Preparation and Characterization of Allicin-Loaded Solid Lipid Nanoparticles Surface-Functionalized with Folic Acid-Bonded Chitosan: In Vitro Anticancer and Antioxidant Activities.

Abstract

This investigation aimed to increase the bioavailability and anticancer effects of allicin (AC) by encapsulating it in solid lipid nanoparticles (SLN) decorated with chitosan (CS)-conjugated folic acid (FA). Nanoparticles (NPs) were synthesized by high-pressure homogenization, and then, Fourier-transform infrared (FTIR), Field-Emission Scanning Electron Microscopy (FESEM), Dynamic Light Scattering (DLS), and zeta potential methods were used to determine their physicochemical characteristics. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to assess the effect of toxicity and flow cytometry, while fluorescent staining methods were used to investigate the type of cell death. Real-time quantitative polymerase chain reaction (qPCR) was used to evaluate the expression levels of apoptotic genes: Bcl-2, and caspase-8. The presence of AC-SLN-CS-FA with a spherical morphology, an average size of 86.7 ± 9.4 nm, uniform distribution (0.31), a surface charge of +21.3 ± 13.3 mV, an encapsulation percentage of 86.3%, and a folate binding rate of 63% confirmed the success of the preparation method. Suppression of MCF-7 cancer cells and non-toxicity of AC-SLN-CS-FA on Human foreskin fibroblast (HFF) normal cells were confirmed by cytotoxic assay. The results of flow cytometry revealed that the cells were arrested in the sub-G1 phase, and the activation of the intrinsic apoptosis pathway was confirmed by the results of real-time qPCR. In general, AC-SLN-CS-FA has the potential to prevent free radicals and trigger apoptosis in cancer cells by activating the intrinsic apoptosis pathway; thus, making it a promising subject in preclinical research.