pre-lens NIBUTs. While NIBUT of CH materials are longer immediately out of the blister pack, after tear film exposure, the NIBUTs obtained using this methodology became very similar.
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Affiliation(s)
- Hendrik Walther
- Centre for Ocular Research & Education (CORE, formerly CCLR), School of Optometry and Vision Science, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada.
| | - Lakshman N Subbaraman
- Centre for Ocular Research & Education (CORE, formerly CCLR), School of Optometry and Vision Science, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada
| | - Lyndon Jones
- Centre for Ocular Research & Education (CORE, formerly CCLR), School of Optometry and Vision Science, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada
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13
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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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Guzman G, Bhaway SM, Nugay T, Vogt BD, Cakmak M. Transport-Limited Adsorption of Plasma Proteins on Bimodal Amphiphilic Polymer Co-Networks: Real-Time Studies by Spectroscopic Ellipsometry. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2017; 33:2900-2910. [PMID: 28240027 DOI: 10.1021/acs.langmuir.7b00281] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Traditional hydrogels are commonly limited by poor mechanical properties and low oxygen permeability. Bimodal amphiphilic co-networks (β-APCNs) are a new class of materials that can overcome these limitations by combining hydrophilic and hydrophobic polymer chains within a network of co-continuous morphology. Applications that can benefit from these improved properties include therapeutic contact lenses, enzymatic catalysis supports, and immunoisolation membranes. The continuous hydrophobic phase could potentially increase the adsorption of plasma proteins in blood-contacting medical applications and compromise in vivo material performance, so it is critical to understand the surface characteristics of β-APCNs and adsorption of plasma proteins on β-APCNs. From real-time spectroscopic visible (Vis) ellipsometry measurements, plasma protein adsorption on β-APCNs is shown to be transport-limited. The adsorption of proteins on the β-APCNs is a multistep process with adsorption to the hydrophilic surface initially, followed by diffusion into the material to the internal hydrophilic/hydrophobic interfaces. Increasing the cross-linking of the PDMS phase reduced the protein intake by limiting the transport of large proteins. Moreover, the internalization of the proteins is confirmed by the difference between the surface-adsorbed protein layer determined from XPS and bulk thickness change from Vis ellipsometry, which can differ up to 20-fold. Desorption kinetics depend on the adsorption history with rapid desorption for slow adsorption rates (i.e., slow-diffusing proteins within the network), whereas proteins with fast adsorption kinetics do not readily desorb. This behavior can be directly related to the ability of the protein to spread or reorient, which affects the binding energy required to bind to the internal hydrophobic interfaces.
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Affiliation(s)
- Gustavo Guzman
- Polymer Engineering Department, The University of Akron , Akron, Ohio 44325, United States
| | - Sarang M Bhaway
- Polymer Engineering Department, The University of Akron , Akron, Ohio 44325, United States
| | - Turgut Nugay
- Chemistry Department, Polymer Research Center, Boğaziçi University , Bebek, 34342 Istanbul, Turkey
| | - Bryan D Vogt
- Polymer Engineering Department, The University of Akron , Akron, Ohio 44325, United States
| | - Mukerrem Cakmak
- Polymer Engineering Department, The University of Akron , Akron, Ohio 44325, United States
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15
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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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Mak WC, Cheung KY, Orban J, Lee CJ, Turner APF, Griffith M. Surface-Engineered Contact Lens as an Advanced Theranostic Platform for Modulation and Detection of Viral Infection. ACS APPLIED MATERIALS & INTERFACES 2015; 7:25487-94. [PMID: 26512953 DOI: 10.1021/acsami.5b08644] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
We have demonstrated an entirely new concept of a wearable theranostic device in the form of a contact lens (theranostic lens) with a dual-functional hybrid surface to modulate and detect a pathogenic attack, using a the corneal HSV serotype-1 (HSV-1) model. The theranostic lenses were constructed using a facile layer-by-layer surface engineering technique, keeping the theranostic lenses with good surface wettability, optically transparency, and nontoxic toward human corneal epithelial cells. The theranostic lenses were used to capture and concentrate inflammatory cytokines such as interleukin-1α (IL-1α), which is upregulated during HSV-1 reactivation, for sensitive, noninvasive diagnostics. The theranostic lens also incorporated an antiviral coating to serve as a first line of defense to protect patients against disease. Our strategy tackles major problems in tear diagnostics that are mainly associated with the sampling of a relatively small volume of fluid and the low concentration of biomarkers. The theranostic lenses show effective anti-HSV-1 activity and good analytical performance for the detection of IL-1α, with a limit of detection of 1.43 pg mL(-1) and a wide linear range covering the clinically relevant region. This work offers a new paradigm for "wearable" noninvasive healthcare devices combining "diagnosis" and "protection" against disease, while supporting patient compliance. We believe that this approach holds immense promise as a next-generation point-of-care and decentralized diagnostic/theranostic platform for a range of biomarkers.
