COLUMBIA, Mo. — Each year, pharmaceutical companies invest millions of dollars to test drugs, many of which will never reach the market because of side effects found only during human clinical trials. At the same time, the number of patients waiting for organ transplants continues to increase. In the past 10 years, this number has nearly doubled. Now, a new study led by a University of Missouri-Columbia physics researcher might present new solutions to both problems with the help of a very special printer.