Fabrication of "Clickable" Hydrogels via Dendron-Polymer Conjugates

Functionalizable hydrogels are of great interest as three-dimensional (3D) scaffolds for cell growth and tissue engineering. The ability to covalently immobilize biologically relevant molecules with accurate control of their density within the hydrogel matrix is highly desirable. Dendron polymer conjugates prepared via Huisgen type "click" reaction provides a unique precursor for reactive hydrogels. A family of dendron polymer conjugates were prepared by coupling second- and third-generation alkyne appended polyester dendrons with linear poly(ethylenc glycol) diazides, PEG2K and PEG6K. Controlled cross-linking of alkyne-functionalized dendron polymer dendron conjugates with a hydrophilic diazide provides hydrogels with gelation efficiencies greater than 80%. Excess leftover alkynes can be used to functionalize these hydrogels as desired. Fine tuning of degree of cross-linking and functionalization is demonstrated by immobilization of streptavidin.