Autologous adipose-derived stem cells: Basic science, technique, and rationale for application in ulcer and wound healing

Long-term Results After Autologous Fat Transfer for Treatment of Chronic Lower Extremity Wounds

Autologous fat transfer may offer a simple and effective treatment option for chronic wound patients, delivering adipose-derived stem cells, with potent regenerative attributes. Nevertheless, the clinical benefit has not yet been sufficiently demonstrated. A total of 39 wound patients were treated with autologous fat transfer (AFT) and matched with a control group, according to the identified confounding variables "gender" and "method of defect closure." All data were acquired retrospectively. Primary outcome was "wound closure" and "reduction of wound size."After a follow-up of 48 weeks, there was no significant difference in primary outcome (wound closure P = .54) between both groups. The relative wound reduction after fat transfer was 69.9% ± 42.7% compared to 53.4% ± 106.8% in the control group (P = .91). Subgroup analysis of all patients, healed by secondary intention, revealed an increased wound size reduction (P = .03) and wound closure rate (P = .20) in the case group after 12 weeks. No adverse events were recorded. Fat grafting can reduce the wound size if left to secondary healing and may be considered individually for reconstructive purposes. A repeated application of autologous fat might be beneficial due to a temporary effect.

Effectiveness of Secretome from Human Umbilical Cord Mesenchymal Stem Cells in Gel (10% SM-hUCMSC Gel) for Chronic Wounds (Diabetic and Trophic Ulcer) - Phase 2 Clinical Trial

Background

Chronic wounds carry financial burdens and increase morbidity and mortality, especially in diabetic ulcers and Hansen's Morbus. More than 50% of chronic ulcers are difficult to heal with regular treatment and require new types of therapy such as the use of secretome of human umbilical cord mesenchymal stem cells (SM-hUCMSC).

Methods

This experimental study was carried out to see the effectiveness of using SM-hUCMSC in diabetic ulcers and Hansen's Morbus in four medical facilities (multicentre). The level of active secretion has been measured by default in 10% SM-hUCMSC gel, used as a treatment intervention. The primary outcome is wound healing in terms of the length, width, and extent of the wound. The secondary is the side effects of treatment 2 weeks after administration. Follow-up visits will be scheduled at 1 and 2 weeks post-treatment.

Results

Forty-one chronic ulcers successfully followed the study until the end. In patients with chronic ulcers, the mean ulcer length, width, and area were 1.60 (0,50-13,0), 1.3 (0,5-6,0), and 2.21 (0,25-78) cm square, respectively, before interventions and 1 (0-12), 0,8 (0-6,0), and 1 (0-72) square cm after interventions at the second follow-up. The change between the beginning and end of the intervention was significant (p-value <0.05).

Conclusion

The use of 10% SM-hUCMSC gel topically has been proven effective in accelerating the process of wound healing, especially chronic ulcers with side effects that are not present in this study.

Comparative analysis of mouse bone marrow and adipose tissue mesenchymal stem cells for critical limb ischemia cell therapy

INTRODUCTION

Critical limb ischemia (CLI) is the most advanced form of peripheral arterial disease (PAD) characterized by ischemic rest pain and non-healing ulcers. Currently, the standard therapy for CLI is the surgical reconstruction and endovascular therapy or limb amputation for patients with no treatment options. Neovasculogenesis induced by mesenchymal stem cells (MSCs) therapy is a promising approach to improve CLI. Owing to their angiogenic and immunomodulatory potential, MSCs are perfect candidates for the treatment of CLI. The purpose of this study was to determine and compare the in vitro and in vivo effects of allogeneic bone marrow mesenchymal stem cells (BM-MSCs) and adipose tissue mesenchymal stem cells (AT-MSCs) on CLI treatment.

METHODS

For the first step, BM-MSCs and AT-MSCs were isolated and characterized for the characteristic MSC phenotypes. Then, femoral artery ligation and total excision of the femoral artery were performed on C57BL/6 mice to create a CLI model. The cells were evaluated for their in vitro and in vivo biological characteristics for CLI cell therapy. In order to determine these characteristics, the following tests were performed: morphology, flow cytometry, differentiation to osteocyte and adipocyte, wound healing assay, and behavioral tests including Tarlov, Ischemia, Modified ischemia, Function and the grade of limb necrosis scores, donor cell survival assay, and histological analysis.

RESULTS

Our cellular and functional tests indicated that during 28 days after cell transplantation, BM-MSCs had a great effect on endothelial cell migration, muscle restructure, functional improvements, and neovascularization in ischemic tissues compared with AT-MSCs and control groups.

CONCLUSIONS

Allogeneic BM-MSC transplantation resulted in a more effective recovery from critical limb ischemia compared to AT-MSCs transplantation. In fact, BM-MSC transplantation could be considered as a promising therapy for diseases with insufficient angiogenesis including hindlimb ischemia.

