Indicator Cells Assist the Development of Tissue Engineering Products
Anne L. Plant, John T. Elliott, K J. Langenbach
The field of tissue engineering holds great promise. The premise is that living cells can be coaxed to differentiate, organize, and regenerate normal physiological function in diseased and damaged tissues. This outcome will not be achieved, however, without greater knowledge of how the components of the extracellular environment, including implantable biomaterials, influence and direct cellular responses. The intracellular events that occur in response to extracellular signaling molecules are far from completely understood. It is clear that there are many cell signaling pathways that result from engaging integrins and other cell receptors with extracellular molecules. Furthermore, it is clear that there is a high level of intersection between different pathways. While these processes are slowly being unraveled, there is no doubt that the final scheme for intracellular signaling will be an extremely complex one.At the National Institute of Standards and Technology (NIST) a program is underway to use existing knowledge of intracellular signaling to provide clues of how cells are processing information from their surroundings. Cell lines will serve as indicators of cellular genetic response to the materials with which they are in contact. The prototype system currently under development is composed of vascular smooth muscle cells that produce a fluorescent protein when they are in a proliferative state. The gene for Green Fluorescent Protein (GFP) is linked to the gene sequence for the promoter of the protein, tenascin. Tenascin is an extracellular matrix protein that has been found to be expressed in smooth muscle cells that are stimulated to proliferate in response to injury , , . These cells provide the basis of a real-time, live-cell assay for how well a biomaterial elicits a proliferative response in smooth muscle cells. Cell proliferation may be a desirable response in some circumstances, but undesirable in other circumstances, such as in response to the implantation of an aortic stent.This program will allow the development of a number of cell lines that will become fluorescent due to expression of other proteins that are considered markers of a particular cell state, in the way that tenascin is an indicator of smooth muscle cell proliferation. Fluorescent gene markers for inflammation, differentiation, and extracellular matrix remodeling, are among the indicator systems under development. A tool kit can be envisioned that consists of indicator cells containing a fluorescent gene, along with reference materials that elicit expected positive or negative (fluorescent or nonfluorescent) responses from cells by virtue of the signals they provide to the cells. These reference materials are thin films of extracellular matrix proteins, which can be easily and reproducibly fabricated and characterized. Thin films of collagen have been fabricated and characterized in our laboratory , and the appropriate responses of GFP-producing smooth muscle cells to these surfaces have been determined.These cell lines and extracellular matrix protein thin films will assist industry in the development of better biomaterials, by allowing rapid assessment of the response of living cells to their extracellular (e.g. biomaterials) environment.
biomaterials, cell proliferation, diseased and damaged tissues, tissue engineering
, Elliott, J.
and Langenbach, K.
Indicator Cells Assist the Development of Tissue Engineering Products, Biomaterials Forum
(Accessed December 8, 2023)