Biology of Dermal Wound Repair

Instantly adhesive and ultra-elastic patches for dynamic organ and wound repair

Bioadhesive materials and patches are promising alternatives to surgical sutures and staples. However, many existing bioadhesives do not meet the functional requirements of current surgical procedures and interventions. Here, we present a translational patch material that exhibits instant adhesion to tissues (2.5-fold stronger than Tisseel, an FDA-approved fibrin glue), ultra-stretchability (stretching to >300% its original length without losing elasticity), compatibility with rapid photo-projection (<2 min fabrication time/patch), and ability to deliver therapeutics. Using our established procedures for the in silico design and optimization of anisotropic-auxetic patches, we created next-generation patches for instant attachment to tissues while conforming to a broad range of organ mechanics ex vivo and in vivo. Patches coated with extracellular vesicles derived from mesenchymal stem cells demonstrate robust wound healing capability in vivo without inducing a foreign body response and without the need for patch removal that can cause pain and bleeding. We further demonstrate a single material-based, void-filling auxetic patch designed for the treatment of lung puncture wounds.

Biology of Tenascin C and its Role in Physiology and Pathology

Tenascin-C (TNC) is a multimodular extracellular matrix (ECM) protein hexameric with several molecular forms (180-250 kDa) produced by alternative splicing at the pre-mRNA level and protein modifications. The molecular phylogeny indicates that the amino acid sequence of TNC is a well-conserved protein among vertebrates. TNC has binding partners, including fibronectin, collagen, fibrillin-2, periostin, proteoglycans, and pathogens. Various transcription factors and intracellular regulators tightly regulate TNC expression. TNC plays an essential role in cell proliferation and migration. Unlike embryonic tissues, TNC protein is distributed over a few tissues in adults. However, higher TNC expression is observed in inflammation, wound healing, cancer, and other pathological conditions. It is widely expressed in a variety of human malignancies and is recognized as a pivotal factor in cancer progression and metastasis. Moreover, TNC increases both pro-and anti-inflammatory signaling pathways. It has been identified as an essential factor in tissue injuries such as damaged skeletal muscle, heart disease, and kidney fibrosis. This multimodular hexameric glycoprotein modulates both innate and adaptive immune responses regulating the expression of numerous cytokines. Moreover, TNC is an important regulatory molecule that affects the onset and progression of neuronal disorders through many signaling pathways. We provide a comprehensive overview of the structural and expression properties of TNC and its potential functions in physiological and pathological conditions.

An Atmospheric Plasma Jet Induces Expression of Wound Healing Genes in Progressive Burn Wounds in a Comb Burn Rat Model: A Pilot Study

Burn-related injuries are devastating injuries with a high mortality rate that affect people of all ages worldwide. We assessed the effectiveness of plasma jet treatment in altering the expression of genes involved in wound healing in a prospective longitudinal observational animal study. Six male Sprague-Dawley rats weighing 350 g were used, and burn wounds were made by applying a preheated brass comb (100°C) to the back of the rats, resulting in four full-thickness burn wounds separated by three interspaces. A total of 18 burn wounds were induced on three rats. One side of the burn, on each rat received plasma treatment (plasma group), while the other side did not (control group). The interspaces were subjected to the plasma jet for 2 minutes per day until 7 days post-wounding. Plasma treatment significantly decreased the expression of proinflammatory cytokines. Furthermore, an increase in the expression of anti-inflammatory cytokines was observed in the plasma group. We showed that plasma jet treatment could improve burn wound healing by altering the expression of genes involved in the development of wound healing.

Resistance exercise promotes the resolution and recanalization of deep venous thrombosis in a mouse model via SIRT1 upregulation

BACKGROUND

Early exercise for acute deep venous thrombosis (DVT) improves the patient's symptoms and does not increase the risk of pulmonary embolism. However, information about its effect on thrombus resolution is limited. The aim of this study was to investigate the role of resistance exercise (RE) in thrombus resolution and recanalization and determine its underlying mechanisms.  METHODS: Ninety-six C57BL/6 J mice were randomly divided into four groups: Control group (C, n = 24); DVT group (D, n = 24); RE + DVT group (ED, n = 24); and inhibitor + RE + DVT group (IED, n = 24). A DVT model was induced by stenosis of the inferior vena cava (IVC). After undergoing IVC ultrasound within 24 h post-operation to confirm DVT formation, mice without thrombosis were excluded. Other mice were sacrificed and specimens were obtained 14 or 28 days after operation. Thrombus-containing IVC was weighed, and the thrombus area and recanalization rate were calculated using HE staining. Masson's trichrome staining was used to analyze the collagen content. RT-PCR and ELISA were performed to examine IL-6, TNF-α, IL-10, and VEGF expression levels. SIRT1 expression was assessed using immunohistochemistry staining and RT-PCR. VEGF-A protein expression and CD-31-positive microvascular density (MVD) in the thrombus were observed using immunohistochemistry.  RESULTS: RE did not increase the incidence of pulmonary embolism. It reduced the weight and size of the thrombus and the collagen content. Conversely, it increased the recanalization rate. It also decreased the levels of the pro-inflammatory factors IL-6 and TNF-α and increased the expression levels of the anti-inflammatory factor IL-10. RE enhanced VEGF and SIRT1 expression levels and increased the MVD in the thrombosis area. After EX527 (SIRT1 inhibitor) was applied, the positive effects of exercise were suppressed.

CONCLUSIONS

RE can inhibit inflammatory responses, reduce collagen deposition, and increase angiogenesis in DVT mice, thereby promoting thrombus resolution and recanalization. Its underlying mechanism may be associated with the upregulation of SIRT1 expression.

A Comparative Analysis of the Wound Healing-Related Heterogeneity of Adipose-Derived Stem Cells Donors

Adipose-derived Stem cells (ASCs) are on the verge of being available for large clinical trials in wound healing. However, for developing advanced therapy medicinal products (ATMPs), potency assays mimicking the mode of action are required to control the product consistency of the cells. Thus, greater effort should go into the design of product assays. Therefore, we analyzed three ASC-based ATMPs from three different donors with respect to their surface markers, tri-lineage differentiation, proliferation, colony-forming unit capacity, and effect on fibroblast proliferation and migration, endothelial proliferation, migration, and angiogenesis. Furthermore, the transcriptome of all three cell products was analyzed through RNA-sequencing. Even though all products met the criteria by the International Society for Cell and Gene Therapy and the International Federation for Adipose Therapeutics and Science, we found one product to be consistently superior to others when exploring their potency in the wound healing specific assays. Our results indicate that certain regulatory genes associated with extracellular matrix and angiogenesis could be used as markers of a superior ASC donor from which to use ASCs to treat chronic wounds. Having a panel of assays capable of predicting the potency of the product would ensure the patient receives the most potent product for a specific indication, which is paramount for successful patient treatment and acceptance from the healthcare system.

