Chronic Non-healing Diabetic Foot Research Articles

3D Porous Polymer Scaffold-Conjugated KGF-Mimetic Peptide Promotes Functional Skin Regeneration in Chronic Diabetic Wounds.

The re-epithelialization process gets severely dysregulated in chronic nonhealing diabetic foot ulcers/wounds. Keratinocyte growth factor (KGF or FGF-7) is the major modulator of the re-epithelialization process, which regulates the physiological phenotypes of cutaneous keratinocytes. The existing therapeutic strategies of growth factor administration have several limitations. To overcome these, we have designed a KGF-mimetic peptide (KGFp, 13mer) based on the receptor interaction sites in murine KGF. KGFp enhanced migration and transdifferentiation of mouse bone marrow-derived MSCs toward keratinocyte-like cells (KLCs). A significant increase in the expression of skin-specific markers Bnc1 (28.5-fold), Ck5 (14.6-fold), Ck14 (26.1-fold), Ck10 (187.7-fold), and epithelial markers EpCam (23.3-fold) and Cdh1 (64.2-fold) was associated with the activation of ERK1/2 and STAT3 molecular signaling in the KLCs. Further, to enhance the stability of KGFp in the wound microenvironment, it was conjugated to biocompatible 3D porous polymer scaffolds without compromising its active binding sites followed by chemical characterization using Fourier transform infrared spectroscopy, field-emission scanning electron microscopy, dynamic mechanical analysis, and thermogravimetry. In vitro evaluation of the KGFp-conjugated 3D polymer scaffolds revealed its potential for transdifferentiation of MSCs into KLCs. Transplantation of allogeneic MSCGFP using KGFp-conjugated 3D polymer scaffolds in chronic nonhealing type 2 diabetic wounds (db/db transgenic, 50-52 weeks old male mice) significantly enhanced re-epithelialization-mediated wound closure rate (79.3%) as compared to the control groups (Untransplanted -22.4%, MSCGFP-3D polymer scaffold -38.5%). Thus, KGFp-conjugated 3D porous polymer scaffolds drive the fate of the MSCs toward keratinocytes that may serve as potential stem cell delivery platform technology for tissue engineering and transplantation.

Gene therapy for diabetic foot ulcers: Interim analysis of a randomised, placebo-controlled phase 3 study of VM202 (ENGENSIS), a plasmid DNA expressing two isoforms of human hepatocyte growth factor.

To evaluate the status of a 7-month phase 3 study conducted to test the effect of intramuscular injections of VM202 (ENGENSIS), a plasmid DNA encoding human hepatocyte growth factor, into the calf muscles of chronic nonhealing diabetic foot ulcers with concomitant peripheral artery disease. The phase 3 study, originally aimed to recruit 300 subjects, was discontinued because of slow patient recruitment. An unprespecified interim analysis was performed for the 44 subjects enrolled to assess the status and determine the future direction. Statistical analyses were carried out for the Intent-to-Treat (ITT) population and separately for subjects with neuroischemic ulcers, using a t-test and Fisher's exact test. A logistic regression analysis was also conducted. VM202 was safe and potentially should have benefits. In the ITT population (N = 44), there was a positive trend toward closure in the VM202 group from 3 to 6 months but with no statistical significance. Levels of ulcer volume or area were found to be highly skewed between the placebo and VM202 groups. Forty subjects, excluding four outliers in both arms, showed significant wound-closing effects at month 6 (P = .0457). In 23 patients with neuroischemic ulcers, the percentage of subjects reaching complete ulcer closure was significantly higher in the VM202 group at months 3, 4, and 5 (P = .0391, .0391, and .0361). When two outliers were excluded, a significant difference was evident in months 3, 4, 5, and 6 (P = .03 for all points). A potentially clinically meaningful 0.15 increase in Ankle-Brachial Index was observed in the VM202 group at day 210 in the ITT population (P = .0776). Intramuscular injections of VM202 plasmid DNA to calf muscle may have promise in the treatment of chronic neuroischemic diabetic foot ulcers (DFUs). Given the safety profile and potential healing effects, continuing a larger DFU study is warranted with modifications of the current protocol and expansion of enrolling sites.

