The Center for Alternatives to Animal Testing is an academic center affiliated with the Division of Toxicological Sciences in the Department of Environmental Health Sciences of the Johns Hopkins University Bloomberg School of Public Health.
Related Links for CAAT Grants
Previous Grants
Nancy L.R. Bucher, MD
Boston University School of Medicine, Boston, Massachusetts
Bucher and colleagues will investigate the suitability of highly differentiated rat hepatocytes, freshly isolated and cultured suspended spheroidal aggregates, for toxicity testing. The researchers suggest that this system may prove a better model for hepatocytes in vivo than adherent culture systems due to the spheroid's 3-D structure, more normal cell-cell and cell-matrix interactions and avoidance of extraneous matrix components.
A microgravity device developed by NASA, the JSC Bioreactor, will be used to culture tumor cell spheroids. The quality and performance of various hepatocyte systems will be assessed by comparing hepatocyte fine structure (via transmission electron microscopy), extracellular matrix and organization of cytoskeletal elements (via immunofluorescence), responsiveness to growth factor stimulation (determined by DNA synthesis) and cell cycle status and presence of normal liver-specific functions, as measured by Northern and Western blot analysis and nuclear run-on assays.