DNA-Inspired Adhesive Hydrogels Based on the Biodegradable Polyphosphoesters Tackified by a Nucleobase

Since adhesive hydrogels showed wide applications ranging from wearable soft materials to medical sealants, more and more attention has been paid toward the exploration of novel adhesive hydrogels. However, the difficulty in removing the residue caused by the excessive adhesive strength and sluggish degradation or nondegradation behaviors of the adhesive has always been challenging. Inspired by the multiple complementary hydrogen bond interactions in DNA, the bioinspired nucleobase (A, T, and U) monomers were first synthesized and used to tackify polyphosphoester hydrogels. The multiple hydrogen bonds and hydrophobic interactions between purine rings and pyrimidine functionalities endowed the hydrogels with excellent controllable adhesive properties. Besides this, it has been found that these nucleobase-tackified hydrogels could be easily peeled off without leaving any residue and could be totally degraded under alkaline conditions due to hydrolysis of phosphoester chains. At the same time, they also exhibited controllable biodegradation to different extents under the different pH conditions. The excellent adhesive performance, controllable biodegradation, and excellent biocompatibility showed by this nucleobase-tackified polyphosphoester adhesive hydrogel demonstrated its great potential in wound dressing, as a tissue sealant, and so on.