Synthesis and Degradation Study of Cationic Polycaprolactone-Based Nanoparticles for Biomedical and Industrial Applications

Positively charged polymers have increased in importance in the last years because of the possibility of being used in many different applications, from gene delivery to polymer flooding applications and as flocculants in wastewater treatment. In all cases, the possibility of obtaining biodegradable colloidal products leads to great advantages. In this work, positively charged nanoparticles (NPs) have been produced via free radical emulsion polymerization (FREP). This synthetic route was selected since it is widely used in industry and it facilitates large scale production along with control of some key features of the final NPs such as their size, surface charge, and particle size distribution dispersity. NP synthesis was carried out by a four-step process: the synthesis of biodegradable ester-based macromonomers obtained through the ring-opening polymerization of the ε-caprolactone, the reaction among the obtained macromonomer and succinic anhydride, the final condensation with choline chloride to obtain the positively charged macromonomer, and the FREP polymerization of the produced macromonomer. The effects of reaction conditions on NP characteristics were studied, and the tunable behavior of the obtained charged NPs has been proven, also in terms of degradation time.