Abstract The parent grant of this application is R01HL159427 entitled “Elastic, Degradable Vascular Grafts with Helical Microfibers”. The goal of the parent grant is to design a cell-free degradable graft that the host can transform into an autologous vascular conduit. A major aim of the grant is to investigate host remodeling of long microfibrous grafts in a sheep carotid artery model. We performed five implantations in senescent sheep. We learned that the graft needed to be more robust for clinical translation. The research focus of this supplement application is to eliminate fiber stacking and increase fiber fusion at the junction as means to make the vascular graft more robust. Moreover, the Co-I of the parent grant, Dr. Iwijn De Vlaminck, informed the team of a recent advancement on single cell RNA sequencing in sheep. This will greatly enrich the information we gather from our sheep study. Therefore, the research aspect of this supplement will focus on the following specific aims in the next 3 years: 1. Eliminate fiber stacking and induce fiber fusion at the junctions in the graft. 2. Identify the type and potential origin of the cells populating the grafts in the sheep study using single cell RNA sequencing. The design of electrowritten vascular grafts and the study of host remodeling are key aspects of the parent grant. However, neither the study of fiber stacking and fusion, nor RNA sequencing of the sheep graft is proposed in the parent grant. We recognize these as important elements of the study after the project initiation. The research proposed in this supplemental application was not deleted by the initial review group. Halle Welch, a first year African American Ph.D. student, is very passionate about the vascular graft project. This supplement will increase the participation of minority students in vascular graft research and prepare Halle well for a future in academic research. Thus, this supplement request is consistent with the spirit of a diversity supplement.