Recent insights into the causes of chronic leg ulceration in venous diseases and implications on other types of chronic wounds

Wound Bed Preparation and Treatment Modalities

Wound healing is a highly complex natural process, and its failure results in chronic wounds. The causes of delayed wound healing include patient-related and local wound factors. The main local impediments to delayed healing are the presence of nonviable tissue, excessive inflammation, infection, and moisture imbalance. For wounds that can be healed with adequate blood supply, a stepwise approach to identify and treat these barriers is termed wound bed preparation. Currently, a combination of patient-related and local factors, including wound debridement, specialty dressings, and advanced technologies, is available and successfully used to facilitate the healing process.

Biomaterials-Based Strategies to Enhance Angiogenesis in Diabetic Wound Healing

Amidst the present healthcare issues, diabetes is unique as an emerging class of affliction with chronicity in a majority of the population. To check and control its effects, there have been huge turnover and constant development of management strategies, and though a bigger part of the health care area is involved in achieving its control and the related issues such as the effect of diabetes on wound healing and care and many of the works have reached certain successful outcomes, still there is a huge lack in managing it, with maximum effect yet to be attained. Studying pathophysiology and involvement of various treatment options, such as tissue engineering, application of hydrogels, drug delivery methods, and enhancing angiogenesis, are at constantly developing stages either direct or indirect. In this review, we have gathered a wide field of information and different new therapeutic methods and targets for the scientific community, paving the way toward more settled ideas and research advances to cure diabetic wounds and manage their outcomes.

Bioarchitectural Design of Bioactive Biopolymers: Structure-Function Paradigm for Diabetic Wound Healing

Chronic wounds such as diabetic ulcers are a major complication in diabetes caused by hyperglycemia, prolonged inflammation, high oxidative stress, and bacterial bioburden. Bioactive biopolymers have been found to have a biological response in wound tissue microenvironments and are used for developing advanced tissue engineering strategies to enhance wound healing. These biopolymers possess innate bioactivity and are biodegradable, with favourable mechanical properties. However, their bioactivity is highly dependent on their structural properties, which need to be carefully considered while developing wound healing strategies. Biopolymers such as alginate, chitosan, hyaluronic acid, and collagen have previously been used in wound healing solutions but the modulation of structural/physico-chemical properties for differential bioactivity have not been the prime focus. Factors such as molecular weight, degree of polymerization, amino acid sequences, and hierarchical structures can have a spectrum of immunomodulatory, anti-bacterial, and anti-oxidant properties that could determine the fate of the wound. The current narrative review addresses the structure-function relationship in bioactive biopolymers for promoting healing in chronic wounds with emphasis on diabetic ulcers. This review highlights the need for characterization of the biopolymers under research while designing biomaterials to maximize the inherent bioactive potency for better tissue regeneration outcomes, especially in the context of diabetic ulcers.

Sub-ulcer Foam Sclerotherapy in Patients with Venous Leg Ulcer, Analysis and Technical Aspects of 134 Consecutive Patients

OBJECTIVE

For this retrospective study, we analyzed the sub-ulcer foam sclerotherapy technique in patients with venous leg ulcer (VLU).

METHODS

This study included 134 patients treated with sub-ulcer foam sclerotherapy at the Oulu University Hospital vascular outpatient clinic from January 2012 to December 2021. All included patients received sub-ulcer foam sclerotherapy as part of the treatment strategy for superficial venous insufficiency. Compression therapy and local wound care were organized for VLU treatment. A follow-up visit was scheduled for one month after the sub-ulcer foam sclerotherapy. Change in ulcer size, local (skin necrosis, infection) or systemic (deep vein thrombosis, pulmonary embolism) complications, and time to ulcer healing were monitored. The occurrence of major limb-related complications (amputation, surgical revision) was monitored for one year postoperatively.

RESULTS

One month after sub-ulcer treatment, ulcers were smaller or completely healed in 108 (81%) patients. Ulcer healing was completed in 123 (92%) patients at one year and 131 (98%) patients at two years. Complications were recorded in four (3%) patients, three (2%) who were diagnosed with erysipelas requiring antibiotic treatment and one (1%) patient diagnosed with local dermatitis. During the one-year follow-up, no major limb-related complications (surgical revisions or amputations) arose.

CONCLUSIONS

Sub-ulcer foam sclerotherapy may be a feasible addition to superficial vein reflux elimination in patients with VLU and a low risk for complications.

Regulation of inflammation during wound healing: the function of mesenchymal stem cells and strategies for therapeutic enhancement

A wound takes a long time to heal and involves several steps. Following tissue injury, inflammation is the primary cause of tissue regeneration and repair processes. As a result, the pathophysiological processes involving skin damage, healing, and remodeling depend critically on the control of inflammation. The fact that it is a feasible target for improving the prognosis of wound healing has lately become clear. Mesenchymal stem cells (MSCs) are an innovative and effective therapeutic option for wound healing due to their immunomodulatory and paracrine properties. By controlling the inflammatory milieu of wounds through immunomodulation, transplanted MSCs have been shown to speed up the healing process. In addition to other immunomodulatory mechanisms, including handling neutrophil activity and modifying macrophage polarization, there may be modifications to the activation of T cells, natural killer (NK) cells, and dendritic cells (DCs). Furthermore, several studies have shown that pretreating MSCs improves their ability to modulate immunity. In this review, we summarize the existing knowledge about how MSCs influence local inflammation in wounds by influencing immunity to facilitate the healing process. We also provide an overview of MSCs optimizing techniques when used to treat wounds.

Compression therapy for NHS inpatients with leg ulcers: a literature review

OBJECTIVE

Leg ulcers are common, distressing and painful for patients, and are a significant financial burden to healthcare providers. Compression therapy is the mainstay of treatment for venous leg ulceration. Several studies have evaluated leg ulcer management and compression therapy in the community. However, little is known about the prevalence of leg ulceration and use of compression therapy in acute hospitals. The aim of this study was to explore the published literature on the use of compression therapy for inpatients with leg ulcers in UK National Health Service hospital settings.

METHOD

A literature search was undertaken to identify published papers reporting on inpatient leg ulcer populations and the use of compression therapy in hospitals using the following databases: CINAHL, MEDLINE Complete, Embase and PubMed.

RESULTS

The literature review identified 364 articles, of which three met the eligibility criteria. These studies reported on the prevalence of leg ulceration, the number of Doppler assessments conducted for patients and the use of compression therapy.

CONCLUSION

This review confirmed a lack of information on the prevalence of hospital inpatients with leg ulcers, and identified the need to conduct prevalence audits, establish leg ulcer services to streamline inpatient leg ulcer care and provide staff and patient education programmes.

