Deferoxamine modulates cytokines and growth factors to accelerate cutaneous wound healing in diabetic rats

Preconditioning Strategies for Improving the Outcome of Fat Grafting

Autologous fat grafting is a common procedure in plastic, reconstructive, and aesthetic surgery. However, it is frequently associated with an unpredictable resorption rate of the graft depending on the engraftment kinetics. This, in turn, is determined by the interaction of the grafted adipose tissue with the tissue at the recipient site. Accordingly, preconditioning strategies have been developed following the principle of exposing these tissues in the pretransplantation phase to stimuli inducing endogenous protective and regenerative cellular adaptations, such as the upregulation of stress-response genes or the release of cytokines and growth factors. As summarized in the present review, these stimuli include hypoxia, dietary restriction, local mechanical stress, heat, and exposure to fractional carbon dioxide laser. Preclinical studies show that they promote cell viability, adipogenesis, and angiogenesis, while reducing inflammation, fibrosis, and cyst formation, resulting in a higher survival rate and quality of fat grafts in different experimental settings. Hence, preconditioning represents a promising approach to improve the outcome of fat grafting in future clinical practice. For this purpose, it is necessary to establish standardized preconditioning protocols for specific clinical applications that are efficient, safe, and easy to implement into routine procedures.

Single dose human perinatal stem cells accelerate healing of cold-induced rat burn wound

Temporal phases of wound healing and their corresponding healing factors are essential in wound regeneration. Mesenchymal stem cells (MSCs) accelerate wound healing via their paracrine secretions by enhancing cell migration, angiogenesis, and reducing inflammation. This study evaluated the local therapeutic effect of human umbilical cord MSCs (hUCMSCs) in the healing of cold-induced burn wounds. An in vitro wound (scratch) was developed in rat skin fibroblasts. The culture was maintained in the conditioned medium (CM) which was prepared by inducing an artificial wound in hUCMSCs in a separate experiment. Treated fibroblasts were analyzed for the gene expression profile of healing mediators involved in wound closure. Findings revealed enhanced cell migration and increased levels of healing mediators in the treated fibroblasts relative to the untreated group. Cold-induced burn wounds were developed in Wistar rats, followed by a single injection of hUCMSCs. Wound healing pattern was examined based on the healing phases: hemostasis/inflammation (Days 1, 3), cell proliferation (Day 7), and remodeling (Day 14). Findings exhibited enhanced wound closure in the treated wound. Gene expression, histological, and immunohistochemical analyses further confirmed enhanced wound regeneration after hUCMSC transplantation. Temporal gene expression profile revealed that the level of corresponding cytokines was substantially increased in the treated wound as compared with the control, indicating improvement in the processes of angiogenesis and remodeling, and a substantial reduction in inflammation. Histology revealed significant collagen formation along with regenerated skin layers and appendages, whereas immunohistochemistry exhibited increased neovascularization during remodeling. Leukocyte infiltration was also suppressed in the treated group. Overall findings demonstrate that a single dose of hUCMSCs enhances wound healing in vivo, and their secreted growth factors accelerate cell migration in vitro.

Insights into the mechanisms of diabetic wounds: pathophysiology, molecular targets, and treatment strategies through conventional and alternative therapies

Diabetes mellitus is a prevalent cause of mortality worldwide and can lead to several secondary issues, including DWs, which are caused by hyperglycemia, diabetic neuropathy, anemia, and ischemia. Roughly 15% of diabetic patient's experience complications related to DWs, with 25% at risk of lower limb amputations. A conventional management protocol is currently used for treating diabetic foot syndrome, which involves therapy using various substances, such as bFGF, pDGF, VEGF, EGF, IGF-I, TGF-β, skin substitutes, cytokine stimulators, cytokine inhibitors, MMPs inhibitors, gene and stem cell therapies, ECM, and angiogenesis stimulators. The protocol also includes wound cleaning, laser therapy, antibiotics, skin substitutes, HOTC therapy, and removing dead tissue. It has been observed that treatment with numerous plants and their active constituents, including Globularia Arabica, Rhus coriaria L., Neolamarckia cadamba, Olea europaea, Salvia kronenburgii, Moringa oleifera, Syzygium aromaticum, Combretum molle, and Myrtus communis, has been found to promote wound healing, reduce inflammation, stimulate angiogenesis, and cytokines production, increase growth factors production, promote keratinocyte production, and encourage fibroblast proliferation. These therapies may also reduce the need for amputations. However, there is still limited information on how to prevent and manage DWs, and further research is needed to fully understand the role of alternative treatments in managing complications of DWs. The conventional management protocol for treating diabetic foot syndrome can be expensive and may cause adverse side effects. Alternative therapies, such as medicinal plants and green synthesis of nano-formulations, may provide efficient and affordable treatments for DWs.

The potential role of ferroptosis in the physiopathology of deep tissue injuries

Deep tissue injuries (DTIs) are a serious type of pressure injuries that mainly occur at the bony prominences and can develop rapidly, making prevention and treatment more difficult. Although consistent research efforts have been made over the years, the cellular and molecular mechanisms contributing to the development of DTIs remain unclear. More recently, ferroptosis, a novel regulatory cell death (RCD) type, has been identified that is morphological, biochemical and genetic criteria distinct from apoptosis, autophagy and other known cell death pathways. Ferroptosis is characterized by iron overload, iron-dependent lipid peroxidation and shrunken mitochondria. We also note that some of the pathological features of DTI are known to be key features of the ferroptosis pathway. Numerous studies have confirmed that ferroptosis may be involved in chronic wounds, including DTIs. Here, we elaborate on the basic pathological features of ferroptosis. We also present the evidence that ferroptosis is involved in the pathology of DTIs and highlight a future perspective on this emerging field, desiring to provide more possibilities for the prevention and treatment of DTIs.

Advances in Hypoxia-Inducible Factor-1α Stabilizer Deferoxamine in Tissue Engineering

Deferoxamine (DFO) is an iron chelator with FDA approval for the clinical treatment of iron excess. As a well-established stabilizer of hypoxia-inducible factor-1α (HIF-1α), DFO can efficiently upregulate HIF-1α and relevant downstream angiogenic factors, leading to accelerated vascularization. Moreover, as increasing studies have focused on DFO as a hypoxia-mimetic agent in recent years, it has been shown that DFO exhibited multiple functions, including stem cell regulation, immunoregulation, provascularization, and pro-osteogenesis. On the contrary, DFO can bind excess iron ions in wounds of chronic inflammation, while serving as an antioxidant with the characteristic of removing reactive oxygen species. Collectively, these characteristics make DFO a potent modulator in tissue engineering for increasing tissue integration of biomaterials in vivo and facilitating wound healing. This review outlines the activity of DFO as a representative hypoxia-mimetic agent in cells as well as the evolution of its application in tissue engineering. It can be concluded that DFO is a medication with tremendous promise and application value in future trends, which can optimize biomaterials and existing tissue engineering techniques for tissue regeneration.

