Negative-pressure wound therapy for management of diabetic foot wounds: a review of the mechanism of action, clinical applications, and recent developments

Negative Pressure Wound Therapy versus Conventional Dressing in Lower Limb Fractures: Systematic Review and Meta-analysis

Gustilo 3 lower limb fractures represent a significant challenge because of high complication risk. Two management strategies are commonly used for wound coverage until final closure: negative pressure wound therapy (NPWT) and conventional wound dressing (CWD), also described as standard wound coverage without subatmospheric pressure. Understanding their relative effectiveness is essential to improve patient outcomes. The aim of this systematic review and meta-analysis was to compare the efficacy of NPWT and CWD in Gustilo 3 lower limb fracture management, with a focus on overall rates, superficial infection, and deep infection rates. A systematic review of medical research databases was conducted in accordance with PRISMA guidelines. Studies comparing NPWT with CWD for Gustilo 3 fractures were included. Data extraction and quality assessment were performed. Treatment with CWD was associated with significantly higher rates of overall infection [pooled risk ratio (RR): 0.33; 95% confidence interval (CI): 0.14-0.51] and pooled risk difference (RD: 0.27; 95% CI: 0.15-0.38), superficial infection (pooled RR: 0.35; 95% CI: 0.04-0.66), and deep infection (pooled RR: 0.20; 95% CI: 0.02-0.38) compared with NPWT treatment. Overall infection rate remained significantly higher in the CWD group after analyzing only open tibia fractures (pooled RR: 0.35; 95% CI: 0.21-0.48). Nonunion rate was significant higher in the CWD group (pooled RR: 0.30; 95% CI: 0.00-0.59). Flap failure rate was similar in both groups (pooled RR: 0.09; 95% CI: -0.05 to 0.23). NPWT appears to be a reasonable option for wound management in Gustilo 3 lower limb fractures in terms of infection rates.

Deciphering Early-Stage Molecular Mechanisms of Negative Pressure Wound Therapy in a Murine Model

Negative Pressure Wound Therapy (NPWT) is a commonly employed clinical strategy for wound healing, yet its early-stage mechanisms remain poorly understood. To address this knowledge gap and overcome the limitations of human trials, we establish an NPWT C57BL/6JNarl mouse model to investigate the molecular mechanisms involved in NPWT. In this study, we investigate the intricate molecular mechanisms through which NPWT expedites wound healing. Our focus is on NPWT's modulation of inflammatory immune responses and the concurrent orchestration of multiple signal transduction pathways, resulting in shortened coagulation time and reduced inflammation. Notably, we observe a significant rise in dickkopf-related protein 1 (DKK-1) concentration during NPWT, promoting the differentiation of Hair Follicle Stem Cells (HFSCs) into epidermal cells, expediting wound closure. Under negative pressure, macrophages express and release DKK-1 cytokines, crucial for stimulating HFSC differentiation, as validated in animal experiments and in vitro studies. Our findings illuminate the inflammatory dynamics under NPWT, revealing potential signal transduction pathways. The proposed framework, involving early hemostasis, balanced inflammation, and macrophage-mediated DKK-1 induction, provides a novel perspective on enhancing wound healing during NPWT. Furthermore, these insights lay the groundwork for future pharmacological advancements in managing extensive wounds, opening avenues for targeted therapeutic interventions in wound care.

Understanding the ideal wound healing mechanistic behavior using in silico modelling perspectives: A review

Complexity of the entire body precludes an accurate assessment of the specific contributions of tissues or cells during the healing process, which might be expensive and time consuming. Because of this, controlling the wound's size, depth, and dimensions may be challenging, and there is not yet an efficient and reliable chronic wound model representation. Furthermore, given the inherent challenges associated with conducting non-invasive in vivo investigations, it becomes peremptory to explore alternative methodologies for studying wound healing. In this context, biologically-realistic mathematical and computational models emerge as a valuable framework that can effectively address this need. Therefore, it might improve our approach to understanding the process at its core. This article will examines all facets of wound healing, including the kinds, pathways, and most current developments in wound treatment worldwide, particularly in silico modelling utilizing both mathematical and structure-based modelling techniques. It may be helpful to identify the crucial traits through the feedback loop of computer models and experimental investigations in order to build innovative therapies to cure wounds. Hence the effectiveness of personalised medicine and more targeted therapy in the healing of wounds may be enhanced by this interdisciplinary expertise.

Ipomoea pes-tigridis L. extract accelerates wound healing in Wistar albino rats in excision and incision models

ETHNOPHARMACOLOGICAL RELEVANCE

An annual herb, Ipomoea pes-tigridis L. (Convolvulaceae) is widely used for its anti-inflammatory and anti-spasmodic properties in traditional medicine. As well as treating wounds, fever, skin disorders, and other ailments, it is also used for other purposes.

AIM OF THE STUDY

This study investigated polyphenolic content, antioxidant activity, RP-HPLC, wound healing, and antioxidant enzyme activity. In terms of I. pes-tigridis potential for healing wounds, there is no scientific data available. Hence this study is designed to use animal models to investigate the ethnopharmacological report.

MATERIALS METHODS

The crude extracts of stem and leaf were subjected to phytochemicals, TPC, TTC, TFC, and free radical scavenging assays (DPPH, ABTS, etc). Excision and incision models were used to assess wound healing using the screened extracts (IPLEA, IPLM, IPSEA, and IPSM). Various tissue parameters (hydroxyproline, hexosamine, hexuronic acid content), as well as antioxidant enzyme activity (SOD, Catalase, GPX, LPO), were also examined.

RESULTS

The maximum amount of polyphenolic content was found in IPLM (TPC- 118.86 ± 5.94 mg GAE/g, TTC - 75.25 ± 2.64 mg TAE/g, and TFC-25.73 ± 0.99 mg GAE/g) with significant IC50 value of 1.65 ± 0.87 μg/mL among all the extracts. Coumaric acid was reported high (92.86 mg/g) in RP-HPLC analysis of crude extract in IPLEA. The in vivo excision wound healing model revealed that 1% IPLM had better healing property with the maximum wound healing area (0.098 ± 0.03 cm) and wound concentration (95.56 ± 1.95%) was reported with the significance level of ***P < 0.001, **P < 0.01, *P < 0.05. In the incision model, IPLM represented maximum tensile strength (27500 gf). A significant functional effect of the granulation tissue parameters and enzyme antioxidants on the wound-healed area of dry tissue was also observed. Finally, the histopathological analysis showed enhanced re-epithelialization, fibroblast proliferation, and collagen synthesis in wound-treated animal tissue in both models.

CONCLUSION

According to the present study, antioxidant-rich I. pes-tigridis promotes healthy cell regeneration while reducing inflammation and oxidative stress for wound healing. Additionally, it also enhances circulation and promotes healing.

Evolving Role of Negative Pressure Wound Therapy with Instillation and Dwell Time (NPWTi-d-) in Management of Trauma and Orthopaedic Wounds: Mechanism, Applications and Future Perspectives

Introduction

Negative Pressure Wound Therapy (NPWT) is a well-established method to promote wound healing by delivering negative pressure (a vacuum) at the wound site. Enhancement of NPWT techniques may allow an innovative way of treating trauma and orthopaedic wounds which provide unique challenges. We explore the role of negative pressure wound therapy with instillation and dwell time (NPWTi-d-) in the management of trauma and orthopaedic wounds.

Materials and Methods

A comprehensive search strategy was conducted using databases of PubMed, Web of Science, Google Scholar, and Cochrane Library with the search words of 'NPWTid' or 'NPWTi-d-' or 'NPWT with instillation' or 'Negative pressure wound treatment with instillation' to generate this narrative review. The mechanism of action of NPWTi-d-, installation solutions and current applications in the trauma and orthopaedic wounds is evaluated.

