Negative pressure wound therapy use in diabetic foot syndrome-from mechanisms of action to clinical practice

Effects of different treatment measures on the efficacy of diabetic foot ulcers: a network meta-analysis

Introduction

Through a network meta-analysis, we compared different treatment measures for patients with diabetic foot ulcers (DFU), assessing their impact on the healing of DFU and ranking them accordingly.

Methods

We searched the PubMed, the China National Knowledge Infrastructure (CNKI), Embase, the WanFang and the WeiPu database. The retrieval time was from database establishment to January 2024, and retrieval entailed subject and free words. Randomized controlled trials (RCTs) with different treatment measures for DFU were included. Data extraction and evaluation were based on the PRISMA guidelines. Meta-analyses using pairwise and network methods were employed to compare and rank the effectiveness of different treatments for DFU.

Results

Ultimately, we included 57 RCTs involving a total of 4,826 patients with DFU. When it comes to ulcer healing rates, compared to standard of care(SOC),platelet-rich plasma(PRP), hyperbaric oxygen therapy(HBOT), topical oxygen therapy(TOT), acellular dermal matrix(ADM), and stem cells(SCs) in both direct meta-analysis(DMA) and network meta-analysis(NMA) can effectively increase the complete healing rate. For Scs+PRP, a statistically significant improvement was only observed in the NMA. Moreover, when compared to the negative pressure wound therapy(NPWT) group, the PRP+NPWT group was more effective in promoting the complete healing of ulcers. In terms of promoting the reduction of ulcer area, no statistical differences were observed among various treatment measures. When it comes to ulcer healing time, both PRP and NPWT can effectively shorten the healing time compared to SOC. Furthermore, when compared to the NPWT group, the combined treatment of PRP and ultrasonic debridement(UD) with NPWT is more effective in reducing healing time. In terms of amputation rates and adverse reactions, the PRP group effectively reduced the amputation rate and adverse reactions for patients with DFU. Additionally, compared to the NPWT group, the combined treatment of PRP and UD with NPWT reduced the incidence of adverse reactions. However, no significant differences were observed among other treatment measures in terms of amputation rates and adverse reactions. The ranking results showed that the efficacy of PRP+NPWT and UD+NPWT in promoting ulcer healing, reducing ulcer area, shortening healing time, decreasing amputation rates and adverse reactions is superior to that of the alone PRP group, NPWT group, and UD group. Conversely, the SOC group demonstrates the least effective performance in all aspects.

Conclusion

Due to the particularity of the wound of DFU, the standard of care is not effective, but the new treatment scheme has a remarkable effect in many aspects. And the treatment of DFU is not a single choice, combined with a variety of methods often achieve better efficacy, and will not bring more adverse reactions.

Unlocking the potential of flavonoid-infused drug delivery systems for diabetic wound healing with a mechanistic exploration

Diabetes is one of the common endocrine disorders generally characterized by elevated levels of blood sugar. It can originate either from the inability of the pancreas to synthesize insulin, which is considered as an autoimmune disorder, or the reduced production of insulin, considered as insulin resistivity. A wound can be defined as a condition of damage to living tissues including skin, mucous membrane and other organs as well. Wounds get complicated with respect to time based on specific processes like diabetes mellitus, obesity and immunocompromised conditions. Proper growth and functionality of the epidermis gets sustained due to impaired diabetic wound healing which shows a sign of dysregulated wound healing process. In comparison with synthetic medications, phytochemicals like flavonoids, tannins, alkaloids and glycosides have gained enormous importance relying on their distinct potential to heal diabetic wounds. Flavonoids are one of the most promising and important groups of natural compounds which can be used to treat acute as well as chronic wounds. Flavonoids show excellent properties due to the presence of hydroxyl groups in their chemical structure, which makes this class of compounds different from others. Based on the novel principles of nanotechnology via utilizing suitable drug delivery systems, the delivery of bioactive constituents from plant source amplifies the wound-healing mechanism, minimizes complexities and enhances bioavailability. Hence, the encapsulation and applicability of flavonoids with an emphasis on mechanistic route and wound-healing therapeutics have been highlighted in the subsequent study with focus on multiple drug delivery systems.

The Combination of Chitosan-Based Biomaterial and Cellular Therapy for Successful Treatment of Diabetic Foot-Pilot Study

Diabetic foot ulceration is one of the most common complications in patients treated for diabetes mellitus. The presented pilot study describes the successful treatment of diabetic ulceration of the heel with ongoing osteomyelitis in a 39-year-old patient after using a combination of modified chitosan-based biomaterial in combination with autologous mesenchymal stem cells isolated from bone marrow and dermal fibroblasts. The isolated population of bone marrow mesenchymal stem cells fulfilled all of the attributes given by the International Society for Stem Cell Research, such as fibroblast-like morphology, the high expression of positive surface markers (CD29: 99.1 ± 0.4%; CD44: 99.8 ± 0.2% and CD90: 98.0 ± 0.6%) and the ability to undergo multilineage differentiation. Likewise, the population of dermal fibroblasts showed high positivity for the widely accepted markers collagen I, collagen III and vimentin, which was confirmed by immunocytochemical staining. Moreover, we were able to describe newly formed blood vessels shown by angio CT and almost complete closure of the skin defect after 8 months of the treatment.

The Research of a Large-Scale Analysis Platform for MNS Blood Group Identification Based on Long-Read Sequencing

The objective of this study was to devise a novel approach for determining MNS blood group utilizing long-read sequencing (LRS) and to identify intricate genome variations associated with this blood group system. In this study, a total of 60 blood samples were collected from randomly selected Chinese Han blood donors. The amplification of the full-length sequences of GYPA exon 2-7 (11 kb) and GYPB exon 2-6 (7 kb) was conducted on the blood samples obtained from these 60 donors. Subsequently, the sequencing of these amplified sequences was performed using the PacBio platform. The obtained sequencing data were then compared with the reference sequence of the human genome (GRCh38) utilizing the pbmm2 software, resulting in the acquisition of the haploid sequences of GYPA and GYPB. The serological typing prediction was conducted using the International Society of Blood Transfusion (ISBT) database, while the analysis of SNVs sites was performed using deepvariant v1.2.0 software and reference sequence alignment. A total of 60 samples yielded unambiguous high-quality haplotypes, which can serve as a standardized reference sequence for molecular biology typing of MNSs in the Chinese population. In a total of 60 serological samples, the LRS method successfully identified the M, N, S, and s blood group antigens by analyzing specific genetic variations (c.59, c.71, c.72 for GYPA, and c.143 for GYPB), which aligned with the results obtained through conventional serological techniques. 4 Mur samples that had been previously validated through serology and molecular biology were successfully confirmed, and complete haploid sequences were obtained. Notably, one of the Mur samples exhibited a novel breakpoint, GYP (B1-136-B ψ 137-212-A213-229-B230-366), thereby representing a newly identified subtype. Single molecule sequencing, which eliminates the necessity for PCR amplification, effectively encompasses GC and high repeat regions, enhancing accuracy in quantifying mutations with low abundance or frequency. By employing LRS analysis of the core region of GYPA and GYPB, diverse genotypes of MNS can be precisely and reliably identified in a single assay. This approach presents a comprehensive, expeditious, and precise novel method for the categorization and investigation of MNS blood group system.

Mesenchymal stem cell therapy in diabetic foot ulcer: An updated comprehensive review

Background

Diabetes has evolved into a worldwide public health issue. One of the most serious complications of diabetes is diabetic foot ulcer (DFU), which frequently creates a significant financial strain on patients and lowers their quality of life. Up until now, there has been no curative therapy for DFU, only symptomatic relief or an interruption in the disease's progression. Recent studies have focused attention on mesenchymal stem cells (MSCs), which provide innovative and potential treatment candidates for several illnesses as they can differentiate into various cell types. They are mostly extracted from the placenta, adipose tissue, umbilical cord (UC), and bone marrow (BM). Regardless of their origin, they show comparable features and small deviations. Our goal is to investigate MSCs' therapeutic effects, application obstacles, and patient benefit strategies for DFU therapy.

