By now, BFT readers are well familiar with our disdain for the hyperbolic and confusing marketing messages constantly foisted upon skincare product consumers. For more than a decade, marketing maestros (charlatans?) tried to hoodwink scientifically unsophisticated women by commandeering the words “stem cell” to sell products having nothing to do with stem cells, or by ginning up the argument that a plant “stem cell” can somehow produce the biologic messenger molecules that will “instruct” human skin cells to change their errant ways. Hopefully, our readers have progressed beyond such semantic innocence and vulnerability. Today we want to go beyond scientific absurdities and address the real world differences between products that actually do contain human cell-derived growth factors and cytokines. The good news is there is abundant scientific documentation that confirms that topically applied human growth factors and cytokines can provide significant benefit to aging skin. Now, with the enhanced penetration and direct access to metabolically active skin cells produced through microneedling, the nature of applied bio-signals becomes even more important, and more potent in producing benefit…or harm. Thankfully, sorting this out is relatively simple since the scientific literature contains abundant instructive data and there is a growing body of supportive clinical evidence.
A Quarter Century of Research and Use The evidence proving benefit of growth factors and cytokines in wound healing dates back to the late 1980’s. A 1987 study examined the role of platelet-derived growth factor in wound healing. In vitro (laboratory benchtop) experiments showed PDGF (platelet derived growth factor) “stimulates DNA synthesis and chemotaxis of fibroblasts and smooth muscle cells and stimulates collagen, glycosaminoglycan, and collagenase production by fibroblasts. These in vitro properties suggest that PDGF, delivered by platelets to the site of injury in vivo, may play an important role in the initiation of the wound repair process.” The study further explained that IGF-1 (insulin-like growth factor 1) and EGF (epidermal growth factor, when combined with PDGF, provided additional synergistic benefit.
This diagram illustrates the negative influences on healing of lack of blood supply, oxygen, growth factors and cytokines on top, and the positive benefits of various important growth factors and cytokines on the bottom. The influences of growth factors and cytokines, however, is actually much more complex as there are dozens in play at any time, all competing for influence. The “net” effect of the overall bio-signal pattern is of paramount importance as is discussed below.
Drgeorge’s first exposure to clinical use of growth factors and cytokines was in the operating room in the early 1990’s when PDGF saturated gauze was packed into chronic non-healing ulcers in diabetic patients with good results. Since that time, platelet derived growth factors and cytokines have found clinical usefulness in bone and joint treatments, and as pro-healing adjuvants to promote tendon and ligament repair. It is thus no surprise that more than a dozen years ago, researchers became interested in documenting the benefits topically applied bio-signals provide to aging and photo-damaged skin. As explained below, the use of platelets to obtain bio-signals for topical application to the skin has pros and cons.
Early Evidence of Benefit
In the early 2000s, researchers began to explore the potential benefit of topically applied growth factors and cytokines to aging and photo-damaged skin. Some of the initial studies focused on bio-signals produced from cultures of fibroblasts, a reasonable cell type to consider because of its importance in production of collagen, elastin and intracellular matrix within the dermis. While evidence now shows that fibroblasts are not the optimal cell type from which to obtain such bio-signals, this early research set the stage for successful marketing of an entirely new class of topical skincare product.
Reversal of photodamage with topical growth factors: a pilot study. “The application of a mixture of topical growth factors may stimulate the repair of facial photodamage resulting in new collagen formation, epidermal thickening and the clinical appearance of smoother skin with less visible wrinkling.” J Cosmet Laser Ther. 2003 Apr;5(1):25-34.
Efficacy of novel skin cream containing mixture of human growth factors and cytokines for skin rejuvenation. “…significantly reduced periorbital and perioral wrinkles, as well as improved skin texture of the chin after one month of treatment, which confirms the beneficial use of growth factors and cytokines for skin rejuvenation reported in 2 earlier studies.” J Drugs Dermatol. 2007 Feb;6(2):197-201.
Endogenous growth factors as cosmeceuticals. “Topical application of human growth factors in multiple clinical studies has been shown to reduce the signs and symptoms of skin aging, including statically significant reduction in fine lines and wrinkles and increase in dermal collagen synthesis.” Dermatol Ther. 2007 Sep-Oct;20(5):350-9.
