Multidimensional Quantitative Measurement of Cancer Chemoresistance through Differential ZIF‑8 Nanoparticle Cellular Retention

Chemoresistance of cancer cells is conventionally quantified by half-maximal inhibitory concentration (IC50) or multidrug resistance gene 1 (MDR1) values, but these metrics can only reflect the overall drug resistance level of a cancer cell line. Meanwhile, the multidimensional evaluation of both the heterogeneity in a cell line and the drug resistance degree of each cell still presents a daunting challenge. We report here that the cellular heterogeneity, cellular cross contamination, and the proportion of chemoresistant cancer cells can be visualized via flow cytometry through the differential cellular retention of fluorescent ZIF-8 nanoparticles. In addition, we show that the degree of drug resistance exhibited by each cell subpopulation can be quantified by differing fluorescence of the drug-resistant and drug-sensitive cells in the corresponding flow cytometry profile, and the quantified metric S is highly consistent with the MDR1 expression results. Importantly, this novel strategy is applicable to various cancer cell lines, thus demonstrating a universal diagnosis platform for multidimensional, quantitative, and highly efficient diagnosis of cancer chemoresistance.