The present disclosure relates to the field of polymer coating. The present disclosure provides improved systems and methods for continuous polymer coating of particles (e.g., nanoparticles). The present disclosure provides for a solid hollow fiber cooling crystallization (SHFCC) technique to continuously coat the nanoparticles with polymer. In certain embodiments, the present disclosure embraces continuous coating of particles from about 1 nm to about 10 microns. A polymer solution containing a suspension of submicron particles flows in the lumen of a solid polymeric hollow fiber, and controlled cooling of the polymer solution allows for polymer nucleation on the surface of the particles, and the precipitated polymer forms a thin film around the particles (the thickness of which can be varied depending on the operating conditions). The systems, methods and assemblies of the present disclosure are easily adaptable for coating nano-sized drug particles as well.