Methodology

A comprehensive search was conducted using specific keywords relating to DFU, MSCs, and connected topics in the databases of Medline, Scopus, Web of Science, and PubMed. The main focus of the selection criteria was on English-language literature that explored the relationship between DFU, MSCs, and related factors.

Results and Discussion

Numerous studies are being conducted and have demonstrated that MSCs can induce re-epithelialization and angiogenesis, decrease inflammation, contribute to immunological modulation, and subsequently promote DFU healing, making them a promising approach to treating DFU. This review article provides a general snapshot of DFU (including clinical presentation, risk factors and etiopathogenesis, and conventional treatment) and discusses the clinical progress of MSCs in the management of DFU, taking into consideration the side effects and challenges during the application of MSCs and how to overcome these challenges to achieve maximum benefits.

Conclusion

The incorporation of MSCs in the management of DFU highlights their potential as a feasible therapeutic strategy. Establishing a comprehensive understanding of the complex relationship between DFU pathophysiology, MSC therapies, and related obstacles is essential for optimizing therapy outcomes and maximizing patient benefits.

Research progress on and molecular mechanism of vacuum sealing drainage in the treatment of diabetic foot ulcers

Diabetic foot ulcers (DFUs) are common chronic wounds and a common complication of diabetes. The foot is the main site of diabetic ulcers, which involve small and medium-sized arteries, peripheral nerves, and microcirculation, among others. DFUs are prone to coinfections and affect many diabetic patients. In recent years, interdisciplinary research combining medicine and material science has been increasing and has achieved significant clinical therapeutic effects, and the application of vacuum sealing drainage (VSD) in the treatment of DFUs is a typical representative of this progress, but the mechanism of action remains unclear. In this review, we integrated bioinformatics and literature and found that ferroptosis is an important signaling pathway through which VSD promotes the healing of DFUs and that System Xc-GSH-GPX4 and NAD(P)H-CoQ10-FSP1 are important axes in this signaling pathway, and we speculate that VSD is most likely to inhibit ferroptosis to promote DFU healing through the above axes. In addition, we found that some classical pathways, such as the TNF, NF-κB, and Wnt/β-catenin pathways, are also involved in the VSD-mediated promotion of DFU healing. We also compiled and reviewed the progress from clinical studies on VSD, and this information provides a reference for the study of VSD in the treatment of DFUs.

Evaluation of a new low-cost negative pressure wound therapy in the treatment of diabetic foot ulcers

OBJECTIVE

To investigate the effectiveness of a new and low-cost negative pressure wound therapy (LC-NPWT) in the treatment of diabetic foot ulcers (DFUs).

METHOD

In this retrospective cohort study, patients from our inpatient clinic with Wagner grade 3 DFUs were given LC-NPWT or conventional wound dressings. The primary outcome was the wound healing rates. Complete wound healing, defined as complete re-epithelialisation of the wound, was recorded during the two months of follow-up. The definition of complete epidermis of the wound was that the skin was closed (100% re-epithelialisation), with no drainage or dressing. The secondary outcomes were the number of inpatient days and surgical procedures, and outcomes after hospital discharge. The wound score from the Bates-Jensen wound assessment tool and the levels of the inflammation factors procalcitonin (PCT), C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) were compared between the two groups. The Kaplan-Meier survival estimate was used to examine the cumulative wound healing rate.

RESULTS

The study cohort comprised 41 patients. The two-month wound healing rate was higher in patients in the LC-NPWT group than in the control group (15/21 (71.4%) versus 8/20 (40.0%), respectively; p=0.043). At the end of the two-month follow-up period, the cumulative wound healing rate was higher in the LC-NPWT group than in the control group (p=0.032). Patients in the LC-NPWT group had fewer inpatient days (19.3±3.84 versus 25.05±4.81; p<0.001) and shorter duration of antibiotic use (32.14±3.89 days versus 36.10±5.80 days; p=0.014) than those who received conventional wound dressings. There were significant improvements in mean wound score between the LC-NPWT group and the control group (p<0.001). After one week of treatment, the blood levels of PCT (0.03±0.30ng/ml versus 0.07±0.08ng/ml; p=0.039), CRP (14.55±13.40mg/l versus 24.71±18.10mg/l; p=0.047) and ESR (42.05±29.29mm/h versus 61.65±22.42mm/h; p=0.021) were lower in patients who received LC-NPWT than those who received conventional wound dressings.

CONCLUSION

LC-NPWT is effective in the treatment of DFUs and provides a cheaper alternative for patients with DFUs that could potentially alleviate the economic distress these patients endure.

The impact of manual vacuum-assisted closure technique in wound healing: a case report

BACKGROUND

Diabetic ulcers are complex wounds that require specialized care. Proper wound care is crucial to prevent amputation, and one effective treatment option is negative pressure wound therapy. However, the cost of negative pressure wound therapy can often be a barrier, making it difficult for caregivers and families to access.

AIM

This study aims to develop an alternative system, called the manual vacuum-assisted closure technique, using a 50 cc syringe pump with a pressure value of 93.33 mmHg, to examine the impact of the manual vacuum-assisted closure technique on the continuum of wound status in diabetic ulcers.

CASE PRESENTATION

A 56-year-old Minangnese man, with a 15-year history of diabetes mellitus and a family history of the disease, presented with a grade IV diabetic ulcer on the dorsal pedis dextra following a postoperative debridement. The wound measured 48 cm2 and had an ankle-brachial index value of 1.0 mmHg. The ulcer originated from being pierced by a nail. Previous treatment involved surgical debridement in early January, followed by twice-daily wound care using gauze and 0.9% NaCl, which showed no improvement. Consequently, the wound worsened and became more painful. The patient also had a history of smoking, which he only quit earlier this year. The wound was assessed using the Bates-Jensen Wound Assessment Tool over a period of 21 days.

CONCLUSION

After daily manual vacuum-assisted closure technique wound treatment for 21 days in diabetic ulcers, there was a noticeable decrease in the Bates-Jensen Wound Assessment Tool scores. Specifically, on day 5, the score was 38; on day 14, the score was 30; and on day 21, the score was 24. The use of the manual vacuum-assisted closure technique in wound treatment demonstrated significant improvements in diabetic ulcers.

Enhancing angiogenesis: Innovative drug delivery systems to facilitate diabetic wound healing

Diabetic wounds (DW) constitute a substantial burden on global healthcare owing to their widespread occurrence as a complication of diabetes. Angiogenesis, a crucial process, plays a pivotal role in tissue recovery by supplying essential oxygen and nutrients to the injury site. Unfortunately, in diabetes mellitus, various factors disrupt angiogenesis, hindering wound healing. While biomaterials designed to enhance angiogenesis hold promise for the treatment of DWs, there is an urgent need for more in-depth investigations to fully unlock their potential in clinical management. In this review, we explore the intricate mechanisms of angiogenesis that are crucial for DW recovery. We introduce a rational design for angiogenesis-enhancing drug delivery systems (DDS) and provide a comprehensive summary and discussion of diverse biomaterials that enhance angiogenesis for facilitating DW healing. Lastly, we address emerging challenges and prospects in angiogenesis-enhancing DDS for facilitating DW healing, aiming to offer a comprehensive understanding of this critical healthcare issue and potential solutions.

Relation Between Tissue Iron Content and Polarization of Macrophages in Diabetic Ulcer and the Transitional Zone of Diabetic Ulcers with Major Amputation

Most diabetic lower-limb amputations probably result from combinations of contributing causes rather than from unitary causes. Iron-induced damage might modulate the development of chronic diabetes complications. In this study, the relationship between tissue iron levels and polarization of macrophages in induction of angiogenesis was investigated in diabetic ulcer samples and the transitional zone of diabetic ulcers. Patients with diabetic ulcers who underwent amputation were included. The transitional zone of diabetic ulcers, from the same diabetic patients, was used as a control group. After tissue preparation, Perls Prussian blue staining and immunohistochemistry for CD11c, CD163, and CD68 markers were done. Vascular endothelial growth factor (VEGF), hypoxia-inducible factor (HIF), Tie2, and protein kinase B (also known as AKT) transcription of genes were measured by real-time polymerase chain reaction. For statistical analysis, we used independent samples t-test or its nonparametric equivalents, Mann-Whitney U test was used for quantitative variables, and chi-square (or Fisher's exact test) for qualitative variables. According to the results, the ratio of M2 to M1 macrophages was decreased in ulcers tissue compared to the transitional zone of diabetic ulcers. The expression of angiogenesis-related genes was increased due to hypoxia induction such as HIF and VEGF in ulcer tissue (P < .0001), but the expression of vascular stability-related genes such as Tie2 was decreased (P < .0001).In amputated diabetic ulcers, the polarization of macrophages is toward the classic type, but no connection was found in terms of tissue iron and help in the polarization of macrophages.