Results

NPWTi-d- provides additional mechanism to promote wound healing in a spectrum of acute and chronic orthopaedic wounds. The technique allows local delivery of hydration and elution of antibiotics to support growth of healthy granulation tissue. Various mechanism of actions contribute in drawing the wound edges together, reduce oedema, help decontamination, deliver local antibiotic and promote healing.

Conclusion

NPWTi-d- permits an enhanced, supplementary technique to encourage wound healing in challenging traumatic and orthopaedic wounds. Future applications of NPWTi-d- will depend on cost-effectiveness analysis and development of its application guidelines based on longitudinal, randomized controlled research trials.

Evaluation of Negative Pressure Wound Therapy in the Management of Fournier's Gangrene

Introduction Necrotizing soft tissue infections (NSTIs), including Fournier's gangrene (FG), are severe polymicrobial bacterial infections characterized by rapidly spreading inflammation and tissue necrosis. This study aims to compare the clinical outcomes of vacuum-assisted closure (VAC) dressing and conventional dressing in patients with FG. Materials and methods A prospective study was conducted from December 2020 to May 2022, including patients with clinical features suggestive of FG. Patients were divided into two groups: conventional dressing and VAC dressing. Relevant clinical data, including age, duration of hospital stay, wound status, Fournier's gangrene severity index (FGSI) scores, sepsis markers (C-reactive protein (CRP), neutrophil-to-lymphocyte ratio, and procalcitonin), and pain assessment, were recorded and compared between the two groups. Results A total of 84 patients were included in the study, with 42 patients in each group. The mean age was 57.48 ± 15.74 years in the conventional dressing group and 50.83 ± 13.95 years in the VAC dressing group. VAC dressing was associated with a significantly shorter duration of hospital stay (8.14 ± 3.13 days) compared to conventional dressing (11.36 ± 4.75 days). The average time taken for wound closure was significantly reduced in the VAC dressing group (63 ± 14.81 days) compared to the conventional dressing group (112.56 ± 13.82 days). FGSI scores showed significant improvement after debridement in both groups, with lower scores in the VAC dressing group at discharge. Sepsis markers such as CRP and serum procalcitonin exhibited a significant decrease after VAC application. Discussion The study demonstrates that VAC therapy is associated with better clinical outcomes in FG, including reduced duration of hospital stay, faster wound closure, improved FGSI scores, decreased sepsis markers, and reduced pain. These findings align with previous studies highlighting the advantages of VAC therapy over conventional dressing methods. Conclusion VAC therapy provides significant benefits in the management of FG, leading to improved clinical outcomes and patient quality of life. It offers advantages such as shorter hospital stays, faster wound closure, and reduced sepsis markers. The application of VAC dressing should be considered a valuable treatment modality for FG.

Influence of Closed-incision Negative Pressure Wound Therapy on Abdominal Site Complications in Autologous Breast Reconstruction

Background

Closed-incision negative pressure wound therapy (ciNPWT) has shown promise in reducing surgical wound complications. Among its numerous benefits, it allows for exudate management and tension offloading from wound edges. The purpose of this systematic review and meta-analysis was to assess the efficacy of prophylactic ciNPWT versus conventional dressings on abdominal donor site complications in microsurgical breast reconstruction (MR).

Methods

A systematic review was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in January 2023. PubMed and Embase were searched to identify all relevant studies. Data collected included rates of total wound complications, wound dehiscence, infection, seroma, and length of hospital stay.

Results

A total of 202 articles were screened, and eight studies (1009 patients) met the inclusion criteria. Use of ciNPWT was associated with a significantly lower rate of wound dehiscence (OR, 0.53; 95% confidence interval, 0.33-0.85; P = 0.0085, I2 = 0%). There was no significant difference in the rate of total wound complications [odds ratio (OR), 0.63; 95% CI, 0.35-1.14; P = 0.12, I2 = 69%], donor site infection (OR, 0.91; 95% CI, 0.42-1.50; P = 0.47, I2 = 13%), seroma (OR, 0.74; 95% CI, 0.22-2.49; P = 0.63, I2 = 57%), or length of hospital stay (SMD, 0.089; 95% CI, -0.13-0.35; P = 0.37, I2 = 29%).

Conclusions

Although exudate management by ciNPWT fails to reduce surgical site infection, seroma formation, and overall length of stay, ciNPWT tension offloading properties seem to be associated with lower rates of wound dehiscence when compared with conventional dressings in abdominal-based autologous breast reconstruction.

The Application of Double-Layer-Vacuum-Assisted Closure Therapy With Flap Repair of Soft Tissue Defects Near the Eyes or EarDL-VAC Therapy

OBJECTIVE

We aimed to introduce and evaluate the safety of double-layer-vacuum-assisted closure (DL-VAC) therapy with flap repair of the wound near the eyes or ears.

METHODS

This study is case reports of 2 patients who underwent DL-VAC therapy for tissue defects near the eyes or ears. The detailed process of the DL-VAC therapy is carefully described in this study. The postoperative wound healing process was closely observed. The biggest concern was the treatment outcome of DL-VAC therapy on the eyes and ears.

RESULTS

Two patients underwent DL-VAC therapy due to their soft tissue defects close to the eyes or ears. Both patients achieved primary wound healing and the flaps survived during the follow-up period, which ranged from 1 to 24 months. Patients did not receive any dressing change until the VAC device was removed on the 5th to 7th postoperative day. No severe complications appeared and the patients were satisfied with both appearance and function.

CONCLUSIONS

Double-layer-vacuum-assisted closure therapy is an effective and safe option for the treatment of wounds near the eyes and ears.

Comparative study of various dressing techniques in diabetic foot ulcers in the Indian population: a single-center experience

Introduction

A prospective randomized study was conducted to evaluate and compare the efficacy of conventional dressing, foam dressing, and vacuum-assisted closure (VAC) in the management of diabetic foot ulcers (DFUs).

Material and methods

Ninety patients with DFU were included in the study conducted between 2018 and 2021 at a tertiary care center. Group 1 patients (n = 30) were treated with conventional dressing, group 2 patients (n = 30) with foam dressing, and group 3 patients (n = 30) with VAC dressing. The duration of treatment, number of debridement, need for the secondary procedure, cost of treatment, and duration of hospital stay were compared between the three groups.

Results

There was a significant difference in the duration of treatment among the three groups with VAC being the least (group 1, 31.17 days; group 2, 24.13 days; group 3, 15.17 days). The mean number of debridement was also significantly less in the VAC group (2.37, 2.43, and 1.60, respectively). The need for the secondary procedure, like flap or skin graft, was also the least in the VAC group, although insignificant. The mean hospital stay of the study subjects was 31.17 days, 24.13 days, and 15.17 days in the 3 groups, respectively. The mean cost of the treatment was 3076.67 INR, 3717.33 INR, and 10,680 INR, respectively.

Conclusion

VAC dressing is the best option amongst the available dressing modalities in terms of faster healing and a short hospital stay. Foam dressing does provide an economically viable option with better results than conventional dressing.

