Mechanisms involved in the development and healing of diabetic foot ulceration

Combined analysis of single-cell sequencing and bulk transcriptome sequencing reveals new mechanisms for non-healing diabetic foot ulcers

Diabetic foot ulcers (DFUs) pose a significant challenge in diabetes care. Yet, a comprehensive understanding of the underlying biological disparities between healing and non-healing DFUs remains elusive. We conducted bioinformatics analysis of publicly available transcriptome sequencing data in an attempt to elucidate these differences. Our analysis encompassed differential analysis to unveil shifts in cell composition and gene expression profiles between non-healing and healing DFUs. Cell communication alterations were explored employing the Cellchat R package. Pseudotime analysis and cytoTRACE allowed us to dissect the heterogeneity within fibroblast subpopulations. Our findings unveiled disruptions in various cell types, localized low-grade inflammation, compromised systemic antigen processing and presentation, and extensive extracellular matrix signaling disarray in non-healing DFU patients. Some of these anomalies partially reverted in healing DFUs, particularly within the abnormal ECM-receptor signaling pathway. Furthermore, we distinguished distinct fibroblast subpopulations in non-healing and healing DFUs, each with unique biological functions. Healing-associated fibroblasts exhibited heightened extracellular matrix (ECM) remodeling and a robust wound healing response, while non-healing-associated fibroblasts showed signs of cellular senescence and complement activation, among other characteristics. This analysis offers profound insights into the wound healing microenvironment, identifies pivotal cell types for DFU healing promotion, and reveals potential therapeutic targets for DFU management.

A Single Center, Randomized Controlled Trial on the Efficacy of Topical Application of ReGenerating Tissue Agents (RGTA) Technology in Diabetic Foot Ulcers

Diabetic foot ulcers (DFUs) are a serious complication of diabetes mellitus. Clinical data from the use of ReGenerating Tissue Agents (RGTA) technology in patients with DFUs are scarce. The objective of this randomized controlled study was to evaluate the efficacy of RGTA technology in the management of DFUs. Patients with chronic, neuroischemic diabetic foot ulcers were randomized 1:1 to the control group, that received the standard of care, and to the intervention group, that additionally received RGTA twice per week. The duration of the intervention was 12 weeks. Skin biopsies for histological and immunohistochemical analyses from a sample of participants were also performed. About 31 patients completed the study. Five (31.2%) patients in the intervention group achieved complete healing at the end of the intervention period versus 0 patients in the control group (P = .043), [RR: 0.688 (95% CI: 0.494-0.957)]. The intervention group had more ulcers with at least 80% healing of their surface [10 (66.7%) versus 2 (13.3%), P = .008, RR: 0.385 (95% CI: 0.183-0.808)], higher absolute surface reduction [1.5 (0.7, 5.2) versus 0.6 (0.3, 1.0), P = .026] and higher percentages of surface reduction [94 (67, 100) versus 40 (26, 75), P = .001] at the end of the intervention period. More patients in the intervention group achieved at least 50% healing at the fourth week of the study [9 (64.3%) versus 2 (14.3%) P = .018, RR: 0.417 (95% CI: 0.200-0.869)]. Immunohistochemical analyses were performed in a sample of participants that revealed higher expression of CD163, COL3 and VEGFR in the intervention group. The adverse effects were similar between the 2 groups. The data from the present study suggest that the adjunction of RGTA technology in the management of diabetic foot ulcers is a safe practice that promotes wound healing.

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.

A double-network porous hydrogel based on high internal phase emulsions as a vehicle for potassium sucrose octasulfate delivery accelerates diabetic wound healing

Diabetic wounds are a difficult medical challenge. Excessive secretion of matrix metalloproteinase-9 (MMP-9) in diabetic wounds further degrades the extracellular matrix and growth factors and causes severe vascular damage, which seriously hinders diabetic wound healing. To solve these issues, a double-network porous hydrogel composed of poly (methyl methacrylate-co-acrylamide) (p(MMA-co-AM)) and polyvinyl alcohol (PVA) was constructed by the high internal phase emulsion (HIPE) technique for the delivery of potassium sucrose octasulfate (PSO), a drug that can inhibit MMPs, increase angiogenesis and improve microcirculation. The hydrogel possessed a typical polyHIPE hierarchical microstructure with interconnected porous morphologies, high porosity, high specific surface area, excellent mechanical properties and suitable swelling properties. Meanwhile, the p(MMA-co-AM)/PVA@PSO hydrogel showed high drug-loading performance and effective PSO release. In addition, both in vitro and in vivo studies showed that the p(MMA-co-AM)/PVA@PSO hydrogel had good biocompatibility and significantly accelerated diabetic wound healing by inhibiting excessive MMP-9 in diabetic wounds, increasing growth factor secretion, improving vascularization, increasing collagen deposition and promoting re-epithelialization. Therefore, this study provided a reliable therapeutic strategy for diabetic wound healing, some theoretical basis and new insights for the rational design and preparation of wound hydrogel dressings with high porosity, high drug-loading performance and excellent mechanical properties.

Use of Serum Protein Measurements as Biomarkers that Can Predict the Outcome of Diabetic Foot Ulceration

Objectives: To identify proteins that are prognostic for diabetic foot ulcer (DFU) healing and may serve as biomarkers for its management, serum samples were analyzed from diabetic mellitus (DM) patients. Approach: The serum specimens that were evaluated in this study were obtained from DM patients with DFU who participated in a prospective study and were seen biweekly until they healed their ulcer or the exit visit at 12 weeks. The group was divided into Healers (who healed their DFU during the study) and Non-Healers. Results: Interleukin (IL)-10, IL-4, IL-5, IL-6, and IL-13 and interferon-gamma were higher in the Healers while Fractalkine, IL-8, and TNFα were higher in the Non-Healers. The trajectory of IL-10 levels remained stable over time within and across groups, resulting in a strong prognostic ability for the prospective DFU healing course. Classification and Regression Tree analysis created an 11-node decision tree with healing status as the categorical response. Innovation: Consecutive measurements of proteins associated with wound healing can identify biomarkers that can predict DFU healing over a 12-week period. IL-10 was the strongest candidate for prediction. Conclusion: Measurement of serum proteins can serve as a successful strategy in guiding clinical management of DFU. The data also indicate likely superior performance of building a multiprotein biomarker score instead of relying on single biomarkers.

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.

Recombinantly expressed rhFEB remodeled the skin defect of db/db mice

Fibronectin (FN) and collagen are vital components of the extracellular matrix (ECM). These proteins are essential for tissue formation and cell alignment during the wound healing stage. In particular, FN interacts with collagens to activate various intracellular signaling pathways to maintain ECM stability. A novel recombinant extra domain-B fibronectin (EDB-FN)-COL3A1 fusion protein (rhFEB) was designed to mimic the ECM to promote chronic and refractory skin ulcer wound healing. rhFEB significantly enhanced cell adhesion and migration, vascular ring formation, and the production of new collagen I (COL1A1) in vitro. rhFEB decreased M1 macrophages and further modulated the wound microenvironment, which was confirmed by the treatment of db/db mice with rhFEB. Accelerated wound healing was shown during the initial stages in rhFEB-treated db/db mice, as was enhanced follicle regeneration, re-epithelialization, collagen deposition, granulation, inflammation, and angiogenesis. The wound chronicity of diabetic foot ulcers (DFUs) remains the main challenge in current and future treatment. rhFEB may be a candidate molecule for regulating M1 macrophages during DFU healing. KEY POINTS: • A recombinant protein EDB-FN-collagen III (rhFEB) was highly expressed in Escherichia coli • rhFEB protein induces COL1A1 secretion in human skin fibroblasts • rhFEB protein accelerates diabetic wound healing.