Inflammasome Coordinates Senescent Chronic Wound Induced by Thalassophryne nattereri Venom

Thalassophryne nattereri toadfish (niquim) envenomation, common in the hands and feet of bathers and fishermen in the north and northeast regions of Brazil, is characterized by local symptoms such as immediate edema and intense pain. These symptoms progress to necrosis that lasts for an extended period of time, with delayed healing. Wound healing is a complex process characterized by the interdependent role of keratinocytes, fibroblasts, and endothelial and innate cells such as neutrophils and macrophages. Macrophages and neutrophils are actively recruited to clear debris during the inflammatory phase of wound repair, promoting the production of pro-inflammatory mediators, and in the late stage, macrophages promote tissue repair. Our hypothesis is that injury caused by T. nattereri venom (VTn) leads to senescent wounds. In this study, we provide valuable information about the mechanism(s) behind the dysregulated inflammation in wound healing induced by VTn. We demonstrate in mouse paws injected with the venom the installation of γH2AX/p16^Ink4a-dependent senescence with persistent neutrophilic inflammation in the proliferation and remodeling phases. VTn induced an imbalance of M1/M2 macrophages by maintaining a high number of TNF-α-producing M1 macrophages in the wound but without the ability to eliminate the persistent neutrophils. Chronic neutrophilic inflammation and senescence were mediated by cytokines such as IL-1α and IL-1β in a caspase-1- and caspase-11-dependent manner. In addition, previous blocking with anti-IL-1α and anti-IL-β neutralizing antibodies and caspase-1 (Ac YVAD-CMK) and caspase-11 (Wedelolactone) inhibitors was essential to control the pro-inflammatory activity of M1 macrophages induced by VTn injection, skewing towards an anti-inflammatory state, and was sufficient to block neutrophil recruitment and senescence.

Recent trends in diabetic wound healing with nanofibrous scaffolds

There is an emphasis in this review on nanofibrous scaffolds (NFSs) in diabetic wound healing, as well as their mechanisms and recent advancements. Diabetes-related complex wounds pose an important problem to humanity, due to the fact that their chronic nature can lead to serious complications including sepsis and amputations. Despite the fact that there are certain therapy options available for diabetic wound healing, these options are either ineffective or intrusive, making clinical intervention difficult. Clinical research is also challenged by the emergence of bacterial resistance to standard antibiotics. However, research into nanotechnology, in particular NFSs, is growing swiftly and has a positive impact on the treatment of diabetic wounds. For instance, SpinCare™, developed by Nanomedic Technologies Ltd, has successfully finished clinical testing and can re-epithelialize second-degree burns and chronic diabetic wounds in 7 and 14 days, respectively. In this review, we discussed homologous studies as well as other recent research studies on diabetic wound healing using NFSs.

Biomedical materials for wound dressing: recent advances and applications

Wound healing is vital to maintain the physiological functions of the skin. The most common treatment is the use of a dressing to cover the wound and reduce infection risk and the rate of secondary injuries. Modern wound dressings have been the top priority choice for healing various types of wounds owing to their outstanding biocompatibility and biodegradability. In addition, they also maintain temperature and a moist environment, aid in pain relief, and improve hypoxic environments to stimulate wound healing. Due to the different types of wounds, as well as the variety of advanced wound dressing products, this review will provide information on the clinical characteristics of the wound, the properties of common modern dressings, and the in vitro, in vivo as well as the clinical trials on their effectiveness. The most popular types commonly used in producing modern dressings are hydrogels, hydrocolloids, alginates, foams, and films. In addition, the review also presents the polymer materials for dressing applications as well as the trend of developing these current modern dressings to maximize their function and create ideal dressings. The last is the discussion about dressing selection in wound treatment and an estimate of the current development tendency of new materials for wound healing dressings.

Integrated network pharmacology and experimental validation to explore the mechanisms underlying naringenin treatment of chronic wounds

Naringenin is a citrus flavonoid with various biological functions and a potential therapeutic agent for skin diseases, such as UV radiation and atopic dermatitis. The present study investigates the therapeutic effect and pharmacological mechanism of naringenin on chronic wounds. Using network pharmacology, we identified 163 potential targets and 12 key targets of naringenin. Oxidative stress was confirmed to be the main biological process modulated by naringenin. The transcription factor p65 (RELA), alpha serine/threonine-protein kinase (AKT1), mitogen-activated protein kinase 1 (MAPK1) and mitogen-activated protein kinase 3 (MAPK3) were identified as common targets of multiple pathways involved in treating chronic wounds. Molecular docking verified that these four targets stably bound naringenin. Naringenin promoted wound healing in mice in vivo by inhibiting wound inflammation. Furthermore, in vitro experiments showed that a low naringenin concentration did not significantly affect normal skin cell viability and cell apoptosis; a high naringenin concentration was cytotoxic and reduced cell survival by promoting apoptosis. Meanwhile, comprehensive network pharmacology, molecular docking and in vivo and in vitro experiments revealed that naringenin could treat chronic wounds by alleviating oxidative stress and reducing the inflammatory response. The underlying mechanism of naringenin in chronic wound therapy involved modulating the RELA, AKT1 and MAPK1/3 signalling pathways to inhibit ROS production and inflammatory cytokine expression.

Acute Inflammation in Tissue Healing

There are well-established links between acute inflammation and successful tissue repair across evolution. Innate immune reactions contribute significantly to pathogen clearance and activation of subsequent reparative events. A network of molecular and cellular regulators supports antimicrobial and tissue repair functions throughout the healing process. A delicate balance must be achieved between protection and the potential for collateral tissue damage associated with overt inflammation. In this review, we summarize the contributions of key cellular and molecular components to the acute inflammatory process and the effective and timely transition toward activation of tissue repair mechanisms. We further discuss how the disruption of inflammatory responses ultimately results in chronic non-healing injuries.

Centella asiatica extract in carboxymethyl cellulose at its optimal concentration improved wound healing in mice model

Centella asiatica (C. asiatica) has reported to be one of the traditional herbal remedies, whereas poor water solubility leads to lower bioavailability thereby affecting it remedial efficacy. Therefore, we aimed to evaluate its efficacy through increased bioavailability by using high viscosity Carboxymethyl Cellulose (CMC) as solvent on methanol-based extract on wound healing, in vivo. The preparation was applied as 0.0% (control, CMC alone), 0.25. 0.5 and 1% concentrations of extract of C. asiatica. We evaluated the efficiency of preparations on wound healing progression as progression of wound contraction, tissue proliferation and cells deposition, and relative level of gene expression for genes associated with wound healing. The results showed that 0.5% extract in CMC had significantly higher (P < 0.05) wound contraction than control and other concentrations. The level tissue deposition and the infiltration of polymorphonuclear cells in groups treated with 0.5 % concentration preparation were higher than that other treatments and control. Similarly, the relative level of gene expression in 0.5% concentration treated group were statistically significantly higher (P < 0.05) than that of control. It is believed that the lower concentration of the extract would have lessor effect on wound healing, whereas higher concertation would be interfering the optimal inflammatory tissue deposition; and there by negatively affecting wound healing. The results indicated that C. asiatica can be optimally used at 0.5 % of extract in CMC for wound healing as indicated by speeding the progression of wound closure and by increasing the expression of collagen II and III together with reducing the expression of TGFβ1. However, higher concentrations of the crude extract of C. asiatica could paradoxically resulting in undesired effects. It is recommended that further evaluation should be performed on wider scale and the economic feasibility evaluation should be performed.

