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Jung WY, Kim JW, Kim SR, Park M. Heavy metal deposition and parameter change of soft contact lenses by exposure to particulate matter : Parameter change of SCL due to exposure to PM and heavy metal deposition. BMC Ophthalmol 2023; 23:423. [PMID: 37864135 PMCID: PMC10588221 DOI: 10.1186/s12886-023-03154-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2023] [Accepted: 09/25/2023] [Indexed: 10/22/2023] Open
Abstract
BACKGROUND Particulate matter (PM) is known to contain heavy metals and be harmful to the tissues and organs of the human body including the eyes. As such, in this study, the deposition of heavy metals from PM on soft contact lenses was examined, and changes in the lens parameters were further investigated. METHODS Six types of soft contact lenses were exposed to captured PM10 for eight hours. The central thickness, water content, refractive power, and oxygen transmissibility of each contact lens were measured after analyzing the amounts of six heavy metals adsorbed on the contact lenses. RESULTS Lead, manganese, barium, arsenic, vanadium, and cadmium were detected in the captured PM, and only lead was adsorbed on all soft contact lenses except senofilcon C. The largest deposition was 23.21 ± 0.70 (10- 3)µg/lens of the lead on lotrafilcon B. The oxygen transmissibility of nelfilcon A exhibited statistically significant changes, however, it was within the ISO standard tolerance. Nevertheless, changes in the central thickness, water content, and refractive power of each soft contact lens were not statistically significant. CONCLUSIONS This study revealed that a considerable amount of lead in PM10 was adsorbed on soft contact lenses. Amongst lens parameters, only oxygen transmissibility changed significantly. Thus, wearing soft contact lenses under high PM10 concentration might affect the physiology of the eyes.
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Affiliation(s)
- Won Young Jung
- Department of Optometry, Seoul National University of Science and Technology, 232, Gongneung-ro, Nowon-gu, Seoul, Republic of Korea
| | | | - So Ra Kim
- Department of Optometry, Seoul National University of Science and Technology, 232, Gongneung-ro, Nowon-gu, Seoul, Republic of Korea
| | - Mijung Park
- Department of Optometry, Seoul National University of Science and Technology, 232, Gongneung-ro, Nowon-gu, Seoul, Republic of Korea.
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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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The Effect of Different Cleaning Methods on Protein Deposition and Optical Characteristics of Orthokeratology Lenses. Polymers (Basel) 2021; 13:polym13244318. [PMID: 34960869 PMCID: PMC8707220 DOI: 10.3390/polym13244318] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 12/06/2021] [Accepted: 12/07/2021] [Indexed: 11/29/2022] Open
Abstract
Orthokeratology lenses are commonly used for myopia control, especially in children. Tear lipids and proteins are immediately adsorbed when the lens is put on the cornea, and protein deposition may cause discomfort or infection. Therefore, we established an in vitro protein deposition analysis by mimicking the current cleaning methods for orthokeratology lens wearers for both short-term and long-term period. The results showed that the amounts of tear proteins accumulated daily and achieved a balance after 14 days when the lens was rubbed to clean or not. Protein deposition also affected the optical characteristics of the lens regardless of cleaning methods. Our results provided an in vitro analysis for protein deposition on the lens, and they may provide a potential effective method for developing care solutions or methods that can more effectively remove tear components from orthokeratology lenses.
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Işıkver Y, Saraydın D. Smart Hydrogels: Preparation, Characterization, and Determination of Transition Points of Crosslinked N-Isopropyl Acrylamide/Acrylamide/Carboxylic Acids Polymers. Gels 2021; 7:113. [PMID: 34449617 PMCID: PMC8395758 DOI: 10.3390/gels7030113] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 07/28/2021] [Accepted: 08/04/2021] [Indexed: 12/20/2022] Open
Abstract
Smart hydrogels (SH) were prepared by thermal free radical polymerization of N-isopropyl acrylamide (NIPAAm), acrylamide (AAm) with acrylic acid (A) or maleic acid (M), and N,N'-methylene bisacrylamide. Spectroscopic and thermal characterizations of SHs were performed using FTIR, TGA, and DSC. To determine the effects of SHs on swelling characteristics, swelling studies were performed in different solvents, solutions, temperatures, pHs, and ionic strengths. In addition, cycle equilibrium swelling studies were carried out at different temperatures and pHs. The temperature and pH transition points of SHs are calculated using a sigmoidal equation. The pH transition points were calculated as 5.2 and 4.2 for SH-M and SH-A, respectively. The NIPAAm/AAm hydrogel exhibits a critical solution temperature (LCST) of 28.35 °C, while the SH-A and SH-M hydrogels exhibit the LCST of 34.215 °C and 28.798 °C, respectively, and the LCST of SH-A is close to the body. temperature. Commercial (CHSA) and blood human serum albumin (BHSA) were used to find the adsorption properties of biopolymers on SHs. SH-M was the most efficient SH, adsorbing 49% of CHSA while absorbing 16% of BHSA. In conclusion, the sigmoidal equation or Gaussian approach can be a useful tool for chemists, chemical engineers, polymer and plastics scientists to find the transition points of smart hydrogels.
