A hydrogen generator enhances immunogenic transarterial chemoembolization in hepatocellular carcinoma

Conventional transarterial chemoembolization (TACE) regimens for hepatocellular carcinoma (HCC) are often compromised in efficacy due to hypoxia and acidosis within the tumor microenvironment (TME), frequently leading to unsatisfactory treatment outcomes and tumor recurrence. To overcome these limitations, this study introduces an innovative approach by incorporating a hydrogen generator (calcium hydride, CaH₂) into an epirubicin (EPI)-iodized oil embolization system. This design enables local hydrogen release to remodel the TME following TACE, thereby enhancing the combined chemo-immunotherapeutic antitumor response. Nano-CaH₂ particles, co-delivered locally via TACE, undergo hydrolysis to continuously release hydrogen gas (H₂) and calcium ions (Ca²⁺). This reaction disrupts mitochondrial function in cancer cells, reduces oxygen consumption, alleviates tumor hypoxia, and consequently counteracts chemoresistance. Simultaneously, EPI induces immunogenic cell death (ICD) in moribund tumor cells, activating the host's antitumor immune response. Additionally, the hydroxide ions generated from CaH₂ hydrolysis neutralize the acidic TME, alleviating immunosuppression and further amplifying the chemo-immunotherapeutic synergy mediated by TACE. This strategy presents a novel method to improve TACE efficacy and facilitate its integration with immunotherapy, demonstrating considerable potential for clinical translation.