Carboxymethyl chitosan/ionic liquid imidazolium-based nanoparticles as nanocarriers for zinc phthalocyanine and its photodynamic activity

New nanocarriers have contributed to develop the so-called third-generation photosensitizers for use in the photodynamic therapy (PDT). In this paper, nanoparticles based on carboxymethyl chitosan (CMC) and a monocationic ionic liquid imidazolium-based (IL) (1-dodecyl-3-methylimidazolium bromide, C12MIMBr), loaded with photosensitizer zinc phthalocyanine (ZnPc) was developed for application in PDT. The CMC/IL@ZnPc nanoparticles were characterized by their physicochemical properties, photodynamic activity and drug release profile, and while their performances were compared with those containing conventional surfactants. The polymeric nanoparticles display a nanometric hydrodynamic radius, low polydispersity index, negative zeta potential, high drug loading and encapsulation efficiencies higher than 98%. Moreover, CMC/IL@ZnPc nanoparticles have the ability to produce cytotoxic singlet oxygen (O-1(2)) and the values of singlet oxygen quantum yields (Phi(Delta)) are appropriated for application in PDT. In vitro release kinetic of ZnPc from nanoparticles exhibited a sustained release profile controlled by diffusion, without burst effect. Our findings highlight that CMC/IL-based nanoparticles have potential to be employed as nanocarriers for hydrophobic photosensitizers in PDT. (C) 2021 Elsevier B.V. All rights reserved.