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Affiliation(s)
- Wing Cheung Mak
- Integrative Regenerative Medicine Centre, Department of Clinical and Experimental Medicine, Linköping University , 58185 Linköping, Sweden
- Biosensors and Bioelectronics Centre, Department of Physics, Chemistry and Biology, Linköping University , 58183 Linköping, Sweden
| | - Kwan Yee Cheung
- Integrative Regenerative Medicine Centre, Department of Clinical and Experimental Medicine, Linköping University , 58185 Linköping, Sweden
| | - Jenny Orban
- Biosensors and Bioelectronics Centre, Department of Physics, Chemistry and Biology, Linköping University , 58183 Linköping, Sweden
| | - Chyan-Jang Lee
- Integrative Regenerative Medicine Centre, Department of Clinical and Experimental Medicine, Linköping University , 58185 Linköping, Sweden
| | - Anthony P F Turner
- Biosensors and Bioelectronics Centre, Department of Physics, Chemistry and Biology, Linköping University , 58183 Linköping, Sweden
| | - May Griffith
- Integrative Regenerative Medicine Centre, Department of Clinical and Experimental Medicine, Linköping University , 58185 Linköping, Sweden
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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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Powers AD, Han W, Liu B, Palecek SP. Multiplexed tyrosine kinase activity detection in cancer cells using a hydrogel immobilized substrate. Anal Bioanal Chem 2013; 405:5489-99. [PMID: 23624904 DOI: 10.1007/s00216-013-6963-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2013] [Revised: 04/01/2013] [Accepted: 04/02/2013] [Indexed: 12/13/2022]
Abstract
Kinases play a key role in cellular signaling, and the overactivation or overexpression of these kinases has been linked to a variety of cancers. Tyrosine kinase inhibitors treat the mechanism of these cancers by targeting the specific kinases that are overactive. Some patients, however, do not respond to these inhibitors or develop resistance to these inhibitors during treatment. Additionally, even within cancers of the same tissue type, different kinases may be overactive in different patients. For example, some lung cancers overexpress epidermal growth factor receptor (EGFR) and respond to EGFR inhibitors, whereas other lung cancers do not overexpress EGFR and receive no benefit from this treatment. Even among patients exhibiting EGFR overexpression, some do not respond to EGFR kinase inhibitors because other kinases, such as Met kinase, are also overactivated. Here we describe a quantitative and specific multiplexed microfluidic assay using a hydrogel immobilized substrate for measuring the kinase activity of Met and Abl kinase from cancer cells. We immobilized kinase-specific substrates on macroporous hydrogel micropillars in microchannels. These microchannels were incubated with 6 μl of a kinase reaction solution containing cancer cell lysate, and we measured kinase activity via fluorescence detection of a phosphotyrosine antibody. We showed that the assay can specifically measure the activity of both Met and Abl kinase within one microchannel and has the potential to measure the activity of as many as five kinases within one microchannel. The assay also detected Met kinase inhibition from lysates of cancer cells grown in the Met kinase inhibitor PHA665752.
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Affiliation(s)
- Alicia D Powers
- Department of Chemical and Biological Engineering, University of Wisconsin-Madison, 1415 Engineering Drive, Madison, WI 53706, USA
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