Novel Bismuth-Melanin Biomaterial Dramatically Increases Survival Rates by Shielding the Body From Acute Radiation Syndrome

Beijing researchers develop a dual-action biomaterial that cuts radiation mortality by 40% in trials, offering physical shielding and antioxidant protection.

By: AXL Media

Published: Apr 29, 2026, 7:24 AM EDT

Source: Information for this report was sourced from EurekAlert!

Innovative Supramolecular Strategy for Internal Radiation Shielding

A research team led by Professor Wei Cao at Beijing Normal University has successfully engineered a bismuth-coordinated melanin material designed to protect the body from life-threatening radiation. Published in the journal Supramolecular Materials, the study introduces a new approach to radioprotection by incorporating high-Z elements directly into a biocompatible framework. While traditional internal protectors focus almost exclusively on chemical antioxidant responses, this new material brings physical shielding properties into the body, offering a secondary layer of defense against ionizing energy that was previously difficult to achieve safely.

The Synergistic Benefits of Bismuth and Natural Melanin

The new biomaterial leverages the unique properties of bismuth, the heaviest non-radioactive metal, to provide a physical barrier against photons. By coordinating bismuth with melanin, a substance known for its natural ability to scavenge reactive oxygen species, the team created a compound that addresses both the physical and chemical damage caused by radiation. According to Professor Cao, the supramolecular coordination chemistry used in this design ensures that the material remains safe for internal use while maximizing its ability to neutralize oxidative stress and provide high-density shielding.

Significant Survival Gains in High-Dose Exposure Trials

Experimental results from mouse models demonstrated the material's potential to mitigate acute radiation syndrome, which typically causes hematopoietic failure and systemic organ damage. In trials involving 6 Gy total body gamma-ray irradiation, a single dose of the bismuth-melanin compound increased the 30-day survival rate from a baseline of 20% to 60%. These results indicate that the protector is effective even when administered in close temporal proximity to a severe radiation event, suggesting a broad window of utility for emergency medical scenarios.