Drug screening on digital microfluidics for cancer precision medicine

Abstract

Drug screening based on in-vitro primary tumor cell culture has demonstrated potential in personalized cancer diagnosis. However, the limited number of tumor cells, especially from patients with early stage cancer, has hindered the widespread application of this technique. Hence, we developed a digital microfluidic system for drug screening using primary tumor cells and established a working protocol for precision medicine. Smart control logic was developed to increase the throughput of the system and decrease its footprint to parallelly screen three drugs on a 4 × 4 cm² chip in a device measuring 23 × 16 × 3.5 cm³. We validated this method in an MDA-MB-231 breast cancer xenograft mouse model and liver cancer specimens from patients, demonstrating tumor suppression in mice/patients treated with drugs that were screened to be effective on individual primary tumor cells. Mice treated with drugs screened on-chip as ineffective exhibited similar results to those in the control groups. The effective drug identified through on-chip screening demonstrated consistency with the absence of mutations in their related genes determined via exome sequencing of individual tumors, further validating this protocol. Therefore, this technique and system may promote advances in precision medicine for cancer treatment and, eventually, for any disease.

Fig. 1. Schematic of drug screening on digital microfluidics for cancer precision medicine.

Schematic of the digital microfluidic (DMF) system for drug screening of biopsy samples from MDA-MB-231 breast cancer xenograft mouse model and patients with liver cancer.

Fig. 2. Sing drug screening on chip.

a Cell viability results for the biopsy samples from 14 individual mice with different drugs, epirubicin hydrochloride (EP), cisplatin (Cis) and wzb117 (Wzb, the glucose transporter 1 inhibitor) treatment. mouse #1–5, n = 2; mouse #6, n = 3, mouse #7, 8, 10–13, n = 2, mouse #9, #14, n = 1. b On-chip drug screening results for the biopsy samples from 14 mice with Dox (40 μM) or EP (40 μM) or Wzb (40 μM) treatment and the corresponding drug administration mode in vivo. c fluorescence imaging results for the biopsy samples from mouse 6 with different drugs (Cis, EP, Wzb) treatment. Green color represents live cells, red color represents dead cells. “×”, the cell toxicity was not measured due to limited amount of samples. Each experiment was repeated independently for 3 times with similar results. Source data are provided as a Source Data file.

Fig. 3. The process and results of single drug therapy in vivo.

a The process involving breast cancer MDA-MB-231 model establishment, biopsy sample collection, on-chip drug screening, and screening results guided treatment in vivo. b Image of the biopsy needle and biopsy samples collected from the tumor area. c Image of the mouse before and after obtaining a biopsy sample with skin adhesion around the tumor area. d–f The results of mice treatment. The relationship between drug administration times, d tumor volume, and e mouse body weight. f Tumor size after drug treatment. Source data are provided as a Source Data file.

Fig. 4. Combinational drug screening on chip and in vivo therapy.

a On-chip drug screening results for the biopsy samples from 15 mice with Doxorubicin (Dox, 10 μM) or Curcumol (cur, 20 μM) or Dox (10 μM) plus Cur (20 μM) treatment and the corresponding drug administration mode and therapeutic effect in vivo. b Representative on-chip drug screening fluorescent imaging results for the biopsy samples from mouse 4, 9, and 13 after Dox (10 μM) or Cur (20 μM) or Dox (10 μM) plus Cur (20 μM) treatment. Because of the limited biopsy samples, one experiment was repeated for mouse 4 and mouse 13. Each experiment was repeated independently for 2 times with similar results for mouse 9. c, d The results of mice treatment. The relationship between drug administration times andc tumor volume, d mouse body weight. Source data are provided as a Source Data file.

Fig. 5. On-chip drug screening results of four clinical anti-cancer drugs on five patients with liver cancer using a portable Digital Microfluidic (DMF) system.

a Cell viability results of apatinib-treated group derived from patient #3. Live cells were stained with green fluorescence and dead cells were stained with red fluorescence. Each experiment was repeated independently for three times with similar results. b Dose-response results of four commonly used empirical targeted drugs on five patients with liver cancer. Data are the mean of three independent experiments. Source data are provided as a Source Data file.

Fig. 6. Characterization of the biopsy samples from human patients.

a, b Flow cytometry analysis of patients#12, #13, revealed cells with high CD44 but low CD24 expression. c Fluorescence imaging results of the cells obtained from biopsies of patient #9, #10, and #11. Green represents living cells and red represents dead cells. Scale bars are 100 μm. d Cell viability results of the samples from patients #9 (0.83 ± 0.047, n = 14), #10 (0.89 ± 0.04, n = 9), and #11 (0.77 ± 0.07, n = 10). Source data are provided as a Source Data file.