Extracellular superoxide dismutase deficiency impairs wound healing in advanced age by reducing neovascularization and fibroblast function

Multifunctional nanocomposite hydrogels: an effective approach to promote diabetic wound healing

Diabetes, a metabolic disease that is becoming increasingly severe globally, presents a significant challenge in the medical field. Diabetic wounds are characterized by their chronicity, difficulty healing, and complex microenvironment that harbors multiple adverse factors, including elevated hyperglycemia, persistent inflammation, susceptibility to infections, and oxidative stress, all of which contribute to the impaired healing process. Nanocomposite hydrogels, as materials with unique physicochemical properties and biocompatibility, have gained growing attention in recent years for their potential applications in diabetic wound healing. These hydrogels provide a moist healing environment for wounds and regulate cellular behavior and signaling pathways, promoting wound repair and healing. By introducing specific functional groups and nanoparticles, nanocomposite hydrogels can respond to pathological features of wounds, enabling adaptive drug release. Owing to their diverse bioactive functions, nanocomposite hydrogels are powerful tools for the treatment of diabetic wounds. Thus, this article provides an overview of recent progress in the use of nanocomposite hydrogels for diabetic wound healing.

Low-temperature cold plasma promotes wound healing by inhibiting skin inflammation and improving skin microbiome

Wound healing includes four consecutive and overlapping stages of hemostasis, inflammation, proliferation, and remodeling. Factors such as aging, infection, and chronic diseases can lead to chronic wounds and delayed healing. Low-temperature cold plasma (LTCP) is an emerging physical therapy for wound healing, characterized by its safety, environmental friendliness, and ease of operation. This study utilized a self-developed LTCP device to investigate its biological effects and mechanisms on wound healing in adult and elderly mice. Histopathological studies found that LTCP significantly accelerated the healing rate of skin wounds in mice, with particularly pronounced effects in elderly mice. LTCP can markedly inhibit the expression of pro-inflammatory cytokines (TNF-α, IL-6, IL-1β) and senescence-associated secretory phenotype factors (MMP-3, MMP-9), while significantly increasing the expression of tissue repair-related factors, such as VEGF, bFGF, TGF-β, COL-I, and α-SMA. It also regulated the expression of genes related to cell proliferation and migration (Aqp5, Spint1), inflammation response (Nlrp3, Icam1), and angiogenesis (Ptx3, Thbs1), promoting cell proliferation and inhibit apoptosis. Furthermore, LTCP treatment reduced the relative abundance of harmful bacteria such as Delftia, Stenotrophomonas, Enterococcus, and Enterobacter in skin wounds, while increasing the relative abundance of beneficial bacteria such as Muribaculaceae, Acinetobacter, Lachnospiraceae NK4A136_group, and un_f__Lachnospiraceae, thereby improving the microbial community structure of skin wounds. These research findings are of significant implications for understanding the mechanism of skin wound healing, as well as for the treatment and clinical applications of skin wounds, especially aging skin.

Mammalian copper homeostasis: physiological roles and molecular mechanisms

In the past decade, evidence for the numerous roles of copper (Cu) in mammalian physiology has grown exponentially. The discoveries of Cu involvement in cell signaling, autophagy, cell motility, differentiation, and regulated cell death (cuproptosis) have markedly extended the list of already known functions of Cu, such as a cofactor of essential metabolic enzymes, a protein structural component, and a regulator of protein trafficking. Novel and unexpected functions of Cu transporting proteins and enzymes have been identified, and new disorders of Cu homeostasis have been described. Significant progress has been made in the mechanistic studies of two classic disorders of Cu metabolism, Menkes disease and Wilson's disease, which paved the way for novel approaches to their treatment. The discovery of cuproptosis and the role of Cu in cell metastatic growth have markedly increased interest in targeting Cu homeostatic pathways to treat cancer. In this review, we summarize the established concepts in the field of mammalian Cu physiology and discuss how new discoveries of the past decade expand and modify these concepts. The roles of Cu in brain metabolism and in cell functional speciation and a recently discovered regulated cell death have attracted significant attention and are highlighted in this review.

Preclinical determination of wound-healing activity of halibut oil cream in rat model of burn wound

This study investigated the effects of halibut oil cream, containing omega-3 fatty acids, vitamins A and D, and hydroxyproline, on burn wound healing in rats. Acute dermal toxicity tests confirmed its nontoxicity. Wistar rats were divided into five groups: a control, a positive control treated with silver sulfadiazine 1% (SSD), and three groups treated with 3%, 9%, and 27% halibut oil cream Formulation (HBOF). The SSD and HBOF groups showed significant healing improvements compared to the control. Histopathological analysis indicated increased collagen production in the HBOF groups, suggesting halibut oil cream's potential as a topical treatment for burn wounds.

Chitosan-Electrospun Fibers Encapsulating Norfloxacin: The Impact on the Biochemical, Oxidative and Immunological Profile in a Rats Burn Model

This study investigates the impact of chitosan-based nanofibers on burn wound healing in a rat model. Two formulations of chitosan nanofibers were prepared through electrospinning. The formulations were then incorporated with different amounts of norfloxacin and underwent surface modifications with 2-formylphenylboronic acid. The burn model was applied to Wistar male rats by the contact method, using a heated steel rod attached to a thermocouple. The effectiveness of the nanofibers was tested against a negative control group and a standard commercial dressing (Atrauman Ag) on the described model and evaluated by wound diameter, histological analysis and biochemical profiling of systemic inflammatory markers. The results showed that chitosan-based dressings significantly accelerated burn healing compared to the control treatments. The high-concentration norfloxacin-infused chitosan coated with 2-formylphenylboronic acid' groups exhibited significant improvements in wound closure and reduced inflammation compared to the other groups; antioxidant enzymes SOD and GPx expression was significantly higher, p < 0.05, whereas pro-oxidative markers such as cortisol were lower (p < 0.05). Macroscopically, the wound area itself was significantly diminished in the chitosan-treated groups (p < 0.05). Furthermore, a histological evaluation indicated enhanced epithelialization and granulation tissue formation within the experiment time frame, while the biochemical panel revealed lower levels of inflammatory cytokines and lower leukocyte counts in the treated groups. These findings highlight the potential of the studied chitosan nanofibers as novel nanosystems for next-generation wound therapies, as well as the clinical utility of the novel chitosan fibers obtained by electrospinning technique.

