NATIONAL CENTRE FOR SCIENTIFIC
RESEARCH «DEMOKRITOS»
PUBLIC RELATIONS & PRESS OFFICE
Press Release
Athens, 16 November 2012
 

NCSR “Demokritos” researchers employ Nanotechnology techniques for high-precision imaging and study of human blood

 

The optical microscope, today widely used as a diagnostic tool in clinical practice, restricts the observation of biopsy material to the overall morphology of tissue and cell. Trying to analyze in detail structures onto a cell membrane and offer a detailed and more accurate picture of the respective biochemical processes, scientists began to apply innovative imaging techniques based on nanotechnology.


Such techniques, as the Atomic Force and Scanning Electron Microscopes, are applied by NCSR “Demokritos” researchers at the laboratory of “Biomedical studies with imaging techniques of Nanotechnology” with head researcher Dr. Dimosthenis Stamopoulos, in collaboration with Medical Doctors from the Departments of Nephrology, Hemodialysis and Therapeutic Plasma Exchange of the General Hospitals of Athens “G. Gennimatas”, “Alexandra” and “Aretaieion”. The aim of this multidisciplinary research team is to explore what happens to the blood cells of patients with renal, neurological and autoimmune diseases under extracorporeal blood circulation therapies, such as hemodialysis and therapeutic plasma exchange.


A large part of the ongoing research focuses on studying the red blood cells of patients with end-stage kidney disease that are under hemodialysis using the above mentioned nanotechnology-based imaging techniques. Knowing that these patients suffer from chronic anemia, the scientists attempted to record in detail the changes that occur in their red blood cells. Comparing red blood cells of patients to those of healthy donors, the scientists discovered that the membrane of red blood cells of
the patients is strongly defected with extended abnormalities, the so-called “orifices”. The team also counted the number of these “orifices” and found them increased by 59% in patients compared to those of the healthy donors. At the same time, the scientists noticed that the increased number of damaged red blood cells is directly correlated to high levels of urea in the blood. The findings of this research project, which are published in the current volume of Nanotechnology journal, show that high levels of uremic toxins in the blood could be a possible underlying cause of the modification observed in the red blood cell membranes, that ultimately could decrease their lifespan, thus contributing to chronic anemia.


Another important project of NCSR Demokritos research team is to study the possible side effects of the plasma replacement medium that is administered to patients under therapeutic plasma exchange, onto the blood cells and more specifically to red blood cells. Blood, the only fluid tissue in human body, is composed of cells -red blood cells, white blood cells and platelets- suspended in a liquid medium called plasma, which is water that mainly contains dissolved lipids, proteins, carbohydrates and electrolytes. However, when people are suffering from autoimmune, neurological and hematologic diseases, their blood plasma contains harmful antibodies and proteins that need to be removed. In the majority of these cases, the only effective treatment is the therapeutic plasma exchange or plasmapheresis. During this treatment the blood plasma is totally removed and replaced with artificial blood plasma, the so-called replacement medium. Nevertheless, the physiological actions as well as the possible side effects of the replacement medium onto blood cells haven’t been studied yet in detail.

The researchers attempted to cover this knowledge gap employing the previously mentioned nanotechnology-based imaging techniques to the detailed study of the changes that occur in the patients’ blood, when replacement medium is administered. What they discovered was that some plasma replacement media cause crystallization of electrolytes at the periphery of red blood cells, possibly leading to biochemical malfunction, thrombosis and unstable blood pressure. Due to these findings, the research team suggests that the prescription pattern and administration dose of plasmapheresis should be re-examined. They propose that the overall dose and specific composition of the administered “artificial plasma” have to be adjusted to the clinical data (hematocrit etc.) and anthropometric parameters (weight, height etc) of the patient, with an algorithm different from the one used up to now. These findings were presented in May 2012 at 38th Annual Panhellenic Medical Congress, where the research group received a first prize award for best poster.

The scientists that participated in this collaborative research project are: Dimosthenis Stamopoulos (http://www.ims.demokritos.gr/ims_persprofile.php?lang=en&person=66&PHPSESSID=1b192ce433e97f6fb4b8b4e5dfb77911), Vassiliki Gogola, Efthymios Manios and Manos Zeibekis from the Institute of Advanced Materials, Physicochemical Processes, Nanotechnology and Microsystems of the NCSR “Demokritos”, Nikolaos Afentakis and Nerantzoula Bakirtzi from the Department of Nephrology of the General Hospital of Athens “G. Gennimatas”, Dora Stivarou from the Department of Experimental Pathology and Oncology at the University of Florence, Maria Panagiotou from the Department of Nephrology of the General Hospital of Athens “Alexandra” and Eirini Grapsa from the Department of Nephrology of the General Hospital of Athens “Aretaieion”.

Relative links:

Relative Publication: ‘Defected red blood cells membrane and direct correlation with the uremic milieu: connection with the decreased red blood cell lifespan observed in hemodialysis patients’, D. Stamopoulos, E. Grapsa, E. Manios, V. Gogola and N. Bakirtzi, Nanotechnology, 48, 485101 (2012)

http://iopscience.iop.org/0957-4484/23/48/485101

The recent findings of the research group of the laboratory of “Biomedical studies with imaging techniques of Nanotechnology” of the NCSR “Demokritos” were presented at the following congresses:

- 38th Annual Panhellenic Medical Congress (May 16-19, 2012)

The winning poster: Stamopoulos_poster_EN.pdf

- 17th Panhellenic Congress on Nephrology (May 10-13, 2012)

- 49th European Renal Association-European Dialysis and Transplant Association Congress in Paris (May 24-27, 2012)

http://www.postersessiononline.com/173580348_eu/congresos/49era/aula/-FP_456_49era.pdf
http://www.postersessiononline.com/173580348_eu/congresos/49era/aula/-SAP_536_49era.pdf
http://www.postersessiononline.com/173580348_eu/congresos/49era/aula/-FP_460_49era.pdf

- 4th Panhellenic Congress on Therapeutic Apheresis (June 9, 2012)
 
For the N.C.S.R. "Demokritos"

The National Center for Scientific Research (NCSR) "Demokritos" is the largest multidisciplinary research center in the country with substantial scientific research, technological and educational activities in the areas of: Health, Biology and Biotechnology, New Materials Micro & Nanotechnology, Environment - Energy and Sustainable Development, Information Technology & Telecommunications, Nuclear Physics & Elementary Particle Physics, Nuclear Technology & Radiation Protection, Cultural Heritage.

 

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