Nanoparticles based on carboxymethylcellulose-modified rice protein for efficient delivery of lutein

Lutein, as a natural nutrient, has many benefits for human health. However, its poor chemical stability and low bioavailability limit the application of lutein in foods. The aim of this study is to design and develop rice protease hydrolysate (RPH)-carboxymethylcellulose (CMC) nanocarriers for efficient delivery of lutein. RPH-CMC nanoparticles were prepared by heating at a ratio of RPH to CMC of 4 : 1 and pH of 6.0 (70 degrees C, 20 min). The structure of the nanoparticles was characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD) and transmission electron microscopy (TEM). In addition, the stability, in vitro release characteristics, anti-proliferation and drug absorption of lutein-loaded rice protein nanoparticles (Lut-R) and lutein-loaded CMC-RPH nanoparticles (Lut-R-C) were evaluated. The results of in vitro release showed that compared with Lut-R, Lut-R-C could effectively slow down the release of lutein in the stomach (19.55 +/- 1.71% and 8.10 +/- 0.41%) and accelerate its release after entering the small intestine (76.64 +/- 1.47% and 96.07 +/- 0.71%). In addition, RPH-CMC nanoparticles had good biocompatibility, and Lut-R-C nanoparticles could effectively inhibit the proliferation of breast cancer cells (MCF-7) with inhibition rate of 70% in a dose-dependent manner when lutein concentration was 20 mu M. It was found that lutein uptake rate and amount in Lut-R-C treated cells were always higher than that in Lut-R treated cells. The absorption of Lut-R-C by Caco-2 cells was 90.8 times higher than that of Lut-R cells at 3 h. This study provides a new idea for improving the application of lutein in foods.