Sonochemical synthesis of protein microcapsules loaded with traditional Chinese herb extracts

Abstract

Traditional Chinese herbs have attracted extensive attention due to their good efficacy, low toxicity, and minor side effects. However, some active ingredient extracts are relatively sensitive to external influence and liable to lose their effectiveness. Different from the traditional and complex encapsulation methods, one can easily prepare drug-loaded microcapsules to improve their bioavailability using the new encapsulation technology. In this work, we used the sonochemical method to prepare bovine serum albumin (BSA)/astragalus membranaceus oil (AM) microcapsules. The technology was simpler, greener, and more efficient. Thereinto, BSA and AM oil were used as the shell material and the core material, respectively. The effects of ultrasonic amplitude, ultrasonic mode, and ultrasonic time on synthetic reactions were studied. The morphology and size of the BSA/AM microcapsules were investigated using transmission electron microscopy, scanning electron microscopy, and dynamic light scattering (DLS). The loading efficiency and drug release behavior were determined using thermogravimetric analysis (TGA) and ultraviolet (UV) spectroscopy, respectively. The best ultrasonic synthesis conditions were obtained by the above analysis, with an ultrasound amplitude of 30%, ultrasound mode of the pulse mode of 2 s, ultrasound time of 4 min. The DLS results show that the microcapsule size is 484.4 nm and the polydispersity index is small. The TGA results show that the drug loading efficiency is about 77%, and the hemolysis tests show that the BSA/AM microcapsules have no cytotoxicity at lower concentrations (lower than 50 μg·mL−1).

Keywords

• sonochemistry
• chinese herb microcapsules
• bovine serum albumin
• astragalus membranaceus oil