A Study on Prevalence, Profile, and Risk Factors of Developing Fungal Infection in Patients With Diabetic Foot Ulcer

Background: Many chronic nonhealing diabetic foot ulcers (DFUs) with increased rates of amputation are frequently associated with fungal infections. Purpose: To evaluate the prevalence, profile, and risk factors of developing a fungal infection in patients with DFU. Methods: This prospective observational study was carried out from October 2018 to July 2020. All adult patients with DFUs admitted to the surgery ward were recruited. Patients on antifungal therapy or who received such therapy within 6 weeks prior to admission were excluded. Three deep tissue samples were sent for bacterial culture, fungal culture, and histopathological examination of fungal elements. Results: A total of 251 patients were enrolled in the study. Of the 23.3% of patients with positive fungal growth (n = 47/202), 2% (n = 4/202) had pure fungal growth and 21.3% (n = 43/202) had mixed growth with bacteria in their ulcers (ie, non-contaminated samples). A significant association was found between wound grade (P = .027), ulcer duration (P = .028), and positive fungal growth in DFUs. Conclusions: In this study, the prevalence of fungal infection in DFUs was 23.3%; Candida tropicalis (27.08%) was the most common isolate, followed by C. albicans (20.83%). The rate of fungal infections was high in patients with mild diabetic foot infection or DFU of 7 to 14 days’ duration.

Efficacy of Platelets Rich Plasma as A Therapeutic Tool in Chronic Non-Healing Diabetic Foot Ulcers

Efficacy of Platelets Rich Plasma as A Therapeutic Tool in Chronic Non-Healing Diabetic Foot Ulcers

The role of CXCL8 in chronic nonhealing diabetic foot ulcers and phenotypic changes in fibroblasts: a molecular perspective

A persistent inflammation is perpetuated by infiltrating immune cells and cytokines secreted from these immune cells. Additionally, apoptotic keratinocytes and adipocytes in diabetes causes diabetic foot ulcer (DFU) to arrest in an inflammatory phase without progressing to the resolution phase. This leads to a nonhealing DFU and, despite advanced treatments consisting of wound debridement, off-loading the ulcer of necrotic tissue, wound dressings to keep it moist and control exudate, medication, and preventing infection, DFUs remain a clinical problem. Nonhealing DFUs pose not only an economic burden but also increased morbidity and mortality in the form of psychological stress with and increased chance of amputation, and even death. Thus, investigating the complicated underlying molecular mechanism responsible for nonhealing patterns and designing better therapeutics is warranted. This review article focuses on the role of IL-8-mediated persistent inflammation and phenotypic change of fibroblasts due to this inflammatory cascade. We have discussed various sources of interleukin (IL)-8 secretion and the possible association of IL8-fibroblast plasticity as a cause of nonhealing DFUs. A literature search on PubMed, Google Scholar, and PMC was done including the terms diabetic foot ulcer, diabetes, diabetic ulcer, chronic inflammation, interleukin 8, diabetic wound, and nonhealing diabetic foot ulcers. The articles in the English language and published in last 10 years were selected. From the pool of these, the articles describing the relationship between IL-8 and nonhealing diabetic foot ulcer and diabetic ulcer were used sorted out and used for this review article following PRISMA guidelines. Increased infiltration of inflammatory immune cells, secretion of pro-inflammatory cytokines, altered keratinocyte-fibroblast function, and phenotypic changes of fibroblasts in DFUs seem to be critical to the nonhealing of DFUs. Thus, inhibiting IL-8 secretion and downstream signaling seems to be a goal of potential therapeutics.

A comparative study on effect of platelet rich plasma Vs conventional dressing in healing rate of chronic diabetic ulcers

Introduction and Aim: This study has been undertaken to evaluate efficacy of platelet rich plasma (PRP) dressing that is recently introduced with conventional dressing. We have tried to compare PRP dressing with conventional normal dressing in healing the wound. Materials and Methods: We conducted this study in 120 patients of chronic non healing diabetic foot ulcers who were treated over the period of three years. Number of cases (60 each) were studied for efficacy of applying autologous platelet rich plasma versus normal dressing for chronic non healing diabetic foot ulcers. At every week follow up, the ulcer was examined for granulation tissue, area and volume which was calculated using Vernier calipers and marked on a graph paper and photographs were taken. Wound healing was compared between PRP and normal dressing. Results: The incidence of male susceptibility was more (70%) than females (30%) in diabetic foot. Average rate of healing per week was found to be significantly better among the PRP group than normal dressing group. The ulcer showed significant reduction in size among the PRP group in comparison to the normal dressing group with a significant P value (0.001). Conclusion: In this study application of platelet rich plasma into chronic non-healing diabetic foot ulcers in comparison with conventional dressing has shown a significant reduction in the size of the ulcer, hospital stay and cost for the patient.