Human growth factor and cytokine skin cream for facial skin rejuvenation as assessed by 3D in vivo optical skin imaging. “Growth factors, in addition to their crucial role in cutaneous wound healing, are also beneficial for skin rejuvenation. Due to their multifunctional activities such as promoting skin cell proliferation and stimulating collagen formation, growth factors may participate in skin rejuvenation at various levels. […] We found that topical application of growth factors and cytokines are beneficial in reducing signs of skin aging.” J Drugs Dermatol. 2007 Oct;6(10):1018-23.
Reduction in facial photodamage by a topical growth factor product. “This study demonstrates that addition of a topical formulation of growth factors and cytokines to a basic skin care regimen reduces the signs of photoaging.” J Drugs Dermatol. 2008 Sep;7(9):864-71.
Topically applied physiologically balanced growth factors: a new paradigm of skin rejuvenation. “Clinical studies have shown that topical application of products containing high concentrations of a physiologically balanced mixture of GF appears to reverse the signs of skin aging.” J Drugs Dermatol. 2009 May;8(5 Suppl Skin Rejuenation):4-13.
Healing is like a Symphony Orchestra, not a String Quartet The body contains trillions of cells, divided into over 200 different individual types of cells. Of these, only the red blood cell does not participate in the complex communication system that controls cellular behavior, including growth, regeneration, inflammation, and healing of tissue.
The “words” of communication are growth factors and cytokines (among others). They function by activating cellular membrane receptors that in turn initiate cascades of intracellular biochemical interactions that reach all the way to the nucleus, up-regulating and down-regulating genetic behavior – powerful signals, indeed. Below is a simple schematic of a cell receptor being activated; below that an example of the consequential complex intracellular events of that activation that determine whether a cell divides, differentiates, migrates, or performs any one of a myriad of other possible actions. Growth factors and cytokines make tissue healing, and indeed life itself, possible.
Growth Factors and Cytokines Never Exist in Isolation
There are dozens and dozens of bio-signals in the orchestra of healing; they never exist as single substances. Because of the complexity of cellular communications, they may have resultant complementary or opposing effects. It is always the net “pattern” present that determines the physiologic effect. When cells are cultured in the laboratory to harvest growth factors and cytokines as an ingredient for an anti-aging skincare product, or an adjuvant useful for microneedling, the sources of the bio-signals, and particularly the type of cell cultured, is of paramount importance. It determines the type and character of bio-signals produced and their relative concentration. As demonstrated below, these are both important considerations when selecting the optimal source from which bio-signals for anti-aging and microneedling should be obtained. As a starting point, we need a brief word on inflammation and healing, particularly in the skin.
Inflammation – Not a Good Thing when it comes to Skin Healing
By now, nearly everyone is aware that inflammation is the enemy of good health when it is of the chronic smoldering variety. Inflammation is associated with nearly every disease, malady, or debilitating condition of the elderly. It is also associated with aging of skin and all that comes with it including abnormal pigmentation, redness, wrinkles, fine lines, etc. In darker skin types, inflammation of any sort is notorious in producing abnormal pigment patterns. Aesthetic treatments that cause deliberate tissue damage in order to promote new younger looking skin may have undesirable results (fibrotic healing or abnormal pigmentation) with inflammation as the primary culprit.
inflammation should be considered a good thing except in those cases where mother nature is concerned with destroying pathogens or mopping up damaged or dead tissue – like in the very old days when a cave man was bit by an animal or cut his leg on a rock. Modern hygiene and sterile medical procedures make the inevitable inflammation seen after trauma somewhat unnecessary and potentially counterproductive to producing the most pleasant aesthetic result. For that reason, BFT considers products that are pro-inflammatory, especially when intended for chronic use, less than desirable.
In choosing a product for topical skincare or microneedling that contains human derived growth factors and cytokines, there are three principal considerations as to what is the best cellular source for the bio-signals – what is the pattern, and what are the concentrations, of the bio-signals produced by that cell in culture, and how are the growth factors and cytokines being processed. While assays provide precise answers to these questions (and examples will be provided below), good insight can be gleaned by examining the physiologic role each type of cell plays in the body, and the ways in which products are produced from the cells after culture. Brand names are not important for this exercise. BFT will let that be the readers’ homework assignment.
