Fabrication, Chemical Modification, And Topographical Patterning Of Reactive Gels Assembled From Azlactone-Functionalized Polymers And A Diamine

The work reported here demonstrates an approach to the fabrication of chemically reactive and topographically patterned hydrogels using the azlactone-functionalized polymer poly(2-vinyl-4,4'-dimethylazlactone) (PVDMA) and the hydrophilic diamine Jeffamine (R). Gels were initially assembled in DMSO but can be subsequently transferred into aqueous media to form hydrogels. Spectroscopic characterization of assembled gels demonstrated that variation in the stoichiometric ratio of azlactones to amines during gel synthesis permits control over the extent of crosslinking in the gels. Residual azlactones not consumed during crosslinking can be exploited to further functionalize these gels with hydrophobic, hydrophilic, and macromolecular amines that influence the physicochemical properties of these materials in aqueous solvents. The surface and bulk of these gels can be differentially functionalized (i.e., different functional groups on the gel surface relative to the bulk) by taking advantage of different rates of diffusion of macromolecular amines versus small molecule amines into assembled gels. Finally, these azlactone-functionalized gels can be topographically patterned with microwell arrays using a replica molding technique and chemically modified postfabrication with amine nucleophiles. This reactive approach to the fabrication of topographically patterned and chemically functionalized hydrogels offers a straightforward method for the rapid synthesis of micropatterned scaffolds of interest in a broad range of applications. (c) 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3185-3194