Efficiency of stem cell based therapy in the treatment of diabetic foot ulcer: a meta-analysis

Stem Cell Therapy for Diabetic Foot: An Umbrella Review of Systematic Reviews and Meta-Analyses

Objective: This umbrella review aims to summarize and evaluate the evidence from current systematic reviews/meta-analyses (SRs/MAs) on the effectiveness of stem cell therapy for diabetic foot (DF). Approach: We conducted a comprehensive search in four databases for SRs/MAs that included randomized controlled trials (RCTs) on stem cell therapy for DF. Two separate researchers independently evaluated the methodological quality and evidence quality of the SRs/MAs that were included in the study. We conducted a quantitative synthesis of all RCTs included in the SRs/MAs to obtain objective and updated conclusions. Egger's test and sensitivity analysis are used to examine the reliability of the results. Results: This umbrella review includes eight SRs/MAs, and their methodological quality and evidence quality were all deemed unsatisfactory. Out of the 8 SRs/MAs, 26 RCTs were included, with a total corrected covered area of 21.4%, indicating a high degree of overlap. The test of super-significance did not yield any significant results. Our updated meta-analysis suggests that DF patients can benefit from stem cell therapy, as indicated by effectiveness in measures, including healing rate, amputation rate, ankle-brachial index, transcutaneous oxygen pressure, ulcer size reduction, complete healing time, pain-free walking distance, rest pain score, and new angiogenesis rate. Innovation: This study conducted a comprehensive evaluation and reanalysis of the current evidence regarding the effectiveness and safety of stem cell therapy for DF, which is the first of its kind. Conclusion: Based on the existing evidence, stem cell therapy is effective and safe for patients with DF.

Efficacy of stem cell therapy for diabetic foot: Clinical evidence from meta-analyses

To assess the clinical data on the effectiveness of stem cell therapy for diabetic foot (DF) based on recent systematic reviews and meta-analyses (SRs/MAs). SRs/MAs that evaluate the clinical evidence on the efficacy of stem cell therapy for DF were identified through a systematic search in public databases. The methodological quality and evidence quality of the included SRs/MAs were assessed separately by two researchers. Eight SRs/MAs were included in this analysis. Since there were no registered protocol or exclusion criteria for the included SRs/MAs, the methodological quality was rated as critically low. There was no high-quality evidence available for the outcomes, and the evidence quality ranged from critically low to moderate. Evidence degradation was most commonly caused by the risk of bias, followed by imprecision, publication bias and inconsistency. In conclusion, stem cell therapy may be effective for DF. However, this conclusion should be approached with caution, considering the quality of the supporting SRs/MAs.

The effect of negative pressure wound therapy on the outcome of diabetic foot ulcers: A meta-analysis

Negative pressure injury is one of the auxiliary methods of treating diabetes foot ulcers. It has been shown to be superior to conventional techniques in randomized controlled trials (RCTs). Nevertheless, the results of observational research are still scarce. A systematic review of RCTs and observations was carried out to evaluate the effectiveness and security of negative pressure wound therapy (NPWT) treatment for diabetes foot ulcers. Three English e-databases have been found for NPWT research. The meta-analyses of the comparative studies provided point estimates of results. Intermediate results were given as median and binary values were given in the form of odds ratios (OR). Seventeen trials, 13 RCTs and four randomized, controlled trials were found in the survey. Of these, 831 were treated with NPWT, 834 were treated with standard therapy. A total of 14 studies have been conducted to investigate the influence of NPWT on the healing of diabetic foot ulcers(DFU). In the study, NPWT was shown to speed up the healing of the wound in DFU patients(OR, 2.57; 95% CI, 1.72, 3.85 p < 0.0001). A subgroup analysis showed that NPWT was associated with an acceleration of the wound healing rate in 10 RCT trials (OR, 2.48; 95% CI, 1.58, 3.89 p < 0.001). In the four nRCT trials, NPWT was also shown to speed up the healing of the wound(OR, 2.95; 95% CI, 1.03, 8.42 p = 0.04). In 11 studies, the influence of NPWT on amputations of diabetes mellitus (DM) foot ulcers was investigated. The results showed that NPWT was associated with a reduction in amputations (OR, 0.53; 95% CI, 0.37, 0.74 p = 0.0002).In a subgroup of RCT trials, nine RCT trials showed a reduction in amputations(OR, 0.61; 95% CI, 0.43, 0.87 p = 0.007). In both nRCT trials, NPWT also showed a reduction in amputations (OR, 0.03; 95% CI, 0.00, 0.24 p = 0.001). Generally speaking, NPWT can help to heal the wound and lower the risk of amputations in people with diabetes. The subgroup analysis showed similar results for the RCT and non-RCT trials. NPWT can be used to treat diabetes foot ulcers caused by diabetes.

