Treating late-stage liver cancer can be extremely difficult, with drugs that prove effective in healthy organs causing high levels of toxicity when introduced to cirrhotic livers. A newly-developed nanoparticle delivery system could improve the situation, with early tests showing it to be effective as a non-toxic treatment in experiments with laboratory mice.

Primary liver cancer causes more deaths across the globe than any other cancer. According to the Centers for Disease Control and Prevention, it's responsible for some 28,000 deaths each year in the US alone, and the five-year survival rate is just 17 percent. The number of case occurrences has also increased over the last few decades, making the search for effective treatments even more pressing.

A research team from the University of Texas Southwestern Medical Center focused on using short nucleic acids called microRNAs (miRNAs) to tackle the cancer. While miRNAs are a good candidate treatment, acting as natural tumor suppressors, attempts to get them into target cells have so far been unsuccessful, with not a single carrier providing efficient delivery without causing amplified toxicity.

With the clear goal of developing a non-toxic carrier, the researchers set about synthesizing 1,500 different types of nanoparticle, trying out varying chemicals, physical properties and sizes. Eventually, the team was able to identify a dendrimer nanoparticle carrier that it believed would be able to transport the miRNAs to late-stage tumor sights with low toxicity levels.

The new carrier was successfully tested on laboratory mice with an aggressive form of liver cancer, with the treatment inhibiting tumor growth and significantly extending survival. While clinical trials will be necessary to confirm that the method is effective, the study is an important step towards a better treatment option for late stage liver cancer.

The researchers published their findings in the journal Proceedings of the National Academy of Sciences.