Dried cells, tissues could solve biological materials storage, transport problems

BLACKSBURG, VA March 2, 2001 -- If human tissue could remain viable after being dried, stored, and rehydrated, then life-saving blood products, organs, pharmaceuticals, and sensors could be transported and used virtually anywhere. Now research by Virginia Tech scientists has shown enough promise to land a multi-million grant from the Department of Defense (DoD).

The DoD has awarded Malcolm Potts, professor of biochemistry and director of the Virginia Tech Center for Genomics (VIGEN), a grant for research on biomimetic cell and tissue stasis. The study involves the genetic engineering of human cells to achieve long-term stabilization in the air-dried state and will apply principles of functional genomics and bioinformatics derived from VIGEN's work on extremophile microorganisms currently supported through the Defense Advanced Research Projects Agency (DARPA).

Extremophiles survive extreme conditions of heat, cold, moisture, radiation, salinity, alkalinity, and acidity. Potts and Richard Helm, of the Fralin Biotechnology Center at Virginia Tech, have been studying the cyanobacterium, Nostoc commune, which has the capacity to survive in the dry state for hundreds of years and, upon rewetting, to rapidly recover respiration, photosynthesis, and nitrogen fixation abilities. Nostoc produces a unique biopolymer that protects the cells from heat, desiccation, and ultraviolet (UV) radiation. Potts and Helm have isolated genes involved in these responses for transfer to sensitive cells.

They have dried mouse cells and, most recently, human kidney cells for as long as eight days. The cells are air dried at ambient room temperature. Cell division resumed when the cells were rehydrated.

"This technology could be important to the storage of stem cells, red blood cells, platelets, organs, tissues, and biosensor materials," says Potts. "Storage of such materials presently requires refrigeration, which is a tremendous load for the transport of organs and skin grafts from pharmaceutical companies to hospitals, for example, or the transport of blood products to disaster sites and war zones."

Another application is protein-based sensors being developed to detect biohazards, which presently work in the laboratory but don't often reach the field, says Helm. "This technology will result in more robust biosensors," he says.

Long-term space flight is also a consideration, says Potts. Astronauts may need to carry tissues, organs, and cell lines. " Seeds, biochemicals, and pharmaceuticals could be given almost indefinite shelf life," he says. The world market for biomedically stable products is $500 billion.

The DoD awarded 48 grants to 32 academic institutions as part of the fiscal 2001 DoD Multidisciplinary University Research Initiative (MURI) program, "designed to address large multidisciplinary topic areas representing exceptional opportunities for applications and technology," according to the DoD news release. "The awards provide long-term support for research, graduate students, and equipment purchase supporting research themes vital to national defense."

"The Department of Defense expects that we will create technologies for use in the public and private sector," Potts says.

The award is initially valued at $2.6 million for three years. An additional two years of support ($1.9 million) is also possible, contigent on program success and the availability of funds. Thus the total award is potentially $4.5 million for five years. The researchers are also eligible for proteomics equipment funding ($300,000) and support for up to three MURI graduate research fellows. A competition amongst MURI awardees will be conducted in April for the equipment and research fellow funds.

In addition to Potts and Helm, collaborators are Tom Sitz of biochemistry and Lenwood Heath and Naren Ramakrishnan of computer science, all of Virginia Tech; John Battista of Louisiana State University, Baton Rouge, and Fred Bloom of Invitrogen-Life Technologies of Rockville, Md., as part of the Metabolic Engineering initiative of DoD.

Potts� and colleagues' early work to understand the structural, physiological, and molecular basis for desiccation tolerance in cyanobacteria received university research seed money and earned a $950,000 grant from DARPA in 1998 that allowed them to launch VIGEN. Faculty members from many disciplines, from biology to computer science, use VIGEN's expertise in molecular/genetic manipulation techniques for different projects.

"VIGEN researchers use our understanding of genes to manipulate the cells -- to do metabolic engineering that is technology driven," explains Helm. VIGEN provides a focus for interdisciplinary research and teaching in functional genomics, statistical genetics and bioinformatics, and molecular engineering, he says.

Learn more about the research and VIGEN at http://vigen.biochem.vt.edu/.

PR CONTACT: Susan Trulove
540-231-5646 [email protected]

For more information, contact Dr. Potts at [email protected] or 540-231-5745 or Dr. Helm at [email protected] 540-231-4088.

Recent scientific publications include:
1. Billi, D.,Friedmann, E.I., Helm, R.F. and Potts, M. 2001. Gene transfer to the desiccation-tolerant cyanobacterium Chroococcidiopsis sp. Journal of Bacteriology . in press (April).
2. Hunsucker, S.W., B.A. Tissue, M. Potts and R.F. Helm. 2001. Screening protocol for the UV photoprotective pigment scytonemin. Analytical Biochemistry 288, 227�230.
3. Billi, D., Wright, D. J., Helm, R. F., Potts, M., and Crowe, J. H. (2000). Engineering desiccation tolerance in Escherichia coli. Applied and Environmental Microbiology 66:1680-1684.
3. Billi, D. and M. Potts. 2000. Life without water: Responses of prokaryotes to desiccation. pp. 181-192. In: Storey, K.B. and Storey, JM (Eds) Environmental Stressors and Gene Responses. Elsevier Science BV.
4. Shirkey, B., D.P. Kovarcik, D.J. Wright, G. Wilmoth, T.F. Prickett, R.F. Helm, E.M. Gregory and M. Potts. 2000. Active Fe-SOD and abundant sodF mRNA in Nostoc commune (Cyanobacteria) after years of desiccation. Journal of Bacteriology 182: 189-197.
5. Helm, R. F., Huang, Z., Leeson, H., Edwards, D., Peery, W., and Potts, M. 2000. Structural characterization of the released polysaccharide of desiccation-tolerant Nostoc commune DRH-1. Journal of Bacteriology 182:974-982.
6. Huang, Z., Prickett, T., Potts, P., and Helm, R. F. 2000. The use of the 2-aminobenzoic acid tag for oligosaccharide gel electrophoresis. Carbohydrate Research 328:77-83.
7. Savle, P., Shelton, T. E., Meadows, C. A., Potts, M., Gandour, R., and Kennelly, P. J. 2000. N-(cyclohexane carboxyl)-O-phospho-L-serine, a minimal substrate for the dual specificity protein phosphatase IphP. Archives of Biochemistry and Biophysics 376:439-448.
8. Yeh, D. C., Thorsteinsson, M. V., Bevan, D. R., Potts, M., and La Mar, G. N. 2000. Solution 1H NMR study of the heme cavity and folding topology of the abbreviated chain 118-residue globin from the Cyanobacterium Nostoc commune. Biochemistry 39:1389-1399.
9. Kennelly, P. J. and Potts, M. 1999. Life among the primitives: protein O-phosphatases in prokaryotes. Frontiers in Bioscience 4:372-385.
10. Potts, M. 1994. Desiccation tolerance of prokaryotes. Microbiological Reviews 58:755-805. Additional publications are listed at www.biochem.vt.edu/faculty/potts2.html and www.biochem.vt.edu/faculty/potts.html.