Impedimetric Toxicity Assay in Microfluidics Using Free and Liposome-Encapsulated Anticancer Drugs

Abstract

In this work, we have developed a microfluidic cytotoxicity assay for a cell culture and detection platform, which enables both fluid handling and electrochemical/optical detection. The cytotoxic effect of anticancer drugs doxorubicin (DOX), oxaliplatin (OX) as well as OX-loaded liposomes, developed for targeted drug delivery, was evaluated using real-time impedance monitoring. The time-dependent effect of DOX on HeLa cells was monitored and found to have a delayed onset of cytotoxicity in microfluidics compared with static culture conditions based on data obtained in our previous study. The result of a fluorescent microscopic annexin V/propidium iodide assay, performed in microfluidics, confirmed the outcome of the real-time impedance assay. In addition, the response of HeLa cells to OX-induced cytotoxicity proved to be slower than toxicity induced by DOX. A difference in the time-dependent cytotoxic response of fibrosarcoma cells (HT1080) to free OX and OX-loaded liposomes was observed and attributed to incomplete degradation of the liposomes, which results in lower drug availability. The matrix metalloproteinase (MMP)-dependent release of OX from OX-loaded liposomes was also confirmed using laryngopharynx carcinoma cells (FaDu). The comparison and the observed differences between the cytotoxic effects under microfluidic and static conditions highlight the importance of comparative studies as basis for implementation of microfluidic cytotoxic assays.

A compact multifunctional microfluidic platform for exploring cellular dynamics in real-time using electrochemical detection

“…Aside from diverse applications, such as toxicological evaluation, 15,48 EIS monitoring functions as a tool to assess cell adherence 15 on electrodes in preparation for further bioassays, such as exocytosis detection from cell populations. PC12 cells were seeded using suspensions with different cell densities (from 1.5 to 3 million cells per mL) in order to nd an optimal density, which gives uniform cell coverage on the WEs.…”

Label-Free Bioelectrochemical Methods for Evaluation of Anticancer Drug Effects at a Molecular Level

“…Impedimetric assays were performed to investigate the effects of anticancer drugs on different tumor-derived cell lines. Doxorubicin (DOX), an anthracycline-based antibiotic widely used in the treatment of a broad range of solid tumors, as well as acute leukemia and malignant lymphoma, has been used in many reports as a model molecule for studying the effect of dose or time dependency on a specific cell population density [12][13][14], as well as to distinguish cell models of acquired drug resistance [15]. Table 1 summarizes some examples of anticancer drugs that have been evaluated by impedance-based methods.…”

Microfluidic Cell Chips for High-Throughput Drug Screening

“…For instance, adherent cells detaching from the substrate surface due to causes changes in the impedance. Based on this principle, a label-free and real-time measurement could be performed during drug screening and toxicity testing [54][55][56]. Although this detection approach shows potential for real-time, nonoptical, high-throughput detection that circumvents the need for an automated microscope stage, its requirement of cell type (only suitable for adherent cells) and highly customized circuit design may limit its translation.…”