Pterostilbene attenuates hemin-induced dysregulation of macrophage M2 polarization via Nrf2 activation in experimental hyperglycemia

Macrophages exhibit a high degree of plasticity that is physiologically relevant in wound healing, and disruption in normal macrophage response leads to delayed wound closure resulting in chronic wounds. Here, we attempt to discern macrophage responses to hemin via regulation of the nuclear factor-erythroid factor 2-related factor 2 (Nrf2) that could help us better understand the pathophysiology of diabetic foot ulcers (DFU). We demonstrate the alleviation of hemin-mediated Nrf2 suppression and M2 macrophage polarization by pterostilbene (PTS), a proven Nrf2 activator. IC-21 macrophages were treated with hemin under the normoglycemic or hyperglycemic environment with or without PTS and the expression levels of various markers, such as Nrf2 and its downstream target Heme Oxygenase-1 (HO-1), CD206, Ferroportin-1 among others were analyzed using qPCR and Western blot. Our results revealed that hemin under hyperglycemia reduced Nrf2 activation and its downstream targets, M2 polarization, and the induction of a proinflammatory cellular environment, and interestingly all of these were remedied by PTS treatment. Gelatin zymography of matrix metalloproteinase2 (MMP2) expression revealed that hemin under hyperglycemic condition significantly elevated MMP2 expression, which was reversed by PTS treatment. Further proteomic analysis using liquid chromatography with tandem mass spectrometry (LC-MS/MS) revealed a heightened cellular stress profile accompanying inflammation that was suppressed by PTS. This study has furthered our understanding on the role of Nrf2 in attenuating hemin-induced perturbations in macrophage responses and suggests a potential therapeutic target in the management of DFU.

An antibacterial and proangiogenic double-layer drug-loaded microneedle patch for accelerating diabetic wound healing

Diabetic wounds are difficult to heal because of bacterial infections and insufficient angiogenesis. Herein, we report a double-layer drug-loaded microneedle patch with antibacterial and angiogenesis-promoting properties for diabetic wound healing. The double-layer microneedle comprises the hyaluronic acid (HA)-loaded antibacterial drug tetracycline hydrochloride (TCH) as the tip and a mixture of chitosan and silk fibroin containing the angiogenic drug deferoxamine (DFO) as the substrate. In the double-layer drug-loaded microneedle system (DMN@TCH/DFO), rapid dissolution of HA at the tip releases TCH to promote early antibacterial activity. The substrate exhibits excellent swelling properties, facilitating the absorption of tissue fluid from the wound to promote wound contraction. Simultaneously, DFO is released to promote angiogenesis. Therefore, DMN@TCH/DFO exhibited adequate mechanical properties, excellent swelling and biocompatibility, antibacterial properties, and angiogenesis-promoting capabilities. In a wound model of diabetic rats, DMN@TCH/DFO reduced inflammatory responses, promoted angiogenesis, and facilitated collagen deposition, thereby accelerating diabetic wound healing. Overall, DMN@TCH/DFO can accelerate the healing of diabetic wounds and has clinical application prospects.

Recent advances of the nanocomposite hydrogel as a local drug delivery for diabetic ulcers

Diabetic ulcer is a serious complication of diabetes. Compared with that of healthy people, the skin of patients with a diabetic ulcer is more easily damaged and difficult to heal. Without early intervention, the disease will become increasingly serious, often leading to amputation or even death. Most current treatment methods cannot achieve a good wound healing effect. Numerous studies have shown that a nanocomposite hydrogel serves as an ideal drug delivery method to promote the healing of a diabetic ulcer because of its better drug loading capacity and stability. Nanocomposite hydrogels can be loaded with one or more drugs for application to chronic ulcer wounds to promote rapid wound healing. Therefore, this paper reviews the latest progress of delivery systems based on nanocomposite hydrogels in promoting diabetic ulcer healing. Through a review of the recent literature, we put forward the shortcomings and improvement strategies of nanocomposite hydrogels in the treatment of diabetic ulcers.

Chronic wounds

Chronic wounds are characterized by their inability to heal within an expected time frame and have emerged as an increasingly important clinical problem over the past several decades, owing to their increasing incidence and greater recognition of associated morbidity and socio-economic burden. Even up to a few years ago, the management of chronic wounds relied on standards of care that were outdated. However, the approach to these chronic conditions has improved, with better prevention, diagnosis and treatment. Such improvements are due to major advances in understanding of cellular and molecular aspects of basic science, in innovative and technological breakthroughs in treatment modalities from biomedical engineering, and in our ability to conduct well-controlled and reliable clinical research. The evidence-based approaches resulting from these advances have become the new standard of care. At the same time, these improvements are tempered by the recognition that persistent gaps exist in scientific knowledge of impaired healing and the ability of clinicians to reduce morbidity, loss of limb and mortality. Therefore, taking stock of what is known and what is needed to improve understanding of chronic wounds and their associated failure to heal is crucial to ensuring better treatments and outcomes.

An Overview of Diabetic Foot Ulcers and Associated Problems with Special Emphasis on Treatments with Antimicrobials

One of the most significant challenges of diabetes health care is diabetic foot ulcers (DFU). DFUs are more challenging to cure, and this is particularly true for people who already have a compromised immune system. Pathogenic bacteria and fungi are becoming more resistant to antibiotics, so they may be unable to fight microbial infections at the wound site with the antibiotics we have now. This article discusses the dressings, topical antibacterial treatment, medications and debridement techniques used for DFU and provides a deep discussion of DFU and its associated problems. English-language publications on DFU were gathered from many different databases, such as Scopus, Web of Science, Science Direct, Springer Nature, and Google Scholar. For the treatment of DFU, a multidisciplinary approach involving the use of diagnostic equipment, skills, and experience is required. Preventing amputations starts with patient education and the implementation of new categorization systems. The microbiota involved in DFU can be better understood using novel diagnostic techniques, such as the 16S-ribosomal DNA sequence in bacteria. This could be achieved by using new biological and molecular treatments that have been shown to help prevent infections, to control local inflammation, and to improve the healing process.

Wound Healing Effects of Dracontomelon dao on Bacterial Infection Wounds in Rats and Its Potential Mechanisms under Simulated Space Environment

Dracontomelon dao (D. dao) is the leaves of Dracontomelon duperreanum Pierre (D. dao auct. non (Blanco) Merr. and Rolfe; D. sinense Stopf.). As a valuable traditional Chinese medicine from Anacardiaceae, D. dao has a long history of treating bedsores, skin ulcers, and other infection diseases. In addition, the volatile oil from D. dao leaves exhibits antitumor effects. However, these reported studies only focused on evaluating the antimicrobial efficacy on model strains in vitro, without paying attention to the antimicrobial activity and anti-inflammatory effects in vivo. This study was aimed to provide evidence of antimicrobial activity and anti-inflammatory and proangiogenesis activities of Dracontomelon dao (D. dao) on the skin of rats under simulated space environment. The weightlessness model of rats in space environment was established. Then, rats were given D. dao for 15 days. Wound healing effects of D. dao on histopathology and inflammatory cytokines in E. coli-induced wound infection in weightless rats were analyzed. Furthermore, the molecular biology technology was performed to evaluate the wound healing effects of D. dao on the relative protein level of NF-κB as well as PI3K/Akt signaling pathways. Immunohistochemistry was used for the protein expression of VEGFA. The wound healing effects of D. dao on bacterially infected wounds in rats were manifested by lowering the size of the wound and significantly increasing the shrinkage rate of the wound. D. dao had effect on alleviating histological damage of skin tissue and downregulation inflammatory cytokines level. In addition, the results indicated that D. dao has a regulatory effect on inflammation and angiogenesis and could regulate the relative protein level of MAPK/NF-κB as well as PI3K/AKT signaling pathways. The current study highlighted the crucial role of D. dao in relieving skin tissue injury in E. coli-induced wound infection in weightless rats by regulating the MAPK/NF-κB as well as PI3K/AKT signaling pathways. This study could provide a new agent for the treatment of bacterial infected wounds in simulated space environment.

