Abstract 177: A Novel Vascular "Ring" Assay for Smooth Muscle Contractility Using Magnetic 3-Dimensional Bioprinting

The current standard for studying pharmacodynamics on vascular smooth muscle contractility is wire myography with ex vivo tissue, which suffers from high cost low throughput, limiting its widespread use. Yet, in vitro alternatives are insufficient, as they are commonly two-dimensional (2D) monolayers on rigid surfaces unlike the soft vasculature. Thus, a rapid, robust in vitro assay is needed that mimics the native three-dimensional (3D) environment, while yielding high data throughput. Towards that goal, we introduce an 3D in vitro assay in which cellularized vascular "rings" are rapidly and magnetically bioprinted. In the assay, cells are incubated with magnetic nanoparticles to render them magnetic, then printed into 3D rings (1.5 x 10^5 cells/ring) in 96-well plates. The rings will then contract or dilate over a short amount of time (<5 h) in a dose-dependent manner visually similar to vessel contraction and dilation (Fig. 1A). This measurement is label-free, meaning that the rings can be experimented...