A Novel Reverberation Chamber for In Vitro Bioelectromagnetic Experiments at 3.5 GHz

Abstract

In this study, a mode-stirred reverberation chamber (RC) was designed and proposed for the first time as a cell culture incubator for in vitro electromagnetic waves exposure of adherent cells in tissue culture plates. Typical cell incubators require specific conditions such as temperature of 37°C and humidity rate of 95 % which are challenging conditions for a RC. The chamber was characterized as an RC through an innovative experimental methodology based on the measurements of the S 11 parameter of the emitting antenna. The proposed RC is adapted for in vitro bioelectromagnetic experiments for simultaneous exposure of up to ten tissue culture plates under highly homogeneous exposure conditions at 3.5 GHz, i.e., the mid-frequency band of the 5G telecommunication networks. Results showed that the specific absorption rate (SAR) in the exposed samples extracted from temperature measurements was similar (an acceptable maximum variation lower than 30% was observed) in reason of the homogeneity and the uniformity of the field within the chamber. Specifically, measured SAR values were around 1.5 and 1 W/kg per 1 W of incident power, in 6-well or 96well tissue culture plates used for biological exposure, respectively.

Effects of 5G-modulated 3.5 GHz radiofrequency field exposures on HSF1, RAS, ERK, and PML activation in live fibroblasts and keratinocytes cells

“…at SAR equal to 0 W/kg. A novel exposure system, recently designed and characterized, was used for the first time for cells exposures to 5G-modulated 3.5 GHz signals 34 . The system was based on a cell culture incubator that allowed maintaining the desired biological conditions of 37 °C and 5% CO 2.…”

Evaluation of mitochondrial stress following ultraviolet radiation and 5G radiofrequency field exposure in human skin cells

“…Exposure of cells to 5G‐modulated signals at 3.5 GHz was performed using an innovative reverberation chamber (RC) (Orlacchio et al, 2023), that is, an electrically large cavity made of metallic walls where a homogeneous field distribution was achieved through random mechanical stirring of the field components (Hill, 1998). This is particularly convenient in bioelectromagnetic experiments to ensure a highly homogeneous exposure level regardless of the samples location within the exposure system (Capstick et al, 2017; Ito & Bassett, 1983).…”

“…In this study, a cell culture incubator (150 L; BINDER Gmbh), was converted into an RC to guarantee 24 h in vitro exposure under controlled biological conditions (37°C, 5% CO 2 , and 95% humidity). A detailed description of the system schematically represented in Figure 1a was given in (Orlacchio et al, 2023). The main components are reported hereafter.…”

“…SAR, defined as the electromagnetic power dissipated per unit mass in the exposed sample [W/kg] was used as a metric to quantify the exposure level. Local SAR at the cellular level within an approximate volume of 1 mm 3 was experimentally retrieved from the electromagnetic‐induced heating recorded with a fiber‐optic thermometer (Luxtron One; Lumasense Technologies) (Nefzi, 2021; Orlacchio et al, 2023). To validate experimental local SAR values and access SAR distribution in all the exposed samples, numerical simulations using finite difference time domain (FDTD)‐based electromagnetic methodology (Leveque et al, 1992; Orlacchio et al, 2023) were also performed.…”

“…However, for experiments, the incubator was loaded with the same configuration used for the electromagnetic characterization, that is, four six‐well and six 96‐well TCPs, respectively. Indeed, SAR values may widely vary as a function of the losses in the RC which depend on the quantity of culture medium used to cover cell monolayers (Orlacchio et al, 2023).…”