Flow in fetoplacental microvessels in vitro enhances perfusion, barrier function, and matrix stability

Abstract

Proper placental vascularization is vital for pregnancy outcomes, but assessing it with animal models and human explants has limitations. Here, we present a 3D in vitro model of human placenta terminal villi that includes fetal mesenchyme and vascular endothelium. By co-culturing HUVEC, placental fibroblasts, and pericytes in a macro-fluidic chip with a flow reservoir, we generate fully perfusable fetal microvessels. Pressure-driven flow is crucial for the growth and remodeling of these microvessels, resulting in early formation of interconnected placental vascular networks and maintained viability. Computational fluid dynamics simulations predict shear forces, which increase microtissue stiffness, decrease diffusivity and enhance barrier function as shear stress rises. Mass-spec analysis reveals the deposition of numerous extracellular proteins, with flow notably enhancing the expression of matrix stability regulators, proteins associated with actin dynamics, and cytoskeleton organization. Our model provides a powerful tool for deducing complex in vivo parameters, such as shear stress on developing vascularized placental tissue, and holds promise for unraveling gestational disorders related to the vasculature.

Label-free phenotyping of human microvessel networks

“…From this refocused 2D image, the vessels are segmented using a U-Net convolutional neural network (CNN) 22 . Segmenting vessels from brightfield poses significant challenges, due in part to the confounding signal originating from other co-cultured cell types (stromal cells herein) and the complex ECM, whose protein composition is heavily remodeled during the process of vessel formation, as we have seen previously by mass spectrometry analysis 23,24 . As a result, heavy contrast variations due to differences in light absorbance across the ECM result in obscuring small vessels and some vessel boundaries (Figure 1B-C).…”

Mammary Microvessels are Sensitive to Menstrual Cycle Sex Hormones

“…Interstitial flow, the movement of fluid through the extracellular matrix of tissues and in between cells, has been shown to promote early vessel formation. [ 13a,22 ] Hence, we employed 3D‐printed fluidic reservoirs developed in our lab, [ 23 ] to establish an intermittent interstitial flow from day 1 onward. A computational fluid dynamics simulation demonstrates flow distributions through the device (Figure S2, Supporting Information).…”