Green synthesis, characterization and in vitro release of cinnamaldehyde/sodium alginate/chitosan nanoparticles

As a natural preservative, cinnamaldehyde (CA) has a bright application prospect. However, CA is sensitive to light and can be easily oxidized. What's more, its water solubility is poor. These properties greatly limit its application. In this study, CA/sodium alginate (SA)/chitosan (CS) nanoparticles (CA/SA/CS NPs) were prepared by using SA and CS as wall materials, and CA as core material. The single factor experiment showed that the optimal CA/SA/CS NPs can be obtained when the mass ratio of SA to CS was 5.5/1, SA to CaCl2 was 5/1, SA to CA was 1/2, and the pH of CS solution was 5.0. Under this condition, the average size of the prepared nano-particles was 455.2 nm, polymer dispersity index (PDI) value was 0.189, zeta potential was -40.8 mV, and the encapsulation efficiency was 72.92%. The scanning electron microscopy (SEM) and atomic force microscopy (AFM) images confirmed the formation of nanoparticles, which were spherical or ellipsoidal in shape. The fourier transform infrared spectroscopy (FTIR) and multifunctional polycrystalline X-ray diffraction (XRD) spectra indicated that CA was encapsulated in the nanoparticles. Furthermore, in vitro release experiments showed that CA/SA/CS NPs had the function of sustained release. In summary, SA/CS NPs can be used as a promising carrier for CA.