Based on Clinical Research Matrix Metalloprotease (MMP) Inhibitors to Promote Diabetic Wound Healing

Chronic inflammation is a common factor in obesity, diabetes mellitus, and the complications of diabetes, including diabetic wounds. These ulcers are characterized by persistent lesions that are challenging to heal, significantly decreasing patients' quality of life and imposing a substantial financial burden on society. MMP are zinc endopeptidases that play a role in wound healing in response to various stimuli, including diabetes mellitus. MMP levels fluctuate throughout the wound healing process in diabetic patients' serum, skin tissues, and wound fluid, indicating their potential as biomarkers for diabetic foot ulcers. Targeting MMP has emerged as a promising strategy for treating diabetic wounds, as these enzymes are involved in critical biological processes related to wound healing, including extracellular matrix secretion, angiogenesis, granulation tissue formation, collagen growth, re-epithelization, inflammatory response, and oxidative stress.

Tailored biomedical materials for wound healing

Wound healing is a long-term, multi-stage biological process that mainly includes haemostatic, inflammatory, proliferative and tissue remodelling phases. Controlling infection and inflammation and promoting tissue regeneration can contribute well to wound healing. Smart biomaterials offer significant advantages in wound healing because of their ability to control wound healing in time and space. Understanding how biomaterials are designed for different stages of wound healing will facilitate future personalized material tailoring for different wounds, making them beneficial for wound therapy. This review summarizes the design approaches of biomaterials in the field of anti-inflammatory, antimicrobial and tissue regeneration, highlights the advanced precise control achieved by biomaterials in different stages of wound healing and outlines the clinical and practical applications of biomaterials in wound healing.

Upregulation of circ_0080968 in diabetic foot ulcer inhibits wound healing via repressing the migration and promoting proliferation of keratinocytes

BACKGROUND

Diabetic foot ulcer (DFU) is a serious chronic complication of diabetes mellitus whose pathogenesis remains unclear. Circular RNA (circRNA) refers to a group of covalently closed non-coding RNAs that are reported to be dysregulated in patients with DFU. However, the mechanism whereby dysregulation in circRNAs contributes to DFU remains unclear. In this study, we investigated the role of dysregulated circRNAs in DFU.

MATERIALS AND METHODS

A gene expression dataset was downloaded from the Gene Expression Omnibus portal and analyzed by the limma package of R. The levels of 24 upregulated circRNAs were detected in two independent cohorts by RT-qPCR. Interactions between miRNAs and circRNAs were predicted through bioinformatics and confirmed using a dual luciferase assay. The circularity and subcellular localization of circRNA-080968 was examined by northern blotting after digestion with RNase-R and in situ hybridization. Cell migration and proliferation were examined using Transwell and MTT assays. The apoptotic cells were detected by flow cytometry.

RESULTS

The level of circRNA-080968 was upregulated in DFU tissues compared to that of non-DFU samples and normal human wounds. CircRNA-080968 was mainly localized in the cytoplasm and its overexpression inhibited the migration and promoted the proliferation of keratinocytes. MiR-326 and miR-766-3p were identified to interact with and be negatively correlated with circRNA-080968 levels. Increased glucose upregulated circRNA-080968, and its overexpression accelerated the degradation of both miR-326 and miR-766-3p. Reduced levels of miR-326 and miR-766-3p upregulated the expression of several genes controlling cell adhesion and proliferation which are related to the pathogenesis of DFU.

CONCLUSIONS

The upregulation of circRNA-080968 in DFU induced the degradation of miR-326 and miR-766-3p, which further repressed the migration and increased the proliferation of keratinocytes.

Gram-Negative Bacteria and Lipopolysaccharides as Risk Factors for the Occurrence of Diabetic Foot

CONTEXT

Imbalance of the skin microbial community could impair skin immune homeostasis and thus trigger skin lesions. Dysbiosis of skin microbiome may be involved in the early pathogenesis of diabetic foot (DF). However, the potential mechanism remains unclear.

OBJECTIVE

To investigate the dynamic composition and function of the foot skin microbiome with risk stratification for DF and assess whether dysbiosis of the skin microbiome induces diabetic skin lesions.

METHODS

We enrolled 90 consecutive subjects who were divided into 5 groups based on DF risk stratification: very low, low, moderate, and high risk for ulcers and a healthy control group. Integrated analysis of 16S ribosomal RNA and metagenomic sequencing of cotton swab samples was applied to identify the foot skin microbiome composition and functions in subjects. Then a mouse model of microbiota transplantation was used to evaluate the effects of the skin microbiome on diabetic skin lesions.

RESULTS

The results demonstrated that, with the progression of diabetic complications, the proportion of gram-negative bacteria in plantar skin increased. At the species level, metagenome sequencing analyses showed Moraxella osloensis to be a representative core strain in the high-risk group. The major microbial metabolites affecting diabetic skin lesions were increased amino acid metabolites, and antibiotic resistance genes in microorganisms were abundant. Skin microbiota from high-risk patients induced more inflammatory cell infiltration, similar to the lipopolysaccharide (LPS)-stimulated response, which was inhibited by Toll-like receptor 4 (TLR4) antagonists.

CONCLUSIONS

The skin microbiome in patients with diabetes undergoes dynamic changes at taxonomic and functional levels with the progression of diabetic complications. The increase in gram-negative bacteria on the skin surface through LPS-TLR4 signal transduction could induce inflammatory response in early diabetic skin lesions.

Topically-applied collagen-binding serum albumin-fused interleukin-4 modulates wound microenvironment in non-healing wounds

Non-healing wounds have a negative impact on quality of life and account for many cases of amputation and even early death among patients. Diabetic patients are the predominate population affected by these non-healing wounds. Despite the significant clinical demand, treatment with biologics has not broadly impacted clinical care. Interleukin-4 (IL-4) is a potent modulator of the immune system, capable of skewing macrophages towards a pro-regeneration phenotype (M2) and promoting angiogenesis, but can be toxic after frequent administration and is limited by its short half-life and low bioavailability. Here, we demonstrate the design and characterization of an engineered recombinant interleukin-4 construct. We utilize this collagen-binding, serum albumin-fused IL-4 variant (CBD-SA-IL-4) delivered in a hyaluronic acid (HA)-based gel for localized application of IL-4 to dermal wounds in a type 2 diabetic mouse model known for poor healing as proof-of-concept for improved tissue repair. Our studies indicate that CBD-SA-IL-4 is retained within the wound and can modulate the wound microenvironment through induction of M2 macrophages and angiogenesis. CBD-SA-IL-4 treatment significantly accelerated wound healing compared to native IL-4 and HA vehicle treatment without inducing systemic side effects. This CBD-SA-IL-4 construct can address the underlying immune dysfunction present in the non-healing wound, leading to more effective tissue healing in the clinic.

Annexin A12-26 hydrogel improves healing properties in an experimental skin lesion after induction of type 1 diabetes

Diabetes mellitus (DM) is characterized by metabolic alterations that involve defects in the secretion and/or action of insulin, being responsible for several complications, such as impaired healing. Studies from our research group have shown that annexin A1 protein (AnxA1) is involved in the regulation of inflammation and cell proliferation. In light of these findings, we have developed a new technology and evaluated its effect on a wound healing in vivo model using type 1 diabetes (T1DM)-induced mice. We formulated a hydrogel containing AnxA12-26 using defined parameters such as organoleptic characteristics, pH, UV-vis spectroscopy and cytotoxicity assay. UV-vis spectroscopy confirmed the presence of the associated AnxA12-26 peptide in the three-dimensional hydrogel matrix, while the in vitro cytotoxicity assay showed excellent biocompatibility. Mice showed increased blood glucose levels, confirming the efficacy of streptozotocin (STZ) to induce T1DM. Treatment with AnxA12-26 hydrogel showed to improve diabetic wound healing, defined as complete re-epithelialization and tissue remodeling, with reduction of inflammatory infiltrate in diabetic animals. We envisage that the AnxA12-26 hydrogel, with its innovative composition and formulation be efficient on improving diabetic healing and contributing on the expansion of the therapeutic arsenal to treat diabetic wounds, at a viable cost.

