Slow Freezing Coupled Static Magnetic Field Exposure Enhances Cryopreservative Efficiency—A Study on Human Erythrocytes

Abstract

The aim of this study was to assess the cryoprotective effect of static magnetic fields (SMFs) on human erythrocytes during the slow cooling procedure. Human erythrocytes suspended in 20% glycerol were slowly frozen with a 0.4-T or 0.8-T SMF and then moved to a −80°C freezer for 24 hr. The changes in survival rate, morphology, and metabolites of the thawed erythrocytes were examined. To understand possible cryoprotective mechanisms of SMF, membrane fluidity and dehydration stability of SMF-exposed erythrocytes were tested. For each test, sham-exposed erythrocytes were used as controls. Our results showed that freezing coupled with 0.4-T or 0.8-T SMFs significantly increased the relative survival ratios of the frozen-thawed erythrocytes by 10% and 20% (p<0.001), respectively. The SMFs had no effect on erythrocyte morphology and metabolite levels. However, membrane fluidity of the samples exposed to 0.8-T SMF decreased significantly (p<0.05) in the hydrophobic regions. For the dehydration stability experiments, the samples exposed to 0.8-T SMF exhibited significantly lower (p<0.05) hemolysis. These results demonstrate that a 0.8-T SMF decreases membrane fluidity and enhances erythrocyte membrane stability to resist dehydration damage caused by slow cooling procedures.

Impact of Inhomogeneous Static Magnetic Field (31.7–232.0 mT) Exposure on Human Neuroblastoma SH-SY5Y Cells during Cisplatin Administration

“…The magnetic field imposes its effect in an agonistic or antagonistic manner, depending on induction, duration, and physicochemical condition of the microenvironment. These include: i) pH by carbon dioxide hydration [47] – [48] ; ii) nanobubble formation [49] ; iii) zeta potential [49] ; iv) ionic strength and salt mobility that act oppositely at high and low salt concentrations [50] ; and v) decrease [51] and increase [8] in membrane permeability. Thus, the matter should be addressed per case, according to the status applied.…”

Pheophytin a Inhibits Inflammation via Suppression of LPS-Induced Nitric Oxide Synthase-2, Prostaglandin E2, and Interleukin-1β of Macrophages

“…Pheophytin a (C 55 H 74 N 4 O 5 ), a chlorophyll-related compound [ 16 ], is an important component of green tea. It has anti-inflammatory [ 17 ], anti-oxidant, and anti-chemotactic properties in human polymorphonuclear neutrophils [ 18 ], and anti-hepatitis C activity and functions in anti-tumor promotion. Because sepsis is a dysregulated inflammatory response, drugs that could modulate the production of inflammatory mediators might be useful to treat inflammatory diseases and endotoxin shock.…”

Iridoids of Chemotaxonomy Relevance, a New Antirrhinoside Ester and Other Constituents from Kickxia spuria subsp. integrifolia (Brot.) R.Fern.

“…To the best of our knowledge, it has not been recognized before in species belonging to the Plantaginaceae family, being more common to find in algae and crops such as green tea leaves, parsley, bellpepper, and Japanese bunching onion . Compound 1 is known to exert several interesting pharmacological properties such as the antioxidant, antiviral, anti‐inflammatory, antichemotactic, antihepatitis C, and antitumor ones …”