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Affiliation(s)
| | - Dursun Saraydın
- Chemistry Department, Science Faculty, Sivas Cumhuriyet University, Sivas 58140, Turkey;
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5
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Su CY, Yeh LK, Fan TW, Lai CC, Fang HW. Albumin Acts as a Lubricant on the Surface of Hydrogel and Silicone Hydrogel Contact Lenses. Polymers (Basel) 2021; 13:polym13132051. [PMID: 34201543 PMCID: PMC8271981 DOI: 10.3390/polym13132051] [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: 06/09/2021] [Revised: 06/21/2021] [Accepted: 06/21/2021] [Indexed: 11/16/2022] Open
Abstract
Feeling comfortable is the greatest concern for contact lens wearers, and it has been suggested that in vivo comfort could be corresponded to the in vitro friction coefficient of contact lenses. How tear albumin could affect the friction coefficient of silicone hydrogel and hydrogel contact lenses was analyzed by sliding a lens against a quartz glass in normal and extremely high concentration of albumin solution. Albumin deposition testing and surface roughness analysis were also conducted. The results showed that the friction coefficient of tested contact lenses did not correspond to both the albumin deposition amount and surface roughness, but we proposed a model of how albumin might act as a lubricant on the surface of some hydrogel and silicone hydrogel contact lenses. In conclusion, albumin provided lubrication for silicone hydrogel contact lenses regardless of albumin concentrations, while albumin only acted as a lubricant for hydrogel contact under normal concentration.
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Affiliation(s)
- Chen-Ying Su
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, 1, Sec. 3, Zhongxiao E. Rd., Taipei 10608, Taiwan; (C.-Y.S.); (T.-W.F.)
| | - Lung-Kun Yeh
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, No. 5, Fuxing St., Taoyuan 333, Taiwan; (L.-K.Y.); (C.-C.L.)
- College of Medicine, Chang Gung University, No. 259, Wenhua 1st Rd., Taoyuan 333, Taiwan
| | - Tzu-Wei Fan
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, 1, Sec. 3, Zhongxiao E. Rd., Taipei 10608, Taiwan; (C.-Y.S.); (T.-W.F.)
| | - Chi-Chun Lai
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou, No. 5, Fuxing St., Taoyuan 333, Taiwan; (L.-K.Y.); (C.-C.L.)
- College of Medicine, Chang Gung University, No. 259, Wenhua 1st Rd., Taoyuan 333, Taiwan
| | - Hsu-Wei Fang
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, 1, Sec. 3, Zhongxiao E. Rd., Taipei 10608, Taiwan; (C.-Y.S.); (T.-W.F.)
- Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, No. 35, Keyan Road, Zhunan Town, Miaoli County 35053, Taiwan
- Correspondence:
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Braune S, Latour RA, Reinthaler M, Landmesser U, Lendlein A, Jung F. In Vitro Thrombogenicity Testing of Biomaterials. Adv Healthc Mater 2019; 8:e1900527. [PMID: 31612646 DOI: 10.1002/adhm.201900527] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Revised: 08/15/2019] [Indexed: 12/29/2022]
Abstract
The short- and long-term thrombogenicity of implant materials is still unpredictable, which is a significant challenge for the treatment of cardiovascular diseases. A knowledge-based approach for implementing biofunctions in materials requires a detailed understanding of the medical device in the biological system. In particular, the interplay between material and blood components/cells as well as standardized and commonly acknowledged in vitro test methods allowing a reproducible categorization of the material thrombogenicity requires further attention. Here, the status of in vitro thrombogenicity testing methods for biomaterials is reviewed, particularly taking in view the preparation of test materials and references, the selection and characterization of donors and blood samples, the prerequisites for reproducible approaches and applied test systems. Recent joint approaches in finding common standards for a reproducible testing are summarized and perspectives for a more disease oriented in vitro thrombogenicity testing are discussed.