Effect of Chinese herbal compound dressings in treating patients with diabetic foot ulcers: A meta-analysis

This meta-analysis aims to systematically investigate the clinical efficacy of Chinese herbal compound dressings in treating patients with diabetic foot ulcers (DFUs). A comprehensive computerised search was conducted in databases including PubMed, Embase, Google Scholar, Cochrane Library, China National Knowledge Infrastructure, and Wanfang databases, from database inception to November 2023, to identify randomised controlled trials (RCTs) concerning the use of Chinese herbal compound dressings in patients with DFU. Two researchers independently screened the literature, extracted data, and assessed the quality based on inclusion and exclusion criteria. Data analysis was performed using Stata 17.0 software. Overall, 18 RCTs involving 1405 DFU patients were included. The analysis indicated that compared to the control group, the group treated with Chinese herbal compound dressings had significantly shorter ulcer healing time (standardised mean difference [SMD] = -2.49, 95% confidence interval [CI]: -3.53 to -1.46, p < 0.001), reduced ulcer surface area (SMD = -3.38, 95% CI: -4.67 to -2.09, p < 0.001), and higher healing rates (odds ratio [OR] = 2.24, 95% CI: 1.72-2.92, p < 0.001) as well as overall effectiveness rates (OR = 4.56, 95% CI: 3.10-6.71, p < 0.001). This study demonstrates that the external application of Chinese herbal compound dressings in patients with DFU can significantly shorten the ulcer healing time and improve wound healing rates.

Effectiveness of Stem Cell Therapy for Diabetic Foot Ulcers: A Systematic Review and GRADE Compliant Bootstrapped Meta-Analysis of Randomized Clinical Trials

Diabetic foot (DF) represents a severe complication of diabetes mellitus, imposing substantial psychological and economic burdens on affected individuals. This investigation sought to assess the therapeutic efficacy of stem cell interventions in the management of DF complications. A comprehensive systematic search across PubMed, Embase, CINAHL, Scopus, and the Cochrane library databases was conducted to identify pertinent studies for meta-analysis. Outcome measures encompassed ulcer or wound healing rates, amputation rates, angiogenesis, ankle-brachial index (ABI), and pain-free walking distance. Dichotomous outcomes were expressed as risk differences (RDs) with 95% confidence intervals (CIs), while continuous data were articulated as standardized mean differences (SMDs) with corresponding 95% CIs. Statistical analyses were executed using RevMan 5.3 and Open Meta, with bootstrapped meta-analysis conducted through OpenMEE software. A total of 20 studies, comprising 24 arms and involving 1304 participants, were incorporated into the meta-analysis. The findings revealed that stem cell therapy exhibited superior efficacy compared to conventional interventions in terms of ulcer or wound healing rate [RD = 0.36 (0.28, 0.43)], pain-free walking distance [SMD = 1.27 (0.89, 1.65)], ABI [SMD = 0.61 (0.33, 0.88)], and new vessel development [RD = 0.48 (0.23, 0.78)], while concurrently reducing the amputation rate significantly [RD = -0.19 (-0.25, -0.12)]. Furthermore, no statistically significant difference in adverse events was observed [RD -0.07 (-0.16, 0.02)]. The Grading of Recommendations, Assessment, Development, and Evaluation assessment indicated varying levels of evidence certainty, ranging from very low to moderate, for different outcomes. Bootstrapping analysis substantiated the precision of the results. The meta-analysis underscores the significant superiority of stem cell therapy over conventional approaches in treating DF complications. Future investigations should prioritize large-scale, randomized, double-blind, placebo-controlled, multicenter trials, incorporating rigorous long-term follow-up protocols. These studies are essential for elucidating the optimal cell types and therapeutic parameters that contribute to the most effective treatment strategies for DF management.

