Study on the High Functional Contact Lens Material with Superior Oxygen Transmissibility and Antibacterial Properties.

The silicone monomer (SiH2) used in this study contains acrylate monomer, DMA (n,n-dimethylacrylamide). For the polymerization, PtOEP (platinum octaethylporphyrin) was added to the synthesized silicone, DMA (n,n-dimethyl acrylamide), HPMA (hydroxy propyl methacrylate), PEGMEMA [poly(ethylene glycol) methyl ether methylacrylate], EGDMA (ethylene glycol dimethacrylate) and the initiator AIBN (azobisisobutyronitrile) with various concentrations. Using the polymer produced through the thermal polymerization process, the optical and physical characteristics of high performance silicone hydrogel lenses were measured. The water content of sample containing PtOEP was in the range of 65.21∼66.56%. And also, oxygen permeability (Dk) of sample containing PtOEP was in the range of 30.20∼30.85 × 10-11 cm²/sec × mlO2/ml × mmHg. In case of the sample with nanoparticle, the oxygen permeability was higher than that of Ref. sample without nanoparticle. Silicone hydrogel monomer containing PtOEP was expected to be used usefully as a material for red tinted chromagen optical lens with high oxygen permeability for color amblyopia.

Photopolymerization and Characterization of Dental Resin Cement Containing Nano Material.

In this study, to manufacture dental resin cement, Bis-GMA was used as a major ingredient, TEGDMA was used as a diluent, and camphoroquinone was used as a photoinitiator. Nanodiamonds were added to increase the bonding strength. After mixing Bis-GMA, HPMA, TEGDMA, BHT, BPO, and camphoroquinone (photoinitiator), nanodiamonds were added at a ratio of 2-3%, and polymerization was done after stirring for 24 hours. Photopolymerization was also carried out with Dentmate (LWDEX WL-090) by irradiation at a 440-480 nm wavelength and at about 1000 mW/cm2 intensity for about 40 seconds. As a result of the SEM measurement for the surface analysis, the nanodiamonds were found to have been evenly distributed at 80∼100 nm sizes. The physical properties of each combination were also evaluated to analyze the functionality of the prepared resin cement and as a result, the cultured cells (L929) in all the combinations (Ref., ND-1, and ND-2) had no cytotoxicity. Also the mean shear bond strengths of the control group using commercial resin cement was the range of 5.87∼6.72 MPa. And also, the mean flexural strength was about 94 MPa. These results indicate that the resin cement that was manufactured in this study will have no clinical problem when commercialized for dental practice.

Preparation and Characterization of Novel Dental Material with High Shear Bond Strength.

HPMA (hydroxypropyl methacrylate) and Bis-GMA (bisphenol A glycerolate dimethacrylate), the main ingredients, and styrene, TEGDMA (triethylene glycol dimethacrylate), BPO (benzoyl peroxide) and camphoroquinone, the photo-initiators, and BHT (butylated hydroxytoluene), the photocatalyst were mixed by different ratios and stirred to investigate the compatibility of dental materials with photoinitiators. The degree of polymerization was checked and determination of the most ideal ratio for photopolymerization was followed by establishing the basic combination of styrene, HPMA, Bis-GMA, BHT, TEGDMA and HEMA. The mixture made in accordance to the predetermined ratio was stirred for 24 hours and was polymerized at a wavelength of 440 to 480 nm for 40 secs. The physical properties of each combination were also evaluated to analyze the functionality of the prepared resin cement. And also, the cytotoxicity of the samples was tested, and as a result, the cell lysis rate was 0% in negative control and 100% in positive control and 0% in S-1 combination which indicates that it does not possess cytotoxicity against cultured cells. It is considered suitable for commercializing and will be highly applicable as high quality dental resin cement.

High functional nano materials for ophthalmic lenses containing silicon 2,3-naphthalocyanine bis(trihexylsilyloxide) and silicon 2,9,16,23-tetra-tert-butyl-29H31 H-phthalocyanine dihydroxide.

High functional ophthalmic lens materials, poly(HEMA-co-GMA)s were prepared by the copolymerization of HEMA, MMA, NVP, EDGMA and GMA in the presence of SiNc [silicon 2,3-naphthalocyanine bis(trihexylsilyloxide)] and SiPc (silicon 2,9,16,23-tetra-tert-butyl-29H31H-phthalocyanine dihydroxyde). Also, the physical and optical characteristics of the produced polymers were analyzed to investigate UV-blocking capabilities of these functional ophthalmic dyes and their applicability as materials for colored hydrogel contact lenses. For G_SN samples to which GMA was added to the Ref._SN combination, the transmittance for visible ray, UV-B and UV-A was in the range of 86.0-89.4%, 63.0-67.6% and 62.5-66.0% respectively. Also, for G_SP samples, the transmittance for visible ray, UV-B and UV-A was in the range of 85.2-87.0%, 70.0-72.6 and 68.0-70.2% respectively. The measurement of the spectral transmittance showed that both SiNc and SiPc absorbed a small amount of UV light, but the absorption pattern for UV light differed for each material. Based on the results, the addition of SiNc and SiPc to ophthalmic polymer materials can be used for various purposes in colored ophthalmic lens that are capable of offering protection from UV and infrared light without significant change of the physical properties.

Effects of Ag/Pt nanoparticles on the physical properties of copolymers containing 2-fluoro-5-methylanisole.