Homocysteine and Inflammatory Cytokines in the Clinical Assessment of Infection in Venous Leg Ulcers

Inflammation and biofilm-associated infection are common in chronic venous leg ulcers (VU), causing deep pain and delayed healing. Albeit important, clinical markers and laboratory parameters for identifying and monitoring persistent VU infections are limited. This study analyzed 101 patients with infected (IVU) and noninfected VUs (NVU). Clinical data were collected in both groups. The serum homocysteine (Hcys) and inflammatory cytokines from the wound fluid were measured. In addition, microbial identification, antibiotic susceptibility, and biofilm production were examined. IVU were 56 (55.4%) while NVU were 45 (44.5%). IVUs showed a significant increase in the wound's size and depth compared to NVUs. In addition, significantly higher levels of interleukin (IL)-6, IL-10, IL17A, and tumor necrosis factor-alpha (TNF-α) were found in patients with IVUs compared to those with NVUs. Notably, hyperhomocysteinemia (HHcy) was significantly more common in patients with IVUs than NVUs. A total of 89 different pathogens were identified from 56 IVUs. Gram-negative bacteria were 51.7%, while the Gram-positives were 48.3%. At the species level, Staphylococcus aureus was the most common isolate (43.8%), followed by Pseudomonas aeruginosa (18.0%). Multidrug-resistant organisms (MDROs) accounted for 25.8% of the total isolates. Strong biofilm producers (SBPs) (70.8%) were significantly more abundant than weak biofilm producers (WBP) (29.2%) in IVUs. SBPs were present in 97.7% of the IVUs as single or multispecies infections. Specifically, SBPs were 94.9% for S. aureus, 87.5% for P. aeruginosa, and 28.6% for Escherichia coli. In IVU, the tissue microenvironment and biofilm production can support chronic microbial persistence and a most severe clinical outcome even in the presence of an intense immune response, as shown by the high levels of inflammatory molecules. The measurement of local cytokines in combination with systemic homocysteine may offer a novel set of biomarkers for the clinical assessment of IVUs caused by biofilm-producing bacteria.

Bioactive Materials Promote Wound Healing through Modulation of Cell Behaviors

Skin wound repair is a multistage process involving multiple cellular and molecular interactions, which modulate the cell behaviors and dynamic remodeling of extracellular matrices to maximize regeneration and repair. Consequently, abnormalities in cell functions or pathways inevitably give rise to side effects, such as dysregulated inflammation, hyperplasia of nonmigratory epithelial cells, and lack of response to growth factors, which impedes angiogenesis and fibrosis. These issues may cause delayed wound healing or even non-healing states. Current clinical therapeutic approaches are predominantly dedicated to preventing infections and alleviating topical symptoms rather than addressing the modulation of wound microenvironments to achieve targeted outcomes. Bioactive materials, relying on their chemical, physical, and biological properties or as carriers of bioactive substances, can affect wound microenvironments and promote wound healing at the molecular level. By addressing the mechanisms of wound healing from the perspective of cell behaviors, this review discusses how bioactive materials modulate the microenvironments and cell behaviors within the wounds during the stages of hemostasis, anti-inflammation, tissue regeneration and deposition, and matrix remodeling. A deeper understanding of cell behaviors during wound healing is bound to promote the development of more targeted and efficient bioactive materials for clinical applications.

Leg ulcer service provision in NHS hospitals

AIM

To explore the service provision for compression therapy for inpatients with leg ulcers in UK hospitals.

METHODS

An online survey was carried out to explore the service provision in hospital settings. It was distributed to Wounds UK National Conference delegates and to wound care specialist groups using social media.

RESULTS

The authors received 101 responses from health professionals in the UK. Of these, 67.3% reported there was no dedicated service for inpatients with leg ulceration and only 32% said compression therapy was provided in their hospitals.

CONCLUSION

This survey confirmed there is a significant shortfall in care provision for patients with leg ulcers in secondary care and highlighted the wide variations in service delivery in hospitals. Further research is needed to understand the reasons for these variations.

Biophysical Characterization of a Novel Tri-Layer Placental Allograft Membrane

Objective: Placental tissues, including membranes composed of amnion and chorion, are promising options for the treatment of chronic wounds. Amnion and chorion contain multiple extracellular matrix (ECM) proteins and a multitude of growth factors and cytokines that, when used clinically, assist in the progression of difficult to heal wounds through restoration of a normal healing process. The objective of this study was to characterize the in vitro physical and biological properties of a dehydrated tri-layer placental allograft membrane (TPAM) consisting of a chorion layer sandwiched between two layers of amnion. Approach: Mechanical properties were evaluated by mechanical strength and enzyme degradation assays. The ECM composition of TPAM membranes was evaluated by histological staining while growth factors and cytokine presence was evaluated by a multiplex enzyme-linked immunosorbent assay. Proliferation, migration, and ECM secretion assays were performed with fibroblasts. Immunomodulatory properties were assessed by a pro-inflammatory cytokine reduction assay while the macrophage phenotype was determined by quantifying the ratio of M1 versus M2 secreted factors. Results: The unique three-layer construction improves mechanical handling properties over single- and bi-layer membranes. Results demonstrate that TPAM is rich in ECM proteins, growth factors, cytokines, and tissue inhibitors of metalloproteinases, and favorably influences fibroblast migration, proliferation, and ECM secretion when compared to negative controls. Furthermore, after processing and preservation, these membranes maintain their intrinsic immunomodulatory properties with the ability to suppress pro-inflammatory processes and modulate the M1 and M2 macrophage phenotype toward a pro-regenerative profile when compared to a negative control. Innovation: This is the first study to characterize both the biophysical and biological properties of a tri-layer placental membrane. Conclusion: This work demonstrates that TPAM has improved handling characteristics over single- and bi-layer membranes, stimulates pro-healing cellular responses, and advantageously modulates inflammatory responses, altogether making this scaffold a promising option for treating wounds, especially those that are complex or difficult to heal.

Arginase Signalling as a Key Player in Chronic Wound Pathophysiology and Healing

Arginase (ARG) represents an important evolutionarily conserved enzyme that is expressed by multiple cell types in the skin. Arg acts as the mediator of the last step of the urea cycle, thus providing protection against excessive ammonia under homeostatic conditions through the production of L-ornithine and urea. L-ornithine represents the intersection point between the ARG-dependent pathways and the urea cycle, therefore contributing to cell detoxification, proliferation and collagen production. The ARG pathways help balance pro- and anti-inflammatory responses in the context of wound healing. However, local and systemic dysfunctionalities of the ARG pathways have been shown to contribute to the hindrance of the healing process and the occurrence of chronic wounds. This review discusses the functions of ARG in macrophages and fibroblasts while detailing the deleterious implications of a malfunctioning ARG enzyme in chronic skin conditions such as leg ulcers. The review also highlights how ARG links with the microbiota and how this impacts on infected chronic wounds. Lastly, the review depicts chronic wound treatments targeting the ARG pathway, alongside future diagnosis and treatment perspectives.