Investigation of wound healing potential of photo-active curcumin-ZnO-nanoconjugates in excisional wound model

Wound healing, being a dynamic process consisting of hemostasis, inflammation, proliferation, and remodeling, involves the complicated interplay of various growth mediators and the cells associated repair system. Current wound healing therapies usually fail to completely regain skin integrity and functionality. Traditionally, curcumin is considered a potent natural wound healing agent as it possesses antibacterial, antioxidant, and anti-inflammatory properties. It is also known that zinc oxide (ZnO) nanoparticles (NPs) have photocatalytic properties, including the generation of reactive oxygen species. ZnO nanoaprticles are also Food and Drug Administration (FDA) approved as safe substances. While ZnO oxide requires illumination with ultraviolet light to become photocatalytically active, dye-sensitized ZnO can be activated by illumination with visible light. In the present study, we explored the wound healing potential of ZnO nanoparticles sensitized with curcumin (Cu+ZnO Nps) and illuminated with visible (blue) light generated by an array of high power LEDs. We studied the antibacterial effect of our conjugates by percentage reduction in bacterial growth and biofilm formation. The wound healing potential was analyzed by percentage wound contraction, biochemical parameters, and histopathological analysis of the wounded site. Additionally, angiogenesis and wound associated cytokines was evaluated by immunohistochemistry of CD31 and gene expression analysis of IL-1β, TNF-α, and MMP-9 after 16 days of post-wound treatment, respectively. Our study suggests that the therapeutic effect of Cu+ZnO NPs with LED illumination increases its wound healing potential by producing an antibacterial and anti-inflammatory effect. Moreover, the treatment strategy of using a nano formulation in combination with LED illumination further increases its efficacy. It was concluded that the anti-inflammatory and bactericidal effects of the LED illuminated Cu+ZnO Np showed accelerated wound healing with increased wound contraction, collagen deposition, angiogenesis, and re-epithelialization.

One Size Does Not Fit All: Diversifying Immune Function in the Skin

Our body's most outward facing epithelial barrier, the skin, serves as the frontline defense against myriad environmental assailants. To combat these motley threats, the skin has evolved a sophisticated immunological arsenal. In this article, I provide an overview of the skin's complex architecture and the distinct microniches in which immune cells reside and function. I review burgeoning literature on the synchronized immune, stromal, epithelial, and neuronal cell responses in healthy and inflamed skin. Next, I delve into the distinct requirement and mechanisms of long-term immune surveillance and tissue adaptation at the cutaneous frontier. Finally, by discussing the contributions of immune cells in maintaining and restoring tissue integrity, I underscore the constellation of noncanonical functions undertaken by the skin immune system. Just as our skin's immune system benefits from embracing diverse defense strategies, so, too, must we in the immunology research community support disparate perspectives and people from all walks of life.

The Therapeutic Effects of Oral Intake of Hydrogen Rich Water on Cutaneous Wound Healing in Dogs

This study explored the effects of drinking Hydrogen-rich water (HRW) on skin wound healing in dogs. Eight circular wounds were analyzed in each dog. The experimental group was treated with HRW thrice daily, while the control group was provided with distilled water (DW). The wound tissues of dogs were examined histopathologically. The fibroblasts, inflammatory cell infiltration, the average number of new blood vessels, and the level of malondialdehyde (MDA) and superoxide dismutase (SOD) activity in the skin homogenate of the wound was measured using the corresponding kits. The expressions of Nrf-2, HO-1, NQO-1, VEGF, and PDGF were measured using the real-time fluorescence quantitative method. We observed that HRW wounds showed an increased rate of wound healing, and a faster average healing time compared with DW. Histopathology showed that in the HRW group, the average thickness of the epidermis was significantly lower than the DW group. The average number of blood vessels in the HRW group was higher than the DW group. The MDA levels were higher in the DW group than in the HRW group, but the SOD levels were higher in the HRW group than in the DW group. The results of qRT-PCR showed that the expression of each gene was significantly different between the two groups. HRW treatment promoted skin wound healing in dogs, accelerated wound epithelization, reduced inflammatory reaction, stimulated the expression of cytokines related to wound healing, and shortened wound healing time.

Endothelial progenitor cells overexpressing platelet derived growth factor-D facilitate deep vein thrombosis resolution

To assess the therapeutic efficacy of PDGF-D-overexpressing endothelial progenitor cells (EPCs) in deep vein thrombosis. Inferior vena cava thrombosis was induced in female Sprague Dawley (SD) rats. Animals were injected via the distal vena cava with EPCs overexpressing PDGF-D after transfection with a lentiviral vector containing the PDGF-D gene. The effect on thrombosis in animals who received EPCs was evaluated using MSB staining, immunohistochemistry, immunofluorescence, and venography; the steady-state mRNA and protein levels of PDGF-D and its receptor (PDGF-Rβ) were determined by RT-PCR and Western blotting, respectively; and the PDGF-D-induced mobilization of circulating EPCs was estimated by flow cytology. Compared with controls, injection of EPCs overexpressing PDGF-D was associated with increased thrombosis resolution; recanalization; PDGF-D and PDGF-Rβ expression; induction of monocyte homing; and mobilization of EPCs to the venous circulation. In a rat model, transplantation of PDGF-D-overexpressing EPCs facilitated the resolution of deep vein thrombosis.

Bioshell calcium oxide (BiSCaO) for cleansing and healing Pseudomonas aeruginosa-infected wounds in hairless rats

BACKGROUND

Scallop shell powder is called bioshell calcium oxide (BiSCaO), which is known to possess deodorizing properties and broad antimicrobial activity against various pathogenic microbes, including viruses, bacteria, spores, and fungi.

OBJECTIVE

This study aims to investigate the applications of BiSCaO suspension cleansing in clinical situations, for instance for the prevention and treatment of infections in chronic wounds in healing-impaired patients, without delaying wound healing.

METHODS

The bactericidal activities of 1000 ppm BiSCaO suspension; 500 ppm hypochlorous acid; 1000 ppm povidone iodine; and saline were compared to evaluate in vivo disinfection and healing of Pseudomonas aeruginosa-infected wounds in hairless rats.

RESULTS

Cleansing of the infected wounds with BiSCaO suspension daily for 3 days significantly enhanced wound healing and reduced the in vivo bacterial counts, in comparison to hypochlorous acid, povidone iodine, and saline. Furthermore, histological examinations showed significantly advanced granulation tissue and capillary formation in the wounds cleansed with BiSCaO suspension than in those cleansed with the other solutions.

CONCLUSIONS

This study suggested that the possibility of using BiSCaO suspension as a disinfectant for infected wounds and limiting disinfection to 3 days may be sufficient to avoid the negative effects on wound repair.

