The technology specifically targets cancer cells
Nanotechnology has been used for the first time to destroy cancer cells with a highly targeted package of "tumour busting" genes.
The technique, which leaves healthy cells unaffected, could potentially offer hope to people with hard-to-treat cancers where surgery is not possible.
Although it has only been tested in mice so far, the researchers hope for human trials in two years.
The UK study is published online by the journal Cancer Research.
The genes were wrapped up in microscopic nano-particles which were taken up by cancer cells, but not their healthy neighbours.
Once inside, the genes stimulated production of a protein which destroys the cancer.
The researchers say the technology could potentially be particularly relevant for people with cancers that are inoperable because they are close to vital organs.
They hope it will eventually also be used to treat cancer that has spread.
Lead researcher Dr Andreas Schatzlein, from the School of Pharmacy in London, said: "Gene therapy has a great potential to create safe and effective cancer treatments but getting the genes into cancer cells remains one of the big challenges in this area.
"This is the first time that nanoparticles have been shown to target tumours in such a selective way, and this is an exciting step forward in the field.
"Once inside the cell, the gene enclosed in the particle recognises the cancerous environment and switches on. The result is toxic, but only to the offending cells, leaving healthy tissue unaffected.
"We hope this therapy will be used to treat cancer patients in clinical trials in a couple of years."
Traditional chemotherapy indiscriminately kills cells in the affected area of the body, which can cause side effects like fatigue, hair loss or nausea.
It is hoped that gene therapy will have fewer associated side effects by targeting cancer cells.
Dr Lesley Walker, of the charity Cancer Research UK, said: "These results are encouraging, and we look forward to seeing if this method can be used to treat cancer in people.
"Gene therapy is an exciting area of research, but targeting genetic changes to cancer cells has been a major challenge.
"This is the first time a solution has been proposed, so it's exciting news."