Full-thickness Excisional Skin Wounds Research Articles

Pyroxylin-based liquid bandage forms a mechanically active protective film to facilitate skin wound healing in mice

Wound healing requires interplay between cells and molecules. Recent evidence has demonstrated that liquid bandages promote wound healing by forming a protective barrier against contamination, attenuating inflammation, and enhancing re-epithelialization and angiogenesis. In this study, we evaluated the wound healing activity of pyroxylin-based liquid bandage (LiQuiPlast®) in eight-week-old C57BL/6 male mice by generating a single 4 mm diameter full-thickness excisional skin wound on the dorsum. In the LiQuiPlast® group, the liquid bandage was applied on day 0 and was replaced every four days. Wound size was monitored every day for two weeks. The results showed that LiQuiPlast® was mechanically active (induced wound contraction), which promoted a significant wound size reduction (27 %−39 %, compared to the control group) on days 1–4 postinjury. In addition, a significant reduction in wound size was observed again in the LiQuiPlast® group (25 %−29 %, compared to the controls) on days 8−9 postinjury. LiQuiPlast®-treated wounds showed no scab. Immunohistochemistry analyses displayed a reduction in neutrophils and tumor necrosis factor-α levels in LiQuiPlast®-treated wounds, compared to the control group on day 4 postinjury (the inflammatory phase). In addition, LiQuiPlast®-treated mice had enhanced keratinocyte proliferation than control mice during this time. On day 13 postinjury, LiQuiPlast® significantly reduced hypertrophic scarring and enhanced expression and reorganization of collagen fiber compared to control mice. In conclusion, we show that LiQuiPlast® acts as a mechanically active protective film, which promotes moist wound healing by promoting wound contraction, no scab formation, attenuated inflammation, enhanced keratinocyte proliferation, and decreased scarring.

Accelerated full-thickness skin wound tissue regeneration by self-crosslinked chitosan hydrogel films reinforced by oxidized CNC-AgNPs stabilized Pickering emulsion for quercetin delivery

BackgroundThe non-toxic self-crosslinked hydrogel films designed from biocompatible materials allow for controlled drug release and have gathered remarkable attention from healthcare professionals as wound dressing materials. Thus, in the current study the chitosan (CS) film is infused with oil-in-water Pickering emulsion (PE) loaded with bioactive compound quercetin (Qu) and stabilized by dialdehyde cellulose nanocrystal-silver nanoparticles (DCNC-AgNPs). The DCNC-AgNPs play a dual role in stabilizing PE and are involved in the self-crosslinking with CS films. Also, this film could combine the advantage of the controlled release and synergistic wound-healing effect of Qu and AgNPs.ResultsThe DCNC-AgNPs were synthesized using sodium periodate oxidation of CNC. The DCNC-AgNPs were used to stabilize oil-in-water PE loaded with Qu in its oil phase by high speed homogenization. Stable PEs were prepared by 20% v/v oil: water ratio with maximum encapsulation of Qu in the oil phase. The Qu-loaded PE was then added to CS solution (50% v/v) to prepare self-crosslinked films (CS-PE-Qu). After grafting CS films with PE, the surface and cross-sectional SEM images show an inter-penetrated network within the matrix between DCNC and CS due to the formation of a Schiff base bond between the reactive aldehyde groups of DCNC-AgNPs and amino groups of CS. Further, the addition of glycerol influenced the extensibility, swelling ratio, and drug release of the films. The fabricated CS-PE-Qu films were analyzed for their wound healing and tissue regeneration potential using cell scratch assay and full-thickness excisional skin wound model in mice. The as-fabricated CS-PE-Qu films showed great biocompatibility, increased HaCat cell migration, and promoted collagen synthesis in HDFa cells. In addition, the CS-PE-Qu films exhibited non-hemolysis and improved wound closure rate in mice compared to CS, CS-Qu, and CS-blank PE. The H&E staining of the wounded skin tissue indicated the wounded tissue regeneration in CS-PE-Qu films treated mice.ConclusionResults obtained here confirm the wound healing benefits of CS-PE-Qu films and project them as promising biocompatible material and well suited for full-thickness wound healing in clinical applications.Graphical

Effects of common centaury (Centaurium erythraea) oil and laurel (Laurus nobilis) seed oil on full-thickness excisional skin wound healing in rats

