Google the words “human stem cells skin care” and you will see more than 3 million search results. But when it comes to topical skincare products, the discussion of stem cells is really about growth factors, cytokines and chemokines. Some are grown in the laboratory and others are found in stem-cell-conditioned media.
Cytokines and chemokines are signaling proteins, released by cells, that serve as messengers and affect the behavior of other cells. Cytokines, in particular, often regulate inflammatory responses. Growth factors stimulate cellular proliferation.
“Incorporating live cells into topical skincare products is not realistic,” says Sarah Bacus, PhD, a well-known scientist in the fields of cell biology and oncology, and co-founder and chief scientific officer at CeLuvia, a growth factor-based skincare line. “Stem cells and cells in general are notoriously difficult to keep alive in a laboratory, let alone in a skincare formulation. There is also no practical reason to include stem cells in a cream or apply them topically. There would be no benefit from this approach.”
Instead, formulators are working with byproducts of cultured cells—the above-mentioned cytokines, chemokines and growth factors—to spur skin cells into action, says Burt Ensley, PhD, CEO and chairman of Protein Genomics, a wound healing and tissue regeneration company, and DermaLastyl, an antiaging skincare company. “Skincare topicals are currently using the byproducts of culturing cells from various sources into a conditioned medium. Depending on the type of cells used and the processing methods, the output can be growth factors, matrix proteins and cytokines,” he says. “Human stem cell byproducts (from skin or adipose tissue) appear to be the best candidates for use in skincare products due to their ability to produce (in the right conditions) the same types of cellular components that your body naturally uses to maintain a youthful appearance.”
The type of stem cells used to create these byproducts, and how they are processed and formulated are the main points of differentiation in the over-the-counter products currently available.
Ronald Moy, MD, a Beverly Hills dermatologist and founder of the DNA EGF Renewal Collection, uses barley-bioengineered human-like epidermal growth factor (EGF) along with a trio of DNA repair enzymes. “The only products that make sense are those using human bioengineered growth factors that decrease with aging and have been studied in wound healing to be effective,” he says. “The soup of growth factors taken from neonatal foreskin or skin stem cells does not make scientific sense since they are not active by the time they are processed into a cream.”
Growth factors rarely stand alone in skincare formulations. Instead, products feature a blend of growth factors, cytokines, antioxidants and other antiaging ingredients. “Cellular rejuvenation is a complex process in which many signals working symbiotically are required. No one single ingredient/molecule is responsible for this process,” says Ensley, who also works with the U Autologous line, sold by Personal Cell Sciences, which uses stem cells extracted from the patient’s own adipose tissue to create individualized skin preparations consisting of Autokine (autologous stem-cell-conditioned media) with added peptides and antioxidants. “There are, however, notable cytokines involved in the process, including transforming growth factor beta-1, epidermal growth factor and basic fibroblast growth factor. Stem-cell-conditioned mediums are able to capture a varied set of these cytokines and deliver the complete set of instructions necessary for rejuvenation.”
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