Bioactive Fatty Acids in the Resolution of Chronic Inflammation in Skin Wounds

Significance: Optimal skin wound healing is crucial for maintaining tissue homeostasis, particularly in response to an injury. The skin immune system is under regulation of mediators such as bioactive lipids and cytokines that can initiate an immune response with controlled inflammation, followed by efficient resolution. However, nutritional deficiency impacts wound healing by hindering fibroblast proliferation, collagen synthesis, and epithelialization, among other crucial functions. In this way, the correct nutritional support of bioactive lipids and of other essential nutrients plays an important role in the outcome of the wound healing process. Recent Advances and Critical Issues: Several studies have revealed the potential role of lipids as a treatment for the healing of skin wounds. Unsaturated fatty acids such as linoleic acid, α-linolenic acid, oleic acid, and most of their bioactive products have shown an effective role as a topical treatment of chronic skin wounds. Their effect, when the treatment starts at day 0, has been observed mainly in the inflammatory phase of the wound healing process. Moreover, some of them were associated with different dressings and were tested for clinical purposes, including pluronic gel, nanocapsules, collagen films and matrices, and polymeric bandages. Therefore, future research is still needed to evaluate these dressing technologies in association with different bioactive fatty acids in a wound healing context. Future Directions: This review summarizes the main results of the available clinical trials and basic research studies and provides evidence-based conclusions. Together, current data encourage the use of bioactive fatty acids for an optimal wound healing resolution.

Hancornia speciosa serum fraction latex stimulates the angiogenesis and extracellular matrix remodeling processes

The Hancornia speciosa latex reveals angiogenic, osteogenic, and anti-inflammatory properties, which present its potential for developing of wound healing drugs; however, the latex compounds responsible for angiogenesis remain unknown. One strategy to screen these active compounds is evaluation of latex fractions. This study aimed to obtain different fractions of latex and evaluate its angiogenic activity separately using the chick chorioallantoic membrane (CAM) assay. The serum (SE) fraction was responsible for angiogenesis, which was subject to biochemical characterization and computational simulations in order to understand the contribution of H. speciosa latex in wound healing process. Our results revealed weak antioxidant potential and absence of antimicrobial activity in the SE fraction. Phytochemical analysis identified chlorogenic acids (CGA) as the main compound of SE fraction. CGA bioactivity predictions identify different molecules associated with extracellular matrix (ECM) remodeling, such as metalloproteinases, which also are overexpressed in our CAM assay experiment. Docking simulations revealed the interactions between CGA and matrix metalloproteinase 2. In conclusion, SE latex fraction stimulates angiogenesis and may influence ECM remodeling. These properties may contribute to the wound healing process, and also confirm the widespread use of this plant.

Bioshell Calcium Oxide (BiSCaO) Ointment for the Disinfection and Healing of Pseudomonas aeruginosa-Infected Wounds in Hairless Rats

Bioshell calcium oxide (BiSCaO) possesses deodorizing properties and broad microbicidal activity. This study aimed to investigate the application of BiSCaO ointment for the prevention and treatment of infection in chronic wounds in healing-impaired patients, without delaying wound healing. The bactericidal activities of 0.04, 0.2, 1, and 5 wt% BiSCaO ointment, 3 wt% povidone iodine ointment, and control (ointment only) were compared to evaluate the in vivo disinfection and healing of Pseudomonas aeruginosa-infected wounds in hairless rats. Treatment of the infected wounds with 0.2 wt% BiSCaO ointment daily for 3 days significantly enhanced wound healing and reduced the in vivo bacterial counts compared with povidone iodine ointment and control (no wound cleaning). Although 5 wt% BiSCaO ointment provided the lowest bacterial counts during 3 days' treatment, it delayed wound healing. Histological examinations showed significantly advanced granulation tissue and capillary formation in wounds treated with 0.2 wt% BiSCaO ointment for 3 days compared to wounds treated with the other ointments. This study suggested that using 0.2 wt% BiSCaO ointment as a disinfectant for infected wounds and limiting disinfection to 3 days may be sufficient to avoid the negative effects of BiSCaO on wound repair.

Ultrasound-mediated therapies for the treatment of biofilms in chronic wounds: a review of present knowledge

Bacterial biofilms are an ever-growing concern for public health, featuring both inherited genetic resistance and a conferred innate tolerance to traditional antibiotic therapies. Consequently, there is a growing interest in novel methods of drug delivery, in order to increase the efficacy of antimicrobial agents. One such method is the use of acoustically activated microbubbles, which undergo volumetric oscillations and collapse upon exposure to an ultrasound field. This facilitates physical perturbation of the biofilm and provides the means to control drug delivery both temporally and spatially. In line with current literature in this area, this review offers a rounded argument for why ultrasound-responsive agents could be an integral part of advancing wound care. To achieve this, we will outline the development and clinical significance of biofilms in the context of chronic infections. We will then discuss current practices used in combating biofilms in chronic wounds and then critically evaluate the use of acoustically activated gas microbubbles as an emerging treatment modality. Moreover, we will introduce the novel concept of microbubbles carrying biologically active gases that may facilitate biofilm dispersal.

Norfloxacin-Loaded Electrospun Scaffolds: Montmorillonite Nanocomposite vs. Free Drug

Infections in nonhealing wounds remain one of the major challenges. Recently, nanomedicine approach seems a valid option to overcome the antibiotic resistance mechanisms. The aim of this study was the development of three types of polysaccharide-based scaffolds (chitosan-based (CH), chitosan/chondroitin sulfate-based (CH/CS), chitosan/hyaluronic acid-based (CH/HA)), as dermal substitutes, to be loaded with norfloxacin, intended for the treatment of infected wounds. The scaffolds have been loaded with norfloxacin as a free drug (N scaffolds) or in montmorillonite nanocomposite (H—hybrid-scaffolds). Chitosan/glycosaminoglycan (chondroitin sulfate or hyaluronic acid) scaffolds were prepared by means of electrospinning with a simple, one-step process. The scaffolds were characterized by 500 nm diameter fibers with homogeneous structures when norfloxacin was loaded as a free drug. On the contrary, the presence of nanocomposite caused a certain degree of surface roughness, with fibers having 1000 nm diameters. The presence of norfloxacin–montmorillonite nanocomposite (1%) caused higher deformability (90–120%) and lower elasticity (5–10 mN/cm²), decreasing the mechanical resistance of the systems. All the scaffolds were proven to be degraded via lysozyme (this should ensure scaffold resorption) and this sustained the drug release (from 50% to 100% in 3 days, depending on system composition), especially when the drug was loaded in the scaffolds as a nanocomposite. Moreover, the scaffolds were able to decrease the bioburden at least 100-fold, proving that drug loading in the scaffolds did not impair the antimicrobial activity of norfloxacin. Chondroitin sulfate and montmorillonite in the scaffolds are proven to possess a synergic performance, enhancing the fibroblast proliferation without impairing norfloxacin’s antimicrobial properties. The scaffold based on chondroitin sulfate, containing 1% norfloxacin in the nanocomposite, demonstrated adequate stiffness to sustain fibroblast proliferation and the capability to sustain antimicrobial properties to prevent/treat nonhealing wound infection during the healing process.