Microbial Community Distribution and Core Microbiome in Successive Wound Grades of Individuals with Diabetic Foot Ulcers.

Diabetic foot ulcer (DFU) is a major complication of diabetes with high morbidity and mortality rates. The pathogenesis of DFUs is governed by a complex milieu of environmental and host factors. The empirical treatment is initially based on wound severity since culturing and profiling the antibiotic sensitivity of wound-associated microbes is time-consuming. Hence, a thorough and rapid analysis of the microbial landscape is a major requirement toward devising evidence-based interventions. Toward this, 122 wound (100 diabetic and 22 nondiabetic) samples were sampled for their bacterial community structure using both culture-based and next-generation 16S rRNA-based metagenomics approach. Both the approaches showed that the Gram-negative microbes were more abundant in the wound microbiome. The core microbiome consisted of bacterial genera, including Alcaligenes, Pseudomonas, Burkholderia, and Corynebacterium in decreasing order of average relative abundance. Despite the heterogenous nature and extensive sharing of microbes, an inherent community structure was apparent, as revealed by a cluster analysis based on Euclidean distances. Facultative anaerobes (26.5%) were predominant in Wagner grade 5, while strict anaerobes were abundant in Wagner grade 1 (26%). A nonmetric dimensional scaling analysis could not clearly discriminate samples based on HbA1c levels. Sequencing approach revealed the presence of major culturable species even in samples with no bacterial growth in culture-based approach. Our study indicates that (i) the composition of core microbial community varies with wound severity, (ii) polymicrobial species distribution is individual specific, and (iii) antibiotic susceptibility varies with individuals. Our study suggests the need to evolve better-personalized care for better wound management therapies.IMPORTANCE Chronic nonhealing diabetic foot ulcers (DFUs) are a serious complication of diabetes and are further exacerbated by bacterial colonization. The microbial burden in the wound of each individual displays diverse morphological and physiological characteristics with unique patterns of host-pathogen interactions, antibiotic resistance, and virulence. Treatment involves empirical decisions until definitive results on the causative wound pathogens and their antibiotic susceptibility profiles are available. Hence, there is a need for rapid and accurate detection of these polymicrobial communities for effective wound management. Deciphering microbial communities will aid clinicians to tailor their treatment specifically to the microbes prevalent in the DFU at the time of assessment. This may reduce DFUs associated morbidity and mortality while impeding the rise of multidrug-resistant microbes.

CT Scan of the Foot in Patients with Chronic Non-Healing Diabetic Foot Ulcer

Background: Diabetes mellitus is a chronic disease where there is an increased blood sugar level in the body which is either caused due to inability of the pancreas to secrete insulin or the body’s inability to utilize it. The prevalence of diabetes mellitus is growing rapidly worldwide. Statistics show that in the year 2014, there were a total of 422 million cases of DM. Diabetes mellitus is a major cause of heart attacks, kidney failure, blindness and leg amputations. Diabetic foot ulcers are quite common and are estimated to affect nearly 15% of all diabetic patients during their lifetime. In long standing diabetic patients with chronic non-healing ulcers, bony changes or deformities are not uncommon. These bony changes can be identified using CT scans. Materials and Methods: An observational study was conducted on a total of 40 patients with chronic non-healing ulcer attending the surgery outpatient department of Saveetha Medical College, Chennai, Tamilnadu. The CT-scans of their foot were observed for deformities or bony changes. Results: Out of 40 patients, 67.5% were males and 32.5% were females. A maximum number of subjects fell under the age group of 51 - 60 years. The most common site of the ulcer was found to be in the plantar surface of big toe (53%). Among the 40 patients, 33 of them were found to have bony abnormalities on the CT scan of foot and no apparent changes were seen in the rest. Bone erosions (35%), osteopenic changes (22.5%), Charcot’s joint (2.5%), osteophyte formation (12.5) and reduced joint space (10%) were the predominant changes observed on the CT scans of the study population.

Assessment of Mineral Pathophysiology in Patients with Diabetic Foot Ulcer.

