title: Porphyrin-cross-linked hydrogel for fluorescence-guided monitoring and surgical resection.
abstract: We demonstrate that porphyrins can be used as efficient cross-linkers to generate a new class of hydrogels with enabling optical properties. Tetracarboxylic acid porphyrins reacted with PEG diamines to form a condensation polyamide in a range of appropriate conditions, with respect to reaction time, diisopropylethylamine initiator concentration, porphyrin-to-PEG ratio, porphyrin concentration, and PEG size. The network structure of the hydrogel maintained a porphyrin spacing that prevented excessive fluorescence self-quenching despite high porphyrin density. The near-infrared properties readily enabled low background, noninvasive fluorescence monitoring of the implanted hydrogel in vivo, as well as its image-guided surgical removal in real time using a low-cost fluorescence camera prototype. Emission could be tuned by incorporating copper metalloporphyrins into the network. The approach of creating hydrogels using cross-linking porphyrin comonomers creates opportunities for new polymer designs with strong optical character.
authors.affiliation: Institute of Biomaterials and Biomedical Engineering, University of Toronto, ON, M5G 1L7, Canada.
authors.forename: Jonathan F
authors.initials: JF
authors.lastname: Lovell
authors.forename: Aron
authors.initials: A
authors.lastname: Roxin
authors.forename: Kenneth K
authors.initials: KK
authors.lastname: Ng
authors.forename: Qiaochu
authors.initials: Q
authors.lastname: Qi
authors.forename: Jesse D
authors.initials: JD
authors.lastname: McMullen
authors.forename: Ralph S
authors.initials: RS
authors.lastname: DaCosta
authors.forename: Gang
authors.initials: G
authors.lastname: Zheng
mesh_terms: D000818:Animals; D003300:Copper / Q000737:chemistry / Q000378:metabolism; D003432:Cross-Linking Reagents / Q000737:chemistry; D005021:Ethylamines / Q000737:chemistry; D020100:Hydrogels / Q000737:chemistry*; D051379:Mice; D057054:Molecular Imaging / Q000379:methods*; D009757:Nylons / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D011166:Porphyrins / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013055:Spectrophotometry, Infrared; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000379:methods
chemical_list: D003432:Cross-Linking Reagents; D005021:Ethylamines; D020100:Hydrogels; D009757:Nylons; D011108:Polymers; D011166:Porphyrins; D011092:Polyethylene Glycols; C027070:N,N-diisopropylethylamine; D003300:Copper