Novocyte system

MCF-7 cancer cells, a cultured medium (DMEM), a fetal bovine serum (FBS), trypsin-EDTA, and bovine insulin were obtained from Invitrogen (Carlsbad, CA, USA). MCF-7 cells (5 × 10⁴ cells/mL) were cultured in 6-well plates at 37 °C and 5% CO₂ for 24 h. Then, the cells were detached with 0.05% trypsin-EDTA and centrifuged at 1000 rpm for 5 min to obtain the cell pellets. The cells were fixed with 4% formaldehyde for 24 h at 4 °C and washed with cold phosphate-buffered saline (PBS). To access cellular surface labeling, the YVO₄:Eu³⁺-NH₂ and YVO₄:Eu³⁺@silica-NH-GDA-IgG nanoparticles were employed and incubated with fixed cells for 2 h. The labelled cells were washed with cold PBS twice before resuspending in PBS for analyzing with a flowcytometry Novocyte system (ACEA Bioscience inc.) and NovoExpress software. The cells were requested for light protection.

Cells were seeded in RPMI‐1640 10% FBS. Next day, they were synchronized through serum deprivation for 16 h and then allowed to re‐enter cell cycle in complete medium. Cells were trypsinized, collected, fixed with cold 70% ethanol and stained with propidium iodide (Sigma‐Aldrich) at 0 and 24 h for cell cycle analysis. Cells were analyzed by flow cytometry on a NovoCyte System and results were processed with novoexpress software (ACEA Biosciences, San Diego, CA, USA).

A cell cycle detection kit (Keygen, Nanjing, Jiangsu, China) was used for cell cycle analysis according to the manufacturer's instructions. Cells were then analyzed using the ACEA NovoCyte system (ACEA Biosciences, Santa Clara, CA, USA).