An in-vitro evaluation of antifungal, anti-lungcancer (A549), and anti-hyperglycemic activities potential of Andrographis paniculata (Burm. f.) flower extract

The medical plant research has received more attention among researchers especially after the Covid-19 pandemic. This research performed to evaluate the antifungal, anti-lung cancer (A549), and anti-hyperglycemic activities of aqueous extract of Andrographis paniculata flower. Interestingly, A. paniculata flower aqueous extract contains pharmaceutically valuable phytochemicals such as alkaloid, phenolics, terpenoids, tannins, flavonoids, and protein. It also showed fine antifungal activity against test fungal pathogens in the following order as: Aspergillus niger > Fusarium solani > Trichoderma harzianum > A. parasiticus > P. expansum > Penicillium janthinellum with lowest MIC values as ranged from 100 to 300 μg mL-1. Interestingly, this aqueous extract also showed considerable anti-lung cancer activity, evidenced by dose and time dependent lung cancer cell line (A549) growth/proliferation inhibition/cytotoxicity activity (65%) at 300 μg mL-1 concentration. This can be achieved by plant extract through inducing the secretion of apoptosis related proteins such as TNF α, IFN-γ, and ınterleukin 2 leads to apoptosis in A549 cells. It also showed fine anti-diabetic activity by inhibiting α -amylase (58.41%) than α-glucosidase (54.74%) at 200 μg mL-1 concentration. The UV as well as FTIR results demonstrated that the aqueous extract of A. paniculata flower contains pharmaceutically valuable bioactive compounds, which may be responsible for the wide range of biomedical applications.

Temperature-sensitive hydrogel dressing loaded with nicotinamide mononucleotide accelerating wound healing in diabetic mice

Diabetic foot ulcers, a common complication of diabetes mellitus, significantly impact patients' quality of life and impose a substantial economic burden on healthcare systems. However, the currently used treatments are associated with various challenges and the traditionally used dressings lack functional efficacy. Oxidative stress is believed to play a vital role in diabetic wound healing. Therefore, nicotinamide mononucleotide (NMN), which is known for its antioxidant properties, offers the potential to accelerate the wound-healing process. Here, a thermosensitive composite hydrogel was synthesized by mixing Pluronic F127 and Pluronic F68 with an antibacterial component chitosan. The hydrogel exhibited favorable properties including a stable structure, appropriate solid-liquid phase change, loose porosity, slow-release, antibacterial properties, and biocompatibility. In vitro experiments demonstrated that the NMN-loaded temperature-sensitive hydrogel effectively promoted cell proliferation, migration, and angiogenesis and exhibited antioxidant activity. In diabetic thickness skin defect models, NMN-loaded temperature-sensitive hydrogel treatment significantly accelerated wound healing by promoting collagen synthesis, angiogenesis, and increased expression of vascular endothelial growth factor and transforming growth factor- β1. In summary, NMN-loaded temperature-sensitive hydrogel can promote diabetic wound healing in a simple, economical, effective, and safe manner, with potential application in treating diabetic wounds.

Role of Autologous Fat Transplantation Combined with Negative-Pressure Wound Therapy in Treating Rat Diabetic Wounds

BACKGROUND

Negative-pressure wound therapy (NPWT) and autologous fat transplantation (AFT) are two clinical modalities for plastic and reconstructive surgery. At present, there are few reports on the combination of these two methods in treating diabetic wounds. This study aimed to explore the effect of this combined therapy on diabetic wound healing.

METHODS

Full-thickness dorsal cutaneous wounds in rats with streptozotocin-induced diabetes were treated with either NPWT, AFT, or combined therapy. Rats covered with commercial dressings served as the control group. Macroscopic healing kinetics were examined. The levels of inflammation-related factors, such as interleukin-1β (IL-1β), interleukin-6 (IL-6), monocyte chemoattractant protein-1, arginase-1, and inducible nitric oxide synthase (iNOS) and angiogenesis-related factors such as vascular endothelial growth factor, were measured in the wound tissues on days 3, 7, and 14; immunohistochemical staining for arginase-1, iNOS, and CD31 was performed on days 3, 7, and 14. The length of reepithelialization was investigated on day 14.

RESULTS

The combined therapy promoted faster wound healing than the other treatments. The expression levels of the proinflammatory factors IL-1β, IL-6, monocyte chemoattractant protein-1 (MCP-1), and iNOS were reduced, and arginase-1 expression was increased compared with those in the other groups. The expression levels of vascular endothelial growth factor and CD31 in the NPWT-combined-with-AFT group were significantly higher than those in the other groups. Reepithelialization was faster in the NPWT-combined-with-AFT group (by day 14) than in the other groups.

CONCLUSION

Combining NPWT and AFT can enhance diabetic wound healing by improving wound inflammation and increasing wound vascularization.

CLINICAL RELEVANCE STATEMENT

The authors designed a randomized controlled trial of diabetic rats to confirm that NPWT can enhance the vascularization and improve inflammation of the diabetic wound after the autologous fat transplantation treatment. This article may provide a new idea for treating diabetic wounds.

Diabetic foot ulcer: A comprehensive review of pathophysiology and management modalities

Diabetic foot ulcer (DFU) is a debilitating and severe manifestation of uncontrolled and prolonged diabetes that presents as ulceration, usually located on the plantar aspect of the foot. Approximately 15% of individuals with diabetes will eventually develop DFU, and 14%-24% of them will require amputation of the ulcerated foot due to bone infection or other ulcer-related complications. The pathologic mechanisms underlying DFU are comprise a triad: Neuropathy, vascular insufficiency, and secondary infection due to trauma of the foot. Standard local and invasive care along with novel approaches like stem cell therapy pave the way to reduce morbidity, decrease amputations, and prevent mortality from DFU. In this manuscript, we review the current literature with focus on the pathophysiology, preventive options, and definitive management of DFU.

Tissue Engineering-Based Strategies for Diabetic Foot Ulcer Management

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

Future Directions in Research in Transcriptomics in the Healing of Diabetic Foot Ulcers

Diabetic foot ulcers are a health crisis that affect millions of individuals worldwide. Current standard of care involves diligent wound care with adjunctive antibiotics and surgical debridement. However, despite this, the majority will still become infected and fail to heal. Recent efforts using bioengineered skin initially appeared promising, but randomized clinical trials have disappointed. Scientists have now begun to understand that the normal wound healing physiology does not apply to diabetic foot ulcers as they maintain a chronic state of inflammation and fail to progress in a linear pathway. Using transcriptomics, research over the past decade has started identifying master genes and protein pathways that are dysregulated in patients with diabetes. This review paper discusses those genes involved and how novel advancements are using this information to create new biologically based compounds to accelerate wound healing in patients with diabetic foot ulcers.

Diabetic foot ulcer: Challenges and future

Diabetic foot ulcers (DFUs) have become one of the important causes of mortality and morbidity in patients with diabetes, and they are also a common cause of hospitalization, which places a heavy burden on patients and society. The prevention and treatment of DFUs requires multidisciplinary management. By controlling various risk factors, such as blood glucose levels, blood pressure, lipid levels and smoking cessation, local management of DFUs should be strengthened, such as debridement, dressing, revascularization, stem cell decompression and oxygen therapy. If necessary, systemic anti-infection treatment should be administered. We reviewed the progress in the clinical practice of treating DFUs in recent years, such as revascularization, wound repair, offloading, stem cell transplantation, and anti-infection treatment. We also summarized and prospectively analyzed some new technologies and measurements used in the treatment of DFUs and noted the future challenges and directions for the development of DFU treatments.

