Enzymatically Degradable Polyester-Based Adhesives

A designed 3,4-dihydroxyphenylalanine (DOPA) mimetic enzymatic degradable synthetic adhesive with good adhesion to soft tissue and metals made by a simple two-step reaction is presented in this article. This adhesive has degradable polycaprolactone-type of repeat units together with glycidyl methacrylate (GMA) and oligo(ethylene glycol) methacrylate (OEGMA) on the polymer backbone. Radical initiated copolymerization of 2-methylene-1,3-dioxepane (MDO), glycidyl methacrylate (GMA) and OEGMA followed by immobilization of catechol group on epoxy rings of GMA provided the adhesive material. Fe(acac)₃ was proved to be the most effective cross-linking agent with lap shear strength of 13.13 ± 1.74 kPa and 218.4 ± 16.0 kPa on soft tissue (porcine skin) and metal (aluminum), respectively. The cross-linked adhesive showed good adhesion stability in pH 7 PBS buffer at 37 °C for at least 1 week. Because of the high adhesive strength, enzymatic degradability, and low toxicity, the material is a promising candidate for future studies as medical glue.