Mechanical Characterization of Fibrin-Based Blood Clot Analogues for Modeling Intracerebral Hemorrhage

Abstract Introduction Intracerebral hemorrhage (ICH) carries high mortality and long-term disability. Development of minimally invasive surgical (MIS) evacuation devices is limited by the lack of reproducible clot analogues that reproduce key mechanical features of human ICH clots. This study evaluates the structural and mechanical behavior of engineered clot analogues benchmarked against patient-derived ICH clots. Methods Clot analogues were formulated at FFP:pRBC ratios of 85:15, 90:10, and 95:5. Microstructure was qualitatively assessed using scanning electron microscopy (SEM), and mechanical behavior was characterized by strain sweep rheology, flow sweep viscosity, and axial compression. Mechanical properties were benchmarked against three patient-derived ICH specimens. Results SEM revealed a transition from cell-dominated (85/15) to fibrin-dominant (95/5) microstructures, with 90/10 exhibiting an intermediate architecture. All analogues demonstrated predominantly solid-like behavior ( G ′ > G ″), with storage modulus increasing from 334.3 ± 55.0 Pa (85/15) to 499.9 ± 140.5 Pa (95/5) ( p = 0.037). Tan δ values overlapped with patient-derived specimens, suggesting similar viscoelastic regimes despite differences in absolute stiffness. Peak viscosity was significantly greater for 85/15 than for 90/10 and 95/5 ( p < 0.001). Compressive stress increased numerically with FFP content but did not differ significantly among formulations ( p = 0.053). Conclusion Fibrin-based clot analogues provide a reproducible and tunable platform for modeling selected mechanical characteristics of ICH clots. The formulations span distinct mechanical behaviors that may support standardized benchtop and cadaveric evaluation of MIS ICH evacuation technologies.