This chart lists the growth factors and cytokines primarily involved in healing and regeneration of tissues. Of particular note is that nearly all can be categorized according to their impact on inflammation, either acutely or chronically pro-inflammatory, or anti-inflammatory. These distinctions are important when one determines if a growth factor and cytokine “cocktail” in a product is likely to promote inflammation or quench it.
Cytokine Patterns Produced by Cell Cultures differ Dramatically
It is not surprising that cell culture growth factor and cytokine outputs vary dramatically because the cells cultured perform completely different physiologic roles. It is also not surprising to learn that stem cells, in particular, are prolific producers of cytokines and growth factors since that is an important function they serve in tissue, influencing the behavior of other cells. Adipose (fat) derived and bone marrow derived mesenchymal stem cells are cultured but produce dramatically different growth factor and cytokine patterns, consistent with the fact they perform markedly different functions in life.
It is now well recognized that fat is a pro-inflammatory “endocrine organ”, associated with increased incidence of many diseases that increase in incidence with age, most notably cardiovascular disease, diabetes, cancer and others. Bone marrow mesenchymal stem cells, on the other hand, are now recognized as the body’s commander-in-chief of healing in all tissues. Although these cells originate in the bone marrow, like red and white blood cells and platelets, they enter the vascular system enabling them to “patrol” all tissues.
When injury is encountered, bone marrow stem cells can differentiate into specific types of repair cells (e.g. bone, muscle, cartilage, skin, etc.) but that appears to be a secondary role. Their more important function is to orchestrate the healing process by acting as smart mini-drugstores, essentially instructing other cells how and when to participate in tissue repair. A chief function is modulating and dampening the inflammation associated with injury and the early healing phases. The growth factor and cytokine patterns of adipose and bone marrow mesenchymal stem cells in culture are below and consistent with their very disparate physiologic functions. The “teeter-totter” schematic is useful in demonstrating the comparative difference in the pro-inflammatory and anti-inflammatory nature of the growth factors and cytokines produced by adipose and bone marrow stem cells. As discussed above, if the effort is to provide anti-aging benefit, particularly in a product intended for daily use, an anti-inflammatory bio-signal pattern is clearly preferable. Which brings us to PRP (platelet rich plasma), now popular for use with microneedling.
As mentioned above, PRP presents a conundrum of sorts. While true that platelets contain beneficial growth factors and cytokines, they also are sources of some of the most powerful pro-inflammatory cytokines, specifically TNF-α, Il-1, and Il-6. Furthermore, medical microneedling (at depths capable of producing injury to dermal capillaries) results in varying degrees of tissue bleeding that will itself result in platelet cytokine activation. Recall that the first phase of healing, whether a wound is sterile or contaminated, involves inflammation from platelet activation. The question: Is there value in promoting more robust inflammation through the use of topical PRP during microneedling? BFT is not convinced that is a good idea.
Nor is Dr. Lance Setterfield, the author of The Concise Guide to Dermal Needling, whose opinion is that inflammation should be minimized, not promoted. His hypothesis is that the injury of keratinocytes within the upper layers of the skin is sufficient to stimulate release of pro-healing stimulatory growth factors and cytokines and that deliberate use of pro-inflammatory topical adjuvants may be ill advised and potentially detrimental.
For an in depth discussion of the science supporting the microneedling, BFT highly recommends his book which can be purchased through amazon.com or his website, www.acaciadermacare.com.
Fibroblasts, the First Cells Cultured to Obtain Growth Factors and Cytokines for Skincare is a Questionable Choice
Fibroblasts are poor producers of bio-signals. In a study that compared the production of important growth factors and cytokines by fibroblasts to that of bone marrow mesenchymal stem cells determined that the latter produces 15 to 50 times more bio-signals. The same study showed that bone marrow stem cells use bio-signals to promote fibroblasts to “proliferate, migrate and increase expression of genes important in wound repair.” It is clear from this study that fibroblast are the corporals taking orders their orders from bone marrow stem cells. (Mesenchymal stem cells induce dermal fibroblast responses to injury; Experimental Cell Research Volume 316, Issue 1, 1 January 2010, Pages 48–54 This is yet another article pointing to the important role bone marrow mesenchymal stem cells play in skin healing. A number of earlier articles gave similar insight.
