Over the past 5-10 years, a number of studies have demonstrated that vasculature formed in bulk gels in vitro can inosculate (connect) with host vasculature in vitro following transplantation.  These pre-vascularization strategies hold great promise to treat ischemic conditions and potentially overcome a critical challenge in the field of tissue engineering.  However, they require an invasive surgery, which in some cases may not be desirable.  In collaboration with Jan Stegemann (UM BME), we are making small vascularized modules by embedding endothelial cells and supportive stromal cells in small biomaterial modules (on the order of 250-400 um in diameter) and culturing them for a period of time to allow the cells to self-assemble into primitive vascular networks. The small microtissues can then be injected in a minimally-invasive fashion, thereby jump-starting the formation of microvasculature in vivo.