Correlation Analysis of Surface and Physical Properties of Ophthalmic Lenses Containing Nanoparticles.

Since contact lenses directly contact the cornea, the surface roughness of the lens may cause various side effects. In addition, gold nanoparticles can realize a variety of colors and characteristics depending on their shape and size. In this study, the surface roughness of tinted lenses containing gold nanoparticles of various sizes was analyzed using atomic force microscopy (AFM) at aspect ratio(surface to volume ratio) ranging from 1:1 to 1:10. The characteristics of the lenses were then confirmed. As a result, tinted lenses with different colors depending on the size of the gold nanoparticles were manufactured. The surface roughness of the lens decreased with increasing size of the gold nanoparticles. However, at aspect ratio of 1:10, increase in surface roughness was observed. In addition, it was confirmed that the wettability and antibacterial properties of the lens had the same effect according to the average surface roughness value. Therefore, it was confirmed that the addition of gold nanoparticles reduced the surface roughness of the lens, which had a great effect on properties such as wettability and antimicrobial properties of the lens. The produced copolymer controls the surface roughness of the lens, and thus it is judged that it can be used as a material for various ophthalmology applications.

Ophthalmic Hydrogel Contact Lens Material Containing Magnesium Oxide Nanoparticles and 3-(Trifluoromethyl)styrene for Biomedical Application.

This research was conducted for the synthesis and application of ophthalmic lens materials with improved oxygen permeability and durability. Polyvinylpyrrolidone (PVP), N-vinyl-2-pyrrolidone (NVP), 3-(trifluoromethyl)styrene (3-TFMSt), and magnesium oxide nanoparticles were used as additives for the basic combination of 2-hydroxyethyl methacrylate (HEMA). Additionally, the materials were copolymerized with ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent and azobisisobutyronitrile (AIBN) as the initiator. The addition of magnesium oxide nanoparticles was found to increase the tensile strength from 0.0631 to 0.0842 kgf/mm2. Copolymerization with a small amount of 3-TFMSt of about 1% increased the tensile strength to 0.1506 kgf/mm2 and the oxygen permeability from 6.00 to 9.64 (cm2/s)∙(mLO2/mL·mmHg)∙10-11. The contact lens material produced using N-vinyl-2-pyrrolidone and magnesium oxide nanoparticles as additives satisfied the basic physical properties required for hydrogel contact lenses and is expected to be used usefully as a material for fabricating high-performance hydrogel lenses.

Development of Functional Ophthalmic Materials Using Natural Materials and Gold Nanoparticles.

Ginsenoside, known as a natural substance, is a saponin component in ginseng and has various effects, such as antibacterial, antioxidant, and anti-inflammatory effects. In addition, gold nanoparticles can realize various optical and physical properties according to particle size and shape. For polymer polymerization, ginsenoside and gold nanoparticles were used as additives and copolymerized with a basic silicone hydrogel material. As gold nanoparticles, spherical and rod-shaped particles were used, and basic physical properties, such as water content, refractive index, and wettability of the prepared ophthalmic lenses, were measured. As a result of measuring the physical properties of the resulting polymer, it was found that the contact angle decreased by about 1.6% to 83.1% as the addition ratio of ginsenoside increased. In addition, as the addition ratio of metal nanoparticles increased, the refractive index was found to increase regardless of the shape of the nanoparticles. In addition, in the case of water content, the spherical shape gradually decreased according to the addition ratio, while the rod shape gradually increased according to the addition ratio. Therefore, it was found that the addition of ginsenoside, known as a saponin-based natural substance, has excellent wettability, and gold nanoparticles with different shapes have different properties. Thus, it is judged that the resulting copolymer can be utilized as a variety of highly functional ophthalmic polymer materials with high refractive index and high wettability.

Poly (Ethylene Glycol) Methyl Ether Methacrylate-Based Hydrogel and Cerium(IV) Oxide Nanoparticles as Ophthalmic Lens Material.

