<div class="csl-bib-body">
<div class="csl-entry">Khattab, A., Knafl, S., Schmidt, T., Prado Lopez, S., Schmees, C., Wanzenböck, H., & Zeck, G. M. (2025, July 10). <i>Monitoring chemotherapeutic effects on 3D tumor spheroids using impedance spectroscopy</i> [Poster Presentation]. 13th international Meeting on Neural and Electrogenic Cell Interfacing (MEA 2025), Wien, Austria. http://hdl.handle.net/20.500.12708/225018</div>
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dc.identifier.uri
http://hdl.handle.net/20.500.12708/225018
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dc.description.abstract
The impedance changes in tumor spheroids subjected to chemotherapeutic anti-cancer drugs
provide real-time insights into drug efficacy. Studying tumors at the microscale requires
advanced tools to detect changes at the cellular level. We developed an in-house
microelectrode array (MEA) with interdigitated electrodes (IDE) to increase the electrode
surface for sensitive detection and evaluated the changes upon chemotherapeutic treatments
using these MEAs and appropriate analysis.
Four well MEAs with six IDEs in each well were fabricated by the lithography technique. H460
lung spheroids and HCT-116 colorectal cancer spheroids (~ 200µm diameter each) were
cultivated on the IDEs. The following chemotherapeutic treatments (Cisplatin [50 µM],
FOLFIRI) were applied 24 hours after the spheroids placement. Impedance spectroscopy
using voltage excitation and a spectrum range of 100 Hz to 1 MHz with the 2-Point technique
was performed for 5 days [1]. For the analysis, a modified form of the relative impedance
change equation [2], was employed to yield values ranging from -100% to 100%. The modified
equation is defined as: RI change = [(Zs – Zm) / (Zs + Zm)] * 100%, where Zs and Zm are the
relative impedance with spheroid and medium, respectively, and the maximum relative value
is chosen.
The MEA demonstrated stable impedance measurements and enabled easy detection of
tumor spheroids. FOLFIRI treatment showed a small change in impedance (Fig. 1, panel B).
Despite FOLFIRI having a cytotoxic effect by inhibiting DNA synthesis, the response may be
limited on HCT-116 spheroids, reflecting the chemoresistant nature of these colorectal cancer
cells [3] [4]. On the other hand, Cisplatin induced a significant apoptotic response, reducing
impedance amplitude to around 50% (Fig. 1, panel A). These results were validated with a
viability test conducted at the end of each experiment, reflecting the chemoresistance of HCT116 spheroids against FOLFIRI and the pro-apoptotic effect of Cisplatin on H460 spheroids.
For control validation, H460 cells demonstrated stable impedance between 24 and 48 hours
after placement, followed by a marked decline (Fig. 1, panel C), possibly due to necrotic core
formation associated with their rapid proliferation. In contrast, HCT-116 cells exhibited a
gradual impedance decrease, consistent with a slower growth rate (Fig. 1, panel D).
In conclusion, our study demonstrates that impedance spectroscopy using MEAs with
interdigitated electrodes offers a reliable method to monitor chemotherapeutic effects on tumor
spheroids in real time. The noticeable impedance change observed for Cisplatin and to a
smaller degree for FOLFIRI treatments revealed the capability to differentiate between drug
efficacies. By analyzing relative impedance changes, we successfully quantified drug-induced
cellular effects, with results aligning with viability assays. Our microelectrode-based
bioimpedance platform has proven its capability to resolve the distinct proliferative signatures
of lung and colorectal carcinoma cell lines, confirming its robustness for real-time, long-term
evaluation of chemotherapeutic efficacy. Leveraging this sensitivity, our future studies will
extend this bioelectronic approach to immunotherapeutic regimes, enabling patient-specific
profiling of tumor-immune interactions for personalized oncology.
en
dc.description.sponsorship
FFG - Österr. Forschungsförderungs- gesellschaft mbH
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dc.language.iso
en
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dc.subject
microelectrode array
en
dc.subject
Spheroids, Cellular
en
dc.subject
impedance spectroscopy
en
dc.title
Monitoring chemotherapeutic effects on 3D tumor spheroids using impedance spectroscopy
en
dc.type
Presentation
en
dc.type
Vortrag
de
dc.contributor.affiliation
Medical University of Graz, Austria
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dc.contributor.affiliation
University of Tübingen, Germany
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dc.relation.grantno
895365
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dc.type.category
Poster Presentation
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tuw.project.title
Bioelektronische Plattform für personalisierte Krebstherapie auf der Grundlage von 3D-gedruckten Sphäroiden und von Patienten-abgeleiteten Mikrotumoren
