A conductive gelatin methacrylamide hydrogel for synergistic therapy of osteosarcoma and potential bone regeneration

In this study, a methacrylic gelatin/oxidized dextran/montmorillonite‑strontium/polypyrrole (GOMP) hydrogel was prepared. The GOMP hydrogel had dual network structure which was formed through photoinitiator-initiated double bond polymerization and Schiff base reaction. The network structure led to a sustained release of the antitumor drug, doxorubicin (DOX). Polypyrrole introduced the conductivity and high photothermal conversion capacity to the GOMP hydrogel, which showed a photothermal conversion efficiency of 31.61 % under 808 nm laser radiation. The GOMP hydrogel had good swelling properties in solvents. Further study showed that the GOMP hydrogel had good biocompatibility and excellent biodegradability in vitro and in vivo. The experiments of in vitro tumor therapy and in vivo anti-tumor recurrence indicated that the DOX-loaded GOMP hydrogel had synergistic effects on tumor cell apoptosis based on chemotherapy and photothermal therapy. In addition, montmorillonite‑strontium (MMT-Sr) doped in the hydrogel not only improved the mechanical properties of the hydrogel but also promoted potential bone regeneration. The multifunctional DOX-loaded GOMP hydrogel with bone regeneration, photothermal therapy, and chemotherapy functions has great potential application for treating osteosarcoma.