A multicellular spheroid-based drug sensitivity test by scanning electrochemical microscopy.

Area of Science:

• Biomedical Engineering
• Cancer Research
• Analytical Chemistry

Background:

• Assessing anticancer drug efficacy in 3-D spheroid cultures is crucial for predicting in vivo outcomes.
• Traditional methods like spheroid volume measurement may not accurately reflect viable cell numbers.
• Non-invasive techniques are needed for real-time monitoring of cellular responses to drugs.

Purpose of the Study:

• To evaluate the anticancer drug sensitivity of multicellular spheroids using scanning electrochemical microscopy (SECM).
• To compare SECM-based drug sensitivity measurements with conventional assays and spheroid volume.
• To establish the utility of SECM for predicting in vivo drug responses.

Main Methods:

• Multicellular spheroids were cultured and their respiratory activity monitored non-invasively using SECM.
• The effects of cisplatin (CDDP), 5-fluorouracil (5-FU), and paclitaxel (TXL) were evaluated over 5 days.
• Drug sensitivities were compared between SECM, spheroid volume, colorimetric assays, and 2-D/3-D cell cultures.

Main Results:

• SECM-based drug sensitivity measurements correlated directly with viable cell numbers in spheroids.
• SECM showed higher sensitivity compared to spheroid volume measurements.
• Drug sensitivities in 3-D spheroid cultures, assessed by SECM, are more representative of in vivo conditions than 2-D cultures.

Conclusions:

• SECM is a suitable method for directly evaluating drug sensitivity in spheroid cultures.
• SECM provides a more accurate assessment of viable cells than spheroid volume.
• SECM-based assays in 3-D cultures hold promise for predicting in vivo anticancer drug efficacy.