Stem cell fat grafting is autotransplantation of adipose-derived stem cells (ADSCs) extracted from fat-abundant donor sites (i.e. thigh or stomach) to other areas such as the face, breast, and hip to reconstruct the operative areas into desirable shapes. ADSCs are multipotent stem cells found in adipose tissues, displaying similar differentiation potentials to bone marrow-derived mesenchymal stem cells (BM-MSCs).
The discovery of ADSCs has brought great advances to the field of regenerative medicine and aesthetic procedures.Whilst the use of embryonic stem cells was reconsidered for ethical reasons, ADSCs got attention from plastic surgeons owing to their characteristics such as pluripotent differentiation potential, paracrine activities, immunomodulatory functions, and homing effect.
Regardless of the numerous benefits, there are few side effects and oncology safety issues The rising investment in stem cell cosmetic therapy reflects the high expectation and demands especially in South Korea. Further research on the effectiveness of ADSCs grafting proposed that the aftermath of the therapy can be affected by the quality of stem cells and diet by fostering adequate conditions for stem cell growth and sufficient consumption of nutrients.
History of stem cell plastic surgery
Dr.James Thomson at the University of Wisconsin first isolated human embryonic stem cells in 1998. However, due to the ethical controversies regarding embryonic stem cells, the induced pluripotent stem cells (iPSCs) were proposed as the substitute. The remaining oncological concern of iPSCs was eased by suggesting adult stem cells as the most primary resource of regenerative medicine.
History of autologous fat grafting
The first isolation of mesenchymal stem cells from the bone marrow was done by Friednstein et al. in 1986 and considered as a primary clinical stem cell source. However, the painful acquisition and low cell yield limited further research. Then Zuk et al. isolated ADSCs and found it has same potentials as BM-MSCs. Although later other stem cells were identified from different parts of the human body, ADSCs was considered to be the safest as it was the easiest stem cell to isolate and did not require cell expansion. Thus ADSCs are still used as a primary source of fat transfer therapies.
The concept of autologous fat grafting was first suggested in 1893. The first report described that the adipose tissue without changing its structure was implanted to the adherent scars from osteomyelitis. The result was successful and soon widely used in different fields of aesthetic procedures such as breast augmentation and rhinoplasties.
In 1978, a liposuction procedure was invented to remove the excessive fat depositions. Later, Illouz found that this procedure is the ideal supplier of fat tissue and used impurified lipoaspirate as a transplant in 1983 and Fournier proposed a reinjection technique of aspirated fat.
The third period starts from 1994 when S.R. Coleman introduced the Coleman technique, which uses adipose tissue for lipids cell transfer. The lipoaspirate was centrifuged to separates the stromal vascular fraction(SVF) including ADSCs from blood, tissue, fluid, and lipids. Yet, the fat cell retention rate was varied from 30% to 95%. The first theory that explains graft survival is the Cell Survival Theory, which suggests that the transfer of viable adipocytes for adequate circulation enhances the survival rate and this can be done by developing the processing and injection techniques to minimize trauma.
The recent theory is the Host replacement theory that retention rate after fat grafting is determined by the ADSCs replacing adipocytes, as the successful ADSCs activation and replacement of adipocytes is related to the early death of transferred adipocytes in ischemic conditions.