The macrophage blood cells were "armed" with a virus which began to buy cheap moncler jackets and replicate after reaching the cancer target.
Once infected, the cancer cells were destroyed. At the same time the multiplying virus spread to attack neighbouring prostate cancer cells.
Previous attempts at the same strategy were hampered by the poor ability of macrophages to penetrate deep into tumours.
The new approach inserts tiny magnetic particles into the macrophages which can be moved by an external magnet, dragging the cells with them.
In the tests, Cheap moncler women vest for sale, buy 2011 new style women moncler vest, the cells were pulled deep into tumour "spheroids" using an external magnetic force. The more macrophages that could be delivered into cancer cells, the greater the number of cancer cells that were destroyed.
Dr Jay Richardson, from the University of Sheffield, said: "We know that when prostate cancer develops, a type of white blood cells called macrophages flock to the scene.
"Previous research has allowed us to harness these cells to deliver cancer fighting therapies directly into the cancer cells. Now, with some magnetic assistance, we are able to refine this method and wear moncler jackets so that the macrophages reach and deliver the therapy to prostate cancer cells only, leaving healthy cells unharmed."