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Affiliation(s)
- Steffen Braune
- Institute of Biomaterial Science and Berlin‐Brandenburg Centre for Regenerative Therapies (BCRT)Helmholtz‐Zentrum Geesthacht Kantstrasse 55 14513 Teltow Germany
| | - Robert A. Latour
- Rhodes Engineering Research CenterDepartment of BioengineeringClemson University Clemson SC 29634 USA
| | - Markus Reinthaler
- Institute of Biomaterial Science and Berlin‐Brandenburg Centre for Regenerative Therapies (BCRT)Helmholtz‐Zentrum Geesthacht Kantstrasse 55 14513 Teltow Germany
- Department for CardiologyCharité UniversitätsmedizinCampus Benjamin Franklin Hindenburgdamm 30 12203 Berlin Germany
| | - Ulf Landmesser
- Department for CardiologyCharité UniversitätsmedizinCampus Benjamin Franklin Hindenburgdamm 30 12203 Berlin Germany
| | - Andreas Lendlein
- Institute of Biomaterial Science and Berlin‐Brandenburg Centre for Regenerative Therapies (BCRT)Helmholtz‐Zentrum Geesthacht Kantstrasse 55 14513 Teltow Germany
- Institute of ChemistryUniversity of Potsdam Karl‐Liebknecht‐Strasse 24‐25 14476 Potsdam Germany
- Helmholtz Virtual Institute “Multifunctional Biomaterials for Medicine”Helmholtz‐Zentrum Geesthacht Kantstrasse 55 14513 Teltow Germany
| | - Friedrich Jung
- Institute of Biomaterial Science and Berlin‐Brandenburg Centre for Regenerative Therapies (BCRT)Helmholtz‐Zentrum Geesthacht Kantstrasse 55 14513 Teltow Germany
- Helmholtz Virtual Institute “Multifunctional Biomaterials for Medicine”Helmholtz‐Zentrum Geesthacht Kantstrasse 55 14513 Teltow Germany
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Su CY, Lai CC, Yeh LK, Li KY, Shih BW, Tseng CL, Fang HW. The characteristics of a preservative-free contact lens care solution on lysozyme adsorption and interfacial friction behavior. Colloids Surf B Biointerfaces 2018; 171:538-543. [PMID: 30096475 DOI: 10.1016/j.colsurfb.2018.07.076] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 06/25/2018] [Accepted: 07/31/2018] [Indexed: 11/18/2022]
Abstract
The population of soft contact lens wearers is increasing, thus the issues of feeling comfortable and contact lens-induced clinical symptoms are concerned. Both lysozyme deposition and mechanical friction among contact lens and the eye can induce discomfort and eye conditions. Therefore, we characterized our developed preservative-free contact lens care solution on lysozyme adsorption and lubrication. Two distinct lens materials were washed with the care solution after being soaked in lysozyme, as well as were rubbed against the glass in the presence of lysozyme and the care solution for measuring the friction coefficient. Our results demonstrated that the preservative-free contact lens care solution can be applied as a potential lubricant for a specific type of soft contact lenses.
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Affiliation(s)
- Chen-Ying Su
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, 1, Sec. 3, Zhongxiao E. Rd., Taipei 10608, Taiwan.
| | - Chi-Chun Lai
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou. No. 5, Fuxing St., Taoyuan 333, Taiwan; College of Medicine, Chang Gung University, No. 259, Wenhua 1st Rd., Taoyuan 333, Taiwan
| | - Lung-Kun Yeh
- Department of Ophthalmology, Chang Gung Memorial Hospital, Linkou. No. 5, Fuxing St., Taoyuan 333, Taiwan; College of Medicine, Chang Gung University, No. 259, Wenhua 1st Rd., Taoyuan 333, Taiwan
| | - Kuan-Yi Li
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, 1, Sec. 3, Zhongxiao E. Rd., Taipei 10608, Taiwan
| | - Bo-Wu Shih
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, 1, Sec. 3, Zhongxiao E. Rd., Taipei 10608, Taiwan
| | - Ching-Li Tseng
- Graduate Institute of Biomedical Materials and Tissue Engineering, College of Biomedical Engineering, Taipei Medical University, No. 250, Wu-Hsing St., Taipei 110, Taiwan
| | - Hsu-Wei Fang
- Department of Chemical Engineering and Biotechnology, National Taipei University of Technology, 1, Sec. 3, Zhongxiao E. Rd., Taipei 10608, Taiwan; Institute of Biomedical Engineering and Nanomedicine, National Health Research Institutes, No. 35, Keyan Road, Zhunan Town, Miaoli County 35053, Taiwan.
