Development of a mechanical adaptable, moisture retention capable, injectable and adhesive organohydrogel for nucleus pulposus repairing

Developing mechanical adaptable injectable gel with nucleus pulposus (NP) repairing capability for minimally invasive treatment of intervertebral disc degeneration (IDD) is of great importance in medical practice. In current work, inspired by the outcomes of polyvinyl alcohol and glycerol based injectable organohydrogel (GPG) in IDD control and the great potential of animal glue in tissue adhesion, a novel injectable and self-crosslinking adhesive organohydrogel GPG-AG was fabricated. The mechanical performance of the GPG-AG was systematically studied, possessing viscoelastic properties close to NP accompanied with strong adhesion to intervertebral disc to avoid dynamic loading induced leakage postinjection. In addition, the swelling behavior, water retention capability and degradation of the organohydrogel <i>in situ</i> was also explored. <i>In vitro</i> cellular test showed the as-fabricated organohydrogel was able to upgrade aggrecan expression while downregulate matrix metallopeptidase-13 (MMP-13) synthesis. Astoundingly, the organohydrogel revealed anti-inflammation potential of alleviating excessive reactive oxygen species, consequently creating a favored microenvironment for NP repairing. The corresponding <i>in vivo</i> study showed the outcome in intervertebral disc height index of the GPG-AG treated group after needle puncture was superior to previously reported GPG and control group. Taken together, this organohydrogel is expected to serve as a promising candidate for IDD control.