Complex sentence: According to the San Francisco Chronicle "," Animal studies have shown that some nanoparticles can penetrate cells and tissues, move through the body and brain and cause biochemical damage they also have shown to cause a risk factor in men for testicular cancer.
Split into simpler sentences: According to the San Francisco Chronicle "," Animal studies have shown that some nanoparticles can penetrate cells and tissues, move through the body and brain and cause biochemical damage. They also have shown to cause a risk factor in men for testicular cancer.