title: Visible light photoinitiation of mesenchymal stem cell-laden bioresponsive hydrogels.
abstract: Biological activity can be added to synthetic scaffolds by incorporating functional peptide sequences that provide enzyme-mediated degradation sites, facilitate cellular adhesion or stimulate signaling pathways. Poly(ethylene glycol) diacrylate is a popular synthetic base for tissue engineering scaffolds because it creates a hydrophilic environment that can be chemically manipulated to add this biological functionality. Furthermore, the acrylate groups allow for encapsulation of cells using photopolymerization under physiological conditions. One complication with the addition of these peptides is that aromatic amino acids absorb light at 285 nm and compete with the ultraviolet (UV)-sensitive photoinitiators such as IrgacureTM 2959 (I2959), the most commonly used initiator for cytocompatible photoencapsulation of cells into synthetic scaffolds. In this study we define non-toxic conditions for photoencapsulation of human mesenchymal stem cells (hMSC) in PEGDA scaffolds using a visible light photoinitiator system composed of eosin Y, triethanolamine and 1-vinyl-2-pyrrolidinone. This visible light photoinitiator produced hydrogel scaffolds with an increased viability of encapsulated hMSCs and a more tightly crosslinked network in one-third the time of UV polymerization with I2959.
authors.affiliation: Oregon Health & Science University, Department of Orthopaedics & Rehabilitation, 3181 Sam Jackson Park Road, Portland OR 97239, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Bahney
authors.forename: T J
authors.initials: TJ
authors.lastname: Lujan
authors.forename: C W
authors.initials: CW
authors.lastname: Hsu
authors.forename: M
authors.initials: M
authors.lastname: Bottlang
authors.forename: J L
authors.initials: JL
authors.lastname: West
authors.forename: B
authors.initials: B
authors.lastname: Johnstone
mesh_terms: D002470:Cell Survival; D018914:Cells, Immobilized; D006801:Humans; D020100:Hydrogels / Q000737:chemistry / Q000528:radiation effects* / Q000627:therapeutic use; D008027:Light; D059630:Mesenchymal Stem Cells / Q000166:cytology*; D058105:Polymerization; D023822:Tissue Engineering / Q000379:methods*; D054457:Tissue Scaffolds; D014466:Ultraviolet Rays
chemical_list: D020100:Hydrogels