title: Visible-light-initiated thiol-acrylate photopolymerization of heparin-based hydrogels.
abstract: An in situ heparin-based forming hydrogel that cures under visible-light is formulated using eosin Y as a photoinitiator with triethanolamine as an electron donor to initiate reaction of thiolated-heparin with acrylate-ended poly(ethylene glycol). Formulations and irradiation conditions are presented for control of heparin content (1.6 to 3.3% w/v), modulus (100-10,000 Pa), and gelation time (30-600 s). Encapsulation of 3T3 fibroblasts in the hydrogel gave over 96% viability for all conditions examined. In vitro characterization of epidermal growth factor released from the hydrogel confirmed that the growth factor remains bioactive. The ability to deliver growth factors, fast gelation kinetics under visible light, and independent control of physical and biochemical properties makes this system a promising candidate for use in regenerative medicine. In particular, irradiation conditions that achieve gelation in 150s are compatible with the stringent light exposure limits of the retina, which affords a wide safety margin for use with other tissues.
authors.affiliation: Division of Chemistry and Chemical Engineering, California Institute of Technology , 1200 East California Boulevard, Pasadena, California 91125, United States.
authors.forename: Amy
authors.initials: A
authors.lastname: Fu
authors.forename: Kihak
authors.initials: K
authors.lastname: Gwon
authors.forename: Mihye
authors.initials: M
authors.lastname: Kim
authors.forename: Giyoong
authors.initials: G
authors.lastname: Tae
authors.forename: Julia A
authors.initials: JA
authors.lastname: Kornfield
mesh_terms: D000179:Acrylates / Q000737:chemistry / Q000494:pharmacology / Q000528:radiation effects*; D000818:Animals; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D003432:Cross-Linking Reagents / Q000737:chemistry / Q000494:pharmacology / Q000528:radiation effects; D006493:Heparin / Q000737:chemistry / Q000494:pharmacology / Q000528:radiation effects*; D020100:Hydrogels / Q000737:chemistry / Q000494:pharmacology / Q000528:radiation effects*; D008027:Light; D051379:Mice; D041681:NIH 3T3 Cells; D058105:Polymerization; D013438:Sulfhydryl Compounds / Q000737:chemistry / Q000494:pharmacology / Q000528:radiation effects*
chemical_list: D000179:Acrylates; D003432:Cross-Linking Reagents; D020100:Hydrogels; D013438:Sulfhydryl Compounds; D006493:Heparin; C036658:acrylic acid