A multifunctional biomimetic double-layer composite hydrogel with wet adhesion and antioxidant activity for dural repair

Cerebrospinal fluid (CSF) leakage caused by accidents or diseases resulting from traumatic brain injury, inflammation, tumor erosion and surgery can lead to many complications. In this study, a multifunctional composite double-layer hydrogel was designed by simulating the structure of native dura mater, which was composed of polyacrylic acid (PAA), polyethyleneimine (PEI), sodium alginate (SA), β-cyclodextrin (β-CD) and edaravone (Ed). The PAA/PEI layer had strong wet adhesion characteristics, while the PEI/SA@β-CD/Ed layer exhibited significant antioxidant, drug release and biocompatibility properties. By controlling the concentration of Ca²⁺, the gelation time can be adjusted rapidly within 95-215 s. Specifically, the final PAA/PEI/SA@β-CD/Ed composite hydrogel exhibited a porous network structure with high porosity and low swelling rate, improved tensile strength, sufficient biodegradability, favourable adhesion performance, enhanced DPPH and ABTS radicals scavenging abilities, and sustained Ed release capacity. In addition, the resulting hydrogel also showed excellent biocompatibility and protective effect on H₂O₂-induced oxidative damage in SH-SY5Y cells. These results preliminarily suggested that the PAA/PEI/SA@β-CD/Ed composite hydrogel would appear to be a promising candidate for dural repair.