Research advances in smart responsive-hydrogel dressings with potential clinical diabetic wound healing properties

The treatment of chronic and non-healing wounds in diabetic patients remains a major medical problem. Recent reports have shown that hydrogel wound dressings might be an effective strategy for treating diabetic wounds due to their excellent hydrophilicity, good drug-loading ability and sustained drug release properties. As a typical example, hyaluronic acid dressing (Healoderm) has been demonstrated in clinical trials to improve wound-healing efficiency and healing rates for diabetic foot ulcers. However, the drug release and degradation behavior of clinically-used hydrogel wound dressings cannot be adjusted according to the wound microenvironment. Due to the intricacy of diabetic wounds, antibiotics and other medications are frequently combined with hydrogel dressings in clinical practice, although these medications are easily hindered by the hostile environment. In this case, scientists have created responsive-hydrogel dressings based on the microenvironment features of diabetic wounds (such as high glucose and low pH) or combined with external stimuli (such as light or magnetic field) to achieve controllable drug release, gel degradation, and microenvironment improvements in order to overcome these clinical issues. These responsive-hydrogel dressings are anticipated to play a significant role in diabetic therapeutic wound dressings. Here, we review recent advances on responsive-hydrogel dressings towards diabetic wound healing, with focus on hydrogel structure design, the principle of responsiveness, and the behavior of degradation. Last but not least, the advantages and limitations of these responsive-hydrogels in clinical applications will also be discussed. We hope that this review will contribute to furthering progress on hydrogels as an improved dressing for diabetic wound healing and practical clinical application.

Assessment framework for the selection of a potential interactive dressing material for diabetic foot ulcer

Diabetic foot ulcer is a chronic health issue leading to lower leg amputations in approximately 15% of patients with diabetics. There are many factors directly or indirectly involved in the physiology of wound healing but being a multisystem disorder, wound healing in diabetic patients retard or worsen with heavy exudates and severe microbial infections. Wound management is of prime importance and is an emerging area to incorporate wound regenerative materials in natural or synthetic dressing materials along with proper microbial control. The article aim to identify suitable dressing materials which exhibit inherent wound healing properties at the same time flexible to be used as drug carriers for slow, consistent and effective delivery of 'functional drugs' to the wound environment. The authors selected nine materials from the popular and well accepted dressings of patient choice, analyzed them using graph theoretic approach and ranked them on the basis of graph index values obtained. A critical review has also been done on the basis of their ranking, providing insights to the advantages, disadvantage and potential of top 5 ranked candidate materials. Alginate, Honey, Medifoam, Saline, and Hydrogel dressings were the top five candidate materials ranked respectively, even then, the authors suggests that 'modified hydrogels' can have the potential to be used as a future candidate in DFU treatment as it is the only material (among the top ranked ones) which can effectively used as regenerative drug carrier, while providing all other wound healing properties in relative proportions. The proposed framework can be modified and applied in the selection and ranking of materials for any kind of applications both in industry and medical fields by identifying factors influencing the final outcome of study and by listing the characteristics of the materials selected.

Cholesterol Levels and Monocyte Phenotype Are Predictors of Nonhealing in Individuals with Low-Grade Diabetic Foot Ulcers: A Prospective Cohort Study

Objective: Inflammation has been linked to progression of diabetic foot ulcers (DFU); however, specific predictive markers of nonhealing are scarce. The goal of this study was to identify biochemical and immunological parameters from the blood as predictors of nonhealing in grade 1 and grade 2 DFU. Approach: Individuals with low-grade foot ulcers were enrolled in the study to determine if histopathological, biochemical, and immunological parameters could be used to predict individuals whose ulcers would not heal. Data analysis was performed using traditional univariate analyses as well as univariate and multivariable logistic regression, and STROBE guidelines were used for reporting data. Results: Among the 52 individuals who completed the study, we observe that no single histopathological and biochemical parameter was predictive. Conventional univariate analysis and univariate logistic regression analysis showed that the expression of the cell surface proteins CD63, HLA-DR, and CD11b on monocytes was significantly lower in nonhealed individuals, but with moderate discriminative ability. In comparison, a multivariable logistic regression model identified four of the 31 parameters to be salient predictors with low density lipoprotein (LDL) cholesterol (odds ratio [OR] 18.83, confidence interval [CI] 18.83-342) and cell-surface expression of CD63 on monocytes (OR 0.12, CI 0.12-0.45) showing significance and demonstrating high discrimination ability. Innovation: The approach of using a combination of biochemical and immunological parameters to predict ulcer healing is new. Conclusion: Through this study we conclude that LDL cholesterol and cell-surface expression of CD63 on monocytes strongly correlate with nonhealing in individuals with grade 1 and grade 2 DFU.

New Approaches in Heart Research: Prevention Instead of Cardiomyoplasty?

Cardiovascular diseases are the leading cause of death in industrialized nations. Due to the high number of patients and expensive treatments, according to the Federal Statistical Office (2017) in Germany, cardiovascular diseases account for around 15% of total health costs. Advanced coronary artery disease is mainly the result of chronic disorders such as high blood pressure, diabetes, and dyslipidemia. In the modern obesogenic environment, many people are at greater risk of being overweight or obese. The hemodynamic load on the heart is influenced by extreme obesity, which often leads to myocardial infarction (MI), cardiac arrhythmias, and heart failure. In addition, obesity leads to a chronic inflammatory state and negatively affects the wound-healing process. It has been known for many years that lifestyle interventions such as exercise, healthy nutrition, and smoking cessation drastically reduce cardiovascular risk and have a preventive effect against disorders in the healing process. However, little is known about the underlying mechanisms, and there is significantly less high-quality evidence compared to pharmacological intervention studies. Due to the immense potential of prevention in heart research, the cardiologic societies are calling for research work to be intensified, from basic understanding to clinical application. The topicality and high relevance of this research area are also evident from the fact that in March 2018, a one-week conference on this topic with contributions from top international scientists took place as part of the renowned "Keystone Symposia" ("New Insights into the Biology of Exercise"). Consistent with the link between obesity, exercise, and cardiovascular disease, this review attempts to draw lessons from stem-cell transplantation and preventive exercise. The application of state-of-the-art techniques for transcriptome analysis has opened new avenues for tailoring targeted interventions to very individual risk factors.

Effectiveness of Topical Sucralfate in the Management of Diabetic Foot Ulcers: An Open-Labeled Randomized Study

INTRODUCTION

Diabetic foot ulcer (DFU) is a major cause of lower limb amputations. Many treatment recommendations have been proposed. This study was conducted to evaluate the effectiveness of topical sucralfate when combined with mupirocin ointment, in the treatment of diabetic foot ulcer in comparison to topical mupirocin alone, in terms of healing rates.

METHODS

This open-labeled randomized study was conducted on 108 patients to evaluate the effectiveness of topical sucralfate and mupirocin combination, compared to topical mupirocin alone. The patients were administered the same parenteral antibiotic, and wounds were subjected to daily dressing. The healing rates (determined by the percentage reduction in wound area) in the two groups were calculated. The mean healing rates in both groups were expressed in percentage and compared using the Student's t-test.

RESULTS

A total of 108 patients were included in the study. Male-to-female ratio was 3:1. The incidence of diabetic foot was the highest (50.9%) in the age group of 50-59 years. The mean age of the study population was 51 years. The incidence of diabetic foot ulcers was highest in the months of July-August (42%). A total of 71.2% patients had random blood sugar levels between 150-200 mg/dL, and 72.2% patients had diabetes for five to 10 years. The mean±standard deviation (SD) of the healing rates in the sucralfate and mupirocin combination group and the control group were 16.2±7.3% and 14.5±6.6%, respectively. Comparison of the means by Student's t-test failed to show a statistical difference in healing rates between the two groups (p=0.201).

CONCLUSION

We concluded that the addition of topical sucralfate does not show any obvious benefits in terms of healing rates in diabetic foot ulcers as compared to mupirocin alone.

