Interaction peculiarities of red blood cells and hemorheological alterations induced by laser radiation

Thesis event information

Date and time of the thesis defence

Place of the thesis defence

Auditorium L10, Linnanmaa

Topic of the dissertation

Interaction peculiarities of red blood cells and hemorheological alterations induced by laser radiation

Doctoral candidate

Master of Science Ruixue Zhu

Faculty and unit

University of Oulu Graduate School, Faculty of Information Technology and Electrical Engineering, Optoelectronics and Measurement Techniques

Subject of study

Electrical Engineering

Opponent

Professor Shangran Xie, Beijing Institute of Technology (China)

Second opponent

Professor Christian Wagner, Saarland University (Germany)

Custos

Professor Alexey Popov, VTT Technical Research Centre of Finland

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Interaction peculiarities of red blood cells and hemorheological alterations induced by laser radiation

This thesis reports on studies of the fundamental interaction dynamics of human red blood cells (RBC) by optical tweezers (OT) and the application of the OT-based RBC-investigation protocol in facilitating blood photobiomodulation research at a single-cell level. The motivation for the present study arises from the scientific and clinical significance of examining RBC interaction mechanisms as a model for studying general cell interaction in cytological science. Exploring the phenomenon and mechanism of the photobiomodulation of laser radiation on the rheological properties of RBC has a great potential in the field of laser blood therapy.

Interaction dynamics and the role of intercellular interaction time and mutual contact in RBC aggregation and OT-induced disaggregation in autologous plasma are presented as new evidence, clarifying the RBC interaction mechanism. The rheological alterations of RBC induced by laser radiation with various irradiation conditions were thoroughly explored at a single-cell level for the first time to provide a better understanding of the underlying mechanism of photobiomodulation on blood. This study demonstrated the beneficial effects of low-level laser irradiation by a 450-nm wavelength with a radiant exposure below 9.5 J/cm2 of improving RBC deformability and preserving cell shape in a harsh environment. Additionally, irradiated RBC aggregates were easily destroyed by the external influence (i.e., optical force), which could be the flow shearing force in a blood vessel and geometrical resistance by vasculature for in vivo conditions.

The current work is important for optimizing the technique of the OT-based RBC evaluation system. It will contribute to the development of effective approaches for improving blood cell viability and blood microcirculation based on the reported photobiomodulation effects.
Last updated: 16.6.2022