The objective of this study was to compare the antitumor activity of lipophilic bismuth nanoparticles (BisBAL NPs) and chlorhexidine (CHX) on human squamous cell carcinoma. BisBAL NPs were synthesized by colloidal method and characterized by energy dispersive X-ray spectroscopy in conjunction with scanning electron microscopy (EDS-SEM). The effect of BisBAL NPs and CHX on oral cancer cell line (CAL-27) and nontumor control cell human gingival fibroblasts (HGFs) was determined by MTT cell viability assay. The obtained results showed selective inhibition of CAL-27 cell growth by BisBAL nanoclusters. A 24h exposition to 25
M BisBAL NP decreased 91% of CAL-27 cell growth, while nontumor HGFs cells were unaffected by BisBAL NPs showing 90% of cell viability. In contrast, CHX kills both CAL-27 and HGFs with the same efficacy. 25 M of CHX decreased 97% and 80% of tumor and nontumoral cell growth. BisBAL NP and CHX alter cell permeability suggesting that action mechanism may include loss of cell membrane integrity. Also, CHX and not BisBAL NP presented genotoxicity on genomic DNA of tumor cells. As conclusion, BisBAL NPs have a selective antitumor activity on human squamous cell carcinoma, unlike CHX which was cytotoxic for both tumoral and nontumoral control cells.