Theoretical basis for optimal surgical incision planning to reduce hypertrophic scar formation

BACKGROUND

After approximately 24 weeks of gestation, human cutaneous wounds and incisions heal by scar formation. Continued or unregulated stimulation of tissue fibroblasts is thought to lead to an activated state with ongoing collagen deposition resulting in a visible hypertrophic scar. There is evidence that mechanical forces as sensed by fibroblasts lead to downstream events such as excessive extracellular matrix deposition. Mechanical forces acting on the wound fibroblast are exerted by underlying muscles as well as intrinsic forces found in the dermal component of the surrounding skin. Under static conditions, collagen is oriented parallel to the direction of strain. In an effort to minimize resultant scar formation various and often contradictory lines of non-extension, lines of least tension, have been described for planning optimal surgical incisions.

HYPOTHESIS

We hypothesize that it is possible to avoid longitudinal stretch on incisions and thereby minimize resultant pathologic scars if defined anatomical considerations are respected. We hypothesize that placement of skin incisions parallel to lines of minimal longitudinal stretch, non-invasively measured by orientation of collagen orientation would in turn result in minimal scar formation.

EVIDENCE

Historical recommendations often derived from human post mortem studies and animal experiments have shed some light on cutaneously observed lines of non-extension. Theoretical considerations of non-extension lines have suggested possible directions of surgical incisions. Post surgical analysis of dermatological interventions have similarly added to our understanding of possible non-extension lines. Measuring anisotropy in the skin can determine collagen orientation in the skin and may therefore allow one to objectively place incisions parallel to non-extension lines. To date no randomized clinical study in humans has addressed whether such an approach would lead to less scarring. A study involving volunteers examining many body areas seems ethically challenged.

CONCLUSION

The hypothesis, although not proven, is supported by available evidence. If our hypothesis that measurable cutaneous collagen orientation guided incisions improved scar formation then surgical incision planning would deservedly require more clinical attention. Preoperative measurement or at least pre-closure assessment of anisotropy prior to surgical incision placement or closure would notably reduce the incidence of hypertrophic scars.

Platelet-rich plasma improves the therapeutic efficacy of mesenchymal stem cells by enhancing their secretion of angiogenic factors in a combined radiation and wound injury model

Delayed wound healing after radiation exposure can cause serious cutaneous damage, and its treatment is a major clinical challenge. Although mesenchymal stem cells (MSCs) have emerged as a promising therapeutic agent in regenerative medicine, they alone do not produce satisfactory effects in a combined radiation and wound injury (CRWI) model. Here, we investigated the therapeutic effect of combined umbilical cord blood-derived (UCB)-MSCs and platelet-rich plasma (PRP) treatment on wound healing in a CRWI mouse model. First, we assessed the release of cytokines from UCB-MSCs cultured with PRP and observed changes in the expression of angiogenic factors. The angiogenic paracrine factors from UCB-MSCs cultured with PRP were assessed in human umbilical vein endothelial cells (HUVECs). To assess therapeutic efficacy, UCB-MSCs and PRP were topically implanted into a CRWT mouse model. Vascular endothelial growth factor (VEGF), a pro-angiogenic growth factor, urokinase-type plasminogen activator and contributor to VEGF-induced signalling were more highly expressed in conditioned media of UCB-MSCs cultured with PRP than in that of UCB-MSCs alone. Furthermore, conditioned media of UCB-MSCs cultured with PRP increased the formation of tube-like structures in HUVECs. Co-treatment of UCB-MSCs and PRP in a CRWI mouse model increased the wound closure rate and angiogenesis compared with an untreated irradiated group. Moreover, increased expression of VEGF and CD31 were observed in the wound tissue of co-treated mice compared with untreated irradiated mice. PRP stimulates the release of angiogenic factors from UCB-MSCs, and combined therapy of UCB-MSCs and PRP improves regeneration efficacy by enhancing angiogenesis in a CRWI model.

The Use of Copper as an Antimicrobial Agent in Health Care, Including Obstetrics and Gynecology

Health care-associated infections (HAIs) are a global problem associated with significant morbidity and mortality. Controlling the spread of antimicrobial-resistant bacteria is a major public health challenge, and antimicrobial resistance has become one of the most important global problems in current times. The antimicrobial effect of copper has been known for centuries, and ongoing research is being conducted on the use of copper-coated hard and soft surfaces for reduction of microbial contamination and, subsequently, reduction of HAIs. This review provides an overview of the historical and current evidence of the antimicrobial and wound-healing properties of copper and explores its possible utility in obstetrics and gynecology.

[Modern wound treatment-from best practice to innovation]

According to the Research Group for Primary Medical Care (PMV), approximately 890,000 people in Germany were suffering from a chronic wound in 2012. This corresponds to a prevalence of 1.1%. Ulcus cruris, diabetic ulcers and decubital ulcers are among the most frequent causes of chronic wounds (57-80%). The guarantee for successful wound care is based on a good understanding of the physiology of the wound healing process. A disorder of the phase-like course can lead to complications, delays or suspension of wound healing. There are many reasons for pathological wound healing including infections, oxygen deficiency and non-phase-adapted wound care. In addition to established wound products, innovative products such as dermal matrixes, cold plasma therapy and platelet-rich plasma represent promising therapeutic alternatives for non-healing chronic wounds.

Development of decellularized amniotic membrane as a bioscaffold for bone marrow-derived mesenchymal stem cells: ultrastructural study

Developing effective stem cell-based therapies requires the design of complex in vitro culture systems for accurate representation of the physiological stem cell niche. Human amniotic membrane (hAM) has been successfully used in clinical grafting applications due to its unique biological and regenerative properties. Decellularized hAM (d-hAM) has been previously applied to the culture of human bone marrow mesenchymal stem cells (hMSCs), promoting their expansion and differentiation into adipogenic and osteogenic lineages. In the present study, hAM was decellularized by NaOH-treatment, to provide the three-dimensional (3D) bioscaffold for culturing hMSCs. The ultrastructural differences between intact hAM and decellularized hAM were characterized using the transmission electron microscope (TEM), as well as the 3D interaction between d-hAM and hMSCs cultured on the membrane. TEM examination of the intact hAM showed many microvilli on the epithelial layer cells, active Golgi apparatus, smooth endolplasmic reticulum and the characteristic pinocytic vesicles. The epithelial layer with its structures was absent in the d-hAM. However, no observable difference was detected in the ultrastructural characteristics of the compact stromal layer of d-hAM compared to intact hAM. Both contained bundles of extra cellular matrix (ECM) proteins, and scattered elastic fibres. Cultured human mesenchymal stem cells (hMSCs) examined by TEM appeared oval to spherical in shape and had a rough and non-uniform surface with distinct protrusions or irregular fillopodia. Their diameter ranged from 20.49 to 21.6 µm. Most of the cellular organelles were also noticed. SEM examination of the prepared samples revealed unique 3D interaction between the hMSC and d-hAM, where the latter seems to envelop the segments of the hMSCs lying on the surrounding membrane. This study shows that the decellularization process affected the epithelial layer only of hAM and had no effect on altering the presence of ECM components present in the stromal layer of the d-hAM. The interaction between hMSCs and d-hAM maybe mediated by hAM components other than human amniotic epithelial cells, such as ECM components or MSCs present in the deeper spongy layer of the membrane or/and the adhesive components of the basement membrane of the removed epithelial layer.

