Regenerative Medicine and Its Implications in Aesthetic Medicine

by Sharon McQuillan, MD

Regenerative medicine, through the use of adult stem cells, is a revolutionary approach for the treatment of many of the degenerative conditions that occur with aging, including the appearance of aging. Regenerative medicine brings together nearly all fields of science and holds the realistic promise of repairing damaged tissue by harnessing the body’s own ability to heal itself. In particular, cellular medicine has the potential to treat previously incurable diseases such as diabetes, heart disease, COPD (chronic obstructive pulmonary disease), renal failure, and arthritis. Most every degenerative disease is currently being studied for potential treatment with stem cell therapy. Regenerative medicine has also attracted attention for its newfound ability to improve aesthetic enhancements such as autologous fat grafting and skin rejuvenation.

The use of adipose-derived mesenchymal stem cells (ADSCs) is a natural progression in aesthetic medicine. Adipose-derived stem cells present a clear advantage in that subcutaneous fat is readily available in the majority of patients and can be easily isolated under local anesthesia. ADSCs can be found in abundant quantities within fat and have been reported to be very similar to mesenchymal stem cells that are isolated from bone marrow (Bunnell 2008). The number of stem cells harvested from fat can be up to 500 times higher than bone marrow (Meliga 2007). They can be safely and effectively transplanted immediately after harvesting and isolation, and the procedure can be performed in an in-office setting. ADSCs have proliferative potential and the ability to differentiate into adipocytes, blood vessels, cartilage, bone, and cardiac tissue, among others. Several mechanisms have been associated with the beneficial effects of ADSCs, including their ability to reduce inflammation and promote tissue healing through local secretion of cytokines and growth factors, which can serve to recruit stem cells from other tissues to the affected tissue to facilitate repair and healing.

One of the newest and most successful applications of stem cells involves cell-assisted lipotransfer. Although fat grafting has been practiced for over 100 years, consensus on a standardized method for harvesting and fat graft survival has yet to emerge. A renewed interest in utilizing fat as the ideal filler stems from an increased number of liposuction procedures performed, recent trends in revolumization, and a new appreciation for the regenerative potential of stem cells contained in the lipoaspirate. In cell-assisted lipotransfer (or CAL), autologous adipose-derived stem cells are used in combination with autologous fat transfer. Once removed, half of the volume of aspirated fat is processed for the isolation of ADSC, while the other half is prepared for grafting. The stem cells and processed fat are combined and injected into various target areas, such as the face, breast, and gluteal. The addition of stem cells to fat that is used for autologous transfer enhances angiogenesis, improves fat graft liability, and reduces postoperative atrophy.

There are many mechanisms involved in cell-assisted lipotransfer. ADSCs involved in the repair process after fat transfer play a key role in adipogenesis and angiogenesis. With lipografting, the recipient tissue is injured and bleeding occurs. Cytokines released by platelets include platelet derived growth factor (PDGF), endothelial growth factor (EGF), and transforming growth factor beta (TGF-β). The grafted nonvascularized adipose tissue is placed under hypoxia and is temporarily fed by surrounding host tissue until direct capillary attachment is formed. In response to tissue trauma, basic fibroblast growth factor is released from the extracellular matrix and dying cells. Surviving adipocytes die within a few months after transplantation and are replaced with next-generation cells. The surviving fat grafts are theorized to turn over within 2 to 3 months after transplantation. The number of ADSCs may affect the replacement process and postoperative atrophy of grafted fat, which commonly occurs during the first six months after grafting (Yoshimura K. Regen Med. 2009). The research published by Yoshimura et al. suggests a strong correlation between the number of viable ADSCs contained in the fat graft and the graft retention.

This advancement in autologous fat transfer makes the procedure more predictable and reliable, which is especially important in large-volume grafts such as breast and gluteal augmentation. Loss of significant volume in a breast or gluteal fat graft may leave the patient with inadequate donor fat for a second treatment. Matsumoto et al. showed a 35% increase in graft survival at 6 months when stem cells were added to the graft. Additionally, the transplanted cells expressed vascular endothelial cell markers. Yoshimura et al. performed and published the transplantation of stem–cell supplemented adipose tissue (CAL) of the breast in 15 patients. Overall, clinical results were very satisfactory, with no major abnormalities seen on magnetic resonance imaging or mammogram after 12 months. Postoperative atrophy of the injected fat was minimal and did not change substantially after 2 months. Surviving fat volume at 12 months was 155 ± 50 ml (right) and 143 ± 80 ml (left) following lipoinjection from an initial mean of 264 ml. Their results suggest that CAL is a suitable methodology as an option for breast enhancement.

Other aesthetic applications for adipose-derived stem cells include improving skin quality, skin repair, wound healing, and wrinkle reduction. ADSCs produce cytokines including VEGF, HGF, IGF, PDGF, and TGF-β, which provide a regenerative effect on the skin. These growth factors activate and increase migration of dermal fibroblasts which mediate collagen secretion. Kim et al. showed that these activated dermal fibroblasts also have an antiwrinkling effect. The ADSCs and their soluble factors reduce UVB-induced apoptosis and stimulate collagen synthesis.

