Research Interests

Endochondral bone formation involves several different stages of chondrogenesis that occur in a highly regulated and patterned sequence of stages. Gravitational changes, both an increase and decrease, have been shown to disrupt some of the components that participate in these events.

The Rotating Wall Vessel (RWV) bioreactor was developed by NASA as a device for culturing cells and tissues during spaceflight, and to simulate as far as possible, the culture conditions predicted to occur during experiments in microgravity. Although the total amount of force imposed by gravity on the tissue is not reduced in this system, the perception of the direction of gravity by the cells is continuously changing. This device produces a unique culture environment not found in other culture systems.

We are interested in the mechanisms regulating growth, development and mineralization during chondrogenesis. Our lab uses the RWV as a tool to provide a continuous gravitational disorientation to developing skeletal tissue, and have also used the centrifuge facilities at Ames Research Center to apply excess gravitational forces to these tissues. Our focus is to determine if there are certain stages of chondrogenesis that are enhanced or hindered during culture in the RWV and hypergravity. Matrix synthesis, cell proliferation and gene expression are evaluated.

Our lab is also interested in cartilage nutrition, especially in microgravity when other components of the skeletal system such as bone and muscle, are known to be compromised. We are using a newly developed model system to explore nutrient diffusion in cartilage matrix after exposure to microgravity during parabolic flight, and hypergravity during centrifugation.

Relevant Publications

Klement, B.J ., George, B.J., Young, Q.M., and Spooner, B.S. Tissue Growth and Mineralization in the Rotating Wall Vessel and in Spaceflight Journal of Gravitational Physiology 2005 (in press)

Marshall , C., Flowers, R., Goli, N., Vandromme, M., Paulsen, D., and Klement, B.J. Nutrient diffusion through articular cartilage: development and use of a model system. Journal of Gravitational and Space Biology 2005 (in press)

 Klement, Brenda J ., Young, Q.M., George, B.J., and Nokkaew, M. Skeletal tissue growth, differentiation and mineralization in the NASA Rotating Wall Vessel. Bone 2004; 34: 487-498.

Klement, B. J. and Spooner, B.S. Mineralization and growth of cultured embryonic skeletal tissue in microgravity. Bone 1999; 24:349-359.

Keywords
Microgravity, Spaceflight, Bioreactor, Bone, Cartilage, Mineralization