Nonanimal Euglena gracilis-Derived Extracellular Vesicles Enhance Skin-Regenerative Wound Healing

This study proposes using microalgae-containing carbohydrate bioactives, an Euglena gracilis-derived extracellular microvesicle (EMV_EG) system, for enhanced skin regeneration. The critical deformation ratio, 1.67, during cell extrusion enables the authors to tune the particle size of the EMV_EG at ≈1 µm, thus satisfying the encapsulation yield of β-1,3-glucan and the cellular delivery performance. In vitro 5-bromo-2'-deoxyuridine and cell scratch assays reveal that the EMV_EG promotes the proliferation and migration of skin cells, thereby increasing both collagen synthesis and the expressions of proliferation-associated proteins. An ex vivo wound-healing test using both artificial and porcine skin reveals that similar to that seen using β-1,3-glucan, the EMV_EG can substantially increase the cell population, expressing the proliferation-related protein, termed proliferating cell nuclear antigen. These results demonstrate that the EMV_EG system shows considerable potential in the field of skin regeneration. This technique is expected to design new types of extracellular vesicles that are applicable for skin regeneration in the pharmaceutical and cosmetic industries.