Cellular and molecular roles of reactive oxygen species in wound healing

Wound healing is a highly coordinated spatiotemporal sequence of events involving several cell types and tissues. The process of wound healing requires strict regulation, and its disruption can lead to the formation of chronic wounds, which can have a significant impact on an individual's health as well as on worldwide healthcare expenditure. One essential aspect within the cellular and molecular regulation of wound healing pathogenesis is that of reactive oxygen species (ROS) and oxidative stress. Wounding significantly elevates levels of ROS, and an array of various reactive species are involved in modulating the wound healing process, such as through antimicrobial activities and signal transduction. However, as in many pathologies, ROS play an antagonistic pleiotropic role in wound healing, and can be a pathogenic factor in the formation of chronic wounds. Whilst advances in targeting ROS and oxidative stress have led to the development of novel pre-clinical therapeutic methods, due to the complex nature of ROS in wound healing, gaps in knowledge remain concerning the specific cellular and molecular functions of ROS in wound healing. In this review, we highlight current knowledge of these functions, and discuss the potential future direction of new studies, and how these pathways may be targeted in future pre-clinical studies.

Boron in wound healing: a comprehensive investigation of its diverse mechanisms

Chronic wounds present a significant clinical challenge due to their prolonged healing time and susceptibility to infection. Boron, a trace element with diverse biological functions, has emerged as a promising therapeutic agent in wound healing. This review article comprehensively investigates the mechanisms underlying the beneficial effects of boron compounds in wound healing. Boron exerts its healing properties through multiple pathways, including anti-inflammatory, antimicrobial, antioxidant, and pro-proliferative effects. Inflammation is a crucial component of the wound-healing process, and boron has been shown to modulate inflammatory responses by inhibiting pro-inflammatory cytokines and promoting the resolution of inflammation. Furthermore, boron exhibits antimicrobial activity against a wide range of pathogens commonly associated with chronic wounds, thereby reducing the risk of infection and promoting wound closure. The antioxidant properties of boron help protect cells from oxidative stress, a common feature of chronic wounds that can impair healing. Additionally, boron stimulates cell proliferation and migration, as well as essential tissue regeneration and wound closure processes. Overall, this review highlights the potential of boron as a novel therapeutic approach for treating chronic wounds, offering insights into its diverse mechanisms of action and clinical implications.

GelMA loaded with exosomes from human minor salivary gland organoids enhances wound healing by inducing macrophage polarization

Non-healing skin wounds pose significant clinical challenges, with biologic products like exosomes showing promise for wound healing. Saliva and saliva-derived exosomes, known to accelerate wound repair, yet their extraction is difficult due to the complex environment of oral cavity. In this study, as a viable alternative, we established human minor salivary gland organoids (hMSG-ORG) to produce exosomes (MsOrg-Exo). In vitro, MsOrg-Exo significantly enhanced cell proliferation, migration, and angiogenesis. When incorporated into a GelMA-based controlled-release system, MsOrg-Exo demonstrated controlled release, effectively improving wound closure, collagen synthesis, angiogenesis, and cellular proliferation in a murine skin wound model. Further molecular analyses revealed that MsOrg-Exo promotes proliferation, angiogenesis and the secretion of growth factors in wound sites. Proteomic profiling showed that MsOrg-Exo's protein composition is similar to human saliva and enriched in proteins essential for wound repair, immune modulation, and coagulation. Additionally, MsOrg-Exo was found to modulate macrophage polarization, inducing a shift towards M1 and M2 phenotypes in vitro within 48 h and predominantly towards the M2 phenotype in vivo after 15 days. In conclusion, our study successfully extracted MsOrg-Exo from hMSG-ORGs, confirmed the effectiveness of the controlled-release system combining MsOrg-Exo with GelMA in promoting skin wound healing, and explored the potential role of macrophages in this action.

Highly Active Frozen Nanovesicles Microneedles for Senile Wound Healing via Antibacteria, Immunotherapy, and Skin Regeneration

Senile wound healing risks a variety of health complications and makes both economic and psychological burdens on patients greatly. Poor activity of aged dermal fibroblasts (A-FBs) and local disordered immunoreaction in the deep dermis contribute to delayed wound healing. Therefore, the locally complex microenvironment in deep requires additional processing. Herein, a novel double-layer hyaluronic acid methacrylate (HAMA)/polyvinyl alcohol (PVA) microneedle patch (MNP) coated by young fibroblast-derived exosomes (Y-EXOs) (Y-EXOs@HAMA/PVA MNP) is presented for deep drug delivery, aged wound healing and immunoregulation. A spraying and freeze-drying method is applied for keeping the bioactivity of the nanovesicles. An ideal loading of Y-EXOs and enhanced strength for penetration have realized after circulation for times. The Y-EXOs@HAMA/PVA MNP shows an excellent influence on delayed wound healing of aged skin with active A-FBs, more deposition of collagen and less production of IL-17A compared with application of aged fibroblast-derived exosomes (A-EXOs). Moreover, the content microRNAs in Y-EXOs and A-EXOs are sequenced for further study. This study initiatively demonstrates that Y-EXOs have effective function on both anti-aging and anti-inflammation and Y-EXOs@HAMA/PVA MNP is expected as a novel strategy for deep drug delivery for promoting hard wound healing in aged skin in future clinical application.

