Trypsin edta

Minimum essential medium (MEM, KeyGEN BioTECH, containing penicillin-streptomycin) with supplement of fetal bovine serum (FBS, Gibco, 10%) and trypsin-EDTA (0.25% w/v) were used to culture and detach the human cervical carcinoma (HeLa) cells (KeyGEN BioTECH), respectively. MoS₂ NSs, MP NSs, MPP NSs, and MPPI NSs suspended in MEM (no FBS, 200 μL/well) were added into HeLa cells that grew in 96-well plates. After incubation for 24 h, the lactate dehydrogenase (LDH) from the supernatant was detected using the LDH-cytotoxicity colorimetric assay kit (BioVision) and the cytotoxicity of nanosheets was evaluated following the instruction described in our previous work (Zhang et al., 2017 (link)). A microtiter plate reader (PowerWave XS2, BioTek) was used to measure the optical density at 495 nm (OD495).

The C17.2 neural progenitor cells was purchased from Bnbio Biotechnology (Beijing, China). For routine cultures, the C17.2 cells were seeded in 75 cm² cell culture bottle. The medium components are H‐DMEM supplemented with 10% fetal calf serum, 100 U penicillin/ml and 100 μg streptomycin/ml. Using 0.05/0.02% trypsin/EDTA (KeyGEN Biotechnology, Nanjing, China) to digest the 80–90% confluent cells and seeded in a new cell culture bottle.

The Caco-2 human intestinal cell line, Dulbecco’s modified Eagle medium (DMEM), penicillin–streptomycin, and trypsin-EDTA (0.25%) were purchased from Jiangsu KeyGen BioTech (Nanjing, China). Hank’s balanced salt solution (HBSS) and fetal bovine serum (FBS) were purchased from Gibco (NY, USA). CAT, GSH-PX, and GR antioxidant enzyme kits were purchased from Nanjing Jiancheng Bioengineering Institute. The primers for real-time PCR were synthesized by Genscript Biotechnology Co., Ltd. (Nanjing, China). Total RNA, and cDNA synthesis kits were purchased from Takara Bio. Inc. The peptide fraction of DLEE (98% purity) was synthesized by China Peptides Co. (Suzhou, China).