Fluorescent Polysaccharide Nanogels for the Detection of Tumor Heterogeneity in Drug-Surviving Cancer Cells

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.

Cell Coding Arrays Based on Fluorescent Glycan Nanoparticles for Cell Line Identification and Cell Contamination Evaluation

Cell lines are applied on a large scale in the field of biomedicine, but they are susceptible to issues such as misidentification and cross-contamination. This situation is becoming worse over time due to the rapid growth of the biomedical field, and thus there is an urgent need for a more effective strategy to address the problem. As described herein, a cell coding method is established based on two types of uniform and stable glycan nanoparticles that are synthesized using the graft-copolymerization-induced self-assembly (GISA) method, which further exhibit distinct fluorescent properties due to elaborate modification with fluorescent labeling molecules. The different affinity between each nanoparticle and various cell lines results in clearly distinguishable differences in their endocytosis degrees, thus resulting in distinct characteristic fluorescence intensities. Through flow cytometry measurements, the specific signals of each cell sample can be recorded and turned into a map divided into different regions by statistical processing. Using this sensing array strategy, we have successfully identified six human cell lines, including one normal type and five tumor types. Moreover, cell contamination evaluation of different cell lines with HeLa cells as the contaminant in a semiquantitative analysis has also been successfully achieved. Notably, the whole process of nanoparticle fabrication and fluorescent testing is facile and the results are highly reliable.

Effect of Starvation in Reversing Cancer Chemoresistance Based on Drug-Resistance Detection by Dextran Nanoparticles

Introduction

Chemoresistance leads to chemotherapy failure in patients with cancer. Multidrug resistance (MDR) in cancer is mainly caused by the high expression of P-glycoprotein encoded by the MDR1 gene, which is an ATP-dependent protease. Keeping the stronger invasion and migration abilities of chemoresistant cells in cancer also requires more ATP consumption. Herein, we aimed to reverse resistance by reducing the glucose supply in the cellular environment.

Methods

A starvation approach in reversing chemoresistance was applied, which was implemented through preparing fluorescent dextran-based nanoparticles to detect the proportion of chemoresistant cells in the chemoresistant/chemosensitive cell mixture after cells cultured in a low-glucose condition.

Results

Chemoresistant cells had higher glucose consumption with higher ATPase expression and stronger glucose dependence compared to chemosensitive cells. Moreover, cancer cells cultured in a low-glucose condition reduced the proportion of chemoresistant cells.

Conclusion

Starvation therapy can be used as a new method to reverse drug resistance in cancer.