Evolving spectrum of diabetic wound: Mechanistic insights and therapeutic targets

Diabetes mellitus is a chronic metabolic disorder resulting in an increased blood glucose level and prolonged hyperglycemia, causes long term health conse-quences. Chronic wound is frequently occurring in diabetes patients due to compromised wound healing capability. Management of wounds in diabetic patients remains a clinical challenge despite many advancements in the field of science and technology. Increasing evidence indicates that alteration of the biochemical milieu resulting from alteration in inflammatory cytokines and matrix metalloproteinase, decrease in fibroblast and keratinocyte functioning, neuropathy, altered leukocyte functioning, infection, etc., plays a significant role in impaired wound healing in diabetic people. Apart from the current pharmacotherapy, different other approaches like the use of conventional drugs, antidiabetic medication, antibiotics, debridement, offloading, platelet-rich plasma, growth factor, oxygen therapy, negative pressure wound therapy, low-level laser, extracorporeal shock wave bioengineered substitute can be considered in the management of diabetic wounds. Drugs/therapeutic strategy that induce angiogenesis and collagen synthesis, inhibition of MMPs, reduction of oxidative stress, controlling hyperglycemia, increase growth factors, regulate inflammatory cytokines, cause NO induction, induce fibroblast and keratinocyte proliferation, control microbial infections are considered important in controlling diabetic wound. Further, medicinal plants and/or phytoconstituents also offer a viable alternative in the treatment of diabetic wound. The focus of the present review is to highlight the molecular and cellular mechanisms, and discuss the drug targets and treatment strategies involved in the diabetic wound.

Effect of Micropower Vacuum Dressing on Promoting Wound Healing in Patients with I-II Diabetic Foot

Objective

Discuss the effectiveness and value of micropower vacuum dressing (MVD) in promoting the healing of I-II grades diabetic foot wounds.

Methods

Sixty patients diagnosed with diabetic foot ulcers and Wagner grades I-II were selected and randomly divided into the control group and experimental group, with 30 cases in each group. The control group was covered with conventional treatments and petrolatum gauze dressings, and the experimental group was treated with MVD on the basis of conventional reatments. The therapeutic effects of the two groups were observed, including healing rate, ulcer area reduction rate, ulcer healing time, dressing change times, ulcer recurrence rate, adverse events, and so on.

Results

The healing rate (100%) of the experimental group was higher than that of the control group (56.7%); the wound reduction rate was higher than that of the control group (P < 0.05); the healing time, the number of dressing changes, and the 1-month recurrence rate were all low in the control group (P < 0.05). The incidence of adverse reactions in the experimental group (6.7%) was lower than that in the control group (46.7%) (P < 0.05).

Conclusion

MVD has significant effects in the treatment of I-II grades diabetic foot wounds and has few adverse reactions. It is an effective new method that can promote the growth of granulation tissue and epithelium and promote wound healing.

Notoginsenoside R1 Facilitated Wound Healing in High-Fat Diet/Streptozotocin-Induced Diabetic Rats

Diabetic ulcers bring about high morbidity and mortality in patients and cause a great economic burden to society as a whole. Since existing treatments cannot fulfil patient requirements, it is urgent to find effective therapies. In this study, the wound healing effect of topical notoginsenoside R1 (NR1) treatment on diabetic full-thickness wounds in type II diabetes mellitus (T2DM) was induced by the combination of a high-fat diet and streptozotocin (STZ) injection. NR1 significantly increased the wound closure rate, enhanced extracellular matrix (ECM) secretion, promoted collagen growth, increased platelet endothelial cell adhesion molecule-1 (CD31) expression, and decreased cleaved caspase-3 expression. RNA-Seq analysis identified ECM remodeling and inflammation as critical biological processes and Timp1 and Mmp3 as important targets in NR1-mediated wound healing. Further experiments showed that NR1-treated wounds demonstrated higher expression of tissue inhibitor of metalloproteinase 1 (TIMP1) and transforming growth factor-β1 (TGFβ1) and lower expression of matrix metallopeptidase 9 (MMP9), matrix metallopeptidase 3 (MMP3), interleukin-1β (IL-1β), and interleukin-6 (IL-6) than diabetic wounds. These investigations promote the understanding of the mechanism of NR1-mediated diabetic wound healing and provide a promising therapeutic drug to enhance diabetic wound healing.

Consensus on the health education of home-based negative pressure wound therapy for patients with chronic wounds: a modified Delphi study

Background

The study aimed to develop consensus on the components of health education of home-based negative pressure wound therapy (NPWT) for patients with chronic wounds.

Methods

A Delphi method was used to achieve consensus on the components of health education and 75% agreement and coefficient of variation (CV) <0.25 were used as cutoff. Sixteen experts were recruited purposefully to finish this study.

Results

Two rounds of consultation were implemented. Consensus was achieved on 36 of the 42 statements. The final agreed list of statements represented three domains: health education before carrying out home-based NPWT, health education for the treatment day of NPWT at hospital and health education for NPWT at home.

Conclusions

This study was the first attempt to develop consensus on the comprehensive components of health education of home-based NPWT for patients with chronic wounds. According to the established framework and components of health education, wound professionals can safely and effectively implement health education of home-based NPWT for patients with chronic wounds and improve their self-care ability and treatment experience at home.

Assessment of nursing and midwifery students’ knowledge of treatment of diabetic foot syndrome using Lucilia servicata larvae

Background. Diabetes mellitus is one of the most common chronic diseases, and in recent years its prevalence has been systematically increasing. Untreated or ineffectively treated diabetes leads to the development of many complications. Among these that can significantly affect the quality of life is diabetic foot syndrome (DFS). Larvotherapy is a therapeutic method of treating wounds arising during the course of DFS. Aim of the study. The main objective of this study was to assess the level of knowledge of nursing and midwifery students on the treatment of DFS using Lucilia sericata larvae. Material and Methods. This study is a cross-sectional, observational study in which 202 nursing and midwifery students of Opole University were surveyed. The study was conducted online between June and November 2020, using a questionnaire developed by the authors. Results. The analysis showed considerable variation in the level of students' knowledge of treatment techniques for DFS. Those with the highest level of knowledge represented 39.15% (n=79), the average level of knowledge was represented by 28.2% (n=57), and the lowest level of knowledge was represented by 32.7% (n=66) of students. Regarding biosurgery in general, the highest level of knowledge about biosurgery was represented by 48.0% (n=97) of students. Nursing students had a higher level of knowledge than midwifery students regarding DFS treatment methods (p=0.001). There was no difference in the level of knowledge about biosurgery between nursing and midwifery students (p=0.503). Conclusions. The research presented in this study indicates that nursing and midwifery students have insufficient knowledge of DFS treatment methods and biosurgery. Nursing students are more likely than midwifery students to derive knowledge of DFS treatment methods from their studies and the literature. Education on treatment methods and techniques for DFS should be increased among students. Students' knowledge can be increased by classes in the course of their education and meetings with professionals.

Comprehensive analysis of lncRNA and miRNA expression profiles and ceRNA network construction in negative pressure wound therapy

Background

This study aims to explore the molecular mechanism of negative pressure wound therapy (NPWT) at the transcriptome level through whole transcriptome sequencing and biometric analysis.

Methods

A rat skin defect model was constructed and randomly divided into a NPWT group and a gauze group. The tissue in the center of the wound was used for whole transcriptome sequencing, and differentially expressed messenger RNAs (DEmRNAs), long noncoding RNAs (DElncRNAs), and microRNAs (DEmiRNAs) were identified between the two groups. Quantitative real time-polymerase chain reaction (qRT-PCR) analysis was used to verify the sequencing results. Functional enrichment analysis, pathway analysis, and protein-protein interaction (PPI) network analysis of DEmRNAs were conducted. Through bioinformatics analysis, a lncRNA-associated competing endogenous RNA (ceRNA) network was identified and constructed.

Results

We detected 896 DEmRNAs, 1,471 DElncRNAs, and 20 DEmiRNAs between the two groups. qRT-PCR verified the sequencing results. Functional analysis showed that DEmRNAs were mainly enriched in immune system processes and the Notch signaling pathway. Protein tyrosine phosphatase receptor type C (PTPRC) and signal transducer and activator of transcription 1 (STAT1) were the central hub nodes in the PPI analysis. The ceRNA network contained 11 mRNAs, 15 lncRNAs, and 4 miRNAs.