Evidence suggests that ADSCs participate in angiogenesis and wound healing. ADSCs isolated from human adipose tissue are known to secrete VEGF, HGF, TGF-β. The levels of VEGF secretion increased 5-fold when ADSCs were cultured in hypoxic conditions. These findings suggest that autologous delivery of ADSCs, which are regulated by hypoxia enhance angiogenesis (Nambu et al. Ann Plast Surg. 2009). Additionally, ADSCs express pericyte lineage markers, reside in a periendothelial location, and stabilize endothelial networks (Traktuev DO et al. Circ Res. 2008).

Sydney Coleman observed that fat grafts improve surrounding tissue. Coleman also noted improvement in the quality of aging skin and scars, as well as improvement in conditions such as radiation damage and chronic ulceration. Histology of the tissue showed improvement of scar by collagen deposition, local hypervascularity, and dermal hyperplasia (Coleman SR. Plast Reconstr Surg. 2006). Mojallal et al. studied the improvement of skin quality after fat grafting via clinical observation and animal study. Clinical observation revealed a volumetric improvement as well as skin improvements in the grafted area, including skin texture, pore size, suppleness, skin color, and scar quality. Histological analysis from preclinical studies showed the presence of mature adipocytes in large quantities. Additionally, thickening of the extracellular matrix surrounding fat tissue and dermis can be seen after fat grafting. The thickening of the extracellular matrix was attributed to an increase in type I collagen. We now know that these qualitative improvements are due to the presence of stem cells wihin the fat grafts providing growth factors and improved circulation

Stem cells have also been used for facial skin rejuvenation by injection. Park et al. utilized ADSCs injected in mesotherapy-like fashion for skin rejuvenation. A patient with photodamaged skin was injected intradermally with autologous processed lipoaspirate containing 30% ADSCs twice in a two-week period. The patient showed improvement of skin texture and wrinkles two months postprocedure. Dermal thickness results were shown histologically via high frequency ultrasonograph.

The increased focus on regenerative medicine has resulted in a variety of topical products containing “stem cells” in the marketplace. Many of these skin-care products are created using peptides or enzymes that help stimulate the skin’s stem cells or protect the stem cells from damage or deterioration. Other products utilize plant-based stem cells to promote healing and anti-aging effects. The plant stem cells are derived from plants such as the Uttwiler Spätlauber apple tree, edelweiss plant, and the date palm. Currently, there is little to no clinical evidence to support the claims of these products and it should be noted that if any of these products actually altered the cell structure, it would require FDA approval.

Studies are under way in our clinics for cell-assisted laser resurfacing. Cell-assisted laser resurfacing combines the use of fractional ablative laser resurfacing with the topical application of autologous ADSCs applied in a cell medium immediately posttreatment. Histologic changes observed following fractional ablative resurfacing demonstrate neocollagenesis six weeks post-operatively via dermal fibroblast and growth factor activation. The positive effect of ADSCs in wound healing have been observed. It is theorized that the combination of these two treatment modalities will result in a more pronounced fading of wrinkles and photodamage with a shorter healing time.

In order to integrate stem cell medicine into a physician practice, it is important to have the appropriate education/training and to have a process that is fully validated, provides a consistent cellular product, and complies with the current regulatory environment. Providing stem cell therapy at the point of care is also crucial as stem cell viability and potency diminish significantly over time.

The accepted method of adipose-derived mesenchymal stem cell isolation involves tumescent liposuction, cell washing to remove hematopoietic cells, enzymatic digestion, centrifugation to separate and isolate the stromal vascular fraction (SVF), filtration, and the preparation of the SVF in final suspension. ADSC can be harvested and isolated easily, abundantly, and with minimal patient discomfort in a 90-minute in-office procedure.

In autologous fat transfer, the harvesting method has an effect on the fat graft viability as well as the stem cell yield. Stem cell yields are affected by the surgical technique employed, the location from which the fat is harvested, and the time and concentration of enzymatic digestion utilized. The abdomen is the preferred collection site for ADSCs in terms of cell yield and viability, although other sites can be used successfully (Cell Tissue Res. 2008). There are many factors that matter when harvesting adipose tissue, including the suction pressure, type and size of cannula used, the manner in which the fat is processed, and the type of system employed. We have had the best success with a collection method utilizing less than 350 mm Hg suction pressure, cannulas no smaller than 3 mm in a closed system under sterile technique, with decantation rather than centrifugation. This method results in a gentler treatment of the fat, leading to higher cell viability.

(use processing photos here)

This established cell isolation technique provides a consistent, safe, and compliant method for processing adipose-derived mesenchymal stem cells. We are collecting approximately 1 million cells per cc of fat extracted. This procedure has been validated via reproducibility and robustness analysis. The process consistently produces predetermined acceptance criteria, making it easy to duplicate in a medical office setting. We are utilizing materials that are produced according to cGMP regulations or regulated as clinical grade.