Mesoporous chitosan nanofibers loaded with norfloxacin and coated with phenylboronic acid perform as bioabsorbable active dressings to accelerate the healing of burn wounds

The paper reports new chitosan-based nanofibers, designed to address the healing of burn wounds. To this aim, mesoporous chitosan fiber mats were prepared by electrospinning using poly(ethylene oxide) as sacrificial additive, followed by loading with norfloxacin and coating with an antifungal agent via dynamic imine bonds. Dynamic vapor sorption experiment proved intra-fiber mesopores around 2.7 nm, and UV-vis, FTIR, and NMR spectroscopy confirmed the norfloxacin embedding and the imination reaction. SEM, AFM and POM techniques displayed semicrystalline nanofibers with average diameter around 170 nm entangled into a non-woven mat. Their mesoporous nature favored a rapid adsorption of fluids up to 17 g/g, and a biodegradation rate fitting the wound healing rate, i.e. up to 30 % mass loss in media of pH characteristic to wound exudate and total degradation in that characteristic to normal dermis. The composite fibers released the NFX and 2FPBA in a controlled manner, and showed antimicrobial activity against gram positive, gram negative and fungal strains. They had no cytotoxic effect on normal human dermal fibroblasts, and showed biocompatibility on experimental rats. The investigation of wound healing ability on second/third-degree burn model in rats revealed wound closure and total restoration of the fully functional dermis and epidermis.

Role of Enzymic Antioxidants in Mediating Oxidative Stress and Contrasting Wound Healing Capabilities in Oral Mucosal/Skin Fibroblasts and Tissues

Unlike skin, oral mucosal wounds are characterized by rapid healing and minimal scarring, attributable to the "enhanced" healing properties of oral mucosal fibroblasts (OMFs). As oxidative stress is increasingly implicated in regulating wound healing outcomes, this study compared oxidative stress biomarker and enzymic antioxidant profiles between patient-matched oral mucosal/skin tissues and OMFs/skin fibroblasts (SFs) to determine whether superior oral mucosal antioxidant capabilities and reduced oxidative stress contributed to these preferential healing properties. Oral mucosa and skin exhibited similar patterns of oxidative protein damage and lipid peroxidation, localized within the lamina propria/dermis and oral/skin epithelia, respectively. SOD1, SOD2, SOD3 and catalase were primarily localized within epithelial tissues overall. However, SOD3 was also widespread within the lamina propria localized to OMFs, vasculature and the extracellular matrix. OMFs were further identified as being more resistant to reactive oxygen species (ROS) generation and oxidative DNA/protein damage than SFs. Despite histological evaluation suggesting that oral mucosa possessed higher SOD3 expression, this was not fully substantiated for all OMFs examined due to inter-patient donor variability. Such findings suggest that enzymic antioxidants have limited roles in mediating privileged wound healing responses in OMFs, implying that other non-enzymic antioxidants could be involved in protecting OMFs from oxidative stress overall.

Effect of cannabis smoke condensate on human nasal epithelial cell adhesion, growth, and migration

OBJECTIVE

When inhaled, cannabis smoke interacts with airway tissues, including the nasal mucosa, which may lead to nasal pathologies. We examined the effect of cannabis smoke condensate (CSC) on nasal epithelial cell and tissue behaviors.

METHODS

Human nasal epithelial cells were exposed or not to CSC at different concentrations (1, 5, 10, and 20 %) and for different durations. Cell adhesion and viability were assessed, as well as post-wound cell migration and lactate dehydrogenase (LDH) release.

RESULTS

The nasal epithelial cells showed a larger cell size and a faint nucleus following exposure to CSC, compared to that observed in that control. This was supported by fewer adherent cells present after exposure for either 1 or 24 h to 5, 15, and 20 % CSC. CSC also had a significant toxic effect by reducing cell viability after both 1 and 24 h of exposure. This toxic effect was significant even at a low concentration (1 %) of CSC. The effects on nasal epithelial cell viability were confirmed by the decrease in cell migration. After the scratch and subsequent exposure to CSC for either 6 or 24 h, a complete inhibition of nasal epithelial cell migration was observed, compared to that found in the controls. CSC was toxic to the nasal epithelial cells, as the level of LDH significantly increased following cell exposure all CSC concentrations.

CONCLUSION

Cannabis smoke condensate had a negative effect on several nasal epithelial cell behaviors. These findings indicate that cannabis smoke could be a threat to nasal tissues and ultimately lead to nasal and sinus disorders.

Colonizing microbiota is associated with clinical outcomes in diabetic wound healing

With the development of society and the improvement of life quality, more than 500 million people are affected by diabetes. More than 10 % of people with diabetes will suffer from diabetic wounds, and 80 % of diabetic wounds will reoccur, so the development of new diabetic wound treatments is of great importance. The development of skin microbe research technology has gradually drawn people's attention to the complex relationship between microbes and diabetic wounds. Many studies have shown that skin microbes are associated with the outcome of diabetic wounds and can even be used as one of the indicators of wound prognosis. Skin microbes have also been found to have the potential to treat diabetic wounds. The wound colonization of different bacteria can exert opposing therapeutic effects. It is necessary to fully understand the skin microbes in diabetic wounds, which can provide valuable guidance for clinical diabetic wound treatment.

