Synthesis of thermo-sensitive CS-g-PNIPAM/CMC complex nanoparticles for controlled release of 5-FU

In this paper, self-assembled thermo-sensitive polyelectrolyte complex nanoparticles formed from chitosan-graft-poly(N-isopropylacrylamide)/carboxymethyl cellulose (CS-g-PNIPAM/CMC) were prepared for entrapment and release of 5-fluorouracil (5-FU). The morphology and size of the nanoparticles were observed by transmission electron microscopy (TEM) and dynamic light scattering (DLS). The polyelectrolyte complex nanoparticles showed a narrow distribution with an average diameter of about 200 nm. The hydrogen bonding interaction between nanoparticles and 5-FU was determined by Fourier-transformed infrared spectroscopy (FTIR). Increasing temperature or pH of the solutions, a sustained and controlled drug release was observed. The chemical cross-linking was an efficient way to decrease the drug release rate at the initial stage. The novel complex nanoparticles with environmentally sensitive properties are expected to be used in the field of intelligent drug delivery system.