title: Synthesis and characterization of in situ forming anionic hydrogel as vitreous substitutes.
abstract: The natural vitreous is a biological hydrogel consisting primarily of a collagen and anionic hyaluronate. It is surgically removed in many ocular diseases and replaced with fluids, gases, or silicone oils. We have been interested in developing synthetic hydrogels as vitreous substitutes. In this study, we combined the stiffness and hydrophobicity of polymethacrylamide (PMAM) and the anionic nature of polymethacrylate (PMAA) to make copolymers that would mimic the natural vitreous. We used bis-methacryloyl cystamine (BMAC) to introduce thiol groups for reversible crosslink. The Mnof copolymers ranged from ∼100 k to ∼200 k Da (polydisperisty index of 1.47-2.63) and their composition as determined by titration,1H NMR and disulfide test were close to the feed ratio. The reactivities of monomers were as follows: MAM > MAA ∼ BMAC. Copolymers with higher MAA contents gelled faster, swelled more, and had higher storage modulus (1.5 to 100 Pa) comparable to that of the natural vitreous. We evaluated the biocompatibility of copolymers by electric cell-substrate impedance sensing (ECIS) using human retinal pigment epithelial cells, primary porcine retinal pigmented epithelial cells, human microvascular endothelial cells adult dermis, and a fibroblast line 3T3. The biocompatibility decreases as the content of BMAC increases. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 977-988, 2017.
authors.affiliation: Department of Ophthalmology and Visual Sciences, WA University School of Medicine, Saint Louis, Missouri.
authors.forename: Jue
authors.initials: J
authors.lastname: Liang
authors.affiliation: Department of Ophthalmology and Visual Sciences, WA University School of Medicine, Saint Louis, Missouri.
authors.forename: Jessica J
authors.initials: JJ
authors.lastname: Struckhoff
authors.affiliation: Department of Ophthalmology and Visual Sciences, WA University School of Medicine, Saint Louis, Missouri.
authors.forename: Hongwei
authors.initials: H
authors.lastname: Du
authors.affiliation: Department of Ophthalmology and Visual Sciences, WA University School of Medicine, Saint Louis, Missouri.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Hamilton
authors.affiliation: Department of Ophthalmology and Visual Sciences, WA University School of Medicine, Saint Louis, Missouri.|Department of Energy, Environmental and Chemical Engineering, WA University in St. Louis, Saint Louis, Missouri.|Department of Research, Veterans Affairs Medical Center, Saint Louis, Missouri.
authors.forename: Nathan
authors.initials: N
authors.lastname: Ravi
mesh_terms: D000818:Animals; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D020100:Hydrogels / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D008422:Materials Testing; D051379:Mice; D041681:NIH 3T3 Cells; D011109:Polymethacrylic Acids / Q000138:chemical synthesis / Q000737:chemistry / Q000494:pharmacology; D055213:Retinal Pigment Epithelium / Q000166:cytology / Q000378:metabolism*; D013552:Swine; D014822:Vitreous Body
chemical_list: D020100:Hydrogels; D011109:Polymethacrylic Acids
keywords: ECIS; in situ forming hydrogel; reversible crosslink; vitreous substitute