Tumor-responsive hyalo-chitosan nanoparticles for targeted delivery of andrographolide in CD44+ breast cancer cells.

Andrographolide (AG) has been reported for its anticancer activity. However, it is classified as a class IV in the biopharmaceutics classification system (BCS). Therefore, AG possesses low bioavailability due to its low solubility and permeability. In this study, hyaluronic acid-coated chitosan nanoparticles (Hyalo-CS-NPs) were formulated to enhance AG delivery and allow the active targeting of CD44 receptors overexpressed on breast cancer cells. Results showed optimized AG-Hyalo-CS-NPs with a size of 388.2 ± 1.41 nm, a zeta potential of -25.7 ± 1.58 mV, and an entrapment efficiency of 95.3%±1.01%. In vitro release profile revealed a sustained pH-responsive release from coated and uncoated CS-NPs with greater AG release under acidic conditions that mimic the tumor microenvironment. The MTT assay demonstrated the sharpest decline in the MCF-7 cell viability. Moreover, flow cytometry studies illustrated a significant apoptosis compared to uncoated nanoparticles and AG suspension. In addition, biochemical marker evaluation showed upregulating of the pro-apoptotic protein Bax and downregulating of Bcl-2, HER2, and Cyclin D1, confirming the underlying mechanism of the anticancer activity. Finally, confocal imaging showed higher intracellular uptake from coated and uncoated CS-NPs by 2.2-fold and 1.85-fold, respectively. In conclusion, AG-Hyalo-CS-NPs is a smart, targeted nanoplatform that improves AG anticancer efficacy in breast cancer management.