Studies of craniofacial development in rotating bioreactors.

Several studies in our laboratory assessed the effect of 3-D culture in various rotating bioreactors on craniofacial development. Initially, mouse first branchial arches were cultured. Molar and incisor development occurred in both upper and lower jaws, but maxilla development was deficient because no brain was present. In a second study using excised whole heads, the oral epithelia fused and teeth did not develop. External structure of the face was obliterated, although internally, eye development was excellent. To preserve both internal spaces and external face structure, subsequent experiments used heads encapsulated in alginate. Teeth developed in these heads, though some interior components were necrotic. Additional experiments used older embryos, with already initiated structures, and less concentrated alginate. Orientation and unreserved identification of structures remain unresolved issues. Future studies will identify structures of interest using transcription factors unique to these structures at particular stages of fetal development.