Construction of multiple concentration gradients for single-cell level drug screening

Abstract

Abstract Isolation and manipulation of single cells play a crucial role in drug screening. However, previously reported single-cell drug screening lacks multiple-dose concentration gradient studies, which will limit the ability to accurately predict drug performance. To solve this problem, we constructed a multi-concentration gradient generator, in which a Tai Chi-spiral mixer can accelerate the mixing of solution in a short time and then produce a linear concentration gradient. Later, a gradient generator combined with a single-cell capture array was adopted to investigate the effects of single or combined doses of 5-fluorouracil and cisplatin on HepG2 and MCF-7 cells at the single-cell level. The results showed that both drugs were effective in inhibiting the growth of cancer cells, and the combination was more effective for HepG2 cells. In addition, the relationship between biomechanical heterogeneity (e.g., deformability and size) of tumor cells and potential drug resistance at single-cell level was investigated, indicating that small and/or deformable cells were more resistant than large and/or less deformable cells. The device provides a simple and reliable platform for studying the optimal dosage of different drug candidates at the single-cell level and effectively screening single-agent chemotherapy regimens and combination therapies.