Strategies and challenges in the treatment of chronic venous leg ulcers

Evaluating patients with chronic venous leg ulcers (CVLUs) is essential to find the underlying etiology. The basic tenets in managing CVLUs are to remove the etiological causes, to address systemic and metabolic conditions, to examine the ulcers and artery pulses, and to control wound infection with debridement and eliminating excessive pressure on the wound. The first-line treatments of CVLUs remain wound care, debridement, bed rest with leg elevation, and compression. Evidence to support the efficacy of silver-based dressings in healing CVLUs is unavailable. Hydrogen peroxide is harmful to the growth of granulation tissue in the wound. Surgery options include a high ligation with or without stripping or ablation of the GSVs depending on venous reflux or insufficiency. Yet, not all CVLUs are candidates for surgical treatment because of comorbidities. When standard care of wound for 4 wk failed to heal CVLUs effectively, use of advanced wound care should be considered based on the available evidence. Negative pressure wound therapy facilitates granulation tissue development, thereby helping closure of CVLUs. Autologous split-thickness skin grafting is still the gold standard approach to close huge CVLUs. Hair punch graft appears to have a better result than traditional hairless punch graft for CVLUs. Application of adipose tissue or placenta-derived mesenchymal stem cells is a promising therapy for wound healing. Autologous platelet-rich plasma provides an alternative strategy for surgery for safe and natural healing of the ulcer. The confirmative efficacy of current advanced ulcer therapies needs more robust evidence.

Strategies and challenges in the treatment of chronic venous leg ulcers

Evaluating patients with chronic venous leg ulcers (CVLUs) is essential to find the underlying etiology. The basic tenets in managing CVLUs are to remove the etiological causes, to address systemic and metabolic conditions, to examine the ulcers and artery pulses, and to control wound infection with debridement and eliminating excessive pressure on the wound. The first-line treatments of CVLUs remain wound care, debridement, bed rest with leg elevation, and compression. Evidence to support the efficacy of silver-based dressings in healing CVLUs is unavailable. Hydrogen peroxide is harmful to the growth of granulation tissue in the wound. Surgery options include a high ligation with or without stripping or ablation of the GSVs depending on venous reflux or insufficiency. Yet, not all CVLUs are candidates for surgical treatment because of comorbidities. When standard care of wound for 4 wk failed to heal CVLUs effectively, use of advanced wound care should be considered based on the available evidence. Negative pressure wound therapy facilitates granulation tissue development, thereby helping closure of CVLUs. Autologous split-thickness skin grafting is still the gold standard approach to close huge CVLUs. Hair punch graft appears to have a better result than traditional hairless punch graft for CVLUs. Application of adipose tissue or placenta-derived mesenchymal stem cells is a promising therapy for wound healing. Autologous platelet-rich plasma provides an alternative strategy for surgery for safe and natural healing of the ulcer. The confirmative efficacy of current advanced ulcer therapies needs more robust evidence.

Autotransplantation of the Adipose Tissue-Derived Mesenchymal Stromal Cells in Therapy of Venous Stasis Ulcers

Adipose tissue is a reliable source of mesenchymal stromal cells (MSC) for use in regenerative medicine. The aim of this pilot study was to describe the method, and assess the safety and the potential efficacy of transplantation of autologous adipose tissue-derived MSC for the treatment of chronic venous stasis ulcers. Study group consisted of 11 patients (mean age: 66.6 ± 9.5 years) with chronic venous stasis ulcers. Adipose tissue was harvested by tumescent-aspiration method. Stromal cells were separated using a dedicated closed system in a real-time bedside manner. The phenotype of cells was determined immediately after separation. Cell concentrate was implanted subcutaneously around the wound and the wound bed. All ulcers were assessed planimetrically before autotransplantation and every two weeks during the six-month follow-up. During the study all patients received standard local and general treatment. The preparation contained an average of 5.6 × 10⁶ ± 4 × 10⁶ cells per milliliter. The phenotype of 65-82% of transplanted cells expressed MSC markers: CD73⁺ CD90⁺ and CD34⁺. An improvement was observed in 75% of ulcers. The data showed highly significant negative correlation (p < 0.0001) between wound size and wound closure degree. There was no correlation of ulcer healing with other parameters evaluated, including age of the patients. No serious side effects were observed. Autotransplantation of adipose tissue stromal cells may be a safe and promising treatment method for chronic venous ulcers.

