Mesenchymal Stem Cells and their Progenitor Cells (Fibroblasts) Derived from Skin are Superior to Bone Marrow Derived Mesenchymal Stem Cells
When addressing safety and efficacy concerns of stem cells, we must consider tissue-specific stem cells. Choosing the appropriate stem cell type to match the condition to be treated is critical not only to efficacy, but most importantly, safety of the therapeutic. Beyond the genetic and epigenetic factors that influence stem cell phenotype as embryonic stem cells differentiate into somatic stem cells, the immediate niche of the stem cell will have profound influence on the cell’s phenotype. Therefore, the appropriate use of adipose derived mesenchymal stem cells (ADSCs), and their related progenitor cells from the skin, fibroblasts, is optimal for skin care compared to bone marrow mesenchymal stem cells (BMSCs)
Let’s consider some of the problems BMSCs pose for developing skin care products. The complexity of the bone marrow (BM) niche can lead to many stem cell phenotypes, whether we consider hematopoietic stem cells (HSCs) or bone marrow mesenchymal stem cells (BMSCs). Here I will discuss the properties of BMSCs, not HSCs. Because of the complexity, many BMSC phenotypes exist, including disease causing phenotypes that are varied and hard to distinguish – a part of the problem in using BMSC for therapeutic development. This complication, unlike that for ADSCS, includes recirculated cells, particularly recirculated cancer cells. Once a tumor cell disseminates into the BM, the cancer cell often displays phenotypic characteristics of BMSCs rendering cancer cells difficult to distinguish from BMSCs. BM is a site of BMSCs that may differentiate into HSCs and recirculating blood cells that may differentiate into BMSCs [see Cardenas et al; Tondreau et al]. BMSCs are also found outside of the niche in peripheral blood and home into sites of injury and cancer tissue where they are educated into becoming a pro-cancerous phenotype. Recirculated melanoma and myelogenous leukemia cells in BM interact with BMSCs to change the phenotype of the BMSC to one that is cancer promoting by enhancing their proliferation, migration, and invasion and altering the production of proteins involved in the regulation of the cell cycle. Indeed, melanoma tumor cells start to disseminate to BM during the initial steps of tumor development. In breast cancer patients, detection of recirculated cancer cells that disseminated in BM predicts recurrence of the cancer. Cancer cells can fuse with BMSCs and change their phenotype, or release exosomes to change the phenotype of BMSCs to cancer promoting. Indeed breast tumor cells fuse spontaneously with bone marrow mesenchymal stem cells. This fusion may facilitate the exchange of cellular material from the cancer cell to the BMSC rendering the fused cell more oncogenic. Further, others have found the same result of this fusion and exchange of cellular material, which has been found to increase metastasis. For example, Li et al found that human hepatocellular carcinoma cells with a low metastatic potential exhibit a significantly increased metastatic potential following fusion with BMSCs in vitro and in xenograft studies. This means that the BMSCs and their molecules/exosomes, having been conditioned by tumor cells, were found to increase the probability of cancer in human patients. The various phenotypes of BMSCs, including the cancerous phenotypes are difficult to distinguish. In contrast, even ADSCs derived from cancer patients have been found to be safe for therapeutic development.
One of many reasons why ADSCs are preferred compared to BMSCs is that ADSCs express a low level of major histocompatibility complex (MHC) class I molecules and do not express MHC class II and costimulatory molecules. Even the exosomes of BMSCs express MHC class II proteins. These problems in BMSCs are amplified when using donor, allogeneic BMSCs that have been replicated many times, essentially aging the cells, during expansion to develop the therapeutic. This is in contradistinction to ADSCs. Critically, when comparing experimental data of BMSCs to ADSCs from the same human donor, “ADSCs have a “younger” phenotype,” according to stem cell scientists. Indeed, Burrow et al found that BMSCs have, among other negative attributes compared to ADSCs, an increased level of senescence compared to matched ADSCs. Senescent cells develop the senescence-associated secretory phenotype (SASP), a pro-inflammatory set of molecules where the local tissue effects of a SASP or specific SASP components have been found to be involved in a wide variety of age-related pathologies in vivo such as hyperplastic diseases, including cancer. Whereas the use of BMSC transplants has a history of medical adverse events, including the induction of cancer in the recipient (Maguire, 2019), fat grafting, along with its constituent ADSCs, have a long history of safety in medical procedures dating back to 1893 when the German surgeon Gustav Neuber transplanted adipose tissue from the arm to the orbit of the eye in an autologous procedure to fill the depressed space resulting from a postinfectious scar. Fat grafting’s long history of being safe, regardless of the harvesting techniques used in patients, has been recently reviewed by physician-scientists at Baylor College of Medicine. Furthermore, physician-scientists at Stanford University School of Medicine have recently reviewed the safety and efficacy of using ADSCs to augment the outcomes of autologous fat transfers. Scientists have found that ADSCs and fat grafting for treating breast cancer-related lymphedema is safe and efficacious during a one year follow-on, where patient-reported outcomes improved significantly with time. In a randomized, comparator-controlled, single-blind, parallel-group, multicenter study in which patients with diabetic foot ulcers were recruited consecutively from four centers, ADSCs in a hydrogel was compared to hydrogel control. Complete wound closure was achieved for 73% in the treatment group and 47% in the control group at week 8. Complete wound closure was achieved for 82% in the treatment group and 53% in the control group at week 12. The Kaplan–Meier (a non-parametric statistic used for small samples or for data without a normal distribution) median times to complete closure were 28.5 and 63.0 days for the treatment group and the control group, respectively. Treatment of patients undergoing radiotherapy with adult ADSCs from lipoaspirate were followed for 31 months and patients with “otherwise untreatable patients exhibiting initial irreversible functional damage” were found to have systematic improvement or remission of symptoms in all of those evaluated. In animal models with a full thickness skin wound, administration of ADSCs, either intravenously, intramuscularly, or topically, accelerates wound healing, with more rapid reepithelialization and increased granulation tissue formation, and topically applied the ADSCs improved skin wound healing by reducing inflammation through the induction of macrophage polarization from a pro-inflammatory (M1) to a pro-repair (M2) phenotype.
All in all, companies using BMSCs to develop their skin care products demonstrates a profound ignorance of the related science. Incompetence, and a greedy, lazy approach to serving the skin care market is demonstrated by those using bone marrow stem cells to develop skin care products that potentially damage their clients.




