Beyond thermal protection: Injectable self-healing chitosan hydrogel in liver tumor thermal ablation

Thermal ablation technology is crucial for treating early-stage primary tumors. However, the "water isolation" during clinical surgery is limited by unstable thermal protection caused by fluid loss. More seriously, it is prone to intraoperative bleeding, cancer cell metastasis, and postoperative tissue adhesion. Here we introduce a "one stone, four birds" strategy, which utilizes a self-healing chitosan hydrogel without drug assistance to offer four abilities, including thermal protection, hemostasis, anti-tumor metastasis and anti-tissue adhesion. A rabbit VX2 liver transplantation tumor model is established. The self-healing chitosan hydrogel, crosslink of hydroxyethyl chitosan (HC) and dual aldehyde-PEG (Ald-PEG-Ald) using dynamic Schiff base, adheres to the liver surface and remains in situ upon minimally invasive injection, resulting in outstanding thermal protection compared with saline. The temperature of the isolated tissue near the ablation foci remains below 42 °C. Moreover, the self-healing property of the hydrogel can prevent cell leakage during the procedure, thus avoiding intraoperative bleeding, tumor metastasis and postoperative abdominal adhesion. Therefore, this work identified four efficacies of the self-healing chitosan hydrogel in thermal ablation of metastatic liver tumors, providing an advanced alternative for clinical application.