Since few transplanted cells persist in vivo, the beneficial effects of cell therapy may lie in the secreted factors being the active component of this treatment.
A key part of paracrine secretion is Exosomes, which are membrane vesicles that are stored intracellularly in endosomal compartments and are secreted when these structures fuse with the cell plasma membrane.
- Exosomes contain protein, DNA, and RNA, thus making them an attractive vector of paracrine signals delivered by stem cells.
- Exosomes may also be “loaded” with predetermined proteins and nucleic acid to achieve a desired effect (1).
- Exosomes can be stored as an “off-the-shelf” product having the potential for circumventing many of the limitations of\viable cells for therapeutic applications in regenerative medicine.
- In vitro, exosomes from pre-adipocytes stimulate cell proliferation in a wound healing model.
- In vivo, adipose-graft derived exosomes have been shown to be a promising tool for skin repair and remodeling (2).