Effect of Surface Modification of Silver Nanoparticles on the Proliferation of Human Lung Squamous Cell Carcinoma (HTB182) and Bronchial Epithelial (HBE) Cells In Vitro

Stable silver nanoparticles (AgNPs) were formed in vitro by reacting AgNO₃ (aq) solution with the water soluble polymers PEI and PEG. TEM images indicate a visible layer surrounding the AgNPs (10–35 nm). The toxicity of the AgNPs to HTB182 lung cancer cells and normal human bronchial epithelial (HBE) cells at 2, 4, 8, 10, 20, 30, 40 and 50 μg/mL was assessed using a Cell Counting Kit-8(CCK-8) method and optical microscopy. The results show that the toxicity of AgNPs to HTB182 and normal HBE cells was dose dependent and more prominent in the cancer cells. Then, the effect of AgNPs and silver ions on cell apoptosis and cell cycle distribution in HTB182 and HBE cells was determined by flow cytometry. The results showed that the surface modification of the AgNPs greatly affected their anti-cancer/anti-proliferative properties. The inhibitory effect of PEI-AgNPs on tumor cells was stronger than that of PEG-AgNPs. Treatment with AgNPs or silver ions led to HBE cell arrest in G0/G1. Non-small cell lung cancer HTB182 cells were arrested in G2/M phase due to DNA damage. Therefore, the mechanism of action of silver ions and AgNPs in normal HBE cells is different from that in lung cancer cells.