Abstract Body: Introduction: In stroke clots, neutrophil extracellular traps (NETs) promote thrombosis, enhance clot stability, and decrease clot amenability to thrombectomy and thrombolysis.

Objective: We examine the relationship between NET enrichment and clot mechanical characteristics, radiomics, and histological microstructure.

Methods: White blood cells (WBCs) were concentrated from human donor whole blood. Platelet-rich plasma and red blood cells (RBCs) were isolated by centrifugation and mixed with WBCs to produce 0%, 20%, and 40% RBC clot analogs. Lipopolysaccharide (LPS) was added (0μL, 2μL, 6μL into 1mL dH2O) to enrich clots with varying NET amounts. CaCl2 induced clotting. Clots were incubated while rotating at 37°C. Clot analogs were assessed mechanically by uniaxial stretch tester and stress-strain curves, radiomically through high-resolution microCT and radiomic feature analysis, and histologically through whole-slide imaging of H&E-stained tissue and immunofluorescence (Citrullinated Histone Antibody and DAPI counterstain) to quantify NETs. Statistical analysis assessed what mechanical, radiomic, and histological features were significantly different among clots of various NET enrichment. unsupervised clustering was performed on radiomic and histological features to identify signatures unique to NET-enriched clots.

Results: LPS addition produced clots with increasing NET enrichment and microstructural complexity. For fibrin-platelet rich clots (0% RBC), NET enrichment produced significant increase in mechanical stiffness, measured by breaking strength (max load) and Young’s Modulus. For each percent composition, radiomic and histomic profiling clustered clot analogs well by NET-enrichment, with NET-enriched clots demonstrating distinct radiomic and histological feature trends. See Figure 1.

Conclusion: NET enrichment produces mechanically stiffer clot analogs with distinct microstructure, radiomic, and histological profiles.