Tunable Release of Encapsulated Proteins from Polyelectrolyte Complex Hydrogels

In this presentation, we describe the swelling and disintegration behavior and protein release kinetics of polyelectrolyte complex (PEC) hydrogels and their relationship with the hydrogel microstructure and shear properties. Unlike chemically-crosslinked hydrogels, PEC hydrogels have the potential to protectively encapsulate biomacromolecules within their complex coacervate core (or PEC) domains, making them ideal candidates for bio-adhesive, wound-dressing, and drug delivery applications. Recently, we demonstrated that protein additives do not disrupt the microstructure of PEC hydrogels. In this presentation, we provide insights into the swelling and disintegration characteristics of PEC hydrogels under physiologically relevant conditions. Moreover, we discuss the protein release kinetics of PEC hydrogels elucidated through circular dichroism experiments. By mixing block polyelectrolytes (bPEs), tuning bPE concentration, and varying bPE end-block length, we exercise control over the swelling behavior and protein release kinetics of hydrogels, exemplifying the use of PEC hydrogels as a platform for precise protein delivery. Our data reveal important design considerations for the future use of PEC hydrogels as therapeutic depots for biomedical applications.