Effect of Collagen Scaffold With Bcl-2-Modified Adipose-Derived Stem Cells on Diabetic Mice Wound Healing

This study aimed at evaluating the effects of collagen scaffold with Bcl-2-modified adipose-derived stem cells (ADSCs) on wound repair in streptozotocin-induced diabetic mice. A round full thickness skin defect with a diameter of 7 mm was made in the mice model. The experimental mice were divided into 4 groups (n = 12 each): group A (control group), group B (scaffold group), group C (ADSCs-scaffold group), and group D (Bcl-2-ADSCs-scaffold group). On days 3, 7, 10, and 14 after surgery, characteristics of wound healing was observed, and wound tissues were sampled for histology characteristics via hematoxylin-eosin staining and immunohistochemical staining. Compared with other groups, the wound healing rate was significantly higher in group D a week after operation (P < .05). On the seventh day postoperation, group D exhibited higher blood vessel in the wounds granulation tissue than other groups according to results of hematoxylin-eosin staining and immunohistochemistry. In conclusion, these findings demonstrated that collagen scaffold with Bcl-2 modified ADSCs may effectively improve the wound healing process in diabetic mice.

Global guidelines trends and controversies in lower limb venous and lymphatic disease: Narrative literature revision and experts' opinions following the vWINter international meeting in Phlebology, Lymphology & Aesthetics, 23-25 January 2019

Guidelines are fundamental in addressing everyday clinical indications and in reporting the current evidence-based data of related scientific investigations. At the same time, a spatial and temporal issue can limit their value. Indeed, variability in the recommendations can be found both among the same nation different scientific societies and among different nations/continents. On the other side, Garcia already published in 2014 data showing how, after three years in average, one out of five recommendations gets outdated (Martinez Garcia LM, Sanabria AJ, Garcia Alvarez E, et al. The validity of recommendations from clinical guidelines: a survival analysis. CMAJ 2014;186(16):1211–1219). The present document reports a narrative literature revision on the major international recommendations in lower limb venous and lymphatic disease management, focusing on the different countries’ guidelines, trends and controversies from all the continents, while identifying new evidence-based data potentially influencing future guidelines. World renowned experts’ opinions are also provided. The document has been written following the recorded round tables scientific discussions held at the vWINter international meeting (22–26 January 2019; Cortina d’Ampezzo, Italy) and the pre- and post-meeting literature search performed by the leading experts.

A phase II randomized clinical trial for the treatment of recalcitrant chronic leg ulcers using centrifuged adipose tissue containing progenitor cells

BACKGROUND AIMS

Preclinical and observational reports indicate that adipose tissue (AT) is a safe and promising tool to treat non-healing venous leg ulcers (VLUs).

METHODS

From an initial cohort of 38 patients, 16 patients affected by non-healing VLUs were randomly allocated to the experimental arm (5 men and 3 women) and control arm (5 men and 3 women). In the experimental arm, wounds were treated by debridement, centrifuged adipose tissue (CAT), advanced dressings and compression. No experimental treatment (CAT) was administered to the control arm. We investigated the functional and the immunophenotypical features of the harvested CAT-derived stem cells. The primary outcome measures were healing time and safety of the cell treatment. Secondary outcomes were pain evaluated by numeric rating scale (NRS), complete wound healing at 24 weeks by Margolis Index and wound-healing process expressed in square centimeters per week. The various immunophenotypic and functional characteristics of CAT-derived stem cells were then correlated with the clinical outcomes.

RESULTS

No major adverse events were recorded. The healing time was significantly faster by applying CAT, 17.5 ± 7.0 weeks versus 24.5 ± 4.9 weeks recorded in the control arm (P < 0.036). NRS dropped after the first week to 2.7 ± 2.0 in the experimental arm versus 6.6 ± 3.0 in the control group (P < 0.01). The rate of healing at the 24th week was not significantly different between arms. Interestingly, we found a strong reverse correlation between the percent of CD34⁺/CD45^- non-hematopoietic cells, respectively, with the healing time (r = -0.894, P < 0.041) and NRS (r = -0.934, P < 0.020).

CONCLUSIONS

CAT is safe and may accelerate healing time in VLUs as well as reduce wound pain. The percentage of CD34⁺/CD45^- cells in stromal vascular fraction (SVF) seems to be a predictive biomarker of successful CAT treatment in these patients.

Autogenously derived regenerative cell therapy for venous leg ulcers

Introduction

Venous leg ulcers (VLUs), which arise from chronic venous insufficiency in the lower limbs, are a major cause of morbidity and significantly negatively impact patients’ health-related quality of life. Treatment of venous ulcers can be either conservative or surgical. Despite appropriate treatment, VLUs can be resistant to healing. Clinical results of treatment of venous foot ulcers with adipose-derived autologous stem cells, which did not improve despite the surgical treatment of the underlying venous pathology in the following case series, are reported.

