ABSTRACT
This study aimed to prepare an anti-metastatic diallyl trisulfide-exosome (DATS-Exo) drug delivery system. Exosomes in the supernatants of lung metastasis mouse melanoma B16BL6 cell line culture were extracted by ultracentrifugation. The quantity of exosomes was determined by transmission electron microscopy (TEM), Malvern particle size meter, and BCA assay. Expression levels of exosome-specific biomarkers CD9, TSG101, Flotillin 1 and lung organotropic biomarker α6 were detected by Western blot. The sonication method was used to load DATS into exosomes. The uptake of exosomes by B16BL6 cells and lung tissue was observed by laser confocal microscopy. Wound healing assay was used to evaluate the anti-migration effect of DATS-Exo in vitro. Experimental lung metastasis model was established to evaluate the anti-metastasis effect of DATS-Exo in vivo. Animal experiments have been approved by the Ethics Committee of Nanjing University of Chinese Medicine. The results showed that the particle size of DATS-Exo was 112.3 ± 1.98 nm, polydispersity index (PDI) was 0.24 ± 0.08, zeta potential was -24.33 ± 4.11 mV, and the particles have classic tea tray-like membrane structure under TEM. The protein concentration of DATS-Exo was measured to be 1 312.33 ± 6.27 μg·mL-1. The drug loading rate was about 0.33% ± 0.02%. The exosomes could be taken up by B16BL6 cells and the lung tissue. Compared with the free DATS group, DATS-Exo had a better inhibitory effect on tumor metastasis in vitro and in vivo. Taken together, these results indicate that exosomes derived from the lung metastasis tumor cells have lung organotropic characteristic and drug-loading properties. Using these kind of exosomes as carrier for anti-tumor drug delivery can be a novel and effective strategy of anti-metastatic therapy.
ABSTRACT
Objective To prepare diallyl trisulfide microemulsion (DATS-MEs) and evaluate its effect on the proliferation and migration of tumor cells. Methods Using HS15 as emulsifier, PEG400 as co-emulsifier and DATS as the oil phase, water titration method was used to prepare DATS-MEs. The influence of DATS-MEs on the proliferation of mouse Lewis cancer LLC cells and mouse melanoma B16BL6 cells in vitro was evaluated by the tetramethyl azoline blue (MTT) methed; Wound healing assay was used to evaluate the effect of DATS-MEs on the migration of LLC and B16BL6 cells in vitro. Results The DATS-MEs obtained was stable, clear, transparent, and well dispersed. The particle size of DATS-MEs was (16.72 ± 0.22) nm, the polydispersity index was 0.03 ± 0.01 and the Zeta potential was (-4.98 ± 0.11) mV. The encapsulation efficiency (EE) of DATS in microemulsion was 82.89%, the drug loading (DL) was 6.28%. The solubility in water increased by about 2 367 fold compared with the free DATS. DATS-MEs and free DATS at concentration of 10, 30, and 50 μmol/L all can effectively inhibit the migration and proliferation of LLC cells and B16BL6 cells in a dose-dependent manner. DATS microemulsion was proved to be more effective than free DATS. Conclusion After assembly into DATS microemulsion, the stability and solubility in water of DATS was enhanced. The anti-proliferation and anti-migration on mouse Lewis LLC cells and mouse melanoma B16BL6 cells were significantly enhanced.