title: An injectable thiol-acrylate poly(ethylene glycol) hydrogel for sustained release of methylprednisolone sodium succinate.
abstract: Clinically available injectable hydrogels face technical challenges associated with swelling after injection and toxicity from unreacted constituents that impede their performance as surgical biomaterials. To overcome these challenges, we developed a system where chemical gelation was controlled by a conjugate Michael addition between thiol and acrylate in aqueous media, with 97% monomer conversion and 6 wt.% sol fraction. The hydrogel exhibited syneresis on equilibration, reducing to 59.7% of its initial volume. It had mechanical properties similar to soft human tissue with an elastic modulus of 189.8 kPa. Furthermore, a mesh size of 6.9 nm resulted in sustained release of methylprednisolone sodium succinate with a loading efficiency of 2 mg/mL. Functionalization with 50 μg/mL of an oligolysine peptide resulted in attachment of freshly isolated murine mesenchymal stem cells. The rational design of the physical, chemical and biological properties of the hydrogel makes it a potentially promising candidate for injectable applications.
authors.affiliation: Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. cpritcha@mit.edu
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Pritchard
authors.forename: Timothy M
authors.initials: TM
authors.lastname: O'Shea
authors.forename: Daniel J
authors.initials: DJ
authors.lastname: Siegwart
authors.forename: Eliezer
authors.initials: E
authors.lastname: Calo
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Anderson
authors.forename: Francis M
authors.initials: FM
authors.lastname: Reynolds
authors.forename: John A
authors.initials: JA
authors.lastname: Thomas
authors.forename: Jonathan R
authors.initials: JR
authors.lastname: Slotkin
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Woodard
authors.forename: Robert
authors.initials: R
authors.lastname: Langer
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D020100:Hydrogels / Q000737:chemistry*; D007267:Injections; D059630:Mesenchymal Stem Cells / Q000378:metabolism; D008776:Methylprednisolone Hemisuccinate / Q000008:administration & dosage / Q000737:chemistry*; D051379:Mice; D011092:Polyethylene Glycols / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D020100:Hydrogels; D013438:Sulfhydryl Compounds; D011092:Polyethylene Glycols; D008776:Methylprednisolone Hemisuccinate