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Masoudi S, Willcox M. A method for studying lipid adsorption to silicone hydrogel contact lenses. BIOFOULING 2021; 37:862-878. [PMID: 34615411 DOI: 10.1080/08927014.2021.1978433] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 08/30/2021] [Accepted: 09/02/2021] [Indexed: 06/13/2023]
Abstract
The aim of this study was to develop an experimental methodology to measure lipid deposition with contact lenses. Contact lenses were incubated in a lipid solution. The amount and types of adsorbed lipids were assessed using mass spectrometry and confocal microscopy. The recovery of lipids from lenses varied with lipid and lens type. Most non-polar and polar lipids were desorbed from lenses during the first 5 min of extraction. Fluorescently labelled phosphatidylcholine bound within the matrix of Senofilcon A lenses but to the surface of Lotrafilcon B lenses, whereas fluorescently labelled cholesteryl ester was found throughout both lenses. The efficacy of extraction of lipids from contact lenses varies for different lipid classes and different lens materials. Differences in the amount and time of lipid desorption probably resulted from the strength of the bond between lipid and lens polymer and the depth of adsorption of lipid in the polymer.
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Affiliation(s)
- Simin Masoudi
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
| | - Mark Willcox
- School of Optometry and Vision Science, University of New South Wales, Sydney, Australia
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Miglio F, Ponzini E, Zeri F, Borghesi A, Tavazzi S. In vitro affinity for nicotine of soft contact lenses of different materials. Cont Lens Anterior Eye 2021; 45:101490. [PMID: 34294534 DOI: 10.1016/j.clae.2021.101490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 07/02/2021] [Accepted: 07/07/2021] [Indexed: 02/06/2023]
Abstract
Smoking is a risk factor for the development of microbial keratitis and corneal infiltrates in contact lens (CL) wearers. It is still unknown if this risk is directly associated with the presence of nicotine in the eye and if adherence of nicotine on the CL can enhance these effects. A better understanding of the interaction between nicotine and CL materials could offer insights to explain this risk associated with smoking. The aim of this work was to compare the affinity of nicotine to different soft CL materials. CLs from FDA groups I, II, IV, and V were incubated in a 2-mM nicotine solution for 24 h and then in a 0.9% saline solution for the next 24 h. The amount of absorbed and released nicotine per CL was deduced as a function of time (t) by ultraviolet (UV) spectrophotometry and normalised to the mass of the hydrated CL. The data were described by the equation y = b -a t-1, where a and b are constants, and b represents the mass reached at the plateau after ~ 10 min of exposure. Groups IV and V displayed the highest (0.80 ± 0.09 µg) and lowest (0.27 ± 0.08 µg) nicotine absorption per mg of hydrated CL, respectively. The CL affinity for nicotine could be ascribed to the interaction between the positive charge of nicotine pyrrolidine nitrogen and the negative charges of the CLs, especially for the ionic IV group.
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Affiliation(s)
- Federica Miglio
- University of Milano Bicocca, Materials Science Department, via R. Cozzi 55, I-20125 Milan, Italy; University of Milano Bicocca, COMiB Research Center, via R. Cozzi 55, I-20125 Milan, Italy
| | - Erika Ponzini
- University of Milano Bicocca, Materials Science Department, via R. Cozzi 55, I-20125 Milan, Italy; University of Milano Bicocca, COMiB Research Center, via R. Cozzi 55, I-20125 Milan, Italy.
| | - Fabrizio Zeri
- University of Milano Bicocca, Materials Science Department, via R. Cozzi 55, I-20125 Milan, Italy; University of Milano Bicocca, COMiB Research Center, via R. Cozzi 55, I-20125 Milan, Italy; School of Life & Health Sciences, Aston University, Aston Triangle, Birmingham B4 7ET, UK
| | - Alessandro Borghesi
- University of Milano Bicocca, Materials Science Department, via R. Cozzi 55, I-20125 Milan, Italy; University of Milano Bicocca, COMiB Research Center, via R. Cozzi 55, I-20125 Milan, Italy
| | - Silvia Tavazzi
- University of Milano Bicocca, Materials Science Department, via R. Cozzi 55, I-20125 Milan, Italy; University of Milano Bicocca, COMiB Research Center, via R. Cozzi 55, I-20125 Milan, Italy
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