PRDX4 Improved Aging-Related Delayed Wound Healing in Mice

Aging-related delayed wound healing is an issue of concern worldwide. Oxidative stress is involved in wound healing. Antioxidative enzymes have various roles in this process. PRDX4, a member of the PRDX family, is upregulated after injury. To investigate the effects of PRDX4 on aging-related wound healing, we subjected C57BL/6J (wild-type), human Prdx4‒transgenic (i.e., hPrdx4^+/+), Prdx4-knockout (i.e., Prdx4^-/y) mice of three age groups (young, adult, and aged) to skin wound formation. The overexpression of PRDX4 accelerated wound healing in adult and aged mice but not in young mice. Aged hPrdx4^+/+ mice showed reduced oxidative stress and inflammation, lower numbers of neutrophils, increased macrophage infiltration, increased angiogenesis, and increased GF levels. The granulation tissue of adult and aged hPrdx4^+/+ mice was richer in fibroblasts than that in the matched wild-type mice. PRDX4 deficiency was associated with mortality in adult and aged mice. In vitro, the overexpression of PRDX4 promoted the proliferation and migration of fibroblasts derived from adult or aged mice and made fibroblasts more resistant to the cytotoxicity of hydrogen peroxide. PRDX4 is essential for wound healing and can improve the healing process from multiple aspects, suggesting that it may be very beneficial to wound treatment, especially for the elderly.

Electrospun PCL/PLA Scaffolds Are More Suitable Carriers of Placental Mesenchymal Stromal Cells Than Collagen/Elastin Scaffolds and Prevent Wound Contraction in a Mouse Model of Wound Healing

Mesenchymal stem/stromal cells (MSCs) exert beneficial effects during wound healing, and cell-seeded scaffolds are a promising method of application. Here, we compared the suitability of a clinically used collagen/elastin scaffold (Matriderm) with an electrospun Poly(ε-caprolactone)/poly(l-lactide) (PCL/PLA) scaffold as carriers for human amnion-derived MSCs (hAMSCs). We created an epidermal-like PCL/PLA scaffold and evaluated its microstructural, mechanical, and functional properties. Sequential spinning of different PCL/PLA concentrations resulted in a wide-meshed layer designed for cell-seeding and a dense-meshed layer for apical protection. The Matriderm and PCL/PLA scaffolds then were seeded with hAMSCs, with or without Matrigel coating. The quantity and quality of the adherent cells were evaluated in vitro. The results showed that hAMSCs adhered to and infiltrated both scaffold types but on day 3, more cells were observed on PCL/PLA than on Matriderm. Apoptosis and proliferation rates were similar for all carriers except the coated Matriderm, where apoptotic cells were significantly enhanced. On day 8, the number of cells decreased on all carrier types except the coated Matriderm, which had consistently low cell numbers. Uncoated Matriderm had the highest percentage of proliferative cells and lowest apoptosis rate of all carrier types. Each carrier also was topically applied to skin wound sites in a mouse model and analyzed in vivo over 14 days via optical imaging and histological methods, which showed detectable hAMSCs on all carrier types on day 8. On day 14, all wounds exhibited newly formed epidermis, and all carriers were well-integrated into the underlying dermis and showing signs of degradation. However, only wounds treated with uncoated PCL/PLA maintained a round appearance with minimal contraction. Overall, the results support a 3-day in vitro culture of scaffolds with hAMSCs before wound application. The PCL/PLA scaffold showed higher cell adherence than Matriderm, and the effect of the Matrigel coating was negligible, as all carrier types maintained sufficient numbers of transplanted cells in the wound area. The anti-contractive effects of the PCL/PLA scaffold offer potential new therapeutic approaches to wound care.

Modern view on the therapy of chronic venous insufficiency with micronized purified flavonoid fraction

The high prevalence of varicose veins has been established in numerous population studies. Currently, guidelines have been developed for the treatment of patients with varicose veins for various stages of chronic venous insufficiency. Nevertheless, despite the use of modern drugs, leg compression, surgical and other interventions, it is not possible to completely reverse the symptoms of venous insufficiency. The article is devoted to the analysis of micronized flavonoid purified fraction. The development of modern drugs for chronic venous diseases is an important direction in medicine. The creation of a drug pool manufactured InRussiais a priority in the development of the country’s pharmaceutical industry. The review presents data on the study of Detravenol (Russia), which is a combination of diosmin and hesperidin (micronized purified flavonoid fraction).

Ulcers in leprosy patients, an unrecognized clinical manifestation: a report of 8 cases

Background

Leprosy is a chronic granulomatous infection caused by Mycobacterium leprae. It is a polymorphic disease with a wide range of cutaneous and neural manifestations. Ulcer is not a common feature in leprosy patients, except during reactional states, Lucio’s phenomenon (LP), or secondary to neuropathies.

Cases presentation

We report eight patients with multibacillary leprosy who presented specific skin ulcers as part of their main leprosy manifestation. Ulcers were mostly present on lower limbs (eight patients), followed by the upper limbs (three patients), and the abdomen (one patient). Mean time from onset of skin ulcers to diagnosis of leprosy was 17.4 months: all patients were either misdiagnosed or had delayed diagnosis, with seven of them presenting grade 2 disability by the time of the diagnosis. Reactional states, LP or neuropathy as potential causes of ulcers were ruled out. Biopsy of the ulcer was available in seven patients: histopathology showed mild to moderate lympho-histiocytic infiltrate with vacuolized histiocytes and intact isolated and grouped acid-fast bacilli. Eosinophils, vasculitis, vasculopathy or signs of chronic venous insufficiency were not observed. Skin lesions improved rapidly after multidrug therapy, without any concomitant specific treatment for ulcers.

Conclusions

This series of cases highlights the importance of recognizing ulcers as a specific cutaneous manifestation of leprosy, allowing diagnosis and treatment of the disease, and therefore avoiding development of disabilities and persistence of the transmission chain of M. leprae.

Diabetic foot ulcer treatment with focused shockwave therapy: two multicentre, prospective, controlled, double-blinded, randomised phase III clinical trials

OBJECTIVE

To investigate the efficacy of focused extracorporeal shockwave therapy (ESWT) as an adjunctive treatment for neuropathic diabetic foot ulcers (DFU) (1A or 2A on the University of Texas grading scheme), compared with sham treatment.

METHOD

We performed two multicentre, randomised, sham-controlled, double-blinded, phase III clinical trials using focused ESWT compared with sham examining DFUs that did not reduce in volume by ≥50% over 2 weeks' standard treatment immediately prior to randomisation. Patients were enrolled into the trials and randomised for either standard care and focused ESWT (pulsed acoustic cellular expression. dermaPACE System, SANUWAVE Health Inc.) active therapy, or standard care and sham therapy. Both active and sham therapy were administered four times in 2 weeks in study 1 and a maximum of eight times over 12 weeks in study 2. Standard care continued in both studies throughout the 12-week treatment phase. The proportion of DFUs that closed completely by 12, 20 and 24 weeks was measured.

