Construction and Evaluation of Hepatic Targeted Drug Delivery System with Hydroxycamptothecin in Stem Cell-Derived Exosomes

Hydroxycamptothecin (HCPT) is commonly used in the treatment of liver cancer; however, its low water solubility and poor stability significantly limit its clinical application. In recent years, research on exosomes has deepened considerably. Exosomes possess a unique phospholipid bilayer structure, enabling them to traverse tissue barriers, which provides natural advantages as drug carriers. Nevertheless, delivering exosomes safely and efficiently to target cells remains a major challenge. In this study, we utilized the affinity of the SP94 peptide for human liver cancer cell receptors. HCPT was coated with exosomes in our experimental design, and the exosome membrane was modified with SP94 peptide to facilitate drug delivery to liver cancer cells. Exosomes were purified from bone marrow mesenchymal stem cells, and targeted peptides were attached to their surfaces via post-insertion techniques. Subsequently, HCPT was incorporated into the exosomes through electroporation. Using the HepG2 hepatoma cell line, we evaluated a series of in vitro pharmacodynamics and studied pharmacokinetics and tissue distribution in animal models. The results indicated that ligand-targeted, modified drug-carrying exosomes significantly enhance drug bioavailability, prolong retention time in vivo, and facilitate liver targeting. Moreover, this approach reduces drug nephrotoxicity, enhances anti-tumor efficacy, and lays the groundwork for the development of novel liver cancer-targeting agents.