The Association of Inflammatory Factors With Peripheral Neuropathy: The Study of Women's Health Across the Nation

PURPOSE

Previous work has focused on the role of diabetes in peripheral neuropathy (PN), but PN often occurs before, and independently from, diabetes. This study measures the association of cardiometabolic and inflammatory factor with PN, independent of diabetes.

METHODS

Study of Women's Health Across the Nation participants (n = 1910), ages 60 to 73 (mean 65.6) were assessed for PN by symptom questionnaire and monofilament testing at the 15th follow-up visit (V15). Anthropometric measures and biomarkers were measured at study baseline approximately 20 years prior, and C-reactive protein (CRP) and fibrinogen were measured longitudinally. Log-binomial regression was used to model the association between metabolic syndrome (MetS), obesity (≥35 body mass index), CRP, and fibrinogen with PN, adjusting for sociodemographic and health behavior measures.

RESULTS

Baseline MetS [prevalence ratio (PR) 1.79, 95% CI (1.45, 2.20)], obesity [PR 2.08 (1.65, 2.61)], median CRP [PR 1.32 per log(mg/dL), (1.20, 1.45)], and mean fibrinogen (PR 1.28 per 100 mg/dL, (1.09, 1.50)] were associated with PN symptoms at V15. After excluding participants with baseline diabetes or obesity, MetS [PR 1.59 (1.17, 2.14)] and CRP [PR 1.19 per log(mg/dL), (1.06, 1.35)] remained statistically significantly associated with PN. There was a negative interaction between MetS and obesity, and the association between these conditions and PN was mediated by CRP.

CONCLUSIONS

Cardiometabolic factors and inflammation are significantly associated with PN, independent of diabetes and obesity. CRP mediates the relationship of both obesity and MetS with PN, suggesting an etiological role of inflammation in PN in this sample.

Sex difference on fibroblast growth factors (FGFs) expression in skin and wound of streptozotocin(STZ)-induced type 1 diabetic mice

BACKGROUND

Fibroblast growth factors (FGFs) are key factors affecting diabetic wound healing. However, the FGF family's expression patterns in skin and wounds influenced by both diabetes and sex are still unknown.

METHODS AND RESULTS

In this study, normal and Streptozotocin (STZ)-induced type 1 diabetic C57BL/6J male and female mice were used to study the FGF family's expression in non-wound skin and wounds. We found that the expression patterns of Fgfs were affected by sex in both normal and diabetic animals during wound healing. In normal control mice, sex difference had a limited effect on basal skin Fgf expressions. However, it significantly influenced Fgf expressions in wounds. Type 1 diabetes reduced basal and wound-induced skin Fgf expressions. Female mice had far lower wound-induced skin Fgf expressions in diabetic mice. In addition, sex differently influenced Fibroblast growth factors receptor (Fgfr) expression patterns of non-wound skin and wounds in both normal and diabetic mice. Moreover, female mice had a lower relative level of Fibronectin leucine-rich repeat transmembrane protein 2 (FLRT2) - a FGFR activation marker gene - in wound and blood plasma. Correspondingly, the wound areas of female animals were larger than that of male animals in the early stage of wound healing (less than 3-day injury).

CONCLUSION

Our research shows that the FGF family have different expression patterns in normal and diabetic wound healing in mice of different sex. Additionally, we also provide the signatures of individual FGFs in diabetic wound healing, which deserve further investigation.

Novel Biotherapeutics Targeting Biomolecular and Cellular Approaches in Diabetic Wound Healing

Wound healing responses play a major role in chronic inflammation, which affects millions of people around the world. One of the daunting tasks of creating a wound-healing drug is finding equilibrium in the inflammatory cascade. In this study, the molecular and cellular mechanisms to regulate wound healing are explained, and recent research is addressed that demonstrates the molecular and cellular events during diabetic wound healing. Moreover, a range of factors or agents that facilitate wound healing have also been investigated as possible targets for successful treatment. It also summarises the various advances in research findings that have revealed promising molecular targets in the fields of therapy and diagnosis of cellular physiology and pathology of wound healing, such as neuropeptides, substance P, T cell immune response cDNA 7, miRNA, and treprostinil growth factors such as fibroblast growth factor, including thymosin beta 4, and immunomodulators as major therapeutic targets.

Targeting matrix metalloproteases in diabetic wound healing

Chronic inflammation participates in the progression of multiple chronic diseases, including obesity, diabetes mellitus (DM), and DM related complications. Diabetic ulcer, characterized by chronic wounds that are recalcitrant to healing, is a serious complication of DM tremendously affecting the quality of life of patients and imposing a costly medical burden on society. Matrix metalloproteases (MMPs) are a family of zinc endopeptidases with the capacity of degrading all the components of the extracellular matrix, which play a pivotal part in healing process under various conditions including DM. During diabetic wound healing, the dynamic changes of MMPs in the serum, skin tissues, and wound fluid of patients are in connection with the degree of wound recovery, suggesting that MMPs can function as essential biomarkers for the diagnosis of diabetic ulcer. MMPs participate in various biological processes relevant to diabetic ulcer, such as ECM secretion, granulation tissue configuration, angiogenesis, collagen growth, re-epithelization, inflammatory response, as well as oxidative stress, thus, seeking and developing agents targeting MMPs has emerged as a potential way to treat diabetic ulcer. Natural products especially flavonoids, polysaccharides, alkaloids, polypeptides, and estrogens extracted from herbs, vegetables, as well as animals that have been extensively illustrated to treat diabetic ulcer through targeting MMPs-mediated signaling pathways, are discussed in this review and may contribute to the development of functional foods or drug candidates for diabetic ulcer therapy. This review highlights the regulation of MMPs in diabetic wound healing, and the potential therapeutic ability of natural products for diabetic wound healing by targeting MMPs.

Current and future outlook of loaded components in hydrogel composites for the treatment of chronic diabetic ulcers

Due to recalcitrant microangiopathy and chronic infection, traditional treatments do not easily produce satisfactory results for chronic diabetic ulcers. In recent years, due to the advantages of high biocompatibility and modifiability, an increasing number of hydrogel materials have been applied to the treatment of chronic wounds in diabetic patients. Research on composite hydrogels has received increasing attention since loading different components can greatly increase the ability of composite hydrogels to treat chronic diabetic wounds. This review summarizes and details a variety of newly loaded components currently used in hydrogel composites for the treatment of chronic diabetic ulcers, such as polymer/polysaccharides/organic chemicals, stem cells/exosomes/progenitor cells, chelating agents/metal ions, plant extracts, proteins (cytokines/peptides/enzymes) and nucleoside products, and medicines/drugs, to help researchers understand the characteristics of these components in the treatment of diabetic chronic wounds. This review also discusses a number of components that have not yet been applied but have the potential to be loaded into hydrogels, all of which play roles in the biomedical field and may become important loading components in the future. This review provides a "loading component shelf" for researchers of composite hydrogels and a theoretical basis for the future construction of "all-in-one" hydrogels.

Effect of matrix metalloproteinases on the healing of diabetic foot ulcer: A systematic review

BACKGROUND

This study aims to discuss the expression of matrix metalloproteinase in wound healing of diabetic foot ulcers and further summarize the strategies of targeted matrix metalloproteinase and its inhibitors in the treatment of diabetic foot ulcers.

METHODS

Following PRISMA-SCR guidelines, databases (PubMed, Home-PMC-NCBI, CINAHL, Web of Science) were systematically searched from inception to 19 June 2022. Newcastle-Ottawa Scale (NOS) was used to evaluate the bias risk of the included studies.

RESULTS

Eight studies are finally eligible for our systematic review. The combined data analysis of 8 studies showed that there were no significant difference in age(p = 0.110), duration of diabetes(p = 0.197), glycosylated hemoglobin content(p = 0.489), size(p = 0.133) and depth(p＞0.05) of initial ulcer between the ulcer wound healing group and the non-healing group. MMP-1, 2, 8, 9, and TIMP-1, 2 affected the healing of DFUs. In the DFUs healing group, the concentrations of MMP (MMP-1, 2, 8, 9) decreased, and the concentration of TIMP-1 increased.

