Vaccination faces limitations, and delivery systems additionally appear to have potential as tools to trigger protective immune responses against diseases. The nanoparticles studied are cationic maltodextrin-based nanoparticles with an anionic phospholipid core (NPL); they are a promising antigen delivery system, and their efficacy as drug vectors against complex diseases such as toxoplasmosis has already been demonstrated. Cationic compounds are generally described as toxic; therefore, it is of interest to evaluate the behavior of these NPL in vitro and in vivo. Here, we studied the in vitro toxicity (cytotoxicity and ROS induction in intestinal and airway epithelial cell lines) and the in vivo tolerability and genotoxicity of these nanoparticles administered by the nasal route to a rodent model. In vitro, these NPL were not cytotoxic and did not induce any ROS production. In vivo, even at very large doses (1000 times the expected human dose), no adverse effect and no genotoxicity were observed in lungs, stomach, colon, or liver. This study shows that these NPL can be safely used.