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In Vitro Effect of Lysozyme on Albumin Deposition to Hydrogel Contact Lens Materials. Optom Vis Sci 2017; 94:1047-1051. [PMID: 29040199 DOI: 10.1097/opx.0000000000001137] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
SIGNIFICANCE Albumin deposition on contact lenses could be detrimental to contact lens (CL) wear because this may increase the risk of bacterial binding and reduce comfort. Lysozyme deposition on selected lens materials would reduce albumin deposition on lenses. PURPOSE This study aims to determine if lysozyme deposition on CLs could act as a barrier against subsequent albumin adsorption, using an in vitro model. METHODS Six hydrogel CL materials (etafilcon A, polymacon, nelfilcon A, omafilcon A, ocufilcon B, and nesofilcon A) were evaluated. Four CLs of each type were soaked in lysozyme solution for 16 hours at 37°C. Lysozyme-coated lenses were then placed in vials with 1.5 mL of artificial tear solution containing I-labeled albumin for 16 hours at 37°C with shaking. Four uncoated lenses of each type were used as controls. Lenses soaked in radiolabeled albumin were rinsed in a phosphate-buffered saline solution, and radioactive counts were measured directly on lenses using a gamma counter. Albumin uptake on lenses was measured using a calibration curve by plotting radioactive counts versus protein concentration. RESULTS Results are reported as mean ± SD. Lysozyme-coated etafilcon A lenses exhibited lower levels of deposited albumin than uncoated etafilcon A lenses (58 ± 12 vs. 84 ± 5 ng/lens; P < .05). There were no differences in albumin adsorption between control (uncoated) and lysozyme-coated polymacon (105 ± 10 vs. 110 ± 34 ng/lens), nelfilcon A (51 ± 7 vs. 42 ± 20 ng/lens), omafilcon A (90 ± 20 vs. 80 ± 38 ng/lens), ocufilcon B (87 ± 20 vs. 115 ± 50 ng/lens), and nesofilcon A (170 ± 29 vs. 161 ± 10 ng/lens) lens materials (P > .05). Uncoated nesofilcon A lenses deposited the highest amount of albumin when compared with other uncoated lenses (P < .05). CONCLUSIONS This study demonstrates that lysozyme deposited onto etafilcon A resists the deposition of albumin, which may potentially be beneficial to CL wearers.
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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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Omali NB, Subbaraman LN, Coles-Brennan C, Fadli Z, Jones LW. Biological and Clinical Implications of Lysozyme Deposition on Soft Contact Lenses. Optom Vis Sci 2015; 92:750-7. [PMID: 26002002 PMCID: PMC5638422 DOI: 10.1097/opx.0000000000000615] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2014] [Accepted: 02/17/2015] [Indexed: 12/28/2022] Open
Abstract
Within a few minutes of wear, contact lenses become rapidly coated with a variety of tear film components, including proteins, lipids, and mucins. Tears have a rich and complex composition, allowing a wide range of interactions and competitive processes, with the first event observed at the interface between a contact lens and tear fluid being protein adsorption. Protein adsorption on hydrogel contact lenses is a complex process involving a variety of factors relating to both the protein in question and the lens material. Among tear proteins, lysozyme is a major protein that has both antibacterial and anti-inflammatory functions. Contact lens materials that have high ionicity and high water content have an increased affinity to accumulate lysozyme during wear, when compared with other soft lens materials, notably silicone hydrogel lenses. This review provides an overview of tear film proteins, with a specific focus on lysozyme, and examines various factors that influence protein deposition on contact lenses. In addition, the impact of lysozyme deposition on various ocular physiological responses and bacterial adhesion to lenses and the interaction of lysozyme with other tear proteins are reviewed. This comprehensive review suggests that deposition of lysozyme on contact lens materials may provide a number of beneficial effects during contact lens wear.
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11
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Pezzotti G. Bioceramics for Hip Joints: The Physical Chemistry Viewpoint. MATERIALS (BASEL, SWITZERLAND) 2014; 7:4367-4410. [PMID: 28788682 PMCID: PMC5455897 DOI: 10.3390/ma7064367] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/01/2014] [Revised: 05/14/2014] [Accepted: 05/26/2014] [Indexed: 11/16/2022]
Abstract
Which intrinsic biomaterial parameter governs and, if quantitatively monitored, could reveal to us the actual lifetime potential of advanced hip joint bearing materials? An answer to this crucial question is searched for in this paper, which identifies ceramic bearings as the most innovative biomaterials in hip arthroplasty. It is shown that, if in vivo exposures comparable to human lifetimes are actually searched for, then fundamental issues should lie in the physical chemistry aspects of biomaterial surfaces. Besides searching for improvements in the phenomenological response of biomaterials to engineering protocols, hip joint components should also be designed to satisfy precise stability requirements in the stoichiometric behavior of their surfaces when exposed to extreme chemical and micromechanical conditions. New spectroscopic protocols have enabled us to visualize surface stoichiometry at the molecular scale, which is shown to be the key for assessing bioceramics with elongated lifetimes with respect to the primitive alumina biomaterials used in the past.
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Affiliation(s)
- Giuseppe Pezzotti
- Ceramic Physics Laboratory, Kyoto Institute of Technology, Sakyo-ku, Matsugasaki, Kyoto 606-8126, Japan.
- Department of Orthopedic Research, Loma Linda University, 11406 Loma Linda Drive, Suite 606 Loma Linda, CA 92354, USA.
- The Center for Advanced Medical Engineering and Informatics, Osaka University, Yamadaoka, Suita, Osaka 565-0871, Japan.
- Department of Molecular Cell Physiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kamigyo-ku, 465 Kajii-cho, Kawaramachi dori, Kyoto 602-0841, Japan .
