Is it true there are stem cells in adipose tissue? (What are stem cells? What are the different kinds of stem cells?)
YES! And in fact, adipose tissue contains the largest store of stem cells in the adult human body. The only other place from where stem cells can be in the adult body is in bone marrow (bone marrow aspirate cells; BMAC), although compared to adipose tissue (adipose-derive stem cells, ADSCs), which may contain up to 5% stem cells in some people, it is much less abundant in bone marrow (less than 0.01% of all cells), and the quantity of these cells decrease with age, not to mention that the harvesting process for bone marrow is a lot more invasive and painful compared to harvesting of stem cells from adipose tissue.
Unfortunately, the words “stem cells” have a certain stigma attached to them, especially in the eyes of the FDA. Why? To answer this question, we must first explore what stem cells are, and how they are classified.
Back in the late 1990’s, researchers figured out a way to extract embryonic stem cells (ESC’s) from a developing embryo and grow them in a laboratory setting. At the time, it was thought that this discovery was going to revolutionize the field of regenerative medicine. Unfortunately, this practice quickly drew criticism for several reasons, the biggest of which being the ethics of working with a developing embryo, so the idea was not really pursued in earnest, even until today.
In 2006, another group of researchers discovered a way around this, which was to take adult skin cells, called fibroblasts, and engineer them back into a stem cell state. These cells were called induced Pluripotent Stem Cells (iPSCs) and the lead researcher, Shinya Yamanaka, won the Nobel Prize for this work six years later. As one can imagine, this process was extremely costly, but this was not the only problem. Unfortunately, when these iPSC cells were injected into the spines of mice, a terrible outcome in the form of uncontrolled tumors, called teratomas, developed. For this reason, iPSCs also did not face much success in terms of clinical translation and actual use in humans. To date, less than 60 clinical trials have been performed on iPSC’s, none of which were in people, although that’s not to say that iPSC’s may not be the future, if researchers can circumvent the cancer-forming potential of these cells.
For these reasons, the FDA, in executing its role in ensuring public safety, has since taken a firm stance against stem cells, and rightfully so, because of these very real cancer risks. However, NOT ALL STEM CELLS ARE CREATED EQUAL!
One type of stem cell that’s largely flown under the radar, but has been gaining more and more traction lately, are adult stem stems, specifically, mesenchymal stem cells (both BMAC and ADSC are Mesenchymal Stem Cells; MSC’s). Unlike totipotent ESCs and pluripotent iPSCs, which can both differentiate, or change, into any type of cell in the body, mesenchymal stem cells can only change into a limited number of types of cells, such as fat, muscle, bone, and cartilage cells, to name a few, with the differentiation dependent upon the type of environment the cells are found in. As a result, they have a much higher safety margin compared to ESCs and iPSCs, and to date, of the 400+ clinical trials conducted with these cells, there has been few reports of adverse events, and no reports of development of cancer due to treating patients with their own stem cells!
Nevertheless, despite the promising potential of adult MSC’s like BMAC and ADSC’s, the FDA is still cautious about the use of stem cells. However, per FDA guidelines set forth in 21CFR1271 and Sec. 361 of the Public Health Act, fat grafting procedures, enabled by our suite of products, are compliant as long as the tissue grafted is AUTOLOGOUS (belongs to the same person), MINIMALLY MANIPULATED (injected right back into the patient within a certain window and not manipulated in a way that changes the properties of the tissue, such as taking out a cell fraction and growing them in a laboratory setting prior to reinjection), and applied in a HOMOLOGOUS manner (using fat as fat, and not purely for it’s regenerative potential).
Used this way, adipose tissue (fat) transfer can be applied for regenerative medicine procedures, all the while adhering to FDA guidelines.