The effect of Korean Red Ginseng on full-thickness skin wound healing in rats

Background

Panax ginseng is regarded as one of the best compounds for promoting health, and it has been used traditionally as a medicinal herb. Recently, Korean Red Ginseng (RG) has been shown to protect skin from aging and wrinkling; it can also relieve atopic dermatitis and allergy symptoms. This study aimed to evaluate RG's effects on the regeneration of the full-thickness skin wounds in rat.

Methods

Full-thickness skin wounds were generated in rats, and then RG was administered either orally or topically. The wound-healing effects of RG were investigated by assessing wound size, mRNA expression patterns of genes related to wound healing, histological staining, and measurements of lipid, moisture, and elasticity in skin tissues.

Results

The wound size was smaller, and tissue regeneration rate was faster in the RG-treated group than that in the control group on days 15 and 20 after initiating treatment. On postoperative day 20, skin lipid and moisture content had increased significantly in the RG-treated group. Significant increases in the gene expression levels of transforming growth factor-β1 and vascular endothelial growth factor were found in the RG group during the early stages of wound healing. Matrix metalloproteinase-1 and matrix metalloproteinase-9 showed significant increases in gene expression levels on day 20.

Conclusion

The results suggested that RG may promote healing of full-thickness skin wounds in rats. They also provided basic insights into the effects of RG on skin regeneration, supporting its use as a dressing material for wound treatment and its development as a functional food.

Radiotherapy-Induced Skin Reactions Induce Fibrosis Mediated by TGF-β1 Cytokine

Purpose:

This study aimed to investigate radiation-induced lesions on the skin in an experimental animal model. Methods and Materials: Cutaneous wounds were induced in Wistar rats by 4 MeV energy electron beam irradiation, using a dose rate of 240 cGy/min, for 3 different doses (10 Gy, 40 Gy, and 60 Gy). The skin was observed 5, 10, and 25 days (D) after ionizing radiation exposition.

Results:

Infiltrate inflammatory process was observed in D5 and D10, for the 40 Gy and 60 Gy groups, and a progressive increase of transforming growth factor β1 is associated with this process. It could also be noted a mischaracterization of collagen fibers at the high-dose groups.

Conclusion:

It was observed that the lesions caused by ionizing radiation in rats were very similar to radiodermatitis in patients under radiotherapy treatment.

Advances in Knowledge:

This study is important to develop strategies to prevent radiation-induced skin reactions.

Evaluation of subcutaneous infiltration of autologous platelet-rich plasma on skin-wound healing in dogs

Platelet-rich plasma (PRP) is known to be rich in growth factors and cytokines, which are crucial to the healing process. This study investigate the effect of subcutaneous (S/C) infiltration of autologous PRP at the wound boundaries on wound epithelization and contraction. Five adult male mongrel dogs were used. Bilateral acute full thickness skin wounds (3 cm diameter) were created on the thorax symmetrically. Right side wounds were subcutaneously infiltrated with activated PRP at day 0 and then every week for three consecutive weeks. The left wound was left as control. Wound contraction and epithelization were clinically evaluated. Expression of collagen type I (COLI) A2, (COLIA2),histopathology and immunohistochemical (IHC) staining of COLI α1 (COLIA1) were performed on skin biopsies at first, second and third weeks. The catalase activity, malondialdehyde (MDA) concentration and matrix metalloproteinase (MMP) 9 (MMP-9) activity were assessed in wound fluid samples. All data were analysed statistically. The epithelization percent significantly increased in the PRP-treated wound at week 3. Collagen was well organized in the PRP-treated wounds compared with control wounds at week 3. The COLIA2 expression and intensity of COLIA1 significantly increased in PRP-treated wounds. MDA concentration was significantly decreased in PRP-treated wound at week 3. The catalase activity exhibited no difference between PRP treated and untreated wounds. The activity of MMP-9 reached its peak at the second week and was significantly high in the PRP-treated group. S/C infiltration of autologous PRP at the wound margins enhances the wound epithelization and reduces the scar tissue formation.

Efficacy of bubaline fibrin glue on full-thickness pinch and punch skin grafting in a pig

Fibrin glue, which is formed from the action of thrombin (a serine protease) on fibrinogen, has been developed for use as an adhesive to increase the success of skin graft surgery. The objective of this study was to evaluate if bubaline fibrin glue would promote skin graft survival in pigs. The grafting was divided into two steps. First, granulation wound preparation was performed in a healthy swine by creating four full-skin depth wounds (3 × 12 cm²) at the dorsal part of the loin area on each side. Second, pinch and punch skin grafting, where eight skin discs (0.6 cm diameter) were regularly placed (0.6 cm distance apart) in the granulation tissue bed of each wound, was performed 5 days later. The bubaline fibrin glue was added prior to application of the 16 skin graft discs in two of the wounds, while no glue was added to the other 16 skin graft discs in the other two wounds. The number of surviving graft pieces and histological examination was evaluated after 3, 7, and 14 days post-operation and compared by pairing between the control and the bubaline fibrin glue groups. The number of grafts that remained at 3 and 7 days post-operation and the number of new microvessels at 3 days post-operation were significantly higher ( p < 0.05) in the bubaline fibrin glue group than in the control group. However, there was no significant difference in the number of fibroblasts, the intensity of scarring and the intensity of inflammation between the two groups, except for the significantly lower intensity of inflammation at 7 days post-operation in the bubaline fibrin glue group. In conclusion, bubaline fibrin glue has the advantage of decreasing the skin graft loss by approximately 31.3-37.5% compared with the control group and also promotes angiogenesis.