RESULTS

The two studies evaluated 336 patients; 172 patients treated with active therapy and 164 managed with a sham device. The demographic characteristics of patients in the two arms of both studies were balanced and statistical comparison of the two studies justified pooling datasets for analysis. Statistically significantly more DFU healed at 20 (35.5% versus 24.4%; p=0.027) and 24 weeks (37.8% versus 26.2%; p=0.023) in the active treatment arm compared with the sham-controlled arm. At 12 weeks the active therapy arm trended to significance (22.7% versus 18.3%).

CONCLUSION

The outcome of these two trials suggests that ESWT is an effective therapeutic modality in combination with standard care for neuropathic DFU that do not respond to standard care alone.

Cell salvage in acute and chronic wounds: a potential treatment strategy. Experimental data and early clinical results

On 9 May 2018, the authors took part in a closed panel discussion on the impact of cell salvage in acute and chronic wounds. The goal was to deliberate the possible use of plurogel micelle matrix (PMM) as a new treatment strategy for wound healing and the authors openly shared their experiences, thoughts, experimental data and early clinical results. The outcome of the panel discussion has been abridged in this paper. The cell membrane consists of a lipid bilayer, which provides a diffusion barrier separating the inside of a cell from its environment. Cell membrane injury can result in acute cellular necrosis when defects are too large and cannot be resealed. There is a potential hazard to the body when these dying cells release endogenous alarm signals referred to as 'damage (or danger) associated molecular patterns' (DAMPs), which trigger the innate immune system and modulate inflammation. Cell salvage by membrane resealing is a promising target to ensure the survival of the individual cell and prevention of further tissue degeneration by inflammatory processes. Non-ionic surfactants such as poloxamers, poloxamines and PMM have the potential to resuscitate cells by inserting themselves into damaged membranes and stabilising the unstable portions of the lipid bilayers. The amphiphilic properties of these molecules are amenable to insertion into cell wall defects and so can play a crucial, reparative role. This new approach to cell rescue or salvage has gained increasing interest as several clinical conditions have been linked to cell membrane injury via oxidative stress-mediated lipid peroxidation or thermal disruption. The repair of the cell membrane is an important step in salvaging cells from necrosis to prevent further tissue degeneration by inflammatory processes. This is applicable to acute burns and chronic wounds such as diabetic foot ulcers (DFUs), chronic venous leg ulcers (VLUs), and pressure ulcers (PUs). Experimental data shows that PMM is biocompatible and able to insert itself into damaged membranes, salvaging their barrier function and aiding cell survival. Moreover, the six case studies presented in this paper reveal the potential of this treatment strategy.

Subfascial endoscopic perforator surgery (SEPS) for treating venous leg ulcers

BACKGROUND

Venous leg ulcers are complex, costly, and their prevalence is expected to increase as populations age. Venous congestion is a possible cause of venous leg ulcers, which subfascial endoscopic perforator surgery (SEPS) attempts to address by removing the connection between deep and superficial veins (perforator veins). The effectiveness of SEPS in the treatment of venous leg ulcers, however, is unclear.

OBJECTIVES

To assess the benefits and harms of subfascial endoscopic perforator surgery (SEPS) for the treatment of venous leg ulcers.

SEARCH METHODS

In March 2018 we searched the Cochrane Wounds Specialised Register; the Cochrane Central Register of Controlled Trials (CENTRAL); Ovid MEDLINE (including In-Process & Other Non-Indexed Citations); Ovid Embase and EBSCO CINAHL Plus. We also searched clinical trials registries for ongoing and unpublished studies, and scanned reference lists of included studies as well as reviews, meta-analyses and health technology reports to identify additional studies. There were no restrictions with respect to language, date of publication or study setting.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) of interventions that examined the use of SEPS independently or in combination with another intervention for the treatment of venous leg ulcers.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies for inclusion, extracted data, assessed risk of bias, and assessed the certainty of evidence using the GRADE approach.

MAIN RESULTS

We included four RCTs with a total of 322 participants. There were three different comparators: SEPS plus compression therapy versus compression therapy (two trials); SEPS versus the Linton procedure (a type of open surgery) (one trial); and SEPS plus saphenous surgery versus saphenous surgery (one trial). The age range of participants was 30 to 82, with an equal spread of male and female participants. All trials were conducted in hospital settings with varying durations of follow-up, from 18 months to 6 years. One trial included participants who had both healed and active ulcers, with the rest including only participants with active ulcers.There was the potential for reporting bias in all trials and performance bias and detection bias in three trials. Participants in the fourth trial received one of two surgical procedures, and this study was at low risk of performance bias and detection bias.SEPS + compression therapy versus compression therapy (2 studies; 208 participants)There may be an increase in the proportion of healed ulcers at 24 months in people treated with SEPS and compression therapy compared with compression therapy alone (risk ratio (RR) 1.17, 95% confidence interval (CI) 1.03 to 1.33; 1 study; 196 participants); low-certainty evidence (downgraded twice, once for risk of bias and once for imprecision).It is uncertain whether SEPS reduces the risk of ulcer recurrence at 24 months (RR 0.85, 95% CI 0.26 to 2.76; 2 studies; 208 participants); very low-certainty evidence (downgraded three times, twice for very serious imprecision and once for risk of bias).The included trials did not measure or report the following outcomes; time to complete healing, health-related quality of life (HRQOL), adverse events, pain, duration of hospitalisation, and district nursing care requirements.SEPS versus Linton approach (1 study; 39 participants)It is uncertain whether there is a difference in ulcer healing at 24 months between participants treated with SEPS and those treated with the Linton procedure (RR 0.95, 95% CI 0.83 to 1.09; 1 study; 39 participants); very low-certainty evidence (downgraded three times, twice for very serious imprecision and once for risk of bias).It is also uncertain whether there is a difference in risk of recurrence at 60 months: (RR 0.47, 95% CI 0.10 to 2.30; 1 study; 39 participants); very low-certainty evidence (downgraded three times, twice for very serious imprecision and once for risk of bias).The Linton procedure is possibly associated with more adverse events than SEPS (RR 0.04, 95% CI 0.00 to 0.60; 1 study; 39 participants); very low-certainty evidence (downgraded three times, twice for very serious imprecision and once for risk of bias).The outcomes time to complete healing, HRQOL, pain, duration of hospitalisation and district nursing care requirements were either not measured, reported or data were not available for analysis.SEPS + saphenous surgery versus saphenous surgery (1 study; 75 participants)It is uncertain whether there is a difference in ulcer healing at 12 months between participants treated with SEPS and saphenous surgery versus those treated with saphenous surgery alone (RR 0.96, 95% CI 0.64 to 1.43; 1 study; 22 participants); very low certainty evidence (downgraded three times, twice for very serious imprecision and once for high risk of reporting bias).It is also uncertain whether there is a difference in the risk of recurrence at 12 months: (RR 1.03, 95% CI 0.15 to 6.91; 1 study; 75 participants); very low certainty evidence (downgraded three times, twice for very serious imprecision and once for high risk of reporting bias).Finally, we are uncertain whether there is an increase in adverse events in the SEPS group (RR 2.05, 95% CI 0.86 to 4.90; 1 study; 75 participants); very low certainty evidence (downgraded three times, twice for very serious imprecision and once for high risk of reporting bias).The outcomes time to complete healing, HRQOL, serious adverse events, pain, duration of hospitalisation, and district nursing care requirements were either not measured, reported or data were not available for analysis.

