What's the Deal with Exosomes?
Exosomes are extracellular particles that are “manufactured” and released from cells to the blood to transmit information to a nearby cells or organs. These small or nano-particles contain lipids, proteins and nucleic acids including bits and pieces of DNA as well as segments of messenger RNA called microRNA (miRNA). We now know that the cells in our body are able to communicate constantly with others through the information contained in these exosomes.
Exosomes are obtained from fluid media of cell cultures mainly of human-derived fat cells (adipocytes), placenta tissue, bone marrow, or the umbilical cord. Cells obtained from these organs contain a high number of mesenchymal stem cells or MSC that have been widely used in clinical trials because of their potential in the treatment of various metabolic defects and diseases. Exosomes have wide applications in therapeutic treatments such as the treatment and detection of cancer and other genetic diseases. They are also used to deliver medications to targeted tissues. Exosomes contain high concentrations of various growth factors including vascular endothelial growth factors (VGEF), transforming growth factor (TGF-β1), FGF (fibroblast growth factor) , EGF (epidermal growth factor) etc. Many of these growth factors participate in biological activities such as cellular growth, cellular repair, and collagen stimulation. Exosomes are called nanoparticles as they are very minute in size, even below the size of some viruses. Exosomes are purified from processes such as ultra-filtration, ultra- centrifugation or other isolation techniques. These particles are stringently screened for various viral and bacterial contaminants. Yet, the exosomes isolated from the culture media have shown to retain a lot of biological activities at high purity.
Exosomes are playing an emerging role in the dermatological and aesthetic field, namely in the area of regenerative medicine. We know that much of skin ageing is determined by extrinsic factors such as UV exposure, air pollution, smoking, nutritional deficiencies etc. A proportionately smaller degree of ageing is from intrinsic factor such as cellular apoptosis or hormonal changes. With the ageing of skin, there is a higher propensity of trans-epidermal water loss (TEWL), thereby increase skin dryness and skin coarseness. There is also a decrease in extracellular matrix components including collagen and elastin fibers which result in skin laxity and the appearance of wrinkles. These signs of ageing can be reversed if we can correct some of these structural changes of the skin. Researchers have begun to look into exosomes. To combat skin ageing, various technologies have recently been developed to produce controlled injuries to the skin, which in turn enhance tissue repair and skin rejuvenation. Devices such as radio frequency or lasers cause controlled tissue injury, which is followed by collagen remodeling and the synthesis of elastin and dermal collagen in the treatment area. To further enhance the repair process, exosomes can be applied topically after such skin procedures. Researchers have discovered that not only does the skin heal up faster with exosomes, the visible degree of skin rejuvenation is also greatly increased. Exosomes can also be delivered by injections but this method of delivery is still under investigation.
Exosomes treatment is suitable for both younger and more mature skin. For the younger population in their 20’s to 40’s, the treatment can target large pores, melasma, acne, rosacea, and acne scars. For the more mature population in their 40’s to 60’s, it targets the fine lines and wrinkles, crepey dry skin, mild laxity, as well as uneven skin tone.
In recent years, exosomes have been explored in the treatment of other skin ailments. Growth factors and micro RNA contained inside the exosomes engage in the regulation of various cellular activities. It also has angiogenic or new blood vessel forming potentials because of the presence of VGEF and miRNA contained in the exosomes. New collagen synthesis and laying down of new elastin and ECM (extracellular matrix) are stimulated by the presence of growth factors such as TGF -β1 and FGF. Enzymes and proteins such as MMPs (matrix metalloproteinases) and TNF-α that control ECM degradation and apotosis (programmed cell death) are downregulated and suppressed. Exosomes have also been investigated in the treatment of atopic dermatitis. MiRNA in the exosomes can suppress the expression of inflammatory cytokines which have been implied in the pathogenesis of this skin disease. Exosomes have also been used successfully in selected cases of wound healing and skin ulcers.