Autologous wound margin point columnar full‐thickness skin grafting combined with negative pressure wound therapy improves wound healing in refractory diabetic foot ulcers

Diabetic lower extremity ulcers (DLEUs) are a severe complication of diabetes mellitus (DM) and are difficult to heal. This study aimed to explore the efficacy of autologous point columnar full-thickness skin graft taken from the ulcer wound margin combined with negative pressure wound therapy (NPWT) in refractory DLEUs. This is a prospective cohort study. A total of 40 inpatients with refractory DLEUs were recruited in the Diabetes Foot Center of Guangxi Zhuang Autonomous Region People's Hospital from October 2019 to November 2021. According to the doctors' professional suggestions and the patients' personal wishes, these enrolled patients were divided into two groups based on different topical wound management: the graft group (n = 18) and the conventional wound therapeutic (CWT) group (n = 22). The efficacy evaluations included the time to complete re-epithelialization of the wound and healing speed within 14 days of graft treatment or after 14 days of graft treatment in the two groups. Before the treatment, the graft group had a significantly larger ulcer area than the CWT group [27.22 (15.28, 46.59) versus 10.92 (7.00, 24.93) cm² , P < .01]. However, the time to complete wound re-epithelialization in the graft group was shorter than in the CWT group [58.22 ± 30.60 versus 86.09 ± 49.54 d, P < .05]. Meanwhile, the healing speed in graft group was markedly faster than in CWT group, whether within 14 days [0.60 (0.40, 0.92) versus 0.16 (0.07, 0.34) cm² /d, P < .01] or after 14 days of graft treatment [0.57 (0.45, 0.91) versus 0.13 (0.08, 0.27) cm² /d, P < .01]. However, the total treatment cost in the graft group was lower than in the CWT group [419.59 ± 137.20 versus 663.97 ± 497.02 $, P < .05]. The novel treatment modality of autologous full-thickness skin graft taken from the ulcer wound margin combined with NPWT has hereby proposed for the first time, and is a safe, effective, and reliable method with a good performance-to-cost ratio to promote wound healing and shorten the healing time for DLEUs.

Antibiotic-loaded Bone Cement Combined with Vacuum-assisted Closure Facilitating Wound Healing in Wagner 3-4 Diabetic Foot Ulcers

This study explored the clinical effectiveness of antibiotic-loaded bone cement (ALBC) combined with vacuum-assisted closure (VAC) on the treatment of Wagner 3-4 diabetic foot ulcers (DFUs). This is a retrospective study, including 32 patients with Wagner 3-4 DFUs who had undergone treatment between August 2019 and June 2021. Patient age, sex, Hemoglobin A1c (HbA1c), body mass index (BMI), ankle brachial index (ABI), white blood cells (WBC), C-reactive protein (CRP) levels, comorbidities and wound closure methods were recorded. Patients were divided into the study group and control group according to the treatment modality. Patients in the study group received the combination treatment of ALBC and VAC, while patients in the control group received single VAC treatment. Clinical endpoints were assessed and compared between the two groups, including wound complete healing time and complications after operation. All patients were followed-up 6 months postoperation. Results showed that the mean healing time of the study group (44.20 ± 16.72 days) was shorter than that of the control group (64.00 ± 29.85 days) (P < .05). The infection rate of the study group on the 10th day postoperation was lower than that of the control group (6.67%, 47.06%, P < .05). And there were no significant statistical differences between the two groups in terms of bleeding and necrosis complications postoperation (P = .603, P = .603). Based on the findings, we conclude that the application of ALBC combined with VAC can facilitate wound healing in Wagner 3-4 DFUs patients. It can help to control wound infections and shorten wound healing time.

Ending surgical site infection by negative pressure wound therapy (NPWT): A case report

Introduction and importance

Hundreds of millions of people may go through surgery every year worldwide. Surgical site infection (SSI) is one of the most common complications of the surgery. SSI increases the duration of treatment, delays wound healing, increases the use of antibiotics, and in severe cases, causes patient death and imposes high costs on the patient and the health care system.

Case presentation

The present case report is a 45-year-old man with a history of 8-years type 2 diabetes who underwent surgery for a pilonidal cyst. Despite routine dressing changes (cleansing the wound with saline and applying sterile gauze) twice a day and intravenous (IV) antibiotic therapy, no improvement was observed and the wound became infected. The patient was referred to our wound care team. NPWT (applying a pressure of 125 mm Hg intermittently) was performed 4 times a day for one week. Also, after each session until the beginning of the next session, the patient's wound was bandaged. The patient's wound healed completely after about 2 months.

Clinical discussion

Patients with diabetes mellitus will have difficulty in wound healing due to microvascular changes. Thus, efficient therapeutic methods such as surgical debridement, maggot therapy, and NPWT are necessary for management of surgical site infection.

Conclusion

This case report was showed that NPWT is an affordable and highly efficacious treatment method for management of SSI in patients with diabetes mellitus. Therefore, it is suggested that wound care teams may use NPWT to treat SSIs.

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Advances in technology for patients with diabetes mellitus have increased their lifespan.

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NPWT is an effective treatment for deep wounds.

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NPWT is an efficacious treatment method for management of SSI in patients with diabetes mellitus.

Emerging treatment strategies in wound care

Wound healing is a complex process in tissue regeneration through which the body responds to the dissipated cells as a result of any kind of severe injury. Diabetic and non-healing wounds are considered an unmet clinical need. Currently, different strategic approaches are widely used in the treatment of acute and chronic wounds which include, but are not limited to, tissue transplantation, cell therapy and wound dressings, and the use of an instrument. A large number of literatures have been published on this topic; however, the most effective clinical treatment remains a challenge. The wound dressing involves the use of a scaffold, usually using biomaterials for the delivery of medication, autologous stem cells, or growth factors from the blood. Antibacterial and anti-inflammatory drugs are also used to stop the infection as well as accelerate wound healing. With an increase in the ageing population leading to diabetes and associated cutaneous wounds, there is a great need to improve the current treatment strategies. This research critically reviews the current advancement in the therapeutic and clinical approaches for wound healing and tissue regeneration. The results of recent clinical trials suggest that the use of modern dressings and skin substitutes is the easiest, most accessible, and most cost-effective way to treat chronic wounds with advances in materials science such as graphene as 3D scaffold and biomolecules hold significant promise. The annual market value for successful wound treatment exceeds over $50 billion US dollars, and this will encourage industries as well as academics to investigate the application of emerging smart materials for modern dressings and skin substitutes for wound therapy.

The Role of Negative Pressure Wound Therapy (NPWT) in the Management of Vasculitic Wounds: Case Series of Eight Patients

Vasculitic ulcers belong to the category of atypical ulcers and are traditionally very slow to heal. The aim of this study is to retrospectively analyze the files of eight patients with vasculitic ulcers treated with negative pressure wound therapy (NPWT). Immunosuppression was initiated at least two weeks prior to starting NPWT. We suggest that this is a safe and promising protocol to treat these hard-to-heal ulcers.

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.

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.

Wound Healing: From Passive to Smart Dressings

The universal increase in the number of patients with nonhealing skin wounds imposes a huge social and economic burden on the patients and healthcare systems. Although, the application of traditional wound dressings contributes to an effective wound healing outcome, yet, the complexity of the healing process remains a major health challenge. Recent advances in materials and fabrication technologies have led to the fabrication of dressings that provide proper conditions for effective wound healing. The 3D-printed wound dressings, biomolecule-loaded dressings, as well as smart and flexible bandages are among the recent alternatives that have been developed to accelerate wound healing. Additionally, the new generation of wound dressings contains a variety of microelectronic sensors for real-time monitoring of the wound environment and is able to apply required actions to support the healing progress. Moreover, advances in manufacturing flexible microelectronic sensors enable the development of the next generation of wound dressing substrates, known as electronic skin, for real-time monitoring of the whole physiochemical markers in the wound environment in a single platform. The current study reviews the importance of smart wound dressings as an emerging strategy for wound care management and highlights different types of smart dressings for promoting the wound healing process.

Biofilms in Diabetic Foot Ulcers: Impact, Risk Factors and Control Strategies

Diabetic foot ulcers (DFUs) are a serious complication from diabetes mellitus, with a huge economic, social and psychological impact on the patients' life. One of the main reasons why DFUs are so difficult to heal is related to the presence of biofilms. Biofilms promote wound inflammation and a remarkable lack of response to host defences/treatment options, which can lead to disease progression and chronicity. In fact, appropriate treatment for the elimination of these microbial communities can prevent the disease evolution and, in some cases, even avoid more serious outcomes, such as amputation or death. However, the detection of biofilm-associated DFUs is difficult due to the lack of methods for diagnostics in clinical settings. In this review, the current knowledge on the involvement of biofilms in DFUs is discussed, as well as how the surrounding environment influences biofilm formation and regulation, along with its clinical implications. A special focus is also given to biofilm-associated DFU diagnosis and therapeutic strategies. An overview on promising alternative therapeutics is provided and an algorithm considering biofilm detection and treatment is proposed.

