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Scientists have developed a new cancer drug. So far, they have
tested it only on{{U}} (36) {{/U}}animals. The drug is designed to{{U}}
(37) {{/U}}and kill cancer cells but not healthy cells.
First, the drug enters the cancer and destroys the supply of blood. Then
it releases{{U}} (38) {{/U}}to destroy the cancer ceils.
Researchers at the Massachusetts Institute of Technology in Cambridge
carried out the study. The{{U}} (39) {{/U}}appeared in Nature{{U}}
(40) {{/U}}. A school news release called the drug an "anti-cancer
smart bomb."
Ram Sasisekharan is a professor at M.I.T. He says
his team had to{{U}} (41) {{/U}}three problems. They had to find a way
to destroy the blood vessels, then to{{U}} (42) {{/U}}the growth of new
ones. But they also needed the blood vessels to supply chemicals to destroy the
cancer.
So, the researchers designed a two-part "nanocell". The
cell is{{U}} (43) {{/U}}in nanometers, or