Angiogenic Effect of a Nanoniosomal Deferoxamine-Loaded Poly(vinyl alcohol)-Egg White Film as a Promising Wound Dressing

Owing to the noticeable increase in the number of patients with impaired wound healing capabilities, developing bioactive wound dressings with supportive physicomechanical and biological properties for clinical wound management has attracted much more attention nowadays. In this regard, engineered dressings with angiogenesis potential are vital for accelerated tissue regeneration. In the current study, nanoniosomal deferoxamine (DFO)-loaded transparent films of egg white-poly(vinyl alcohol) (PVA/EW/ND) were successfully fabricated at three different PVA/EW ratios (1:0, 1:1, and 1:1.5 wt/wt %) through the thin film hydration and solvent casting methods. The developed films' characterizations were carried out using scanning electron microscopy, Fourier transform infrared spectroscopy analysis, uniaxial tensile strength, water uptake, water vapor transmission rate, in vitro degradation, and drug release. The results demonstrated that the various weight ratios of PVA/EW have a significant effect on the microscopic morphology, equilibrium swelling, degradation, and mechanical properties of the films. The drug release profile exhibited a sustained release of DFO with controlled burst-lag phases resembling the Korsmeyer-Peppas pattern. The cytotoxicity and adhesion analysis using human dermal fibroblasts displays the biocompatibility of the developed PVA/EW/ND films and the formation of cellular colonies on the surface. The in vitro angiogenic capability of the developed films evaluated by the scratch wound assay and microbead-assisted tube formation study showed a significant increase in the rate of migration of human umbilical vein endothelial cells and in the number of tube-like structures. Therefore, the achieved results suggest that the presented PVA/EW/ND film has promising potential for effective wound healing applications.

Nrf2 driven macrophage responses in diverse pathophysiological contexts: Disparate pieces from a shared molecular puzzle

The wide anatomical distribution of macrophages and their vast array of functions match various polarization states and their involvement in homeostasis and disease. The confluence of different cellular signaling networks, including direct involvement in inflammation, at the doorstep of the transcription factor Nuclear Factor- erythroid (NF-E2) p45-related factor 2 (Nrf2) activation raises the importance of deciphering the molecular circuitry at the background of multiple-discrete and antagonistic yet flexible and contextual pathways. While we primarily focus on wound healing and repair mechanisms that are affected in diabetic foot ulcers (DFUs), we strive to explore the striking similarities and differences in molecular events including inflammation, angiogenesis, and fibrosis during tissue injury and wound persistence that accumulates pro-inflammatory senescent macrophages, as a means to identify possible targets or cellular mediators to lessen DFU disease burden. In addition, the role of iron in the modulation of Nrf2 response in macrophages is crucial and reviewed here. Targeted approaches, unlike conventional treatments, in DFU management will require the review and re-assessment of mediators with relevance to other pathological conditions.

Diabetic foot ulcer, antimicrobial remedies and emerging strategies for the treatment

According to the International Diabetes Federation's 2015 study, diabetes affects over 415 million people globally (5 million of whom die each year), and the incidence of diabetes is expected to climb to over 640 million (1 in 10) by 2040. (IDF 2015). Diabetes foot ulcers (DFU) are one of the most significant diabetic health consequences. Antimicrobial treatments, such as dressings, topical therapies, medicines, drugs, debridement procedures, molecular, cellular, and gene therapies, plant extracts, antimicrobial peptides, growth factors, devices, ozone, and energy-based therapies, would be the focus of this study. Scopus, Web of Science, Bentham Science, Science Direct, and Google Scholar were among the sources used to compile the English-language publications on DFU. DFU treatment requires a multidisciplinary approach that includes the use of proper diagnostic tools, competence, and experience. To prevent amputations, this starts with patient education and the use of new categories to steer treatment. New diagnostic methods, such as the 16S ribosomal DNA sequence in bacteria, should become available to acquire a better knowledge of the microbiota in DFUs. 

[Early constant observation of the effect of deferoxamine mesylate on improvement of vascularized bone regeneration in SD rat skull critical size defect model]

OBJECTIVE

To investigate the effect of local administration of deferoxamine mesylate (DFO) on vascularization and osteogenesis and its ability to maintain the activity of hypoxia inducible factor-1α (HIF-1α), by constantly observing early changes of vessel-like structures and bone tissues during bone defects healing.

METHODS

Skull critical bone defect models were constructed on a total of thirty male SD rats (6-8 weeks old). The rats were randomly divided into experimental group (DFO group) or control group (normal saline group). 300 μL 200 μmol/L DFO solution or normal saline was locally injected on the 4th day after the defect was made. On the 5th, 7th, 10th, 14th, and 28th days after surgery, three rats in each group were sacrificed respectively. HE staining and Masson staining were performed to observe new bone formation and mineralization. HIF-1α immunohistochemistry staining was performed to examine relative expression of protein. Qualitative analysis and comparation were performed by t-tests on relative expression of HIF-1α, numbers of blood vessels and percentages of mineralization tissues of new bone areas.

RESULTS

On the 5th, 7th, 10th, 14th and 28th days after surgery, the average numbers of blood vessels were 30.40±12.15, 62.00±17.87, 73.43±15.63, 40.00±7.84, 48.71±11.64 in the DFO group, and 18.75±6.63, 19.13±2.80, 51.35±16.21, 27.18±7.32, 30.88±13.43 in the control group. The number of blood vessels in the DFO group was significantly higher than that of the control group at each time point (P < 0.05). The mass of new bone in the DFO group was higher than that in the control group on the 14th and 28th days after surgery. The percentage of mineralization tissues of new bone area on the 14th and 28th days after injection were (27.73±5.93)% and (46.53±3.66)% in the DFO group, and (11.99±2.02)% and (31.98±4.22)% in the control group. The percentage of mineralization tissues in the DFO group was significantly higher than that of the control group at each time point (P < 0.001). The relative expression of HIF-1α in the DFO group compared with the control group was 2.86±0.48, 1.32±0.26, 1.32±0.32, 1.28±0.38 and 1.05±0.34 on the 5th, 7th, 10th, 14th and 28th days, with significant expression difference on the 5th day (P < 0.01).

CONCLUSION

Use of DFO in bone defects promotes vascularization and osteogenesis in the defect area, and maintains the protein activity of HIF-1α temporarily.

The Use of Menthol in Skin Wound Healing-Anti-Inflammatory Potential, Antioxidant Defense System Stimulation and Increased Epithelialization

Wound healing involves inflammatory, proliferative, and remodeling phases, in which various cells and chemical intermediates are involved. This study aimed to investigate the skin wound healing potential of menthol, as well as the mechanisms involved in its effect, after 3, 7, or 14 days of treatment, according to the phases of wound healing. Skin wound was performed in the back of Wistar rats, which were topically treated with vehicle cream; collagenase-based cream (1.2 U/g); or menthol-based cream at 0.25%, 0.5%, or 1.0% over 3, 7, or 14 days. Menthol cream at 0.5% accelerated the healing right from the inflammatory phase (3 days) by decreasing mRNA expression of inflammatory cytokines TNF-α and Il-6. At the proliferative phase (7 days), menthol 0.5% increased the activity of antioxidant enzymes SOD, GR, and GPx, as well as the level of GSH, in addition to decreasing the levels of inflammatory cytokines TNF-α, IL-6, and IL-1β and augmenting mRNA expression for Ki-67, a marker of cellular proliferation. At the remodeling phase (14 days), levels of inflammatory cytokines were decreased, and the level of Il-10 and its mRNA expression were increased in the menthol 0.5% group. Menthol presented skin wound healing activity by modulating the antioxidant system of the cells and the inflammatory response, in addition to stimulating epithelialization.