Sustained activation of NLRP3 inflammasome contributes to delayed wound healing in aged mice

The cutaneous wounds in the elderly heal poorly, resulting in medical and economic burdens posed by defect repairing. Age-related delayed wound healing is associated with persistent inflammation and insufficient ECM deposition. The NLRP3 inflammasome has been proven to be a critical regulator of age-related inflammatory diseases, as well as impaired wound healing. Here, we create a 6 mm full-thickness cutaneous wound on the back of young and aged mice. Compared with young mice, aged counterparts display a retardation in wound healing, accompanied by increased activation of NLRP3 inflammasome. The application of the NLRP3 inhibitor (MCC950) ameliorates wound healing in aged mice. MCC950 inhibits sustained inflammation and reduces pyroptotic cell death in fibroblasts by blocking the abnormal activation of the NLRP3 inflammasome. Our findings illuminate that the NLRP3 inflammasome is a previously unrecognized regulator of aged wound healing and may be a potential target for the therapeutic strategy of delayed wound healing with aging.

Construction of heparin-based hydrogel incorporated with Cu5.4O ultrasmall nanozymes for wound healing and inflammation inhibition

Excessive production of inflammatory chemokines and reactive oxygen species (ROS) can cause a feedback cycle of inflammation response that has a negative effect on cutaneous wound healing. The use of wound-dressing materials that simultaneously absorb chemokines and scavenge ROS constitutes a novel 'weeding and uprooting' treatment strategy for inflammatory conditions. In the present study, a composite hydrogel comprising an amine-functionalized star-shaped polyethylene glycol (starPEG) and heparin for chemokine sequestration as well as Cu5.4O ultrasmall nanozymes for ROS scavenging (Cu5.4O@Hep-PEG) was developed. The material effectively adsorbs the inflammatory chemokines monocyte chemoattractant protein-1 and interleukin-8, decreasing the migratory activity of macrophages and neutrophils. Furthermore, it scavenges the ROS in wound fluids to mitigate oxidative stress, and the sustained release of Cu5.4O promotes angiogenesis. In acute wounds and impaired-healing wounds (diabetic wounds), Cu5.4O@Hep-PEG hydrogels outperform the standard-of-care product Promogram® in terms of inflammation reduction, increased epidermis regeneration, vascularization, and wound closure.

Role of Melatonin in Angiotensin and Aging

The cellular utilization of oxygen leads to the generation of free radicals in organisms. The accumulation of these free radicals contributes significantly to aging and several age-related diseases. Angiotensin II can contribute to DNA damage through oxidative stress by activating the NAD(P)H oxidase pathway, which in turn results in the production of reactive oxygen species. This radical oxygen-containing molecule has been linked to aging and several age-related disorders, including renal damage. Considering the role of angiotensin in aging, melatonin might relieve angiotensin-II-induced stress by enhancing the mitochondrial calcium uptake 1 pathway, which is crucial in preventing the mitochondrial calcium overload that may trigger increased production of reactive oxygen species and oxidative stress. This review highlights the role and importance of melatonin together with angiotensin in aging and age-related diseases.

Effects of advanced glycation end products on neutrophil migration and aggregation in diabetic wounds

Increased accumulation of advanced glycation end products (AGEs) in diabetic skin is closely related to delayed wound healing. Studies have shown that the concentration of AGEs is elevated in the skin tissues and not subcutaneous tissues in refractory diabetic wounds, which suggests there may be a causal relationship between the two. In the present study, in vitro experiments revealed that AGEs activated neutrophils, and the migratory and adhesive functions of neutrophils decreased once AGE levels reached a certain threshold. Different levels of AGE expression differentially affected the function of neutrophils. Messenger RNA (mRNA) sequencing analysis combined with real-time polymerase chain reaction (PCR) showed that poliovirus receptor (PVR/CD155) and CTNND1, which play a role in migration- and adhesion-related signaling pathways, were decreased following AGE stimulation. Consequently, neutrophils cannot effectively stimulate the formation of the inflammatory belt needed to remove necrotic tissues and defend against foreign microorganisms within diabetic chronic wounds. In addition, this phenomenon may be related to the differential accumulation of AGEs in different layers of the skin.

It's all about the spaces between cells: role of extracellular matrix in liver fibrosis

Liver fibrosis is one of the leading complications of a variety of chronic liver disorders, including the nonalcoholic fatty liver disease, nonalcoholic steatohepatitis, liver cirrhosis and liver failure. The progression of liver fibrosis is driven by chronic inflammation, which activates the secretory fibroblasts to the myofibroblast phenotype. These specialized liver cells are called as hepatic stellate cells (HSCs). The excessive extracellular matrix (ECM) secretion creates a large number of complications. Fibrosis is the result of imbalance between the matrix synthesizing and matrix degrading factors. The major ECM proteins include the matrix metalloproteinases (MMPs), tissue inhibitor of metalloproteinases (TIMPs), lysyl oxidases (LOX), lysyl oxidase-like (LOXLs) enzymes, tenascins and others. These ECM proteins present novel avenues for the therapeutics of liver fibrosis. The current review highlights the major role played by these critical matrix proteins in liver fibrosis. Further, some of the targeted formulations used against these proteins are discussed and suggestions are provided to select the course of research for successful clinical translation of basic research findings for the amelioration of liver fibrosis.

Superoxide Dismutase Administration: A Review of Proposed Human Uses

Superoxide dismutases (SODs) are metalloenzymes that play a major role in antioxidant defense against oxidative stress in the body. SOD supplementation may therefore trigger the endogenous antioxidant machinery for the neutralization of free-radical excess and be used in a variety of pathological settings. This paper aimed to provide an extensive review of the possible uses of SODs in a range of pathological settings, as well as describe the current pitfalls and the delivery strategies that are in development to solve bioavailability issues. We carried out a PubMed query, using the keywords "SOD", "SOD mimetics", "SOD supplementation", which included papers published in the English language, between 2012 and 2020, on the potential therapeutic applications of SODs, including detoxification strategies. As highlighted in this paper, it can be argued that the generic antioxidant effects of SODs are beneficial under all tested conditions, from ocular and cardiovascular diseases to neurodegenerative disorders and metabolic diseases, including diabetes and its complications and obesity. However, it must be underlined that clinical evidence for its efficacy is limited and consequently, this efficacy is currently far from being demonstrated.