Acellular Dermal Matrix for Treatment of Diabetic Foot Ulcer: An Overview of Systematic Reviews

Aims: To evaluate the reliability of the methodological quality and outcome measures of systematic reviews (SRs)/metaanalyses (MAs) of the acellular dermal matrix (ADM) for diabetic foot ulcer (DFU). Methods: We searched and retrieved SRs and MAs on the application of ADM for DFU from PubMed, Web of Science, The Cochrane Library, EMBASE, CNKI, CBM, WanFang, and VIP databases. We employed AMSTAR 2 to assess methodological quality, Grading of Recommendations, Assessment, Development and Evaluation (GRADE) system to grade, and the strength of evidence of included SRs/MAs. We excluded the overlapping randomized controlled trials (RCTs) and conducted a re-MA of the primary RCTs. Results: A total of 7 SRs/MAs were included. Results from the AMSTAR 2 evaluation revealed a low overall quality; the GRADE system showed that the evidence was of moderate to very low quality. Our re-MA showed that ADM was superior to standard of care (SOC), with regards to complete wound healing rate at 12 weeks (RR = 1.74, 95% CI:1.34-2.25, P < .0001), complete wound healing rate at 16 weeks (RR = 1.50, 95% CI: 1.26-1.77, P ＜ .00001); healing time (MD = -2.06, 95% CI: -2.57 to -1.54, P < .00001) and adverse events (RR = 0.62, 95% CI: 0.49-0.80, P = .0002). However, a consensus has not yet been reached between ADM and SOC groups with regard to outcome indicators of the reduction of ulcer area and quality of life; and subgroup analyses showed no statistically significant differences between the xenograft ADM and SOC groups (RR = 1.36, 95% CI: 0.95-1.93, P = .09) at 12 weeks. Conclusion: Current evidence suggests that ADM is more effective than the standard of care in the treatment of DFU, particularly for full-thickness, noninfected, and nonischemic foot ulcers, but with low evidence quality. Therefore, the results of this overview should be interpreted dialectically and prudently, and the role of ADM in DFU needs further exploration.

Innovations in Stem Cell Therapy for Diabetic Wound Healing

Significance: The global burden of diabetic wounds, particularly diabetic foot ulcers, continues to have large economic and social impact throughout the world. Current strategies are not sufficient to overcome this burden of disease. Finding newer, more advanced regenerative cell and tissue-based strategies to reduce morbidity remains paramount. Recent Advances: Recent advances in stem cell therapies are discussed. We also highlight the practical issues of translating these advancing technologies into the clinical setting. Critical Issues: We discuss the use of somatic and induced pluripotent stem cells and the stromal vascular fraction, as well as innovations, including the use of 3D bioprinting of skin. We also explore related issues of using regenerative techniques in clinical practice, including the current regulatory landscape and translatability of in vivo research. Future Directions: Advances in stem cell manipulation showcase the best therapeutic resources available to enhance mechanisms of wound healing such as angiogenesis, cell proliferation, and collagen synthesis; potential methods include changing the scaffold microenvironment, including relative oxygen tension, and the use of gene modification and nanotechnology. Secretome engineering, particularly the use of extracellular vesicles, may be another potential cell-derived therapeutic that may enable use of cell-free translational therapy.

Tissue Engineering-Based Strategies for Diabetic Foot Ulcer Management

Significance: Diabetic foot ulcers (DFU) are a mounting problem with the increasingly frail population. Injuries that would otherwise heal are kept open by risk factors such as diabetes, obesity, and age-related conditions, which interferes with the natural wound healing processes. Recent Advances: This review summarizes recent advancements in the field of tissue engineering for the treatment of DFUs. FDA-approved approaches, including signaling-based therapies, stem cell therapies, and skin substitutes are summarized and cutting-edge experimental technologies that have the potential to manage chronic wounds, such as skin printing, skin organogenesis, skin self-assembly, and prevascularization, are discussed. Critical Issues: The standard of care for chronic wounds involves wound debridement, wound dressings, and resolving the underlying cause such as lowering the glycemic index and reducing wound pressure. Current DFU treatments are limited by low wound closure rates and poor regrown skin quality. New adjuvant therapies that facilitate wound closure in place of or in conjunction with standard care are critically needed. Future Directions: Tissue engineering strategies are limited by the plasticity of adult human cells. In addition to traditional techniques, genetic modification, although currently an emerging technology, has the potential to unlock human regeneration and can be incorporated in future therapeutics.

