Block Polyelectrolytes Scaffolds for Underwater Injection and Bioadhesion*

In this contribution, we show the preparation of wet bioadhesives consisting of two interpenetrating networks that comprise photocurable gelatin methacryloyl (GelMA) and electrostatically self-assembled block polyelectrolytes (bPEs). GelMA – a chemically-modified extracellular matrix-derived material – has been proposed as a versatile bioadhesive that can replace traditional strategies such as invasive sutures and staples to seal wounds. However, their utilization in biomedical settings is hampered because of their dilution and undesired flow in wet, physiological conditions, leading to weak adhesion to tissue surfaces. Compared to GelMA adhesives, GelMA/bPE adhesives that include a combination of GelMA with bPE self-assembled scaffolds feature robust curing in wet, physiological media. We contrast the adhesion performance and mode of failure of cured GelMA adhesives, comprising a single polymer network, with GelMA/bPE adhesives featuring interpenetrating networks to demonstrate significant improvements in rupture, adhesion, and shear strengths at comparable polymer concentrations. Through parametric studies, we will establish that the bPE content is the primary control parameter enabling tunable performance of the hybrid GelMA/bPE adhesives.