AUTHORS' CONCLUSIONS

The role of SEPS for the treatment of venous leg ulcers remains uncertain. Only low or very low-certainty evidence was available for inclusion. Due to small sample sizes and risk of bias in the included studies, we were unable to determine the potential benefits and harms of SEPS for this purpose. Only four studies met our inclusion criteria, three were very small, and one was poorly reported. Further high-quality studies addressing the use of SEPS in venous leg ulcer management are likely to change the conclusions of this review.

Wound Healing: A Cellular Perspective

Wound healing is one of the most complex processes in the human body. It involves the spatial and temporal synchronization of a variety of cell types with distinct roles in the phases of hemostasis, inflammation, growth, re-epithelialization, and remodeling. With the evolution of single cell technologies, it has been possible to uncover phenotypic and functional heterogeneity within several of these cell types. There have also been discoveries of rare, stem cell subsets within the skin, which are unipotent in the uninjured state, but become multipotent following skin injury. Unraveling the roles of each of these cell types and their interactions with each other is important in understanding the mechanisms of normal wound closure. Changes in the microenvironment including alterations in mechanical forces, oxygen levels, chemokines, extracellular matrix and growth factor synthesis directly impact cellular recruitment and activation, leading to impaired states of wound healing. Single cell technologies can be used to decipher these cellular alterations in diseased states such as in chronic wounds and hypertrophic scarring so that effective therapeutic solutions for healing wounds can be developed.

Proteolytic signatures define unique thrombin-derived peptides present in human wound fluid in vivo

The disease burden of failing skin repair and non-healing ulcers is extensive. There is an unmet need for new diagnostic approaches to better predict healing activity and wound infection. Uncontrolled and excessive protease activity, of endogenous or bacterial origin, has been described as a major contributor to wound healing impairments. Proteolytic peptide patterns could therefore correlate and “report” healing activity and infection. This work describes a proof of principle delineating a strategy by which peptides from a selected protein, human thrombin, are detected and attributed to proteolytic actions. With a particular focus on thrombin-derived C-terminal peptides (TCP), we show that distinct peptide patterns are generated in vitro by the human S1 peptidases human neutrophil elastase and cathepsin G, and the bacterial M4 peptidases Pseudomonas aeruginosa elastase and Staphylococcus aureus aureolysin, respectively. Corresponding peptide sequences were identified in wound fluids from acute and non-healing ulcers, and notably, one peptide, FYT21 (FYTHVFRLKKWIQKVIDQFGE), was only present in wound fluid from non-healing ulcers colonized by P. aeruginosa and S. aureus. Our result is a proof of principle pointing at the possibility of defining peptide biomarkers reporting distinct proteolytic activities, of potential implication for improved diagnosis of wound healing and infection.

A multicentre randomised controlled trial evaluating the efficacy of dehydrated human amnion/chorion membrane (EpiFix® ) allograft for the treatment of venous leg ulcers

A randomised, controlled, multicentre clinical trial was conducted to evaluate the efficacy of dehydrated human amnion/chorion membrane (EpiFix) allograft as an adjunct to multilayer compression therapy for the treatment of non-healing full-thickness venous leg ulcers. We randomly assigned 109 subjects to receive EpiFix and multilayer compression (n = 52) or dressings and multilayer compression therapy alone (n = 57). Patients were recruited from 15 centres around the USA and were followed up for 16 weeks. The primary end point of the study was defined as time to complete ulcer healing. Participants receiving weekly application of EpiFix and compression were significantly more likely to experience complete wound healing than those receiving standard wound care and compression (60% versus 35% at 12 weeks, P = 0·0128, and 71% versus 44% at 16 weeks, P = 0·0065). A Kaplan-Meier analysis was performed to compare the time-to-healing performance with or without EpiFix, showing a significantly improved time to healing using the allograft (log-rank P = 0·0110). Cox regression analysis showed that subjects treated with EpiFix had a significantly higher probability of complete healing within 12 weeks (HR: 2·26, 95% confidence interval 1·25-4·10, P = 0·01) versus without EpiFix. These results confirm the advantage of EpiFix allograft as an adjunct to multilayer compression therapy for the treatment of non-healing, full-thickness venous leg ulcers.

Systematic review of patient-reported outcome measures in patients with varicose veins

Background

Varicose veins can affect quality of life. Patient-reported outcome measures (PROMs) provide a direct report from the patient about the impact of the disease without interpretation from clinicians or anyone else. The aim of this study was to examine the quality of the psychometric evidence for PROMs used in patients with varicose veins.

Methods

A systematic review was undertaken to identify studies that reported the psychometric properties of generic and disease-specific PROMs in patients with varicose veins. Literature searches were conducted in databases including MEDLINE, up to July 2016. The psychometric criteria used to assess these studies were adapted from published recommendations in accordance with US Food and Drug Administration guidance.

Results

Nine studies were included which reported on aspects of the development and/or validation of one generic (36-Item Short Form Health Survey, SF-36®) and three disease-specific (Aberdeen Varicose Vein Questionnaire, AVVQ; Varicose Veins Symptoms Questionnaire, VVSymQ®; Specific Quality-of-life and Outcome Response – Venous, SQOR-V) PROMs. The evidence from included studies provided data to support the construct validity, test–retest reliability and responsiveness of the AVVQ. However, its content validity, including weighting of the AVVQ questions, was biased and based on the opinion of clinicians, and the instrument had poor acceptability. VVSymQ® displayed good responsiveness and acceptability rates. SF-36® was considered to have satisfactory responsiveness and internal consistency.

Conclusion

There is a scarcity of psychometric evidence for PROMs used in patients with varicose veins. These data suggest that AVVQ and SF-36® are the most rigorously evaluated PROMs in patients with varicose veins.

A single-arm trial indirect comparison investigation: a proof-of-concept method to predict venous leg ulcer healing time for a new acellular synthetic matrix matched to standard care control

To compare data on time to healing from two separate cohorts: one treated with a new acellular synthetic matrix plus standard care (SC) and one matched from four large UK pragmatic, randomised controlled trials [venous leg ulcer (VLU) evidence network]. We introduce a new proof-of-concept strategy to a VLU clinical evidence network, propensity score matching and sensitivity analysis to predict the feasibility of the new acellular synthetic matrix plus SC for success in future randomised, controlled clinical trials. Prospective data on chronic VLUs from a safety and effectiveness study on an acellular synthetic matrix conducted in one wound centre in the UK (17 patients) and three wound centres in Australia (36 patients) were compared retrospectively to propensity score-matched data from patients with comparable leg ulcer disease aetiology, age, baseline ulcer area, ulcer duration, multi-layer compression bandaging and majority of care completed in specialist wound centres (average of 1 visit per week), with the outcome measures at comparable follow-up periods from patients enrolled in four prospective, multicentre, pragmatic, randomised studies of venous ulcers in the UK (the comparison group; VLU evidence network). Analysis using Kaplan-Meier survival curves showed a mean healing time of 73·1 days for ASM plus SC (ASM) treated ulcers in comparison with 83·5 days for comparison group ulcers treated with SC alone (Log rank test, χ2 5·779, P = 0·016) within 12 weeks. Sensitivity analysis indicates that an unobserved covariate would have to change the odds of healing for SC by a factor of 1·1 to impact the baseline results. Results from this study predict a significant effect on healing time when using a new ASM as an adjunct to SC in the treatment of non-healing venous ulcers in the UK, but results are sensitive to unobserved covariates that may be important in healing time comparison.

