LAUSR

In-vitro neurovascular unit (NVU) models are valuable for investigating brain functions and developing drugs. However, it remains challenging to recapitulate the native architectural features and ultra-soft extracellular matrix (ECM) properties of the natural NVU. Cell-laden bioprinting is promising to prepare complex living tissues, but hard to balance the fidelity and cell growth. This study proposes a novel two-stage methodology for biomanufacturing functional three-dimensional neurovascular constructs in-vitro with low modulus of ECM. At the shaping stage, a low-viscosity alginate/collagen was printed through an embedded approach; at the culturing stage, the alginate was removed through targeted lysing. The low-viscosity and rapid crosslinking properties provide a printing resolution of ∼10 μm, and the lysis processing can decrease the hydrogels' modulus to ∼1 kPa and adjust the porosity of the microstructure, providing cells with an environment closing to the brain ECM. A 3D hollow coaxial neurovascular model was fabricated, in which the endothelial cells had expressed tight junction proteins and shown selective permeability, and the astrocytes outside of the endothelial layer were found to spread out with branches and directly interact with endothelial cells. The present study offers a promising modeling method for better understanding the NVU function and screening neuro-drugs. This article is protected by copyright. All rights reserved.