The ophthalmic materials must satisfy the optical requirements, physical and chemical stability and fulfill biological requirements, such as biocompatibility to be used in hydrogel ophthalmic lenses. Polymeric materials for hydrogel lenses were prepared by the copolymerization of HEMA, NVP, MMA, EGDMA and FMA in the presence of antibacterial Ag and Pt nanoparticles and also the effect of these copolymers containing nanoparticles on oxygen transmissibility was then investigated. The combination where AgNPs were added produced a light-yellowish colored transparent ophthalmic lens. The copolymers containing Ag and Pt nanoparticles did not have significant impact on the water content and refractive index of the hydrogel contact lens, but the Ag/Pt nanoparticles reduced oxygen permeability to a certain extent. Furthermore, the spectral transmittance significantly decreased. The additive, 2-fluoro-5-methylanisole, did not effect significantly on the physical properties of the polymer, but it was able to block UV light to a certain extent. The water content and oxygen permeability slightly increased as the amount of FMAs increased.

Ophthalmic application of poly(HEMA)s containing nanoparticles and dimethylacrylamide.

High functional ophthalmic lens materials, poly(HEMA-co-MMA)s were prepared by the copolymerization of HEMA, MMA, MA, EDGMA, and N,N-dimethylacrylamide in the presence of platinum nanoparticles with antimicrobial properties. The hydrophilic monomer N,N-dimethylacrylamide has excellent biocompatibility and oxygen transmissibility. The combination where platinum nanoparticles were added produced a colorless transparent lens. The water contents were in the range of 36.68-44.08% and the refractive index was measured to be in the range of 1.424-1.436. Meanwhile, the oxygen transmissibility ranged from 11.13 x 10(-11) to 17.63 x 10(-11) (cm2/sec) (mlO2/ml x mm Hg) increased with increasing the addition ratio of N,N-dimethylacrylamide. The physical properties measurements of the produced polymers showed that the nanoparticles did not show significant effect on the water content and refractive index of the hydrogel contact lens, but the materials effected to reduce oxygen permeability to a certain extent. The copolymers have excellent oxygen permeability, indicating that the material can be used to fabricate hydrogel contact lenses with high oxygen transmissibility.

Polyhedral Oligomeric Silsesquioxane Based Silicone Ophthalmic Contact Lens Material Containing Neodymium Nanoparticles.

This research was conducted to analyze the compatibility of used monomers and produce the high functional POSS-based ophthalmic polymer containing silicone monomers and neodymium nanoparticle. Synthesized silicone polymer (SiD), trimethylsilylmethacrylate (TSMA), N-vinyl-2-pyrrolidone (NVP) and neodymium nanoparticles were used as additives for the basic combination of polyhedral oligomeric silsesquioxane (POSS), and methyl methacrylate (DMA). And also, the materials were copolymerized with ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent, azobisisobutyronitrile (AIBN) as the initiator. It is judged that the POSS-co-NVP polymer is optically good and thus have good compatibility. Especially copolymerization with TSMA showed high oxygen permeability, but with SID considered to be more stable judging by lens shape. Physical properties shows that the neodymium nanoparticle increases the wettability while maintaining water content. These materials are considered to make synergy effect each other, so it can be used in functional hydrogel ophthalmic lenses.

Preparation and Analysis of Functional Silicone Hydrogel Lenses Containing ZrO2 and Antimony Tin Oxide Nanoparticles.

This study prepared silicone hydrogel ophthalmic lenses using 2-hydroxyethylmethacrylate (HEMA), synthesized silicone monomer (SID), dimethylarsinic acid (DMA), N-hydroxyethyl acrylamide (HEA), ethylene glycol dimethacrylate (a crosslinking agent, EGDMA), and azobisisobutyronitrile (an initiator, AIBN). Also, Zirconium oxide (ZrO2), antimony tin oxide (ATO) nanoparticles were added to the silicone hydrogel material to analyze the characteristics of the nanoparticles. The mixture was heated at 130 °C for 2 hours to produce the ophthalmic contact lens by cast mould method. As a result, the manufactured silicone hydrogel lens was prepared having high oxygen permeability and tensile strength while satisfying the basic requirements of ophthalmic hydrogel lens materials. Also, the addition of ZrO2 NPs increased tensile strength of the manufactured lens, and ATO NPs were found to improve wettability. Therefore, ZrO2 and ATO nanoparticles can be used effectively as additives for functional ophthalmic silicone hydrogel lenses.

Study on Dispersant and Surface Analysis of Ophthalmic Lens Materials Containing Carbon Nanotubes.

In this study, two types of carbon nanotubes were used as ophthalmic material, and hydrogel contact lenses were polymerized by adding two types of dispersants to effectively exert the functions of carbon nanotubes. The physical properties and surfaces of the ophthalmic hydrogel lenses prepared to confirm the functionality as a dispersant were compared and analyzed to find the utility as an ophthalmic lens material. For the polymerization, single-walled carbon nanotubes (SWCNTs), single-walled carbon nanotubes carboxylic acid functionalized (SWCCNTs), 2-hydroxyethyl methacrylate (HEMA), ethylene glycol dimethacrylate (EGDMA, a crosslinking agent), and azobisisobutyronitrile (AIBN, an initiator) was used. In addition, as a dispersant, PVP (polyvinylpyrrolidone) and BYK-111 were copolymerized. As a result of this study, PVP increased the water content and decreased refractive index regardless of the type of carbon, whereas BYK-111 did not show a significant difference in basic properties. Also, PVP gradually decreased breaking strength, while BYK-111 gradually increased breaking strength. BYK-111 effectively exerted the function of carbon nanotubes, and it was confirmed whether it was dispersed through TEM. Therefore, if carbon nanotubes are used as ophthalmic materials by utilizing BYK-111, it considered to be used as functional ophthalmic lens materials.