Hybrid Phytoglycogen-Dopamine Nanoparticles as Biodegradable Underwater Adhesives

Abstract

Developing adhesive materials that can selectively degrade into non-toxic by-products, is a key challenge in the materials sciences, particularly for short-term implantable devices and tissue regeneration treatments. Herein, we leverage biodegradable phytoglycogen (PG) nanoparticles (highly-branched glucose polysaccharide nanoparticles) as scaffolds for coupling adhesive dopamine motifs to be used as biodegradable underwater adhesives. The phytoglycogen-dopamine (PG-dopa) hybrid nanoparticles could be synthesised in aqueous solvent, to which the products retained a similar size and particle morphology to the initial PG nanoparticles. The PG-dopa nanoparticles could readily be assembled into dense monolayers on silica substrates through a simple dip-coating procedure. Colloidal probe atomic force microscopy was used to characterise the adhesiveness underwater, where it was found the films produced strain energy release rates towards 8 mJ/m² between hard silica materials. Importantly, the PG-dopa films retained the original biodegradability towards glucosidase enzymes, which can degrade the adhesives in fluids containing these enzymes over time (e.g., 45 U/mL of α-amylase solution degraded the majority of the adhesive films in 30 min). Given the inherent biocompatibility of glycogen materials, we anticipate these adhesives having application in short-term implantable devices.