Skin protective and regenerative effects of RM191A, a novel superoxide dismutase mimetic

Superoxide dismutase (SOD) is known to be protective against oxidative stress-mediated skin dysfunction. Here we explore the potential therapeutic activities of RM191A, a novel SOD mimetic, on skin. RM191A is a water-soluble dimeric copper (Cu²⁺-Cu³⁺)-centred polyglycine coordination complex. It displays 10-fold higher superoxide quenching activity compared to SOD as well as significant antioxidant, anti-inflammatory and immunomodulatory activities through beneficial modulation of several significant inflammatory cytokines in vitro and in vivo.

We tested the therapeutic potential of RM191A in a topical gel using a human skin explant model and observed that it significantly inhibits UV-induced DNA damage in the epidermis and dermis, including cyclobutane pyrimidine dimers (CPD), 8-oxo-guanine (8-oxoG) and 8-nitroguanine (8NGO). RM191A topical gel is found to be non-toxic, non-teratogenic and readily distributed in the body of mice. Moreover, it significantly accelerates excisional wound healing, reduces 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced inflammation and attenuates age-associated oxidative stress in skin, demonstrating both skin regenerative and geroprotective properties of RM191A.

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RM191A is a Cu³⁺ containing coordination complex with 10-fold higher superoxide quenching activity compared to superoxide dismutase.

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RM191A exhibits potent antioxidant, anti-inflammatory and immunomodulatory properties in vitro and in vivo.

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RM191A protects human skin explants against UV-induced oxidative stress and DNA damage.

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RM191A is non-toxic, non-teratogenic and readily bioavailable in mice.

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RM191A promotes wound healing, and attenuates TPA-induced inflammation as well as age-associated oxidative stress in mouse skin.

Croton urucurana Baillon stem bark ointment accelerates the closure of cutaneous wounds in knockout IL-10 mice

ETHNOPHARMACOLOGICAL RELEVANCE

Croton urucurana Baill. (Euphorbiaceae) is a plant used in Brazilian popular medicine for the treatment of wound healing, inflammatory diseases, gastritis, infections, and hemorrhoids.

AIM

The present study aimed to evaluate the in vivo wound healing activity of an ointment based on ethanolic extract of C. urucurana stem bark, at concentrations of 5% and 10%, and to relate it with compounds that could be associated with this activity.

MATERIALS AND METHODS

Analyses by FIA-ESI-IT-MSⁿ were carried out to investigate the chemical composition of C. urucurana. Knockout IL-10 (n = 60) mice and wild type C57 (n = 12) mice were separated into 6 groups to evaluate the wound healing activity. Knockout IL-10 mice: SAL (0.9% saline); BAS (ointment base); SS (1% silver sulfadiazine); CR1 (ointment with extract of C. urucurana 5%); CR2 (ointment with extract of C. urucurana 10%); and wild mice C57: SALC57 (Saline 0.9%). A circular wound with 10 mm in diameter was generated on the dorsal of the animals. Tissue specimen of the wounds were removed on days 7 and 14 of the treatment for histopathological, oxidative status and analyses of pro-and anti-inflammatory cytokines in scar tissue.

RESULTS

In the phytochemical profile, twelve proanthocyanidins were identified (in the form of monomers, dimers, trimers, and tetramers), based on (epi)catechin and (epi)gallocatechin. Furthermore, two quercetin derivatives and two alkaloids were detected. The groups treated with CR1 and CR2 ointments presented higher rate of wound closure, increased total number of cells, mast cells, blood vessels and higher deposition of type III and I collagen. In addition, they showed increased amount of pro-inflammatory cytokines (IL- 2 and IFN-γ), and anti-inflmatory cytokines (IL-4), on the 7th day of treatment.

CONCLUSION

The results presented support the popular use of preparations based on the bark of C. urucurana as a healing compound.

A porcine acellular dermal matrix induces human fibroblasts to secrete hyaluronic acid by activating JAK2/STAT3 signalling

Human facial skin undergoes continuous ageing over a lifespan. At present, facial skin rejuvenation is mainly achieved by injecting filling materials. However, conventional materials lack long-term beneficial effects and can only rejuvenate the skin temporarily by physical filling. To overcome this shortcoming, this study developed a porcine acellular dermal matrix with a porous three-dimensional scaffold structure and containing natural growth factors (3D-GF-PADM). The average size of the 3D-GF-PADM particles was 33.415 μm, and the dynamic viscosity and elastic modulus were within ranges suitable for clinical applications. Our study revealed that the 3D-GF-PADM exhibited an extremely low α-gal epitope number (3.15 ± 0.84 × 10¹¹/mg) and DNA content, and no immunotoxicity, but contained abundant TGF-β1, VEGF and other growth factors. More importantly, this 3D-GF-PADM actively induced the synthesis of hyaluronic acid by fibroblasts of the host skin. Study at the molecular level further demonstrated that the 3D-GF-PADM activated the JAK2/STAT3 pathway, resulting in the upregulation of HAS2 expression, which led to an increase in hyaluronic acid synthesis. Our study developed a novel 3D-GF-PADM that can actively induce hyaluronic acid synthesis, which may be used clinically as a skin filling material to achieve long-term skin rejuvenation.

By activating the JAK2/STAT3 pathway, 3D-GF-PADM induces the production of hyaluronic acid in human fibroblasts.

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.