Enhancement of Wound Healing by Non-Thermal N2/Ar Micro-Plasma Exposure in Mice with Fractional-CO2-Laser-Induced Wounds

Micro-plasma is a possible alternative treatment for wound management. The effect of micro-plasma on wound healing depends on its composition and temperature. The authors previously developed a capillary-tube-based micro-plasma system that can generate micro-plasma with a high nitric oxide-containing species composition and mild working temperature. Here, the efficacy of micro-plasma treatment on wound healing in a laser-induced skin wound mouse model was investigated. A partial thickness wound was created in the back skin of each mouse and then treated with micro-plasma. Non-invasive methods, namely wound closure kinetics, optical coherence tomography (OCT), and laser Doppler scanning, were used to measure the healing efficiency in the wound area. Neo-tissue growth and the expressions of matrix metallopeptidase-3 (MMP-3) and laminin in the wound area were assessed using histological and immunohistochemistry (IHC) analysis. The results show that micro-plasma treatment promoted wound healing. Micro-plasma treatment significantly reduced the wound bed region. The OCT images and histological analysis indicates more pronounced tissue regrowth in the wound bed region after micro-plasma treatment. The laser Doppler images shows that micro-plasma treatment promoted blood flow in the wound bed region. The IHC results show that the level of laminin increased in the wound bed region after micro-plasma treatment, whereas the level of MMP-3 decreased. Based on these results, micro-plasma has potential to be used to promote the healing of skin wounds clinically.

Tumour endothelial marker-8 in wound healing and its impact on the proliferation and migration of keratinocytes

Chronic wound management represents a significant burden on healthcare systems and negatively impacts on the quality of patient life. New strategies to understand and identify wounds that will not heal in a normal manner are required. Tumour endothelial marker‑8 (TEM‑8) has been implicated in the wound healing and angiogenesis processes. TEM‑8 expression was examined at the transcript level in a cohort of acute (n=10) and chronic (n=14) wounds and in normal skin (n=10). Protein analysis of TEM‑8 was also undertaken for this cohort using immunohistochemistry (IHC). TEM‑8 impact on keratinocyte cell growth and migration was assessed following TEM‑8 ribozyme transgene transfection of human HaCaT keratinocytes using cell growth and electric cell‑substrate impedance sensing (ECIS)‑based assays. Expression of TEM‑8 was observed to be increased in acute wounds compared to chronic wounds and normal skin using quantitative polymerase chain reaction transcript analysis and IHC staining of wound tissues. Knockdown of TEM‑8 in HaCaT cells, using two independent ribozyme transgenes, resulted in significant decreases in cell growth as well as reductions in the rate of migration assessed using an ECIS‑based system. TEM‑8 may be differentially expressed between wound types and loss of this molecule impacts HaCaT growth and migration, potentially implicating this molecule as a factor involved in successful progression of wound healing.

The Use of Biologic Scaffolds in the Treatment of Chronic Nonhealing Wounds

Significance: Injuries to the skin as a result of illness or injury, particularly chronic nonhealing wounds, present a major healthcare problem. Traditional wound care approaches attempt to control the underlying causes, such as infection and ischemia, while the application of wound dressings aims to modify a poorly healing wound environment into a microenvironment more closely resembling an acute wound allowing the body to heal the wound naturally. Recent Advances: Regenerative medicine approaches, such as the use of biologic scaffold materials comprising an intact extracellular matrix (ECM) or individual components of the ECM, are providing new therapeutic options that focus upon the provision of biochemical cues that alter the wound microenvironment to facilitate rapid restoration of normal skin architecture. Critical Issues: The incidence of chronic nonhealing wounds continues to increase. For example, between 15% and 20% of diabetics are likely to develop chronic, nonhealing foot wounds creating an increasing burden on healthcare systems worldwide. Future Directions: Developing a thorough understanding of wound microenvironment and the mechanisms by which biologic scaffolds work in vivo has the potential to markedly improve outcomes in the clinical translation for the treatment of chronic wounds.

Immunohistochemical Expression of Collagens in the Skin of Horses Treated with Leukocyte-Poor Platelet-Rich Plasma

This study evaluated the immunohistochemical expression of type I (COL I) and III (COL III) collagens during the healing process of skin treated with leukocyte-poor platelet-rich plasma (LP-PRP). Seven healthy gelding crossbred horses aged 16 to 17 years were used. Two rectangle-shaped wounds were created surgically in the right and left gluteal regions. Twelve hours after wound induction, 0.5 mL of the LP-PRP was administered in each edge of the wounds of one of the gluteal regions. The contralateral region was used as control (CG). Three samples were obtained: after wound induction (T0), 14 days (T1) of healing process, and after complete closure of the skin (T2). The normal skin (T0) showed strong staining for type III and I collagen in papillary and reticular dermis, respectively. In the scar of the treated group, COL III showed important (p < 0.05) increase in immunoreaction in T2 compared with T1. The administration of a single dose of LP-PRP 12 h after induction of wound in horses does not influence formation of collagens I and III. However, the intense labeling for COL III suggests that the tissue was still weak during the macroscopic closure of the wound, demonstrating that healing was not completely finished.

Stem Cells for Cutaneous Wound Healing

Optimum healing of a cutaneous wound involves a well-orchestrated cascade of biological and molecular processes involving cell migration, proliferation, extracellular matrix deposition, and remodelling. When the normal biological process fails for any reason, this healing process can stall resulting in chronic wounds. Wounds are a growing clinical burden on healthcare systems and with an aging population as well as increasing incidences of obesity and diabetes, this problem is set to increase. Cell therapies may be the solution. A range of cell based approaches have begun to cross the rift from bench to bedside and the supporting data suggests that the appropriate administration of stem cells can accelerate wound healing. This review examines the main cell types explored for cutaneous wound healing with a focus on clinical use. The literature overwhelmingly suggests that cell therapies can help to heal cutaneous wounds when used appropriately but we are at risk of clinical use outpacing the evidence. There is a need, now more than ever, for standardised methods of cell characterisation and delivery, as well as randomised clinical trials.

A new 9,10-dihydrophenanthrene and cell proliferative 3,4-δ-dehydrotocopherols from Stemona tuberosa

A new compound, 9,10-dihydro-5-methoxy-8-methyl-2,7-phenanthrenediol (1), was isolated from the roots of Stemona tuberosa Lour. (Stemonaceae) together with two new optically active compounds, (2S,4'R,8'R)-3,4-δ-dehydrotocopherol (2) and (2R,4'R,8'R)-3,4-δ-dehydrotocopherol (3). The structures of compounds 1-3 were determined on the basis of spectroscopic data analysis. Compounds 2 and 3 were each purified from a stereoisomeric mixture of 2 and 3 by preparative HPLC using a chiral column for the first time. The absolute configurations at C-2 of 2 and 3 were determined by Circular Dichroism (CD) experiments. As a part of the research to find natural wound healing agents, all isolates and the mixture of 2 and 3 were evaluated for their cell proliferative effects using a mouse fibroblast NIH3T3 and a HeLa human cervical cancer cell line. As a result, 1, 2, 3, or the mixture of 2 and 3 showed 41.6%, 78.4%, 118.6%, 38.2% increases of cell proliferation in the mouse fibroblast NIH3T3 respectively, compared to 28.4% increase of δ-tocopherol. Moreover, none of them induced cancer cell proliferation. Therefore, 3,4-δ-dehydrotocopherols, especially pure isomers 2 and 3 can be suggested as potential wound healing agents.

