Polymer-engineered delivery systems for Schisandra lignans: A review of advances in hepatic-targeted therapy

The Schisandra plant (Magnoliaceae) is an important tonic herb in traditional Chinese medicine and has a long history of medicinal use in China, Japan, Korea, and other countries. In recent years, with the increasing global burden of liver diseases, the potential of Schisandra and its main bioactive component, lignans, in the prevention and treatment of liver diseases has attracted much attention. This review systematically summarizes the sources, classification, and extraction and purification methods of Schisandra lignans. Particularly noteworthy is the detailed review of the progress in formulation development: from traditional Chinese medicine prescriptions to advanced drug delivery systems based on macromolecular polymers (such as polymer-functionalized nanoparticles, polymer-modified/stabilized liposomes, polymer micelles, polymer-stabilized microemulsions, and polymer microspheres). The article further discusses the analytical methods and in vivo pharmacokinetic characteristics of polymer-complexed lignans, revealing the optimizing effect of polymer carriers on their in vivo behavior. Furthermore, this review provides an in-depth discussion of the pharmacological mechanisms of Schisandra lignans in the treatment of liver-related diseases, and analyzes the theoretical basis and application prospects of polymer-mediated targeting strategies-such as active/passive hepatic targeting and tumor microenvironment-responsive delivery-in enhancing their therapeutic efficacy. Collectively, this study establishes a comprehensive theoretical framework to support the development of efficient, low-toxicity, innovative formulations of Schisandra lignans based on macromolecular polymer technology, facilitating their clinical translation.