The aim was to investigate the effects of common centaury (Centaurium erythraea) oil and laurel (Laurus nobilis) seed oil in a full-thickness excisional skin wound model in rats. In the study, 18 adult male Wistar rats were divided into three groups (n=6) as control (CO) group, common centaury oil (CCO) group, and laurel seed oil (LSO) group. Under general anesthesia, a full-thickness excisional wound (2.25 cm²) was created on the caudal of the interscapular region on the back of the rats. Treatments were applied topically once a day in all groups. Wound area measurements revealed that the use of CCO accelerated wound healing, while the use of LSO has disturbed. In the histopathological results, blood vessel formation, fiber synthesis, granulation and mononuclear cells in the wounds were higher in the CCO group than the other groups, and higher in the LSO group than the CO group. Biochemical results revealed differences between groups in TP, GLU and UREA values (p < 0.05). As a result of this study, it was determined that the topical use of common centaury oil accelerated wound healing, while laurel seed oil adversely affected wound healing in the experimental excisional full-thickness skin wound model in rats.

Dasatinib Ointment Promotes Healing of Murine Excisional Skin Wound.

Dasatinib, a tyrosine kinase inhibitor, has been shown to produce anti-inflammatory activity and impair vascular integrity in vivo, including during skin wound healing, potentially promoting the repair process. Given that dasatinib is a lipophilic small molecule capable of penetrating skin, topical dasatinib might provide benefits in wound healing. In the present study, we investigated the impact of dasatinib ointments in skin wound healing in mice. A full thickness excisional skin wound (4 mm diameter) was generated on the shaved dorsum of eight-week-old C57BL/6 mice. Dasatinib ointment (0.1 or 0.2% w/w) or ointment base was applied twice daily (every 12 h) for 10 days. Elizabethan collars were used to prevent animal licking. The wound size was monitored daily for 14 days. The results showed that dasatinib ointments, particularly 0.1% dasatinib, promoted a 16-23% reduction in wound size (p < 0.05) during day 2 to day 6 postinjury compared to controls. Immunohistochemistry analyses demonstrated a reduction in wound neutrophils (38% reduction, p = 0.04), macrophages (47% reduction, p = 0.005), and tumor necrosis factor-α levels (73% reduction, p < 0.01), together with an induction of vascular leakage-mediated fibrin(ogen) accumulation (2.5-fold increase, p < 0.01) in the wound during day 3 postinjury (an early phase of repair) in 0.1% dasatinib-treated mice relative to control mice. The anti-inflammatory and vascular hyperpermeability activities of dasatinib were associated with an enhanced healing process, including increased keratinocyte proliferation (1.8-fold increase in Ki67+ cells, p < 0.05) and augmented angiogenesis (1.7-fold increase in CD31+ area, p < 0.05), compared to the ointment base-treated group. Following treatment with 0.2% dasatinib ointment, minor wound bleeding and scab reformation were observed during the late phase, which contributed to delayed healing. In conclusion, our data suggest that dasatinib ointment, mainly at 0.1%, promotes the repair process by reducing inflammation and producing a local and temporal vascular leakage, leading to an increase in fibrin(ogen) deposition, re-epithelialization, and angiogenesis. Therefore, topical dasatinib might be a potential novel candidate to facilitate skin wound healing.

Continuous NPWT Regulates Fibrosis in Murine Diabetic Wound Healing.

Scarring is associated with significant morbidity. The mechanical signaling factor yes-associated protein (YAP) has been linked to Engrailed-1 (En1)-lineage positive fibroblasts (EPFs), a pro-scarring fibroblast lineage, establishing a connection between mechanotransduction and fibrosis. In this study, we investigate the impact of micromechanical forces exerted through negative pressure wound therapy (NPWT) on the pathophysiology of fibrosis. Full-thickness excisional dorsal skin wounds were created on diabetic (db/db) mice which were treated with occlusive covering (control) or NPWT (continuous, −125 mmHg, 7 days; NPWT). Analysis was performed on tissue harvested 10 days after wounding. NPWT was associated with increased YAP (p = 0.04) but decreased En1 (p = 0.0001) and CD26 (p < 0.0001). The pro-fibrotic factors Vimentin (p = 0.04), α-SMA (p = 0.04) and HSP47 (p = 0.0008) were decreased with NPWT. Fibronectin was higher (p = 0.01) and collagen deposition lower in the NPWT group (p = 0.02). NPWT increased cellular proliferation (p = 0.002) and decreased apoptosis (p = 0.03). Western blotting demonstrated increased YAP (p = 0.02) and RhoA (p = 0.03) and decreased Caspase-3 (p = 0.03) with NPWT. NPWT uncouples YAP from EPF activation, through downregulation of Caspace-3, a pro-apoptotic factor linked to keloid formation. Mechanotransduction decreases multiple pro-fibrotic factors. Through this multifactorial process, NPWT significantly decreases fibrosis and offers promising potential as a mode to improve scar appearance.

