Cytotoxicity of Silver Nanoparticles on Human Periodontal Ligament Fibroblasts

In this study, we investigated the cytotoxicity of silver nanoparticles (AgNPs), which showed effective antimicrobial performance on Porphyromonas endodontalis (P.e) in the previous research, on human periodontal ligament fibroblasts (HPLFs) and provided a scientific basis for the therapeutic application of AgNPs on periodontitis. Incubated with various concentrations of AgNPs for different time periods, the morphology, proliferation, cell cycle, and the expression of key protein and mRNA of HPLFs were investigated using phase contrast microscope, flow cytometric analysis, western blot and qPCR. The results demonstrated that AgNPs with low concentrations (≤16 μg/mL) had little influence on the proliferation and cell cycle of HPLFs, while AgNPs with high concentrations (32 and 64 μg/mL) significantly altered the morphology, inhibited the proliferation, led to cell cycle arrest at G1/S and induced apoptosis. Therefore, AgNPs showed little side-effect to HPLFs under appropriate concentration, but excessive AgNPs significantly influenced the proliferation and cell cycle and induced apoptosis of HPLFs. It was worthy noted that in the clinical application, AgNPs acted as an effective therapeutic agent for the treatment of periodontitis, but the concentration should be strictly controlled.