Cytotoxic Effect of Chitosan Nanoparticles on Normal Human Dental Pulp Cells

Introduction: Recent in vitro studies have shown that chitosan nanoparticles could enhance the antimicrobial activity of several dental materials. However, the biocompatibility of these nanoparticles with normal human cells is still controversial. The aim of this study was to evaluate the potential toxicity of various sizes and concentrations of chitosan nanoparticles cultured with normal human dental pulp cells. Methods: Normal human dental pulp cells were derived from human dental pulp tissues and cultured with (50-67) nm and (318-350) nm chitosan nanoparticles in concentrations: 0.2 mg/mL, 0.5 mg/mL, 1 mg/mL, and 2 mg/mL as study groups, and 0 mg/mL as a control. The cell attachment efficiency for each group was assessed at 16 hours. The proliferation rate and cell viability were evaluated at days 7 and 14. Both, attachment efficiency and proliferation rate were assessed by measuring the optical density of crystal violet stained cells. The cell viability was determined by the activity of the mitochondrial dehydrogenase enzyme. Statistical analysis was performed using One-Way ANOVA and post hoc Tukey test. Results: All concentrations of the (50-67) nm group significantly reduced cell attachment efficiency in comparison with the control (p<0.01) and with the (318-350) nm group (p<0.01). All concentrations of both groups, (50-67) nm and (318-350) nm, significantly reduced cell proliferation and cell viability compared to the control in dose-dependent and size-associated manners. (p