Egg yolk oil accelerates wound healing in streptozotocin induced diabetic rats

ABSTRACT Impaired diabetic wound healing causes foot ulcers. We investigated egg yolk oil for skin wound healing in streptozotocin (STZ) induced diabetic rats. Rats were allocated into three groups of six. Group 1, nondiabetic control group, was treated topically with 2% fusidic acid ointment. Group 2, STZ diabetic control, was treated topically with 2% fusidic acid ointment. Group 3, STZ diabetic group, was treated topically with egg yolk oil. Three days after STZ injection, two full thickness excisional skin wounds were created on the back of each animal. Wound diameter was measured for 14 days and wound contraction was calculated. Re-epithelization time also was determined. Three rats from each group were sacrificed on experimental day 7 and the remaining rats on day 14. Wound samples were examined using hematoxylin and eosin, periodic acid-Schiff, Masson’s trichrome, Taenzer-Unna orcein and toluidine blue staining. Expression of endoglin (CD105), epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) were investigated using immunohistochemistry. Egg yolk oil increased the proliferation of epithelial cells and angiogenesis, and stimulated collagen deposition in the lesion area. Egg yolk oil increased CD105, EGF and VEGF expression in blood vessels, and EGF and VEGF expression in epidermis of the lesions. The predominant fatty acids in egg yolk oil are oleic, palmitic and linoleic, which likely were responsible for the beneficial effects of egg yolk oil on diabetic wound healing. Egg yolk oil appears to be a promising therapeutic agent for healing of diabetic wounds.

Comparative studies on the effect of pig adipose-derived stem cells (pASCs) preconditioned with hypoxia or normoxia on skin wound healing in mice

Adipose-derived stem cells (ASCs) from human and animal fat have emerged as therapeutic alternatives for damaged tissues. Pre-conditioning of ASCs with hypoxia results in their functional enhancement, which might facilitate the process of healing. However, there is still a critical need for large-scale preclinical studies to reinforce the translation of these findings into clinical practice for humans and in veterinary medicine. Here, we adapted a full-thickness excisional skin wound mouse model to evaluate and compare the effect of pig adipose-derived stem cells (pASCs) cultured under normoxia (pASCs-Nor) or hypoxia (pASCs-Hyp) on the healing process. We show that pASCs-Hyp accelerated re-epithelialization, increased hyaluronic acid (HA) content, and decreased scar elevation index (SEI) during the late stage of healing (day 21). Transplantation of pASCs-Hyp also promoted expression of angiogenic marker VegfA and decreased levels of pro-scarring Tgfβ1. Mice tolerated xenotransplantation of the pASCs with no impact on macrophage (CD68 -positive cell) content. However, wounds treated with pASCs-Hyp exhibited decreased elasticity at the early stage of healing and increased expression of Wnt signaling members including Wnt10a, Wnt11, and β-catenin, which are associated with scar-forming wound repair. In conclusion, pASCs treatment may provide a critical step toward the evaluation of pASCs as therapeutically relevant cells in the context of wound healing.

P34. CONTINUOUS NEGATIVE PRESSURE WOUND THERAPY REGULATES HEALING AND FIBROSIS IN MURINE EXCISIONAL WOUNDS

PURPOSE: Hypertrophic scarring is a fibroproliferative disorder that can occur post-operatively resulting in significant functional and esthetic morbidity. Mechanical forces are known to modify the wound microenvironment and influence cellular behavior and organization. The potential effects of micromechanical force application through Negative Pressure Wound Therapy (NPWT) on skin scarring have not yet been explored in vivo. Here we investigate the application of continuous NPWT in a murine excisional wound model. METHODS: 20 obese and diabetic (db/db) mice received a 1×1 cm2 full thickness excisional dorsal skin wound and were separated into two groups, treated either with occlusive covering (Control, n=10), or NPWT (continuous, -125 mmHg, 7 days; NPWT, n=10). The wounds were photographed on days 0, 7, and 10, and the animals sacrificed and tissue harvested on day 10 for histological and molecular analysis. RESULTS: Although use of NPWT was shown to significantly increase Yes-associated protein (YAP), Engrailed-1 (En1) was significantly decreased. Use of NPWT significantly increased fibronectin deposition and improved collagen deposition and organization. Western blotting showed significantly increased RhoA and YAP and decreased Caspase-3 in the NPWT group. CONCLUSION: Taken together, our findings indicate that the mechanotransduction forces exerted by NPWT uncouple YAP, a mechanical signaling protein, from En1. Fibroblasts of an En1 lineage are known to mediate fibrotic processes that lead to scarring, while increased expression of caspase-3 has been linked to keloid formation. Therefore, through its actions on fibroblast proliferation and apoptosis, NPWT may play a significant role in final scar appearance.