Fabrication of bi-layer scaffold of keratin nanofiber and gelatin-methacrylate hydrogel: Implications for skin graft

Bi-layer scaffold composed of human hair keratin/chitosan nanofiber mat and gelatin methacrylate (GelMA) hydrogel was fabricated by using electrospinning and photopolymerization techniques. To prepare the nanofiber layer, the blend solution of human hair keratin and chitosan (mixture ratio: 5/5) was electrospun using formic acid as a solvent in the presence of poly(ethylene glycol), followed by cross-linking with glutaraldehyde. The tensile strength of the human hair keratin/chitosan nanofiber mat was much higher than that of pure human hair keratin nanofiber mat. Meanwhile, the blend nanofiber mat was relatively more compatible with HaCaT cell proliferation and keratinocyte differentiation than the pure chitosan nanofiber mat. The bi-layer scaffold was prepared by photopolymerization of GelMA under the cross-linked nanofiber mat. To evaluate the feasibility as a skin graft, human fibroblast was encapsulated in the hydrogel layer and HaCaT cells were cultured on the nanofiber layer and they were co-cultured for 10days. As a result, the encapsulated fibroblasts proliferated in the hydrogel matrix and HaCaT cells formed a cell layer on the top of scaffold, mimicking dermis and epidermis of skin tissue.

Relationship between maceration and wound healing on diabetic foot ulcers in Indonesia: a prospective study

The aim of this study was to clarify the relationship between maceration and wound healing. A prospective longitudinal design was used in this study. The wound condition determined the type of dressings used and the dressing change frequency. A total of 62 participants with diabetic foot ulcers (70 wounds) were divided into two groups: non-macerated (n = 52) and macerated wounds (n = 18). Each group was evaluated weekly using the Bates-Jensen Wound Assessment Tool, with follow-ups until week 4. The Mann-Whitney U test showed that the changes in the wound area in week 1 were faster in the non-macerated group than the macerated group (P = 0·02). The Pearson correlation analysis showed a moderate correlation between maceration and wound healing from enrolment until week 4 (P = 0·002). After week 4, the Kaplan-Meier analysis showed that the non-macerated wounds healed significantly faster than the macerated wounds (log-rank test = 19·378, P = 0·000). The Cox regression analysis confirmed that maceration was a significant and independent predictor of wound healing in this study (adjusted hazard ratio, 0·324; 95% CI, 0·131-0·799; P = 0·014). The results of this study demonstrated that there is a relationship between maceration and wound healing. Changes in the wound area can help predict the healing of wounds with maceration in clinical settings.

Maltodextrin/ascorbic acid stimulates wound closure by increasing collagen turnover and TGF-β1 expression in vitro and changing the stage of inflammation from chronic to acute in vivo

It has been reported that carbohydrates confer physicochemical properties to the wound environment that improves tissue repair. We evaluated in vitro and in vivo wound healing during maltodextrin/ascorbic acid treatment. In a fibroblast monolayer scratch assay, we demonstrated that maltodextrin/ascorbic acid stimulated monolayer repair by increasing collagen turnover coordinately with TGF-β1 expression (rising TGF-β1 and MMP-1 expression, as well as gelatinase activity, while TIMP-1 was diminished), similar to in vivo trends. On the other hand, we observed that venous leg ulcers treated with maltodextrin/ascorbic acid diminished microorganism population and improved wound repair during a 12 week period. When maltodextrin/ascorbic acid treatment was compared with zinc oxide, almost four fold wound closure was evidenced. Tissue architecture and granulation were improved after the carbohydrate treatment also, since patients that received maltodextrin/ascorbic acid showed lower type I collagen fiber levels and increased extracellular alkaline phosphatase activity and blood vessels than those treated with zinc oxide. We hypothesize that maltodextrin/ascorbic acid treatment stimulated tissue repair of chronic wounds by changing the stage of inflammation and modifying collagen turnover directly through fibroblast response.

The humanistic and economic burden of chronic wounds: a protocol for a systematic review

BACKGROUND

Chronic non-healing wounds present a substantial economic burden to healthcare system; significant reductions in quality of life for those affected, and precede often serious events such as limp amputations or even premature deaths. This burden is also likely to increase with a larger proportion of elderly and increasing prevalence of life-style diseases such as obesity and diabetes. Reviews of the evidence on the burden of illness associated with chronic wounds have not been comprehensive in scope and have not provided an assessment of the distribution of the health care costs across categories of resource use.

METHODS/DESIGN

This study is a systematic review of multiple databases for studies on adult patients with chronic wounds and with the primary objective to assess the impact on health-related quality of life by category of ulcers, and associated direct and indirect costs. Eligible studies will primary be empirical studies evaluating, describing or comparing measurement of quality of life and economic impact. Two reviewers will independently screen titles and abstracts and select studies involving adults with chronic wounds. These investigators will also independently extract data using a pre-designed data extraction form. Differences in applied methodologies and uncertainties will clearly be accounted for. Conservative valuations of costs and impact on health-related quality of life will be prioritised. Variations that may depend on age distribution, the categorisation of ulcer, healthcare system etc. will be described clearly.

DISCUSSION

The proposed systematic review will yield a comprehensive assessment of the humanistic and economic burden of chronic wounds in an adult population. A better understanding of the humanistic and economic burden of chronic wounds is essential for policy and planning purposes, to monitor trends in disease burden and not at least in order to estimate the real-world cost-effectiveness of new treatments and therapies.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42016037496.

Efficacy of a collagen-based dressing in an animal model of delayed wound healing

OBJECTIVE

The aim of this study was to evaluate in vitro and in vivo the efficacy of GBT013, a collagen-based dressing, for the treatment of chronic wounds, in a db/db mouse model of diabetes.

METHOD

Macroscopic and histologic analyses of db/db mice wound healing with GBT013 or saline gauze were assessed. The mRNA expression and the proliferation of dermal fibroblast were investigated. Matrix metalloproteinases (MMP)-2 and MMP-9 activities were quantified.

RESULTS

In db/db mice, GBT013 improves wound epithelialisation when compared with saline gauze. Histological analysis of scar tissue also shows an enhancement of remodelling associated with no sign of acute inflammation. In addition, GBT013 significantly decreases interleukin (IL)-6 and IL-8, significantly increases tissue inhibitors of metalloproteinases (TIMP)-1 and TIMP-2 fibroblast mRNA expression and significantly reduces in vitro MMP-2 and MMP-9 enzymatic activities. Moreover, GBT013 allows cell growth inside the matrix and stimulates proliferation of human dermal fibroblast.

