Periodic Reporting for period 2 - EVIDENCE (Erythrocytes properties and viability in dependence of flow and extra-cellular environment)
Berichtszeitraum: 2022-01-01 bis 2023-12-31
After exiting the bone marrow, reticulocytes mature to form the highly adapted red blood cells travel through our circulation during their entire lifetime of in average 120 days. Thus, they are in constant move and adapt to their surrounding by shape changes, be it during in high-speed flow or during severe volume adaptations when they squeeze through small capillaries or the slits of the spleen having less than half their own size. While on the move, RBCs have to deal with continuous changes in oxygen tension and pH, have to scavenge reactive oxygen species and need to balance their responses towards the chemical and mechanical challenges.
In contrast, most of the current knowledge about RBCs as well as the diagnostic methods rely on RBCs in relative stasis, such as flux measurements, conventional patch-clamp, calorimetric assays, density centrifugation, atomic force microscopy. In extreme examples, the cells of investigation are even dead like in blood smears, electron microscopy or cyto-spins. Even if cells are on the move like in flow cytometers, they may rest in a drop of liquid. When taken from the circulation, the flow of the RBCs is suddenly absent and (together with the application of anticoagulants) the the RBCs experience a completely different environment that is likely to impair their properties.
The objective of EVIDENCE is the exploration of the properties and behaviour of RBCs under flow conditions and in vivo to understand pathophysiology and to design novel diagnostic devices. Theoretical models will help to understand these RBC properties and will enable the transfer of the gained knowledge into diagnostic devises in general and into the development of a spleen-on-the-chip in particular. Furthermore, we aim to understand the effect of the flow in bioreactors, allowing the efficient production of RBCs in vitro with the goal to produce RBC for transfusion.
In contrast, most of the current knowledge about RBCs as well as the diagnostic methods rely on RBCs in relative stasis, such as flux measurements, conventional patch-clamp, calorimetric assays, density centrifugation, atomic force microscopy. In extreme examples, the cells of investigation are even dead like in blood smears, electron microscopy or cyto-spins. Even if cells are on the move like in flow cytometers, they may rest in a drop of liquid. When taken from the circulation, the flow of the RBCs is suddenly absent and (together with the application of anticoagulants) the the RBCs experience a completely different environment that is likely to impair their properties.
The objective of EVIDENCE is the exploration of the properties and behaviour of RBCs under flow conditions and in vivo to understand pathophysiology and to design novel diagnostic devices. Theoretical models will help to understand these RBC properties and will enable the transfer of the gained knowledge into diagnostic devises in general and into the development of a spleen-on-the-chip in particular. Furthermore, we aim to understand the effect of the flow in bioreactors, allowing the efficient production of RBCs in vitro with the goal to produce RBC for transfusion.
Within EVIDENCE we explored properties and behavior of RBCs in vitro and in vivo. This includes, for example, a completely new understanding of the erythrocyte sedimentation rate (ESR), a general inflammation marker. While the conventional view related the sedimentation speed to the size of formed RBC aggregates, we could show that a percolating colloidal gel describes the process much better. A theoretical model helped us to understand and describe these RBC properties. Furthermore, it enabled us to introduce a lower threshold of the ESR as a diagnostic marker for the neuroacanthocytosis syndrome (NAS). So far, only an upper threshold is established as an inflammation marker. Such we enable the transfer of the gained knowledge into diagnostic tests. In similarity we progressed in the development of an artificial spleen and built and successfully tested microfluidic chips. Furthermore, we increased the understanding of the effect of the flow in bioreactors, allowing a more efficient production of RBCs in vitro with the clear goal to enable their transfusion into patients. To this end we found more cost-efficient replacements for expensive compounds necessary for the in vitro RBC production.
We gained a better understanding of the molecular processes and adaptive responses of RBC to hormonal stimulation as well as to mechanical stress in flow, in particular but not exclusively the role of ion channels in triggering signaling cascades and the regulation and adaptation of their cell volume, e.g. when passing the sinoidal slits in the spleen. EVIDENCE used novel technologies, e.g. the Erysense technology, to explore the capillary flow properties of RBCs from Erythrocyte Concentrates (ECs) intended for transfusion and is in the process to establish quality parameters that impact transfusion medicine and such can contribute to improve public health. This is in line with the goal to develop new diagnostic methods for common and rare forms of anemia and enable a quality control for personalized treatment of these groups of patients.
We gained a better understanding of the molecular processes and adaptive responses of RBC to hormonal stimulation as well as to mechanical stress in flow, in particular but not exclusively the role of ion channels in triggering signaling cascades and the regulation and adaptation of their cell volume, e.g. when passing the sinoidal slits in the spleen. EVIDENCE used novel technologies, e.g. the Erysense technology, to explore the capillary flow properties of RBCs from Erythrocyte Concentrates (ECs) intended for transfusion and is in the process to establish quality parameters that impact transfusion medicine and such can contribute to improve public health. This is in line with the goal to develop new diagnostic methods for common and rare forms of anemia and enable a quality control for personalized treatment of these groups of patients.
A number of developments moved beyond the state-of-the-art and are on their way to develop impact, both socioeconomic and with wider societal implications. First of all is the broad awareness that the natural ‘state’ of the red blood cell is in flow and not in stasis (as in most diagnostic settings). Along this line Erysense, a device which probes single red blood cell capillary flow properties, became commercially available, just after the end of EVIDENCE. It was shown to be a valuable tool for judging red blood cell quality during the storage time of transfusion units and in the process of hemodialysis.
Also, our work for using the slow ESR for diagnostic purposes is in the meantime asked to become a validated method by external hospitals / expert centers.
The in vitro production of red blood cells progressed considerably. These cultured cells are currently in clinical trials.
The RR Mechatronics OxyScan test in increasingly applied in the context of sickle cell disease diagnostics/disease management.
A huge impact is coming from the educates Early Stage Researchers. While the majority of them is still in the process of finishing their PhD, the first ones already defended and started new PostDoc projects!
Also, our work for using the slow ESR for diagnostic purposes is in the meantime asked to become a validated method by external hospitals / expert centers.
The in vitro production of red blood cells progressed considerably. These cultured cells are currently in clinical trials.
The RR Mechatronics OxyScan test in increasingly applied in the context of sickle cell disease diagnostics/disease management.
A huge impact is coming from the educates Early Stage Researchers. While the majority of them is still in the process of finishing their PhD, the first ones already defended and started new PostDoc projects!