The latest data from University of Pittsburgh researchers shows that their intravenous therapy can protect bone marrow in mice, with 90 per cent of the animals surviving 30 days, compared to just 58 per cent in the control group.
For the last six years, much of the world has been coming to terms with increased terrorist attacks.
One of the biggest worries is that a radiological or nuclear bomb will fall into the wrong hands and be used to murder millions.
This has prompted numerous pharma firms to begin developing therapies that could protect against the devastating effects of ionising radiation.
This not only includes treatments that could save lives during and after a nuclear attack, but also those which could be used beforehand.
"In previous studies, we demonstrated that gene therapy can be both swallowed in liquid form and inhaled through a nebuliser prior to radiation exposure to protect healthy tissues from damage," said Prof. Joel Greenberger, chairman of the department of radiation oncology, University of Pittsburgh School of Medicine.
"In this study, we found that the same therapy administered intravenously also offers protection during exposure to whole-body irradiation."
The results were presented at the 49th annual meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO) in Los Angeles, US.
Prof. Greenberger and his team tested the effects of an initial 9.5 Gy dose of radiation in mice over 30 days.
While one set of mice received no treatment, the other set were administered manganese superoxide dismutase plasmid liposome (MnSOD-PL) gene therapy prior to radiation.
This time limit was used as experts believe a significant number of the population would die within 30 days of receiving a large dose of radiation to the entire body.
Between 30 and 330 days, there was no difference in survival rates between the two groups.
So although the protective effects don't last long, this also suggests systemic MnSOD-PL treatment was not harmful to survival.
"Intravenous administration of gene therapy appears to prevent the damaging effects of radiation, suggesting it is a viable delivery method," said Prof. Greenberger.
"Future clinical studies will tell us whether this therapy can protect people from the deadly effects of radiation."