A 25-Year Retrospective on Bio-Engineering

In a prescient article titled, "Engineering the Cell-System Interface" published in the July/August 1988 issue of BioPharm International, Robert S. Cherry called for the emergence of a new type of engineer who would integrate applied biology and chemical engineering to manipulate the chemistry and physiology of the cell. He proposed that this field be called "biological or cellular engineering." As a father whose daughter now holds bachelor's, master's, and doctoral degrees in biological engineering, I can report that his call was heeded.

DEVELOPMENT

The development of biological engineering (bio-engineering) did not occur in precisely the manner that Cherry expected, but his broad outline was followed. The development of bio-engineering followed multiple paths, some of which led to the emergence of related fields such as biomedical engineering and nanobiotechnology. In these latter fields, mechanical and electrical engineers and material scientists apply their knowledge to the solution of engineering problems in biology or medicine, while the manipulation of the cell is left to bio-engineers.

In its infancy, bio-engineering was practiced in various forms in areas such as food technology, brewing, oenology, applied microbiology, applied biochemistry, and biochemical engineering. Corresponding academic departments often housed small units of engineers who dealt with the interface between machinery and the biological component. Some of these groups developed into independent departments of biological engineering, but a large number found themselves incorporated into existing departments of agricultural engineering. Because "ag-engineering" dealt with whole organisms and their subunits, it was only a short step to dealing with material at the cellular and sub-cellular level. Consequently, there are many departments of agricultural and biological engineering located within colleges of agriculture and life sciences. These bio-engineering programs have attracted a large number of students at the graduate and undergraduate levels.

THE PRESENT

Despite its youth, bio-engineering has been widely applied to areas such as food production, nutritional supplements, bioremediation of sewage, production of biofuels, environmental modification, and the production of drugs and biologics. Early examples of bio-engineering are steroid drugs developed using plants to produce the basic steroid ring structures and bacteria used to remove or modify some of the side chains. These products were then chemically converted into final drug substances. The biological component was used to replace costly or difficult chemical reactions that would have made the drug substances prohibitively expensive.

As with many interdisciplinary fields, there was some resistance from the related disciplines that resented what they considered to be intrusions into their specialties. Some engineers looked upon biologicals as just another type of material and some biologists thought that engineering was just "mechanical stuff." As biochemists and biophysicists had found previously, a blending of the different types of knowledge is necessary. As awareness of the need for this blending spreads, bio-engineers are being more widely accepted for their ability to contribute to the solutions of modern problems.

THE FUTURE

Bio-engineering is still evolving. At first, agricultural engineering dealt with whole organisms and their major subunits, and then bio-engineering began to manipulate whole cells and their products. The next step was, of course, to go to the subcellular level to manipulate the whole cell or its products. Genetic engineering has emerged as a way to modify cells and their products and behavior. Genetic engineering has now been extended to synthetic biology where entire cells may be created by modifying genetic material and physiology to create types of cells that never existed. The bio-engineer who needs cells with particular properties will be able to manipulate existing cells or synthesize new cells that will possess desired properties.

Through the manipulation of genetic, biophysical, and biochemical properties, the bio-engineer will be able to create new types of cellular systems that can replace chemical or biological manufacturing sequences to make useful products from undesirable wastes. Cells have already been isolated or produced that are capable of using sunlight to fix carbon dioxide and produce both biofuels and animal feeds in a single pass. This advancement is only a small example of the vast potential of bio-engineering.