Chronic non-healing diabetic foot ulcers (DFU) with a recurrence rate of over 50% in 3years account for more than 1,08000 non-traumatic lower extremity amputations. Reports of altered mineral status and their role in pathogenesis of diabetes are well documented. However, little is known regarding their status and impact on severity of complications like foot ulcer. A hospital-based case control study was conducted in 64 subjects aged 40-60years, attending the Podiatric and the Diabetes clinic of the institutional hospitals. Study subjects included were 32 diagnosed cases of type 2 diabetes having foot ulcers along with 32 age-matched diabetics without foot ulcer as controls. Fasting and post-prandial plasma glucose were estimated by glucose oxidase peroxidase method and HbA1c by high-performance liquid chromatography method. Serum zinc, magnesium and copper levels were estimated by colorimetric methods in semi-autoanalyser. Serum levels of zinc, copper and magnesium were significantly decreased in DFU cases as compared with diabetics without ulcers (p < 0.05). Correlation analysis revealed a significant inverse correlation of these minerals with all the glycaemic indices; the association being the strongest in case of zinc in both groups. The higher degree of mineral insufficiencies in the foot ulcer group of this study could be responsible for worsening the glycaemic control in diabetics leading to delayed healing of foot ulcers. The observed decrease of serum copper, magnesium and zinc levels in diabetics with foot ulcers appears to be proportionally related to the length of the diabetic disease. Thus, continuous monitoring and dietary supplementation of minerals in case of severe deficiencies might be beneficial in halting the progression of such complications.

Application of Topical Oxygen Therapy in Healing Dynamics of Diabetic Foot Ulcers - A Systematic Review.

Individuals with diabetes may develop diabetic foot ulcers due to diabetic peripheral neuropathy. Multiple factors influence the ulcer healing process; oxygen helps in facilitating the different stages of wound healing. The objective of this systematic review was to analyze the different levels of evidence available in the application of topical oxygen therapy, warm oxygen therapy, or other modes of topical oxygen delivery in the healing dynamics of diabetic foot ulcers. Databases searched included Pubmed/Medline, Science Direct, Web of Science, Scopus, Cochrane, and CINAHL. The eligibility criteria of studies included participants ≥18 years with chronic non-healing diabetic foot ulcer (duration ≥3 months) receiving warm oxygen or topical oxygen therapy (TOT), and other modes of topical oxygen administration, which were compared with standard care group. Randomized and non-randomized studies were included. The primary outcome measure assessed was the rate of wound healing or wound closure. The review included 5 studies which used different modes of topical oxygen administration. The healing trajectory of the wounds was completely achieved in low-grade ulcers (grade 1), whereas all high-grade ulcers (grades 2, 3, and above) showed either 100% or 50% healing with a reduction in ulcer size and ulcer tissue depth. Topical oxygen therapy facilitates wound healing dynamics among individuals with chronic diabetic foot ulcers.

Cutaneous squamous carcinoma in a patient with diabetic foot: an unusual evolution of a frequent complication.

SummaryAfter basal cell carcinoma, the cutaneous squamous cell carcinoma (cSCC) is the second most frequent non-melanoma skin cancer worldwide, and, classically, arises from the upper coats of the epidermis of sun-exposed areas or from skin areas constantly exposed to a chronic inflammatory stimulus. The occurrence of cSCC seems to be linked to several factors, including exposure to sunlight (or other ultraviolet radiations), immunosuppression, chronic scarring conditions and some familial cancer syndromes. Although the majority of cSCCs are adequately eradicated by surgical excision, a subgroup of cSCC may be linked with an increased risk of recurrence, metastasis and death. The incidence of type 2 diabetes mellitus is constantly increasing worldwide. Importantly, diabetes mellitus is a strong risk factor for cancers (including cutaneous tumors) and is highly related with poor cancer outcomes. At present, in the literature, squamous cell carcinoma developing in association with diabetic foot ulcers has been already reported in some reports; however, additional data are needed to make the clinicians aware of this rare, although possible, complication. Therefore, we herein report an unusual case of an elderly man with T2DM and a positive oncological history, presenting a cSCC involving the skin overlying the first toe of left foot. The growing cSCC appeared approximately 3 years after the appearance of a diabetic ulcer.Learning points:Diabetic foot ulcers are an important and severe complication of diabetes mellitus and often can result in foot amputation.Chronic and non-healing diabetic foot ulcers are often observed in clinical practice.Clinicians should always take into consideration the malignant degeneration (e.g., cutaneous squamous cell carcinoma) of any chronic non-healing diabetic foot ulcer in elderly T2DM individuals.Timely surgical resection of a chronic, non-healing diabetic foot ulcer might preclude the development of a cutaneous squamous cell carcinoma.

