Chitosan nanoparticles loaded with Eucommia ulmoides seed essential oil: Preparation, characterization, antioxidant and antibacterial properties

Eucommia ulmoides seed essential oil (EUSO) is a natural plant oil rich in various nutrients, which has been widely used due to its unique medicinal effects. However, it is prone to oxidation and rancidity under many adverse environmental influences. Nanoencapsulation technology can protect and slow down the loss of its biological activity. In this study, chitosan nanoparticles (CSNPs) loaded with EUSO were prepared by emulsification and ionic gel technology. EUSO-CSNPs were characterized by Fourier transform infrared (FTIR) spectroscopy, Thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The results confirmed the success of EUSO encapsulation and the encapsulation rate ranged from 36.95 % to 67.80 %. Nanoparticle size analyzer, Scanning electron microscope (SEM) and Transmission electron microscopy (TEM) showed that CSNPs were spherical particles with a range of 200.6–276.0 nm. The results of in vitro release study indicated that the release of EUSO was phased, and EUSO-CSNPS had certain sustained-release properties. Furthermore, EUSO-CSNPs had higher antioxidant and antibacterial abilities than pure EUSO and chitosan, which was verified through free radical scavenging experiments and bacteria biofilm experiments, respectively. This technology can enhance the medicinal value of EUSO in biomedical and other fields, and will provide support for in vivo research of EUSO-CSNPs in the future.