Conclusions

We identified several DEmRNAs, DElncRNAs, and DEmiRNAs between the NPWT treatment group and the control group. These findings may provide new insights into the pathophysiological mechanism of NPWT and wound healing.

Downregulation of hsa-miR-203 in peripheral blood and wound margin tissue by negative pressure wound therapy contributes to wound healing of diabetic foot ulcers

Negative pressure wound therapy (NPWT) has been widely used in the treatment of chronic wounds, including diabetic foot ulcers (DFU) as the severe manifestation of diabetic foot. Hsa-miR-203 is proven to be correlated with the severity of DFU. To investigate whether NPWT influences hsa-miR-203 levels in persons with DFU, we detected hsa-miR-203 levels in peripheral plasma and wound margin tissue from the following patients: type 2 diabetic (T2D) patients with DFU (DFU group), T2D patients without DFU (NDFU group), patients with chronic skin ulcer and normal glucose tolerance (SUC group), and healthy volunteers with normal glucose tolerance (NC group). All patients in SUC group received NPWT. As contrast, some of patients in DFU group received NPWT (NPWT group) while others chose routine dressing therapy (non-NPWT group). In vitro experiments were also performed to determine influences of negative pressure on cell proliferation and migration of HaCaT cells (human keratinocytes). Results showed that before NPWT, levels of hsa-miR-203 in peripheral plasma (P-miR-203) and wound margin tissue (T-miR-203) of DFU group were obviously increased compared to SUC group while expression of P-miR-203 decreased in NDFU group compared with NC group. After NPWT, levels of P-miR-203 and T-miR-203 in DFU and SUC group were significantly lower than before. Changes of P-miR-203 and T-miR-203 after NPWT were positively correlated with 4-week ulcer healing rate in NPWT and SUC group. In vitro, negative pressure lowered the expression of hsa-miR-203, enhancing cell proliferation and migration in HaCaT cells via up-regulation of p63 protein. Meanwhile, the effects of negative pressure on cells were remarkable reduced by high-glucose intervention. Our study suggests that NPWT promotes DFU healing by reducing the expression of hsa-miR-203 in peripheral blood and wound tissue. The changes of hsa-miR-203 in peripheral blood and wound tissue may be related to the therapeutic effect of NPWT.

Proteomics changes after negative pressure wound therapy in diabetic foot ulcers

Label-free quantitative mass spectrometry was used to analyze the differences in the granulation tissue protein expression profiles of patients with diabetic foot ulcers (DFUs) before and after negative-pressure wound therapy (NPWT) to understand how NPWT promotes the healing of diabetic foot wounds. A total of three patients with DFUs hospitalized for Wagner grade 3 were enrolled. The patients received NPWT for one week. The granulation tissue samples of the patients prior to and following NPWT for one week were collected. The protein expression profiles were analyzed with label-free quantitative mass spectrometry and the differentially expressed proteins (DEPs) in the DFU patients prior to and following NPWT for one week were identified. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were conducted to annotate the DEPs and DEP-associated signaling pathways. Western blotting and ELISA were performed to validate the results. By comparing the differences in the protein profiles of granulation tissue samples prior to and following NPWT for one week, 36 proteins with significant differences were identified (P<0.05); 33 of these proteins were upregulated and three proteins were downregulated. NPWT altered proteins mainly associated with antioxidation and detoxification, the cytoskeleton, regulation of the inflammatory response, complement and coagulation cascades and lipid metabolism. The functional validation of the DEPs demonstrated that the levels of cathepsin S in peripheral blood and granulation tissue were significantly lower than those prior to NPWT (P<0.05), while the levels of protein S isoform 1, inter α-trypsin inhibitor heavy chain H4 and peroxiredoxin-2 in peripheral blood and granulation tissue were significantly higher than those prior to NPWT (P<0.05). The present study identified multiple novel proteins altered by NPWT and laid a foundation for further studies investigating the mechanism of action of NPWT.

Microplasma Treatment versus Negative Pressure Therapy for Promoting Wound Healing in Diabetic Mice

The delayed healing response of diabetic wounds is a major challenge for treatment. Negative pressure wound therapy (NPWT) has been widely used to treat chronic wounds. However, it usually requires a long treatment time and results in directional growth of wound healing skin tissue. We investigated whether nonthermal microplasma (MP) treatment can promote the healing of skin wounds in diabetic mice. Splint excision wounds were created on diabetic mice, and various wound healing parameters were compared among MP treatment, NPWT, and control groups. Quantitative analysis of the re-epithelialization percentage by detecting Ki67 and DSG1 expression in the extending epidermal tongue (EET) of the wound area and the epidermal proliferation index (EPI) was subsequently performed. Both treatments promoted wound healing by enhancing wound closure kinetics and wound bed blood flow; this was confirmed through histological analysis and optical coherence tomography. Both treatments also increased Ki67 and DSG1 expression in the EET of the wound area and the EPI to enhance re-epithelialization. Increased Smad2/3/4 mRNA expression was observed in the epidermis layer of wounds, particularly after MP treatment. The results suggest that the Smad-dependent transforming growth factor β signaling contributes to the enhancement of re-epithelialization after MP treatment with an appropriate exposure time. Overall, a short-term MP treatment (applied for 30 s twice a day) demonstrated comparable or better efficacy to conventional NPWT (applied for 4 h once a day) in promoting wound healing in diabetic mice. Thus, MP treatment exhibits promise for treating diabetic wounds clinically.

Human Exosomes Accelerate Cutaneous Wound Healing by Promoting Collagen Synthesis in a Diabetic Mice Model

Chronic wounds including diabetic foot ulcers are clinical emergencies that need careful management. Exosomes from human adipose-derived mesenchymal stem cells (hADSCs-Ex) are a new promising cell-free therapy for the regeneration of dermal wounds. We established a delayed wound healing model using diabetic female mice. A 1.5 cm² full-thickness cutaneous wound was made ventrally in 6-week-old db/db mice. After treatment with phosphate-buffered saline, recombinant human epidermal growth factor, hADSCs-CM, or hADSCs-Ex three times a day for 2 weeks, we measured wound healing closure rates and performed histological analysis. Human dermal fibroblasts (WS1) were evaluated by PKH26-Exo co-localization test, CCK-8 test, cell scratch test, and the transwell test, while the expression of matrix metalloproteinase-1 (MMP1), MMP3, Collagen I, and Collagen III were analyzed by quantitative real-time polymerase chain reaction (qRT-PCR) and western blot. Wound closure and re-epithelialization were accelerated by hADSCs-Ex. Besides, hADSCs-Ex enhanced skin collagen production, angiogenesis, cell proliferation, inhibited apoptosis, promoted skin barrier function repair, and reduced inflammation in skin lesions. Furthermore, negative regulation of MMP1 and MMP3 enhanced collagen synthesis wound healing-promoting effects of hADSCs-Ex. hADSCs-Ex treatment for diabetic wounds provided a novel cell-free therapeutic strategy.

Pre-Clinical Assessment of Single-Use Negative Pressure Wound Therapy During In Vivo Porcine Wound Healing

Objective: Traditional negative pressure wound therapy (tNPWT) systems can be large and cumbersome, limiting patient mobility and adversely affecting quality of life. PICO™, a no canister single-use system, offers a lightweight, portable alternative to tNPWT, with improved clinical performance. The aim of this study was to determine the potential mechanism(s) of action of single-use NPWT (sNPWT) versus tNPWT. Approach: sNPWT and tNPWT were applied to an in vivo porcine excisional wound model, following product use guidelines. Macroscopic, histological, and biochemical analyses were performed at defined healing time points to assess multiple aspects of the healing response. Results: Wounds treated with single-use negative pressure displayed greater wound closure and increased reepithelialization versus those treated with traditional negative pressure. The resulting granulation tissue was more advanced with fewer neutrophils, reduced inflammatory markers, more mature collagen, and no wound filler-associated foreign body reactions. Of note, single-use negative pressure therapy failed to induce wound edge epithelial hyperproliferation, while traditional negative pressure therapy compromised periwound skin, which remained inflamed with high transepidermal water loss; features not observed following single-use treatment. Innovation: Single-use negative pressure was identified to improve multiple aspects of healing versus traditional negative pressure treatment. Conclusion: This study provides important new insight into the differing mode of action of single-use versus traditional negative pressure and may go some way to explaining the improved clinical outcomes observed with single-use negative pressure therapy.

