Angiogenic outgrowth from a perfused vascular explant: design and implementation of a perfused vascular explant bioreactor

Abstract

This project is concerned with in vitro assays of angiogenesis and how mechanical stimuli are controllably incorporated into them. The vascular explant assay is considered the most physiologically realistic in vitro angiogenesis assay, but it lacks the mechanical stimuli engendered in blood flow. In this thesis, I describe development and implementation of a perfused vascular explant bioreactor to facilitate long-term culture and angiogenic outgrowth from a perfused vascular explant (e.g., mouse thoracic aorta) in vitro. The mouse aorta was subjected to a flow rate that would generate shear stress comparable to that experienced in post capillary venules. Finite element analysis of the reactor predicted perfusion of the aorta lumen would also cause perfusion of the abluminal space, provided the aorta contained holes through with fluid could exit. The vascular explant bioreactor developed in this study supported long-term culture of a perfused and/or perfusible thoracic aorta in vitro, and also demonstrated angiogenic outgrowth from the explant. When the aorta lumen was loaded with fluorescent microspheres, regions of the angiogenic outgrowth fluoresced, suggesting that some of the nascent vasculature was patent to the aorta. The device designed in this study may allow researchers to investigate the interaction between hemodynamic stimuli and angiogenesis in an in vitro model that recapitulates nearly all of the mechanisms and steps of angiogenesis.