Colonization of Klebsiella pneumoniae inside fistula tracts: a possible risk factor for failure of fibrin glue-assisted closure

GOALS

This study was designed to investigate the risk factors affecting glue-assisted closure (GAC) in the enterocutaneous fistula (ECF) patients receiving glue application.

BACKGROUND

ECF is a challenging problem in surgical practice, and it is difficult to resolve by spontaneous closure. Currently, GAC is popular when treating fistulas, but data related to risk factors are limited.

METHODS

We retrospectively analyzed 82 patients with 93 ECFs, who had autologous glue sealing from 2010 to 2012 in a referral center. Their demographic data, clinical records, and fistula characteristics were collected. Both univariate analysis and multivariate Cox proportional hazards model were used to determine the prognostic factors affecting closure.

RESULTS

During the 14-day treatment period, 78.5% (73/93) of the fistulas achieved GAC. We excluded 3 reopened fistulas and investigated 90 ECFs from 79 patients. Univariate analysis demonstrated that patients with high levels of CRP, high CRP:prealbumin ratio, elevated blood glucose, and specific pathogen colonization, together with lower GI location, greater output volume, and shorter tract length, had a poor outcome (P<0.05). Using multivariate analysis, monomicrobial and polymicrobial colonization with Klebsiella pneumoniae inside the fistula tracts (hazard ratio, 0.191; 95% confidence interval, 0.045-0.810; P=0.025) was a statistically significant risk factor for failure of fistula closure.

CONCLUSIONS

The presence of monomicrobial and polymicrobial colonization with K. pneumoniae in fistulous tracts was an independent risk factor for failure of GAC in patients receiving glue application. Better debridement of the tracts should be performed before the glue sealing.

The role of nuclear hormone receptors in cutaneous wound repair

The cutaneous wound repair process involves balancing a dynamic series of events ranging from inflammation, oxidative stress, cell migration, proliferation, survival and differentiation. A complex series of secreted trophic factors, cytokines, surface and intracellular proteins are expressed in a temporospatial manner to restore skin integrity after wounding. Impaired initiation, maintenance or termination of the tissue repair processes can lead to perturbed healing, necrosis, fibrosis or even cancer. Nuclear hormone receptors (NHRs) in the cutaneous environment regulate tissue repair processes such as fibroplasia and angiogenesis. Defects in functional NHRs and their ligands are associated with the clinical phenotypes of chronic non-healing wounds and skin endocrine disorders. The functional relationship between NHRs and skin niche cells such as epidermal keratinocytes and dermal fibroblasts is pivotal for successful wound closure and permanent repair. The aim of this review is to delineate the cutaneous effects and cross-talk of various nuclear receptors upon injury towards functional tissue restoration.

Evaluation of lipoic acid topical application on rats skin wound healing

PURPOSE

To evaluate the effects of lipoic acid (thioctic acid) topical application on wound healing on rats skin, and the consequences of lipoic acid nanoencapsulation on this process.

METHODS

The model used was the healing activity on wounds induced by surgical incision on rats skin (n = 44). The parameters analyzed (11 days) were wound healing rate and histology (vascular proliferation, polymorphonuclear or mononuclear cells, and collagen synthesis or reepithelialization), after application of free lipoic acid or lipoic acid- loaded nanocapsules. The antioxidant activity of these formulations was evaluated by lipid peroxidation test.

RESULTS

It was demonstrated for the first time that the topical application of lipoic acid improves wound healing. On the seventh day after surgery, the animals treated with lipoic acid showed increased healing rate (60.7 ± 8.4%) compared to the negative control group (43.0 ± 17.4%), as so improvement of histological parameters. The nanoencapsulation reverted the pro-oxidant activity presented in vitro by lipoic acid, whereas diminished wound repair.

CONCLUSIONS

The topical application of lipoic acid produced an increase in the skin wound healing, which may be related to its pro-oxidant activity. On the other hand, the nanoencapsulation of the lipoic acid reversed the pro-oxidant activity, although presented minor healing activity.

Efficacy and Tolerability of a New Pharmaceutical Form of Betamethasone Valerate in the Prevention of Hypertrophic Scars following Anterior Trunk Plastic Surgery: A Preliminary Exploratory Study

Hypertrophic scars are fibroproliferative diseases of the skin. Many treatment options are now available, but none is completely effective. The primary objective of this study was to compare the efficacy of a betamethasone valerate (BMV) 2.25 mg plaster versus no treatment in the prevention of hypertrophic scars after anterior trunk plastic surgery. An exploratory, open, prospective, controlled study was carried out on 16 consecutive patients with postoperative wounds. A 12-week daily treatment was initiated after wounds cicatrisation. The effect of a daily application of the plaster was compared to no treatment by dividing the wound into 2–4 parts. The wound evaluation was performed during the treatment period at 2, 4, 8 and 12 weeks, and 6 months after the end of the treatment. A total of 60 wounds was evaluated. Pain and itching improved in both groups after 12 weeks. However, only the wounds treated with BMV plaster showed a significantly greater and more rapid improvement as compared with the non-treated wounds after 4 and 8 weeks of treatment in all the evaluated parameters (p<0.0001). The efficacy and tolerability of BMV plaster in the prevention of hypertrophic scar development is promising.

The stimulatory effects of alpha1-adrenergic receptors on TGF-beta1, IGF-1 and hyaluronan production in human skin fibroblasts

Skin fibroblasts modulate tissue repair, wound healing and immunological responses. Adrenergic receptors (ARs) mediate important physiological functions, such as endocrine, metabolic and neuronal activity. In this study, the expression α1A-ARs in human skin fibroblasts is examined and verified. Regulatory effects of α1-agonist cirazoline on cell migration and the production of transforming growth factor β1 (TGF-β1), insulin-like growth factor 1 (IGF-1), hyaluronan (HA), fibronectin and procollagen type I carboxy-terminal peptide (PIP) by human skin fibroblasts are assessed and validated. α1A-AR mRNA and protein were found in human skin fibroblasts WS1. Exposure of cirazoline doubled skin fibroblast migration and the increase in cell migration was attenuated by α1-antagonist prazosin. TGF-β1 mRNA and production were enhanced after exposure to cirazoline and IGF-1 production was also increased after treatment with cirazoline. Exposure to cirazoline also enhanced HA and PIP production. The increases in TGF-β1, IGF-1, HA and PIP production were partially abolished in fibroblasts transfected with α1A-AR short interfering RNAs, indicating that α1A-ARs are involved in the cirazoline-induced increases in TGF-β1, IGF-1, HA and PIP production. Thus, α1A-ARs are stably expressed and stimulate cell migration and TGF-β1, IGF-1, HA and PIP production in human skin fibroblasts. Moreover, TGF-β1, IGF-1, HA and PIP production and the cell migration of human skin fibroblasts are possibly modulated by natural catecholamines produced by the endocrine system or sympathetic innervation, which could directly or indirectly participate in cytokine secretion, fibroblast migration and matrix production of wound healing in the skin.