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Chandler-Temple A, Kingshott P, Wentrup-Byrne E, Cassady AI, Grøndahl L. Surface chemistry of grafted expanded poly(tetrafluoroethylene) membranes modifies thein vitroproinflammatory response in macrophages. J Biomed Mater Res A 2012; 101:1047-58. [DOI: 10.1002/jbm.a.34408] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Revised: 07/26/2012] [Accepted: 07/30/2012] [Indexed: 12/19/2022]
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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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15
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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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16
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Takahashi Y, Zhu W, Sugano N, Pezzotti G. On the role of oxygen vacancies, aliovalent ions and lattice strain in the in vivo wear behavior of alumina hip joints. J Mech Behav Biomed Mater 2011; 4:993-1003. [DOI: 10.1016/j.jmbbm.2011.02.014] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2010] [Revised: 02/21/2011] [Accepted: 02/22/2011] [Indexed: 11/28/2022]
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17
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Luensmann D, Heynen M, Liu L, Sheardown H, Jones L. Determination of albumin sorption to intraocular lenses by radiolabeling and confocal laser scanning microscopy. J Cataract Refract Surg 2010; 35:2000-7. [PMID: 19878835 DOI: 10.1016/j.jcrs.2009.05.052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2009] [Revised: 05/22/2009] [Accepted: 05/26/2009] [Indexed: 11/24/2022]
Abstract
PURPOSE To determine albumin adsorption profiles and penetration depth of 3 intraocular lens (IOL) materials over time using confocal laser scanning microscopy (CLSM) and radiolabeling. SETTING Centre for Contact Lens Research, School of Optometry, and Department of Biology, University of Waterloo, Waterloo, Ontario, Canada. METHODS Poly(methyl methacrylate) (PMMA), silicone, and foldable hydrophilic acrylic IOLs were incubated in 0.5 mg/mL bovine serum albumin (BSA) for 1, 7, and 14 days. The BSA was conjugated with lucifer yellow VS to allow identification of the protein location by fluorescent imaging with CLSM. Next, the protein uptake was quantified using 2% (125)I-labeled BSA. RESULTS Confocal laser scanning microscopy showed increasing BSA uptake for silicone and PMMA IOLs after 14 days of incubation (P<.05), with an apparent penetration depth of 8.7 microm +/- 1.9 (SD) and 9.2 +/- 1.4 microm, respectively. For hydrophilic acrylic IOLs, BSA was detected at a depth of 38 +/- 7.4 microm after 1 day, followed by an increase to 192.7 +/- 16.2 microm after 14 days. Despite the penetration depth into the hydrophilic acrylic IOLs, quantitative results confirmed that PMMA and hydrophilic acrylic deposited significantly less BSA (mean 278.3 +/- 41.7 ng and 296.5 +/- 33.1 ng, respectively) than silicone IOLs (mean 392.6 +/- 37.6 ng) (P<.05). CONCLUSIONS Silicone and PMMA IOL materials showed BSA sorption near the lens surface only, while BSA penetrated deep into the hydrophilic acrylic IOL matrix. Combining the qualitative CLSM method and quantitative radiolabeling technique provided detailed information on protein interactions with implantable biomaterials.
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Affiliation(s)
- Doerte Luensmann
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada.
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In Vitro Adsorption of Tear Proteins to Hydroxyethyl Methacrylate-Based Contact Lens Materials. Eye Contact Lens 2009; 35:320-8. [DOI: 10.1097/icl.0b013e3181becd3c] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Senchyna M, Jones L, Louie D, May C, Forbes I, Glasier MA. Quantitative and conformational characterization of lysozyme deposited on balafilcon and etafilcon contact lens materials. Curr Eye Res 2009; 28:25-36. [PMID: 14704911 DOI: 10.1076/ceyr.28.1.25.23496] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
PURPOSE To determine whether differences in lysozyme deposition and/or activity exist on worn etafilcon and balafilcon contact lenses following care with a polyquaternium-based system (PQ) or a polyhexanide-based system (PHMB). METHODS Following acid-based deposit extraction, lysozyme concentration was determined via Western blotting and lysozyme activity was determined by a micrococcyl assay. RESULTS Lysozyme deposition on etafilcon lenses was greater following disinfection with the PHMB-based system (1551 +/- 371 micro g/lens vs 935 +/- 271 micro g/lens; p < 0.001). Deposition on balafilcon lenses was not influenced by the care regimen (10 +/- 3.5 micro g/lens vs 10 +/- 5 micro g/lens; p = 0.89). For both materials, the percentage of denatured lysozyme was greater when they were exposed to the PHMB-based system (28 vs 21%; p = 0.05 (etafilcon) and 57 vs 40%; p = 0.04 (balafilcon)). CONCLUSIONS The quantity and conformation of lysozyme deposited on hydrogel contact lens materials is significantly influenced by both lens material and care regimen.