Limited Treatment Options for Diabetic Wounds: Barriers to Clinical Translation Despite Therapeutic Success in Murine Models

Significance: Millions of people worldwide suffer from diabetes mellitus and its complications, including chronic diabetic wounds. To date, there are few widely successful clinical therapies specific to diabetic wounds beyond general wound care, despite the vast number of scientific discoveries in the pathogenesis of defective healing in diabetes. Recent Advances: In recent years, murine animal models of diabetes have enabled the investigation of many possible therapeutics for diabetic wound care. These include specific cell types, growth factors, cytokines, peptides, small molecules, plant extracts, microRNAs, extracellular vesicles, novel wound dressings, mechanical interventions, bioengineered materials, and more. Critical Issues: Despite many research discoveries, few have been translated from their success in murine models to clinical use in humans. This massive gap between bench discovery and bedside application begs the simple and critical question: what is still missing? The complexity and multiplicity of the diabetic wound makes it an immensely challenging therapeutic target, and this lopsided progress highlights the need for new methods to overcome the bench-to-bedside barrier. How can laboratory discoveries in animal models be effectively translated to novel clinical therapies for human patients? Future Directions: As research continues to decipher deficient healing in diabetes, new approaches and considerations are required to ensure that these discoveries can become translational, clinically usable therapies. Clinical progress requires the development of new, more accurate models of the human disease state, multifaceted investigations that address multiple critical components in wound repair, and more innovative research strategies that harness both the existing knowledge and the potential of new advances across disciplines.

Fabrication of multi-functional carbon dots based on "one stone, three birds" strategy and their applications for the dual-mode Fe3+ detection, effective promotion on cell proliferation and treatment on ferric toxicosis in vitro

The ingenious design of multi-functional materials to simultaneously achieve the accurate detection of targets and effective treatment of target-related diseases is of great significance for both practical and clinical applications. Accordingly, based on their advantages of facile synthesis and function designability, functional nanomaterials have become promising candidates for integrating multi-functionality into one platform, especially carbon dot (CD)-based materials. Herein, deferoxamine (DFO)-inspired CDs with integrated "sense and treatment" potential were elaborately designed and fabricated via a one-pot hydrothermal synthesis by employing l-aspartic acid (Asp) and 2,5-diaminobenzenesulfonic acid (DABSA) as the reactants. A series of characterization results distinctly confirmed that the synthesized CDs possessed a unique chemical composition, uniform spherical morphology (diameter of around 5 nm) and good dispersibility in aqueous solution, exhibiting excellent fluorescence stability under different conditions. Owing to the complexation interaction between Fe3+ and the functional groups of CDs, the selective and sensitive detection of Fe3+ could be successfully realized through fluorescent and colorimetric dual-mode detection based on the statistic quenching in the initial stage, and subsequently the FRET process. Furthermore, these CDs could be utilized for cellular imaging and effective Fe3+ detection due to their outstanding biocompatibility and cytoplasmatic distribution. More significantly, these DFO-inspired CDs could remarkably promote the proliferation of various mammalian cells. Particularly, the results in this work obviously indicated that this type of CDs could weaken the damage of Fe3+ towards the physiological behaviors of cells, helping the cells to regain their capability of differentiation after ferric toxicosis. Therefore, this work presents an original approach for the design and fabrication of multi-functional materials according to the "one stone, three birds" strategy, which may be an optional solution to develop various multi-functional platforms for disease diagnosis and corresponding clinical treatment.

Indentation Stiffness Measurement by an Optical Coherence Tomography-Based Air-Jet Indentation System Can Reflect Type I Collagen Abundance and Organisation in Diabetic Wounds

There is a lack of quantitative and non-invasive clinical biomechanical assessment tools for diabetic foot ulcers. Our previous study reported that the indentation stiffness measured by an optical coherence tomography-based air-jet indentation system in a non-contact and non-invasive manner may reflect the tensile properties of diabetic wounds. As the tensile properties are known to be contributed by type I collagen, this study was aimed to establish the correlations between the indentation stiffness, and type I collagen abundance and organisation, in order to further justify and characterise the in vivo indentation stiffness measurement in diabetic wounds. In a male streptozotocin-induced diabetic rat model, indentation stiffness, and type I collagen abundance and organisation of excisional wounds were quantified and examined using the optical coherence tomography-based air-jet indentation system and picrosirius red polarised light microscopy, respectively, on post-wounding days 3, 5, 7, 10, 14, and 21. The results showed significant negative correlations between indentation stiffness at the wound centre, and the collagen abundance and organisation. The correlations between the indentation stiffness, as well as collagen abundance and organisation of diabetic wounds suggest that the optical coherence tomography-based air-jet indentation system can potentially be used to quantitatively and non-invasively monitor diabetic wound healing in clinical settings, clinical research or preclinical research.

Injectable Desferrioxamine-Laden Silk Nanofiber Hydrogels for Accelerating Diabetic Wound Healing

Dysangiogenesis and chronic inflammation are two critical reasons for diabetic foot ulcers. Desferrioxamine (DFO) was used clinically in the treatment of diabetic foot ulcers by repeated injections because of its capacity to induce vascularization. Biocompatible carriers that release DFO slowly and facilitate healing simultaneously are preferable options to accelerate the healing of diabetic wounds. Here, DFO-laden silk nanofiber hydrogels that provided a sustained release of DFO for more than 40 days were used to treat diabetic wounds. The DFO-laden hydrogels stimulated the healing of diabetic wounds. In vitro cell studies revealed that the DFO-laden hydrogels modulated the migration and gene expression of endothelial cells, and they also tuned the inflammation behavior of macrophages. These results were confirmed in an in vivo diabetic wound model. The DFO-laden hydrogels alleviated dysangiogenesis and chronic inflammation in the diabetic wounds, resulting in a more rapid wound healing and increased collagen deposition. Both in vitro and in vivo studies suggested potential clinical applications of these DFO-laden hydrogels in the treatment of diabetic ulcers.

A single-center blinded randomized clinical trial to evaluate the anti-aging effects of a novel HSF™-based skin care formulation

BACKGROUND

Similar to chronic wounds, skin aging is characterized by dysfunction of key cellular regulatory pathways. The hypoxia-inducible factor-1 alpha (HIF-1α) pathway was linked to both conditions. Recent evidence suggests that modulating this pathway can rejuvenate aged fibroblasts and improve skin regeneration. Here, we describe the application of a novel HIF stimulating factor (HSF™)-based formulation for skin rejuvenation.

METHODS

Over a period of 6 weeks using a split-face study design, the effects on skin surface profile, skin moisture, and transepidermal water loss were determined in 32 female subjects (mean age 54, range 32-67 years) by Fast Optical in vivo Topometry of Human Skin (FOITS_HD ), Corneometer, and Tewameter measurements. In addition, a photo documentation was performed for assessment by an expert panel and a survey regarding subject satisfaction was conducted.

RESULTS

No negative skin reactions of dermatological relevance were documented for the test product. A significant reduction in skin roughness could be demonstrated. The clinical evaluation of the images using a validated method confirmed significant improvement of wrinkles, in particular of fine wrinkles, lip wrinkles, and crow's feet. A significant skin moisturizing effect was detected while skin barrier function was preserved. The HSF™-based skin care formulation resulted in a self-reported 94% satisfaction rate.

CONCLUSION

With no negative skin reactions and highly significant effects on skin roughness, wrinkles, and moisturization, the HSF™-based skin care formulation achieved very satisfying outcomes in this clinical trial. Given the favorable results, this approach represents a promising innovation in aesthetic and regenerative medicine.

