Accelerated hydrolytic and ultraviolet aging studies on SI-18NB and SI-20NB silicone lenses

Intraocular lenses (IOLs) are worldwide used for cataract surgery. Mostly made of acrylate polymers, they can lead to an unexpected biocompatibility reaction such as posterior capsular opacification (PCO). Acrylate polymers suffer from both oxidative and heat/thermal aging that affect their properties. We examined the stability of four currently available acrylic IOLs, three hydrophobic and one amphiphilic, under artificial aging that simulate intraocular conditions from 2 to 20 years. Released degradation products were detected by reversed‐phase high performance liquid chromatography. Thermal properties were investigated using thermogravimetric analysis, and differential scanning calorimetry measurements. Surface topography was analyzed by atomic force microscopy. The effect on biocompatibility was estimated with protein sorption of the aged lenses. Both surface and thermal properties changed under aging. Surface roughness of implants increased under aging in a kinetic in two steps. The aging also changed the polymer structure. These changes lead to a variable release of degradation products according to the chemical design of the copolymer. Glass temperature transition (Tg) and thermal degradation stability also suffered from aging. The aging has led to significant changes in protein sorption affinity to IOL surfaces. For pure hydrophobic acrylic copolymer, stability was higher for copolymers containing at least one fluoro methacrylate. The amphiphilic polymer appeared to have a time‐dependent aging that can affect the implant flexibility and could impact late biocompatibility reaction and tolerance.

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“…The optical properties were not investigated in this work considering that results have already been published. [29][30][31][32][33][34]…”

Section: Resultsmentioning

confidence: 99%

“…Regarding their integrity, no splits were noted in any case. The optical properties were not investigated in this work considering that results have already been published 29–34 …”

Section: Resultsmentioning

confidence: 99%

Comparative stability of intraocular lenses during 2–20 years of artificial aging, potential effects in terms of biocompatibility

Tortolano

Mrad

Manerlax

et al. 2022

J of Applied Polymer Sci

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“…The permanent character of the IOL implantation requires experimental hydrolytic aging studies equivalent to at least 20 years of in vivo exposure. 28 While found that the aqueous extractables of Teflon-coated IOLs produced no toxic effect to L-929 fibroblasts, as demonstrated, the uptake of neutral red by the viable cells, accelerated hydrolytic aging studies are necessary to assess the long-term resistance of Tefloncoated IOLs to hydrolytic activity. …”

Section: Discussionmentioning

confidence: 99%

Neutral red assay of the cytotoxicity of fluorocarbon-coated polymethylmethacrylate intraocular lenses in vitro

Werner

Legeais

Nagel

et al. 1999

J. Biomed. Mater. Res.

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Polymethylmethacrylate (PMMA) intraocular lenses (IOLs) were coated with Teflon AF, an amorphous, transparent Teflon, to render them highly hydrophobic. Teflon-coated PMMA IOLs were immersed in culture medium for 30 days at 37 degrees C. Four concentrations of the IOL leachables, 2 concentrations of a toxic control (phenol), and complete liquid culture medium (nontoxic control) were incubated for 24 h in a 96-well plate containing confluent L-929 fibroblasts. The cytotoxic effect of each solution on the fibroblasts was quantitatively assessed by measuring the uptake of neutral red by the viable cells. After the extraction of the neutral red using 1% acetic acid-50% ethanol, the optical densities were measured with a microplate reader at 550 nm. Scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to analyze the surfaces of the IOLs. Only the optical densities in the wells containing fibroblasts that had been in contact with the phenol solutions were significantly lower than those in the wells incubated with the nontoxic control solution (p < 0.01). There were no signs of surface alteration by SEM, apart from some crystals on the IOLs. The crystals were composed of Na and Cl, as demonstrated by XPS. Aqueous extractables from the Teflon-coated IOLs produced no cytotoxic effects in the neutral red assay used.

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Transparenzverlust einer Silikon-Hinterkammerlinse im nahen Infrarotbereich

Wetzel¹,

Duncker²

1993

7. Kongreß Der Deutschsprachigen Gesellschaft Für Intraokularlinsen Implantation

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Accelerated hydrolytic and ultraviolet aging studies on SI-18NB and SI-20NB silicone lenses

Cited by 11 publications

References 1 publication

Comparative stability of intraocular lenses during 2–20 years of artificial aging, potential effects in terms of biocompatibility

Comparative stability of intraocular lenses during 2–20 years of artificial aging, potential effects in terms of biocompatibility

Neutral red assay of the cytotoxicity of fluorocarbon-coated polymethylmethacrylate intraocular lenses in vitro

Transparenzverlust einer Silikon-Hinterkammerlinse im nahen Infrarotbereich

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