title: In vitro perfusion of engineered heart tissue through endothelialized channels.
abstract: In engineered heart tissues (EHT), oxygen and nutrient supply via mere diffusion is a likely factor limiting the thickness of cardiac muscle strands. Here, we report on a novel method to in vitro perfuse EHT through tubular channels. Adapting our previously published protocols, we expanded a miniaturized fibrin-based EHT-format to a larger six-well format with six flexible silicone posts holding each EHT (15×25×3 mm³). Thin dry alginate fibers (17×0.04×0.04 mm) were embedded into the cell-fibrin-thrombin mix and, after fibrin polymerization, dissolved by incubation in alginate lyase or sodium citrate. Oxygen concentrations were measured with a microsensor in 14-day-old EHTs (37°C, 21% oxygen) and ranged between 9% at the edges and 2% in the center of the tissue. Perfusion rapidly increased it to 10%-12% in the immediate vicinity of the microchannel. Continuous perfusion (20 μL/h, for 3 weeks) of the tubular lumina (100-500 μm) via hollow posts of the silicone rack increased mean dystrophin-positive cardiomyocyte density (36%±6% vs. 10%±3% of total cell number) and cross sectional area (73±2 vs. 48±1 μm²) in the central part of the tissue compared to nonperfused EHTs. The channels were populated by endothelial cells present in the reconstitution cell mix. In conclusion, we developed a novel approach to generate small tubular structures suitable for perfusion of spontaneously contracting and force-generating EHTs and showed that prolonged perfusion improved cardiac tissue structure.
authors.affiliation: 1 Department of Experimental Pharmacology and Toxicology, University Medical Center Hamburg-Eppendorf , Hamburg, Germany .
authors.forename: Ingra
authors.initials: I
authors.lastname: Vollert
authors.forename: Moritz
authors.initials: M
authors.lastname: Seiffert
authors.forename: Johanna
authors.initials: J
authors.lastname: Bachmair
authors.forename: Merle
authors.initials: M
authors.lastname: Sander
authors.forename: Alexandra
authors.initials: A
authors.lastname: Eder
authors.forename: Lenard
authors.initials: L
authors.lastname: Conradi
authors.forename: Alexander
authors.initials: A
authors.lastname: Vogelsang
authors.forename: Thomas
authors.initials: T
authors.lastname: Schulze
authors.forename: June
authors.initials: J
authors.lastname: Uebeler
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Holnthoner
authors.forename: Heinz
authors.initials: H
authors.lastname: Redl
authors.forename: Hermann
authors.initials: H
authors.lastname: Reichenspurner
authors.forename: Arne
authors.initials: A
authors.lastname: Hansen
authors.forename: Thomas
authors.initials: T
authors.lastname: Eschenhagen
mesh_terms: D000464:Alginates / Q000494:pharmacology; D000818:Animals; D002417:Cattle; D002951:Citrates / Q000494:pharmacology; D016189:Dystrophin / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000187:drug effects; D004730:Endothelium, Vascular / Q000187:drug effects / Q000502:physiology*; D020723:Glucuronic Acid / Q000494:pharmacology; D006321:Heart / Q000187:drug effects*; D006603:Hexuronic Acids / Q000494:pharmacology; D010100:Oxygen / Q000494:pharmacology; D010477:Perfusion / Q000379:methods*; D051381:Rats; D000077559:Sodium Citrate; D023822:Tissue Engineering
chemical_list: D000464:Alginates; D002951:Citrates; D016189:Dystrophin; D006603:Hexuronic Acids; D000077559:Sodium Citrate; D020723:Glucuronic Acid; D010100:Oxygen