The functional hydrogel lens containing 2-hydroxyethylmethacrylate (HEMA) was manufactured by thermal polymerization. The physical properties of the produced hydrogel lens were measured and analyzed. In this study, HEMA, ethylene glycol dimethacrylate (EGDMA), and azobisisobutyronitrile (AIBN) were used for thermal copolymerization. Additionally, poly (ethylene glycol) methyl ether methacrylate (PEGMEMA), 3-(Triethoxysilyl) propyl isocyanate (TEPI), and cerium(Ⅳ) oxide nanoparticles were used as additives to make a functional hydrogel lens. The mixture was heated at 100 °C for 90 min to produce the hydrogel ophthalmic lens by the cast mold method. The resulting physical properties showed that the water content and refractive index of the sample were in the ranges of 38.06~42.11% and 1.426~1.436, respectively. The addition of cerium oxide nanoparticles lowered the contact angle and allowed the hydrogel lens to block UV light. The tensile strength was also improved by 52.13% through cerium oxide nanoparticles, and up to 123.4% by using TEPI. Based on the results of this study, the produced ophthalmic lens is suitable for durable, UV-blocking high-performance lenses.

Characterization of Biocompatible Hydrogel Lenses Using Methacrylic Acid with Neodymium Oxide Nanoparticles.

We prepared hydrogel contact lenses containing nanoparticles of neodymium oxide and methacrylic acid (MA) to investigate their effect on the physical and chemical properties of the lens. Neodymium oxide nanoparticles improved the tensile strength without affecting wettability. The tensile strength, wettability, and light transmittance were all increased when MA was added in a specific ratio. To confirm the safety of the newly used nanoparticles, test on absorbance, eluate, and pH change were conducted and it was found that the safety level was satisfactory. In conclusion, it was confirmed that durable contact lenses can be manufactured with neodymium oxide nanoparticles, and most of the basic elements of the lens such as transparency, strength, and wettability could be improved using MA, which is a hydrophilic material. It is believed that the study will be helpful as part of basic research to use new materials.

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.

Copolymerization of Acrylic Monomers and Silane Group Containing Titanium Carbide Nanoparticles for Application to Ophthalmic Lens Materials.

This research was conducted to synthesis and application for high oxygen permeable ophthalmic lens materials. 2-(Trimethylsiloxy)ethyl methacrylate (2T), 3-[Tris(trimethylsiloxy)silyl]propyl methacrylate (3T), [(1,1-Dimethyl-2-propynyl)oxy]trimethylsilane (TMS), Poly(ethylene glycol) methyl ether methacrylate (PEGMA), N-vinyl-2-pyrrolidone (NVP) and titanium carbide nanoparticles were used as additives for the basic combination of synthesized silicone monomer (SiD) and N,N-Dimethylacetamide (DMA). And also, the materials were copolymerized with ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent, azobisisobutyronitrile (AIBN) as the initiator. The copolymerization with a small amount of silane of about 1% increased the oxygen permeability to 30.3˜33.52(cm²/sec)·(mlO2/ml·mm Hg)·10-11, and in particular, the addition of titanium carbide nanoparticles was found to increase to 46.38 (cm²/sec)·(ml O2/ml·mm Hg)·10-11. Surface modification was possible with various wetting agents. Especially, simultaneous use with titanium carbide nanoparticles increased 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.

Effects on the Physical Properties of Ophthalmic Hydrogels Containing 4-Chlorostyrene and Cerium Oxide Nanoparticles with Ultraviolet Blocking Ability.

The optical, physical and polymerization property of hydrogel ophthalmic lenses made by cerium nanoparticles containing 4-chlorostyrene as a base hydrogel material were analyzed. Cerium oxide nanoparticles were used as additive. And HEMA, 4-chlorostyrene and a cross-linker EGDMA were copolymerized in the presence of AIBN as an initiator. Also, the polymerization property such as TGA and absorbance of the prepared lens were measured. Measurement of the polymerization characteristics of the copolymerized material showed that TGA was found that the addition of cerium oxide increased thermal stability. The physical properties of the basic lenses were totally satisfied and breaking strength gradually increased with the addition amount of 4-Chlorostyrene. Cerium nanoparticles are considered to satisfy the basic requirements of hydrogel lenses and UV-blocking amount gradually increased according to the addition ratio of cerium oxide nanoparticles without affecting the basic physical properties. Therefore, these materials can be used effectively as additives for ophthalmic hydrogel lenses.

Characterization and Compatibility of High Oxygen Permeable Ophthalmic Biomaterial Containing Silane with Cobalt Oxide Nanoparticles.