Supraphysiological testosterone supplementation improves granulation tissue maturation through angiogenesis in the early phase of a cutaneous wound healing model in rats.

The aim of this study was to evaluate the effects of both testosterone depletion and supraphysiological testosterone supplementation in the early phase of an animal cutaneous wound healing model in comparison with the physiological hormonal condition. Forty rats were distributed into the following four groups: Control, Orchiectomy (OCX), Durateston (Dura) and OCX+Dura. On day 1, the testicles were removed (OCX group) and the rats (Dura group) received a supraphysiological dose (250 mg/kg) of exogenous testosterone weekly. After 15 days a full-thickness excisional skin wound was created in all animals, which was healed by the second intention for 7 days. On day 22, the rats were euthanatized and the wounds were harvested for histopathological evaluation, immunohistochemistry analyses and multiplex immunoassay. One-way ANOVA and post-hoc Tukey tests were performed. It was found that the supraphysiological testosterone level increased extracellular matrix deposition, promoted higher blood vessel formation and reduced wound contraction (p < 0.05). Additionally, it also stimulated PCNA-positive fibroblasts and KGF-positive cells (p < 0.05), while orchiectomy reduced the expression of IL-6 and TNF-α and increased VEGF and PDGF (p < 0.05) . In conclusion, the results provide evidence that supraphysiological testosterone supplementation plays a positive role in the early phase of cutaneous wound healing, thus improving granulation tissue maturation through the enhancement of angiogenesis.

Wound-Healing Potential of Rhoifolin-Rich Fraction Isolated from Sanguisorba officinalis Roots Supported by Enhancing Re-Epithelization, Angiogenesis, Anti-Inflammatory, and Antimicrobial Effects.

A wound is a complicated bioprocess resulting in significant tissue damage, which is worsened by a secondary bacterial infection, commonly Pseudomonas aeruginosa and Staphylococcus aureus. The goal of our study was to investigate the metabolic profile and possible wound-healing effect of Sanguisorba officinalis roots rhoifolin rich fraction (RRF). The LC-ESI-MS/MS analysis of S. officinalis roots crude ethanol extract resulted in a tentative identification of 56 bioactive metabolites, while a major flavonoid fraction was isolated by column chromatography and identified by thin-layer chromatography coupled with electrospray ionization/mass spectrometry (TLC-ESI/MS), where rhoifolin was the major component representing 94.5% of its content. The antibiofilm activity of RRF on the mono-species and dual-species biofilm of P. aeruginosa and S. aureus was investigated. RRF exhibited inhibitory activity on P. aeruginosa and S. aureus mono-species biofilm at 2× minimum inhibitory concentration (MIC) and 4× MIC values. It also significantly inhibited the dual-species biofilm at 4× MIC values. Moreover, the wound-healing characteristics of RRF gel formulation were investigated. Rats were randomly allocated into four groups (eight rats in each): Untreated control; Blank gel; Betadine cream, and RRF gel groups. Animals were anesthetized, and full-thickness excisional skin wounds were created on the shaved area in the dorsal skin. The gels were topically applied to the wound’s surface daily for 10 days. The results demonstrated that RRF had a promising wound-healing effect by up-regulating the platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF), keratinocyte growth factor (KGF), and fibronectin, while metalloproteinase-1 (MMP-1), interleukin-6 (IL-6), IL-1β, and nitric oxide (NO) levels were suppressed. It also enhanced the immune staining of transforming growth factor (TGF-β) and improved histopathological findings. Furthermore, it displayed an immunomodulatory action on lipopolysaccharide-induced peripheral blood mononuclear cells. Hence, the wound-healing effect of rhoifolin was confirmed by supporting re-epithelization, angiogenesis, antibacterial, immunomodulatory, and anti-inflammatory activities.