Consensus on the application of negative pressure wound therapy of diabetic foot wounds

Because China is becoming an aging society, the incidence of diabetes and diabetic foot have been increasing. Diabetic foot has become one of the main health-related killers due to its high disability and mortality rates. Negative pressure wound therapy (NPWT) is one of the most effective techniques for the treatment of diabetic foot wounds and great progress, both in terms of research and its clinical application, has been made in the last 20 years of its development. However, due to the complex pathogenesis and management of diabetic foot, irregular application of NPWT often leads to complications, such as infection, bleeding and necrosis, that seriously affect its treatment outcomes. In 2020, under the leadership of Burns, Trauma and Tissue Repair Committee of the Cross-Straits Medicine Exchange Association, the writing group for ‘Consensus on the application of negative pressure wound therapy of diabetic foot wounds’ was established with the participation of scholars from the specialized areas of burns, endocrinology, vascular surgery, orthopedics and wound repair. Drawing on evidence-based practice suggested by the latest clinical research, this consensus proposes the best clinical practice guidelines for the application and prognostic evaluation of NPWT for diabetic foot. The consensus aims to support the formation of standardized treatment schemes that clinicians can refer to when treating cases of diabetic foot.

Study Comparing Platform Wound Dressing, a Negative-Pressure Device without a Filler, with Three Conventional Negative-Pressure Wound Therapy Systems in the Treatment of Excisional and Incisional Wounds

BACKGROUND

All common negative-pressure wound therapy systems include a material, usually foam or gauze, at the wound/device interface. In this preclinical study, the authors have compared the effects on different wound healing parameters in the three most common negative-pressure wound therapy systems (i.e., V.A.C.VIA, PREVENA, and PICO) with a new device without foam or gauze (i.e., Platform Wound Dressing). A strong effort was made to avoid bias. The study was conducted under good laboratory practice conditions, with the presence of an independent observer.

METHODS

In pigs, three types of wounds were studied: full-thickness excisions, open incisions, and sutured closed incisions. Several macroscopic and microscopic parameters were studied. The pigs were euthanized on day 9 and all wounds were processed for histology and excisions for immunohistochemistry.

RESULTS

In general, the devices produced similar results, with only a few significant differences. In the excisions, the Platform Wound Dressing reduced wound area more than the V.A.C.VIA and the PICO. In the excisional wounds, reepithelialization was the same. In open incisions, PREVENA was better than the Platform Wound Dressing. Histologic examination showed that, in open incisions, there was less inflammation in the PREVENA-treated in comparison with the Platform Wound Dressing- and the PICO-treated wounds. Immunohistochemical analyses showed that the Platform Wound Dressing-treated excisions had significantly more blood vessels (von Willebrand factor) than the V.A.C.VIA-treated ones and that the PICO caused less T-cell activation (CD3) than the other two.

CONCLUSION

The devices-with foam, with gauze, or without either and just an embossed membrane-performed equally in general.

Biofilm-Innate Immune Interface: Contribution to Chronic Wound Formation

Delayed wound healing can cause significant issues for immobile and ageing individuals as well as those living with co-morbid conditions such as diabetes, cardiovascular disease, and cancer. These delays increase a patient’s risk for infection and, in severe cases, can result in the formation of chronic, non-healing ulcers (e.g., diabetic foot ulcers, surgical site infections, pressure ulcers and venous leg ulcers). Chronic wounds are very difficult and expensive to treat and there is an urgent need to develop more effective therapeutics that restore healing processes. Sustained innate immune activation and inflammation are common features observed across most chronic wound types. However, the factors driving this activation remain incompletely understood. Emerging evidence suggests that the composition and structure of the wound microbiome may play a central role in driving this dysregulated activation but the cellular and molecular mechanisms underlying these processes require further investigation. In this review, we will discuss the current literature on: 1) how bacterial populations and biofilms contribute to chronic wound formation, 2) the role of bacteria and biofilms in driving dysfunctional innate immune responses in chronic wounds, and 3) therapeutics currently available (or underdevelopment) that target bacteria-innate immune interactions to improve healing. We will also discuss potential issues in studying the complexity of immune-biofilm interactions in chronic wounds and explore future areas of investigation for the field.

The effect of low-level laser therapy on diabetic foot ulcers: A meta-analysis of randomised controlled trials

Our purpose was to perform a meta‐analysis to evaluate the effect of Low‐level laser therapy (LLLT) on diabetic foot ulcers (DFUs). The PubMed, Cochrane, Embase, Web of Science, Chinese BioMedical Literature Database (CBM), China National Knowledge Infrastructure (CNKI), VIP and Wanfang databases were searched systematically up to August 27, 2020. Studies that met the inclusion criteria were included in the analysis. A total of 13 randomised controlled trials (RCTs) and 413 patients were analysed. Compared with the control group, LLLT significantly increased the complete healing rate (risk ratio [RR] = 2.10, 95% confidence interval [CI] 1.56‐2.83, P < .00001), reduced the ulcer area (standardised mean difference [SMD] = 3.52, 95% CI 1.65‐5.38, P = .0002), and shortened the mean healing time (SMD = −1.40, 95% CI −1.90 to −0.91, P < .00001) of patients with DFUs. The quality of the evidence was very low according to the GRADE system. LLLT is a promising and effective adjuvant treatment to accelerate the healing of DFUs. Further evidence from larger samples and higher quality RCTs is needed to prove the effect of LLLT and to determine the most appropriate parameters for the healing of DFUs.

The Combined Use of a Non-Invasive Skin-Stretching Device and the Negative-Pressure Wound Therapy Technique in the Treatment of Postoperative Diabetic Foot

OBJECTIVE

The present study explored the effectiveness of using a non-invasive skin-stretching device (NSSD) combined with negative-pressure wound therapy (NPWT) for the postoperative wound repair of diabetic foot (DF) gangrene.

METHODS

The treatment group in this study involved 42 patients with Wagner grade 3-4 DF and undergone concomitant toe amputation or debridement, who were given NPWT combined with the use of a NSSD. The control group comprised 42 patients with similar trauma areas (±20%) that were matched at a ratio of 1:1. Following surgery, these patients received NPWT combined with the use of conventional dressings. A comparison was made of the postoperative wound healing rates and wound healing times of the two groups, with Kaplan-Meier survival analysis being used to compare the healing rate over time.

RESULTS

The three-month wound healing rate was higher in the treatment group than in the control group (38 of 42 [90.5%] vs 25 of 42 [59.5%], p = 0.002), and the wound healing time was shorter in the treatment group (44 days [95% CI 40.0-48.0]) than that in the control group (76 days [95% CI 63.0-89.0], p = 0.000). Taking the end of the final NPWT as the starting point, the comparison of wound healing time revealed that this period was shorter in the treatment group than that in the control group and the difference was statistically significant (11 days [95% CI 9.0-13.0] vs 42 days [95% CI 23.0-ND], p = 0.000).

CONCLUSION

The use of the NPWT technique combined with a NSSD can shorten the wound healing time and improve the wound healing rate of DF gangrene patients during the postoperative wound repair period.

