Chitosan Nanoparticles, a Novel Drug Delivery System to Transfer Squalene for Hepatocyte Stress Protection

The Mediterranean diet is a well-known dietary pattern that has gained considerable popularity worldwide for its ability to prevent the progression of nonalcoholic fatty liver disease. This is largely attributed to the use of virgin olive oil as the primary source of fat, which contains a substantial amount of squalene, a natural antioxidant. In order to enhance the delivery of squalene and amplify its effects due to its highly hydrophobic nature, herein, squalene has been incorporated into chitosan nanoparticles. The characterization of the resulting nanoparticles was conducted via scanning electron microscopy, dynamic light scattering, ζ potential, Fourier transform infrared spectroscopy, and gas chromatography-mass spectrometry. Reactive oxygen species (ROS) generation and cell viability assays were conducted in oxidative and endoplasmic reticulum (ER) stress in AML12 and a TXNDC5-deficient AML12 cell line, which was generated by CRISPR/Cas9 technology. The results demonstrated that squalene was successfully encapsulated in chitosan nanoparticles and exhibited rapid and efficient cellular uptake at a 150 μM squalene concentration within 48 h. In conclusion, the encapsulation of squalene in chitosan nanoparticles, compared to the poly(d,l-lactide-co-glycolic acid) and ethanol drug carriers, significantly enhanced its cellular uptake. This allows the administration of higher doses, which improve hepatocyte viability and reduce ROS levels, effectively compensating for the adverse effects of TXNDC5 deficiency under the context of hepatocyte stress protection.