Design and fabrication of a microplatform for the proximity effect study of localized ELF-EMF on the growth ofin vitroHeLa and PC-12 cells

Abstract

This paper presents a platform technology with experimental results that show the scientists and biologists a way to rapidly investigate and analyze the biological effects of localized extremely low frequency (ELF) electromagnetic field (EMF) on living cells. The proximity effect of the localized ELF-EMF on living cells is revealed using the bio-compatible microplatform on which an on-glass inductive coil array, the source of the localized ELF-EMF in micro scale, is designed, fabricated and operated with a field strength of 1.2 ± 0.1 mT at 60 Hz for cell culturing study. After a 72 h ELF-EMF exposure, HeLa (human cervical cancer) and PC-12 (rat pheochromocytoma) cells exhibit about 18.4% and 12.9% cell proliferation rate reduction, respectively. Furthermore, according to the presented dynamic model, the reduction of the proliferation can be attributed to the interference of signal transduction processes due to the tangential currents induced around the cells.

A thermodynamic approach to the ‘mitosis/apoptosis’ ratio in cancer

“…Indeed, a large number of studies have been carried out to investigate the effects of electromagnetic fields in biological systems [36][37][38][39][40][41][42][43][44][45][46][47][48][49]. Relevant in vitro studies can be summarized as:…”

“…For instance, it has been reported that electromagnetic fields disturb the cancer cells' bioactivity, with a consequent abnormal cell signal transduction process, and that they change the ionic motion (K + , Na + , Ca 2+ and Cl − ) across the cell membrane. Indeed, the oscillating motion of ions near the cell membrane could exert significant voltage fluctuations in the voltage-gated channels leading to a disturbance in the signal transduction process and, consequently, to the inhibition of cell growth [41]. Moreover, several in vitro experiments have pointed out that a 1 h exposure to a 50 Hz, 22 mT magnetic field yields an increase in the intracellular Ca 2+ concentration [57,58], which in turn changes the endonuclease activity.…”

The Gouy-Stodola Theorem in Bioenergetic Analysis of Living Systems (Irreversibility in Bioenergetics of Living Systems)

“…a) Human cervical cancer and rat pheochromocytoma cells show a 18.4% and 12.9% decrease, respectively, in cell proliferation when exposed continuously for 72 h to amagnetic field of 1.2 ± 0.1 mT, at 60 Hz [142]; b) Human cervical cancer cell proliferation decreased by 15% 24 h after being exposed to a magnetic field of 0.18 T, at 0.8 Hz, for 16 h [143]; c) Human colon adenocarcinoma cells decrease their growth when exposed to 1 Hz for 6 h [144]; and, in vivo: a) Exposure of nude mice bearing a subcutaneous human colon adenocarcinoma (WiDr), to 5.5 mT static magnetic fields for 70 min of exposure a day resulted in a significant increase of survival time, a significant inhibition of tumour growth, a reduction of cell proliferation and an increase of apoptosis in tumours of treated animals [145]; b) Male Fischer-344 rats, subjected to the modified resistant hepatocyte model exposed to 4.5 mT at 120 Hz electromagnetic and magnetic fields showed inhibition of preneoplastic lesions [146].…”

“…Indeed, in order to live, cells need temperature differences in relation to their environments; for example, for Streptococcus faecalis it results around 0.4 °C · cm −1 [133]. As a consequence of the experimental results we can state that [133][134][135][136][137][138][139][140][141][142][143][144][145][146][147][148]: a) This temperature difference depends on the cell lines; b) For any cell line, this temperature difference depends on the cells' metabolism.…”

Electromagnetic waves and living cells: A kinetic thermodynamic approach

“…Now, introducing the electro-chemical affinityà = A+Z φ related also to pH variation 14 and the electric field variation, with A j = Σ k ν kj µ j , Z the electric charge per unit mass, φ the electrostatic potential;15 and τ i , i ∈[1, 5], are the lifetimes of any process and:16 1. the chemical potential gradient can be approximated through the ratio between the mean value of the chemical potential 17 µ = 1.20 × 10 −9 J kg −1 and the mean density is considered as ρ = 1000 kg m −3 ;18 2. τ 1 is the time related to the thermal flow driven by temperature difference. It can be assessed considering that the time 19 constant of the thermal transient for heat conduction is τ cv ≈ ρcV /(hA) with ρ ≈ 1000 kg m −3 density, V the cell 20 volume, A the external cell surface, c ≈ 4186 J kg −1 K −1 specific heath, and h the convection heat transfer coefficient 21 evaluated as h ≈ 0.023Re 0.8 Pr 0.35 λ/L, where λ ≈ 0.6 W m −1 K −1 of heat conductibility, L the characteristic dimension 22 of the cell (here we have considered the diameter), Re ≈ 0.2 the Reynolds number and Pr ≈ 7 the Prandtl number.…”