Surface Properties of Squalene/Meibum Films and NMR Confirmation of Squalene in Tears
Squalene (SQ) possesses a wide range of pharmacological activities (antioxidant, drug carrier, detoxifier, hydrating, emollient) that can be of benefit to the ocular surface. It can come in contact with human meibum (hMGS; the most abundant component of the tear film lipid layer) as an endogenous t...
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MDPI AG
2015-09-01
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| Series: | International Journal of Molecular Sciences |
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| Online Access: | http://www.mdpi.com/1422-0067/16/9/21813 |
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| author | Slavyana Ivanova Vesselin Tonchev Norihiko Yokoi Marta C. Yappert Douglas Borchman Georgi As. Georgiev |
| author_facet | Slavyana Ivanova Vesselin Tonchev Norihiko Yokoi Marta C. Yappert Douglas Borchman Georgi As. Georgiev |
| author_sort | Slavyana Ivanova |
| collection | DOAJ |
| description | Squalene (SQ) possesses a wide range of pharmacological activities (antioxidant, drug carrier, detoxifier, hydrating, emollient) that can be of benefit to the ocular surface. It can come in contact with human meibum (hMGS; the most abundant component of the tear film lipid layer) as an endogenous tear lipid or from exogenous sources as eyelid sebum or pharmaceuticals. The aims of this study were to determine (i) if SQ is in tear lipids and (ii) its influence on the surface properties of hMGS films. Heteronuclear single quantum correlation NMR confirmed 7 mol % SQ in Schirmer’s strips extracts. The properties of SQ/hMGS pseudo-binary films at the air/water interface were studied with Langmuir surface balance, stress-relaxation dilatational rheology and Brewster angle microscopy. SQ does not possess surfactant properties. When mixed with hMGS squalene (i) localized over the layers’ thinner regions and (ii) did not affect the film pressure at high compression. Therefore, tear SQ is unlikely to instigate dry eye, and SQ can be used as a safe and “inert” ingredient in formulations to protect against dry eye. The layering of SQ over the thinner film regions in addition to its pharmacological properties could contribute to the protection of the ocular surface. |
| first_indexed | 2024-04-12T19:41:54Z |
| format | Article |
| id | doaj.art-34dc73460fed4e508e7e57ae7b8b105b |
| institution | Directory Open Access Journal |
| issn | 1422-0067 |
| language | English |
| last_indexed | 2024-04-12T19:41:54Z |
| publishDate | 2015-09-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | International Journal of Molecular Sciences |
| spelling | doaj.art-34dc73460fed4e508e7e57ae7b8b105b2022-12-22T03:19:04ZengMDPI AGInternational Journal of Molecular Sciences1422-00672015-09-01169218132183110.3390/ijms160921813ijms160921813Surface Properties of Squalene/Meibum Films and NMR Confirmation of Squalene in TearsSlavyana Ivanova0Vesselin Tonchev1Norihiko Yokoi2Marta C. Yappert3Douglas Borchman4Georgi As. Georgiev5Department of Biochemistry, Faculty of Biology, St. Kliment Ohridski University of Sofia, 1164 Sofia, BulgariaInstitute of Physical Chemistry "R. Kaischew"-BAS, Phase Formation, Crystals and Amorphous Materials Department, 1113 Sofia, BulgariaDepartment of Ophthalmology, Kyoto Prefectural University of Medicine, Kyoto 602-0841, JapanDepartment of Chemistry, University of Louisville, Louisville, KY 40202, USADepartment of Ophthalmology and Visual Sciences, University of Louisville, Louisville, KY 40202, USADepartment of Biochemistry, Faculty of Biology, St. Kliment Ohridski University of Sofia, 1164 Sofia, BulgariaSqualene (SQ) possesses a wide range of pharmacological activities (antioxidant, drug carrier, detoxifier, hydrating, emollient) that can be of benefit to the ocular surface. It can come in contact with human meibum (hMGS; the most abundant component of the tear film lipid layer) as an endogenous tear lipid or from exogenous sources as eyelid sebum or pharmaceuticals. The aims of this study were to determine (i) if SQ is in tear lipids and (ii) its influence on the surface properties of hMGS films. Heteronuclear single quantum correlation NMR confirmed 7 mol % SQ in Schirmer’s strips extracts. The properties of SQ/hMGS pseudo-binary films at the air/water interface were studied with Langmuir surface balance, stress-relaxation dilatational rheology and Brewster angle microscopy. SQ does not possess surfactant properties. When mixed with hMGS squalene (i) localized over the layers’ thinner regions and (ii) did not affect the film pressure at high compression. Therefore, tear SQ is unlikely to instigate dry eye, and SQ can be used as a safe and “inert” ingredient in formulations to protect against dry eye. The layering of SQ over the thinner film regions in addition to its pharmacological properties could contribute to the protection of the ocular surface.http://www.mdpi.com/1422-0067/16/9/21813Langmuir troughmeibumNMRsebumsqualenetear film |
| spellingShingle | Slavyana Ivanova Vesselin Tonchev Norihiko Yokoi Marta C. Yappert Douglas Borchman Georgi As. Georgiev Surface Properties of Squalene/Meibum Films and NMR Confirmation of Squalene in Tears International Journal of Molecular Sciences Langmuir trough meibum NMR sebum squalene tear film |
| title | Surface Properties of Squalene/Meibum Films and NMR Confirmation of Squalene in Tears |
| title_full | Surface Properties of Squalene/Meibum Films and NMR Confirmation of Squalene in Tears |
| title_fullStr | Surface Properties of Squalene/Meibum Films and NMR Confirmation of Squalene in Tears |
| title_full_unstemmed | Surface Properties of Squalene/Meibum Films and NMR Confirmation of Squalene in Tears |
| title_short | Surface Properties of Squalene/Meibum Films and NMR Confirmation of Squalene in Tears |
| title_sort | surface properties of squalene meibum films and nmr confirmation of squalene in tears |
| topic | Langmuir trough meibum NMR sebum squalene tear film |
| url | http://www.mdpi.com/1422-0067/16/9/21813 |
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