Topical application of Hydroxysafflor Yellow A accelerates the wound healing in streptozotocin induced T1DM rats

To investigate the effects of Hydroxysafflor Yellow A (HSYA), which is derived from safflower, on the proliferation, migration and angiogenesis of cells in vitro and its potential efficacy in vivo when topically applied to a diabetic wound. Human umbilical vein endothelial cells (HUVECs) and mouse macrophage cells (RAW264.7) were used to evaluate angiogenesis and anti-inflammatory activities, respectively. The influence of HSYA on the wound scratch assay was investigated in keratinocytes. A splinted excisional wound model in rats with TIDM induced by streptozotocin was used to assess the effects of wound healing. Collagen disposition and secretion of vascular growth factors (VEGF) as well as transforming growth factor-β1 (TGF-β1) were evaluated by an ELISA assay and histological staining. The in vitro results showed that HSYA could significantly enhance both the neovascularization of HUVECs and the migration of keratinocytes. It showed the significant inhibitory effect on nitric oxide production, indicating the anti-inflammatory activity of HSYA. In vivo, the topical application of HSYA significantly enhanced the wound closure rate, and the time to complete wound closure was 17 days, whereas 30 days were needed with PBS treatment. Further, treatment with HSYA exhibited significant granulation tissue formation with higher collagen content, re-epithelialization and angiogenesis according to Masson's trichrome staining evaluation, VEGE and TGF-β1 ELISA measurement. In conclusion, HSYA application could be considered a promising therapeutic strategy for treating chronic non-healing diabetic foot ulcers.

Effect of cadexomer iodine on the microbial load and diversity of chronic non-healing diabetic foot ulcers complicated by biofilm in vivo.

Objectives: The performance of cadexomer iodine was determined against microbial populations from chronic non-healing diabetic foot ulcers (DFUs) complicated by biofilm in vivo, using molecular, microscopy and zymography methods. Methods: Chronic non-healing DFUs due to suspected biofilm involvement were eligible for enrolment. DNA sequencing and real-time quantitative PCR was used to determine the microbial load and diversity of tissue punch biopsies obtained pre- and post-treatment. Scanning electron microscopy and/or fluorescence in situ hybridization confirmed the presence or absence of biofilm. Zymography was used to determine levels of wound proteases. Results: Seventeen participants were recruited over a 6 month period. Scanning electron microscopy and or fluorescence in situ hybridization confirmed the presence of biofilm in all samples. Eleven participants exhibited log10 reductions in microbial load after treatment (range 1–2 log10) in comparison with six patients who experienced <1 log10 reduction (P = 0.04). Samples were tested for levels of wound proteases pre- and post-treatment. Reductions in the microbial load correlated to reductions in wound proteases pre- and post-treatment (P = 0.03). Conclusions: To the best of our knowledge, this study represents the first in vivo evidence, employing a range of molecular and microscopy techniques, of the ability of cadexomer iodine to reduce the microbial load of chronic non-healing DFUs complicated by biofilm. Further analyses correlating log reductions to optimal duration of therapy and improvements in clinical parameters of wound healing in a larger cohort are required.

Botulinum A toxin versus external fixator in the management of diabetic foot ulcer

Objective The purpose of this study was to describe the use of dermal fillers in the treatment of large, soft-tissue defects in diabetic foot with and without the use of external fixation of the foot. Patients and methods Thirteen patients with chronic nonhealing diabetic foot ulcer for several weeks to months were included in the study. There were 11 male and two female patients. Seven patients (three female and four male) were randomly assigned to the Botox injection group, and six patients (four female and two male) were randomly assigned to the external fixator group. The mean ± SD age of patients was 55 ± 10 years. Results At 12 weeks, the proportion of healing was significantly higher in the Botox with an external frame group than in the Botox alone group (89.5 vs. 61.4%, P = 0.026). At final follow-up, 12 (92.3%) patients were ambulatory with a regular or custom shoe and had a good result based on our defined criteria. There were no complications from the injections. Conclusion The use of Botox together with an external fixator is an attractive choice to off-load diabetic foot ulcer.

Initial report of the use of an injectable porcine collagen‐derived matrix to stimulate healing of diabetic foot wounds in humans

A novel injectable scaffolding matrix (E-Matrix) has been developed to accelerate wound healing in diabetic foot ulcers. This porcine collagen-derived matrix is designed to mimic tertiary embryonic connective tissue and to stimulate fetal wound repair mechanisms including angiogenesis. In vitro and animal studies have indicated a beneficial effect on tissue growth and an acceptable safety profile. In this report, we describe the initial use of this product in a pilot study of six humans with chronic nonhealing diabetic foot ulcers. A dramatic initial response to injection was seen, with an average wound size reduction of 72% 2 weeks after injection. Randomized trials are underway to define the potential benefit of this new treatment modality for diabetic foot ulcers.