Potential of stem cells for treating infected Diabetic Foot Wounds and Ulcers: a systematic review

Infected diabetic foot ulcers (iDFUs) cause great concern, as they generally heal poorly and are precursive of diabetic-related foot amputation and even death. Scientists have tested various techniques in attempts to ascertain the best treatment for iDFUs; however, the results have remained inconclusive. Stem cell therapy (SCT) appears to improve iDFU through its antimicrobial impacts, yet cogent information regarding the repair of iDFUs with SCT is lacking. Herein, published articles are evaluated to report coherent information about the antimicrobial effects of SCT on the repair of iDFUs in diabetic animals and humans. In this systematic review, we searched the Scopus, Medline, Google Scholar, and Web of Science databases for relevant full-text English language articles published from 2000 to 2022 that described stem cell antimicrobial treatments, infected diabetic wounds, or ulcers. Ultimately, six preclinical and five clinical studies pertaining to the effectiveness of SCT on healing infected diabetic wounds or ulcers were selected. Some of the human studies confirmed that SCT is a promising therapy for diabetic wounds and ulcers. Notably, more controlled studies performed on animal models revealed that stem cells combined with a biostimulator such as photobiomodulation decreased colony forming units and hastened healing in infected diabetic wounds. Moreover, stem cells alone had lower therapeutic impact than when combined with a biostimulant.

Topical and intravenous administration of human umbilical cord mesenchymal stem cells in patients with diabetic foot ulcer and peripheral arterial disease: a phase I pilot study with a 3-year follow-up

Background

Diabetic foot ulcer (DFU) is a serious chronic complication of diabetes mellitus that contributes to 85% of nontraumatic lower extremity amputations in diabetic patients. Preliminary clinical benefits have been shown in treatments based on mesenchymal stem cells for patients with DFU or peripheral arterial disease (PAD). However, the long-term safety and benefits are unclear for patients with both DFU and PAD who are not amenable to surgical revascularization.

Methods

In this phase I pilot study, 14 patients with PAD and incurable DFU were enrolled to assess the safety and efficacy of human umbilical cord mesenchymal stem cell (hUC-MSC) administration based on conservative treatments. All patients received topical and intravenous administrations of hUC-MSCs at a dosage of 2 × 10⁵ cells/kg with an upper limit of 1 × 10⁷ cells for each dose. The adverse events during treatment and follow-up were documented for safety assessments. The therapeutic efficacy was assessed by ulcer healing status, recurrence rate, and 3-year amputation-free rate in the follow-up phase.

Results

The safety profiles were favorable. Only 2 cases of transient fever were observed within 3 days after transfusion and considered possibly related to hUC-MSC administration intravenously. Ulcer disclosure was achieved for more than 95% of the lesion area for all patients within 1.5 months after treatment. The symptoms of chronic limb ischaemia were alleviated along with a decrease in Wagner scores, Rutherford grades, and visual analogue scale scores. No direct evidence was observed to indicate the alleviation of the obstruction in the main vessels of target limbs based on computed tomography angiography. The duration of rehospitalization for DFU was 2.0 ± 0.6 years. All of the patients survived without amputation due to the recurrence of DFU within 3 years after treatments.

Conclusions

Based on the current pilot study, the preliminary clinical benefits of hUC-MSCs on DFU healing were shown, including good tolerance, a shortened healing time to 1.5 months and a favorable 3-year amputation-free survival rate. The clinical evidence in the current study suggested a further phase I/II study with a larger patient population and a more rigorous design to explore the efficacy and mechanism of hUC-MSCs on DFU healing.

Trial registration: The current study was registered retrospectively on 22 Jan 2022 with the Chinese Clinical Trial Registry (ChiCTR2200055885), http://www.chictr.org.cn/showproj.aspx?proj=135888

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-03143-0.

Effectiveness and safety of stem cell therapy for diabetic foot: a meta-analysis update

BACKGROUND

Diabetic foot (DF) is one of the most common and serious complications of diabetes mellitus (DM), which brings great psychological and economic pressure to patients. This study aimed to evaluate the efficacy of stem cells in the treatment of diabetic foot.