This research is conducted to analyze the compatibility of used monomers and produce the high functional hydrogel ophthalmic polymer containing silane and nanoparticles. Vinyltrimethoxysilane (VTMS) and cobalt oxide nanoparticles are used as additives for the basic combination of silicone monomer (Sil-H) and methyl methacrylate (MMA). And also, the materials are copolymerized with ethylene glycol dimethacrylate (EGDMA) as the cross-linking agent, photo polymerization initiator (2H2M) as the initiator. It is judged that the lenses of all combinations are optically excellent and thus have good compatibility. Measurement of the optical and physical characteristics of the manufactured hydrophilic ophthalmic polymer are different in each case. Especially VTMS with cobalt oxide nanoparticle increases the oxygen permeability by the addition of cobalt nanoparticles. These materials are considered to make synergy effect each other, so it can be used in functional hydrogel ophthalmic lenses.

Effect of Metal Oxide Nanoparticles on Silicone-Acrylate Copolymer Containing 1,3-Bis(3-aminopropyl)tetramethyldisiloxane.

The silicone monomer used in this study contains acrylate group to prepare the hydrophilic polymer. For the polymerization, TMDS (1,3-Bis(3-aminopropyl)tetramethyldisiloxane) was added to the mixture containing synthesized silicone, DMA (N,N-dimethyl acrylamide), HEMA (2-Hydroxyethyl methacrylate), EGDMA (ethylene glycol dimethacrylate) and the initiator AIBN (azobisisobutyronitrile) with various concentrations. To make the functional hydrogel lens, metal oxide (Chromium oxide and Cobalt iron oxide) nanoparticles were used as additives. Using the polymer produced through the thermal polymerization process, the optical and physical characteristics of produced silicone hydrogel lenses were measured. The water content of sample was in the range of 63.70~69.08%, refractive index 1.3769~1.3880, contact angle 60.02~85.28°, and oxygen permeability (Dk) 24.79~37.92 × 10-11 (cm²/sec) (mlO²/mlmmHg). In case of the hydrogel sample with nanoparticles, the oxygen permeability value was increased with amount of nanoparticles. Silicone hydrogel monomer containing metal oxide nanoparticles were expected to be used usefully as a material for green tinted optical lens with high oxygen permeability.

Physical Properties of High Functional Contact Lenses with Hydrophilic Substance and Graphene Oxide Nanocolloids.

The purpose of this experiment is to evaluate the physical properties of contact lenses made by adding hydrophilic Hyaluronic acid (HA) and Methacrylic acid (MA) as additives and Graphene oxide nanocolloids. As a contact lens, AIBN (Azobisisobutyronitrile) was used as an initiator with HEMA (2-hydroxy methyl methacrylate) and EGDMA (ethylene glycol dimethacrylate) as a cross-linker. Hyaluronic acid (HA) and methacrylic acid (MA) were added at 5%, respectively. Graphene oxide nanocolloids were added at 0.1%, 0.3% and 0.5%, respectively. Each prepared contact lens was hydrated in 99% NaCl saline solution for 24 hours. And the basic physical properties of contact lenses were evaluated and compared. The refractive index of the sample with hyaluronic acid and MA added was 1.4390, which was not significantly different from that of the basic combination contact lens sample. When Graphene oxide nanocolloids, a nanomaterial, were added, the refractive index decreased with increasing amount of Graphene oxide nanocolloids from 1.4209 to 13959. In the case of water content, the sample with 5% Hyaluronic acid and MA added slightly increased to 41.01%. In the case of Graphene oxide nanocolloids added, 48.76%~53.56% of Graphene oxide nanocolloids were added. Especially, it was observed that the water content increased sharply in the 0.1% sample of Graphene oxide nanocolloids. When the amount of graphene oxide nanocolloids added to the contact lens material was increased, the refractive index, which is a basic physical property, gradually decreased as the contact lens material was added together with Hyaluronic acid, MA, and Graphene oxide nanocolloids added as a nanomaterial. The water content tended to increase gradually. Therefore, the combination of Graphene oxide and hydrophilicmaterials shows a synergistic effect of physical properties, which is considered to be suitable as a material for contact lenses.

Preparation and Characterization of High Functional Ophthalmic Lens Material Containing Acrylic Formation Isocyanate Group with Carbon Nanoparticles.