Multifunctional Elastin-Like Polypeptide Fusion Protein Coacervates Inhibit Receptor-Mediated Proinflammatory Signals and Promote Angiogenesis in Mouse Diabetic Wounds.

Objective: Chronic skin wounds are one of the most devastating complications in diabetic patients due to the formation of advanced glycation end-products (AGEs) resulting from nonenzymatic glycation of proteins and lipids in hyperglycemia. AGEs, upon binding their receptors (RAGEs), trigger proinflammatory signals that impair wound healing in diabetes and contribute to the pathology of chronic skin wounds. Approach: We previously developed a recombinant fusion protein containing the binding domain of RAGE (vRAGE) linked to elastin-like polypeptides (ELPs) that acts as a competitive inhibitor of AGEs, and another ELP fusion protein containing stromal cell-derived factor 1 (SDF1) that promotes revascularization. In this study, we report the effects of protein coacervates incorporating both vRAGE-ELP and SDF1-ELP on wound healing in an in vitro diabetes-mimicking cell culture system, and in in vivo in full-thickness wounds on diabetic mice. Results: The combination of vRAGE-ELP and SDF1-ELP increased cell metabolic activity in AGE-stimulated endothelial cells, promoted in vitro tube formation and accelerated healing in an in vitro cell migration assay. When used in a single topical application on full-thickness excisional skin wounds in diabetic mice, wound closure in the combination groups reached almost 100% on postwounding day 35, compared to 62% and 85% on the same days in animals treated with fibrin gel control and vehicle control consisting of ELP alone. Innovation: To our knowledge, this is the first study that attempts to reverse the AGE-RAGE-mediated signaling as well as to promote cell proliferation and vascularization in one single treatment. Conclusion: The codelivery of vRAGE-ELP and SDF1-ELP has potential for the treatment of diabetic wounds.

Topical Administration of an Ointment Prepared From Satureja sahendica Essential Oil Accelerated Infected Full-Thickness Wound Healing by Modulating Inflammatory Response in a Mouse Model

Satureja sahendica has antibacterial and anti-inflammatory properties that can have beneficial effects for decreasing inflammation in infected wounds. This study was conducted to evaluate the effects of an ointment prepared from S sahendica essential oil (SSO) on an infected wound model in BALB/c mice. One full-thickness excisional skin wound was surgically created per animal and inoculated with 5 × 107 colony-forming units of Pseudomonas aeruginosa and Staphylococcus aureus. Following induction of the wound, the mice (N = 90) were treated with soft yellow paraffin (negative control, n = 18), mupirocin (positive control, n = 18) and 1%, 2%, and 4% SSO (n = 18 in each of the 3 groups). To determine the effect of the treatments on healing of an infected wound, the following factors were assessed: rate of the wound area, tissue bacterial count, histopathology, collagen biosynthesis, immunohistochemistry, and the expressions of insulin-like growth factor (IGF)-1, fibroblast growth factor (FGF)-2, vascular endothelial growth factor (VEGF), interleukin (IL)-1ß, IL-4, transforming growth factor beta (TGF-ß), and chemokine (CXC motif) ligand 1 (CXCL-1) on days 3, 7, and 14 after induction of the wound. Topical administration of SSO shortened the inflammatory phase, accelerated cellular proliferation, and increased fibroblast distribution per 1 mm2, collagen deposition, and rapid reepithelialization in comparison with control animals (P <.05). The messenger RNA levels of IGF-1, IL-10, FGF-2, VEGF, TGF-ß1, and CXCL-1 were remarkably increased, and IL-1ß level decreased (P <.05) in the treated animals compared with the control group (P <.05). The immunohistochemical analyses showed topical administration of SSO increased collagen biosynthesis in the treated group (P <.05). Topical administration of SSO shows evidence of accelerating wound healing by upregulating the expression of IGF-1, IL-10, FGF-2, VEGF, TGF-ß, and CXCL-1; shortening the inflammatory stage; and promoting the proliferative phase.

Development and Evaluation of the Wound Healing Effect of a Novel Topical Cream Formula Based on Ginkgo biloba Extract on Wounds in Diabetic Rats.

