Description
Red blood cells play a central role in blood flow. Their role in macro- and microcirculation cannot be overstated. Microfluidity in the tiniest capillaries is key to adequate blood supply to organs, tissues, and systems in both healthy and pathological conditions. Microcirculation plays a particularly important role in studying brain circulation, where the capillaries of the arachnoid space are sometimes three times smaller than the red blood cell itself. The specifics of this mechanism are difficult to study in various pathological conditions. However, the more closely a condition is linked to the physical and spatial properties of blood, the more difficult it is to determine the fundamental mechanisms regulating red blood cell behavior. Hemorrhagic shock is one such condition. In hemorrhagic shock, microcirculation is critically disrupted, and the delivery of oxygen and nutrients to tissues due to acute blood loss manifests as the inability of capillaries to adequately support exchange, leading to multiple organ failure. Assessing the state of microcirculation (for example, in the skin) helps monitor the effectiveness of therapy.
Highly controlled studies using microfluidic systems
play an important role in understanding the behavior of red blood cells under the influence of pathogenic environmental factors and in selecting selective protective measures against them.
Studying pathological aggregation and deformation of red blood cells is important. Understanding the mechanism of aggregate formation under conditions of normal and increased viscosity is highly relevant for hemorrhagic shock of varying severity. We used microfluidic chips for red blood cells. These miniature devices reproduce microcirculatory conditions to study the deformability, transport, and properties of red blood cells at a scale that mimics capillaries, allowing for analysis of red blood cells. It turned out that during the first and second stages of hemorrhagic shock, red blood cell deformability remained unchanged, but red blood cells aggregability changed. During the third stage of hemorrhagic shock (the uncompensated stage), red blood cells aggregability and deformability changed dramatically. Assessing the elastic properties of red blood cell is crucial for assessing the degree of oxygen delivery.
Thus, our microcirculation simulation allowed us to assess red blood cell erythrocyte deformability and aggregability, which is crucial for clinically assessing the stage of hemorrhagic shock.
Acknowledgment. This work was supported by Shota Rustaveli National Science Foundation of Georgia (FR-24-389)