Cellular benefits of single-use negative pressure wound therapy demonstrated in a novel ex vivo human skin wound model

Negative pressure wound therapy is a widely used treatment for chronic, nonhealing wounds. Surprisingly, few studies have systematically evaluated the cellular and molecular effects of negative pressure treatment on human skin. In addition, no study to date has directly compared recently available single-use negative pressure modalities to traditional negative pressure devices in a controlled setting. Here we developed a novel large-scale ex vivo human skin culture system to effectively evaluate the efficacy of two different negative pressure wound therapy modalities. Single-use and traditional negative pressure devices were applied to human ex vivo wounded skin sheets cultured over a period of 48 hours. Cellular tissue response to therapy was evaluated via a combination of histological analysis and transcriptional profiling, in samples collected from the wound edge, skin adjacent to the wound, and an extended skin region. Single-use negative pressure wound therapy caused less damage to wound edge tissue than traditional application, demonstrated by improved skin barrier, reduced dermal-epidermal junction disruption and a dampened damage response. Transcriptional profiling confirmed significantly less activation of multiple pro-inflammatory markers in wound edge skin treated with single-use vs traditional negative pressure therapy. These findings may help to explain the greater efficacy of sNPWT in the clinic, while offering a noninvasive system to develop improved NPWT-based therapies.

Stromal cell-derived factor loaded co-electrospun hydrophilic/hydrophobic bicomponent membranes for wound protection and healing

Chronic wounds are one of the key concerns for people with diabetes, frequently leading to infections and non-healing ulcers, and finally resulting in the amputation of limbs/organs. Stromal cell-derived factor 1 (SDF1) is a major chemokine that plays a significant role in tissue repair, vascularization, and wound healing. However, the long-term sustained delivery of SDF1 in a chronic wound environment is a great challenge. In order to facilitate the sustained release of SDF1 in diabetic wounds, it could be incorporated into wound-healing patches. Herein, we report the fabrication of a hydrophilic/hydrophobic bicomponent fiber-based membrane, where SDF1 was encapsulated inside hydrophilic fibers, and its applicability in wound healing. A co-electrospinning technique was employed for the fabrication of polymeric membranes where PVA and PCL form the hydrophilic and hydrophobic components, respectively. Morphological analysis of the developed membranes was conducted via scanning electron microscopy (SEM). The mechanical strength of the membranes was investigated via uniaxial tensile testing. The water uptake capacity of the membranes was also determined to understand the hydrophilicity and exudate uptake capacity of the membranes. To understand the proliferation, viability, and migration of skin-specific cells in the presence of SDF1-loaded membranes, in vitro cell culture experiments were carried out using fibroblasts, keratinocytes, and endothelial cells. The results showed the excellent porous morphology of the developed membranes with distinguishable differences in fiber diameters for the PVA and PCL fibers. The developed membranes possessed enough mechanical strength for use as wound-healing membranes. The co-electrospun membranes showed good exudate uptake capacity. The controlled and extended delivery of SDF1 from the developed membranes was observed over a prolonged period. The SDF1-loaded membranes showed enhanced cell proliferation, cell viability, and cell migration. These biocompatible and biodegradable SDF1-loaded bicomponent membranes with excellent exudate uptake capacity, and cell proliferation and cell migration properties can be exploited as a novel wound-dressing membrane aimed at chronic diabetic wounds.

Nonpharmacological Management of Diabetic Foot Ulcers: An Update

Diabetic foot ulcers (DFUs) are a common and serious complication of diabetes mellitus that is associated with increased morbidity and mortality, as well as substantial economic burden for the health care system. The standard of care for DFUs includes pressure off-loading, sharp debridement, and wound moisture balance, along with infection control and management of peripheral arterial disease. A variety of advanced modalities that target distinct pathophysiological aspects of impaired wound healing in diabetes are being studied as possible adjunct therapies for difficult to heal ulcers. These modalities include growth factors, stem cells, cultured fibroblasts and keratinocytes, bioengineered skin substitutes, acellular bioproducts, human amniotic membranes, oxygen therapy, negative pressure wound therapy, and energy therapies. Additionally, the use of advanced biomaterials and gene delivery systems is being investigated as a method of effective delivery of substances to the wound bed. In the present narrative review, we outline the latest advances in the nonpharmacological management of DFUs and summarize the efficacy of various standard and advanced treatment modalities.

Negative pressure wound therapy affects circulating plasma microRNAs in patients with diabetic foot ulceration

AIMS

Negative pressure wound therapy (NPWT) is commonly used in diabetic foot ulceration (DFU). The molecular mechanisms of NPWT action, particularly outside of the wound site, have not been described. We assessed NPWT's effect on circulating miRNA expression levels in type 2 diabetes (T2DM) patients with DFU.

METHODS

We examined 34 T2DM patients treated with either NPWT (n = 24) or standard therapy (ST, n = 10). The group assignment was based on clinical criteria and local practice. Next-generation sequencing-based microRNA expression was determined on the patient's plasma collected before therapy and after 8 days.

RESULTS

NPWT patients were similar to the ST group in terms of age, BMI, and HbA1c level; however, they differed by mean wound area (12.6 cm² vs. 1.1 cm² p = 0.0005). First, we analyzed the change of miRNA after NPWT or ST and observed an upregulation of let-7f-2 only in the NPWT group. Then, we analyzed the differential expression between NPWT and ST groups, looking at possible wound size effects. We found 12 differentially expressed miRNAs in pre-treatment comparison, including let-7f-2, while in post-treatment analysis we identified 28 miRNAs. The pathway enrichment analysis suggests that identified miRNAs may be involved in wound healing, particularly through angiogenesis.

CONCLUSION

We found initial evidence that NPWT in T2DM patients with DFU affects miRNA expression in plasma. Additionally, some differences in plasma miRNA expression may be related to wound size.

Silver nanoparticles: Advanced and promising technology in diabetic wound therapy

Wounds associated with diabetes mellitus are the most severe co-morbidities, which could be progressed to cause cell necrosis leading to amputation. Statistics on the recent status of the diabetic wounds revealed that the disease affects 15% of diabetic patients, where 20% of them undergo amputation of their limb. Conventional therapies are found to be ineffective due to changes in the molecular architecture of the injured area, urging novel deliveries for effective treatment. Therefore, recent researches are on the development of new and effective wound care materials. Literature is evident in providing potential tools in topical drug delivery for wound healing under the umbrella of nanotechnology, where nano-scaffolds and nanofibers have shown promising results. The nano-sized particles are also known to promote healing of wounds by facilitating proper movement through the healing phases. To date, focuses have been made on the efficacy of silver nanoparticles (AgNPs) in treating the diabetic wound, where these nanoparticles are known to exploit potential biological properties in producing anti-inflammatory and antibacterial activities. AgNPs are also known to activate cellular mechanisms towards the healing of chronic wounds; however, associated toxicities of AgNPs are of great concern. This review is an attempt to illustrate the use of AgNPs in wound healing to facilitate this delivery system in bringing into clinical applications for a superior dressing and treatment over wounds and ulcers in diabetes patients.

NPWT in diabetic foot wounds-a systematic review and meta-analysis of observational studies

PURPOSE

Negative-pressure wound therapy (NPWT) is an adjunct modality in diabetic foot ulcerations (DFUs). Randomized controlled trials (RCTs) have shown its advantage over standard approaches; however, data from observational studies remain scarce.We performed a systematic review of observational non-RCTs evaluating NPWT efficacy and safety in patients with DFU.

METHODS

Electronic databases were searched for observational studies involving NPWT. The results of single-arm studies were presented as percentages of patients with the outcome of interest. A meta-analysis of comparative studies provided point estimates of outcomes. Continuous outcomes were reported as either weighted or standardized mean differences and dichotomous data as relative risks (RR).

RESULTS

The search identified 16 relevant observational studies, 12 single-arm, and 4 comparative, reporting on a total of 18,449 patients with DFU, of whom 1882 were managed with NPWT. In the NPWT-treated patients, ulcers were larger (average size range 6.6-27.9 cm²), as compared with controls (≤3 cm²). The pooled results showed healing and major amputation in 51% and 5% of NPWT patients, respectively. The meta-analysis of comparative studies revealed lower risk of major amputation [RR = 0.23 (0.07; 0.80)] in NPWT-treated patients. The pooled results for healing rate and risk of any amputation were inconclusive due to large between-study heterogeneity. Overall, 6 deaths out of 158 patients were reported, none of them related to NPWT. Serious adverse events occurred in 6% of patients on NPWT.

CONCLUSIONS

This systematic review of observational studies provided supportive evidence that NWPT is an efficient and safe adjunct treatment in the management of DFUs.

