New Hydrogel Delivers Hydrogen Therapy to Fight Colorectal Cancer

Authors
Journal
Biomaterials Advances
Year
DOI
10.1016/j.bioadv.2026.214955
Study Type
Cell Culture
Outcome
Positive
Peer Reviewed
Yes
Country
China
Health Condition
Colorectal Cancer
Body System
Digestive System

TL;DR

An oxygen-depleting hydrogel protected Clostridium butyricum under aerobic tumor conditions, allowing the bacteria to continuously generate hydrogen and antitumor metabolites that disrupted cancer cell redox balance, impaired mitochondrial respiration, and suppressed tumor growth.

Key Finding

An injectable gel containing hydrogen-producing bacteria successfully delivered sustained hydrogen therapy to colorectal tumors in animal studies, suppressing tumor growth by disrupting cancer cell energy production.

Summary

Researchers developed a special gel containing bacteria that produce hydrogen gas, designed to be injected directly into colorectal tumors. The gel creates an oxygen-free environment that keeps the bacteria alive even in oxygen-rich areas of tumors. In laboratory and animal studies, the hydrogen gas and bacterial byproducts together disrupted cancer cells' energy production and triggered cell death, slowing tumor growth.

Practical Takeaway

This is early-stage research conducted in laboratory and animal models only—not human studies. While it suggests hydrogen gas may have anti-cancer potential when delivered directly to tumors, it does not demonstrate safety or effectiveness in people. Much more research would be needed before this approach could be considered for human use.

Abstract

Hydrogen (H2), a non-toxic therapeutic gas, exerts antitumor effects by disrupting intracellular redox homeostasis and inducing mitochondrial dysfunction. The high diffusibility of H2, as well as its storage difficulties, hinders its sustained release at tumor sites. Thus, the therapeutic effect remains limited. Clostridium butyricum exhibits great potential for cancer treatment attributing to its inherent capability of continuous H2 generation. However, its obligate anaerobic nature prevents survival under aerobic conditions, such as the well-vascularized tumor regions with high oxygen levels. To address this challenge, we synthesized a hydrogel with anaerobic interior, based on the oxygen-depleting reaction between laccase and vanillin. As a delivery vehicle for Clostridium butyricum, this hydrogel (CB@Anaerobic-Gel) maintained its viability under aerobic conditions. As a result, the encapsulated bacteria can produce H2 and metabolites throughout tumor regions-including both hypoxic zones and well-vascularized areas. In vitro studies confirmed that H2 released from CB@Anaerobic-Gel disrupts redox homeostasis and suppresses mitochondrial respiration in colon cancer cells. These effects synergized with metabolites from C. butyricum to induce tumor cell death. In vivo experiments showed that intratumoral injection of CB@Anaerobic-Gel significantly suppressed tumor growth. Therefore, this method offers a novel approach for tumor hydrogen therapy and a versatile platform for oxygen-sensitive therapeutics.