Use of derived adipose stem cells to reduce complications of cutaneous scarring in smokers. An experimental model in rats

Abstract Purpose To evaluate the use of adipose-derived stem cells (ADSC) in reducing the necrosis area in an experimental model of cutaneous ischemic flap in rats submitted to subcutaneous nicotine injection to simulate a smoker patient. Methods In an experimental study, 30 rats were enrolled and divided into two experimental groups of 15 animals all submitted to a subcutaneous nicotine injection to create ischemic cutaneous flaps on their backs. Other 10 animals were used only to obtain adipose tissue derived stem cells (ADSC). The first group (n=15) received ADSC treatment at the end of surgery while the other group, the control (n=15), received no other interventions. After euthanasia, a decal was performed on the whole area of the flap, accurately defining the transition from necrosis to healthy region. Photos of all animals were collected and evaluated by scales standardized by Paint-Autocad- 2015 software to define the area of flap necrosis in each rat. Student T test was performed to compare the groups, considering a p< 0.05 significant. Data were analyzed using SPSS IBM® 18 version. Results Through the analysis of the images by the program Paint-Autocad-2015 and the area of decal obtained by the transparent sheet, we obtained a mean of 46% necrosis of the total area of the flap in the treatment group and 69.4% in the control group. In the descriptive analysis, a mean of 3.7 cm of necrosis CI 95% (3.2 - 4.2) was evident in the treatment group whereas a mean value of 5.56 CI 95% (5.2 - 5.9) was found in control group, with p value <0.001 for this comparison. Conclusion The application of adipose-derived stem cells reduces the percentage of necrosis in an experimental model of randomized cutaneous flap in rats submitted to subcutaneous nicotine injection.

Injectable Tissue-Engineered Soft Tissue for Tissue Augmentation

Soft tissue augmentation is a process of implanting tissues or materials to treat wrinkles or soft tissue defects in the body. Over the years, various materials have evolved to correct soft tissue defects, including a number of tissues and polymers. Autogenous dermis, autogenous fat, autogenous dermis-fat, allogenic dermis, synthetic implants, and fillers have been widely accepted for soft tissue augmentations. Tissue engineering technology has also been introduced and opened a new venue of opportunities in this field. In particular, a long-lasting filler consisting of hyaluronic acid filler and living human mesenchymal cells called "injectable tissue-engineered soft tissue" has been created and applied clinically, as this strategy has many advantages over conventional methods. Fibroblasts and adipose-derived stromal vascular fraction cells can be clinically used as injectable tissue-engineered soft tissue at present. In this review, information on the soft tissue augmentation method using the injectable tissue-engineered soft tissue is provided.

Effects of Platelet-Rich Plasma, Adipose-Derived Stem Cells, and Stromal Vascular Fraction on the Survival of Human Transplanted Adipose Tissue

Traditional adipose tissue transplantation has unpredictable viability and poor absorption rates. Recent studies have reported that treatment with platelet-rich plasma (PRP), adipose-derived stem cells (ASCs), and stromal vascular fraction (SVF) are related to increased survival of grafted adipose tissue. This study was the first simultaneous comparison of graft survival in combination with PRP, ASCs, and SVF. Adipose tissues were mixed with each other, injected subcutaneously into the back of nude mice, and evaluated at 4, 8, and 12 weeks. Human adipocytes were grossly maintained in the ASCs and SVF mixtures. Survival of the adipose tissues with PRP was observed at 4 weeks and with SVF at 8 and 12 weeks. At 12 weeks, volume reduction in the ASCs and SVF mixtures were 36.9% and 32.1%, respectively, which were significantly different from that of the control group without adjuvant treatment, 51.0%. Neovascular structures were rarely observed in any of the groups. Our results suggest that the technique of adding ASCs or SVF to transplanted adipose tissue might be more effective than the conventional grafting method. An autologous adipose tissue graft in combination with ASCs or SVF may potentially contribute to stabilization of engraftment.