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Affiliation(s)
- Michelle Senchyna
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada.
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Glasier MA, Keech A, Sheardown H, Subbaraman LN, Jones L. Conformational and Quantitative Characterization of Lysozyme Extracted from Galyfilcon and Senofilcon Silicone Hydrogel Contact Lenses. Curr Eye Res 2009; 33:1-11. [DOI: 10.1080/02713680701830278] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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21
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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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22
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23
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Quartz crystal microbalance study of protein adsorption kinetics on poly(2-hydroxyethyl methacrylate). J Colloid Interface Sci 2008; 325:157-64. [DOI: 10.1016/j.jcis.2008.05.052] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2008] [Revised: 04/18/2008] [Accepted: 05/28/2008] [Indexed: 11/19/2022]
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24
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Albumin adsorption to contact lens materials: A review. Cont Lens Anterior Eye 2008; 31:179-87. [DOI: 10.1016/j.clae.2008.05.004] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2007] [Revised: 05/12/2008] [Accepted: 05/15/2008] [Indexed: 11/21/2022]
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25
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Lord MS, Pasqui D, Barbucci R, Milthorpe BK. Protein Adsorption on Derivatives of Hyaluronan. ACTA ACUST UNITED AC 2008. [DOI: 10.1002/masy.200850604] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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26
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Calcification of Hydroview H60M intraocular lenses: aqueous humor analysis and comparisons with other intraocular lens materials. J Cataract Refract Surg 2008; 34:80-6. [PMID: 18165086 DOI: 10.1016/j.jcrs.2007.08.020] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2007] [Accepted: 08/08/2007] [Indexed: 11/23/2022]
Abstract
PURPOSE To compare the level of calcification on Hydroview H60M hydrophilic acrylic intraocular lenses (IOLs) (Bausch & Lomb) and other IOL materials. SETTING Omori Medical Center, Department of Ophthalmology, Toho University, Tokyo, Japan. METHODS The levels of calcification on Hydroview H60M hydrophilic acrylic IOLs, AcrySof SA60AT hydrophobic acrylic IOLs (Alcon Surgical, Inc.), Sensar AR40e hydrophobic acrylic IOLs (Advanced Medical Optics), ClariFlex (Advanced Medical Optics) silicone IOLs, and the MeniFlex ENV13 (Menicon) poly(methyl methacrylate) IOLs were compared in a calcium phosphate solution containing albumin. In a concentration-change experiment, the calcium and phosphate concentration levels were changed and the results observed by scanning electron microscopy. RESULTS The Hydroview H60M IOL had the largest amount of deposits. Small amounts of deposits were found on the other IOLs in the following decreasing order: AcrySof SA60AT, Sensar AR40e, ClariFlex, and MeniFlex ENV13. The amount of deposits on the Hydroview H60M IOLs was statistically significantly greater than the amount on the other IOLs (P<.01). CONCLUSIONS The hydrophilic acrylic IOLs (Hydroview H60M) had significantly higher amounts of calcified deposits than IOLs of other materials, indicating that hydrophilic acrylic IOLs easily accumulate calcified deposits in the body when the concentrations of calcium, phosphate, and albumin in the aqueous humor fluctuate as a result of a blood-aqueous barrier breakdown.
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Suwala M, Glasier MA, Subbaraman LN, Jones L. Quantity and Conformation of Lysozyme Deposited on Conventional and Silicone Hydrogel Contact Lens Materials Using an In Vitro Model. Eye Contact Lens 2007; 33:138-43. [PMID: 17502748 DOI: 10.1097/01.icl.0000244155.87409.f6] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE To determine the activity of hen egg lysozyme (HEL) deposited on conventional and silicone hydrogel contact lens materials by using an in vitro model. METHODS ACUVUE 2 (etafilcon A), PureVision (balafilcon A), ACUVUE Advance (galyfilcon A), Focus NIGHT & DAY (lotrafilcon A), O2 Optix (lotrafilcon B), Proclear (omafilcon A), and ACUVUE OASYS (senofilcon A) contact lenses were deposited in vitro in a phosphate-buffered solution (PBS) containing 2 mg/mL HEL. Lenses were briefly rinsed in PBS to remove unbound material and extracted in a mixture of acetonitrile and trifluoroacetic acid. After lyophilization, extracts were examined for lysozyme activity by micrococcal assay and total protein by Western blot. RESULTS In terms of total protein accumulation, ACUVUE 2 showed the most, with 1,800 microg per lens. Proclear was next, with 68 microg per lens, and Focus NIGHT & DAY showed the least, with 2 microg per lens. ACUVUE Advance, ACUVUE OASYS, and O2 Optix accumulated similar amounts of lysozyme, at approximately 6 microg per lens. Lysozyme deposited on ACUVUE 2 showed the greatest activity (91% +/- 5%), and this result was statistically different from all other lens types (P<0.001). Lysozyme deposited on Focus NIGHT & DAY (24% +/- 5%) and O2 Optix (23% +/- 11%) showed the lowest activity. Lysozyme deposits on other lens materials showed intermediate activity (ACUVUE Advance, 60% +/- 15%; ACUVUE OASYS, 51% +/- 9%; PureVision, 58% +/- 8%; and Proclear, 38% +/- 3%). CONCLUSIONS Silicone hydrogel lenses acquire less lysozyme deposit than conventional group II (Proclear) or group IV (ACUVUE 2) lenses do, and the levels of activity of the lysozyme are highly variable between materials.
