title: Long-term spatially defined coculture within three-dimensional photopatterned hydrogels.
abstract: Spatially controlled coculture in three-dimensional environments that appropriately mimic in vivo tissue architecture is a highly desirable goal in basic scientific studies of stem cell physiological processes (e.g., proliferation, matrix production, and tissue repair) and in enhancing the development of novel stem-cell-based clinical therapies for a variety of ailments. This study describes a novel fabrication system for photopatterning and assembling cell-laden oligo(polyethylene glycol)-fumarate:poly(ethylene glycol)-diacrylate hydrogels with high spatial fidelity and thickness using a controlled, inert nitrogen environment without the need for expensive precision equipment. Cross-linking was performed using Irgacure-2959 photoinitiator and 365-nm light (∼7 mW/cm²) to form gels ranging from 0.9 to 3 mm in width. Employing a nitrogen environment increased gel thickness up to 240%, generating gels > 1 mm thick before swelling. This technique was further applied for spatially controlled patterning of primary tendon/ligament fibroblasts and marrow stromal cells in a single 1.5-mm-thick laminated hydrogel construct. Cells encapsulated using this technique maintained viability over 14 days in culture. This system potentially enables better understanding of paracrine effects on a range of stem cell functions and therefore may be useful as an in vitro model system for a wide array of regenerative medicine applications.
authors.affiliation: Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia.
authors.forename: Taymour M
authors.initials: TM
authors.lastname: Hammoudi
authors.forename: Hang
authors.initials: H
authors.lastname: Lu
authors.forename: Johnna S
authors.initials: JS
authors.lastname: Temenoff
mesh_terms: D000818:Animals; D002417:Cattle; D049109:Cell Proliferation; D002470:Cell Survival; D002478:Cells, Cultured; D018920:Coculture Techniques / Q000379:methods; D020100:Hydrogels / Q000737:chemistry* / Q000528:radiation effects*; D008027:Light; D059630:Mesenchymal Stem Cells / Q000166:cytology / Q000502:physiology; D055616:Microtechnology / Q000379:methods; D055095:Optics and Photonics; D013710:Tendons / Q000166:cytology / Q000502:physiology; D013997:Time Factors; D023822:Tissue Engineering / Q000295:instrumentation* / Q000379:methods*; D054457:Tissue Scaffolds / Q000737:chemistry
chemical_list: D020100:Hydrogels
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