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Tumor Discovery Glioblastoma treating fields system

Modified Eagle medium (Procell Life Science and anesthetized using isoflurane and secured in a stereotaxic
Technology Co., Ltd.), penicillin-streptomycin (Procell frame. The C6-LUC cells, harvested during their exponential
Life Science and Technology Co., Ltd.), fetal bovine serum growth phase, were prepared at a concentration of 5 ×
(ExCell Bio). The reagents used in the rat experiments 10 cells in 5 µL PBS. The cells were injected into the right
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comprised C6-LUC glioma cells (Cyagen Biosciences), striatum at coordinates 1 mm posterior to bregma, 3 mm
isoflurane (RWD Life Science Co., Ltd.), D-Luciferin lateral to the midline, and 4.5 mm deep from the skull
Potassium Salt (Rhone Reagents), and Sprague-Dawley surface. After injection, the skull was sealed with bone wax,
(SD) rats sourced from Hangzhou Qizhen Experimental and the incision was sutured and disinfected. The rats were
Animal Technology Co., Ltd. All rats were male, aged then returned to the SPF environment for recovery.
between 6 and 8 weeks. Ceramic electrodes were acquired
from the Flexible Bioelectronics Division, Institute of 2.4. TTF treatment
Flexible Electronics Technology of THU. Three days post-injection, TTF treatment was
The instruments used for the electrode test comprised administered. Electrode patches were affixed to the shaved
Bruker D8 Discover X-ray diffractometer (XRD), Zeiss scalp of anesthetized rats, positioned orthogonally to
Sigma 300 scanning electron microscope, and Agilent create intersecting electric fields. The TTF system was
4294A precision impedance analyzer. The instruments activated for >20 h daily, with continuous treatment until
used for the rat experiments comprised stereotaxic day 20. The electric field parameters were set to 2 V/cm
apparatus (Blue Star B/S, Anhui Zhenghua Biological at 200 kHz, matching the in vitro settings. Every 4 days,
Instrument Co., Ltd.), multimode small animal in vivo the electrodes were removed, the skin was disinfected, and
imaging system (AniView 600, Guangzhou Boluoteng fresh electrodes were attached.
Biotechnology Co., Ltd.), small animal anesthesia machine Rats were monitored daily for general health, and
(Model H1670401-200L, RWD Life Science Co., Ltd.), the skin reactions at the electrode sites were recorded.
small animal magnetic resonance imaging (MRI) system Bioluminescent imaging was conducted on days 10, 12,
(7.0T MRI, Bruker Biospin GmbH PharmaScan7016), and 14, 16, and 18 using an in vivo imaging system following
constant-temperature drying oven (Model DHP-9082, intraperitoneal injection of D-luciferin. MRI scans were
Ningguo Shaying Scientific Instrument Co., Ltd.).
performed on day 19 using a T2-TurboRARE sequence
2.2. Cell experiments to confirm tumor size. On day 19, blood samples were
collected for complete blood count and biochemical
Four round glass slides were placed in the TTF cell analysis.
experimental device. Three milliliters of cell suspension
(density 2 × 10 cells/mL) was applied evenly on a slide, and 3. Results
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incubated at 37°C. The TTF-treated group was subjected
to the alternating electric field with specific parameters A block diagram is a graphical representation of a
(field strength and frequency). Control cells received system’s architecture, showing key components and their
no electric field stimulation but were otherwise cultured interactions. It provides a high-level overview of the
under identical conditions. The slides were taken out at system’s functionality, which is crucial for understanding
specified times, and the cells were digested and counted. how different subsystems work together. In this study,
Cell morphology and proliferation rates were recorded at the overall design block diagram of the TTF system is
each time point, and changes in cell density were analyzed shown in Figure 1A, including a Signal Generator, Signal
to assess the effect of TTF on cell growth. Amplifier, and Control Module. The Signal Generator
produces a 200 kHz sine wave, amplified by the Signal
2.3. Rat tumor model Amplifier, and modulated through a Microcontroller Unit-
Rats were acclimatized in a specific pathogen-free (SPF)- controlled Control Module to adjust signal intensity and
grade environment at a controlled temperature of 20 – 26°C frequency for each of the 36 output channels. This modular
and humidity of 40 – 70%, with a 12-h light-dark cycle. design allows independent control over each electrode’s
The rats were provided sterilized corn cob bedding, along output, enabling precise application of electric fields. In
with free access to food and water for 7 days. Following the cell culture experiments, four electrodes are arranged
acclimation, the rats were divided into two groups: the orthogonally, providing alternating electric fields every
control group and the TTF treatment group, with three second, as depicted in the inset of Figure 1A.
rats in each group. A printed circuit board (PCB) is the backbone of
The glioblastoma model 36,37 was established by modern electronic systems, providing mechanical
stereotaxic injection of C6-LUC cells. The rats were support and electrical connections for components. It

Volume 4 Issue 2 (2025) 57 doi: 10.36922/td.7171