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Abstract Recent developments in digital light processing (DLP) can advance the structural and biochemical complexity of perfusablein vitromodels of the blood–brain barrier. Here, we describe a strategy to functionalize complex, DLP-printed vascular models with multiple peptide motifs in a single hydrogel. Different peptides can be clicked into the walls of distinct topologies, or the peptide motifs lining channel walls can differ from those in the bulk of the hydrogel. The flexibility of this approach is used to both characterize the effects of various bioactive domains on endothelial coverage and tight junction formation, in addition to facilitating astrocyte attachment in the hydrogel surrounding the endothelialized vessel to mimic endothelial–astrocyte interaction. Peptides derived from proteins mediating cell-extracellular matrix (e.g. RGD and IKVAV) and cell–cell (e.g. HAVDI) adhesions are used to mediate endothelial cell attachment and coverage. HAVDI and IKVAV-lined channels exhibit significantly greater endothelialization and increased zonula-occluden-1 (ZO-1) localization to cell–cell junctions of endothelial cells, indicative of tight junction formation. RGD is then used in the bulk hydrogel to create an endothelial–astrocyte co-culture model of the blood–brain barrier that overcomes the limitations of previous platforms incapable of complex topology or tunable bioactive domains. This approach yields an adjustable, biofabricated platform to interrogate the effects of cell-matrix interaction on blood–brain barrier mechanobiology.
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Control of Astrocyte Quiescence and Activation in a Synthetic Brain Hydrogel
Abstract Bioengineers have designed numerous instructive brain extracellular matrix (ECM) environments with tailored and tunable protein compositions and biomechanical properties in vitro to study astrocyte reactivity during trauma and inflammation. However, a major limitation of both protein‐based and synthetic model microenvironments is that astrocytes within fail to retain their characteristic stellate morphology and quiescent state without becoming activated under “normal” culture conditions. Here, a synthetic hydrogel is introduced, which for the first time demonstrates maintenance of astrocyte quiescence and activation on demand. With this synthetic brain hydrogel, the brain‐specific integrin‐binding and matrix metalloprotease‐degradable domains of proteins are shown to control astrocyte star‐shaped morphologies, and an ECM condition that maintains astrocyte quiescence with minimal activation can be achieved. In addition, activation can be induced in a dose‐dependent manner via both defined cytokine cocktails and low molecular weight hyaluronic acid. This synthetic brain hydrogel is envisioned as a new tool to study the physiological role of astrocytes in health and disease.
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- Award ID(s):
- 1454806
- PAR ID:
- 10457830
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Healthcare Materials
- Volume:
- 9
- Issue:
- 4
- ISSN:
- 2192-2640
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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