Ultrasonic Self-Emulsification Nanocarriers for Cellular Enhanced Astaxanthin Delivery

Oil in water (O/W) nanocarriers were prepared for cellular enhanced astaxanthin delivery using a (3-carboxypropyl) triphenylphosphonium bromide (TPP)-modified casein by an ultrasonic self-emulsification method. The nanocarriers of casein emulsion loaded with astaxanthin and casein modified by TPP emulsion encapsulated with astaxanthin were 227 and 543 nm, respectively, with a spherical shape. The thermal stability and resistance to ultraviolet (UV) radiation ability of astaxanthin were significantly improved after encapsulation by the nanocarriers. The fluorescence colocalization imaging proved an accumulated effect of astaxanthin encapsulated in casein emulsion nanocarriers modified by TPP. Meanwhile, the astaxanthin loaded on TPP-modified nanocarriers could significantly protect the mitochondrial membrane potential from depolarization in the normal rat kidney (NRK) cells after oxidative damage. The cell viability assay demonstrated that the astaxanthin loaded on TPP-modified nanocarriers could enhance the growth of NRK and RAW264.7 cells as compared with astaxanthin encapsulated by casein emulsion without TPP modification.