Abstract
A comparatively straightforward approach to accomplish more physiological realism in organ-on-a-chip (OoC) models is through substrate geometry. There is increasing evidence that the strongly, microscale curved surfaces that epithelial or endothelial cells experience when lining small body lumens, such as the alveoli or blood vessels, impact their behavior. However, the most commonly used cell culture substrates for modeling of these human tissue barriers in OoCs, ion track-etched porous membranes, provide only flat surfaces. Here, we propose a more realistic culture environment for alveolar cells based on biomimetically microcurved track-etched membranes. They recreate the mainly spherical geometry of the cells' native microenvironment. In this feasibility study, the membranes were given the shape of hexagonally arrayed hemispherical microwells by an innovative combination of three-dimensional (3D) microfilm (thermo)forming and ion track technology. Integrated in microfluidic chips, they separated a top from a bottom cell culture chamber. The microcurved membranes were seeded by infusion with primary human alveolar epithelial cells. Despite the pronounced topology, the cells fully lined the alveoli-like microwell structures on the membranes' top side. The confluent curved epithelial cell monolayers could be cultured successfully at the air-liquid interface for 14 days. Similarly, the top and bottom sides of the microcurved membranes were seeded with cells from the Calu-3 lung epithelial cell line and human lung microvascular endothelial cells, respectively. Thereby, the latter lined the interalveolar septum-like interspace between the microwells in a network-type fashion, as in the natural counterpart. The coculture was maintained for 11 days. The presented 3D lung-on-a-chip model might set the stage for other (micro)anatomically inspired membrane-based OoCs in the future.
Original language | English |
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Pages (from-to) | 2684-2699 |
Number of pages | 16 |
Journal | ACS Biomaterials Science and Engineering |
Volume | 8 |
Issue number | 6 |
Early online date | 3 May 2022 |
DOIs | |
Publication status | Published - 13 Jun 2022 |
Bibliographical note
Funding Information:The following financial support is acknowledged: D. Baptista, S.v.R., T.P., A.A.P., D.S., R.J.R., P.S.H., and R.T., the Lung Foundation Netherlands (project “Microengineered 3D analogues of alveolar tissue for lung regeneration”; no. 6.1.14.010); D. Baptista, L.M.T., and C.v.B., the European Union/Horizon 2020 European Research Council Advanced Grant (project “ORCHESTRATE – Building complex life through self-organization: from organ to organism”; ID 694801); Z.T.B., P.H., S.G., and R.T., the European Union/Interreg Flanders-The Netherlands (project “Biomat on microfluidic chip”, no. 0433); J.K., A.C., S.G., and R.T., RegMed XB (REGenerative MEDicine crossing Borders) powered by Top Sector Life Sciences & Health (Health ∼ Holland); R.J.R. and R.T., The Netherlands Organisation for Health Research and Development (ZonMw)/COVID-19 MKMD Programme (project “Employing a physiological microfluidic lung bioreactor to improve understanding of SARS-CoV2 biology and testing of therapeutics”; no. 114025011); A.C., C.v.B., P.H., S.G., and R.T., the Dutch province of Limburg (program “Limburg INvesteert in haar Kenniseconomie/LINK”; nos. SAS-2014-00837 and SAS-2018-02477); A.C., C.v.B., P.H., S.G., and R.T., The Netherlands Organization for Scientific Research (NWO)/Gravitation program (project “Materials-driven regeneration: Regenerating tissue and organ function with intelligent, life-like materials”; no. 024.003.013).
Publisher Copyright:
© 2022 American Chemical Society.