Among several other biobased, biocompatible and biodegradable polymers, chitosan appears as a good candidate for human health applications. It is an abundant polysaccharide and shows antibacterial and cytocompatible properties. In this study, we developed two supercritical processes aimed at generating chitosan nanoparticles for their further incorporation in biobased films by extrusion with potential applications in packaging and biomedical devices. As a first step, chitosan nanoparticles were generated using two supercritical CO 2 based processes, in order to minimize the use of organic solvent: (1) Supercritical AntiSolvent process: CO 2 acts as an antisolvent towards an acetic acid aqueous solution of dissolved chitosan in which ethanol was added to enhance the antisolvent effect. The reciprocal miscibility of CO 2 with the solvents induces chitosan supersaturation, which in turn, causes the crystallization of the particles. This process led to chitosan nanoparticles generation with an average size of 378. (2) SCASA: pressurized CO 2 is dissolved into water to lower the pH. This acidification allows the chitosan to be dissolved and the resultant solution is sprayed into a hot air stream. This new process allowed the generation of dried chitosan nanoparticles with a median diameter of 400 nm with less than 10 % particles larger than 1µm.