- “A significant number of bone marrow cells traffic through both wounded and non-wounded skin.” J Cell Physiol. 2003 Aug;196(2):245-50
- “The bone marrow contribution to normal skin and healing of cutaneous wound is substantially greater than the previously recognized.” Stem Cells. 2004;22(5):812-
- “BM-MSC-treated wounds showed rapid closure and increased collagen synthesis, cellular proliferation and angiogenesis, and decreased expression of pro-inflammatory cytokines.” Tissue Eng. 2007 Jun;13(6)
- “Bone marrow-derived cultured stem cells delivered in a fibrin spray accelerate healing in murine and human cutaneous wounds.” Tissue Eng. 2007 Jun; 13(6)
- “Bone marrow stem cells participate in tissue repair through remodeling and regeneration of damaged areas.” Stem Cell. 2008 Spring
An important article, supportive of the use of bone marrow stem cell conditioned media in anti-aging skincare products and microneedling, concluded: “…evidence shows that administration of BMSC-derived conditioned media can produce the same beneficial effects that are observed after stem cell therapy.” In other words, the nutrient broth from cell culture, after the cells had been filtered out completely, had the same efficacy as the cells themselves. Bone Marrow Research, Vol. 2011, Article ID 207326
Which brings us to an interesting way in which to deliver cell culture-derived growth factors and cytokines to skin – and one BFT does not consider scientifically valid – slather on some hamburger! What, you say, can that possibly mean? Consider this: if one were to grow a large number of cells in culture, then discard, not keep the conditioned media in which they were grown, then freeze and thaw all the cells until they ruptured (scientifically termed “lysed”), you would have replicated the technique used by some companies to create topical skincare products. So instead of applying growth factors and cytokines, you’d be applying all the parts of the cell (membrane, cytoplasm, organelles, RNA, DNA), exactly what is in hamburger – all the cell and cell parts.
BFT sees two major problems with this as a concept in general, and one when considered as a strategy for use in microneedling.
1) The cell remnants applied to the skin, on a molecular basis, would be huge, unable to penetrate the stratum corneum to any meaningful degree.
2) As discussed many times on the blogsite, cells communicate using specific molecular bio-signals called growth factors and cytokines (and others.) Cell secrete these molecules into the fluid in which they live, which then diffuse to nearby cells, activating cellular membrane receptors and thereby influencing the behavior of the nearby target cells. This type of signaling, called paracrine signaling, is not likely to happen if the bio-signals secreted into the nutrient broth during culture are flushed down the drain and only the cellular “puree” is applied to the skin. Nature does not work that way.
3) When used with microneedling, such large molecular substances will have ready access to deeper layers of the skin since its barrier function has been temporarily breached by the thousands of tiny needle perforation. Such a scenario could possibly lead to genetically foreign material gaining access to the skin, leading to potential immunologic attack. Such attack is inflammatory in nature, not a good thing to promote improved aesthetics.
Fibroblasts from fetal skin and parthenogenic embryonic stem cells (unfertilized human ova chemically induced to proliferate), are used to make lysed cellular ingredients for skincare. On intact skin, BFT is of the opinion that improvements may be as much related to the “spackle” effect (like patching plaster cracks in a wall) as opposed to cellular responses to growth factors and cytokines. We are willing to learn, however, if someone affiliated with the companies making these products would care to discuss the science further.
What Should you Do?
A general consensus is beginning to develop among experts in the microneedling field and that is material foreign to normal human skin should not be applied during or for the first few hours after microneedling. In this way, the potential of foreign substances, a.k.a. “troublemakers”, entering into the skin will not exist, hence they will not be able to initiate adverse reactions. (Keep watching BFT, as we are now receiving more and more examples of adverse reactions from microneedling misadventures where substances foreign to human skin gained access, producing nasty allergic and inflammatory conditions, some quite severe and likely to lead to permanent disfigurement.)
What the BFT docs did.
We’re not secretive about our day jobs – we are physician/scientists who work with bone marrow mesenchymal stem cells. Our approach to microneedling was to create a topical product that contains only substances normally found in the skin: hyaluronic acid, growth factors and cytokines from laboratory culture of bone marrow stem cells, and for some product, additional TGF-beta 3, the superhero molecule of anti-inflammation. Many thousands of treatments over the past several months, very impressive results, and not a bad reaction among the lot.