Emerging Cationic Nanovaccines

Nanovaccines are able to deliver antigen(s) and immunomodulator(s) directly to antigen-presenting cells (APCs) of the lymphatic system. Positive charges improve their uptake by APCs and often drive a Th-1 biased immune response so necessary against infectious diseases caused by intracellular pathogens and cancers. However, cationic compounds often display a dose-dependent toxicity so that systematic evaluation of cytotoxicity against cells in culture is required. After the rapid evolution of nanovaccines against SARS-Covid 2, mRNA vaccines gained much strength and have been designed against several infectious diseases, often relying on cationic components for mRNA protection. Once established the limiting concentration for the cationic compound, cationic nanovaccines perform well eliciting the desired Th-1 improved immune response in most cases. Other valuable approach found in the literature has been the construction of biocompatible nanoparticles (NPs) carrying cationic lipids, polymers or surfactants so that minimization of the concentration for the cationic component led to absence of toxicity. Against cancer, recent constructions of nanovaccines in situ after cancer cell disruption in the presence of adjuvants led to systemic presentation of multiple tumoral antigens yielding, in many instances, prevention of metastasis appearance and conversion of tumors non treatable by immunotherapy into treatable ones.