Recipient-Site Preconditioning with Deferoxamine Increases Fat Graft Survival by Inducing VEGF and Neovascularization in a Rat Model

BACKGROUND

The authors hypothesize that ischemic preconditioning of the recipient site with deferoxamine will increase fat graft survival by enhancing angiogenesis in a rat model.

METHODS

Cell viability, tube formation, and mRNA expression were measured in human umbilical vein endothelial cells treated with deferoxamine. A total of 36 rats were then used for an in vivo study. A dose of 100 mg/kg of deferoxamine was injected subcutaneously into the rat scalp every other day for five treatments. On the day after the final injection, the scalp skin was harvested from half the animals to evaluate the effects of deferoxamine on the recipient site. In the remaining animals, inguinal fat tissue was transplanted to the scalp. Eight weeks after transplantation, the grafts were harvested to evaluate the effects of deferoxamine preconditioning on fat graft survival.

RESULTS

In human umbilical vein endothelial cells, treatment with a deferoxamine concentration higher than 400 μM decreased cell viability compared with the control (p = 0.002). Treatment with 100 and 200 μM deferoxamine increased endothelial tube formation (p = 0.001) and mRNA levels of angiogenesis-related factors (p = 0.02). Rat scalps treated with deferoxamine exhibited increased capillary neoformation (p = 0.001) and vascular endothelial growth factor protein expression (p = 0.024) compared with controls. Fat graft volume retention, capillary density (p < 0.001), and adipocyte viability (p < 0.001) in the grafted fat increased when the recipient site was preconditioned with deferoxamine.

CONCLUSION

This study demonstrated that recipient site preconditioning with deferoxamine increases fat graft survival by inducing vascular endothelial growth factor and neovascularization.

Diabetic Foot Ulcers: Current Advances in Antimicrobial Therapies and Emerging Treatments

Diabetic foot ulcers (DFUs) are very important diabetes-related lesions that can lead to serious physical consequences like amputations of limbs and equally severe social, psychological, and economic outcomes. It is reported that up to 25% of patients with diabetes develop a DFU in their lifetime, and more than half of them become infected. Therefore, it is essential to manage infection and ulcer recovery to prevent negatives outcomes. The available information plays a significant role in keeping both physicians and patients aware of the emerging therapies against DFUs. The purpose of this review is to compile the currently available approaches in the managing and treatment of DFUs, including molecular and regenerative medicine, antimicrobial and energy-based therapies, and the use of plant extracts, antimicrobial peptides, growth factors, ozone, devices, and nano-medicine, to offer an overview of the assessment of this condition.

The Role of Deferoxamine in Irradiated Breast Reconstruction: A Study of Oncologic Safety

BACKGROUND

Radiotherapy plays an essential role in the oncologic management of breast cancer. However, patients who undergo radiotherapy experience significantly more wound complications during the reconstructive process. Deferoxamine has immense potential to up-regulate angiogenesis and improve reconstructive outcomes. The purpose of this study was to determine the impact of deferoxamine on breast cancer cell proliferation in vitro, to delineate oncologic safety concerns regarding the use of deferoxamine as a regenerative therapeutic.

METHODS

The dose-dependent effect of radiation and deferoxamine on two triple-negative breast cancer cell lines (MDA-MB-231 and MDA-MB-468) was determined by means of MTS (percentage cell viability) and tumorsphere (sphere number) analysis. Radiation therapy and deferoxamine were delivered both individually and in combination, and all experiments were completed in triplicate. Intracellular iron, nuclear factor-κB localization, and apoptosis/necrosis assays were performed to delineate mechanism. Analysis of variance statistical analysis was performed using SPSS (p < 0.05).

RESULTS

For both cell lines, percentage viability and sphere number significantly decreased following exposure to 10 Gy of radiation. Surprisingly, the administration of 25 µM deferoxamine also significantly decreased each metric. The administration of deferoxamine (100 µM) in combination with radiation (10 Gy) resulted in significantly reduced percentage viability and sphere number compared with the administration of radiation alone. Deferoxamine treatment decreased intracellular iron, suppressed nuclear factor-κB activation, and induced apoptosis.

CONCLUSION

Radiation and deferoxamine significantly decrease breast cancer proliferation when delivered independently and in combination, suggesting deferoxamine may be safely used to facilitate improved reconstructive outcomes among triple-negative breast cancer survivors.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, V.

Bioinorganics and Wound Healing

Wound dressings and the healing enhancement (increasing healing speed and quality) are two components of wound care that lead to a proper healing. Wound care today consists mostly of providing an optimal environment by removing waste and necrotic tissues from a wound, preventing infections, and keeping the wounds adequately moist. This is however often not enough to re-establish the healing process in chronic wounds; with the local disruption of vascularization, the local environment is lacking oxygen, nutrients, and has a modified ionic and molecular concentration which limits the healing process. This disruption may affect cellular ionic pumps, energy production, chemotaxis, etc., and will affect the healing process. Biomaterials for wound healing range from simple absorbents to sophisticated bioactive delivery vehicles. Often placing a material in or on a wound can change multiple parameters such as pH, ionic concentration, and osmolarity, and it can be challenging to pinpoint key mechanism of action. This article reviews the literature of several inorganic ions and molecules and their potential effects on the different wound healing phases and their use in new wound dressings.

Lecithin-based deferoxamine nanoparticles accelerated cutaneous wound healing in diabetic rats

Nanoparticles have higher frequency of being exposed to cells or tissue, and are thus more likely to gain access into cytoplasm or nuclei to modulate molecular events due to significantly larger surface area to volume ratio. As a result, they present amplified response or even different physiochemical and biomedical properties from bigger particles. Deferoxamine accelerates wound healing in diabetic rats by increased neovascularization, reduced inflammation and improved maturation of wound. We investigated the wound healing potential of deferoxamine-nanoparticles in diabetic rats. Lecithin based nanoparticles of deferoxamine were prepared and characterized. The diabetic rats were divided into five Groups, of which Group I was treated with pluronic-gel f-127 (25%), Group II with deferoxamine 0.1% and Group III, IV and V were treated with deferoxamine-nanoparticles incorporated in pluronic-gel f-127 25% at 0.03% (0.01% deferoxamine), 0.1% (0.03% deferoxamine) and 0.3% (0.1% deferoxamine) w/v respectively. The wound closure was significantly accelerated in group V as compared to control groups. HIF-1α, VEGF, SDF-1α, TGF-β₁, and IL-10 protein levels were significantly higher in group V. The collagen deposition and neovascularization was greater in deferoxamine-nanoparticle treated rats. In contrast, TNF-α level was lowest in group V. In summary, the deferoxamine-nanoparticle formulation we developed, when applied topically on diabetic wounds results in faster wound healing as compared to simple deferoxamine formulation. This formulation may prove to be an effective therapy for treatment of diabetic wounds.

Therapeutic strategies for enhancing angiogenesis in wound healing

The enhancement of wound healing has been a goal of medical practitioners for thousands of years. The development of chronic, non-healing wounds is a persistent medical problem that drives patient morbidity and increases healthcare costs. A key aspect of many non-healing wounds is the reduced presence of vessel growth through the process of angiogenesis. This review surveys the creation of new treatments for healing cutaneous wounds through therapeutic angiogenesis. In particular, we discuss the challenges and advancement that have been made in delivering biologic, pharmaceutical and cell-based therapies as enhancers of wound vascularity and healing.