Engraftment of human adipose derived stem cells delivered in a hyaluronic acid preparation in mice / Implante de células tronco do tecido adiposo humano numa preparação de ácido hialurônico em camundongos

PURPOSE: To evaluate the implant of human adipose derived stem cells (ADSC) delivered in hyaluronic acid gel (HA), injected in the subcutaneous of athymic mice. METHODS: Control implants -HA plus culture media was injected in the subcutaneous of the left sub scapular area of 12 athymic mice. ADSC implants: HA plus ADSC suspended in culture media was injected in the subcutaneous, at the contra lateral area, of the same animals. With eight weeks, animals were sacrificed and the recovered implants were processed for extraction of genomic DNA, and histological study by hematoxilin-eosin staining and immunufluorescence using anti human vimentin and anti von Willebrand factor antibodies. RESULTS: Controls: Not visualized at the injection site. An amorphous substance was observed in hematoxilin-eosin stained sections. Human vimentin and anti von Willebrand factor were not detected. No human DNA was detected. ADSC implants - A plug was visible at the site of injection. Fusiform cells were observed in sections stained by hematoxilin- eosin and both human vimentin and anti von Willebrand factor were detected by immunofluorescence. The presence of human DNA was confirmed. CONCLUSION: The delivery of human adipose derived stem cells in preparations of hyaluronic acid assured cells engraftment at the site of injection.

OBJETIVO: Avaliar o implante de células tronco do tecido adiposo humano (CTTAH) em gel de ácido hialurônico (AH), injetados no tecido subcutâneo de camundongos atímicos. MÉTODOS: Implantes controle - HA com meio de cultura foram injetados no tecido subcutâneo da região infraescapular esquerda de 12 camundongos atímicos. Implantes de CTTAH: HA com CTTAH suspensas em meio de cultura foi injetado no subcutâneo da região contra lateral, dos mesmos animais. Com oito semanas, os animais foram sacrificados e os implantes recuperados foram processados para extração de DNA genômico, estudo histológico por coloração por hematoxilina eosina e imnuoflurescência utilizando anticorpos anti vimentina humana e anti fator de von Willebrand. RESULTADOS: Controles - implantes não visualizados no local da injeção. Uma substância amorfa foi observada nos cortes corados por hematoxilina eosina. Vimentina humana e fator anti von Willebrand não foram identificados. DNA humano não foi detectado. Implantes de CTTAH - Uma massa era visível no local da injeção. Células fusiformes foram observadas nos corte corados com hematoxilina eosina. Tanto vimentina humana quanto fator de von Willebrand foram identificados pela imunofluorescência. A presença de DNA humano foi confirmada. CONCLUSÃO: O implante de células tronco do tecido adiposo humano em veículo de ácido hialurônico gel assegurou a manutenção das células no local do implante.

Effects of Adipose-derived Stromal Cells and of their Extract on Wound Healing in a Mouse Model

In this study, the authors investigated the effects of adipose-derived stromal cells (ADSCs) and of their extract on wound healing. After creating wound healing splint model on the backs of mice, ADSCs and their extract were applied. Wound healing rates were calculated at 3, 5, 7, 10, and 14 days after the wounding, and tissues were harvested at 7 and 14 days for histological analysis. Wound healing rates were significantly higher at 7, 10, and 14 days in the cell group than in the control, but in the cell extract group wound healing rates were significantly decreased (P<0.05). Histological scores and capillary densities in the cell group were significantly higher at 2 weeks (P<0.05). In the cell group, thick inflammatory cell infiltration and many capillaries were observed at 1 week, and thick epithelium and numerous large capillaries were observed at 2 weeks. The present study suggests that ADSCs accelerate wound healing as known, and the effects of ADSCs on wound healing may be due to replacing insufficient cells by differentiation of ADSCs in the wound and secreting growth factors by differentiated cells, and not due to the effect of factors within ADSCs.