CONCLUSION

By contributing to restore MMPs/TIMPs balance, GBT013 may function in all key stages of wound healing, such as inflammation, proliferation and tissue remodelling, and ultimately may provide a favourable environment for skin repair.

DECLARATION OF INTEREST

This work was supported by Genbiotech, the R&D subsidiary of Laboratoires Genévrier, a pharmaceutical company.

Non-healing foot ulcers in diabetic patients: general and local interfering conditions and management options with advanced wound dressings

Medical knowledge about wound management has improved as recent studies have investigated the healing process and its biochemical background. Despite this, foot ulcers remain an important clinical problem, often resulting in costly, prolonged treatment. A non-healing ulcer is also a strong risk factor for major amputation. Many factors can interfere with wound healing, including the patient's general health status (i.e., nutritional condition indicated by albumin levels) or drugs such as steroids that can interfere with normal healing. Diabetic complications (i.e., renal insufficiency) may delay healing and account for higher amputation rates observed in diabetic patients under dialysis treatment. Wound environment (e.g., presence of neuropathy, ischaemia, and infection) may significantly influence healing by interfering with the physiological healing cascade and adding local release of factors that may worsen the wound. The timely and well-orchestrated release of factors regulating the healing process, observed in acute wounds, is impaired in non-healing wounds that are blocked in a chronic inflammatory phase without progressing to healing. This chronic phase is characterised by elevated protease activity (EPA) of metalloproteinases (MMPs) and serine proteases (e.g., human neutrophil elastase) that interfere with collagen synthesis, as well as growth factor release and action. EPA (mainly MMP 9, MMP-8 and elastase) and inflammatory factors present in the wound bed (such as IL-1, IL-6, and TNFa) account for the catabolic state of non-healing ulcers. The availability of wound dressings that modulate EPA has added new therapeutic options for treating non-healing ulcers. The literature confirms advantages obtained by reducing protease activity in the wound bed, with better outcomes achieved by using these dressings compared with traditional ones. New technologies also allow a physician to know the status of the wound bed environment, particularly EPA, in a clinical setting. These may be helpful in guiding a clinician's options in treating very difficult-to-heal ulcers.

Clinical features of venous insufficiency and the risk of venous thrombosis in older people

Venous thrombosis is common in older age, with an incidence of 0·5-1% per year in those aged >70 years. Stasis of blood flow is an important contributor to the development of thrombosis and may be due to venous insufficiency in the legs. The risk of thrombosis associated with clinical features of venous insufficiency, i.e., varicose veins, leg ulcers and leg oedema, obtained with a standardized interview was assessed in the Age and Thrombosis Acquired and Genetic risk factors in the Elderly (AT-AGE) study. The AT-AGE study is a case-control study in individuals aged 70 years and older (401 cases with a first-time venous thrombosis and 431 control subjects). We calculated odds ratios (ORs) and corresponding 95% confidence intervals (CI) adjusted for age, sex and study centre. Varicose veins and leg ulcer were associated with a 1·6-fold (95% CI 1·2-2·3) and 3·3-fold increased risk of thrombosis (95% CI 1·6-6·7), respectively, while the risk was increased 3·0-fold (95% CI 2·1-4·5) in the presence of leg oedema. The risk of thrombosis was highest when all three risk factors occurred simultaneously (OR: 10·5; 95% CI 1·3-86·1). In conclusion, clinical features of venous insufficiency, i.e., varicose veins, leg ulcers and leg oedema, are risk factors for venous thrombosis in older people.

Preclinical and clinical evidence for stem cell therapies as treatment for diabetic wounds

Diabetic wounds remain a global unsolved problem and the cost of diabetes-related amputations and diabetic wound treatment is approximately US$3 billion and US$9 billion per year, respectively. Diabetic foot ulcers (DFUs) occur in 15% of all patients with diabetes and precede 84% of all diabetes-related lower leg amputations. Currently, there is no satisfying treatment for these hard-to-heal-wounds. However, as we discuss here, experimental preclinical evidence for the successful use of adult stem cell therapies for diabetic wounds gives new hope for the development of effective treatments for use in the clinic.

Evaluation of dense collagen matrices as medicated wound dressing for the treatment of cutaneous chronic wounds

Cutaneous chronic wounds are characterized by an impaired wound healing which may lead to infection and amputation. When current treatments are not effective enough, the application of wound dressings is required. To date, no ideal biomaterial is available. In this study, highly dense collagen matrices have been evaluated as novel medicated wound dressings for the treatment of chronic wounds. For this purpose, the structure, mechanical properties, swelling ability and in vivo stability of matrices concentrated from 5 to 40 mg mL(-1) were tested. The matrix stiffness increased with the collagen concentration and was associated with the fibril density and thickness. Increased collagen concentration also enhanced the material resistance against accelerated digestion by collagenase. After subcutaneous implantation in rats, dense collagen matrices exhibited high stability without any degradation after 15 days. The absence of macrophages and neutrophils evidenced their biocompatibility. Subsequently, dense matrices at 40 mg mL(-1) were evaluated as drug delivery system for ampicillin release. More concentrated matrices exhibited the best swelling abilities and could absorb 20 times their dry weight in water, allowing for an efficient antibiotic loading from their dried form. They released efficient doses of antibiotics that inhibited the bacterial growth of Staphylococcus Aureus over 3 days. In parallel, they show no cytotoxicity towards human fibroblasts. These results show that dense collagen matrices are promising materials to develop medicated wound dressings for the treatment of chronic wounds.

Cost-effectiveness of three adjunct cellular/tissue-derived products used in the management of chronic venous leg ulcers

OBJECTIVES

Determine the cost-effectiveness of three topically applied cellular/tissue-derived products (CTPs) used as adjunct therapies to standard care in the management of venous leg ulcers (VLUs).

METHODS

A three-state Markov model derived from the medical literature was developed to estimate the comparative cost-effectiveness of three CTPs in relation to VLU standard care. CTPs evaluated in the study included extracellular matrix (ECM), human skin equivalent (HSE), and living skin equivalent (LSE). The three Markov states included unhealed, healed, and death. A 1-year time horizon was used to determine the number of ulcer-free weeks and the expected costs of therapies. The payer perspective was taken in the analysis and only the direct costs of care were considered. Sensitivity analyses were performed to gauge model parameter uncertainty.

RESULTS

The expected costs for standard care, ECM, HSE, and LSE VLU therapy were $6,132, $6,732, $10,638, and $11,237, while the expected outcomes were 24, 31, 29, and 27 ulcer-free weeks, respectively. ECM was economically dominant among the three CTPs. In the base case of ECM versus standard care, the incremental cost-effectiveness ratio for ECM therapy was $86 per ulcer-free week. Sensitivity analysis did not alter ECM dominance. Clinic visits and home health utilization exhibited the greatest influence on cost.

CONCLUSIONS

ECM is the most cost-effective CTP when used in the management of VLUs as an adjunct to standard care. These findings suggest that VLU standard care therapy with ECM can yield potential cost savings and produce better outcomes than do other CTPs.