This research was conducted to produce the high functional hydrogel ophthalmic lens containing iso-cyanate group and nanoparticles. IsoMA (2-Isocyanatoethyl methacrylate) and carbon nanoparticles were used as additives for the basic combination including HEMA (2-hydroxyethyl methacrylate), MA (methacrylic acid), and MMA (methyl methacrylate). And also, the materials were copolymerized with EGDMA (ethylene glycol dimethacrylate) as the cross-linking agent and AIBN (azobisisobutyronitrile) as the initiator. Measurement of the physical characteristics of the produced material showed that the refractive index was 1.4027~1.4446, water content 31.13~44.01%, contact angle 43.99~65.67°, visible light transmittance 26.17~92.13%, and tensile strength 0.0652~0.2528 kgf. The breaking strength were in the range of 0.0872~0.1851 kgf. These results showed the decrease of contact angle and increase of water content by the addition of IsoMA and carbon nanoparticles and that showing both additives made synergy effect of wettability. As a result of the absorbance measurement, no significant difference was observed in all the samples, so it can be judged that the stabilization of nanoparticles in the polymer was maintained. Therefore, these materials considered to satisfy the basic requirements of ophthalmic lenses with high performance of tensile strength, breaking strength and wettability.

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.

Preparation and Characterization of Functional Ophthalmic Polymer Containing Nanoparticles Using Heat Treatment Method After Polymerization.

The functional hydrogel lens containing HEMA (2-hydroxyethylmethacrylate) was manufactured by thermal polymerization and heat treatment method after room temperature polymerization, respectively. In this study, HEMA, EGDMA (ethylene glycol dimethacrylate) and the initiator AIBN (azobisisobutyronitrile) were used for thermal copolymerization and the mixture was heated at 100 °C for 1 hour. And also, HEMA, EGDMA, the initiator and distilled water were used for heat treatment method after room temperature copolymerization and the mixture was heated 80 °C for 1 hour and then treated at 100 °C for 1 hour to produce the hydrogel ophthalmic lens by cast mold method. To make the functional hydrogel lens, ZnPC and platinum octaethyl porphyrin were used as additives. The measurements of the physical characteristics of the copolymerized material showed that refractive index and contact angle of sample was in the range of 1.4010∼1.4585 and 21.46∼87.28°, respectively. In case of heat treatment method after room temperature copolymerization, the refractive index and wettability of sample was higher than that of thermal polymerization. And also, the addition of ZnPC nanoparticles allowed the hydrogel lens to block UV-light. The absorbance value of solution in which the lens prepared by the heat treatment method was immersed were much lower than that of thermal polymerization, so it can be judged that the stabilization of produced polymer maintained well. Based on the results of this study, the produced optical lens can be considered to satisfy the basic requirements of optical lens and can be used effectively as an additive for functional ophthalmic lens material with high refractive index and wettability.

Study on the Wettability of Ophthalmic Hydrogel Lens Containing Graphene Oxide Nanoparticles with Wettability Measurement Method.

For manufacturing ophthalmic lens, HEMA, PVP, Bis-GMA, GO nanoparticles and EGDMA (ethyleneglycol dimethacrylate) were copolymerized in the presence of AIBN as an initiator. After polymerization, the physical properties such as water content, refractive index, contact angle of produced hydrogel lenses were measured. As a result, when GO nanoparticles were added to the Ref. and Ref.-B samples, the wettability increased due to the hydrogen bonding between the GO and the water molecules, which were distributed on the surface. In the case of Ref.-P containing PVP, the probability of hydrogen bonding with the water molecules on the surface was lowered as hydrogen bonding was induced by the nitrogen of PVP and the carboxyl group of the GO nanoparticles; thus, the wettability somewhat decreased. Therefore, GO, which has excellent abrasion resistance, is considered useful as a material for ophthalmic lenses with excellent wettability and strength when added to the general hydrogel lens materials other than hydrophilic materials like PVP.

Preparation and Characterization of Ophthalmic Polymer Containing Pyridine Group and Platinum Nanoparticles with Initiator Behavior Using Photo and Thermal Polymerization.

To fabricate hydrophilic ophthalmic lenses, HEMA, MMA, and AA were mixed as basic monomers, and EGDMA, a cross-linking agent, was added to make a basic combination. To investigate optimal compatibility and conditions of photo polymerization and thermal polymerization, hydrogel lenses were also fabricated by using 2H2M and 2D2P as photo initiators and AIBN and AIPH as thermal initiators. The properties of the lenses were subsequently compared. Each sample was mixed by adding the additive, 3-hydroxypyridine, at a ratio of 1 to 10% and stirred for about 30 minutes using a stirrer. When 3-hydroxypyridine was used as an additive for improving functionality, the water content increased, and the refractive index decreased. By measuring the optical properties, the UV blocking effect was shown to have improved more 3-hydroxypyridine was added. Also, when platinum nanoparticles were used as an additive, they were found to be uniformly distributed on the produced lens. They did not show a great change in the water content and refractive index of the lens.

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.