Electrosprayed sperical ethylcellulose nanoparticles for an improved sustained-release profile of anticancer drug

A solution treated by electrospraying often has a relatively low polymer concentration, thereby overlooking that pure solvent can be used as an additional working fluid. In this study, a modified coaxial electrospraying, characterized by the usage of pure solvent as a shell fluid, was developed to generate nano drug delivery systems for providing the desired drug sustained-release profiles. Ethylcellulose (EC) and tamoxifen citrate (TC) were exploited as a polymer matrix and a poorly water-soluble anticancer model, respectively. Comparing with those particles prepared using a traditional single-fluid process, the TC-loaded EC particles from the modified coaxial processes have a rounder shape, a smaller diameter, and a highly compact inner structure, as demonstrated by the scanning electron microscopic images. Given the favored secondary interactions between TC and EC, all the particles are similarly amorphous composites, as verified by their X-ray patterns and attenuated total reflectance-Fourier transform infrared spectra. Nevertheless, the rounder nanoparticles from the coaxial processes were able to provide a better drug sustained-release profile than their counterparts in terms of smaller initial burst release, longer release time period, and shorter time tailing-off later stage. Both microformation mechanisms of the medicated particles and drug sustained-release mechanisms are suggested. The protocols developed here facilitate the generation of functional nanomaterials from cellulose and its derivatives owing to breaking the traditional concept of electrospraying.