title: Covalent Modification of Synthetic Hydrogels with Bioactive Proteins via Sortase-Mediated Ligation.
abstract: Synthetic extracellular matrices are widely used in regenerative medicine and as tools in building in vitro physiological culture models. Synthetic hydrogels display advantageous physical properties, but are challenging to modify with large peptides or proteins. Here, a facile, mild enzymatic postgrafting approach is presented. Sortase-mediated ligation was used to conjugate human epidermal growth factor fused to a GGG ligation motif (GGG-EGF) to poly(ethylene glycol) (PEG) hydrogels containing the sortase LPRTG substrate. The reversibility of the sortase reaction was then exploited to cleave tethered EGF from the hydrogels for analysis. Analyses of the reaction supernatant and the postligation hydrogels showed that the amount of tethered EGF increases with increasing LPRTG in the hydrogel or GGG-EGF in the supernatant. Sortase-tethered EGF was biologically active, as demonstrated by stimulation of DNA synthesis in primary human hepatocytes and endometrial epithelial cells. The simplicity, specificity, and reversibility of sortase-mediated ligation and cleavage reactions make it an attractive approach for modification of hydrogels.
authors.affiliation: †Department of Biological Engineering, ‡Department of Chemical Engineering, §Center for Gynepathology Research, ∥Department of Chemistry and ⊥̂Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts United States.
authors.forename: Elena
authors.initials: E
authors.lastname: Cambria
authors.affiliation: †Department of Biological Engineering, ‡Department of Chemical Engineering, §Center for Gynepathology Research, ∥Department of Chemistry and ⊥̂Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts United States.
authors.forename: Kasper
authors.initials: K
authors.lastname: Renggli
authors.affiliation: †Department of Biological Engineering, ‡Department of Chemical Engineering, §Center for Gynepathology Research, ∥Department of Chemistry and ⊥̂Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts United States.
authors.forename: Caroline C
authors.initials: CC
authors.lastname: Ahrens
authors.affiliation: †Department of Biological Engineering, ‡Department of Chemical Engineering, §Center for Gynepathology Research, ∥Department of Chemistry and ⊥̂Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts United States.
authors.forename: Christi D
authors.initials: CD
authors.lastname: Cook
authors.affiliation: †Department of Biological Engineering, ‡Department of Chemical Engineering, §Center for Gynepathology Research, ∥Department of Chemistry and ⊥̂Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts United States.
authors.forename: Carsten
authors.initials: C
authors.lastname: Kroll
authors.affiliation: †Department of Biological Engineering, ‡Department of Chemical Engineering, §Center for Gynepathology Research, ∥Department of Chemistry and ⊥̂Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts United States.
authors.forename: Andrew T
authors.initials: AT
authors.lastname: Krueger
authors.affiliation: †Department of Biological Engineering, ‡Department of Chemical Engineering, §Center for Gynepathology Research, ∥Department of Chemistry and ⊥̂Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts United States.
authors.forename: Barbara
authors.initials: B
authors.lastname: Imperiali
authors.affiliation: †Department of Biological Engineering, ‡Department of Chemical Engineering, §Center for Gynepathology Research, ∥Department of Chemistry and ⊥̂Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts United States.
authors.forename: Linda G
authors.initials: LG
authors.lastname: Griffith
mesh_terms: D003546:Cysteine Endopeptidases / Q000737:chemistry; D004247:DNA / Q000096:biosynthesis* / Q000187:drug effects; D004717:Endometrium / Q000166:cytology / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000008:administration & dosage / Q000737:chemistry*; D004847:Epithelial Cells / Q000187:drug effects; D005260:Female; D022781:Hepatocytes / Q000187:drug effects; D006801:Humans; D020100:Hydrogels / Q000008:administration & dosage / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: D020100:Hydrogels; D004815:Epidermal Growth Factor; D004247:DNA; D003546:Cysteine Endopeptidases