title: High water content hydrogel with super high refractive index.
abstract: Transparent, high water content (>65%), and cytocompatible hydrogels, which also possess super high refractive indices (RI > 1.5), are needed for ophthalmological applications. Most hydrogels can achieve either high RI or high water content but not both in the same system because water is a low RI material. Here, high water content/high RI hydrogels fabricated through elevated-temperature UV polymerization of an aqueous solution of acrylamide (AM) and methacrylamide (MAM) with tri(ethylene glycol) dimethacrylate (TEDA) crosslinker are reported. By varying the AM:MAM ratios (2:8 to 8:2) and crosslinker density (5 to 11 mol %), it is discovered that high water content (66%) AM:MAM copolymer hydrogels exhibiting anomalously high refractive indices (1.53); they are also colorless, transparent (99.4%), and cytocompatible with human keratinocytes.
authors.affiliation: School of Chemical and Biomedical Engineering, Nanyang Technological University, 62 Nanyang Drive, Singapore, 637459, Singapore.
authors.forename: Chuncai
authors.initials: C
authors.lastname: Zhou
authors.forename: Daniel E
authors.initials: DE
authors.lastname: Heath
authors.forename: Abdul Rahim Mohamed
authors.initials: AR
authors.lastname: Sharif
authors.forename: Shahrzad
authors.initials: S
authors.lastname: Rayatpisheh
authors.forename: Bernice H L
authors.initials: BH
authors.lastname: Oh
authors.forename: Xu
authors.initials: X
authors.lastname: Rong
authors.forename: Roger
authors.initials: R
authors.lastname: Beuerman
authors.forename: Mary B
authors.initials: MB
authors.lastname: Chan-Park
mesh_terms: D020106:Acrylamide / Q000737:chemistry*; D000178:Acrylamides / Q000737:chemistry*; D001672:Biocompatible Materials / Q000138:chemical synthesis* / Q000494:pharmacology; D002470:Cell Survival / Q000187:drug effects; D003432:Cross-Linking Reagents / Q000737:chemistry; D006358:Hot Temperature; D006801:Humans; D020100:Hydrogels / Q000138:chemical synthesis* / Q000494:pharmacology; D015603:Keratinocytes / Q000166:cytology / Q000187:drug effects; D009885:Ophthalmology; D011092:Polyethylene Glycols / Q000737:chemistry; D058105:Polymerization; D011109:Polymethacrylic Acids / Q000737:chemistry; D061251:Primary Cell Culture; D012031:Refractometry; D014466:Ultraviolet Rays; D014867:Water / Q000737:chemistry
chemical_list: D000178:Acrylamides; D001672:Biocompatible Materials; D003432:Cross-Linking Reagents; D020100:Hydrogels; D011109:Polymethacrylic Acids; D014867:Water; C020946:triethylene glycol dimethacrylate; D020106:Acrylamide; D011092:Polyethylene Glycols; C045985:methacrylamide
keywords: acrylamide; hydrogels; methacrylamide; ophthalmological biomaterials; refractive index