title: Transglutaminase crosslinked gelatin as a tissue engineering scaffold.
abstract: Gelatin is one of the most commonly used biomaterials for creating cellular scaffolds due to its innocuous nature. In order to create stable gelatin hydrogels at physiological temperatures (37 degrees C), chemical crosslinking agents such as glutaraldehyde are typically used. To circumvent potential problems with residual amounts of these crosslinkers in vivo and create scaffolds that are both physiologically robust and biocompatible, a microbial transglutaminase (mTG) was used in this study to enzymatically crosslink gelatin solutions. HEK293 cells encapsulated in mTG-crosslinked gelatin proliferated at a rate of 0.03 day(-1). When released via proteolytic degradation with trypsin, the cells were able to recolonize tissue culture flasks, suggesting that cells for therapeutic purposes could be delivered in vivo using an mTG-crosslinked gelatin construct. Upon submersion in a saline solution at 37 degrees C, the mTG-crosslinked gelatin exhibited no mass loss, within experimental error, indicating that the material is thermally stable. The proteolytic degradation rate of mTG-crosslinked gelatin at RT was slightly faster than that of thermally-cooled (physically-crosslinked) gelatin. Thermally-cooled gelatin that was subsequently crosslinked with mTG resulted in hydrogels that were more resistant to proteolysis. Degradation rates were found to be tunable with gelatin content, an attribute that may be useful for either long-time cell encapsulation or time-released regenerative cell delivery. Further investigation showed that proteolytic degradation was controlled by surface erosion.
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742.
authors.forename: C W
authors.initials: CW
authors.lastname: Yung
authors.affiliation: Center for Biosystems Research, University of Maryland Biotechnology Institute, College Park, MD 20742.|Department of Chemical and Biochemical Engineering, University of Maryland, Baltimore County, Baltimore, MD 21250.
authors.forename: L Q
authors.initials: LQ
authors.lastname: Wu
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742.
authors.forename: J A
authors.initials: JA
authors.lastname: Tullman
authors.affiliation: Center for Biosystems Research, University of Maryland Biotechnology Institute, College Park, MD 20742.|Department of Chemical and Biochemical Engineering, University of Maryland, Baltimore County, Baltimore, MD 21250.
authors.forename: G F
authors.initials: GF
authors.lastname: Payne
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742.|Center for Biosystems Research, University of Maryland Biotechnology Institute, College Park, MD 20742.
authors.forename: W E
authors.initials: WE
authors.lastname: Bentley
authors.affiliation: Department of Chemical and Biomolecular Engineering, University of Maryland, College Park, MD 20742.
authors.forename: T A
authors.initials: TA
authors.lastname: Barbari
mesh_terms: D001672:Biocompatible Materials; D002460:Cell Line; D049109:Cell Proliferation; D004795:Enzyme Stability; D005780:Gelatin / Q000737:chemistry*; D006801:Humans; D006868:Hydrolysis; D023822:Tissue Engineering; D011503:Transglutaminases / Q000737:chemistry*
chemical_list: D001672:Biocompatible Materials; D005780:Gelatin; D011503:Transglutaminases