Comparative Analysis of Methods for the Formation and Cytostatic Activity of the Vesicular Form of Doxorubicin

The clinical efficacy of systemic therapies for oncological diseases is limited by their toxic effects on healthy tissues and the risk of fatal complications developing. One way to address this problem is to develop technologies for the targeted delivery of anticancer drugs. Autologous extracellular nanovesicles (ENVs) can serve as a basis for innovative systems for the targeted delivery of cytostatics. There are several methods for “loading” ENVs with cytostatics, but practical selection of the optimal approach is hampered by the lack of universal evaluation criteria and systematic comparative studies. Therefore, the aim of this work is to compare technologies for loading an anticancer drug (doxorubicin) into plasma ENVs. The ENVs are isolated from the plasma of healthy donors and analyzed using nanoparticle tracking analysis (NTA) and flow cytometry. Electroporation and sonoporation technologies in various modifications are used to load doxorubicin into the vesicles. The effect of the treatment is assessed using NTA, the efficiency of loading is assessed using absorption spectroscopy, and the cytostatic effect of the vesicular form of the drug is assessed using the MTT assay on MCF-7 and BT474 breast cancer cells. Based on analysis of ENV integrity, the optimal conditions for electroporation and sonoporation are determined. Sonoporation in the mode of 35 kHz, 40 W, 4 cycles (30–120 s) shows an advantage, with a loading efficiency of 32.2%. The cytostatic activity of the vesicular form of doxorubicin is higher compared to the drug solution under in vitro experimental conditions. Sonoporation is an effective method for loading doxorubicin into ENVs, based on which a vesicular delivery system for anticancer drugs can be developed.