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.

Negative pressure wound therapy promotes wound healing by suppressing macrophage inflammation in diabetic ulcers

Aim: This work aims to explore the biological role of negative pressure wound therapy (NPWT) in the treatment of diabetic ulcer. Materials & methods: Full-thickness skin defects were created in diabetic (db/db) and non diabetic (db/m) mice to create wound models. The mice were received NPWT or rapamycin injection. Mouse macrophage cells (Raw264.7) were treated with lipopolysaccharide to induce inflammatory response, and then received negative pressure treatment. We observed the wound healing of mice and examined gene and protein expression and CD68⁺ macrophage levels. Results: NPWT notably enhanced the wound closure ratio, and inhibited the LC3-II/LC3-I ratio and Beclin-1 expression in diabetes mellitus (DM) mice. NPWT decreased CD68⁺ macrophage levels in wound tissues of DM mice. The influence conferred by NPWT was abolished by rapamycin treatment. Negative pressure repressed the LC3-II/LC3-I ratio and the expression of Beclin-1, TNF-α, IL-6 and IL-1β in the Raw264.7 cells. Conclusion: NPWT promotes wound healing by suppressing autophagy and macrophage inflammation in DM.

Extracellular vesicle-based therapeutics for the regeneration of chronic wounds: current knowledge and future perspectives

Chronic wounds are still an intractable medical problem for both clinicians and researchers and cause a substantial social and medical burden. Current clinical approaches can only manage wounds but have limited capacity to promote the regeneration of chronic wounds. As a type of natural nanovesicle, extracellular vesicles (EVs) from multiple cell types (e.g., stem cells, immune cells, and skin cells) have been shown to participate in all stages of skin wound healing including inflammation, proliferation, and remodeling, and display beneficial roles in promoting wound repair. Moreover, EVs can be further re-engineered with genetic/chemical or scaffold material-based strategies for enhanced skin regeneration. In this review, we provide an overview of EV biology and discuss the current findings regarding the roles of EVs in chronic wound healing, particularly in immune regulation, cell proliferation and migration, angiogenesis, and extracellular matrix remodeling, as well as the therapeutic effects of EVs on chronic wounds by genetic modification, in combination with functionalized biomaterials, and as drug carriers. We also discuss the challenges and perspectives of translating EV-based therapies into clinical wound care in the future.

"Low cost, modified negative pressure wound therapy in infected orthopaedic wounds: can it be as effective as its costly counterparts?"

BACKGROUND

Infected wounds pose a great financial burden on our healthcare system. Negative pressure wound therapy (NPWT) has brought a paradigm shift in the management of these wounds. However, availability and high cost of a conventional NPWT system remains a challenge. We carried out this study to assess whether we can replicate functioning of the conventional NPWT system using resources which are easily available in most hospitals and determine the clinical efficacy and cost effectiveness of the same.

MATERIAL AND METHODS

A prospective study was conducted in the orthopaedic department at our tertiary care institute from January 2018 to December 2019. Fifty six patients with contaminated or infected orthopaedic wounds were included in the study. Wound dressings were carried out by modified negative pressure therapy and their results were studied.

RESULTS

The study group consisted of 41 males and 15 females. Duration of stay in hospital ranged from 6 to 37 days, with average duration of 14.05 days. Wound closure was achieved by secondary suturing in 18 (32.2%) of the cases and split thickness skin grafting in 38 (67.8%) of the cases. Wound assessment done using the revised Photographic wound assessment tool revealed an average of 60% reduction in scores, post procedure. The average cost of the dressing could be considerably reduced during the study by the use of available material.

CONCLUSION

Through our study we describe a simple and effective method of application of negative pressure dressings which may be beneficial in low resource settings. Our method is easily reproducible and does not require expertise for its application, at the same time it is cost effective and efficient in wound care.

Vacuum sealing drainage with instillation in the treatment of necrotising soft-tissue infection: a retrospective analysis

Objective:

Necrotising soft-tissue infection is a rare but life-threatening infectious disease with high morbidity and mortality. It is typically caused by toxin-producing bacteria and characterised clinically by a very rapid progression of the disease with significant local tissue destruction. In this study, we intend to explore effective wound management to control the invasive infection and to decrease the high mortality.

Method:

This retrospective analysis explored the wound management and mortality in patients with necrotising soft-tissue infection. Extensive debridement, vacuum sealing drainage (VSD) with normal saline instillation combined with broad-spectrum or sensitive antibiotics, and supportive therapies were used.

Results:

All 17 patients included in the analysis survived. The microbiology of 11 patients was found to be polymicrobial. Of the patients, 14 were discharged with completely healed wounds and three were transferred to a local hospital after the systemic and invasive wound infection was controlled.

Conclusion:

Our experiences revealed the outstanding effect of VSD with instillation in removing the debris of necrotising tissue on the wound bed, in the continual and complete drainage of wound exudates, and in prompting wound healing.

[Clinical application of nose ring drain in severe diabetic foot infection]

Objective

To evaluate the effectiveness of the nose ring drain (NRD) in treatment of severe diabetic foot infection.

Methods

The clinical data of 35 patients with severe diabetic foot infection who were treated with NRD between June 2017 and June 2019 were analyzed retrospectively. There were 24 males and 11 females with an average age of 54.5 years (range, 28-82 years). All of them were type 2 diabetic patients. The diabetes duration was 3-20 years, with an average of 9.4 years. The diabetic foot duration was 4 months to 2 years, with an average of 1.16 years. There were 16 cases of left foot and 19 cases of right foot. According to Wagner's grading, there were 11 cases of grade 2, 20 cases of grade 3, and 4 cases of grade 4, all of which were moderate and severe infection of diabetic foot wound. Postoperative wounds were treated with "nibble-like" debridement until the patient's epidermis regenerated and healed. During the treatment process, the indexes of bacterial culture type of wound secretions, duration of antibiotic therapy, wound healing method, healing time, amputation rate, and other indicators were analyzed and summarized.

Results

All 35 patients were followed up 3-6 months, with an average of 4.5 months. Postoperative bacterial culture of wounds showed that 5 cases of Staphylococcus aureus, 4 cases of Pseudomonas aeruginosa, 5 cases of Escherichia coli, 3 cases of Enterobacter cloacae, 3 cases of coagulase-negative Staphylococcus, and 15 cases of other types were detected. The duration of antibiotic therapy ranged from 3 to 15 days, with an average of 9.1 days. The wound was autolytically healed without skin grafting, and the healing time was 62-82 days, with an average of 72.3 days. During the follow-up, 3 cases (8.6%) had amputation due to the patient's poor blood glucose control, which led to a large spread of infection. In addition, among the other patients with wound healing, there was no recurrence of wound infection or new ulcer on the original surface.

Conclusion

The NRD is a simple operation for treatment of severe diabetic foot infection, which can effectively control wound infections and promote wound healing and regeneration without skin grafting.

