Chrysin-loaded Soluplus-TPGS mixed micelles: Optimization, characterization and anticancer activity against hepatocellular carcinoma cell line

Abstract

Chrysin is a natural flavonoid found in various plants, and it has shown potential therapeutic benefits such as anti-inflammatory, antioxidant, and anticancer properties. However, its clinical application is limited due to poor solubility and low bioavailability. Mixed micelles can help overcome these problems. This study focuses on preparation of Chrysin-loaded mixed micelles with the help of solvent diffusion evaporation method. Soluplus and TPGS were the main components of the formulation, and their proportions were optimized with the help of the central composite design matrix. Thirteen batches were constructed to optimize the mixed micelle formulation based on different Soluplus: Chrysin ratios and TPGS percentages. Response surface methodology and various models were employed to analyze micellar size, size distribution, encapsulation efficiency, and drug loading. The optimized formulation, CHR-MM1, exhibited a particle size of 132.2 ± 7.9 nm, encapsulation efficiency of 98.01 ± 2.27 %, and a zeta potential of −2.10 mV. TEM images revealed that the micelles were spherical in shape. Characterization studies, including FTIR and X-ray diffraction, confirmed the successful encapsulation of Chrysin in an amorphous form within the mixed micelles. The in vitro release studies demonstrated a sustained release behavior in both acidic and neutral pH conditions. The Korsmeyer-Peppas model best described the drug release kinetics. Cellular uptake studies using fluorescence microscopy revealed enhanced internalization of the mixed micelles into Hep G2 cells. Moreover, MTT assays indicated a concentration- and time-dependent cytotoxicity of Chrysin-loaded mixed micelles against Hep G2 cells, outperforming free Chrysin. The flow cytometry analysis results suggested an enhanced apoptotic activity of Chrysin in the mixed micelles as compared to free drug. This study provides a promising strategy for improving the solubility, cellular uptake, and cytotoxicity of Chrysin. Therefore, our results point to the potential of Chrysin-loaded mixed micelles to serve as a therapeutic option for hepatocellular carcinoma.