Impaired Neovascularization in Aging

Significance: The skin undergoes an inevitable degeneration as an individual ages. As intrinsic and extrinsic factors degrade the structural integrity of the skin, it experiences a critical loss of function and homeostatic stability. Thus, aged skin becomes increasingly susceptible to injury and displays a prolonged healing process. Recent Advances: Several studies have found significant differences during wound healing between younger and older individuals. The hypoxia-inducible factor 1-alpha (HIF-1α) signaling pathway has recently been identified as a major player in wound healing. Hypoxia-inducible factors (HIFs) are pleiotropic key regulators of oxygen homeostasis. HIF-1α is essential to neovascularization through its regulation of cytokines, such as SDF-1α (stromal cell-derived factor 1-alpha) and has been shown to upregulate the expression of genes important for a hypoxic response. Prolyl hydroxylase domain proteins (PHDs) and factor inhibiting HIF effectively block HIF-1α signaling in normoxia through hydroxylation, preventing the signaling cascade from activating, leading to impaired tissue survival. Critical Issues: Aged wounds are a major clinical burden, resisting modern treatment and costing millions in health care each year. At the molecular level, aging has been shown to interfere with PHD regulation, which in turn prevents HIF-1α from activating gene expression, ultimately leading to impaired healing. Other studies have identified loss of function in cells during aging, impeding processes such as angiogenesis. Future Directions: An improved understanding of the regulation of molecular mediators, such as HIF-1α and PHD, will allow for manipulation of the various factors underlying delayed wound healing in the aged. The findings highlighted in this may facilitate the development of potential therapeutic approaches involved in the alteration of cellular dynamics and aging.

Insights into superoxide dismutase 3 in regulating biological and functional properties of mesenchymal stem cells

Mesenchymal stem cells (MSCs) have been extensively studied and implicated for the cell-based therapy in several diseases due to theirs immunomodulatory properties. Embryonic stem cells and induced-pluripotent stem cells have either ethical issues or concerns regarding the formation of teratomas, introduction of mutations into genome during prolonged culture, respectively which limit their uses in clinical settings. On the other hand, MSCs also encounter certain limitation of circumscribed survival and reduced immunomodulatory potential during transplantation. Plethora of research is undergoing to improve the efficacy of MSCs during therapy. Several compounds and novel techniques have been employed to increase the therapeutic potency of MSCs. MSCs secreted superoxide dismutase 3 (SOD3) may be the mechanism for exhibiting direct antioxidant activities by MSCs. SOD3 is a well known antioxidant enzyme and recently known to possess immunomodulatory properties. Along with superoxide scavenging property, SOD3 also displays anti-angiogenic, anti-chemotactic and anti-inflammatory functions in both enzymatic and non-enzymatic manners. In this review, we summarize the emerging role of SOD3 secreted from MSCs and SOD3’s effects during cell-based therapy.

Genome wide analysis of gene expression changes in skin from patients with type 2 diabetes

Non-healing chronic ulcers are a serious complication of diabetes and are a major healthcare problem. While a host of treatments have been explored to heal or prevent these ulcers from forming, these treatments have not been found to be consistently effective in clinical trials. An understanding of the changes in gene expression in the skin of diabetic patients may provide insight into the processes and mechanisms that precede the formation of non-healing ulcers. In this study, we investigated genome wide changes in gene expression in skin between patients with type 2 diabetes and non-diabetic patients using next generation sequencing. We compared the gene expression in skin samples taken from 27 patients (13 with type 2 diabetes and 14 non-diabetic). This information may be useful in identifying the causal factors and potential therapeutic targets for the prevention and treatment of diabetic related diseases.

Fluorescent Light Energy (FLE) Acts on Mitochondrial Physiology Improving Wound Healing

Fluorescent light energy (FLE) has been used to treat various injured tissues in a non-pharmacological and non-thermal fashion. It was applied to stimulate cell proliferation, accelerate healing in chronic and acute wounds, and reduce pain and inflammation. FLE has been shown to reduce pro-inflammatory cytokines while promoting an environment conducive to healing. A possible mechanism of action of FLE is linked to regulation of mitochondrial homeostasis. This work aims to investigate the effect of FLE on mitochondrial homeostasis in an in vitro model of inflammation. Confocal microscopy and gene expression profiling were performed on cultures of inflamed human dermal fibroblasts treated with either direct light from a multi-LED lamp, or FLE from either an amorphous gel or sheet hydrogel matrix. Assessment using confocal microscopy revealed mitochondrial fragmentation in inflamed cells, likely due to exposure to inflammatory cytokines, however, mitochondrial networks were restored to normal 24-h after treatment with FLE. Moreover, gene expression analysis found that treatment with FLE resulted in upregulation of uncoupling protein 1 (UCP1) and carnitine palmitoyltransferase 1B (CPT1B) genes, which encode proteins favoring mitochondrial ATP production through oxidative phosphorylation and lipid β-oxidation, respectively. These observations demonstrate a beneficial effect of FLE on mitochondrial homeostasis in inflamed cells.

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.

Copper transporters and copper chaperones: roles in cardiovascular physiology and disease

Copper (Cu) is an essential micronutrient but excess Cu is potentially toxic. Its important propensity to cycle between two oxidation states accounts for its frequent presence as a cofactor in many physiological processes through Cu-containing enzymes, including mitochondrial energy production (via cytochrome c-oxidase), protection against oxidative stress (via superoxide dismutase), and extracellular matrix stability (via lysyl oxidase). Since free Cu is potentially toxic, the bioavailability of intracellular Cu is tightly controlled by Cu transporters and Cu chaperones. Recent evidence reveals that these Cu transport systems play an essential role in the physiological responses of cardiovascular cells, including cell growth, migration, angiogenesis and wound repair. In response to growth factors, cytokines, and hypoxia, their expression, subcellular localization, and function are tightly regulated. Cu transport systems and their regulators have also been linked to various cardiovascular pathophysiologies such as hypertension, inflammation, atherosclerosis, diabetes, cardiac hypertrophy, and cardiomyopathy. A greater appreciation of the central importance of Cu transporters and Cu chaperones in cell signaling and gene expression in cardiovascular biology offers the possibility of identifying new therapeutic targets for cardiovascular disease.