METHODS

All relevant studies in Cochrane, Embase, PubMed, Web of Science, China National Knowledge Infrastructure, and WanFang databases were systematically searched for meta-analysis. The outcomes consisted of ulcer or wound healing rate, amputation rate, new vessels, ankle-brachial index (ABI), transcutaneous oxygen pressure (TcPO2), pain-free walking distance, and rest pain score. Dichotomous outcomes were described as risk ratios (RR) with 95% confidence intervals (CIs), while continuous data were presented as standardized mean differences (SMDs) with 95% CIs. Statistical analysis was performed with RevMan 5.3 software.

RESULTS

A total of 14 studies with 683 participants were included in the meta-analysis. Meta-analysis showed that stem cell therapy was more effective than conventional therapy in terms of ulcer or wound healing rate [OR = 8.20 (5.33, 12.62)], improvement in lower extremity ischemia(new vessels) [OR = 16.48 (2.88, 94.18)], ABI [MD = 0.13 (0.04, 0.08)], TcO2[MD = 4.23 (1.82, 6.65)], pain-free walking distance [MD = 220.79 (82.10, 359.48)], and rest pain score [MD = - 1.94 (- 2.50, - 1.39)], while the amputation rate was significantly decreased [OR = 0.19 (0.10, 0.36)].

CONCLUSIONS

The meta-analysis of the current studies has shown that stem cells are significantly more effective than traditional methods in the treatment of diabetic foot and can improve the quality of life of patients after treatment. Future studies should conduct large-scale, randomized, double-blind, placebo-controlled, multicenter trials with high-quality long-term follow-up to demonstrate the most effective cell types and therapeutic parameters for the treatment of diabetic foot.

The Immune-Centric Revolution in the Diabetic Foot: Monocytes and Lymphocytes Role in Wound Healing and Tissue Regeneration-A Narrative Review

Monocytes and lymphocytes play a key role in physiologic wound healing and might be involved in the impaired mechanisms observed in diabetes. Skin wound macrophages are represented by tissue resident macrophages and infiltrating peripheral blood recruited monocytes which play a leading role during the inflammatory phase of wound repair. The impaired transition of diabetic wound macrophages from pro-inflammatory M1 phenotypes to anti-inflammatory pro-regenerative M2 phenotypes might represent a key issue for impaired diabetic wound healing. This review will focus on the role of immune system cells in normal skin and diabetic wound repair. Furthermore, it will give an insight into therapy able to immuno-modulate wound healing processes toward to a regenerative anti-inflammatory fashion. Different approaches, such as cell therapy, exosome, and dermal substitute able to promote the M1 to M2 switch and able to positively influence healing processes in chronic wounds will be discussed.

Stem Cell Therapy for Diabetic Foot Ulcers: Theory and Practice

Diabetic foot ulcers are associated with increases in limb amputation, morbidity, and mortality. Recently, a stem cell application is emerging as promising adjuvant therapy. We presented available remedies by conducting a literature review on the application, safety, and efficacy of stem cell therapy. Relevant literature, including randomized control trials and article journals, was obtained from reputable search engines (PubMed, Scopus, and Web of Science). We analyzed five credible cohorts, with variable sources of stem cells, in a total of 216 participants, 151 males and 65 females, age (mean ± SD) of 64.5 ± 9.6 years. With an average success of 86.41% in all Wagner-II lesions, mesenchymal SCA (stem cell application) is safe and effective, hence can significantly prevent limb amputation.

Autologous Stem Cell Therapy for Chronic Lower Extremity Wounds: A Meta-Analysis of Randomized Controlled Trials

Lower extremity chronic wounds (LECWs) commonly occur in patients with diabetes mellitus (DM) and peripheral arterial disease (PAD). Autologous stem cell therapy (ASCT) has emerged as a promising alternative treatment for those who suffered from LECWs. The purpose of this study was to assess the effects of ASCT on LECWs. Two authors searched three core databases, and independently identified evidence according to predefined criteria. They also individually assessed the quality of the included randomized controlled trials (RCTs), and extracted data on complete healing rate, amputation rate, and outcomes regarding peripheral circulation. The extracted data were pooled using a random-effects model due to clinical heterogeneity among the included RCTs. A subgroup analysis was further performed according to etiology, source of stem cells, follow-up time, and cell markers. A total of 28 RCTs (n = 1096) were eligible for this study. The pooled results showed that patients receiving ASCT had significantly higher complete healing rates (risk ratio (RR) = 1.67, 95% confidence interval (CI) 1.28-2.19) as compared with those without ASCT. In the CD34+ subgroup, ASCT significantly led to a higher complete healing rate (RR = 2.70, 95% CI 1.50-4.86), but there was no significant difference in the CD34- subgroup. ASCT through intramuscular injection can significantly improve wound healing in patients with LECWs caused by either DM or critical limb ischemia. Lastly, CD34+ is an important cell marker for potential wound healing. However, more extensive scale and well-designed studies are necessary to explore the details of ASCT and chronic wound healing.

