Unravelling the roles of texture and basal lamina composition on the endothelialization of biomimetic type I collagen matrices
Résumé
Understanding cell-surface interactions on the luminal surface of arteries is key for the development of vascular grafts, as proper endothelialization is critical to hinder thrombosis. In vivo, the basal lamina lines the luminal surface of arteries and is mainly composed of two intertwined collagen IV and laminin networks. It provides biological and mechanical cues favoring endothelial cells’ adhesion, proliferation, and activity, essential for blood vessels’ integrity. Beyond composition, the nanometer or micrometer scale topography of basal lamina also regulates cell morphology and activity [1,2]. However, the effect of these two major factors—composition and topography—on endothelialization remains entangled and little tools are available to decorrelate their respective effects. Here, highly concentrated macroporous type I collagen constructs mimicking accurately the extracellular matrix of blood vessels were produced through ice templating followed by topotactic fibrillogenesis [3,5]. We used this new biomimetic model of the arterial wall extracellular matrix to evaluate the combined effect of composition and topography on the surface of biologically relevant substrates [6]. To that end, we have fabricated materials that feature two different topographies: a smooth surface on one side and a textured one with ridges and grooves on the opposing surface. Each of these surfaces was coated with basal lamina proteins: laminin, fibronectin, or collagen IV. Surfaces and coating deposition were characterized by scanning electron microscopy and confocal microscopy. To gain insights on cell-surface interactions, materials seeded with bovine aortic endothelial cells were observed with fluorescent and confocal microscopy. We observe endothelial cells’ adhesion on the surfaces, and their higher ability to produce VE-Cadherin and therefore form a tight monolayer on a smooth surface, regardless of the coating. Besides, we notice that unidirectional micrometer scale patterns induce a preferential orientation of the cells. Quantitative results on cell density, metabolic activity and proliferation over time enable for the first time to decorrelate the role of topography and composition on biomimetic substractes, suggesting that the coatings favor endothelial cells’ metabolism. The obtained results open an exciting pathway to enhance endothelialization of biomimetic materials for vascular tissue engineering and gain control over colonization kinetics regulated by topography. [1] C. Leclech, C. F. Natale, A. I. Barakat, J Cell Sci 2021, 133. [2] M. Moffa, A. G. Sciancalepore, L. G. Passione, D. Pisignano, Small 2014, 10, 2439. [3] C. Rieu, C. Parisi, G. Mosser, B. Haye, T. Coradin, F. M. Fernandes, L. Trichet, ACS Appl Mater Interfaces 2019, 11, 14672. [4] C. Parisi, B. Thiébot, G. Mosser, L. Trichet, P. Manivet, F. M. Fernandes, Biomater Sci 2022, 10, 6939. [5] I.Martinier et al., Biomater Sci, 2024 [6] M. Bouabdallah, I. Martinier, A. Castagnino, A. Barakat, M. Miyara, L. Trichet, F. Fernandes, in preparation 2024.