CONCLUSION

Our study showed that high levels of MMP-1, 2, 9 delayed the healing of diabetic foot ulcers, and high expression of MMP-8 in tissues improved wound healing. This study also summarized the effective intervention strategies for the treatment of diabetic foot ulcers.

Effects of Intensive Glycemic Control on Serum Exosome miR-126-3p and miR-125b-1-3p Levels and Wound Healing in Patients with Diabetic Ulcers

Objective

Intensive glycemic control and exosomal miRNAs have both been reported to improve wound repair in diabetic ulcers. In this study, we aimed to investigate the effects of intensive glycemic control on serum exosome microRNA-126-3p (miR-126-3p), microRNA-125b-1-3p (miR-125b-1-3p), and wound healing in patients with diabetic ulcers.

Methods

Herein, 45 diabetic patients with an ulcer, aged 35-75 years old, were randomly assigned to the intensive glycemic control group (n = 21) and the conventional glycemic control group (n = 24). Serum exosomes were extracted in the laboratory and assessed by Western blotting, transmission electron microscopy, and nanoparticle tracking analysis. The expression of miR-126-3p and miR-125b-1-3p was validated using quantitative real-time polymerase chain reaction. The wound healing of each diabetic ulcer patient was measured and imaged; additionally, clinical and follow-up data were collected. Finally, the clinical and laboratory data were combined for statistical analysis.

Results

Intensive glycemic control was significantly more conducive to wound healing and infection control than conventional glycemic control (P < 0.05). Serum exosomal miR-126-3p was negatively correlated with fasting plasma glucose levels (r = 0.34, P < 0.05) and positively associated with the wound healing rate (r = 0.45, P < 0.01). The level of miR-126-3p in the intensive glycemic control group was significantly higher than that in the conventional glycemic control group (P < 0.01). Serum exosomal miR-125b-1-3p was not correlated with blood glucose levels (r = 0.03, P > 0.05) and was positively associated with the wound healing rate (r = 0.33, P < 0.05). No significant difference was observed in the level of miR-125b-1-3p between the intensive and conventional glycemic control groups. Regarding the prognosis of diabetic ulcers, the intensive glycemic control group was better than the conventional group (Z = -2.02, P < 0.05).

Conclusion

Serum exosome (miR-125b-1-3p and miR-126-3p) levels are correlated with wound healing in diabetic ulcers. Intensive glycemic control increases the serum exosomal miR-126-3p level, which might be one of the mechanisms that promotes wound healing in diabetic ulcers.

Pterostilbene attenuates hemin-induced dysregulation of macrophage M2 polarization via Nrf2 activation in experimental hyperglycemia

Macrophages exhibit a high degree of plasticity that is physiologically relevant in wound healing, and disruption in normal macrophage response leads to delayed wound closure resulting in chronic wounds. Here, we attempt to discern macrophage responses to hemin via regulation of the nuclear factor-erythroid factor 2-related factor 2 (Nrf2) that could help us better understand the pathophysiology of diabetic foot ulcers (DFU). We demonstrate the alleviation of hemin-mediated Nrf2 suppression and M2 macrophage polarization by pterostilbene (PTS), a proven Nrf2 activator. IC-21 macrophages were treated with hemin under the normoglycemic or hyperglycemic environment with or without PTS and the expression levels of various markers, such as Nrf2 and its downstream target Heme Oxygenase-1 (HO-1), CD206, Ferroportin-1 among others were analyzed using qPCR and Western blot. Our results revealed that hemin under hyperglycemia reduced Nrf2 activation and its downstream targets, M2 polarization, and the induction of a proinflammatory cellular environment, and interestingly all of these were remedied by PTS treatment. Gelatin zymography of matrix metalloproteinase2 (MMP2) expression revealed that hemin under hyperglycemic condition significantly elevated MMP2 expression, which was reversed by PTS treatment. Further proteomic analysis using liquid chromatography with tandem mass spectrometry (LC-MS/MS) revealed a heightened cellular stress profile accompanying inflammation that was suppressed by PTS. This study has furthered our understanding on the role of Nrf2 in attenuating hemin-induced perturbations in macrophage responses and suggests a potential therapeutic target in the management of DFU.

The neuropeptide substance P/neurokinin-1 receptor system and diabetes: From mechanism to therapy

Diabetes is a significant public health issue known as the world's fastest-growing disease condition. It is characterized by persistent hyperglycemia and subsequent chronic complications leading to organ dysfunction and, ultimately, the failure of target organs. Substance P (SP) is an undecapeptide that belongs to the family of tachykinin (TK) peptides. The SP-mediated activation of the neurokinin 1 receptor (NK1R) regulates many pathophysiological processes in the body. There is also a relation between the SP/NK1R system and diabetic processes. Importantly, deregulated expression of SP has been reported in diabetes and diabetes-associated chronic complications. SP can induce both diabetogenic and antidiabetogenic effects and thus affect the pathology of diabetes destructively or protectively. Here, we review the current knowledge of the functional relevance of the SP/NK1R system in diabetes pathogenesis and its exploitation for diabetes therapy. A comprehensive understanding of the role of the SP/NK1R system in diabetes is expected to shed further light on developing new therapeutic possibilities for diabetes and its associated chronic conditions.

Mapping intellectual structure and research hotspots in the field of fibroblast-associated DFUs: a bibliometric analysis

Background

Diabetic foot ulcers (DFUs) are one of the most popular and severe complications of diabetes. The persistent non-healing of DFUs may eventually contribute to severe complications such as amputation, which presents patients with significant physical and psychological challenges. Fibroblasts are critical cells in wound healing and perform essential roles in all phases of wound healing. In diabetic foot patients, the disruption of fibroblast function exacerbates the non-healing of the wound. This study aimed to summarize the hotspots and evaluate the global research trends on fibroblast-related DFUs through bibliometric analysis.

Methods

Scientific publications on the study of fibroblast-related DFUs from January 1, 2000 to April 27, 2022 were retrieved from the Web of Science Core Collection (WoSCC). Biblioshiny software was primarily performed for the visual analysis of the literature, CiteSpace software and VOSviewer software were used to validate the results.

Results

A total of 479 articles on fibroblast-related DFUs were retrieved. The most published countries, institutions, journals, and authors in this field were the USA, The Chinese University of Hong Kong, Wound Repair and Regeneration, and Seung-Kyu Han. In addition, keyword co-occurrence networks, historical direct citation networks, thematic map, and the trend topics map summarize the research hotspots and trends in this field.

Conclusion

Current studies indicated that research on fibroblast-related DFUs is attracting increasing concern and have clinical implications. The cellular and molecular mechanisms of the DFU pathophysiological process, the molecular mechanisms and therapeutic targets associated with DFUs angiogenesis, and the measures to promote DFUs wound healing are three worthy research hotspots in this field.

Intragastric administration of Pien Tze Huang enhanced wound healing in diabetes by inhibiting inflammation and improving energy generation

BACKGROUND AND PURPOSE

As a complex and challenging complication for the patients with diabetes mellitus, diabetic ulcers are difficult to heal and current strategies cannot fulfill the patients' requirements. Pien Tze Huang (PZH) is a standardized medicine approved for various wounds treatments, and this study systematically investigated the effect and mechanism of intragastric administration of PZH (I-PZH) on diabetic wound healing.