Intra-lesionally autologous stem cell application in diabetic foot/ulcer

The diabetic fot/ulcer is the cause of high morbidity and mortality in patients with diabetes mellitus (DM). Generally, medical treatment of diabetic foot/ulcer is ineffective and stem cell implantation is an important option in the treatment. Here, we present a 69 years old man admitted to hospital due to a 3 × 4 cm wound in the plantar surface of left foot. Autologous stem cells were applied intralesionally into diabetic ulcers. The lesion shrunken 50 % at the 16th week and there is a wound under the left foot at 32nd week. Intralesionally autologous stem cell application was useful and safe without adverse course in patients with diabetic foot/ulcer.

Health-related quality of life outcomes and Hospitalization length of stay after micro-fragmented autologous adipose tissue injection in minor amputations for diabetic foot ulceration (MiFrAADiF trial): results from a randomized controlled single-center clinical trial

BACKGROUND

The diabetic foot ulcer (DFU) is a high prevalence complication that significantly impairs the health-related quality of life (HRQoL) and is characterized by prolonged hospital length of stay (LOS). The impact of the micro-fragmented autologous adipose tissue injection at the minor amputation wound in the case of DFU (MiFrAADiF) on HRQoL and LOS compared to the standard care has not been determined yet.

METHODS

This was a two-arm, 6-month, individually randomized controlled single-center clinical trial. A 1:1 randomization to local injection of autologous micro-fragmented adipose tissue (treatment group; n=57) or standard clinical care (control group; n=57) was performed. The primary objective was the HRQoL. The secondary endpoint was the LOS. HRQoL was assessed with the Medical Outcomes Study 36-item Short-Form Health Survey which provides 2 scores focused on physical (PCS) and mental functioning (MCS). The trial was registered in ClinicalTrials.gov (NCT03276312).

RESULTS

The type of treatment (p=0.009) and the time elapsed since surgery (p= 0.0000) demonstrated a significant improvement on PCS. The MCS improvements resulted in a non-significant association with treatment (p= 0.21). The time elapsed since surgery showed a significant influence on the MCS (p= 0.0000). The mean LOS was 16.2 days and 24.4 days for the treatment and the control group respectively (p= 0.025).

CONCLUSIONS

The MiFrAADiF trial demonstrated a significant improvement in terms of physical HRQoL and a significant reduction of the hospital length of stay after injection of micro-fragmented autologous adipose tissue in diabetic patients' minor amputations wound.

Autologous cell therapy in diabetes‑associated critical limb ischemia: From basic studies to clinical outcomes (Review)

Cell therapy is becoming an attractive alternative for the treatment of patients with no‑option critical limb ischemia (CLI). The main benefits of cell therapy are the induction of therapeutic angiogenesis and neovascularization that lead to an increase in blood flow in the ischemic limb and tissue regeneration in non‑healing cutaneous trophic lesions. In the present review, the current state of the art of strategies in the cell therapy field are summarized, focusing on intra‑operative autologous cell concentrates in diabetic patients with CLI, examining different sources of cell concentrates and their mechanisms of action. The present study underlined the detrimental effects of the diabetic condition on different sources of autologous cells used in cell therapy, and also in delaying wound healing capacity. Moreover, relevant clinical trials and critical issues arising from cell therapy trials are discussed. Finally, the new concept of cell therapy as an adjuvant therapy to increase wound healing in revascularized diabetic patients is introduced.

