scholarly journals The Bio-Tribological Effect of Poly-Gamma-Glutamic Acid in the Lysozyme-Ionic Contact Lens System

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 156
Author(s):  
Chen-Ying Su ◽  
Lung-Kun Yeh ◽  
Chi-Chun Lai ◽  
Mihaela Dubuisson ◽  
Yi-Fei Tsao ◽  
...  
Keyword(s):  
Friction Coefficient ◽  
Glutamic Acid ◽  
Contact Lens ◽  
Contact Lenses ◽  
Lens System ◽  
Friction Testing ◽  
Lubricating Property ◽  
Velocity Variations

Feeling comfortable is an important issue for contact lens wearers as contact lenses are worn for an extensive period of time. It has been shown that the in vitro friction coefficient of contact lenses is correlated to the degree of in vivo comfort, thus many studies focus on establishing friction testing methods for investigating the friction coefficient of contact lenses or contact lens care solution. We have previously demonstrated the lubricating property of poly-gamma-glutamic acid (γ-PGA)-containing care solution, and it could reduce the high friction coefficient caused by lysozyme. However, the mechanism of how γ-PGA-containing care solution reduces the lysozyme-induced friction coefficient of contact lenses is unclear. We investigated the bio-tribological effect of γ-PGA on ionic contact lenses in the presence of lysozyme by testing load and velocity variations. The ability to remove lysozyme deposition by γ-PGA and viscosity analysis of γ-PGA-containing care solutions were also investigated to understand the potential mechanism. Our results showed that the friction coefficient of γ-PGA-containing care solution with lysozyme was the lowest in both load and velocity variations, and γ-PGA functions distinctly in the lysozyme-ionic contact lens system. We proposed a model of how γ-PGA could reduce the friction coefficient in these two conditions.

scholarly journals Albumin Acts as a Lubricant on the Surface of Hydrogel and Silicone Hydrogel Contact Lenses

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2051
Author(s):  
Chen-Ying Su ◽  
Lung-Kun Yeh ◽  
Tzu-Wei Fan ◽  
Chi-Chun Lai ◽  
Hsu-Wei Fang
Keyword(s):  
Surface Roughness ◽  
Friction Coefficient ◽  
Contact Lenses ◽  
Albumin Solution ◽  
High Concentration ◽  
Silicone Hydrogel ◽  
Deposition Amount ◽  
Roughness Analysis

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.

In vivo and in vitro application of thin film interferometry to assess contact lens wettability

2018 ◽  
Vol 41 ◽  
pp. S9
Author(s):  
Raied Fagehi ◽  
Ian Pearce ◽  
Katherine Oliver ◽  
Alan Tomlinson
Keyword(s):  
Thin Film ◽  
Contact Lens

Controlled bimatoprost release from graphene oxide laden contact lenses: In vitro and in vivo studies

2021 ◽  
Vol 208 ◽  
pp. 112096 ◽  
Author(s):  
Furqan A. Maulvi ◽  
Parth D. Soni ◽  
Pooja J. Patel ◽  
Ankita R. Desai ◽  
Ditixa T. Desai ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Contact Lenses ◽  
In Vivo Studies

scholarly journals Tannic acid-modified silver nanoparticles enhance anti-Acanthamoeba activity without increasing cytotoxicity of three multipurpose contact lens solutions

2020 ◽  
Author(s):  
Edyta Beata Hendiger ◽  
Marcin Padzik ◽  
Agnieszka Żochowska ◽  
Wanda Baltaza ◽  
Gabriela Olędzka ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Tannic Acid ◽  
Contact Lens ◽  
Contact Lenses ◽  
Colorimetric Assay ◽  
Statistical Significance ◽  
Plant Metabolites ◽  
Contact Lens Solutions ◽  
Preventive Actions

Abstract Background: Free living amoebae of Acanthamoeba genus are cosmopolitan, widely distributed protozoans causing severe, vision-threatening corneal infection known as Acanthamoeba keratitis (AK). Majority of the increasing number of AK cases are associated with contact lenses use. Due to lack of effective therapies against AK, proper eye hygiene and effective contact lenses disinfection are crucial in prevention of this infection. Currently available multipurpose contact lens disinfection systems are not fully effective against Acanthamoeba trophozoites and cysts. There is an urgent need to increase the disinfecting activity of these systems to prevent Acanthamoeba keratitis infections. Synthesized nanoparticles have been recently studied and proposed as a new generation of anti-microbial agents. It is also known that plant metabolites, including tannins, present anti-parasitic activity. The aim of this study was to evaluate the anti-amoebic activity and cytotoxicity of the tannic acid-modified silver nanoparticles (AgTANPs) conjugated with the selected multipurpose contact lens solutions.Methods: The anti-amoebic activity of pure contact lens care solutions and nanoparticles conjugated with contact lens care solutions were examined in vitro by colorimetric assay, based on the oxido-reduction of AlamarBlue. The cytotoxicity assays were performed using a fibroblast HS-5 (ATCC CRL-11882) cell line. The results were statistically analyzed by ANOVA and Student-Newman-Keuls tests using the p<0.05 level of a statistical significance.Results: The obtained results showed that nanoparticles enhanced anti-Acanthamoeba activity of the tested contact lens solutions without increasing their cytotoxicity profile. The activity is enhanced within minimal disinfection time recommended by the manufacturer.Conclusions: The conjugation of the selected contact lens solutions with AgTANPs might be a novel and promising approach as a part of preventive actions of Acanthamoeba keratitis infections among contact lens users.

scholarly journals Novel Poly(vinylpyrrolidone)-Coated Silicone Contact Lenses to Improve Tear Volume During Lens Wear: In Vitro and In Vivo Studies

ACS Omega ◽  
2020 ◽  
Vol 5 (29) ◽  
pp. 18148-18154
Author(s):  
Furqan A. Maulvi ◽  
Pooja J. Patel ◽  
Parth D. Soni ◽  
Ankita R. Desai ◽  
Ditixa T. Desai ◽  
...  
Keyword(s):  
Contact Lenses ◽  
In Vivo Studies ◽  
Lens Wear

scholarly journals Poly-Gamma-Glutamic Acid Functions as an Eective Lubricant with Antimicrobial Activity in Multipurpose Contact Lens Care Solutions

Polymers ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1050 ◽  
Author(s):  
Chen-Ying Su ◽  
Ching-Li Tseng ◽  
Shu-Hsuan Wu ◽  
Bo-Wu Shih ◽  
Yi-Zhou Chen ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Glutamic Acid ◽  
Chlorine Dioxide ◽  
Contact Lens ◽  
Synergetic Effect ◽  
Main Ingredient ◽  
Functional Polymer ◽  
Multiple Functions ◽  
Lubricating Property ◽  
And Storage

In order to perform the multiple functions of disinfection, cleansing, and storage, preservatives are often added to contact lens care solutions. The disadvantage of adding preservatives is that this often causes various eye conditions. However, lens care solutions would not be able to disinfect in the absence of such preservatives. In addition, comfort is an important issue for contact lens wearers due to the long periods of time they are worn. It has been shown that lower friction coefficients are correlated with increased comfort. We have previously developed a multipurpose contact lens care solution in which poly-gamma-glutamic acid (γ-PGA) was the main ingredient. In this study, we investigated the antimicrobial activity and lubricating property of our care solution. We showed that there was a synergetic effect of γ-PGA and chlorine dioxide on antimicrobial activity. We also demonstrated that γ-PGA functioned as a lubricating agent. Our results provided evidence of γ-PGA acting as a multi-functional polymer that could be applied in contact lens care solutions.

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