Despite advances in diabetes care, impaired diabetic wound healing remains a significant clinical problem. The present study was aimed at developing a novel cream based on Ginkgo biloba extract and investigating its wound healing effect on full-thickness wounds in diabetic rats. The topical formulated oil-in-water emulsion-based cream contains Ginkgo biloba aqueous extract in an amount of about 1% to 5% as an active agent. The prepared formula was subjected to physicochemical assessment and pharmacotechnical characterization. Eighteen alloxan-induced diabetic rats completing full-thickness excisional skin wounds were randomly divided into three groups topically treated with either a normal saline (control group), the reference drug (“Cytol Centella cream®”), and cream based on the Ginkgo biloba extract. The response to treatment was assessed by macroscopic, qualitative, and quantitative histopathological analysis. The prepared formula showed good physicochemical properties. The rheological behavior of the prepared cream followed a non-Newtonian pseudoplastic pattern at different storage temperatures. The cream, which is a macroemulsion with uniform size distribution, remained stable for 6 months. Skin tolerance studies confirmed the compatibility of the cream with the skin. During the experimental trial, the cream based on the Ginkgo biloba-treated group showed significant improvements over the control and reference groups for both general wound appearance and healing dynamics. This increased rate of closure of wounds in diabetic rats was associated with increased collagen synthesis. Our findings showed that the cream could be a promising and innovative topical treatment with Ginkgo biloba extract for the management of acute diabetic wounds.

Pro-pigmentary action of 5-fluorouracil through the stimulated secretion of CXCL12 by dermal fibroblasts.

Background:There is growing evidence that 5-fluorouracil (5-FU) combined with therapeutic trauma can effectively induce skin repigmentation in vitiligo patients who are unresponsive to conventional treatments. Previous studies have mainly focused on identifying the antimitotic activity of 5-FU for the treatment of skin cancer, but few studies have investigated its extra-genotoxic actions favoring melanocyte recruitment.Methods:We utilized the full thickness excisional skin wound model in Dct-LacZ transgenic mice to dynamically assess the migration of melanocytes in the margins of wounds treated with or without 5-FU. The in-situ expression of CXCL12 was examined in the wound beds using immunofluorescence staining. Quantitative real-time polymerase chain reaction and Western blotting analyses were performed to detect the expression levels of CXCL12 mRNA and protein in primary mouse dermal fibroblasts treated with or without 5-FU. Transwell assays and fluorescein isothiocyanate (FITC)-phalloidin staining were used to observe cell migration and filamentous actin (F-actin) changes of melan-a murine melanocytes.Results:Whole mount and cryosection X-gal staining showed that the cell numbers of LacZ-positive melanocytes were much higher in the margins of dorsal and tail skin wounds treated with 5-FU compared with the controls. Meanwhile, CXCL12 immunostaining was significantly increased in the dermal compartment of wounds treated with 5-FU (control vs. 5-FU, 22.47 ± 8.85 vs. 44.69 ± 5.97, P < 0.05). Moreover, 5-FU significantly upregulated the expression levels of CXCL12 mRNA (control vs. 5-FU, 1.00 ± 0.08 vs. 1.54 ± 0.06, P < 0.05) and protein (control vs. 5-FU, 1.00 ± 0.06 vs. 2.93 ± 0.10, P < 0.05) in cultured fibroblasts. Inhibition of the CXCL12/CXCR4 axis suppressed melanocyte migration in vitro using a CXCL12 small interfering RNA (siRNA) or a CXCR4 antagonist (AMD3100).Conclusion:5-FU possesses a pro-pigmentary activity through activation of the CXCL12/CXCR4 axis to drive the chemotactic migration of melanocytes.

Isatis glauca subsp. sivasica extract contributes to diabetic wound healing process via increased collagen and nitric oxide content

Isatis L. genus highly endemic and that is traditionally suggested for wound management in Turkey. In this study, we have reported the effect of I. glauca subsp. sivasica extract on diabetic wound healing process. A diabetic model was generated in Wistar rats using streptozotocin injection. Rats were divided into two main groups: control group and Isatis group. Full thickness excisional skin wounds were created by using a biopsy punch. The Isatis group was treated with single daily dose I. glauca subsp. sivasica extract (50 mg/kg). Rats were sacrificed day 3 or 7 after wounding. The dominant phenolic compounds identified with RP-HPLC-DAD from Isatis extract were the benzoic acid and vanillic acid. Isatis extract significantly accelerated wound healing process considering the wound closure rates (WCR). Moreover, the levels of collagen and nitric oxide were elevated on days 3 and 7 by Isatis administration in the diabetic wound tissue. These data suggest that, for the first time, I. glauca subsp. sivasica extract may have the potential to promote the impaired wound healing in patients with diabetes.

