Surfactant-free biodegradable polymeric nanoparticles generated from self-organized precipitation route: Cellular uptake and cytotoxicity

Abstract

Surfactant-free biodegradable polymeric nanoparticles (NPs) with uniform sizes were prepared by self-organized precipitation (SORP) method. Size and size distribution of the NPs can be easily tuned by varying the preparation conditions. More importantly, we demonstrate that hydrophobic species, semiconductor nanocrystals, and magnetic NPs can be encapsulated into the polymeric NPs effectively and quantitatively to generate multifunctional hybrid NPs. No surfactant is employed during the preparation process, which is crucial for the formed polymeric NPs to be used in bio-related applications. To evaluate the influence of surfactants on cellular behavior, cellular uptake and cytotoxicity of surfactant-free NPs and surfactant-coated NPs were performed. Our results indicated that surfactant-free NPs could be more promptly and effectively phagocytized by cells in vitro compared to residual surfactant-coated NPs prepared from the emulsion–solvent evaporation method, providing a proof that the surfactant-free NPs have more advantages in cellular uptake and more safety in drug delivery and bio-imaging. Moreover, surfactant-coated NPs inhibited cellular uptake of NPs, and had selective toxicity to melanoma A875 cells rather than human umbilical vein endothelial cells (EVC-304), especially for surfactant polyoxyethylene octyl phenyl ether (Triton X-100) due to the generation of intracellular reactive oxygen species (ROS). The surfactant-free uniform NPs prepared from SORP, combining desirable characteristics of hydrophobic drugs and functional materials, may prove advantageous in simultaneous drug delivery, imaging and magnetic field manipulation applications.