In this study, we investigated the potential effect of the adipose-derived stromal vascular fraction (SVF) on androgenetic alopecia (AGA). Adipose tissue being a biologically active complex is important for tissue engineering and regenerative medicine applications14. In the current study, we used SVF which is a mixture of several types of cells including ASCs. Tolerability and safety of using SVF was determined, and no adverse side effects were reported in any patient.
In AGA patients, the basic concept of using SVF is to replenish stem cell repository in the bulge region of hair follicles by homing and to stimulate growth cycle of stem cells by paracrine effects17. SVF is known to be one of the most accessible sources of MSCs and has recently emerged as a new therapeutic option for degenerative conditions.18 With a primary role in the homeostasis of organs and tissues, MSCs maintain the stem cell niche, help tissue recovery after injuries, and ensure healthy aging13. In addition to replacing damaged cells in affected tissues, SVF has beneficial effects through its paracrine action via various cytokines and growth factors 18, 20. A recent study showed the synergic effect of PRP and micrografts enriched with autologous human follicle MSCs on AGA10,11. In comparison with PRP or micrografts, ADSC-based therapies have more published evidence of their effect on hair regrowth through clinical trials21.
The therapeutic role of SVF was assessed using parameters such as hair density, hair thickness, photographs, and status of scalp. In this case series, the potential effect of a single dose of SVF on AGA was tested. There was a significant increase of hair density in the treated site compared to the nontreated site. The average number of hair thickness of the treated side was significantly increased at 6 months post injection (P < 0.05). Furthermore, nonfunctioning hair follicles filled with hyper-keartotic plugs22, up to today assumed incapable of forming new hair, showed more significant improvement in the score of keratin of scalp in the treated side as compared to the nontreated side (p = 0.032). No side effects were noted after treatment.
Currently, only a few FDA-approved agents for AGA treatment are available22. Finasteride and minoxidil, either as monotherapy or in combination, are recommended as the gold standard treatment for AGA23,24. The current clinical practice guidelines on this treatment include finasteride 1 mg, dutasteride 0.5 mg for men, and minoxidil 2% solution or minoxidil 3% foam for women. Lucky et al25 revealed that hair density was increased by 17.3% by the application of 5% minoxidil twice per day for 48 weeks in female AGA patients. Also, 157 male patients with AGA treated with 5% topical minoxidil for 48 weeks had increased hair density and thickness by only 12.3%26,27. In our study, hair density was increased by 48.11%, and hair thickness was increased by 50% by one application of SVF treatment. SVF-based therapeutics allow for more options for female patients with AGA. Moreover, there is increasing evidence of the positive outcomes of ADSC treatment in combination with human follicle stem cells in hair regrowth.27,54,55 Although many laboratory experiments and animal studies have investigated the effects of ADSC on hair growth and identified its positive effect in promoting hair regeneration, only a few clinical trials have investigated the effects of ADSC-based therapies on the hair cycle in humans28,29.
According to recent data, promotion of hair growth via ADSCs can be enhanced by combining it with minoxidil, which stimulates the motility of ADSCs and increases the secretion of growth factors and paracrine signaling29. This result might suggest that ASCs migrated close to the injection site and enabled hair growth. Alternatively, ASCs might be capable of migration by making use of the local circulation. The differentiation as well as production and secretion of growth factors that activate neighboring cells are also mentioned as relevant functions of ADSCs. Compared with healthy individuals, in patients with AGA, the expression of vascular endothelial growth factor (VEGF), keratinocyte growth factor (KGF), epidermal Growth Factor (EGF), and transforming growth factor-β1 (TGF-β1) is disturbed in the hair follicles, and this affects the hair cycle differently depending on the age and sex30. Therefore, it is clinically important to personalize the optimal concentration, dosage, and frequency of adipose derived stem cell (ADSC)-based therapies. Indeed, clinical trials have shown that the efficacy of ADSC-based therapies in AGA treatment is dependent of a number of different variables, such as the type of formulation, presence of combined treatments, and delivery methods of ADSC-based therapies,22,31,33.
The proposed strategy can provide not only a treatment for AGA patients but also be helpful in the development and success of tissue engineering and regenerative medicine applications. In addition, the results of this study will open a new avenue in dermatology for the treatment of patients with AGA. Taking everything into consideration, we believe that the hallmarks of tissue damage are also present in AGA. Addressing the combination of both cellular as well as intercellular aspects of wound repair as an alternative treatment of AGA seems to deserve further attention.