METHODS AND RESULTS

The effect of I-PZH on the healing of full-thickness wounds in rats with diabetes mellitus which was induced by high fat diet followed by streptozotocin injection was evaluated, and RNA sequencing (RNA-seq) and targeted central carbon metabolism metabolomics were combined to explore the underlying mechanism. I-PZH promoted wound healing, facilitated extracellular matrix synthesis, and maintained body weight of rats, but did not affect fasting blood glucose levels. Additionally, I-PZH significantly decreased 8-OHdG, cleaved caspase 3 and MMP9 levels, and increased TGF-β1 expression. RNA-seq analysis showed that I-PZH inhibited inflammation and that the vital common targets were TLR2, IL-17A and IL-1β; specifically affected "energy derivation by oxidation of organic compounds" with UQCRC1, NDUFS3 and SDHA as vital specific targets. Further experiments confirmed that I-PZH reduced TLR2, IL-17A and IL-1β, increased UQCRC1, SDHA, NDUFS3, promoted ATP synthesis and restored activity of mitochondrial respiratory chain complexes I and III in diabetic wounds. Metabolomics by HPLC-MS/MS analysis showed that I-PZH reversed multiple energy metabolism-related metabolites such as glucuronic acid, GMP, d-gluconic acid, cis-aconitic acid, ribose 5-phosphate and pantothenate.

CONCLUSION

This study highlights the important role of inflammation and energy generation in diabetic wound healing, reveals wound repair mechanism of PZH and promotes its clinical application in diabetic wound treatment.

Treatment Management of Diabetic Wounds Utilizing Herbalism: An Overview

BACKGROUND AND OBJECTIVES

Diabetes Mellitus, commonly known as DM, is a metabolic disorder which is characterized by high blood glucose level, i.e., chronic hyperglycemia. If it is not managed properly, DM can lead to many severe complexities with time and can cause significant damage to the kidneys, heart, eyes, nerves and blood vessels. Diabetic foot ulcers (DFU) are one of those major complexities which affect around 15-25% of the population diagnosed with diabetes. Due to diabetic conditions, the body's natural healing process slows down leading to longer duration for healing of wounds only when taken care of properly. Herbal therapies are one of the approaches for the management and care of diabetic foot ulcer, which utilizes the concept of synergism for better treatment options. With the recent advancement in the field of nanotechnology and natural drug therapy, a lot of opportunities can be seen in combining both technologies and moving towards a more advanced drug delivery system to overcome the limitations of polyherbal formulations.

METHODS

During the writing of this document, the data was derived from existing original research papers gathered from a variety of sources such as PubMed, ScienceDirect, Google Scholar.

CONCLUSION

Hence, this review includes evidence about the current practices and future possibilities of nano-herbal formulation in treatment and management of diabetic wounds.

Intensive Glycemic Control for Diabetic Foot Ulcer Healing: A Multicentric, Randomized, Parallel Arm, Single-Blind, Controlled Study Protocol (INGLOBE Study)

Hyperglycemia impairs healing of diabetic foot ulcer (DFU). But there is no evidence regarding benefit of intensive glucose control for healing of DFU. We plan to conduct a randomized, parallel arm, controlled study to assess the role of intensive glycemic management in comparison to conventional glucose control for healing of DFU. Participants with neuropathic DFU (infected or uninfected) having hemoglobin A1c (HbA1c) >8% and without evidence of osteomyelitis from 7 tertiary care hospitals will be enrolled. They will undergo a 2-week run-in phase for optimization of comorbidities, ulcer debridement, and counseling regarding self-monitoring of blood glucose (SMBG). Subsequently, they will be randomized to “intensive glycemic control” arm defined by glycemic targets of fasting blood glucose (FBG) <130 mg/dL, postprandial BG <180 mg/dL, and HbA1c <8%, with basal-bolus insulin regimen and frequent titration of insulin to achieve glycemic targets. The “conventional” arm will continue on prior treatment (oral antidiabetic drugs) with no titration unless meeting rescue criteria. Ulcer area will be calculated by automated wound assessment device (WoundlyClinial app) weekly for first 4 weeks, and less frequently until the 24th week. Standard treatment for DFU, off-loading, and counseling for foot care will be provided in both arms. The primary outcome measure will be number of wounds closed at 12th and 24th weeks. A multivariate regression analysis will be performed to identify the predictors of wound healing with baseline HbA1c, diabetes duration, wound size, wound duration, and background therapies as independent variable. This study will provide the much needed guidance to set optimum glucose targets in people with DFU.

Inhibition of CCL28/CCR10-Mediated eNOS Downregulation Improves Skin Wound Healing in the Obesity-Induced Mouse Model of Type 2 Diabetes

Chronic, nonhealing skin wounds, such as diabetic foot ulcers (DFUs), are common in patients with type 2 diabetes. Here, we investigated the role of chemokine (C-C motif) ligand 28 (CCL28) and its receptor C-C chemokine receptor type 10 (CCR10) in downregulation of endothelial nitric (NO) oxide synthase (eNOS) in association with delayed skin wound healing in the db/db mouse model of type 2 diabetes. We observed reduced eNOS expression and elevated CCL28/CCR10 levels in dorsal skin of db/db mice and subdermal leg biopsy specimens from human subjects with type 2 diabetes. Further interrogation revealed that overexpression of CCR10 reduced eNOS expression, NO bioavailability, and tube formation of human dermal microvascular endothelial cells (HDMVECs) in vitro, which was recapitulated in mouse dorsal skin. In addition, incubation of HDMVECs with CCL28 led to internalization of the CCR10/eNOS complex and colocalization with lysosome-associated membrane protein 1. Finally, topical application of myristoylated CCR10 binding domain 7 amino acid (Myr-CBD7) peptide prevented CCR10-eNOS interaction and subsequent eNOS downregulation, enhanced eNOS/NO levels, eNOS/VEGF-R2+ microvessel density, and blood perfusion, reduced inflammatory cytokine levels, and importantly, decreased wound healing time in db/db mice. Thus, endothelial cell CCR10 activation in genetically obese mice with type 2 diabetes promotes eNOS depletion and endothelial dysfunction, and targeted disruption of CCR10/eNOS interaction improves wound healing.

The Effects of Blue Light on Human Fibroblasts and Diabetic Wound Healing

Diabetes is a serious threat to global health and is among the top 10 causes of death. The Diabetic foot ulcer (DFU) is among the most common and severe complications of the disease. Bacterial infections are common; therefore, timely aggressive management, using multidisciplinary management approaches is needed to prevent complications, morbidity, and mortality, particularly in view of the growing cases of antibiotic-resistant bacteria. Photobiomodulation (PBM) involves the application of low-level light at specific wavelengths to induce cellular photochemical and photophysical responses. Red and near-infrared (NIR) wavelengths have been shown to be beneficial, and recent studies indicate that other wavelengths within the visible spectrum could be helpful as well, including blue light (400–500 nm). Reports of the antimicrobial activity and susceptibility of blue light on several strains of the same bacterium show that many bacteria are less likely to develop resistance to blue light treatment, meaning it is a viable alternative to antibiotic therapy. However, not all studies have shown positive results for wound healing and fibroblast proliferation. This paper presents a critical review of the literature concerning the use of PBM, with a focus on blue light, for tissue healing and diabetic ulcer care, identifies the pros and cons of PBM intervention, and recommends the potential role of PBM for diabetic ulcer care.

Circulating Biomarkers of Endothelial Dysfunction and Inflammation in Predicting Clinical Outcomes in Diabetic Patients with Critical Limb Ischemia

Critical limb ischemia (CLI) is a severe manifestation of peripheral artery disease characterized by ischemic pain, which is frequently associated with diabetes and non-healing lesions to inferior limbs. The clinical management of diabetic patients with CLI typically includes percutaneous transluminal angioplasty (PTA) to restore limb circulation and surgical treatment of diabetic foot ulcers (DFU). However, even after successful treatment, CLI patients are prone to post-procedure complications, which may lead to unplanned revascularization or foot surgery. Unfortunately, the factors predicting adverse events in treated CLI patients are only partially known. This study aimed to identify potential biomarkers that predict the disease course in diabetic patients with CLI. For this purpose, we measured the circulating levels of a panel of 23 molecules related to inflammation, endothelial dysfunction, platelet activation, and thrombophilia in 92 patients with CLI and DFU requiring PTA and foot surgery. We investigated whether these putative biomarkers were associated with the following clinical endpoints: (1) healing of the treated DFUs; (2) need for new revascularization of the limb; (3) appearance of new lesions or relapses after successful healing. We found that sICAM-1 and endothelin-1 are inversely associated with DFU healing and that PAI-1 and endothelin-1 are associated with the need for new revascularization. Moreover, we found that the levels of thrombomodulin and sCD40L are associated with new lesions or recurrence, and we show that the levels of these biomarkers could be used in a decision tree to assign patients to clusters with different risks of developing new lesions or recurrences.