Exosomes Derived from Human Bone Marrow Mesenchymal Stem Cells Stimulated by Deferoxamine Accelerate Cutaneous Wound Healing by Promoting Angiogenesis

The exosomes are derived from mesenchymal stem cells (MSCs) and may be potentially used as an alternative for cell therapy, for treating diabetic wounds, and aid in angiogenesis. This study, aimed to investigate whether exosomes originated from bone marrow-derived MSCs (BMSCs) preconditioned by deferoxamine (DFO-Exos) exhibited superior proangiogenic property in wound repair and to explore the underlying mechanisms involved. Human umbilical vein endothelial cells (HUVECs) were used for assays involving cell proliferation, scratch wound healing, and tube formation. To test the effects in vivo, streptozotocin-induced diabetic rats were established. Two weeks after the procedure, histological analysis was used to measure wound-healing effects, and the neovascularization was evaluated as well. Our findings demonstrated that DFO-Exos activate the PI3K/AKT signaling pathway via miR-126 mediated PTEN downregulation to stimulate angiogenesis in vitro. This contributed to enhanced wound healing and angiogenesis in streptozotocin-induced diabetic rats in vivo. Our results suggest that, in cell-free therapies, exosomes derived from DFO preconditioned stem cells manifest increased proangiogenic ability.

Mechanistic insight into diabetic wounds: Pathogenesis, molecular targets and treatment strategies to pace wound healing

Wound management in diabetic patient is of an extreme clinical and social concern. The delayed and impaired healing makes it more critical for research focus. The research on impaired healing process is proceeding hastily evident by new therapeutic approaches other than conventional such as single growth factor, dual growth factor, skin substitutes, cytokine stimulators, cytokine inhibitors, matrix metalloproteinase inhibitors, gene and stem cell therapy, extracellular matrix and angiogenesis stimulators. Although numerous studies are available that support delayed wound healing in diabetes but detailed mechanistic insight including factors involved and their role still needs to be revealed. This review mainly focuses on the molecular cascades of cytokines (with growth factors) and erstwhile factors responsible for delayed wound healing, molecular targets and recent advancements in complete healing and its cure. Present article briefed recent pioneering information on possible molecular targets and treatment strategies including clinical trials to clinicians and researchers working in similar area.

Topical Deferoxamine Alleviates Skin Injury and Normalizes Atomic Force Microscopy Patterns Following Radiation in a Murine Breast Reconstruction Model

BACKGROUND

Breast cancer is most commonly managed with a combination of tumor ablation, radiation, and/or chemotherapy. Despite the oncologic benefit of these treatments, the detrimental effect of radiation on surrounding tissue challenges the attainment of ideal breast reconstruction outcomes. The purpose of this study was to determine the ability of topical deferoxamine (DFO) to reduce cutaneous ulceration and collagen disorganization following radiotherapy in a murine model of expander-based breast reconstruction.

METHODS

Female Sprague-Dawley rats (n = 15) were divided into 3 groups: control (expander), XRT (expander + radiation), and DFO (expander + radiation + deferoxamine [DFO]). Expanders were placed in a submusculocutaneous plane in the right upper back and ultimately filled to 15 mL. Radiation was administered via a fractionated dose of 28 Gy. Deferoxamine was delivered topically for 10 days following radiation. After a 20-day recovery period, skin ulceration and dermal type I collagen organization were analyzed.

RESULTS

Compared with control, the XRT group demonstrated a significant increase in skin ulceration (3.7% vs 43.3%, P = 0.00) and collagen fibril disorganization (26.3% vs 81.8%, P = 0.00). Compared with the XRT group, treatment with topical DFO resulted in a significant reduction in ulceration (43.3% vs 7.0%, P = 0.00) and fibril disorganization (81.8% vs 15.3%, P = 0.00). There were no statistical differences between the control and DFO groups in skin ulceration or collagen disorganization.

CONCLUSIONS

This study suggests topical DFO is capable of reducing skin ulceration and type I collagen fibril disorganization following radiotherapy. This novel application of DFO has potential to enhance expander-based breast reconstruction outcomes and improve quality of life for women suffering the devastating effects of breast cancer.

Skin Rejuvenation through HIF-1α Modulation

The constant intrinsic and extrinsic stress the skin is exposed to leads to significant impairments of the regenerative capacity of aging skin. Current skin rejuvenation approaches lack the ability to holistically support the biological processes that exhaust during aging skin degeneration, such as collagen production, cell migration and proliferation, and new vessel formation. Similar to chronic wounds, aged skin is characterized by dysfunction of key cellular regulatory pathways impairing regeneration. Recent evidence suggests that the same mechanisms hindering a physiologic healing response in chronic wounds are the basis of impaired tissue homeostasis in aged skin. Dysfunction of a main response-to-injury pathway, the hypoxia-inducible factor (HIF)-1α regulatory pathway, has been identified as pivotal both in chronic wounds and in aging skin degeneration. HIF-1α signaling is significantly involved in tissue homeostasis and neovascularization, resulting in the production of new collagen, elastin, and nourishing blood vessels. Modulating the functionality of this pathway has been demonstrated to significantly enhance tissue regeneration. In this review, we present an overview of the regenerative effects linked to the up-regulation of HIF-1α functionality, potentially resulting in skin rejuvenation on both the cellular level and the tissue level.

Effect of biogenic silver nanocubes on matrix metalloproteinases 2 and 9 expressions in hyperglycemic skin injury and its impact in early wound healing in streptozotocin-induced diabetic mice

Microbial contamination along with over expressions of matrix metalloproteinases 2 and 9 impairs wound healing in diabetic patients. Silver-based antimicrobial agents have been successfully used for treating non-healing chronic wounds associated with infection. However, topical application of silver-ion compounds impairs wound healing process. Thus, usage of biogenic silver nanoparticles appears as a new means to reduce the toxicity of silver compounds in the wound care system. Here, following our previous method, AgNPs was synthesized using the culture filtrate of Brevibacillus brevis KN8(2) then characterized by UV-visible spectrophotometry, TEM, SAED, XRD and DLS measurements. The antibacterial activity of AgNPs was evaluated against the most common wound infecting pathogens Pseudomonas aeruginosa and Staphylococcus aureus by well diffusion assay. Further, the wound healing efficacy of biogenic AgNPs was examined in streptozotocin-induced diabetic mice by measuring wound area closure, histopathology, mRNA and protein expressions of MMP-2, MMP-9. Our results demonstrates that besides antimicrobial activity, biogenic AgNPs decreased the mRNA and protein expression of MMP-2 and MMP-9 in wounded granulation tissues leads to early wound healing in diabetic mice. These findings revealed that biogenic AgNPs synthesized from B. brevis KN8(2) could be an effective therapeutic agent in the management of diabetic foot ulcer with/without infection.

The effect of earthworm extract on promoting skin wound healing

Chronic nonhealing wounds pose a significant challenge to healthcare system because of its tremendous utilization of resources and time to heal. It has a well-deserved reputation for reducing the quality of life for those affected and represent a substantial economic burden to the healthcare system overall. Earthworms are used as a traditional Chinese medicine, and have been applied pharmacologically and clinically since a long time in China. However, there is paucity in data regarding its wound healing effects. Therefore, we investigated the effect of earthworm extract (EE) on skin wound healing process. The obtained data showed that EE has healing effects on local wound of mice. It decreased the wound healing time and reduced the ill-effects of inflammation as determined by macroscopic, histopathologic, hematologic, and immunohistochemistry parameters. The potential mechanism could be accelerated hydroxyproline and transforming growth factor-β secretion—thus increasing the synthesis of collagen, promoting blood capillary, and fibroblast proliferation. It could accelerate the removal of necrotic tissue and foreign bodies by speeding up the generation of interleukin-6, white blood cells, and platelets. It thus enhances immunity, reduces the risk of infection, and promotes wound healing. All in all, the obtained data demonstrated that EE improves quality of healing and could be used as a propitious wound healing agent.