Material and methods

Between April 2015 and January 2016, a total of 31 patients who had undergone surgery for underlying venous pathology but the venous ulcer had not healed were included in the study. The mean venous ulcer size was 3.6–6.2 cm (range: 2 to 8 cm by 3 to 9 cm). All patients were treated with adipose-derived autologous stem cells prepared using the MyStem Regenerative Adipose-Derived Stem Cell Purification Kit (MyStem LLC, USA). The ulcer diameter was measured and recorded in the third, sixth and twelfth months. The follow-up time was 12 months after ulcer healing.

Results

Eighteen ulcers demonstrated complete healing at the 12^th month. Thirteen ulcers exhibited serious contraction and epithelialization even though the ulcer was not completely closed. At the 12^th month, the ulcer size was reduced by 96.00 ±1.74% in these patients. The reduction in the ulcer area based on the month analyzed was significant (p = 0.001; p < 0.01). After the ulcers healed, the patients were followed for recurrence for one year. Recurrent ulcers were observed at the treated sites in 3 of 31 patients (9%). No adverse events, such as infection, inflammation, or tissue reactions, were observed.

Conclusions

Application of cell therapy in venous leg ulcer is currently used exclusively in patients not responding to the standard treatment. Autogenously derived regenerative cell therapy for VLUs can be considered as an additional treatment to primary surgical therapy.

[Effect of human adipose-derived stem cells on pressure ulcer healing in mouse]

Objective

To investigate the effect of human adipose-derived stem cells (hADSCs) on pressure ulcers in mouse.

Methods

The subcutaneous adipose tissue from voluntary donation was harvested. Then the hADSCs were isolated and cultured by mechanical isolation combined with typeⅠcollagenase digestion. The 3rd generation cells were identified by osteogenic, adipogenic, chondrogenic differentiations and flow cytometry. The platelet rich plasma (PRP) from peripheral blood donated by healthy volunteers was prepared by centrifugation. The pressure ulcer model was established in 45 C57BL/6 mice by two magnets pressurized the back skin, and randomly divided into 3 groups ( n=15). The wounds were injected with 100 μL of hADSCs (1×10 ⁶ cells) transfected with a green fluorescent protein (GFP)-carrying virus, 100 μL human PRP, and 100 μL PBS in hADSCs group, PRP group, and control group, respectively. The wound healing was observed after injection. The wound healing rate was calculated on the 5th, 9th, and 13th days. On the 5th, 11th, and 21st day, the specimens were stained with HE staing, Masson staining, and CD31 and S100 immunohistochemical staining to observe the vascular and nerve regeneration of the wound. In hADSCs group, fluorescence tracer method was used to observe the colonization and survival of the cells on the 11th day.

Results

The cultured cells were identified as hADSCs by induced differentiation and flow cytometry. The platelet counting was significantly higher in PRP group than in normal peripheral blood group ( t=5.781, P=0.029). General observation showed that the wound healing in hADSCs group was superior to those in PRP group and control group after injection. On the 5th, 9th, and 13th days, the wound healing rate in hADSCs group was significantly higher than those in PRP group and control group ( P<0.05). Histological observation showed that compared with PRP group and control group, inflammatory cell infiltration and inflammatory reaction were significantly reduced in hADSCs group, collagen deposition was significantly increased, and skin appendage regeneration was seen on the 21st day; at each time point, the expression of collagen was significantly higher in hADSCs group than in PRP group and control group ( P<0.05). Immunohistochemical staining showed that the number of neovascularization and the percentage of S100-positive cells in hADSCs group were significantly better than those in PRP group and control group on the 5th, 9th, and 13th days ( P<0.05). Fluorescent tracer method showed that the hADSCs could colonize the wound and survive during 11 days after injection.

Conclusion

Local transplantation of hADSCs can accelerate healing of pressure ulcer wounds in mice and improve healing quality by promoting revascularization and nerve regeneration.

Adipose-derived stem cells for treatment of chronic ulcers: current status

Chronic ulcers remain a difficult challenge in healthcare systems. While treatment options are limited, stem cells may be a novel alternative. Adipose-derived stem cells (ADSC) have become increasingly popular compared with bone marrow-derived stem cells as they are far easier to harvest. To summarize the current status of treating chronic ulcers with ADSC, this systematic review includes all clinical trials on the subject from PubMed and EmBase, as well as all registered clinical trials on ClinicalTrials.Gov. A total of nine clinical trials and fourteen registered trials were included. The studies were significantly different in terms of study design and patient population, and the overall quality of the studies was low to moderate. Despite the overall low study quality and the significant differences between the studies, some conclusions were consistent: ADSCs are safe, improve the healing of chronic ulcers, and reduce pain. As these results are consistent despite the shortcomings of the studies, they appear to highlight the efficacy of ADSCs in the treatment of chronic ulcers. Larger numbers of higher quality studies are needed to determine the precise role of ADSCs in treating chronic leg ulcers.