Abstract 888: Vascular Repair Using Endothelial Cells Derived From Omental Fat
Background: Enhanced reendothelialization following acute vascular injury limits neointimal formation and improves vascular reactivity. Attempts to enhance reendothelialization have included in vivo biological manipulation such as delivery of cytokines to stimulate vascular endothelial growth or direct delivery of cells with an endothelial phenotype. Sources for autologous endothelial cells include vascular and bone marrow derived cells. Here we describe the use of omental fat as an alternative source of endothelium with potential for vascular repair.
Methods: We have established a method to harvest highly proliferative microvascular endothelial cells from rabbit omental fat. Omental fat (3–5mg) was harvested from NZW rabbits through surgical resection. Cells derived from fat were cultured with endothelial cell growth media (EGM-2) following mechanical disaggregation and enzymatic digestion. After 7 days a mean number of 6.4 (± 0.2) million cells were generated in culture. Cells were immunologically and functionally phenotyped. Fat-derived ECs exhibited cobblestone morphology, expressed eNOS and vWF, demonstrated DiI acetylated LDL uptake and did not express smooth muscle specific markers. Following acute balloon injury of the left carotid artery, about 3 million cells were delivered in a group of 20 rabbits. The right carotid artery of 12 rabbits was used as a control and saline was delivered. For both groups the incubation time was 20 minutes.
Results: 48 hours after treatment rabbits were sacrificed following Evans Blue administration. The vessels in which cells were delivered showed almost complete exclusion of Evans Blue while the control vessels were stained entirely blue. A mean coverage of 82.2%( ± 26.9) of the cell treated vessel against 4.2%( ± 3.0) of the untreated vessel (p < 0.001) was shown. Immuno-fluorescence imaging with DiI acetylated LDL demonstrated intraluminal coverage of delivered cells.
Conclusion: Omental fat is a potential source for highly proliferative endothelial cells. These cells provide an autologous source of endothelium to be used to enhance reendothe-lialization after 48 hours for vascular repair. Studies to determine long term effects on vascular structure and function are ongoing.