Early morphology observation of human periodontal fibroblast cell line in the presence of human salivary exosomes

Human salivary exosomes have been identified as a highly informative nanovesicle with clinical-relevant information for variation of diagnostic purposes. As a continued effort from previous studies on human salivary exosomes effect at gene expression level, this study is carried out to observe the morphology of human periodontal fibroblast (HPdLF) treated with exosomes cells under the same period of changes in genotypic level occurred. In vitro, HPdLF cells were cultured for 24 hours with 10 µg/ml of human salivary exosomes. The morphology of HPdLF cells was examined under inverted light microscopy and scanning electron microscopy (SEM) for both control samples and samples treated with human salivary exosomes, while the cell count was performed via trypan blue staining. There was no significant difference in the morphology under the inverted light microscopy and the cell number of HPdLF cells for both treated and untreated cells with exosomes. However, for SEM, the treated HPdLF with salivary exosomes showed slight observable changes on the filopodia, lamellipodia, cytoplasmic vesicles and the cytoskeleton of the cells. Even within a short period (24 hours) of culturing time for cells with human salivary exosomes, the samples showed minimal changes which positively suggested a simultaneous event of exchanging materials from human salivary exosomes to cells had occurred, hence, potentially proving that human salivary exosomes can enhance cell proliferation.