Deferoxamine can prevent pressure ulcers and accelerate healing in aged mice

Chronic wounds are a significant medical and economic problem worldwide. Individuals over the age of 65 are particularly vulnerable to pressure ulcers and impaired wound healing. With this demographic growing rapidly, there is a need for effective treatments. We have previously demonstrated that defective hypoxia signaling through destabilization of the master hypoxia-inducible factor 1α (HIF-1α) underlies impairments in both aging and diabetic wound healing. To stabilize HIF-1α, we developed a transdermal delivery system of the Food and Drug Administration-approved small molecule deferoxamine (DFO) and found that transdermal DFO could both prevent and treat ulcers in diabetic mice. Here, we demonstrate that transdermal DFO can similarly prevent pressure ulcers and normalize aged wound healing. Enhanced wound healing by DFO is brought about by stabilization of HIF-1α and improvements in neovascularization. Transdermal DFO can be rapidly translated into the clinic and may represent a new approach to prevent and treat pressure ulcers in aged patients.

Strychnos pseudoquina modulates the morphological reorganization of the scar tissue of second intention cutaneous wounds in rats

Natural substances are used in folk medicines to treat injuries. Strychnos pseudoquina has scarring, antipyretic, and antimalarial actions. The present study aimed to analyze the effect of S. pseudoquina on cutaneous wound healing in rats. The S. pseudoquina extract was submitted to phytochemical prospection. The levels of flavonoids and total phenolic compounds in the extract were 50.7 mg/g and 2.59 mg/g, respectively. Thirty Wistar rats were individualized in cages with food and water ad libitum (registration no. 730/2014). After anesthesia, three circular wounds (12mm diameter) were made in the animals, which were randomly separated into five treatments: Sal, saline; VO, ointment vehicles (lanolin and Vaseline); SS, positive control (silver sulfadiazine 1%); LE 5, freeze-dried extract 5%; and LE 10, lyophilized extract 10%. The animals were treated with the ointment daily for 21 days. Every seven days, the area and the rate of wound contraction were evaluated. Tissue samples were removed for histopathological analysis of the number of mast cells, elastic and collagen fibers, and biochemical analyses, quantification of malondialdehyde (MDA), carbonylated proteins (PCN), superoxide dismutase (SOD), catalase (CAT), transforming growth factor β (TGF-β), Interleukin 10 (IL-10) and tumor necrosis factor (TNF). The number of mast cells, collagen and elastic fibers in the rat wounds were higher in the treatments with the plant. The extract also stimulated the activity of antioxidant enzymes, particularly SOD, presenting high levels, and maintained low levels of PCN. The TGF-β and IL-10 concentration was higher in the LE5 and LE10 treatment of the extract than in the Sal, OV and SS treatments on day 7. The ointment based on S. pseudoquina closed the wound faster and accelerated wound healing in animals.

Redox Signaling in Diabetic Wound Healing Regulates Extracellular Matrix Deposition

SIGNIFICANCE

Impaired wound healing is a major complication of diabetes, and can lead to development of chronic foot ulcers in a significant number of patients. Despite the danger posed by poor healing, very few specific therapies exist, leaving patients at risk of hospitalization, amputation, and further decline in overall health. Recent Advances: Redox signaling is a key regulator of wound healing, especially through its influence on the extracellular matrix (ECM). Normal redox signaling is disrupted in diabetes leading to several pathological mechanisms that alter the balance between reactive oxygen species (ROS) generation and scavenging. Importantly, pathological oxidative stress can alter ECM structure and function.

CRITICAL ISSUES

There is limited understanding of the specific role of altered redox signaling in the diabetic wound, although there is evidence that ROS are involved in the underlying pathology.

FUTURE DIRECTIONS

Preclinical studies of antioxidant-based therapies for diabetic wound healing have yielded promising results. Redox-based therapeutics constitute a novel approach for the treatment of wounds in diabetes patients that deserve further investigation. Antioxid. Redox Signal. 27, 823-838.

Age-associated intracellular superoxide dismutase deficiency potentiates dermal fibroblast dysfunction during wound healing

Reactive oxygen species (ROS) impair wound healing through destructive oxidation of intracellular proteins, lipids and nucleic acids. Intracellular superoxide dismutase (SOD1) regulates ROS levels and plays a critical role in tissue homoeostasis. Recent evidence suggests that age-associated wound healing impairments may partially result from decreased SOD1 expression. We investigated the mechanistic basis by which increased oxidative stress links to age-associated impaired wound healing. Fibroblasts were isolated from unwounded skin of young and aged mice, and myofibroblast differentiation was assessed by measuring α-smooth muscle actin and collagen gel contraction. Excisional wounds were created on young and aged mice to study the healing rate, ROS levels and SOD1 expression. A mechanistic link between oxidative stress and fibroblast function was explored by assessing the TGF-β1 signalling pathway components in young and aged mice. Age-related wounds displayed reduced myofibroblast differentiation and delayed wound healing, consistent with a decrease in the in vitro capacity for fibroblast-myofibroblast transition following oxidative stress. Young fibroblasts with normal SOD1 expression exhibited increased phosphorylation of ERK in response to elevated ROS. In contrast, aged fibroblasts with reduced SOD1 expression displayed a reduced capacity to modulate intracellular ROS. Collectively, age-associated wound healing impairments are associated with fibroblast dysfunction that is likely the result of decreased SOD1 expression and subsequent dysregulation of intracellular ROS. Strategies targeting these mechanisms may suggest a new therapeutic approach in the treatment of chronic non-healing wounds in the aged population.

