Synthesis of thermo-sensitive polyelectrolyte complex nanoparticles from CS-g-PNIPAM and SA-g-PNIPAM for controlled drug release

In this paper, thermo-sensitive polyelectrolyte complex nanoparticles assembled from chitosan-graft-poly(N-isopropylacrylamide) (CS-g-PNIPAM) and sodium alginate-graft-poly(N-isopropylacrylamide) (SA-g-PNIPAM) 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 size distribution. The hydrogen bonding interactions between nanoparticles and 5-FU, which was determined by fourier-transformed infrared spectroscopy (FTIR), increased drug loading. Glutaraldehyde, as a cross-linking agent, reinforced the nanoparticle structure and decreased the burst drug release. When changing temperature, pH, or ionic strength, a sustained and controlled drug release was observed. The novel complex nanoparticles with environmentally sensitive properties are expected to be useful in the field of intelligent drug delivery system.