Effects of Selenium Supplementation on Gene Expression Levels of Inflammatory Cytokines and Vascular Endothelial Growth Factor in Patients with Gestational Diabetes

Selenium is known to exert multiple beneficial effects including anti-inflammatory actions. The aim of the study was to evaluate the effects of selenium supplementation on gene expression levels of inflammatory cytokines and vascular endothelial growth factor (VEGF) in women with gestational diabetes (GDM). This randomized double-blind, placebo-controlled trial was carried out among 40 subjects diagnosed with GDM aged 18-40 years old. Subjects were randomly allocated into two groups to receive either 200 μg/day selenium supplements (n = 20) or placebo (n = 20) for 6 weeks. Gene expression of inflammatory cytokines and VEGF were assessed in lymphocytes of GDM women with RT-PCR method. Results of RT-PCR indicated that after the 6-week intervention, compared with the placebo, selenium supplementation downregulated gene expression of tumor necrosis factor alpha (TNF-α) (P = 0.02) and transforming growth factor beta (TGF-β) (P = 0.01), and upregulated gene expression of VEGF (P = 0.03) in lymphocytes of patients with GDM. There was no statistically significant change following supplementation with selenium on gene expression of interleukin (IL)-1β and IL-8 in lymphocytes of subjects with GDM. Selenium supplementation for 6 weeks in women with GDM significantly decreased gene expression of TNF-α and TGF-β, and significantly increased gene expression of VEGF, but did not affect gene expression of IL-1β and IL-8. Clinical trial registration number http://www.irct.ir : IRCT201612045623N95.

Wound healing properties of Copaifera paupera in diabetic mice

Copaifera oleoresin is one of the most used natural products in popular medicine all over the world. Among other effects (i.e., anti-inflammatory, antinociceptive, microbicidal) one of the most well-known is its wound healing capacity. However, the mechanism by which the oleoresin presents its effect is still not clear. In this study, our aim was to evaluate the wound healing capacity of oleoresin obtained from Copaifera paupera, its mechanism of action and identify its major components. For these purposes, diabetic Swiss Webster mice were topically treated with oleoresin (100, 150 or 200 mg/kg) for 14 consecutive days after an excision was performed in the back of the mice. Cytokines, wound retraction and histological evaluation were conducted at 3, 7 and 10 days (for cytokines); 0, 3, 7, 10 and 14 days (for wound retraction); and 7 and 14 days (for histological evaluation). Our data indicate that oleoresin significantly reduced production of MCP-1 and TNF-α at days 7 and 10 post-excision and increased IL-10 production at both days. All treatments demonstrated an effect similar or higher to that in collagenase-treated mice. Histological evaluations demonstrated that higher dose treatment resulted in better resolution and closure of the wound and higher levels of collagen deposition and indexes of re-epithelialization even when compared with the collagenase-treated group. The treatment with oleoresin from Copaifera paupera demonstrated that it is even better than an ointment routinely used for improvement of wound healing, suggesting this oleoresin as an option for use in diabetic patients.

Hydroethanolic Extract of Strychnos pseudoquina Accelerates Skin Wound Healing by Modulating the Oxidative Status and Microstructural Reorganization of Scar Tissue in Experimental Type I Diabetes

The effect of topical application of ointment based on Strychnos pseudoquina hydroethanolic extract in the cutaneous wounds healing in diabetic rats was evaluated. Samples of S. pseudoquina were submitted to phytochemical prospection and in vitro antioxidant assay. Thirty Wistar rats were divided into 5 groups: Sal-wounds treated with 0.9% saline solution; VH-wounds treated with 0.6 g of lanolin cream (vehicle); SS-wounds treated with silver sulfadiazine cream (10 mg/g); ES5- and ES10-wounds treated with an ointment of S. pseudoquina extract, 5% and 10%, respectively. Fragments of wounds were removed for histological and biochemical analysis every 7 days during 21 days. ES showed equivalent levels per gram of extract of total phenols and flavonoids equal to 122.04 mg for TAE and 0.60 mg for RE. The chlorogenic acid was one of the major constituents. S. pseudoquina extract presented high antioxidant potential in vitro. ES5 and ES10 showed higher wound healing rate and higher amount of cells, blood vessels, and type III and I collagen. The oxidative stress markers were lower in the ES5 and ES10 groups, while the antioxidants enzymes levels were higher. Ointment based on S. pseudoquina extract promotes a fast and efficient cutaneous repair in diabetic rats.

Effect of a high-fat diet and alcohol on cutaneous repair: A systematic review of murine experimental models

BACKGROUND AND PURPOSE

Chronic alcohol intake associated with an inappropriate diet can cause lesions in multiple organs and tissues and complicate the tissue repair process. In a systematic review, we analyzed the relevance of alcohol and high fat consumption to cutaneous and repair, compared the main methodologies used and the most important parameters tested. Preclinical investigations with murine models were assessed to analyze whether the current evidence support clinical trials.

METHODS

The studies were selected from MEDLINE/PubMed and Scopus databases, according to Fig 1. All 15 identified articles had their data extracted. The reporting bias was investigated according to the ARRIVE (Animal Research: Reporting of in Vivo Experiments) strategy.

RESULTS

In general, animals offered a high-fat diet and alcohol showed decreased cutaneous wound closure, delayed skin contraction, chronic inflammation and incomplete re-epithelialization.

CONCLUSION

In further studies, standardized experimental design is needed to establish comparable study groups and advance the overall knowledge background, facilitating data translatability from animal models to human clinical conditions.

Negative pressure wound therapy inhibits inflammation and upregulates activating transcription factor-3 and downregulates nuclear factor-κB in diabetic patients with foot ulcerations

BACKGROUND

Negative pressure wound therapy (NPWT) is one of the most important treatments for diabetic foot, but the underlying mechanisms of its benefits still remain elusive. This study aims to evaluate the inflammatory signals involved in the effects of negative pressure therapy on diabetic foot ulcers.

METHODS

We enrolled 22 patients with diabetic foot ulceration, 11 treated with NPWT and the other 11 treated with traditional debridement. All patients were treated and observed for 1 week. Granulation tissues were harvested and analyzed in both groups, and then were histologically and immunohistochemically analyzed. Enzyme-linked immunosorbent assay, Western blot analysis, and real-time PCR were performed to evaluate the expression of interleukin-6 (IL-6), tumor necrosis factor α (TNF-α), inducible nitric oxide synthase (iNOS), nuclear factor-κB (NF-κB) p65, I_k B-α, and activating transcription factor-3 (ATF-3).

RESULTS

After 7 days of treatment, NPWT could obviously promote diabetic wound healing because of the mild inflammation and the dense cell-deposited matrix. Meanwhile, NPWT significantly decreased the expression of TNF-α, IL-6, and iNOS (all P < .05). The result of Western blotting and real-time PCR indicated that NPWT obviously decreased the level of I_k B-α and NF-κB p65, and increased the level of ATF-3 (all P < .05).

CONCLUSION

NPWT exerts an anti-inflammatory effect, possibly through the suppression of proinflammatory enzymes and cytokines resulting from I_k B-α inhibition and ATF-3 activation, which may prevent the activation of the NF-κB pathway in human diabetic foot wounds.

