Protein release from redox responsive hydrogels

Hydrogel networks that can enable slow release of therapeutic proteins are attractive candidates for various biomedical applications. For example, these materials can serve as valuable coatings on medical implants that can present proteins to the cellular environment to enable adaptation of the foreign implant materials in the body. These materials can also be used as post-operative fillers to release therapeutic peptides and proteins to eradicate any residual tumorigenic cells. In this study, three dimensional hydrogel networks containing degradable disulfide bonds have been prepared using the Diels-Alder click chemistry. Hydrogels containing different amount of degradable crosslinker were synthesized via the Diels-Alder reaction between furan bearing PEG-based copolymer and disulfide containing bismaleimide crosslinker. Furan bearing copolymer was synthesized via single electron transfer-living radical polymerization (SET-LRP) technique using poly(ethylene glycol) methyl ether methacrylate (PEGMEMA) and furfuryl methacrylate (FuMA). Rheological analysis of different hydrogels with various crosslink densities was carried out during their formation and then their degradation rates were examined in PBS solution and reducing agent containing solution. FITC-labeled bovine serum albumin was loaded into the hydrogels physically during their fabrication. Protein release studies for hydrogels with different crosslink density were carried out in the presence and absence of reducing agent to demonstrate that the extent of release was tunable.