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Affiliation(s)
- Maciej Suwala
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada
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29
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Lorentz H, Jones L. Lipid Deposition on Hydrogel Contact Lenses: How History Can Help Us Today. Optom Vis Sci 2007; 84:286-95. [PMID: 17435512 DOI: 10.1097/opx.0b013e3180485d4b] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
The tear film is a complex fluid that is precisely maintained and which is essential to the health of the ocular surface. One of the major components of the tear film is lipid, which is produced by the meibomian glands and serves many important functions on the ocular surface. It is estimated that there are more than 45 individual lipids within the tear film, which vary greatly in their structure and properties. The composition of the lipid within the tear film has an enormous influence on the stability of the tear film, with a subsequent impact on the occurrence of dry eye and the ultimate success of contact lens wear. The purpose of this review article is to describe the composition of the tear film lipids and their interaction with contact lens materials, with a particular emphasis on how the chemistry of novel silicone hydrogel materials has resulted in clinicians needing to understand the deposition of lipids onto contact lenses and how they may best manage this complication.
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Affiliation(s)
- Holly Lorentz
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada.
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Zainuddin Z, Hill DJT, Chirila TV, Whittaker AK, Kemp A. Experimental Calcification of HEMA-Based Hydrogels in the Presence of Albumin and a Comparison to the in Vivo Calcification. Biomacromolecules 2006; 7:1758-65. [PMID: 16768395 DOI: 10.1021/bm060075g] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The precipitation patterns and characteristics of calcium phosphate (CaP) phases deposited on HEMA-based hydrogels upon incubation in simulated body fluid (SBF-2) containing a protein (human serum albumin) have been investigated in relation to the calcification in an organic-free medium (SBF-1) and to that occurring after subcutaneous implantation in rats. In SBF-2, the deposits occurred exclusively as a peripheral layer on the surface of the hydrogels and consisted mainly of "precipitated hydroxyapatite", a species deficient in calcium and hydroxyl ions, similarly to the deposits formed on the implanted hydrogels, where the deposited layer was thicker. In SBF-1, the deposits were mainly of brushite type. There was no evidence that albumin penetrated the interstices of hydrogels. As the X-ray diffraction patterns of the CaP deposits generated in SBF-2 showed a similar nature with those formed on the implanted hydrogel, it was concluded that the calcification in SBF-2 can mimic to a reliable extent the calcification process taking place in a biological environment.
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Affiliation(s)
- Zainuddin Zainuddin
- Department of Chemistry, University of Queensland, Santa Lucia, Brisbane, Queensland 4072, Australia
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31
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Subbaraman LN, Bayer S, Glasier MA, Lorentz H, Senchyna M, Jones L. Rewetting Drops Containing Surface Active Agents Improve the Clinical Performance of Silicone Hydrogel Contact Lenses. Optom Vis Sci 2006; 83:143-51. [PMID: 16534456 DOI: 10.1097/01.opx.0000204513.76568.57] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
PURPOSE The purpose of this study was to investigate the impact of using a rewetting drop (RWD) containing surface active agents (OPTI-FREE RepleniSH; Alcon, Fort Worth, TX) on the clinical performance and protein deposition when using a continuous-wear (CW) silicone hydrogel (SH) contact lens. METHODS Subjects wore lotrafilcon A SH lenses on a 30-day CW basis for two consecutive 1-month periods while inserting either 0.9% unpreserved unit-dose saline (control) or multidose OPTI-FREE RepleniSH (test RWD). Subjective comfort and symptoms were assessed after 2 and 4 weeks with each product. After 1 month of wear with each product, lenses were collected and analyzed in the laboratory for total protein, total lysozyme, and percentage of denatured lysozyme. RESULTS Symptoms of dryness and comfort varied across the day regardless of drop type (p < 0.001) with dryness being maximal on waking, least in the middle of the day, and increased towards the evening. The test RWD provided greater comfort on insertion (p = 0.02), better visual quality (p < 0.01), and less mucous discharge on waking (p = 0.02) than the control product. Lysozyme deposition was significantly reduced after the use of the test RWD as compared to saline (0.73 +/- 0.5 microg/lens vs. 1.14 +/- 0.7 microg/lens; p < 0.001) as was total protein deposition (1.17 +/- 0.7 microg/lens vs. 1.86 +/- 0.8 microg/lens; p < 0.001). Lysozyme denaturation was also reduced with the use of the test RWD compared with the control (76 +/- 10% vs. 85 +/- 7%; p < 0.01). CONCLUSIONS The use of a RWD containing surface active agents provided greater subjective satisfaction, reduced lysozyme and total protein deposition, and reduced denatured lysozyme than a RWD containing saline alone.
