Interpenetrating polymer network (IPN) hydrogels represent a promising class of injectable biomaterials for peptide delivery due to their tunable mechanical properties and capacity to recover structure upon deformation. This work investigates ionic charge and strength as a design parameter to modulate IPN structure and recovery, using naturally-derived polysaccharides, κ-carrageenan and hyaluronic acid (HA) without chemical modification. We systematically evaluated the effects of mono-, di-, and trivalent cations on IPN formation and viscoelastic behavior using FTIR spectroscopy, rheology, and microrheology. FTIR analysis revealed valency-dependent spectral shifts consistent with semi-IPN formation, while rheology revealed recovery behavior governed by ionic charge and strength. Collectively, these findings highlight ion charge and strength as critical design levers which may be leveraged in tailoring microstructure of hydrogels for injectable applications.
Ongoing work focuses on incorporating epidermal growth factors (EGF) into the optimized interpenetrated matrix to achieve sustained and stimuli-responsive peptide release. This strategy aims to address long-standing challenges in peptide stability and bioavailability in dynamic wound environments. By leveraging the dynamic nature of ionic interactions within the hydrogel, this platform enables controlled release kinetics and establishes a stimuli-responsive platform for localized peptide delivery of Epidermal Growth Factor (EGF), with the potential to improve therapeutic stability, retention, and efficacy in wound healing and skin regeneration applications.