Comprehensive Analysis of Cell Therapy on Chronic Skin Wound Healing: A Meta-Analysis

Wound healing has been greatly challenging in different acute and chronic skin injuries. Among them, nonrevascularizable critical limb ischemic ulcers, venous leg ulcers, and diabetic lower limb or extremity ulcers are well-known refractory skin injuries that are difficult to treat. Partly differentiated, progenitor cell-based graft transplantation or direct injection of autologous stem cells might promote the wound healing process. Studies aiming to comprehensively analyze the effects of cell therapy on skin wound healing could provide clinical evidence for skin injury treatment. Different databases were searched for full-text publications on the comparison between cell therapy and regular therapy. Heterogeneity was detected by the I² method, and a fixed effect model was applied for data pooling if heterogeneity was absent. Publication bias was analyzed using a funnel plot, and 10 studies were finally included in this study. After a long-term follow-up, fewer patients underwent major amputation in the cell therapy group, compared with the standard therapy group, and those in the cell therapy group were characterized by a smaller ulcer area. Moreover, there was a significant difference in the wound healing rate between the intervention and control groups. However, pain caused by skin wounds was hardly mitigated by cell therapy in patients with critical limb ischemia. In this study, cell therapy proved effective in decreasing the size of ulcers and improving the wound closure rate. Additionally, the major amputation rate was decreased in the cell therapy group. However, the symptoms of pain were hardly alleviated by cell therapy in patients with cutaneous ulcers caused by peripheral artery disease-related critical limb ischemia.

The Effect of Kiwifruit Therapeutics in the Treatment of Diabetic Foot Ulcer

Diabetes mellitus is considered a silent disease with possible late chronic complications such as diabetic foot ulcer. This condition is managed by surgical debridement. To improve surgical outcome, some surgeons use proteolytic agents after surgery. Kiwifruit contains a type of proteolytic enzyme called actinidin that may play a role in the treatment of such complication. In the current study, we evaluate the role of kiwifruit extract in the treatment of diabetic foot ulcer. Eighteen diabetic foot ulcer patients were included in a randomized, double-blind clinical trial. The patients were divided randomly to control and experimental groups. Patients in the control group underwent daily wound dressing using base ointment (Eucerin). In the experimental group, we added kiwifruit extract to the standard wound dressing. Clinical data including general appearance of wound (according to recorded photographs before and after medical intervention) were analyzed using SPSS version 22. The mean wound area of the experimental group was significantly less than in the control group (P = .005) after 4 weeks of treatment. Comparison of the average of size difference, before and after the treatment in the experimental group and the control group, shows that kiwifruit can have a good impact on wound healing (P = .0001). In patients with diabetic foot ulcer, wound dressing using kiwifruit extract may help reduce time of treatment and may replace surgical debridement for some selected cases.

Stem cell transplantation therapy for diabetic foot ulcer: a narrative review

Diabetes mellitus is a chronic metabolic disease associated with high cardiovascular risk. A vascular complication of diabetes is foot ulcers. Diabetic foot ulcers are prevalent and substantially reduce the quality of life of patients who have them. Currently, diabetic foot ulcer is a major problem for wound care specialists, and its treatment requires considerable health care resources. So far, various therapeutic modalities have been proposed to treat diabetic foot ulcers and one of them is stem cell-based therapy. Stem cell-based therapy has shown great promise for the treatment of diabetic foot ulcers. This strategy has been shown to be safe and effective in both preclinical and clinical trials. In this review, we provide an overview of the stem cell types and possible beneficial effects of stem cell transplantation therapy for diabetic foot ulcers, and an overview of the current status of stem cell research in both preclinical and clinical trial stages of treatment strategies for diabetic foot ulcers.

Autologous micro-fragmented adipose tissue for the treatment of diabetic foot minor amputations: a randomized controlled single-center clinical trial (MiFrAADiF)

Background

The diabetic foot ulcer (DFU) is one of the most prevalent complications of diabetes mellitus and often develops severe effects that can lead to amputation. A non-healing “minor” amputation often precedes a major amputation resulting in a negative impact on the function and quality of life of the patients. Stem cell-based therapies have emerged as a promising option to improve healing, and the adipose tissue is an abundant and easy to access source. The injection of autologous micro-fragmented adipose tissue at the amputation stump of a diabetic population undergoing a lower limb minor amputation was evaluated and compared with the standard care.