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Affiliation(s)
- Lakshman N Subbaraman
- Centre for Contact Lens Research, School of Optometry, University of Waterloo, Waterloo, Ontario, Canada
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Lord MS, Stenzel MH, Simmons A, Milthorpe BK. The effect of charged groups on protein interactions with poly(HEMA) hydrogels. Biomaterials 2006; 27:567-75. [PMID: 16054682 DOI: 10.1016/j.biomaterials.2005.06.010] [Citation(s) in RCA: 90] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2005] [Accepted: 06/20/2005] [Indexed: 10/25/2022]
Abstract
Proteins, lipids and other biomolecules interact strongly with the acrylic-based biomaterials used for contact lenses. Although hydrogels are nominally resistant to protein fouling, many studies have reported considerable amounts of protein bound to poly(2-hydroxyethylmethacrylate) (PHEMA) lenses. This study examined the binding of a series of biomolecules (tear protein analogues, mucin and cholesterol) to poly(methylmethacrylate) (PMMA) and three HEMA-based hydrogels (PHEMA, HEMA plus methacrylic acid (P(HEMA-MAA)), HEMA plus methacrylic acid plus N-vinylpyrrolidone (P(HEMA-MAA-NVP))) by use of a quartz crystal microbalance with dissipation (QCM-D) monitoring. The QCM-D estimates changes in the mass and viscous constant for the adsorbed layer through measurements of frequency and dissipation. Protein interaction with each of the test materials caused a net increase in mass of the material indicating protein binding except for lysozyme interacting with P(HEMA-MAA). A net decrease in mass was observed for lysozyme interacting with P(HEMA-MAA) which may be ascribed to lysozyme collapsing the hydrogel by expelling water. A net mass decrease was observed for cholesterol interacting with each of the hydrogel materials, while a mass increase was observed on PMMA.
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Affiliation(s)
- Megan S Lord
- Graduate School of Biomedical Engineering, The University of New South Wales, Sydney NSW 2052, Australia.
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Kim SH, Opdahl A, Marmo C, Somorjai GA. AFM and SFG studies of pHEMA-based hydrogel contact lens surfaces in saline solution: adhesion, friction, and the presence of non-crosslinked polymer chains at the surface. Biomaterials 2002; 23:1657-66. [PMID: 11922469 DOI: 10.1016/s0142-9612(01)00292-7] [Citation(s) in RCA: 121] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The surfaces of two types of soft contact lenses neutral and ionic hydrogels--were characterized by atomic force microscopy (AFM) and sum-frequency-generation (SFG) vibrational spectroscopy. AFM measurements in saline solution showed that the presence of ionic functional groups at the surface lowered the friction and adhesion to a hydrophobic polystyrene tip. This was attributed to the specific interactions of water and the molecular orientation of hydrogel chains at the surface. Friction and adhesion behavior also revealed the presence of domains of non-crosslinked polymer chains at the lens surface. SFG showed that the lens surface became partially dehydrated upon exposure to air. On this partially dehydrated lens surface, the non-crosslinked domains exhibited low friction and adhesion in AFM. Fully hydrated in saline solution, the non-crosslinked domains extended more than tens of nanometers into solution and were mobile.
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Affiliation(s)
- Seong Han Kim
- Department of Chemistry, University of California at Berkley, 94720, USA
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Kim SH, Marmo C, Somorjai GA. Friction studies of hydrogel contact lenses using AFM: non-crosslinked polymers of low friction at the surface. Biomaterials 2001; 22:3285-94. [PMID: 11700800 DOI: 10.1016/s0142-9612(01)00175-2] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The surface of soft contact lenses made of crosslinked poly(2-hydroxyethyl methacrylate). pHEMA, has been investigated with atomic force microscopy in contact mode. The friction force and adhesive force measurements were able to differentiate the non-crosslinked pHEMA chains from the surface of the crosslinked pHEMA networks. These non-crosslinked pHEMA chains at the surface were anchored to the crosslinked pHEMA network, most likely by entanglement and their surfaces were about 2-4nm higher than the surrounding surface in a dehydrated state. In saline solution, the surface friction and adhesive force of the contact lens were significantly reduced compared to those measured for the surface-dehydrated contact lens.
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Affiliation(s)
- S H Kim
- Department of Chemistry University of California at Berkeley, 94720, USA
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