Augmentation of postswelling surgical sealant potential of adhesive hydrogels.

ABSTRACT

Two-component hydrogels formed with star polyethylene glycol amine and linear dextran aldehyde polymers (PEGdextran) show promise as tissue-specific surgical sealants. However, there is a significant loss of adhesion strength to soft tissues following PEGdextran swelling, which may limit material ability to appose disjoined tissues and prevent leakage from surgical sites. We covalently incorporated the modified amino acid L-3,4-dihydroxyphenylalanine (L-DOPA) into PEGdextran to enhance postswelling sealant performance. L-DOPA is an essential component of marine animal adhesive plaques and has been used to confer wet adhesion in synthetic materials. As both PEGdextran cohesion and adhesion are mediated by aldehyde-amine interactions, L-DOPA side-groups make it a potent network modulator with potential to affect multiple material properties. Following 1-h submersion in aqueous media, PEGdextran doped with 3 mM L-DOPA/M aldehyde on average swelled 50.3% less, had 287.4% greater stiffness, and had 53.6% greater functional adhesion strength compared to the neat hydrogel. Increased concentrations of L-DOPA up to 11 mM L-DOPA/M aldehyde similarly curtailed swelling and mitigated property loss with hydration, but sacrificed initial functional adhesion strength, material modulus, and biocompatibility. Taken together, these data support tailored L-DOPA conjugation as a promising approach to enhance the clinical performance of PEGdextran sealants.