One of NASAs missions is to develop noninvasive models for monitoring the potentially deleterious effects of microgravity on human cell/tissue functions. Previous work has shown that gravitational changes can modify a variety of host cell-matrix interactions. Angiogenesis, an essential process for tissue growth and regeneration, is a coordinated process of activated endothelial cell proliferation and differentiation controlled by specific matrix and growth factor signals. However, little is known about the human angiogenesis process in microgravity, primarily due to the lack of defined functional models. We have created a new human biomatrix (Amgel) culture system which supports endothelial cell growth and function. This unique biomatrix simulates human cell morphogenesis only in the presence of specific modulators (FGF, VEGF). We now propose to employ this natural matrix to further develop an all-human angiogenesis model adaptable for microgravity studies. Endothelial cell cultivation models with controllable bioactivity utilizing Amgel-layered disk and microbead configurations will be evaluated in rotary culture systems. New 3-D bioassays, generated with GF-enriched matrix, would allow examination of both early mitogenic and late angiogenic events. This R&D proposal should positively impact the fields of wound healing, tissue engineering and vascular disease.