The cell membranes in our body are composed of lipid bilayers that strictly limit the penetration of water-soluble molecules, other than lipid-soluble substances. High-molecular-weight functional proteins and nutritional proteins are water-soluble, which are limited in penetrating body membranes (cell membranes and tissue barriers) into important sites. To overcome the low penetration rate, exosomes, i.e., extracellular vesicles (EVs), are tools for transfer of the functional molecules such as intercellular signaling and growth factors by wrapping them in nano-sized (50~100 nm) lipid membranes. Exosomes released from functional cells efficiently deliver >2,000 effector (functional) molecules to target cells and injured/inflamed sites, and thereby regulate body functions, protect/regenerate cells, and restore tissues. Therefore, exosomes are very effective in overcoming diseases and aging as well as preserving health at early- to mid-term diseases and aging.

• Stem cells: 10-20 μm (micro-sized) – limited skin/tissue penetration
• Exosomes (containing functional molecules): 50-100 nm (nano-sized: 1/200 of stem cells) – readily penetrate skin/tissues (skin, blood-brain barrier, nasal mucosa, etc.)
• Functional molecules: mainly water-soluble – hardly penetrate skin/tissues

The content of exosomes is very low (<0.2%) in normal conditioned (culture) medium (CM), and they can be ruptured during extraction, which may hinder the transfer of water-soluble proteins. This is why high concentration and preservation of the exosomes are extremely important. Exosome-rich conditioned medium (ERCM) of Designed Cells obtained by hypoxia culture after treating with specific cytokines contains 50~100 times the intact exosomes in CM. ERCM is highly effective in AD, stroke, glaucoma, arthritis, atopy, skin regeneration and beauty, and so on.