Methods

In this randomized controlled trial with two arms (parallel assignment) and no masking, 114 patients undergoing a lower limb minor amputation were randomized to standard of care or to micro-fragmented adipose tissue injection prepared using a minimal manipulation technique (Lipogems®) in a closed system. Clinical outcomes were determined monthly up to 6 months. Primary endpoint of the study was the evaluation of the healing rate and time after the minor amputation. Secondary endpoints included the assessment of safety, feasibility, technical success, relapse rate, skin tropism, and intensity of pain.

Results

At 6 months, 80% of the micro-fragmented adipose tissue-treated feet healed and 20% failed as compared with the control group where 46% healed and 54% failed (p = 0.0064). No treatment-related adverse events nor relapses were documented, and technical success was achieved in all cases. The skin tropism was improved in the treatment group, and the pain scale did not differ between the two groups.

Conclusion

The results of this randomized controlled trial suggest that the local injection of autologous micro-fragmented adipose tissue is a safe and valid therapeutic option able to improve healing rate following minor amputations of irreversible DFU. The technique overcomes several stem cell therapy-related criticisms and its potential in wound care should be better evaluated and the therapeutic indications could be expanded.

Trial registration

ClinicalTrials.gov number: NCT03276312. Date of registration: September 8, 2017 (retrospectively registered).

Skin tissue regeneration for burn injury

The skin is the largest organ of the body, which meets the environment most directly. Thus, the skin is vulnerable to various damages, particularly burn injury. Skin wound healing is a serious interaction between cell types, cytokines, mediators, the neurovascular system, and matrix remodeling. Tissue regeneration technology remarkably enhances skin repair via re-epidermalization, epidermal-stromal cell interactions, angiogenesis, and inhabitation of hypertrophic scars and keloids. The success rates of skin healing for burn injuries have significantly increased with the use of various skin substitutes. In this review, we discuss skin replacement with cells, growth factors, scaffolds, or cell-seeded scaffolds for skin tissue reconstruction and also compare the high efficacy and cost-effectiveness of each therapy. We describe the essentials, achievements, and challenges of cell-based therapy in reducing scar formation and improving burn injury treatment.

Diabetic endothelial colony forming cells have the potential for restoration with glycomimetics

Endothelial colony forming progenitor cell (ECFC) function is compromised in diabetes, leading to poor vascular endothelial repair, which contributes to impaired diabetic foot ulcer healing. We have generated novel glycomimetic drugs with protective effects against endothelial dysfunction. We investigated the effect of glycomimetic C3 on the functional capacity of diabetic ECFCs. ECFCs were isolated from healthy controls and patients with diabetes with neuroischaemic (NI) or neuropathic (NP) foot ulcers. Functionally, diabetic ECFCs demonstrated delayed colony formation (p < 0.02), differential proliferative capacity (p < 0.001) and reduced NO bioavailability (NI ECFCs; p < 0.05). Chemokinetic migration and angiogenesis were also reduced in diabetic ECFCs (p < 0.01 and p < 0.001), and defects in wound closure and tube formation were apparent in NP ECFCs (p < 0.01). Differential patterns in mitochondrial activity were pronounced, with raised activity in NI and depressed activity in NP cells (p < 0.05). The application of glycomimetic improved scratch wound closure in vitro in patient ECFCs (p < 0.01), most significantly in NI cells (p < 0.001), where tube formation (p < 0.05) was also improved. We demonstrate restoration of the deficits in NI cells but not NP cells, using a novel glycomimetic agent, which may be advantageous for therapeutic cell transplantation or as a localised treatment for NI but not NP patients.

Static Magnetic Field Accelerates Diabetic Wound Healing by Facilitating Resolution of Inflammation

Impaired wound healing is commonly encountered in patients with diabetes mellitus, which may lead to severe outcomes such as amputation, if untreated timely. Macrophage plays a critical role in the healing process including the resolution phase. Although magnetic therapy is known to improve microcirculation, its effect on wound healing remains uncertain. In the present study, we found that 0.6 T static magnetic field (SMF) significantly accelerated wound closure and elevated reepithelialization and revascularization in diabetic mice. Notably, SMF promoted the wound healing by skewing the macrophage polarization towards M2 phenotype, thus facilitating the resolution of inflammation. In addition, SMF upregulated anti-inflammatory gene expression via activating STAT6 and suppressing STAT1 in macrophage. Taken together, our results indicate that SMF may be a promising adjuvant therapeutic tool for treating diabetic wounds.