Exosomes, a class of double-membraned vesicles with diameters of approximately 30–200 nm, are capable of carrying bioactive molecules to mediate intercellular communication and exhibit considerable potential in disease treatment and health-related fields. However, current research remains largely focused on animal-derived exosomes, leaving significant gaps in understanding the secretion mechanisms, functional properties, and scalable production of plant-derived exosomes, particularly those from microalgae. In this study, five high-value microalgal species ( Chlorella sorokiniana , Botryococcus braunii SAG 30.81, Isochrysis galbana , Scenedesmus quadricauda , and Spirulina sp.) were selected to systematically compare their growth characteristics and exosome yields. In addition, a multi-dimensional characterization system was used to assess particle size distribution, followed by transmission electron microscopy and functional protein expression. In the H 2 O 2 -induced oxidative damage model of HaCaT cells, microalgae exosomes demonstrated reparative potential and contributed to the regulation of the Nrf2/ARE signaling pathway. Results indicated that exosomes from Chlorella sorokiniana (CS-Exo) exhibited significantly higher yields than those from other species, with mixotrophic cultivation conditions further enhancing both yield and functional protein content. Cell-based assays confirmed that CS-Exo effectively reduced intracellular reactive oxygen species levels, and increased antioxidant enzyme activities. A zebrafish in vivo model also confirmed these antioxidative benefits. This study established an integrated research pathway spanning strain selection, exosome characterization, and functional verification. This work provides a theoretical foundation for the application of microalgal exosomes in biomedical areas such as skin repair, as well as a technical basis for the valorization of microalgae derived from aquatic environments.
Yang et al. (2026) studied this question.