A modified negative pressure wound therapy for the treatment of refractory wounds: A preliminary study

Negative pressure wound therapy (NPWT) is an important therapy for the management of refractory wounds. The aim of this retrospective preliminary study was to introduce a modified NPWT (m-NPWT) and compared the efficacy of it with conventional NPWT (c-NPWT) in the management of refractory wounds.A total of 127 patients with refractory wounds receiving the NPWT from January 2010 to October 2017 in our hospital were retrospectively reviewed. The demographics and clinical data were collected from medical records and compared between m-NPWT group and c-NPWT group.There were 65 patients in c-NPWT group and 62 patients in m-NPWT group. No significant difference was observed between 2 groups in antimicrobial use (P = .51), hospitalization time (P = .24), wound-healing rate (P = .44) or complication rate (P = .59). However, patients in m-NPWT group had shorter wound-healing time (24.82 vs 27.66 days, P < .01), less debridement times (1.23 vs 2.08, P < .01), less total cost (3743.93 vs 6344.33 yuan, P < .01) and higher satisfaction rate (56/62 vs 44/65, P = .02) compared to those in c-NPWT group.The m-NPWT technique was an efficient and safe alternative therapy for refractory wounds.

Transmetatarsal amputation: A 12 year retrospective case review of outcomes

BACKGROUND

Diabetic foot pathology has rapidly increased, presenting a vast economic burden with severe implications for patients. Establishing effective limb salvage techniques such as transmetatarsal amputation is essential to offer viable alternatives to major limb amputation in severe foot infection, where outcomes are variable and mortality rates high.

METHODS

A retrospective review of outcomes was performed on patients who underwent TMA at a single United Kingdom hospital between 2005-2017. Healing rate and time to healing, mortality, duration of hospital admission and incidence of revision surgery was evaluated. Forty-seven patients had 54 TMA's by the Podiatric Surgery team. Data was assessed for Mean (SD) and Median. The impact of co-morbidities was considered and the perioperative and surgical management reviewed to identify techniques which may improve outcomes.

RESULTS

A 78% healing rate was achieved. Six patients (11%) died before healing. The aremaining 11% did not heal and resulted in major limb amputation. No further surgery to the same foot was required after the TMA healed. A Median healing time of 83 days was identified and the Median duration of hospital admission was 24 days. Adjunctive wound care products may to have a positive impact on these factors. Five-year mortality was 43%, and demonstrated an association with renal and/or vascular pathology. All patients had diabetes, with many also having Peripheral Vascular Disease (PVD). Almost all TMA's failing to heal had PVD. The presence and severity of renal disease also seemed to have a negative impact on wound healing.

CONCLUSION

Positive healing and mortality rates with low need for revision surgery support TMA to be an effective alternative to major limb amputation. Adjunctive agents may have a positive impact on wound healing and length of hospital admission. Skilled surgical technique and Multidisciplinary work is essential for positive long-term outcomes and cost-effective care.

EWMA Document: Negative Pressure Wound Therapy

1. Introduction Since its introduction in clinical practice in the early 1990's negative pressure wounds therapy (NPWT) has become widely used in the management of complex wounds in both inpatient and outpatient care.¹ NPWT has been described as a effective treatment for wounds of many different aetiologies^2,3 and suggested as a gold standard for treatment of wounds such as open abdominal wounds,^4-6 dehisced sternal wounds following cardiac surgery^7,8 and as a valuable agent in complex non-healing wounds.^9,10 Increasingly, NPWT is being applied in the primary and home-care setting, where it is described as having the potential to improve the efficacy of wound management and help reduce the reliance on hospital-based care.¹¹ While the potential of NPWT is promising and the clinical use of the treatment is widespread, highlevel evidence of its effectiveness and economic benefits remain sparse.^12-14 The ongoing controversy regarding high-level evidence in wound care in general is well known. There is a consensus that clinical practice should be evidence-based, which can be difficult to achieve due to confusion about the value of the various approaches to wound management; however, we have to rely on the best available evidence. The need to review wound strategies and treatments in order to reduce the burden of care in an efficient way is urgent. If patients at risk of delayed wound healing are identified earlier and aggressive interventions are taken before the wound deteriorates and complications occur, both patient morbidity and health-care costs can be significantly reduced. There is further a fundamental confusion over the best way to evaluate the effectiveness of interventions in this complex patient population. This is illustrated by reviews of the value of various treatment strategies for non-healing wounds, which have highlighted methodological inconsistencies in primary research. This situation is confounded by differences in the advice given by regulatory and reimbursement bodies in various countries regarding both study design and the ways in which results are interpreted. In response to this confusion, the European Wound Management Association (EWMA) has been publishing a number of interdisciplinary documents^15-19 with the intention of highlighting: The nature and extent of the problem for wound management: from the clinical perspective as well as that of care givers and the patients Evidence-based practice as an integration of clinical expertise with the best available clinical evidence from systematic research The nature and extent of the problem for wound management: from the policy maker and healthcare system perspectives The controversy regarding the value of various approaches to wound management and care is illustrated by the case of NPWT, synonymous with topical negative pressure or vacuum therapy and cited as branded VAC (vacuum-assisted closure) therapy. This is a mode of therapy used to encourage wound healing. It is used as a primary treatment of chronic wounds, in complex acute wounds and as an adjunct for temporary closure and wound bed preparation preceding surgical procedures such as skin grafts and flap surgery. Aim An increasing number of papers on the effect of NPWT are being published. However, due to the low evidence level the treatment remains controversial from the policy maker and health-care system's points of view-particularly with regard to evidence-based medicine. In response EWMA has established an interdisciplinary working group to describe the present knowledge with regard to NPWT and provide overview of its implications for organisation of care, documentation, communication, patient safety, and health economic aspects. These goals will be achieved by the following: Present the rational and scientific support for each delivered statement Uncover controversies and issues related to the use of NPWT in wound management Implications of implementing NPWT as a treatment strategy in the health-care system Provide information and offer perspectives of NPWT from the viewpoints of health-care staff, policy makers, politicians, industry, patients and hospital administrators who are indirectly or directly involved in wound management.

The molecular mechanism study of insulin in promoting wound healing under high-glucose conditions

BACKGROUND

Wound healing is a complex process in bone development. The aim of this study was to explore the molecular mechanism study of insulin in promoting wound healing.

METHODS

Firstly, the acute human monocyte leukemia cell lines were induced to differentiate into macrophages. Secondly, the porphyromonas gingivalis was applied to mix with the differentiated macrophages. Thirdly, the effect of different concentrations of insulin (0 ng/mL, 5 ng/mL, 50 ng/mL, 100 ng/mL, 200 ng/mL, 500 ng/mL, and 1,000 ng/mL) on the phagocytosis of macrophages and production of reactive oxygen species was investigated. Depending on these experiments, the optimal insulin concentration was used to treat the macrophages at different time points (0 hours and 0.5 hours) to identify the differentially expressed mRNAs. Finally, functional analysis including gene ontology (GO) and the Kyoto Encyclopedia of Genes and Genomes (KEGG) and protein-protein interaction (PPI) analysis was carried out to explore the biological function of these differentially expressed mRNAs.

RESULTS

The test of phagocytosis function and production of reactive oxygen species showed that 200 ng/mL insulin treatment had a significant influence on antibacterial and production of reactive oxygen species. In RNA sequencing, a total of 415 (245 upregulated and 170 downregulated) differentially expressed mRNAs were identified between different time points. Two important signaling pathways including endocytosis and systemic lupus erythematosus were found in the KEGG enrichment analysis. In the PPI network, several hub proteins encoded by differentially expressed mRNA including ALB, HIP1R, RAB5A, HIST1H2BJ, HIST1H3G, and HIST1H2BO were identified.

CONCLUSION

Our work demonstrated that several differentially expressed mRNAs, such as EGR1, RAB34, ALB, HIP1R, RAB5A, HIST1H2BJ, HIST1H3G, and HIST1H2BO and two important signaling pathways including endocytosis and systemic lupus erythematosus may play important roles in the bone wound healing.

