Saluting Creativity in Engineering

New York, Feb. 16--Creativity and engineers--two words that do go together.

Engineers constantly redefine the world through new inventions and advances in existing technologies. By challenging perceptions, defying conventions, and cross-linking different fields, engineers have contributed to improving our quality of life--from building better cities, to creating artificial skin and organs, to achievements in communications, and even designing the perfect thrill ride.

This month, the National Building Museum in Washington, DC, salutes engineers with a special exhibit, "Breaking Through: The Creative Engineer." The exhibit will open to coincide with National Engineers Week, the national celebration of engineering achievements, which runs from February 22 to 28, 1998. Visitors will be encouraged to explore their own creative capabilities through games, puzzles, and other learning challenges.

One of the engineering innovations highlighted in the exhibit is tissue engineering, a new specialty that creates human tissues for repairing or replacing damaged ones. Researchers active in this field include chemical engineers, materials scientists and engineers, and mechanical and electrical engineers.

The National Aeronautics and Space Administration (NASA), in cooperation with the biomedical community, particularly researchers from the Massachusetts Institute of Technology (MIT), has initiated work offering significant advances in cell culturing technology on Earth, and enabling research aboard the Space Shuttle,

Mir, and soon an International Space Station. The Biotechnology Cell Science Program at NASA's Johnson Space Center involves more than 100 engineers, scientists, and support personnel.

Lisa Freed and Gordana Vunjak-Novakovic, two researchers at MIT, had been working on tissue engineering for nearly seven years with Robert Langer, the Germeshausen Professor of Chemical and Biomedical Engineering at MIT, when NASA approached them in 1996 about developing a tissue engineering experiment for Mir.

In the experiment, which ran for three months on Earth and then for an additional four months aboard the Space Station Mir, the scientists grew viable cartilage tissue from bovine cartilage cells "seeded" on porous polymer scaffolds. Cartilage was selected because it is hardy and has been studied extensively in the laboratory. Inside a bioreactor, the cells attach to the polymer scaffold and secrete a matrix. Over time, the pores of the scaffold are filled in with matrix, the scaffold biodegrades, and a full tissue is regenerated. The scaffold is there to give the tissue its initial shape.

Key to the experiment's success was a rotating wall vessel bioreactor that supplied the cells with nutrients and gases, and removed wastes so they could regenerate full tissues. The soup can-sized bioreactor spins a cell-filled fluid medium and neutralizes most of gravity's effects to encourage cells to grown in a natural way. Ground tests of the bioreactor yielded three-dimensional tissue specimens approximating natural growth, as opposed to traditional cultures which produced flat, one-cell-thick specimens.

The work paves the way for controlled experiments with human tissues. For example, NASA is very interested in bone, since bones can become brittle in microgravity. These experiments could help scientists understand why human tissues are adversely affected by microgravity, and that, in turn, could lead to the development of measures to prevent such effects. This would be important for the health of astronauts aboard space stations and for long-term voyages in space, such as missions to Mars.

Thanks, in part, to the success of the experiment, the researchers were awarded a contract to develop a more advanced cell-culture unit for the International Space Station. The new system, which will be fully automated, will run up to 24 experiments concurrently and will be able to handle mammalian cells and tissues, plant cells, and microorganisms. The system is also designed to determine how specific characteristics of the space environment affect cells and tissues.

The National Building Museum is located at 401 F Street, NW, Washington, DC 20001. The exhibit runs February 26 through November 8, 1998. For more information, call 202-272-2448.

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