Oxidative and local histopathological response on skin wound of horses due to Amblyomma sculptum tick parasitism

Amblyomma sculptum is frequently observed parasitizing horses, responsible for economic losses, damage to the host’'s skin and transmission of pathogens. The oxidative stress profile and inflammatory mechanisms involved in this parasitism remain poorly studied. Thus, this study aimed to assess the histopathological changes and oxidative profile responses of horses in the attachment site of A. sculptum to find variations that indicate resistance and susceptibility between the breeds to this tick, based on the hypothesis that resistant animals have a greater inflammatory response and lesser number of attached ticks. We analyzed female horses of two breeds, Mangalarga Marchador and Breton Postier, naturally infested by Amblyomma sculptum. The ticks were counted and full-thickness excisional skin wounds of 10 mm were made on the perineal region on the attachment site of partially engorged females for histological and biochemical analyzes. The occurrence of the tick on the skin caused an increase in cellularity, inflammatory infiltrate, mast cells, pyknotic nuclei, and changes in the fibrous components of the matrix. The negative correlation observed between tick infestation and inflammatory response indicated that animals with greater inflammatory response tend to have less tick infestation. The oxidative stress markers, MDA, PCN and NO not present great variation; however, between the antioxidant enzymes levels, SOD was higher in tick attachment of Breton Postier skin, this may mean that these animals had higher oxidative enzymatic activity and consequently less tissue damage, while the GST dropped in the attachment sites compared to the control, which may indicate that animals were in a state of significant oxidative stress or raises the question of the possibility of enzymatic sequestration by ticks. No significant differences were found in the resistance of the two breeds since most of the analyzes varied due to the presence or absence of the tick attached to the skin. We draw attention to the importance of studying characteristics of the animal's antioxidant responses to the tick and the action of tick saliva on antioxidant enzymes and ROS because these characteristics are interdependent with the inflammatory response.

Self-assembled elastin-like polypeptide fusion protein coacervates as competitive inhibitors of advanced glycation end-products enhance diabetic wound healing

Chronic and non-healing skin wounds are some of the most significant complications in patients with advanced diabetes. A contributing mechanism to this pathology is the non-enzymatic glycation of proteins due to hyperglycemia, leading to the formation of advanced glycation end products (AGEs). AGEs bind to the receptor for AGEs (RAGE), which triggers pro-inflammatory signals that may inhibit the proliferative phase of wound healing. Soluble forms of RAGE (sRAGE) may be used as a competitive inhibitor of AGE-mediated signaling; however, sRAGE is short-lived in the highly proteolytic wound environment. We developed a recombinant fusion protein containing the binding domain of RAGE (vRAGE) linked to elastin-like polypeptides (ELPs) that self-assembles into coacervates at around 30–31 °C. The coacervate size was concentration and temperature-dependent, ranging between 500 and 1600 nm. vRAGE-ELP reversed several AGE-mediated changes in cultured human umbilical vein endothelial cells, including a decrease in viable cell number, an increase in levels of reactive oxygen species (ROS), and an increased expression of the pro-inflammatory marker, intercellular adhesion molecule-1 (ICAM-1). vRAGE-ELP was stable in elastase in vitro for 7 days. When used in a single topical application on full-thickness excisional skin wounds in diabetic mice, wound closure was accelerated, with 90% and 100% wound closure on post-wounding days 28 and 35, respectively, compared to 62% and 85% on the same days in animals treated with vehicle control, consisting of ELP alone. This coacervate system topically delivering a competitive inhibitor of AGEs has potential for the treatment of diabetic wounds.

Accelerative effect of topical Zataria multiflora essential oil against infected wound model by modulating inflammation, angiogenesis, and collagen biosynthesis

