Lin, Ruei-ZengLee, Chin NienMoreno-Luna, RafaelNeumeyer, JosephPiekarski, BreannaZhou, PingzhuMoses, MarshaSachdev, MonishaPu, WilliamEmani, SitaramMelero-Martin, Juan2018-01-182017Lin, R., C. N. Lee, R. Moreno-Luna, J. Neumeyer, B. Piekarski, P. Zhou, M. A. Moses, et al. 2017. “Host non-inflammatory neutrophils mediate the engraftment of bioengineered vascular networks.” Nature biomedical engineering 1 (1): 0081. doi:10.1038/s41551-017-0081. http://dx.doi.org/10.1038/s41551-017-0081.http://nrs.harvard.edu/urn-3:HUL.InstRepos:34651811Notwithstanding remarkable progress in vascular network engineering, implanted bioengineered microvessels largely fail to form anastomoses with the host vasculature. Here, we demonstrate that implants containing assembled human vascular networks (A-Grafts) fail to engraft due to their inability to engage non-inflammatory host neutrophils upon implantation into mice. In contrast, unassembled vascular cells (U-Grafts) readily engage alternatively polarized neutrophils, which in turn serve as indispensable mediators of vascular assembly and anastomosis. The depletion of host neutrophils abrogated vascularization in U-Grafts, whereas an adoptive transfer of neutrophils fully restored vascularization in myeloid-depleted mice. Neutrophil engagement was regulated by secreted factors and was progressively silenced as the vasculature matured. Exogenous addition of factors from U-Grafts reengaged neutrophils and enhanced revascularization in A-Grafts, a process that was recapitulated by blocking Notch signaling. Our data suggest that the pro-vascularization potential of neutrophils can be harnessed to improve the engraftment of bioengineered tissues.en-USJournal Article2018-01-1810.1038/s41551-017-0081