title: Pd-porphyrin-cross-linked implantable hydrogels with oxygen-responsive phosphorescence.
abstract: Development of long-term implantable luminescent biosensors for subcutaneous oxygen has proved challenging due to difficulties in immobilizing a biocompatible matrix that prevents sensor aggregation yet maintains sufficient concentration for transdermal optical detection. Here, Pd-porphyrins can be used as PEG cross-linkers to generate a polyamide hydrogel with extreme porphyrin density (≈5 × 10(-3) m). Dye aggregation is avoided due to the spatially constraining 3D mesh formed by the porphyrins themselves. The hydrogel exhibits oxygen-responsive phosphorescence and can be stably implanted subcutaneously in mice for weeks without degradation, bleaching, or host rejection. To further facilitate oxygen detection using steady-state techniques, an oxygen-non-responsive companion hydrogel is developed by blending copper and free base porphyrins to yield intensity-matched luminescence for ratiometric detection.
authors.affiliation: Departments of Biomedical Engineering and Chemical and Biological Engineering, 210 Bonner Hall, University at Buffalo, Buffalo, NY, 14260, USA.
authors.forename: Haoyuan
authors.initials: H
authors.lastname: Huang
authors.forename: Wentao
authors.initials: W
authors.lastname: Song
authors.forename: Guanying
authors.initials: G
authors.lastname: Chen
authors.forename: Justin M
authors.initials: JM
authors.lastname: Reynard
authors.forename: Tymish Y
authors.initials: TY
authors.lastname: Ohulchanskyy
authors.forename: Paras N
authors.initials: PN
authors.lastname: Prasad
authors.forename: Frank V
authors.initials: FV
authors.lastname: Bright
authors.forename: Jonathan F
authors.initials: JF
authors.lastname: Lovell
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate / Q000737:chemistry*; D008163:Luminescent Measurements; D008652:Mesoporphyrins / Q000737:chemistry*; D008665:Metalloporphyrins / Q000737:chemistry*; D051379:Mice; D008807:Mice, Inbred BALB C; D009757:Nylons / Q000737:chemistry; D010100:Oxygen / Q000032:analysis*; D011092:Polyethylene Glycols / Q000737:chemistry; D012867:Skin / Q000737:chemistry / Q000378:metabolism
chemical_list: D008652:Mesoporphyrins; D008665:Metalloporphyrins; D009757:Nylons; C079625:palladium-meso-tetra(4-carboxyphenyl)porphine; D020136:Hydrogel, Polyethylene Glycol Dimethacrylate; D011092:Polyethylene Glycols; D010100:Oxygen
keywords: hydrogels; imaging; implants; oxygen sensing; phosphorescence; porphyrins