• Journal of the Korean Chemical Society
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• v.64 no.2
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• pp.67-73
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• 2020

The study aimed to investigate in vitro lipid deposition of oleic acid, oleic acid methyl ester and cholesterol on a daily disposable (1-day lenses) and 3-days lenses over 3 days and changes of optical characteristics is also investigated. Artificial tear solutions were prepared to simulate actual tear compositions. Two types of contact lenses (1-day lenses (Senofilcon A) and 3-days lenses (silicone tripolymer)) were soaked in the artificial tear solutions within an incubator at 37 ℃ with 150 rpm for 8, 16, 24 hours. Lipid deposition (oleic acid, oleic acid methyl ester and cholesterol) were measured using high performance liquid chromatography (HPLC) instrument. In addition, measurements of oxygen transmissibility, light transmittance and observation of lens surface were conducted. The amount of lipid deposition on the 1-day lenses were 127.55 ㎍/lens for Day 1, 302.96 ㎍/lens, for Day 2, and 353.30 ㎍/lens for Day 3. The 3-days lenses were 46.22 ㎍/lens for Day 1, 66.07 ㎍/lens for Day 2, and 67.45 ㎍/lens for Day 3. Oxygen transmissibility were 81×10^-9(cm/sec)(ml O₂/ml×mmHg)(Baseline) and 48×10^-9(cm/sec)(ml O₂/ml×mmHg) (Day 3) for the 1-day lenses, it were 13.23×10^-9(cm/sec)(ml O₂/ml×mmHg)(Baseline) and 9.6×10^-9(cm/sec)(ml O₂/ml×mmHg) (Day 3) for the 3-days lenses. Transmittance of each lenses were 97.21% (Baseline) and 94.25% (Day 3) for the 1-day lenses, 97.65% (Baseline) and 95.15% (Day 3) for the 3-days lenses. Observation of surface deposition indicated greatest deposition for the 3-days lenses type on Day 3. Lipid deposition for both lens types increased by day and was greater for the 1-day lenses type. Surface deposition appeared to differ as it was greatest for the 3 days lens type, which may suggest other deposits such as protein may be present.

• Journal of the Korean Chemical Society
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• v.54 no.1
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• pp.99-104
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• 2010

Platinum nanoparticles were added to a mixture of HEMA (2-hydroxyethyl methacrylate), NVP (N-vinyl pyrrolidone) and MMA (methyl methacrylate) in a mould at various concentrations. The resulting mixture was copolymerized by heating at $70^{\circ}C$ for 40 min, $80^{\circ}C$ for 40 min, and $100^{\circ}C$ for 40 min, respectively. The physical properties of contact lens were then measured. The oxygen transmissibility of $9{\sim}15{\times}10^{-9}$ cm/s mL $O_2$/mL ${\times}$ mmHg, water content of 34.22~35.52%, refractive index of 1.432~1.435, visible transmittance of 88.3~91.2% and tensile strength of 0.141~0.152 kgf were obtained. The addition of platinum nanoparticles to the polymer allowed the contact lens to have various colors without artificial coloring agents. The polymer materials satisfied the physical properties required to produce contact lenses, making the material suitable to be applied as a functional material for ophthalmological purposes.

• Journal of the Korean Chemical Society
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• v.54 no.2
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• pp.222-227
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• 2010

This study added Au colloid in martial of conventional contact lens in various concentrations and copolymerized by heating at $70^{\circ}C$ for 40 minutes, $80^{\circ}C$ for 40 minutes, and finally, $100^{\circ}C$ for 40 minutes. Using the polymer produced through the copolymerization process, we have produced a contact lens and measured the physical characteristics which showed oxygen transmissibility of $9{\sim}12{\times}10^{-9}$ cm/s mL $O_2$/mL ${\times}$ mmHg, water content of 27.84% ~ 32.17%, refractive index of 1.432 ~ 1.443, visible transmittance of 83.2% ~ 89.5% and tensile strength of 0.141 kgf ~ 0.152 kgf. The polymer satisfied the physical properties required to produce contact lenses. Also, we judged that the polymer is suitable to be applied as a functional material for ophthalmological purposes.