"Gravity" - a new simple negative pressure wound therapy self-build design for low income countries

Negative Pressure Wound Therapy (NPWT) is prohibitively expensive at the moment and therefore not easily accessible in low-income countries. An additional problem is the requirement of consistent reliable electricity to power the devices. A new low-cost NPWT device was designed from low cost and simple materials and it can be built and operated following a simple set of instructions. The so-called Gravity device was made from parts costing just under £6 GBP (May 2016) and it creates a constant pressure of 125 mmHg. Gravity operated from 4 hours and 40 minutes up to 5 hours and 18 minutes before needing to be reset. This reset can be achieved without patient involvement. Gravity was taken to Kenya by a Doctor on 5 May 2016 to be evaluated. A NPWT device prototype was successfully made and positive feedback was received from Kenya.

Effect of negative-pressure wound therapy on the circulating number of peripheral endothelial progenitor cells in diabetic patients with mild to moderate degrees of ischaemic foot ulcer

Objective

To investigate the effect of negative-pressure wound therapy (NPWT) on the circulating number of endothelial progenitor cells (EPCs) in diabetic patients with mild to moderate degrees of ischemic foot ulcer.

Methods

We selected 84 diabetic patients who had a foot ulcer with a duration of at least four weeks and who had an ankle-brachial index of 0.5–0.9. Patients were assigned to one two groups according to 2:1 randomization: NPWT group ( n = 56) and non-NPWT (patients who did not receive NPWT) group ( n = 28). The control group (NC group) was composed of 18 patients who had normal glucose tolerance and lower extremity ulcer without arteriovenous disease. NPWT was performed on the ulcer after debridement for one week for patients in both the NPWT group and the NC group, and the patients in the non-NPWT group received conventional treatment process. The circulating number of EPCs was measured before and after various treatments, and the factors influencing their changes were analysed.

Results

After NPWT, the circulating number of EPCs significantly increased in both the NPWT group and the NC group ((85.3 ± 18.1) vs. (34.1 ± 12.5)/106 cells; (119.9 ± 14.4) vs. (66.1 ± 10.6)/106 cells, both P < 0.05). In contrast, the circulating number of EPCs had no significant change in the non-NPWT group ((45.2 ± 19.4) vs. (34.7 ± 16.8)/106 cells, P > 0.05). In addition, the circulating levels of vascular endothelial growth factor (VEGF) and the protein expressions of VEGF and stromal cell-derived factor-1α (SDF-1α) in the granulation tissue significantly increased after NPWT in both the NPWT and the NC group, but there was no significant change in the non-NPWT group. Compared with the non-NPWT group, the changes in VEGF and SDF-1α levels in the sera and granulation tissue were all significantly higher in both the NPWT and NC groups ( P < 0.05, P < 0.01, respectively). There was no significant difference in changes in the circulating number of EPCs in the peripheral blood and levels of VEGF and SDF-1α in the sera and granulation tissue between the NPWT and NC groups. Correlation analysis showed that the change in the circulating number of EPCs was correlated with the changes of VEGF and SDF-1α levels in the sera and granulation of the NPWT and NC groups ( P < 0.05).

Conclusion

NPWT may increase the circulating number of EPCs in diabetic patients with mild to moderate ischaemic foot ulcer as in non-diabetic controls, which may be attributed to the upregulation of systemic and local VEGF and SDF-1α levels.

Negative pressure wound therapy in the treatment of diabetic foot ulcers may be mediated through differential gene expression

AIMS

Negative pressure wound therapy (NPWT) has been successfully used as a treatment for diabetic foot ulceration (DFU). Its mechanism of action on the molecular level, however, is not fully understood. We assessed the effect of NPWT on gene expression in patients with type 2 diabetes (T2DM) and DFU.

METHODS

We included two cohorts of patients-individuals treated with either NPWT or standard therapy. The assignment to NWPT was non-randomized and based on wound characteristics. Differential gene expression profiling was performed using Illumina gene expression arrays and R Bioconductor pipelines based on the 'limma' package.

RESULTS

The final cohort encompassed 21 patients treated with NPWT and 8 with standard therapy. The groups were similar in terms of age (69.0 versus 67.5 years) and duration of T2DM (14.5 versus 14.4 years). We identified four genes differentially expressed between the two study arms post-treatment, but not pre-treatment: GFRA2 (GDNF family receptor alpha-2), C1QBP (complement C1q binding protein), RAB35 (member of RAS oncogene family) and SYNJ1 (synaptic inositol 1,4,5-trisphosphate 5-phosphatase 1). Interestingly, all four genes seemed to be functionally involved in wound healing by influencing re-epithelialization and angiogenesis. Subsequently, we utilized co-expression analysis in publicly available RNA-seq data to reveal the molecular functions of GFRA2 and C1QBP, which appeared to be through direct protein-protein interactions.

CONCLUSIONS

We found initial evidence that the NPWT effect on DFUs may be mediated through differential gene expression. A discovery of the specific molecular mechanisms of NPWT is potentially valuable for its clinical application and development of new therapies.

Comparison of Vacuum-Assisted Closure Therapy and Conventional Dressing on Wound Healing in Patients with Diabetic Foot Ulcer: A Randomized Controlled Trial

Background:

Vacuum-assisted closure (VAC) therapy has been shown to be beneficial in a variety of wounds. However, evidence of its benefit in diabetic foot ulcers (DFUs), especially with respect to Indian population, is sparse.

Methodology:

This randomized controlled trial included DFUs of Wagner's Grades 1 and 2. Patients were further stratified with respect to DFU size <10 cm and ≥10 cm. Patients with vascular disease, osteomyelitis, and bilateral DFUs were excluded from the study. The enrolled patients were randomized to receive VAC therapy or conventional dressing. The time to wound healing, granulation tissue formation, and complications such as pain, infection, and bleeding were compared between the two groups.

Results:

A total of sixty patients were randomized, of which 27 in each group were analyzed. The mean time to healing in days was significantly less in VAC group (22.52 vs. 3.85; P < 0.0001). Mean time to achieve 75%–100% granulation tissue cover was significantly less in VAC group (23.33 vs. 32.15; P < 0.0001). Rate of granulation tissue formation was also found to be significantly better in VAC group (2.91 cm²/day vs. 2.16 cm²/day; P = 0.0306). There was no difference between the two groups with respect to wound infection and bleeding which are commonly attributed to VAC therapy. VAC therapy group had significantly lesser pain at week 3 (Visual Analog Scale score 3 vs. 4; P = 0.004).

Conclusion:

VAC therapy significantly decreases the time to complete wound healing, hastens granulation tissue formation, and reduces the ulcer area compared to conventional dressing. The study did not find any significant increase in the bleeding and infection in the VAC therapy group.

MnSOD is implicated in accelerated wound healing upon Negative Pressure Wound Therapy (NPWT): A case in point for MnSOD mimetics as adjuvants for wound management

Negative Pressure Wound Therapy (NPWT), a widely used modality in the management of surgical and trauma wounds, offers clear benefits over conventional wound healing strategies. Despite the wide-ranging effects ascribed to NPWT, the precise molecular mechanisms underlying the accelerated healing supported by NPWT remains poorly understood. Notably, cellular redox status-a product of the balance between cellular reactive oxygen species (ROS) production and anti-oxidant defense systems-plays an important role in wound healing and dysregulation of redox homeostasis has a profound effect on wound healing. Here we investigated potential links between the use of NPWT and the regulation of antioxidant mechanisms. Using patient samples and a rodent model of acute injury, we observed a significant accumulation of MnSOD protein as well as higher enzymatic activity in tissues upon NPWT. As a proof of concept and to outline the important role of SOD activity in wound healing, we replaced NPWT by the topical application of a MnSOD mimetic, Mn(III) meso-tetrakis(N-ethylpyridinium-2-yl)porphyrin (MnTE-2-PyP5+, MnE, BMX-010, AEOl10113) in the rodent model. We observed that MnE is a potent wound healing enhancer as it appears to facilitate the formation of new tissue within the wound bed and consequently advances wound closure by two days, compared to the non-treated animals. Taken together, these results show for the first time a link between NPWT and regulation of antioxidant mechanism through the maintenance of MnSOD activity. Additionally this discovery outlined the potential role of MnSOD mimetics as topical agents enhancing wound healing.