IL1β/ TNFα/COX-2/VEGF axis responsible for effective healing potential of C-glucoside xanthone (mangiferin) based ointment in immunocompromised rats

Present study was conducted to undermine the wound healing potential of mangiferin vis a vis its molecular dynamics in immunocompromised excisional rat model. 120 rats were randomly and equally divided into five groups viz. group I (Healthy control), group II (Immunocompromised control), group III (Immunocompromised group treated with silver sulphadiazine), group IV (Immunocompromised group treated with 2.5 %Mangiferin) and group V (Immunocompromised group treated with 5 %Mangiferin). Immuno compromised state was achieved following intramuscular injection of Hydrocortisone @ 80 mg/kg body weight. Study was conducted for a period of 28 days. Six animals from each group were humanely sacrificed at weekly interval till day 28th of study. Planimetric analysis, biochemical studies viz. hydroxyproline assay, total protein and DNA content, antioxidative potential through LPO assay was done along with molecular studies involving expression profiling of IL1β, TNFα and COX-2 and Immunohistochemistry of angiogenic marker i.e. VEGF was performed to undermine the pharmacodynamics of mangiferin. Histopathological studies including H&E and Masson's Trichome was also performed to study histoarchitectural changes in wound healing and reparative process following application of mangiferin ointment. Study revealed significant (P ≤ 0.05) reduction in wound area measurement and significant (P ≤ 0.05) increase in wound contraction (%) following mangiferin administration in immunocompromised rats. Hydroxyproline, DNA and total protein showed significant (P ≤ 0.05) increase in skin tissues of mangiferin treated immunocompromised rats. LPO assay revealed significant (P ≤ 0.05) reduction in mangiferin treated animals. Histopathological studies of skin tissues revealed complete restoration advocating grade III of healing in 2.5% mangiferin treated group. Higher expression and strong signal intensity of VEGF was noticed in 2.5% mangiferin treatment group along with significant (P ≤ 0.05) upregulation IL1β and TNFα on day 7 in 2.5% mangiferin treatment group with significant (P ≤ 0.05) down regulation of COX-2 in mangiferin treatment group as compared to other groups i.e. group II and III. It is concluded from our study that mangiferin facilitates wound healing through improved wound closure, organized deposition of collagen deposition and granulation matrix formation.

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.

Nrf2 driven macrophage responses in diverse pathophysiological contexts: Disparate pieces from a shared molecular puzzle

The wide anatomical distribution of macrophages and their vast array of functions match various polarization states and their involvement in homeostasis and disease. The confluence of different cellular signaling networks, including direct involvement in inflammation, at the doorstep of the transcription factor Nuclear Factor- erythroid (NF-E2) p45-related factor 2 (Nrf2) activation raises the importance of deciphering the molecular circuitry at the background of multiple-discrete and antagonistic yet flexible and contextual pathways. While we primarily focus on wound healing and repair mechanisms that are affected in diabetic foot ulcers (DFUs), we strive to explore the striking similarities and differences in molecular events including inflammation, angiogenesis, and fibrosis during tissue injury and wound persistence that accumulates pro-inflammatory senescent macrophages, as a means to identify possible targets or cellular mediators to lessen DFU disease burden. In addition, the role of iron in the modulation of Nrf2 response in macrophages is crucial and reviewed here. Targeted approaches, unlike conventional treatments, in DFU management will require the review and re-assessment of mediators with relevance to other pathological conditions.

Diabetes complications and extracellular vesicle therapy

Diabetes is a chronic disorder characterized by dysregulated glycemic conditions. Diabetic complications include microvascular and macrovascular abnormalities and account for high morbidity and mortality rates in patients. Current clinical approaches for diabetic complications are limited to symptomatic treatments and tight control of blood sugar levels. Extracellular vesicles (EVs) released by somatic and stem cells have recently emerged as a new class of potent cell-free therapeutic delivery packets with a great potential to treat diabetic complications. EVs contain a mixture of bioactive molecules and can affect underlying pathological processes in favor of tissue healing. In addition, EVs have low immunogenicity and high storage capacity while maintaining nearly the same regenerative and immunomodulatory effects compared to current cell-based therapies. Therefore, EVs have received increasing attention for diabetes-related complications in recent years. In this review, we provide an outlook on diabetic complications and summarizes new knowledge and advances in EV applications. Moreover, we highlight recommendations for future EV-related research.

Huangbai liniment and berberine promoted wound healing in high-fat diet/Streptozotocin-induced diabetic rats

Diabetic ulcer is a challenging complication of diabetes mellitus but current treatments cannot achieve satisfactory results. In this study, the effect of Huangbai liniment (HB) and berberine on the wound healing in high fat diet/streptozotocin injection induced diabetic rats was investigated by RNA-seq technology. HB topical treatment promoted wound healing in the diabetic patients and diabetic rats, and it affected multiple processes, of which IL-17 signalling pathway was of importance. Inhibiting IL-17a by its inhibitor or antibody remarkably facilitated wound healing and HB significantly repressed the high IL-17 expression and its downstream targets, including Cxcl1, Ccl2, Mmp3, Mmp9, G-CSF, IL1B and IL6, in diabetic wounds, promoted T-AOC, SOD activity and GSH levels; decreased the levels of nitrotyrosine and 8-OHdG; enhanced angiogenesis-related CD31, PDGF-BB and ANG1 expression; inhibited cleaved caspase-3 levels and promoted TIMP1 and TGFB1. Moreover, berberine (a major component in HB) repressed the IL-17 signalling pathway, and promoted wound healing in diabetes mellitus. This study highlights the strategy of targeting IL-17a in diabetic wounds, deepens the understanding of wound healing in diabetes mellitus in a dynamic way and reveals the characteristics of HB and berberine in promoting wound healing of type 2 diabetes mellitus.

Three-layered PCL-collagen nanofibers containing melilotus officinalis extract for diabetic ulcer healing in a rat model

Active wound dressing with physicochemical and biological characteristics is more effective in healing diabetic foot ulcer (DFU). In this study, a 3-layer electrospun nanofiber wound dressings was fabricated, while its outer, middle and inner layers of the scaffold were made of PCL, PCL/collagen and collagen nanofibers, respectively. Various amounts of Melilotus officinalis extract were also loaded in the collagen nanofibers as a biologically active compound. The diameter and morphology of the obtained nanofibers were investigated by scanning electron microscopy (SEM) and FT-IR spectroscopy to analyse the composition of prepared dressings. The efficacy of the fabricated dressings as wound healing agent was assessed in streptozotocin-induced diabetic rats. The results demonstrated that the mean diameter of nanofibers are 373 ± 179 nm, 266 ± 108 nm, 160 ± 52 nm, and 393 ± 131 nm for PCL, PCL/collagen, pure collagen, and collagen nanofibers containing 0.08 g extract, respectively. The histo-pathology and histomorphometry assessments demonstrate the herbal extract-loaded electrospun dressings (especially containing 0.08 g of the extract) are promising in improving the diabetic ulcer healing. Our results indicated that the combination of drug did not compromise the physicochemical characteristics of wound dressing, while improving its biological activities.