Guidelines on the diagnosis and treatment of foot infection in persons with diabetes (IWGDF 2019 update)

The International Working Group on the Diabetic Foot (IWGDF) has published evidence-based guidelines on the prevention and management of diabetic foot disease since 1999. This guideline is on the diagnosis and treatment of foot infection in persons with diabetes and updates the 2015 IWGDF infection guideline. On the basis of patient, intervention, comparison, outcomes (PICOs) developed by the infection committee, in conjunction with internal and external reviewers and consultants, and on systematic reviews the committee conducted on the diagnosis of infection (new) and treatment of infection (updated from 2015), we offer 27 recommendations. These cover various aspects of diagnosing soft tissue and bone infection, including the classification scheme for diagnosing infection and its severity. Of note, we have updated this scheme for the first time since we developed it 15 years ago. We also review the microbiology of diabetic foot infections, including how to collect samples and to process them to identify causative pathogens. Finally, we discuss the approach to treating diabetic foot infections, including selecting appropriate empiric and definitive antimicrobial therapy for soft tissue and for bone infections, when and how to approach surgical treatment, and which adjunctive treatments we think are or are not useful for the infectious aspects of diabetic foot problems. For this version of the guideline, we also updated four tables and one figure from the 2016 guideline. We think that following the principles of diagnosing and treating diabetic foot infections outlined in this guideline can help clinicians to provide better care for these patients.

Effects of topical negative pressure therapy on perfusion and microcirculation of human skin

BACKGROUND

Topical negative pressure wound therapy (TNPWT) is one of the most frequently used techniques in wound treatment. But some of the underlying mechanisms still remain unclear. One possible explanation is an improved microcirculation by TNPWT.

OBJECTIVE

This study investigated the influence of TNPWT on microcirculation on intact skin in real-time.

METHODS

In healthy individuals, we performed a combined tissue - laser/photo - spectrometry technique to monitor changes of 4 different microcirculation parameters in real-time: The local blood flow, the capillary-venous oxygen saturation, the blood flow velocity and the relative amount of hemoglobin. We compared these parameters using two different protocols: a continuously (VAC ON 60/OFF 60) and discontinuously (VAC ON 30/OFF 60/ON 5) application.

RESULTS

Our results demonstrate a significant increase of all four measured parameters during the active TNPWT and the pressure free period. The comparison of two different protocols shows an advantage of the examined parameters using a discontinuous TNPWT application.

CONCLUSIONS

Our study demonstrated the changes of the microvascular tissue perfusion in intact human skin under the conditions of negative pressure and may thereby offer a broader understanding of mechanisms underlying the TNPWT.

DNA methylation analysis of negative pressure therapy effect in diabetic foot ulcers

OBJECTIVE

Negative pressure wound therapy (NPWT) has been used to treat diabetic foot ulcerations (DFUs). Its action on the molecular level, however, is only partially understood. Some earlier data suggested NPWT may be mediated through modification of local gene expression. As methylation is a key epigenetic regulatory mechanism of gene expression, we assessed the effect of NPWT on its profile in patients with type 2 diabetes (T2DM) and neuropathic non-infected DFUs.

METHODS

Of 36 included patients, 23 were assigned to NPWT and 13 to standard therapy. Due to ethical concerns, the assignment was non-randomized and based on wound characteristics. Tissue samples were obtained before and 8 ± 1 days after therapy initiation. DNA methylation patterns were checked by Illumina Methylation EPIC kit.

RESULTS

In terms of clinical characteristics, the groups presented typical features of T2DM; however, the NPWT group had significantly greater wound area: 16.8 cm2 vs 1.4 cm2 (P = 0.0003). Initially only one region at chromosome 5 was differentially methylated. After treatment, 57 differentially methylated genes were found, mainly located on chromosomes 6 (chr6p21) and 20 (chr20p13); they were associated with DNA repair and autocrine signaling via retinoic acid receptor. We performed differential analyses pre treatment and post treatment. The analysis revealed 426 differentially methylated regions in the NPWT group, but none in the control group. The enrichment analysis showed 11 processes significantly associated with NPWT, of which 4 were linked with complement system activation. All but one were hypermethylated after NPWT.

CONCLUSION

The NPWT effect on DFUs may be mediated through epigenetic changes resulting in the inhibition of complement system activation.

CTGF Loaded Electrospun Dual Porous Core-Shell Membrane For Diabetic Wound Healing

PURPOSE

Impairment of wound healing is a major issue in type-2 diabetes that often causes chronic infections, eventually leading to limb and/or organ amputation. Connective tissue growth factor (CTGF) is a signaling molecule with several roles in tissue repair and regeneration including promoting cell adhesion, cell migration, cell proliferation and angiogenesis. Incorporation of CTGF in a biodegradable core-shell fiber to facilitate its sustained release is a novel approach to promote angiogenesis, cell migration and facilitate wound healing. In this paper, we report the development of CTGF encapsulated electrospun dual porous PLA-PVA core-shell fiber based membranes for diabetic wound healing applications.

METHODS

The membranes were fabricated by a core-shell electrospinning technique. CTGF was entrapped within the PVA core which was coated by a thin layer of PLA. The developed membranes were characterized by techniques such as Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR) and X-Ray Diffraction (XRD) analysis. In vitro cell culture studies using fibroblasts, keratinocytes and endothelial cells were performed to understand the effect of CTGF loaded membranes on cell proliferation, cell viability and cell migration. A chicken chorioallantoic membrane (CAM) assay was performed to determine the angiogenic potential of the membranes.

RESULTS

Results showed that the developed membranes were highly porous in morphology with secondary pore formation on the surface of individual fibers. In vitro cell culture studies demonstrated that CTGF loaded core-shell membranes improved cell viability, cell proliferation and cell migration. A sustained release of CTGF from the core-shell fibers was observed for an extended time period. Moreover, the CAM assay showed that core-shell membranes incorporated with CTGF can enhance angiogenesis.

CONCLUSION

Owing to the excellent cell proliferation, migration and angiogenic potential of CTGF loaded core-shell PLA-PVA fibrous membranes, they can be used as an excellent wound dressing membrane for treating diabetic wounds and other chronic ulcers.

Effects of Negative Pressure Wound Therapy on Levels of Angiopoetin-2 and Other Selected Circulating Signaling Molecules in Patients with Diabetic Foot Ulcer

BACKGROUND AND AIMS

Diabetic foot ulcers (DFUs) are linked to amputations and premature deaths. Negative pressure wound therapy (NPWT) has been used for DFUs. The mechanism of NPWT's action may be associated with its influence on circulating molecules. We assessed NPWT's effect on the plasma levels of angiopoietin-2 (Ang2), a key regulator of angiogenesis, and its microvesicular receptors (Tie2) as well as the microvesicles (MVs) themselves in DFU patients.

MATERIALS AND METHODS

We included 69 patients with type 2 diabetes mellitus (T2DM) and neuropathic, noninfected DFUs-49 were treated with NPWT and 20 were treated with standard therapy (ST). Assigning patients to the NPWT group was not random but based on DFU characteristics, especially wound area. Ang2 was measured by ELISA in the entire group, while in a subgroup of 19 individuals on NPWT and 10 on ST, flow cytometry was used to measure Tie2+ and the corresponding isotype control (Iso+) and annexin V (AnnV+) as well as total MVs. Measurements were performed at the beginning and after 8 ± 1 days of therapy.

RESULTS

Treatment groups were similar for basic characteristics but differed by their median DFU areas (10.3 (4.2-18.9) vs. 1.3 (0.9-3.4) cm2, p = 0.0001). At day 0, no difference was observed in Ang2 levels, total MVs, MV Tie+, and MV AnnV+ between the groups. Ang2 decreased after 8 days in the NPWT group, unlike in the ST group (3.54 (2.40-5.40) vs. 3.32 (2.33-4.61), p = 0.02, and 3.19 ± 1.11 vs. 3.19 ± 1.29 ng/mL, p = 0.98, respectively). No other parameters were identified that may have been influenced by the NPWT treatment.

CONCLUSION

NPWT in T2DM patients with neuropathic, noninfected DFU seems to lead to reduction of the Ang2 level. Influencing the level of Ang2 may constitute one of NPWT-related mechanisms to accelerate wound healing.