Negative-pressure wound therapy for management of chronic neuropathic noninfected diabetic foot ulcerations - short-term efficacy and long-term outcomes

PURPOSE

Negative pressure wound therapy (NPWT) is an adjunct method used in the treatment of diabetic foot ulceration (DFU). Real world data on its effectiveness and safety is scarce. In this prospective observational study, we assessed the short-term efficacy, safety, and long-term outcomes of NPWT in patients with type 2 diabetes (T2DM) and neuropathic, noninfected DFUs.

METHODS

Based on wound characteristics, mainly area (>1 vs. ≤1 cm²), 75 patients with DFUs treated in an outpatient clinic were assigned to NPWT (n = 53) or standard therapy (n = 22). Wound area reduction was evaluated after 8 ± 1 days. Long-term outcomes assessed included complete ulceration closure and recurrence rate.

RESULTS

Patients assigned to NPWT were characterized by greater wound area (15.7 vs. 2.9 cm²). Reduction in wound area was found in both the NPWT (-1.1 cm², -10.2%, p = 0.0001) and comparator group (-0.3 cm², -18.0%, p = 0.0038). No serious adverse events related to NPWT were noted. Within 1 year, 55.1% (27/49) of DFUs were closed in the NPWT group and 73.7% (14/19) in the comparator group (p = 0.15). In the logistic regression, wound duration and smaller initial area, but not treatment mode, were associated with closure. One-year follow-up after DFU resolution revealed an ~30.0% recurrence rate in both groups (p = 0.88).

CONCLUSIONS

NPWT is a safe treatment for neuropathic, nonischemic, and noninfected DFU in patients with T2DM, although this observational study did not prove its effectiveness over standard therapy. Additionally, we report a high rate of both closure and recurrence of ulcers, the latter irrespective of initial ulcer area.

A comparative analysis of skin substitutes used in the management of diabetic foot ulcers

OBJECTIVE

To compare the relative product cost and clinical outcomes of four skin substitutes used as adjunctive treatments for diabetic foot ulcers (DFUs).

METHOD

Medicare claims data from 2011 to 2014 were used to identify beneficiaries with diabetes and foot ulcers. Patients treated with one of four types of skin substitute (Apligraf, Dermagraft, OASIS, and MatriStem) were identified. The skin substitutes were compared on episode length; amputation rate; skin substitute utilisation; and skin substitute costs.

RESULTS

There were 13,193 skin substitute treatment episodes: Apligraf (HML) was used in 4926 (37.3%), Dermagraft (HSL) in 5530 (41.9%), OASIS (SIS) in 2458 (18.6%) and MatriStem (UBM) in 279 (2.1%). The percentage of DFUs that healed at 90 days were: UBM 62%; SIS 63%; HML 58%; and HSL 58%. Over the entire time, UBM was non-inferior to SIS (p<0.001), and either was significantly better than HML or HSL (p<0.005 in all four tests). HML was marginally superior to HSL (p=0.025 unadjusted for multiple testing). Medicare reimbursements for skin substitutes per DFU episode for UBM ($1435 in skin substitutes per episode) and SIS ($1901) appeared to be equivalent to each other, although non-inferiority tests were not significant. Both were less than HML ($5364) or HSL ($14,424) (p<0.0005 in all four tests). HML was less costly than HSL (p<0.0005).

CONCLUSION

Various types of skin substitutes appear to be able to confer important benefits to both patients with DFUs and payers. Analysis of the four skin-substitute types resulted in a demonstration that UBM and SIS were associated with both shorter DFU episode lengths and lower payer reimbursements than HML and HSL, while HML was less costly than HSL but equivalent in healing.

DECLARATION OF INTEREST

MM and NM are health economic consultants who completed and authored this analysis. They have no financial interest in ACell, Inc. Their fees were not contingent on the outcome of this analysis.

Successful wound treatment using negative pressure wound therapy without primary closure in a patient undergoing highly contaminated abdominal surgery

BACKGROUND

The indications for negative pressure wound therapy (NPWT) continue to expand, and NPWT has become a powerful tool for the treatment of interactive wounds. Recently, the use of NPWT over closed incisions has been shown to prevent surgical site infection (SSI) in patients undergoing contaminated or acute care surgery as prophylactic NPWT. In this article, we present our successful experience using NPWT without primary skin closure for wound treatment after a highly contaminated enterological surgery. The procedure we present in this case report is considerably different from the conventional prophylactic NPWT and a novel method in the field of gastrointestinal surgery.

CASE PRESENTATION

A 33-year-old man with Crohn's disease underwent a dirty, infected enterological surgical procedure for the treatment of abdominal wall abscess and multiple fistulas around his colonic stoma. The stoma reconstruction and wound debridement resulted in a broad skin defect, and the incision was strategically left open. In addition to the infected wound condition (class IV), Crohn's disease itself is a risk factor for SSI; consequently, we induced NPWT immediately after the surgery and closed the incision from both ends in a stepwise manner using sutures each time we changed the dressing. This procedure was effective, enabling complete healing and closure at the surgical site on postoperative day 14 without infection or a skin defect.

CONCLUSION

For highly contaminated enterological surgery, purposely leaving the incision open and starting NPWT immediately after the procedure is an effective strategy for early wound closure and the prevention of SSI.

Multi-intervention management of calcific uremic arteriolopathy in 24 patients

Background

Calcific uremic arteriolopathy (CUA), also known as calciphylaxis, is a rare but life-threatening condition predominately occurring in patients with end-stage renal disease on dialysis. In the absence of randomized clinical trials to guide management, clinicians must rely on observational data. We have previously reported the outcomes of our multi-intervention management in seven patients and now present a larger series of patients with extended follow-up.

Methods

We performed a retrospective analysis of all patients diagnosed with CUA at a single academic center between 2008 and 2017. We identified 24 patients including 13 hemodialysis, 8 peritoneal dialysis and 3 predialysis Stage 5 chronic kidney disease patients.

Results

Mean age at diagnosis was 60.5 years (range 35–83) and mean follow-up 30.5 months (range <1–99). Patients were predominately female (71%) and Caucasian (83%) with diabetes mellitus diagnosed in 16 of 24 patients. Fifteen of 24 patients had ulcerating lesions suggestive of advanced disease and 20 of 24 had extensive involvement (bilateral disease or lesion size >5 cm). Treatment consisted of intensive hemodialysis (>20 h per week), sodium thiosulfate, wound care, analgesics and discontinuation of trigger medications including warfarin. Hyperbaric oxygen, cinacalcet, bisphosphonates and vitamin K were used in some cases. Overall 1 year mortality was 41% (9/22) and overall mortality at the end of follow-up was 64% (14/24). Cause of death was felt to be attributable to CUA in only four cases (16.7%). Complete or partial resolution of lesions occurred in 17 of 24 patients. One patient had recurrence of CUA 20 months after initial diagnosis.

Conclusions

Although mortality remains high in this group, direct CUA-attributable mortality is lower than historic reports. We conclude that a multi-intervention approach can be successful in treating a group of patients with severe CUA lesions.