In vitro assessment of deferoxamine on mesenchymal stromal cells from tumor and bone marrow

Deferoxamine (DFO), an iron chelator, is commonly used to remove excess iron from the body. DFO has also been demonstrated to have anti-tumor effect. However, there is no available report on the effect of deferoxamine on mesenchymal stromal cells (MSCs). In this study, we first isolated tumor-associated MSCs (TAMSCs) from EG-7 tumors, which were positive for CD29, CD44, CD73, CD90 and CD105. Ex vivo cultured stem cells derived from tumor and bone marrow compartment were exposed to DFO. We demonstrated that DFO had growth-arresting and apoptosis-inducing effect on TAMSCs and bone marrow MSCs (BMMSCs). DFO also influenced the expression pattern of adhesion molecule VCAM-1 on both TAMSCs and BMMSCs. Notwithstanding its widespread use, our results here warrants caution in the application of DFO, and also highlights the need for careful evaluation of the bone marrow compartment in patients receiving DFO treatment.

Yamin B, Al-Obaidi MMJ, Batran RA. In vivo Assessment of Antioxidant and Wound Healing Improvement of a New Schiff Base Derived Co (II) Complex in Rats

Co (II) complex (CMLA) was investigated to evaluate the rate of wound healing in rats. Animals were placed into four groups: gum acacia, Intrasite gel, 10 and 20 mg/ml of CMLA. Wounds were made on the dorsal neck area, then treated with Intrasite gel or CMLA; both of these treatments led to faster healing than with gum acacia. Histology of the wounds dressed with CMLA or Intrasite gel displayed a smaller scar width, required less time to heal and showed more collagen staining and fewer inflammatory cells in comparison to wounds dressed with the vehicle. Immunohistochemistry for Hsp70 and TGF-β showed greater staining intensity in the treated groups compared to the vehicle group. Bax staining was less intense in treated groups compared to the vehicle group, suggesting that CMLA and Intrasite gel provoked apoptosis, responsible for the development of granulation tissue into a scar. CD31 protein analysis showed that the treated groups enhanced angiogenesis and increased vascularization compared to the control group. Furthermore, a significant increase in the levels of GPx and SOD and a decrease in MDA were also observed in the treated groups. This results suggest that CMLA is a potentially promising agent for the wounds treatment.

Exosomes Derived from Human Endothelial Progenitor Cells Accelerate Cutaneous Wound Healing by Promoting Angiogenesis Through Erk1/2 Signaling

Chronic skin wounds represent one of the most common and disabling complications of diabetes. Endothelial progenitor cells (EPCs) are precursors of endothelial cells and can enhance diabetic wound repair by facilitating neovascularization. Recent studies indicate that the transplanted cells exert therapeutic effects primarily via a paracrine mechanism and exosomes are an important paracrine factor that can be directly used as therapeutic agents for regenerative medicine. However, application of exosomes in diabetic wound repair has been rarely reported. In this study, we demonstrated that the exosomes derived from human umbilical cord blood-derived EPCs (EPC-Exos) possessed robust pro-angiogenic and wound healing effects in streptozotocin-induced diabetic rats. By using a series of in vitro functional assays, we found that EPC-Exos could be incorporated into endothelial cells and significantly enhance endothelial cells' proliferation, migration, and angiogenic tubule formation. Moreover, microarray analyses indicated that exosomes treatment markedly altered the expression of a class of genes involved in Erk1/2 signaling pathway. It was further confirmed with functional study that this signaling process was the critical mediator during the exosomes-induced angiogenic responses of endothelial cells. Therefore, EPC-Exos are able to stimulate angiogenic activities of endothelial cells by activating Erk1/2 signaling, which finally facilitates cutaneous wound repair and regeneration.

Negative pressure wound therapy promotes vessel destabilization and maturation at various stages of wound healing and thus influences wound prognosis

Negative pressure wound therapy (NPWT) has been observed to accelerate the wound healing process in humans through promoting angiogenesis. However, the potential biological effect and relevant molecular mechanisms, including microvessel destabilization, regression and endothelial cell proliferation in the early stage (1–3 days), and the neovascular stabilization and maturation in the later stage (7–15 days), have yet to be fully elucidated. The current study aimed to research the potential effect of NPWT on angiogenesis and vessel maturation, and investigate relevant association between mature microvessels and wound prognosis, as well as the regulatory mechanisms in human wound healing. Patients in the present study (n=48) were treated with NPWT or a petrolatum gauze, and relevant growth factors and vessel changes were detected using various experimental methods. NPWT increased the expression levels of angiogenin-2 (Ang-2), and decreased the expression levels of Ang-1 and ratios of Ang-1/Ang-2 in the initial stages of wound healing. However, in the latter stages of wound healing, NPWT increased the expression levels of Ang-1 and ratios of Ang-1/Ang-2, as well as the phosphorylation level of tyrosine kinase receptor-2. Consequently, microvessel pericyte coverage was gradually elevated, and the basement membrane was gradually supplied with new blood at the later stage of wound healing. In conclusion, NPWT may preferentially stimulate microvessel destabilization and regression in the early stage of wound healing, and as a consequence, increase angiogenesis. Subsequently, in the later stage of wound healing, NPWT may preferentially promote microvessel stabilization, thereby promoting microvessel maturation in human wounds through the angiogenin/tyrosine kinase receptor-2 signaling pathway. The results of the present study results demonstrated that NPWT was able to accelerate wound healing speed, and thus influence wound prognosis, as a result of an abundance of mature microvessels in human wounds.

Bilirubin modulated cytokines, growth factors and angiogenesis to improve cutaneous wound healing process in diabetic rats

Bilirubin has shown cutaneous wound healing potential in some preliminary studies. Here we hypothesize that bilirubin facilitates wound healing in diabetic rats by modulating important healing factors/candidates and antioxidant parameters in a time-dependent manner. Diabetes was induced in male Wistar rats by streptozotocin. In all diabetic rats wounds were created under pentobarbitone anesthesia. All the rats were divided into two groups, of which one (control) was treated with ointment base and other with bilirubin ointment (0.3%). Wound closer measurement and tissue collection were done on days 3, 7, 14 and 19 post-wounding. The relative expressions of hypoxia inducible factor-1 alpha (HIF-1α), vascular endothelial growth factor (VEGF), stromal cell-derived factor-1 alpha (SDF-1α), transforming growth factor- beta1 (TGF-β1()), tumor necrosis factor-α (TNF-α) and interlukin-10 (IL-10) mRNA and proteins and the mRNA of interlukin-1 beta (IL-1β) and matrix metalloprteinase-9 (MMP-9) were determined in the wound tissues. CD-31 staining and collagen content were evaluated by immunohistochemistry and picrosirius red staining, respectively. Histopathological changes were assessed by H&E staining. The per cent wound closer was significantly higher from day 7 onwards in bilirubin-treated rats. HIF-1α, VEGF, SDF-1α, TGF-β1, IL-10 mRNA and protein levels were significantly higher on days 3, 7 and 14 in bilirubin-treated rats. The mRNA expression and protein level of TNF-α and the mRNA of IL-1β and MMP-9 were progressively and markedly reduced in bilirubin-treated rats. The collagen deposition and formation of blood vessels were greater in bilirubin-treated rats. Bilirubin markedly facilitated cutaneous wound healing in diabetic rats by modulating growth factors, cytokines, neovasculogenesis and collagen contents to the wound site. Topical application of bilirubin ointment might be of great use in cutaneous wound healing in diabetic patients.