In the framework of novel medical paradigm the red blood cells (RBC) have a great potential to be used as drug delivery carriers. This approach is required an ultimate understanding of the peculiarities of mutual interaction of RBC influenced by nano-materials composed the drugs. The Optical Tweezers (OT) is the cutting-edge optical technology and widely used to explore mechanisms of cells interaction with the ability to trap non-invasively, manipulate and displace living cells with a notably high accuracy. In the current study, the mutual interaction of RBC with laser-synthesized plasmonic nanoparticles (NP) is investigated.
The laser has biomodulation effects on blood properties thus could regulate the microcirculation. The laser-RBC interaction mechanism is unclear, whereas most studies provide statistical results and lack detailed observations of laser irradiation effects on blood rheology. This study is designated to probe the in vitro effects of 520 nm diode laser irradiation on red blood cells (RBCs) mutual interaction properties in spontaneous aggregation process in autologous plasma by optical tweezers (OTs), with an attempt to reveal the laser-RBC interaction outcomes at a single-cell level. The results preliminarily show that though the laser irradiation statistically inhibited the increase of the size of RBC aggregates compared with the non-irradiating group, the aggregation force between single RBCs increased slightly with the time of irradiation.
Optical Tweezers (OTs) is not only a novelty in laser physics but also an indispensable tool in cell biology studies, especially in the precise manipulation of single living cells and detection of ultra-low intercellular bio-forces. The reversible aggregation of red blood cells (RBCs) strongly influences the blood rheological properties and is critical for blood microcirculation monitoring and therapy. However, the mechanism behind and the factors influencing the aggregation dynamics are still not clear. In this study, the peculiarity of red blood cell interaction was investigated and the potential factors influencing the aggregation process were clarified by optical tweezers. The intercellular interaction force in cell pairs, the role of cell deformation and adhesion time in interaction dynamics, as well as the effects of low-level laser irradiation, were evaluated and discussed.
Despite the extensive studies of different types of nanoparticles as potential drug carriers, application of red blood cells (RBC) as natural transport agents for systemic drug delivery, is considered as a new paradigm in modern medicine and possesses great potential. There is a lack of studies on influence of drug carriers of different composition on RBC, especially regarding their potential impact to the human health. Here, we apply conventional microscopy to observe formation of RBC aggregates and the optical tweezers to assess quantitatively mutual interaction of RBC, incubated with inorganic and polymeric nanoparticles. Scanning electron microscopy is utilized for direct observation of nanoparticles localization on RBC membranes. The experiments performed in a platelet-free blood plasma mimicking RBC natural environment. We show that nanodiamonds influence mutual RBC interaction more antagonistically compared to other nanoparticles, resulting in higher aggregation forces and formation of larger cell aggregates. In contrast, polymeric particles do not cause anomalous RBC aggregation. The results emphasize application of optical tweezers for direct quantitative assessment of mutual interaction of RBC influenced by nanomaterials.
Life sciences that focus on improving the quality and standard of life have attracted worldwide attention in fundamental sciences and have promoted the development of novel tools to reveal the mechanism behind biological activities. Advances in single-cell level methods have further deepened the cell biology study, and helped unravel the different structures and function of living cells on a microscopic and molecular level. Among these methods is the Optical Tweezers (OT), a significant achievement of laser physics, which has been widely applied to understand cell interaction dynamics with the ability to non-invasively trap, manipulate and displace a living cell or part of it with highly accurate positioning of the cells. The reversible aggregation of red blood cells (RBC) that strongly influences the hemodynamic mechanisms and blood microcirculation may serve not only as an indicator of disease, but also as a factor affecting the pathological process. In this study, a two-channel OT system combined with a chopper-modulated laser irradiating system was applied to investigate the RBC aggregation mechanism and to reveal the influence of the low-level pulsed He-Ne laser short-time irradiation on this process. A proportional relationship between the interaction area of RBC and the aggregation force was obtained, verified the applicability of the depletion layer model to the RBC aggregation process in plasma. More importantly, a regulating effect of low-level He-Ne laser irradiation on this process was discovered. A statistically significant decrease (p < 0.05) in RBC aggregation forces was observed following 120 s laser light with 225 Hz pulse frequency. This observation brings new insights into conception of the regulating effects occurring during the laser light interaction with blood.
Optical tweezers (OT) is a unique Nobel Prize winning technology that has been widely used in studying cell interaction dynamics at a single-cell level with highly accurate manipulating of living cells and the ability to detect ultra-low intercellular forces. The reversible aggregation process of red blood cells (RBCs) that strongly influences the blood rheological properties thus being critical for blood microcirculation has long been research studied. However, in spite of plentiful researches dealing with RBC aggregation behavior based on an average response of a large number of cells, the detailed mechanism and the applicability of the two coexistent yet mutually opposed models to this reversible process require additional information. In this study, a two-channel optical tweezers system is utilized to reveal the influence of the cell interaction time (0-300 sec) on the RBC (dis)aggregation dynamics. The results show that for RBC enforced disaggregation in autologous plasma, the longer the two RBCs adhere to each other, the stronger the intercellular interaction is, and the lower the degree that a certain optical pulling force can separate two cells, whereas no significant effect of cell interaction time on RBC aggregation process was observed. This observation indicates that the RBC aggregation and disaggregation in autologous plasma are governed by different mechanisms and that the hysteresis effect, namely the dependence of the disaggregation force on RBC interaction history, is a significant feature that needs special consideration in researches related to the RBC disaggregation process.
As a promising drug delivery system, itself or coupled with red blood cells (RBC), nanoparticles (NP) should be studied in frames of their interaction at the cellular level. Experiments were performed on RBC in autologous blood plasma incubated with different NP – TiO2, ZnO, nanodiamonds and polymeric nanocapsules. RBC aggregates formation in RBC suspension was observed with conventional microscopy, while quantitative interaction force measurements between individual RBC was assessed with optical tweezers. Scanning electron microscopy (SEM) imaging demonstrated NP localization and RBC membrane modifications upon binding with NP. Among tested NP, nanodiamonds caused increasing the size of aggregates in RBC suspensions, RBC interaction force increase and strong membrane surface modifications, comparing to other tested NP and control sample. Nanocapsules do not cause any adverse effects on RBC properties, confirming biocompatibility and applicability for drug delivery purposes. Optical tweezers combined with SEM imaging serves as fast informative assessment of NP effects on RBC.
Nowadays, different types of nano-materials are extensively used as parts or drug carriers that potentially can be developed by red blood cells (RBC). In fact there is a lack of studies of influence of nano-materials of different composition on the RBC and their interaction, especially in regards to hazards to human health. Utilizing conventional use of microscopy, optical tweezers, and scanning electron microscopy (SEM) the interaction of RBC incubated with nano-materials were examined. The results of direct observation of localization of nano-materials on the membranes of RBC show that some nano-materials influence strongly both the cells and mutual RBC interaction, resulting formation of larger cell aggregates.
Spectral Fourier analysis of experimentally acquired velocity time dependencies, V(t), of shuttle endoplasmic motility in an isolated strand of plasmodium of slime mold PhysarumPolycephalum has been realized. V(t) registration was performed in normal conditions and after the treatment by respiration inhibitors, which lead to a complete cessation of endoplasmic motion in the strand. Spectral analysis of the velocity time dependences of the endoplasm allows obtaining two distinct harmonic components in the spectra. Their ratio appeared to be constant in all cases, ν2/ν1=1.97±0.17. After the inhibitors are washed out respiratory system becomes normal, gradually restoring the activity of both harmonic oscillatory sources with time. Simulated velocity time dependences correspond to experimental data with good accuracy.
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