A functional chitosan-based hydrogel as a wound dressing and drug delivery system in the treatment of wound healing

Functional active wound dressings are expected to provide a moist wound environment, offer protection from secondary infections, remove wound exudate and accelerate tissue regeneration, as well as to improve the efficiency of wound healing. Chitosan-based hydrogels are considered as ideal materials for enhancing wound healing owing to their biodegradable, biocompatible, non-toxic, antimicrobial, biologically adhesive, biological activity and hemostatic effects. Chitosan-based hydrogels have been demonstrated to promote wound healing at different wound healing stages, and also can alleviate the factors against wound healing (such as excessive inflammatory and chronic wound infection). The unique biological properties of a chitosan-based hydrogel enable it to serve as both a wound dressing and as a drug delivery system (DDS) to deliver antibacterial agents, growth factors, stem cells and so on, which could further accelerate wound healing. For various kinds of wounds, chitosan-based hydrogels are able to promote the effectiveness of wound healing by modifying or combining with other polymers, and carrying different types of active substances. In this review, we will take a close look at the application of chitosan-based hydrogels in wound dressings and DDS to enhance wound healing.

Potential role of propolis in wound healing: Biological properties and therapeutic activities

Propolis is a resinous mixture that honey bees collect from the tree buds, sap flows, or other botanical sources. The chemical composition of propolis varies and depends on the geographical area, time of collection, seasonality, illumination, altitude, and food availability during propolis exploitation. The goal of this review is to discuss important concepts including mechanisms of action and therapeutic activities of propolis. The PubMed, ScienceDirect, and Cochrane Library databases were searched for the literature published from January the 1st 2000 to October the 1st 2017. Sixteen animals and three clinical studies were included. A quantitative and qualitative review was performed on the clinical trials and the animal studies were comprehensively overviewed. In this study, the clinical trials have been combined and the results were provided as meta-analysis. Propolis is a non-toxic natural product; however some cases of allergy and contact dermatitis to this compound have been described mainly among beekeepers. An important factor in impaired wound healing is biofilm formation; propolis as an anti-microbial agent can reduce biofilm generation and result in accelerated healing processes. Most of the in vivo studies on various wound models suggested the beneficial roles of propolis on experimental wound healing and this has also been approved in the clinical trial studies. However, there is a lack of information concerning, dose, side effects and clinical effectiveness of propolis on wounds. As the effectiveness of propolis between different products is variable, more characterizations should be done and future investigations comparing different propolis based products and characterization of their specific roles on different models of wounds are highly appreciated.

Update on the Role of Infection and Biofilms in Wound Healing: Pathophysiology and Treatment

BACKGROUND

Chronic wounds, and among these infected diabetic foot ulcers, are a worldwide problem. The poor treatment outcomes result in high healthcare costs, amputations, a decreased quality of life, and an increased mortality. These outcomes are influenced by several factors, including biofilm formation. A biofilm consists of pathogenic bacteria that are encased in an exopolysaccharide layer and communicate through secretion of signaling molecules. Bacteria that live in a biofilm are refractory to host responses and treatment.

METHODS

We performed a nonsystematic review of the currently published to-date medical biofilm literature. The review summarizes the evidence of biofilm in chronic wounds, the role of biofilm in wound healing, detection of biofilm, and available antibiofilm treatments. Articles containing basic science and clinical research, as well as systematic reviews, are described and evaluated. The articles have variable levels of evidence. All articles have been peer reviewed and meet the standards of evidence-based medicine.

RESULTS

Both animal and human studies have identified biofilm in chronic wounds and have suggested that healing might be influenced by its presence. A promising development in biofilm detection is rapid molecular diagnostics combined with direct microscopy. This technique, rather than classic culture, might support individualized treatment in the near future. A wide range of treatments for chronic wounds also influence biofilm formation. Several agents that specifically target biofilm are currently being researched.

CONCLUSIONS

Biofilm formation has a substantial role in chronic wounds. Several diagnostic and therapeutic methods against biofilm are currently being developed.

Effects of insulin on wound healing: A review of animal and human evidences

AIMS

Several studies have indicated that insulin that is used in reducing blood glucose is also affective on wound healing by various mechanisms. To understand the outcomes of insulin therapy on wound healing, a meta-analysis and systematic review was performed.

MAIN METHODS

The Cochrane library, PubMed, and Science Direct were searched for the literature published from January the 1st 1990 to September the 30th 2016. Twelve animals and nine clinical studies were included. A quantitative and qualitative review was performed on the clinical trials and the animal studies were comprehensively overviewed. Statistical analysis for development of granulation tissue, microvessel density, and time of healing was conducted in this systematic review.

KEY FINDINGS

The animal studies revealed that treatment with topical insulin lead to faster wound contraction and re-epithelialization. Meta-analysis of wound studies revealed that insulin therapy is significantly favored for growth of granulation tissue. Based on these findings, insulin enhanced development of granulation tissue on day 7 after treatment. The meta-analysis studies indicated significant reduction in time of healing in the patients treated with insulin. These studies also disclosed that the new vessels were observable from five days after injection in the treated group, compared to the control animals that developed significantly at later stage.

SIGNIFICANCE

Insulin is a low cost growth factor and can be considered as a therapeutic agent in wound healing. However, further studies are necessary to gain a better understanding of the role of insulin in wound healing.

[Comparative evaluation of the intensity of reparative processes in the lower extremity soft tissues of diabetic patients receiving local negative pressure wound treatment and standard wound care]

AIM

To study the intensity of soft tissue repair in patients with diabetic foot syndrome (DFS) during local negative pressure wound treatment versus standard wound care.

SUBJECTS AND METHODS

The investigators estimated the clinical (wound sizes, local tissue oxygenation), histological (light microscopy), and immunohistochemical (CD31, CD68, MMP-9, and TIMP-1) markers for reparative processes in patients with DFS during vacuum therapy versus standard wound care. Forty-two patients with the neuropathic and neuroischemic (without critical ischemia) forms of DFS were examined after debridement. In the perioperative period, 21 patients received negative pressure wound therapy and 21 had standard wound care.

RESULTS

During vacuum therapy, the area and depth of wound defects decreased by 19.8±7.8 and 42.8±5.6%, respectively (p=0.002) (as compared to the baseline data). In the control group, these indicators were 17.0±19.4 and 16.6±21.6% (p=0.002). There was a significant intensification of local microhemodynamics according to transcutaneous oximetry readings in the negative pressure wound treatment group. After 9±2 days of treatment, histological examination of granulation tissue revealed a significant reduction in edema, cessation of inflammatory infiltration, and formation of mature granulation tissue in Group 1. Immunohistological examination indicated a more obvious increase in the count of macrophages (CD68 staining) and a significant increment in the number of newly formed vessels, as evidenced by anti-CD31 antibody staining. During the treatment, there was a decline of the expression of MMP-9 and an increase in that of TIMP-1, as compared to those in the control group.

CONCLUSION

The findings are indicative of the enhanced intensity of reparative processes in patients with DFS during vacuum therapy versus standard wound care, resulting in more rapidly decreased wound sizes, increased local microhemodynamics, reduced inflammation, and accelerated wound transition from the inflammatory to the proliferative phase.

The Effectiveness of Negative Pressure Therapy in Diabetic Foot Ulcers with Elevated Protease Activity: A Case Series

Objective: Despite several works have described the usefulness of negative pressure therapy (NPT) in the treatment of diabetic foot ulcers (DFUs), no studies have reported its ability in the proteases modulation in DFUs. The aim of this work was to evaluate the role of NPT as a protease-modulating treatment in DFUs. Approach: We conducted a prospective study of a series of diabetic patients affected by chronic DFUs. Each ulcer was assessed for matrix metalloproteinases (MMPs) activity with a protease status diagnostic test at the baseline and after 2 weeks of NPT. Results: Four patients were included. All patients had type 2 diabetes with a disease duration of ≈20 years. A1c was 79.5 ± 15.3 mmol/mol. Ulcer area was >5 cm2 in all cases. All wounds showed elevated protease activity (EPA) at the baseline. After 2 weeks, all patients showed a normalization of MMPs activity. Innovation: NPT showed its effectiveness in the reduction of EPA in chronic DFUs. Conclusion: This study confirms the role of NPT in the positive modulation of protease activity also in chronic DFUs.