Stem Cell-Derived Nanovesicles: A Novel Cell-Free Therapy for Wound Healing

Figure 2

Schematic diagram of CDN biogenesis, structural composition, and cellular internalization. Exos are formed following plasma membrane invagination to form MVBs that are then exocytosed. The main components of CDNs are lipids, proteins, and nucleic acids. CDN lipids include cholesterol, ceramides, and phosphatidylserines, while CDN proteins include ubiquitous tetraspanins (CD9, CD63, and CD81) and HSPs. CDNs can (i) trigger cell signal transduction through intracellular signaling pathways and release of secretory contents; (ii) fuse with cell membranes, transfer proteins and genetic content, and enter the cytoplasm of recipient cells; and (iii) be endocytosed through phagocytosis, macropinocytosis, or receptor-mediated endocytosis.