Mussel-Inspired Biocompatible PAADOPA/PAAm Hydrogel Adhesive for Amoxicillin Delivery

The adhesion of drug-loaded hydrogels for topical therapy often drastically deteriorated in humid environments, leading to an ineffective therapeutic concentration. It is necessary to develop a valid strategy for resisting adhesion damage from abundant body fluids and hydrogel detachment from external forces. Herein, we report a mussel-inspired hydrogel adhesive through the introduction of 3,4-dihydroxyphenylalanine (DOPA)-functionalized poly(acrylic acid), named PAADOPA, into polyacrylamide (PAAm) networks. The abundant DOPA moieties endow the PAADOPA/PAAm hydrogel with superior adhesion on various substrates including rough surfaces, smooth surfaces, and tissues. The adhesion strength in the PAADOPA 2.5 /PAAm hydrogel is 3.2 times that of the pure PAAm hydrogel. Most critically, the anti-inflammatory drug amoxicillin was successfully encapsulated into the PAADOPA/PAAm hydrogel, demonstrating superior biocompatibility for the sustained release of the drug. Hence, the obtained amoxicillin-loaded PAADOPA/PAAm hydrogel adhesive is shown to have strong adhesion, superior biocompatibility, and sustained release of drugs, providing promising applications in tissue engineering and biomedicinal fields.