Low-frequency electromagnetic field influences human oral mucosa keratinocyte viability in response to lipopolysaccharide or minocycline treatment in cell culture conditions

Piezoelectric and Dielectric Electrospun Fluoropolymer Membranes for Oral Mucosa Regeneration: A Comparative Study

Wound healing of the oral mucosa is an urgent problem in modern dental surgical practice. This research article presents and compares the findings of the investigations of the structural, physicochemical, and biological characteristics of two types of polymeric membranes used for the regeneration of oral mucosa. The membranes were prepared from poly(tetrafluoroethylene) (PTFE) and a copolymer of vinylidene fluoride and tetrafluoroethylene (VDF-TeFE) and analyzed via scanning electron microscopy, atomic force microscopy, X-ray diffraction analysis, and Fourier transform infrared spectroscopy. Investigation results obtained indicate that both types of membranes are composed of thin fibers: (0.57 ± 0.25) μm for PTFE membranes and (0.43 ± 0.14) μm for VDF-TeFE membranes. Moreover, the fibers of VDF-TeFE membranes exhibit distinct piezoelectric properties, which are confirmed by piezoresponse force microscopy and X-ray diffraction. Both types of membranes are hydrophobic: (139.7 ± 2.5)° for PTFE membranes and (133.5 ± 2.0)° for VDF-TeFE membranes. In vitro assays verify that both membrane types did not affect the growth and division of mice fibroblasts of the 3T3-L1 cell line, with a cell viability in the range of 88-101%. Finally, in vivo comparative experiments carried out using Wistar rats demonstrate that the piezoelectric VDF-TeFE membranes have a high ability to regenerate oral mucosa.

Low-frequency electromagnetic fields influence the expression of calcium metabolism related proteins in leukocytic cell lines

Our study aimed to verify the hypothesis concerning low-frequency magnetic fields (LF-MFs)-related changes in cell viability through the biomechanism(s) based on calcineurin (CaN)-mediated signaling pathways triggered via ROS-like molecules. For experiments, Mono Mac 6 and U937 leukocytic cell lines were chosen and exposed to various LF-MFs and/or puromycin (PMC). The protein expression level of key regulatory proteins of calcium metabolism was examined by Western Blot analysis. In turn, the reactive oxygen species (ROS) and cell viability parameters were evaluated by cytochrome C reduction assay and flow cytometry, respectively. The simultaneous action of applied MF and PMC influenced cell viability in a MF-dependent manner. The changes in cell viability were correlated with protein expression and ROS levels. It was verified experimentally that applied stress stimuli influence cell susceptibility to undergo cell death. Moreover, the evoked bioeffects might be recognized as specific to both types of leukocyte populations.

A mechanistically approached review upon assorted cell lines stimulated by athermal electromagnetic irradiation

The probable influence of electromagnetic irradiation on cancer treatment has been deduced from the interaction of artificial electromagnetic emissions with biological organisms. Nonetheless, the suspected health effects induced by electromagnetic-based technology imply that such a treatment may contaminate the adjacent healthy cells. Thus, gaining mechanistic insights into the problem is required to avoid athermal health hazards. To tackle that, the current review, based upon in vitro studies into assorted cell lines, depicts the alterations in physiological processes triggered by electromagnetic irradiation via addressing gene regulatory cascades. Furthermore, decisive factors in the hypothesized cause-effect linkage in terms of the cell line-associated, exposure-associated, or endpoint-associated parameters are highlighted. As a result, subcellular structures such as aberrant Ca2+ channels, rich glycocalyx charge, or high water content in cancerous cells, which have attracted a great deal of attention, can explain their higher susceptibility compared with healthy cells under irradiation. Affected by cell components or geometry, the cellular biological window correlates with the metabolic or cell cycle status and determines the irradiation that causes the maximum influence. For instance, correlations between the frequency (or intensity) of irradiation and cell excitability or between the duration of irradiation and cell doubling time are observed. There are unspecified signaling pathways such as the pathway of PPAR-γ or MAPKs, and also proteins devoid of any investigation such as p14, or S phase-related and G2 phase-related proteins. Other chains, such as the cAMP connection with mitochondrial ATP or ERK signaling, the association of Hsps releases with signaling pathways of MAPKs, or the role of different ion channels in regulating various cell processes, require further investigation.

Protein expression changes during phagocytosis influenced by low-frequency electromagnetic field exposure

The aim of our studies was to determine the influence of a low-frequency electromagnetic field (EMF) on the phagocytosis of latex beads (LBs) and the expression level of proteins/genes in the human monocytic macrophage Mono Mac 6 (MM6) cell line in in vitro conditions. Before phagocytosis assay cells were pre-stimulated with infectious agents such as lipopolysaccharide (LPS), Staphylococcal enterotoxin B (SEB), or the proliferatory agent phytohaemagglutinin (PHA), and then exposed to EMF (30 mT, 7 Hz, 3 h). The expression of cytoplasmic proteins like iPLA, cPLA, iNOS, NLR3/4, and Hsp70 involved in the immune response pathways to phagocytosed particles were evaluated with the usage of the Western blot analysis. mRNA encoding the iNOS protein was detected by reverse transcription PCR method. The most meaningful changes were observed for PLA2 and NLC4 proteins level and between iNOS protein expression and mRNA encoding iNOS protein amount. The EMF exposure exerted the strongest effect on iNOS encoding mRNA in cells pre-stimulated with LPS or SEB and phagocytosing LBs. The influence of EMF on phagocytosis was experimentally proved for the first time and there is a need for further investigations in term of the usage of EMF as a prospect, supportive therapy.

Immunity and electromagnetic fields

Despite many studies, the question about the positive or negative influence of electromagnetic fields (EMF) on living organisms still remains an unresolved issue. To date, the results are inconsistent and hardly comparable between different laboratories. The observed bio-effects are dependent not only on the applied EMF itself, but on many other factors such as the model system tested or environmental ones. In an organism, the role of the defense system against external stressors is played by the immune system consisting of various cell types. The immune cells are engaged in many physiological processes and responsible for the proper functioning of the whole organism. Any factor with an ability to cause immunomodulatory effects may weaken or enhance the response of the immune system. This review is focused on a wide range electromagnetic fields as a possible external factor which may modulate the innate and/or adaptive immunity. Considering the existing databases, we have compiled the bio-effects evoked by EMF in particular immune cell types involved in different types of immune response with the common mechanistic models and mostly activated intracellular signaling cascade pathways.