Ozone improved the wound healing in type 2 diabetics via down-regulation of IL- 8, 10 and induction of FGFR expression

Background and aim:

We aimed to investigate the effect of ozonated autohaemotherapy (OA) on the wound healing, serum values of interleukin (IL) - 6, 8, 10, tumor necrosis factor-alpha (TNF-α), basic fibroblast growth factor (bFGF) and local expression of fibroblast growth factor receptors (FGFR) in type 2 diabetics with the acute soft-tissue infections.

Methods:

Patients in the first cohort (n-30) received a basic comprehensive treatment (BCT-group), and the second (n=28) also received OA (OA-group). Blood samples for ELISA and tissue specimens for the immunohistochemical examinations were collected at admission (day 0) and at the 9th day of inpatient treatment.

Results:

The additional using of OA has accelerated the timing of a single and the complete wound granulation and the timing to marginal epithelization, compared with the results of the standard treatment. The use of OA has significantly reduced the production of IL-8, 10 at 9th day. OA-group patients were characterized by consistently high levels of bFGF production in contrast to the BCT-group, where the decreasing in the serum bFGF level was observed. The maximum number of bFGFR - immunopositive labels was observed in OA-group out to 9th day (319,45 (249,90-348,43) versus baseline 192,65 (171,93-207,72), versus BCT-group 123,30 (105,23- 141,10), p<0,001).

Conclusions:

Application of OA in the complex treatment of the acute soft-tissue infections in diabetics makes it possible to achieve the significant reductions in the duration of the wound inflammation and regeneration phases by eliminating of overproduction of IL- 8, 10 and induction of expression of bFGF and its receptors. (www.actabiomedica.it)

Combinatorial Therapeutic Strategy of Biogenics Derived from Lactobacillus fermentum PUM and Zingerone Against Pseudomonas aeruginosa PAO1-Induced Surgical Site Infection: an Experimental Study

Pseudomonas aeruginosa, a WHO-prioritized multidrug-resistant Gram-negative bacteria, is one of the frequently implicated pathogen in surgical site infection (SSI) due to its virulence phenotypes and biofilm-forming ability. In the present study, cell-free supernatant (CFS) and biogenics (organic acids and precipitated protein fraction) of indigenous potential probiotic, Lactobacillus fermentum PUM both alone and in combination with zingerone were found to inhibit pyocyanin, pyochelin, protease, elastase, the virulence factors, and motility of P. aeruginosa PAO1. Furthermore, scanning electron microscopy indicated that biofilm formation was attenuated maximally by CFS of L. fermentum combined with zingerone. In vivo study revealed reduced P. aeruginosa burden, suppuration at surgical site vis-a-vis reduced levels of oxidants, pro-inflammatory cytokines, ameliorated anti-oxidants, and healed infected surgical site compared with counter controls. In totality, combination of L. fermentum PUM-derived biogenics and zingerone could be employed to treat P. aeruginosa-induced SSI that needs to be correlated clinically.

Stem and Somatic Cell Monotherapy for the Treatment of Diabetic Foot Ulcers: Review of Clinical Studies and Mechanisms of Action

Diabetic foot ulcer (DFU) is one of the most severe complications of diabetes mellitus, often resulting in a limb amputation. A cell-based therapy is a highly promising approach for an effective DFU treatment. However, there is no consensus regarding the most effective cell type for DFU treatment. Various cell types contribute to chronic wound healing via different mechanisms. For example, application of keratinocytes can stimulate migration of native keratinocytes from the wound edge, while mesenchymal stem cells can correct limb ischemia. To assess the effectiveness of a certain cell type, it should be administered as a monotherapy without other substances and procedures that have additional therapeutic effects. In the present review, we described therapeutic effects of various cells and provided an overview of clinical studies in which stem and somatic cell-based therapy was administered as a monotherapy. Topical application of somatic cells contributes to DFU healing only, while injection of mesenchymal stem cells and mononuclear cells can break a pathophysiological chain leading from insufficient blood supply to DFU development. At the same time, the systemic use of mesenchymal stem cells carries greater risks. Undoubtedly, cell therapy is a potent tool for the treatment of DFU. However, it is vital to conduct further high-quality clinical research to determine the most effective cell type, dosage and way of administration for DFU treatment. Ischemia, neuropathy and neuro-ischemia are underlying factors of diabetic foot ulcer. Stem and somatic cells monotherapy can improve chronic wound healing via different mechanisms.

Carboxymethyl chitosan-grafted polyvinylpyrrolidone-iodine microspheres for promoting the healing of chronic wounds

Chronic wounds that fail to heal are the most common complications experienced by diabetic patients, and current treatment remains unsatisfactory, mainly due to the vulnerability of diabetic wounds to bacterial infections. Chitosan derivatives are widely used to treat chronic wounds due to their excellent hydrophilicity, biodegradability, and antimicrobial activity and substantial contribution to tissue regeneration. However, the antimicrobial effect of chitosan is not sufficient due to the complicated pathological mechanism of diabetes mellitus. Here, we prepared carboxymethyl chitosan-grafted polyvinylpyrrolidone-iodine (CMC-g-PVPI) microspheres and used them to treat chronic wounds. Carboxymethyl chitosan (CMC) was used as the skeleton and was grafted with polyvinylpyrrolidone-iodine (PVPI) to form a CMC-g-PVPI complex hydrogel and CMC-g-PVPI microspheres, which formed as a result of the high shearing dispersion of the complex hydrogel. In vivo experiments on diabetic wounds revealed significantly accelerated wound closure in the presence of the microspheres, demonstrating the excellent potential of CMC-g-PVPI to promote skin wound regeneration under diabetic conditions.

Roles of MicroRNA-21 in Skin Wound Healing: A Comprehensive Review

MicroRNA-21 (miR-21), one of the early mammalian miRNAs identified, has been detected to be upregulated in multiple biological processes. Increasing evidence has demonstrated the potential values of miR-21 in cutaneous damage and skin wound healing, but lack of a review article to summarize the current evidence on this issue. Based on this review, relevant studies demonstrated that miR-21 played an essential role in wound healing by constituting a complex network with its targeted genes (i.e., PTEN, RECK. SPRY1/2, NF-κB, and TIMP3) and the cascaded signaling pathways (i.e., MAPK/ERK, PI3K/Akt, Wnt/β-catenin/MMP-7, and TGF-β/Smad7-Smad2/3). The treatment effectiveness developed by miR-21 might be associated with the promotion of the fibroblast differentiation, the improvement of angiogenesis, anti-inflammatory, enhancement of the collagen synthesis, and the re-epithelialization of the wound. Currently, miRNA nanocarrier systems have been developed, supporting the feasibility clinical feasibility of such miR-21-based therapy. After further investigations, miR-21 may serve as a potential therapeutic target for wound healing.

Effect of a Topical Gel Based on Adelmidrol + Trans-Traumatic Acid in the Treatment of Diabetic Foot Ulcers: An Open-Label Study

BACKGROUND

Diabetic foot ulceration is a severe complication of diabetes characterized by chronic inflammation and impaired wound healing. This study aimed to evaluate the effect of a medical device gel based on adelmidrol + trans-traumatic acid in the healing process of diabetic foot ulcers.

METHODS

Thirty-seven diabetic patients with foot ulcers of mild/moderate grade were treated with the gel daily for 4 weeks on the affected area. The following parameters were evaluated at baseline and weekly: 1) wound area, measured by drawing a map of the ulcer and then calculated with photo editing software tools, and 2) clinical appearance of the ulcer, assessed by recording the presence/absence of dry/wet necrosis, infection, fibrin, neoepithelium, exudate, redness, and granulation tissue.

RESULTS

Topical treatment led to progressive healing of diabetic foot ulcers with a significant reduction of the wound area and an improvement in the clinical appearance of the ulcers. No treatment-related adverse events were observed.

CONCLUSIONS

The results of this open-label study show the potential benefits of adelmidrol + trans-traumatic acid topical administration to promote reepithelialization of diabetic foot ulcers. Further studies are needed to confirm the observed results.