Reversibility of abdominal wall atrophy and fibrosis after primary or mesh herniorrhaphy

OBJECTIVE

To determine whether primary or mesh herniorrhaphy reverses abdominal wall atrophy and fibrosis associated with hernia formation.

BACKGROUND

We previously demonstrated that hernia formation is associated with abdominal wall atrophy and fibrosis after 5 weeks in an animal model.

METHODS

A rat model of chronic incisional hernia was used. Groups consisted of uninjured control (UC, n = 8), sham repair (SR, n = 8), unrepaired hernia (UR, n = 8), and 2 repair groups: primary repair (PR, n = 8) or tension-free polypropylene mesh repair (MR, n = 8) hernia repair on postoperative day (POD) 35. All rats were killed on POD 70. Intact abdominal wall strips were cut perpendicular to the wound for tensiometric analysis. Internal oblique muscles were harvested for fiber type and size determination.

RESULTS

No hernia recurrences occurred after PR or MR. Unrepaired abdominal walls significantly demonstrated greater stiffness, increased breaking and tensile strengths, yield load and yield energy, a shift to increased type IIa muscle fibers than SR (15.9% vs 9.13%; P < 0.001), and smaller fiber cross-sectional area (CSA, 1792 vs 2669 μm(2); P < 0.001). PR failed to reverse any mechanical changes but partially restored type IIa fiber (12.9% vs 9.13% SR; P < 0.001 vs 15.9% UR; P < 0.01) and CSA (2354 vs 2669 μm(2) SR; P < 0.001 vs 1792 μm(2) UR; P < 0.001). Mesh-repaired abdominal walls demonstrated a trend toward an intermediate mechanical phenotype but fully restored type IIa muscle fiber (9.19% vs 9.13% SR; P > 0.05 vs 15.9% UR; P < 0.001) and nearly restored CSA (2530 vs 2669 μm(2) SR; P < 0.05 vs 1792 μm(2) UR; P < 0.001).

CONCLUSIONS

Mesh herniorrhaphy more completely reverses atrophic abdominal wall changes than primary herniorrhaphy, despite failing to restore normal anatomic muscle position. Techniques for hernia repair and mesh design should take into account abdominal wall muscle length and tension relationships and total abdominal wall compliance.

Chronic venous leg ulcers are associated with high levels of metalloproteinases-9 and neutrophil gelatinase-associated lipocalin

Venous ulcers are related to dysfunctions in extracellular matrix. Both matrix metalloproteinases (MMP) and neutrophil gelatinase-associated lipocalin (NGAL) could play a role in the healing process in patients with chronic venous ulcers. We evaluated the role of MMP-9 and NGAL in the healing process in venous ulceration. We performed an open-label, parallel groups, single clinical center study. Patients with chronic venous leg ulcers represented the test group (Group I), whereas patients without chronic ulcers represented the control group (Group II). In Group I plasma and wound fluid samples were collected at the time of admission, at the time of the surgery, and at the follow-up, while ulcer tissues were taken at the time of the surgery. In Group II, plasma and wound fluid were collected at admission and at the time of the surgery, whereas skin tissues were collected at the time of the surgery. Enzyme-linked immunosorbent assay test was used to evaluate the levels of MMP-9 and NGAL in plasma and wound fluid, whereas Western blot analysis was performed to estimate the expression of MMP-9 and NGAL in tissues. Enzyme-linked immunosorbent assay tests revealed significantly higher levels of MMP-9 and NGAL in both plasma and wound fluid of patients with ulcers compared to patients without ulcers (p < 0.01). Moreover, Western blot analysis documented an increased expression of MMP-9 and NGAL in biopsy tissue of patients with ulcers compared to patients without ulcers (p < 0.01). In conclusion MMP-9 and NGAL may correlate with the clinical course of venous ulcers.

Low molecular weight heparin improves healing of chronic venous ulcers especially in the elderly

Venous ulcers are common, especially in the elderly, accounting for more than 50% of all lower extremity ulcers with important socioeconomic problems. Improving extracellular matrix functioning, by heparin administration, seems to be a way to support wound healing. A total of 284 patients with venous ulcers were recruited in a 4-year period. All patients were subjected to the most appropriate treatment after considering their preference (compression therapy followed or not by vein surgery). Patients were randomised into two groups of 142 persons in each (group A and group B as cases and controls, respectively). Patients of group A, in addition to the basic treatment as described earlier, received administration of nadroparin 2850 IU/0.3 ml through subcutaneous injection once a day for 12 months, whereas group B patients received basic treatment alone. Healing was assessed by means of direct ulcer tracing with computerised planimetry. Group A showed a healing rate of 83·80% at 12 months, whereas that of group B was 60·56%. Results by age group surprisingly showed that the group of older patients took the most advantage from long-term treatment with low molecular weight heparin; this group also had lowest recurrence rate.

Response of fibroblasts to transforming growth factor-β1 on two-dimensional and in three-dimensional hyaluronan hydrogels

Transforming growth factor-β1 (TGF-β1), an important cytokine with multiple functions, is secreted during wound healing. Previous studies have utilized two-dimensional (2D) cell culture to elucidate the functions of TGF-β1; however, 2D culture does not represent the complex three-dimensional (3D) in vivo environment. Using a synthetic hyaluronan (HA) extracellular matrix (ECM) hydrogel, we investigated the effect of TGF-β1 on fibroblasts cultured in three conditions--on tissue culture polystyrene (TCP), on HA (2D), and in HA (3D). After TGF-β1 treatment (0.1 to 20 ng/mL), morphological features and ECM regulation were analyzed by immunocytochemistry, Western blot, quantitative polymerase chain reaction, and zymogram assays. On TCP, cells showed the typical spindle shape with strong alpha smooth muscle actin (α-SMA) staining of cytoplasmic myofilaments along the cell axes after TGF-β1 treatment; on HA (2D), spindle-shape cells showed little α-SMA staining; in HA (3D), cells were smaller and rounded with less α-SMA deposition. The α-SMA gene and protein expression on TCP were significantly upregulated by TGF-β1, but TGF-β1 did not induce α-SMA expression in the presence of HA (both 2D and 3D). 3D HA culture significantly downregulated collagen I, III, and fibronectin expression, increased matrix metalloproteinase 1 and 2 (MMP1/MMP2) activity, upregulated MMP1 mRNA and downregulated TIMP3 mRNA expression. This study suggested that exogenous HA, particularly in 3D culture, appears to suppress ECM production, enhances ECM degradation and remodeling, and inhibits myofibroblast differentiation without decreasing TGF-β receptor expression.