Micropatterning transcriptionally and phenotypically reprograms endothelial cells.

Vascular occlusions are a major cause of cardiovascular disease and require interventions including graft bypass surgery; yet, the development of synthetic vascular grafts remains a challenge due to the inability of synthetic biomaterials to support an anti-immunogenic endothelium. Topographical micropatterning of biophysical cues offers a promising strategy to enhance graft endothelialization. As the interface between the biomaterial and blood, endothelial cells provide a bioactive interface which regulates inflammation. We utilized topographical micropatterning of polyurethane biomaterial to induce endothelial cell elongation and alignment and measured the resultant transcriptional changes using bulk RNA-sequencing. Cell phenotype was characterized by gene and protein expression as well as chemokine secretion. The biomaterial micropatterning-modulated elongated and aligned morphology promoted an anti-inflammatory transcriptome, reduced pro-inflammatory chemokine secretion, and induced the transcription coregulator yes-associated protein (YAP) phosphorylation, supporting the anti-immunogenic properties of endothelial cells. Cytoskeletal regulation of this anti-immunogenic phenotype was quantified through measurement of intermediate filament vimentin regulation of YAP localization and endothelial pro-immunogenic gene expression. Aggregation of vimentin was positively correlated with YAP dephosphorylation and suppressed proinflammatory gene expression, indicating that endothelial elongation and alignment influence gene regulation and cellular function independent of vimentin-mediated mechanisms. The ability of micropatterned endothelial cells to maintain their anti-immunogenic functions under pro-inflammatory conditions was demonstrated by the increased phosphorylation of YAP and decrease in pro-inflammatory IL-8 release. Our study highlights the potential of biomaterial cues to regulate endothelial cell behavior for vascular graft design. STATEMENT OF SIGNIFICANCE: We used topographical micropatterning to separate the role of endothelial monolayer morphology from unidirectional blood flow and test how architecture alone regulates gene programs. Micropatterned substrates produced a reproducibly elongated, aligned endothelium with coordinated modeling of the vimentin intermediate filament network. Bulk transcriptomics revealed a distinct morphology-associated expression state, including reduced inflammatory signaling and altered secretory profiles, alongside shifts in mechanosensitive regulatory programs and downstream transcriptional signatures. Together, these findings link cytoskeletal organization to endothelial mechanotransduction and highlight biomaterial topography as a design lever to tune endothelial function for preclinical and clinical applications.