Introduction: Nanoscale drug delivery systems represent a promising approach for improving efficiency and safety of chemotherapy. However, many synthetic nanocarriers may cause toxicity and immune reactions, which limit their biomedical application. In this study, we developed hybrid nanoparticles based on extracellular vesicles and cell membranes. Such nanoparticles may combine the high biocompatibility of vesicles with membrane-derived biological functions and the ability to cross biological barriers.

Methods: Human embryonic kidney HEK293 cells were used as a source of extracellular vesicles and cell membranes. Hybrid nanoparticles were prepared by extrusion through polycarbonate membranes. To optimize particle size distribution, we tested different numbers of extrusion cycles (5, 10, 15, 20, and 25). Doxorubicin (DOX) loading was performed using two methods: a pH gradient and an ammonium sulfate gradient. The pH gradient method provides DOX diffusion through the membrane, followed by protonation and retention inside the particles, while the ammonium sulfate method relies on ionic gradients and the formation of poorly soluble sulfate complexes.

Results: The results demonstrated that 15 extrusion cycles were optimal for obtaining hybrid particles with the monodisperse size distribution. DOX loading using the pH gradient method produced particles with an average diameter of 250 ± 190 nm and a DOX concentration of 12 ± 1 µg/mL. In contrast, the ammonium sulfate gradient method resulted in a significant increase in particle size to 780 ± 360 nm, while the DOX concentration was 10 ± 3 µg/mL.

Conclusions: Overall, the pH gradient method was more suitable for the preparation of DOX-loaded hybrid nanoparticles with improved tumor accumulation. The developed hybrid system represents a biocompatible platform for further in vitro studies as a drug delivery approach for cancer therapy.

This work was supported by the Russian Science Foundation research grant No. 25-75-00151, https://rscf.ru/project/25-75-00151/