(Place yield and results graphs here)

Offering stem cell therapies to patients not only requires procedural competence, but a thorough understanding of the regulatory considerations involved. Any technique employed for obtaining stem cells must adhere to the current code of federal regulations for use in a physician’s practice. The method described meets the federal code of regulations concerning autologous, homologous used of minimally manipulated cells at the point of care, and is therefore not regulated by the FDA, but is considered the practice of medicine. According to FDA CFR title 21 part 1271, which concerns the regulation of human cells, tissues, and cellular and tissue-based products, physicians are not required to comply with the requirements of FDA regulation if the physician removes cell products and implants them into the same individual during the same procedure. Additionally, the cells used must be minimally manipulated, meaning that the processing used does not alter the relevant biological characteristics of the cells.

Until now, one of the barriers to implementation of cell-assisted therapies into clinical practice has been the lack of an affordable, validated method for the isolation of ADSC from a lipoaspirate. The automated methods undergoing FDA trials are not currently permitted for patient clinical use except under clinical trials or IRB. The retail price of these devices once FDA approved is projected to be $70,000-90,000 with a consumable cost between $1200 and $7500.

As the data suggest, stem cells possess enormous regenerative potential. Adipose stem cells can be harvested easily, abundantly, and with minimal patient discomfort. The potential applications are virtually limitless. Clinical applications for patients can be performed in a medical office setting safely, legally, and ethically using autologous adipose-derived stem cells. The manual laboratory method requires less than $6000 in equipment costs, 90 minutes per process, and yields approximately 1 million, 99% viable ADSCs per fat gram processed. Freshly processed cells are positive for cell markers CD34 and CD90, making them angiogenic and regenerative. This method meets the federal code of regulations as an autologous, homologous use of minimally manipulated cells at the point of care and is therefore not regulated by the FDA but is considered the practice of medicine. As aesthetic practitioners, we owe it to our patients to provide them only the safest and compliant methods in these cutting-edge treatments. Cosmetic practitioners know the value of fat as a filler; the next step is to utilize fat for its regenerative value both in the cosmetic arena and the traditional medical arena. One of most exciting things about adipose-derived stem cells is that we have only scratched the surface of their true potential. The coming years will bring forth amazing scientific discovery.

References

Bunnell B et al. Adipose-derived stem cells for regenerative medicine. Circ Res 2007;00:1249–1260.

Fontdevila J et al. Assessing the long-term viability of facial fat grafts: an objective measure using computed tomography. Aesth Surg J 2008;28:380–386.

Jeong JH. Adipose stem cells and skin repair. Cur Stem Cell Res & Ther 2010;5:137–140.

Kim W et al. Antiwrinkle effect of asipose-derived stem cell: activation of dermal fibroblast by secretory factors. J Derm Sci 2009;53:96–102.

Kurita M, Yoshimura K, et al. Influences of centrifugation on cells and tissues in liposuction aspirates: optimized centriguation for lipotransfer and cell isolation. Plast Reconstr Surg 2008;121:1033–1043.

Meliga E et al. Adipose-derived cells. Cell Transplantation 2007;16(9):963–970.

Mizuno H. Asipose-derived stem cells for tissue repair and regeneration: ten years of researcha and a literature review. J Nippon Med Sch 2009;76(2):56–66.

Mojallal et al. Improvement of skin quality after fat grafting: clinical observation and an animal study. Plast Reconstr Surg 2009;124:765–774.

Rehman M, March KL et al. Secretion of angiogenic and antiapoptice factors by human adipose stromal cells. Circ 2004;109:1292–1298.

Yoshimura K, Suga H, Eto E. Adipose-derived stem/progenitor cells: roles in adipose tissue remodeling and potential use for soft tissue augmentation. Regen Med 2009;4(2):265–273.

Yoshimura K et al. Cell-assisted lipotransfer for cosmetic breast augmentation: supportive use of adipose-derived stem/stromal cells. Aesth Plast Surg 2008;32(1):48–55.

Yoshimura K, Sato K, Noriyuki A, et al. Cell-assisted lipotransfer for facial lipoatrophy: efficacy of clinical use of adipose-derived cells. Dermatol Surg. 2006;34:1178–1185.

Sharon McQuillan, MD, is a board-certified physician who specialized in aesthetic, anti-aging, and regenerative medicine. She founded the Ageless Aestehtic Institute, the only level 4 ACCME-accredited aesthetic training program for medical professionals, in order to standardize and elevate the practice of aesthetic medicine. Dr. McQuillan has educated thousands of medical professionals in the art and science of aesthetic and anti-aging treatments for over a decade. Dr. McQuillan lectures internationally on aesthetic and regenerative medicine for many organizations and is the medical director of the Aesthetic Fellowship, hosted by the American Academy of Anti-Aging Medicine. In 2009, Dr. McQuillan formed the Ageless Regenerative Institute in conjunction with a team of experts in stem cell therapies. This expert team has developed an approved method and protocol for the harvesting and isolation of adipose-derived stem cells for autologous transplantation.