Laser-induced changes of in vitro erythrocyte sedimentation rate

Effect of Radiotherapy and Low-Level Laser Therapy on Circulating Blood Cells of Rats

Introduction: This study aimed to investigate the effect of low-level laser therapy (LLLT) on the blood cell count when applied to parotid glands of rats irradiated by volumetric modular arc therapy (VMAT). Methods: Thirty-two adult male Wistar rats were used in this study. Samples were randomly assigned to three groups: control group (CG, n = 8), immediate laser group (24 hours) (ILG, n=12), and late laser group (120 hours) (LLG, n=12). The two laser groups were previously subjected to VMAT radiotherapy in a single dose of 12 Gy. LLLT with an AsGaAl laser (660 nm, 100 mW) was applied at three points in the region of the parotid glands, right side, with the energy of 2 J per point (20s, 70 J/cm²) and a spot size of 0.0028 cm² for 10 consecutive days. In the euthanasia, blood samples were obtained by cardiac puncture. The samples from each group were processed by an automatic method and analyzed for erythrogram, leukogram and platelet count values. The data were analyzed by ANOVA and each LLLT time point was analyzed in relation to the control group, with a significance level less than 0.05. Results: Groups using LLLT had higher red blood cell counts, being higher in the LLG (P = 0.000). The hematimetric indices MCV (P = 0.002) and MCH (P = 0.009) were lower than the control group, especially when compared to the group using LLLT 120h after radiotherapy (LLG). White blood cell counts were lower in the groups with radiotherapy and immediate use of LLLT (ILG) (P = 0.011), mainly at the expense of lymphocytes (P = 0.002). Conclusion: The results suggest a potential systemic effect of LLLT, especially on circulating red blood cell counts, regardless of their time of immediate or late use of radiotherapy.

Electric Factors in Wound Healing

Significance: Electric factors such as electric charges, electrodynamic field, skin battery, and interstitial exclusion permeate wound healing physiology and physiopathology from injury to re-epithelialization. The understanding of how electric factors contribute to wound healing and how treatments may interfere with them is fundamental for the development of better strategies for the management of pathological scarring and chronic wounds. Recent Advances: Angiogenesis, cell migration, macrophage activation hemorheology, and microcirculation can interfere and be interfered with electric factors. New treatments with various types of electric currents, laser, light emitting diode, acupuncture, and weak electric fields applied directly on the wound have been developed to improve wound healing. Critical Issues: Despite the basic and clinical development, pathological scars such as keloids and chronic wounds are still a challenge. Future Directions: New treatments can be developed to improve skin wound healing taking into account the influence of electrical charges. Monitoring electrical activity during skin healing and the influence of treatments on hemorheology and microcirculation are examples of how to use knowledge of electrical factors to increase their effectiveness.

In Vitro Biostimulation of Low-Power Diode Pumping Solid State Laser Irradiation on Human Serum Proteins

Objective: This research is conducted to clarify whether the action of low-power diode pumping solid state (DPSS) laser doses modify proteins of normal human blood serum in vitro. Background data: Low-power laser light is considered to act through biostimulation rather than through thermal effects. It was found that low-power laser light biostimulates various biological processes, such as increasing the blood flow within the microcirculation. Methods: Human blood serum samples were carefully collected and divided into five equal aliquots. One of them served as a control (nonirradiated serum) and the other four aliquots were irradiated by DPSS laser at a wavelength of 589 nm with different doses (50, 70, 90, and 110 J/cm²). The electrophoretic migration speeds of each specific protein were measured immediately after irradiation using protein electrophoresis. A paired Student's t-test was used between variables. Results: The protein concentrations were not significantly (p > 0.05) changed by the various doses of DPSS laser comparing with the nonirradiated counterpart. The electrophoretic migration speed of serum proteins was significantly decreased in almost all tested doses relative to the nonirradiated counterpart. Moreover, the irradiation of serum proteins (albumin, alpha1, alpha 2, beta, and globulin) with a laser dose of 70 J/cm² was associated with a significant decrease (p < 0.003, 0.02, 0.002, 0.02 and 0.001, respectively) in protein migration speed compared with the protein migration speed of the control nonirradiated counterpart. Conclusions: Laser light at a wavelength of 589 nm induces processes that lead to decreases in serum protein migration speeds. Globulin protein was found to have the lowest migration speed among the other plasma proteins.

Ionizing Radiation Increases the Activity of Exosomal Secretory Pathway in MCF-7 Human Breast Cancer Cells: A Possible Way to Communicate Resistance against Radiotherapy

Radiation therapy, which applies high-energy rays, to eradicate tumor cells, is considered an essential therapy for the patients with breast cancer. Most tumor cells secrete exosomes, which are involved in cell-to-cell communication in tumor tissue and contribute therapeutic resistance and promote tumor aggressiveness. Here, we investigated the effect of clinically applicable doses of X-ray irradiation (2, 4, 6, 8, 10 Gy) on the dynamics of the exosomes' activity in MCF-7 breast cancer cells. Survival and apoptosis rate of cells against X-ray doses was examined using MTT and flow cytometry assays, respectively. Whereas, the levels of reactive oxygen species (ROS) in the X-ray-treated cells were detected by fluorometric method. The mRNA levels of vital genes involved in exosome biogenesis and secretion including Alix, Rab11, Rab27a, Rab27b, TSPA8, and CD63 were measured by real-time PCR. The protein level of CD63 was examined by Western blotting. Additionally, exosomes were characterized by monitoring acetylcholinesterase activity, transmission electron microscopy, size determination, and zeta potential. The result showed that in comparison with control group cell survival and the percentage of apoptotic cells as well as amount of ROS dose-dependently decreased and increased in irradiated cells respectively (p < 0.05). The expression level of genes including Alix, Rab27a, Rab27b, TSPA8, and CD63 as well as the protein level of CD63 upraised according to an increase in X-ray dose (p < 0.05). We found that concurrent with an increasing dose of X-ray, the acetylcholinesterase activity, size, and zeta-potential values of exosomes from irradiated cells increased (p < 0.05). Data suggest X-ray could activate exosome biogenesis and secretion in MCF-7 cells in a dose-dependent way, suggesting the therapeutic response of cells via ROS and exosome activity.

Low-level laser irradiation at a high power intensity increased human endothelial cell exosome secretion via Wnt signaling

The distinct role of low-level laser irradiation (LLLI) on endothelial exosome biogenesis remains unclear. We hypothesize that laser irradiation of high dose in human endothelial cells (ECs) contributes to the modulation of exosome biogenesis via Wnt signaling pathway. When human ECs were treated with LLLI at a power density of 80 J/cm², the survival rate reduced. The potential of irradiated cells to release exosomes was increased significantly by expressing genes CD63, Alix, Rab27a, and b. This occurrence coincided with an enhanced acetylcholine esterase activity, pseudopodia formation, and reduced zeta potential value 24 h post-irradiation. Western blotting showed the induction of LC3 and reduced level of P62, confirming autophagy response. Flow cytometry and electron microscopy analyses revealed the health status of the mitochondrial function indicated by normal ΔΨ activity without any changes in the transcription level of PINK1 and Optineurin. When cells exposed to high power laser irradiation, p-Akt/Akt ratio and in vitro tubulogenesis capacity were blunted. PCR array and bioinformatics analyses showed the induction of transcription factors promoting Wnt signaling pathways and GTPase activity. Thus, LLLI at high power intensity increased exosome biogenesis by the induction of autophagy and Wnt signaling. LLLI at high power intensity increases exosome biogenesis by engaging the transcription factors related to Wnt signaling and autophagy stimulate.