Tales of two chemical and biological engineers

Charles Brown (circa 1943) (36K JPG)

Charles S. Brown (PhD '46) and Paul B. Conrad (PhD '00): Their stories illustrate the important and longstanding role that chemical engineers have played in the life sciences, as well as the evolution of that role over time. Chuck was among a small cadre of chemical engineers who took up careers in the life sciences in the 1940s, while Paul is one of a growing legion of chemical engineers doing so today.

As an undergraduate chemical engineering student at Virginia Polytechnic Institute, Chuck was introduced to the study of microbiology while working on a senior project on the use of low-level radiation to mildew-proof burlap for sandbags. His faculty mentor on that project received a letter from E.B. Fred, then Dean of the UW Graduate School, seeking a graduate student with an interest in biology and engineering. Chuck applied for and was offered a full fellowship to UW beginning in September 1941. He majored in chemical engineering working with Olaf Hougen, and developed a split minor in biochemistry and bacteriology. During his first year at UW, he studied problems in maintaining sterility of valves used in the fermentation industries.

Then the U.S. government, through the new Office of Scientific Research and Development, initiated a wartime project to promote industrial production of penicillin. "It was a mammoth undertaking involving several universities and most of the major pharmaceutical companies," says Chuck.

At the time, penicillium mold was cultured in Petri dishes, shallow pans, or rolling bottles to assure an adequate supply of oxygen. While such technologies are suitable for research and small-scale production, dramatically boosting antibiotic production required a new approach. Chuck shifted his research and found himself as the only engineer working on a project to develop a pilot plant using a 100-gallon stirred vessel for "deep culture" of the mold, and to determine the optimum conditions for penicillin production.

The project moved so quickly, and the major pharmaceutical companies were so desperate for experienced personnel, that by 1944, even before he could finish his degree at Wisconsin, Chuck was hired to work in the newly formed Fermentation Products Department at Abbott Laboratories. Two years later, after he completed work on the first 4,000-gallon production vessel at Abbott, he was granted two months leave to return to Wisconsin to finish his dissertation. He continued with Abbott for his entire 37-year career, achieving the position of Executive Vice President, Administration and earning, among other honors, the 1979 UW-Madison College of Engineering Distinguished Service Citation. In "retirement," Chuck has served as President of the Clara Abbott Foundation, which provides financial assistance to Abbott employees and their families.

Paul Conrad (23K JPG)

Paul Conrad works at Stratatech Corporation, a new UW spin-off located in Madison that is developing a patented line of human skin cells for treating severe burns and chronic wounds such as diabetic ulcers and bedsores. The cell line arose from a spontaneous mutation while UW Professor of Pathology Lynn Allen-Hoffman was conducting basic research on human skin tissue. The cell line has the unique ability to grow and divide indefinitely in vitro, while otherwise developing the normal tissue architecture of skin and behaving normally when grafted to experimental animals. "Because the cell line is 'immortal,' our scientists can make permanent additions or deletions to the cell's genome to address specific wound-healing problems, such as the poor blood flow associated with ulcers," according to Paul.

Like Chuck Brown years ago, Paul is a lone engineer among biologists. Also like Chuck, Paul is working to scale-up production of a biological product from Petri dishes to large tanks. "As an engineer, I am the only person here who is continually focused on developing a production process that is cheaper, faster and more efficient," says Paul.

But for Paul, this scale-up effort involves established technology (thanks, in part, to Chuck's work). His principal research evolved from work as a student in Juan de Pablo's group. At UW, Paul held a fellowship through the campus Biotechnology Training Program and worked to develop and improve processes for cryopreservation of biological materials (see the related story in this issue). Beginning with fundamentals, he developed computer models of the behavior of the cryoprotectant trehalose in freezing water. From this theoretical work, Paul and others in the research group went on to study cryopreservation of bacterial cells, working with Rhodia, a manufacturer of probiotics (see On These Foundations, Spring/Summer 2001, available at www.engr.wisc.edu/che/newsletter/2001_springsummer/).

It was through the Biotechnology Training Program that Paul met Dr. Allen-Hoffman who immediately recognized the importance of developing a method to preserve her cultured skin in order to make it readily and economically available in a clinical setting. Paul established a research project in her lab and began doing consulting work for Stratatech before accepting a permanent position upon graduation. "It has been exciting," says Paul. "I was able to begin with fundamentals — doing molecular simulations — before moving to work with bacterial cells, mammalian cells, and now whole human tissues. Throughout these studies I've always kept a mindset of 'selling' my work to the biologists, which ultimately benefits everyone."

For his part, Chuck Brown says, "I am really impressed with what I see in Madison and Virginia Tech. Multidisciplinary work was not common in the mid-1940s, but it is the order of the day now."