The molecular biology in wound healing & non-healing wound

The development of molecular biology and other new biotechnologies helps us to recognize the wound healing and non-healing wound of skin in the past 30 years. This review mainly focuses on the molecular biology of many cytokines (including growth factors) and other molecular factors such as extracellular matrix (ECM) on wound healing. The molecular biology in cell movement such as epidermal cells in wound healing was also discussed. Moreover many common chronic wounds such as pressure ulcers, leg ulcers, diabetic foot wounds, venous stasis ulcers, etc. usually deteriorate into non-healing wounds. Therefore the molecular biology such as advanced glycation end products (AGEs) and other molecular factors in diabetes non-healing wounds were also reviewed.

Comparison of the Hydroxylase Inhibitor Dimethyloxalylglycine and the Iron Chelator Deferoxamine in Diabetic and Aged Wound Healing

BACKGROUND

A hallmark of diabetes mellitus is the breakdown of almost every reparative process in the human body, leading to critical impairments of wound healing. Stabilization and activity of the transcription factor hypoxia-inducible factor (HIF)-1α is impaired in diabetes, leading to deficits in new blood vessel formation in response to injury. In this article, the authors compare the effectiveness of two promising small-molecule therapeutics, the hydroxylase inhibitor dimethyloxalylglycine and the iron chelator deferoxamine, for attenuating diabetes-associated deficits in cutaneous wound healing by enhancing HIF-1α activation.

METHODS

HIF-1α stabilization, phosphorylation, and transactivation were measured in murine fibroblasts cultured under normoxic or hypoxic and low-glucose or high-glucose conditions following treatment with deferoxamine or dimethyloxalylglycine. In addition, diabetic wound healing and neovascularization were evaluated in db/db mice treated with topical solutions of either deferoxamine or dimethyloxalylglycine, and the efficacy of these molecules was also compared in aged mice.

RESULTS

The authors show that deferoxamine stabilizes HIF-1α expression and improves HIF-1α transactivity in hypoxic and hyperglycemic states in vitro, whereas the effects of dimethyloxalylglycine are significantly blunted under hyperglycemic hypoxic conditions. In vivo, both dimethyloxalylglycine and deferoxamine enhance wound healing and vascularity in aged mice, but only deferoxamine universally augmented wound healing and neovascularization in the setting of both advanced age and diabetes.

CONCLUSION

This first direct comparison of deferoxamine and dimethyloxalylglycine in the treatment of impaired wound healing suggests significant therapeutic potential for topical deferoxamine treatment in ischemic and diabetic disease.

Early induction of NRF2 antioxidant pathway by RHBDF2 mediates rapid cutaneous wound healing

Rhomboid family protein RHBDF2, an upstream regulator of the epidermal growth factor (EGF) receptor signaling, has been implicated in cutaneous wound healing. However, the underlying molecular mechanisms are still emerging. In humans, a gain-of-function mutation in the RHBDF2 gene accelerates cutaneous wound healing in an EGFR-dependent manner. Likewise, a gain-of-function mutation in the mouse Rhbdf2 gene (Rhbdf2^cub/cub) shows a regenerative phenotype (rapid ear-hole closure) resulting from constitutive activation of the EGFR pathway. Because the RHBDF2-regulated EGFR pathway is relevant to cutaneous wound healing in humans, we used Rhbdf2^cub/cub mice to investigate the biological networks and pathways leading to accelerated ear-hole closure, with the goal of identifying therapeutic targets potentially effective in promoting wound healing in humans. Comparative transcriptome analysis of ear pinna tissue from Rhbdf2^cub/cub and Rhbdf2^+/+ mice at 0h, 15min, 2h, and 24h post-wounding revealed an early induction of the nuclear factor E2-related factor 2 (NRF2)-mediated anti-oxidative pathway (0h and 15min), followed by the integrin-receptor aggregation pathway (2h) as early-stage events immediately and shortly after wounding in Rhbdf2^cub/cub mice. Additionally, we observed genes enriched for the Fc fragment of the IgG receptor IIIa (FCGR3A)-mediated phagocytosis pathway 24h post-wounding. Although cutaneous wound repair in healthy individuals is generally non-problematic, it can be severely impaired due to aging, diabetes, and chronic inflammation. This study suggests that activation of the NRF2-antioxidant pathway by rhomboid protein RHBDF2 might be beneficial in treating chronic non-healing wounds.

Endothelial Antioxidant-1: a Key Mediator of Copper-dependent Wound Healing in vivo

Copper (Cu), an essential nutrient, promotes wound healing, however, target of Cu action and underlying mechanisms remain elusive. Cu chaperone Antioxidant-1 (Atox1) in the cytosol supplies Cu to the secretory enzymes such as lysyl oxidase (LOX), while Atox1 in the nucleus functions as a Cu-dependent transcription factor. Using mouse cutaneous wound healing model, here we show that Cu content (by X-ray Fluorescence Microscopy) and nuclear Atox1 are increased after wounding, and that wound healing with and without Cu treatment is impaired in Atox1^-/- mice. Endothelial cell (EC)-specific Atox1^-/- mice and gene transfer of nuclear-target Atox1 in Atox1^-/- mice reveal that Atox1 in ECs as well as transcription factor function of Atox1 are required for wound healing. Mechanistically, Atox1^-/- mice show reduced Atox1 target proteins such as p47phox NADPH oxidase and cyclin D1 as well as extracellular matrix Cu enzyme LOX activity in wound tissues. This in turn results in reducing O₂^- production in ECs, NFkB activity, cell proliferation and collagen formation, thereby inhibiting angiogenesis, macrophage recruitment and extracellular matrix maturation. Our findings suggest that Cu-dependent transcription factor/Cu chaperone Atox1 in ECs plays an important role to sense Cu to accelerate wound angiogenesis and healing.