Effect of polysaccharide nanocrystals on structure, properties, and drug release kinetics of alginate-based microspheres

[Display omitted] ► Polysaccharide nanocrystals were firstly introduced into alginate microspheres. ► Mechanical strength and drug release behavior were enhanced and regulated. ► Nanocrystals increased the stability of the crosslinked network structure. ► Release kinetics and transport mechanisms were analyzed and recognized. Polysaccharide nanocrystals, such as rod-like cellulose nanocrystals and chitin whiskers and platelet-like starch nanocrystals, were incorporated into alginate-based nanocomposite microspheres with the aim of enhancing mechanical strength and regulating drug release behavior. The structures and properties of the sols and the resultant nanocomposite microspheres were characterized by rheological testing, Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The presence of polysaccharide nanocrystals increased the stability of the crosslinked network structure, and the nanocomposite microspheres consequently exhibited prominent sustained release profiles, as demonstrated by inhibited diffusion of theophylline. Furthermore, based on the drug release results, the release kinetics and transport mechanisms were analyzed and discussed.