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

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.