Context Zataria multiflora Boiss (Lamiaceae) essential oil (ZME) is believed to be a bactericide herbal medicine and might alleviate negative effects of infection. Objective This study evaluates the effects of an ointment prepared from ZME (ZMEO) on infected wounds. Materials and methods A full-thickness excisional skin wound was surgically created in each mouse and inoculated with 5 × 107 suspension containing Pseudomonas aeruginosa and Staphylococcus aureus. The BALB/c mice (n = 72) were divided into four groups: (1) negative control that received base ointment (NCG), (2) positive control that daily received Mupirocin® (MG), (3) therapeutic ointment containing 2% ZMEO and (4) therapeutic ointment containing 4% ZMEO, for 21 days. Wound contraction, total bacterial count, histopathological parameters, antioxidant activity, qRT-PCR analysis for expression of IL-1β, TNF-α, VEGF, IGF-1, TGF-β, IL-10, and FGF-2 mRNA levels were assessed on days 3, 7, and 14 following the wounding. Results Topical administration of ZMEO significantly decreased the total bacterial count and wound area and also expression of IL-1β and TNF-α compared to the control groups (p < 0.05) in all days. This could also increase significantly the expression of TGF-β, IL-10 IGF-1, FGF-2, and VEGF, and also angiogenesis, fibroblasts, fibrocytes, epithelialization ratio, and collagen deposition and improve antioxidant status compared to the control group (p < 0.05). Discussion and conclusion ZMEO accelerated the healing process of infected wounds by shortening the inflammatory factors and increasing proliferative phase. Applying ZMEO only and/or in combination with chemical agents for the treatment of wound healing could be suggested.

Evaluation of fish skin as a biological dressing for metacarpal wounds in donkeys

BackgroundThe use of biological dressings has recently emerged in the management of burns and wounds. The aim of the present study was to evaluate the Nile tilapia skin as a biological dressing for full-thickness cutaneous metacarpal wounds in donkeys. The study was conducted on nine clinically healthy donkeys (n = 9). Here, fish skin dressings were obtained from fresh Nile tilapia (Oreochromis niloticus and sterilized by immersion in silver nanoparticles (AgNPs) solution for 5 min, with no change in collagen content. Bilateral, circular full-thickness excisional skin wounds (2 cm in diameter) were created on the dorsal aspect of the mid-metacarpals of each donkey. Wounds on the right metacarpals (treated wounds, n = 9) were dressed with sterile fish skins, while wounds on the left metacarpals (control wounds, n = 9) were dressed with sterile non-adherent dressing pads without any topical applications. Wound dressings were changed weekly. Wounds were evaluated microbiologically, grossly, and histologically on days 7, 14, and 21 post-wound inductions.ResultsFish skin-dressed wounds showed a significant (P < 0.0001) reduction in microbial counts (Total viable bacterial count, Staphylococcal count, and Coliform count), a significant (P < 0.0001) decrease in the wound size, and a significant reduction (P < 0.0001) in the epithelial gap compared to the untreated wounds. No frequent dressing changes were needed.ConclusionsFish skin dressing accelerated the wound healing process and efficiently inhibited the local microbial activity and exuberant granulation tissue formation suggesting its reliable and promising application for metacarpal wounds of donkeys.

Extracellular vesicle-enclosed miR-486-5p mediates wound healing with adipose-derived stem cells by promoting angiogenesis.

Adipose‐derived stem cells (ASC) are said to have a pivotal role in wound healing. Specifically, ASC‐secreted extracellular vesicles (EV) carry diverse cargos such as microRNAs (miRNAs) to participate in the ASC‐based therapies. Considering its effects, we aimed to investigate the role of ASC‐EVs in the cutaneous wound healing accompanied with the study on the specific cargo‐medicated effects on wound healing. Two full‐thickness excisional skin wounds were created on mouse dorsum, and wound healing was recorded at the indicated time points followed by histological analysis and immunofluorescence staining for CD31 and α‐SMA. Human skin fibroblasts (HSFs) and human microvascular endothelial cells (HMECs) were co‐cultured with EVs isolated from ASC (ASC‐EVs), respectively, followed by the evaluation of their viability and mobility using CCK‐8, scratch test and transwell migration assays. Matrigel‐based angiogenesis assays were performed to evaluate vessel‐like tube formation by HMECs in vitro. ASC‐EVs accelerated the healing of full‐thickness skin wounds, increased re‐epithelialization and reduced scar thickness whilst enhanced collagen synthesis and angiogenesis in murine models. However, miR‐486‐5p antagomir abrogated the ASC‐EVs‐induced effects. Intriguingly, miR‐486‐5p was found to be highly enriched in ASC‐EVs, exhibiting an increase in viability and mobility of HSFs and HMECs and enhanced the angiogenic activities of HMECs. Notably, we also demonstrated that ASC‐EVs‐secreted miR‐486‐5p achieved the aforesaid effects through its target gene Sp5. Hence, our results suggest that miR‐486‐5p released by ASC‐EVs could be a critical mediator to develop an ASC‐based therapeutic strategy for wound healing.