Local delivery of endothelial cell spheroids to promote angiogenesis through novel extracellular matrix mimicking electrospun scaffolds

Abstract

Electrospinning has become a prominent process for fabricating nano‐ to micro‐scale fiber scaffolds for a tissue engineered extracellular matrix (ECM). We have shown that a scaffold formed from blended ethylene‐co‐acrylic acid, polycaprolactone, polyethyleneoxide, polyethylenegycol and powdered milk is compatible with endothelial cells (ECs), supports EC communication and promotes rapid new network growth. Here we aimed to test whether the addition of methylcellulose, a polymer known to enhance EC adhesion, in leiu of powdered milk, can accelerate new network growth from EC spheroids, a pro‐angiogenic cell source. In vitro cytotoxicity testing, conducted with a LDH assay, a MTT assay and a cytotoxicity assay, showed that scaffolds were compatible with and support spheroid growth. VEGF concentration and connexin‐43, caveolin‐1 and VEGFR1 expression were quantified and showed that stable communicative sprouts formed throughout scaffolds and that this was likely mediated by an increased VEGF concentration. We conclude that our novel scaffold is desirable for microvascular tissue engineering and that EC spheroids are viable to promote angiogenesis throughout ECM mimicking scaffolds. Thanks to the NIH.