Description
Aim: To use both a rheometer and the Calon shear device model to mimic the foreign surface and artificial shear introduced to the body by ventricular assist devices (VADs). Methods: For the rheometer model (AR-G2, TA Instruments), discs of biomaterial: diamond-like carbon coated stainless steel (DLC); single crystal sapphire (Sap); and titanium alloy (Ti) were attached to parallel plates. Whole human blood was sheared for 5 min between the discs at 0 s-1 and 1000 s-1. For the Calon shear device, bovine blood was circulated at various different shear rates with and without biomaterial sleeves inserted. Complete cell counts were measured. Leukocyte activation through L-selectin shedding, up-regulation of CD11b, and leukocyte microparticle production were measured with flow cytometry as well as viability. Results: Preliminary data for rheometry (n = 6) as percentage from baseline have shown that shearing on a Sap surface at 1000s-1 significantly reduces the number of total leukocytes compared to 0s-1 (76 ± 22%, p = 0.002). L-selectin expression on neutrophils was decreased significantly in the presence of Sap at both 0s-1 (80 ± 13%, p = 0.03) and 1000s-1 (75 ± 8%, p=0.004). This decrease also occurred with Ti at 1000s-1 on both neutrophils (74 ± 20%, p = 0.003) and monocytes (55 ± 22%, p = 0.02). This correlated with an increased, but not significant, CD11b expression in these samples. Viability of the leukocytes was not affected by the biomaterial nor the shear. Data from the shear device is not available at time of abstract submission. Conclusions: Initial results from the rheometer model indicate that shearing blood on a Sap surface may cause higher levels of leukocyte activation whereas DLC shows minimal activation. This correlates with previous work using biomaterials in a static environment. Ongoing work includes optimising the shear rates and exposure times in both models as well as measuring neutrophil ROS generation, phagocytosis and cytokine release.| Period | Sept 2016 |
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| Event title | XLIII Annual Congress of the European Society for Artificial Organs |
| Event type | Conference |
| Location | Warsaw, PolandShow on map |
| Degree of Recognition | International |