Genistein accelerates refractory wound healing by suppressing superoxide and FoxO1/iNOS pathway in type 1 diabetes

Polyphenols in wound healing: unlocking prospects with clinical applications

Wound healing is a multifaceted, complex process that factors like aging, metabolic diseases, and infections may influence. The potentiality of polyphenols, natural compounds, has shown anti-inflammatory and antimicrobial properties in promoting wound healing and their potential applications in wound management. The studies reviewed indicate that polyphenols have multiple mechanisms that promote wound healing. This involves enhancing antioxidant defenses, reducing oxidative stress, modulating inflammatory responses, improving healing times, reducing infection rates, and enhancing tissue regeneration in clinical trials and in vivo and in vitro studies. Polyphenols have been proven to be effective in managing hard-to-heal wounds, especially in diabetic and elderly populations. Polyphenols have shown significant benefits in promoting angiogenesis and stimulating collagen synthesis. Polyphenol treatment has been demonstrated to have therapeutic effects in wound healing and chronic wound management. Their ability to regulate key healing processes makes them suitable for new wound care products and treatments. Future research should enhance formulations and delivery methods to optimize polyphenols' bioavailability and therapeutic efficacy in wound management approaches.

Cutaneous wound healing in type 2 diabetes db/db mice was impaired with specific changes in proinflammatory cytokine expression

In db/db mice, cutaneous wound healing was delayed, and excessive wound exudates enlarged the wound. However, the relationship between enlarged wounds and proinflammatory cytokine expression remains unknown. Therefore, we investigated the expression of proinflammatory cytokines Tnf-α and Il-6 in cutaneous wound healing with diabetes. In this study, 12 C57BL/6J mice (wild-type: WT) and 14 db/db mice were subjected to full-thickness wound injuries. Wound healing was assessed until day 14, and wound tissues were harvested on days 7, 9, 11, and 14. The wound areas increased for 4 days, gradually increased until day 9, and stabilized until day 14 in the db/db group, but increased for 3 days, rapidly decreased until day 12, and gradually decreased until day 14 in the WT group. On day 14, the wound area in the db/db group was significantly larger than that in the WT group (p < 0.01). The relative expressions of the Tnf-α and Il-6 in the db/db group were significantly higher than those in the WT group on days 7-14, and on days 11 and 14, respectively (p < 0.05). Our study showed that cutaneous wound healing was delayed with wound expansion and the expression of Tnf-α and Il-6 was high throughout the measurement time points in db/db mice. These abnormal expressions could influence impaired cutaneous wound healing in diabetic mellitus.

Recent advancements in drug delivery system of flavonoids with a special emphasis on the flavanone naringenin: exploring their application in wound healing and associated processes

Numerous flavonoids have been identified in citrus fruits which show potential to cure several complex diseases. These natural polyphenolic bioactive compounds are the secondary metabolites of various plants, among which naringenin has been explored in several pre-clinical research for its beneficial role in promoting health by modulating various biochemical processes. Its antioxidant, anti-inflammatory, and anti-microbial effects have been projected toward healing of wounds. Further, its application has also been shown to regrow vascular networks, which are known to facilitate the healing of chronic wounds. Thus, the potential of naringenin to modulate various molecular pathways aids in the healing process of wounds. Considering the recent literature, an update has been attempted to present the correlation between the healing mechanisms of wounds by the application of naringenin. Furthermore, the application of naringenin is challenging because of its properties of poor solubility and limited permeability, which can be overcome by the nanotechnology platform. Thus, several nanocarriers that have been employed for the improvement of naringenin delivery are highlighted. Thereby, it can be concluded that a suitable nanocarrier of naringenin could be an effective tool in treating wounds to improve the quality of life of such patients.

Advances in arthropod-inspired bionic materials for wound healing

Arthropods contain lots of valuable bionic information from the composition to the special structure of the body. In particular, the rapid self-healing ability and antibacterial properties are amazing. Biomimetic materials for arthropods have been helpful methods for wound management. Here, we have identified four major dimensions needed to create biomimetic materials for arthropods, including ingredient, behavior, structure and internal reaction. According to different dimensions, we classify and introduce the reported arthropod biomimetic materials. Antibacterial, hemostatic and healing promotion are the main functions of the active compositions of arthropods developed by humans, and most of them play a drug effect. We believe that an ideal biomimetic material of arthropod should have the effect on promoting wound healing through the advantages of structure and composition. The special macroscopic and microscopic structure of the epidermis may provide good mechanical support for biomimetic materials. The drug release regularity in the bionic materials can be referred to the aggressive and secretory behavior of arthropods. The synthesis of substances in arthropods is also noteworthy, and we can learn these special reactions to complete the fast preparation of materials. Arthropod-inspired bionic materials have broad innovation and application prospects in the field of wound repair.

Shengji ointment combined with bromelain promotes granulation of exposed tendons in diabetic foot ulcers: A multicenter, randomized, positive-controlled clinical trial

Background

Exposed, infected and necrotic tendons often occur in the middle and late stages of diabetic foot ulcers (DFUs). The exposed tendon is both a potential source and route of infection, which prolongs the treatment period and affects recovery, leading to amputation and even death. Therefore, management of the exposed tendon in patients with DFU is the key to treatment. This study aimed to evaluate the clinical efficacy of Shengji ointment combined with bromelain in the treatment of DFU with tendon exposure and to provide clinical treatment options and evidence-based medicine.

Methods

This study was a multicenter, nonblinded, randomized, positive controlled clinical trial involving 180 patients with DFU with tendon exposure at four tertiary-grade A-class hospitals. The included patients were randomly assigned 1:1 to an observation group (n = 90) that received Shengji ointment combined with bromelain and a control group (n = 90) that received hydrocolloid dressing, with dressing changes once daily for 4 weeks. Patients in both groups continued with conventional treatments, such as blood glucose and blood pressure medication, lipid regulation, and antiplatelets. The primary outcome measure was wound coverage with granulation tissue. The secondary outcome measures included the wound healing rate, time to granulation, Maryland foot score, time to debridement of necrotic tendon tissue, and granulation tissue score. We performed measurements before enrollment and after the end of treatment for comparison.

Results

There was no significant difference in the baseline data between the two groups before treatment (P > 0.05). After treatment, the primary outcome indicators of the two groups were compared, and the wound granulation tissue coverage rate of the treatment group was greater than that of the control group (P = 0.003). For the secondary outcome outcomes, the wound healing rate, time to granulation, Maryland foot function score, time to debridement of necrotic tendon tissue, and granulation tissue score in the treatment group were significantly better than those in the control group (P < 0.05). There was no significant difference in the incidence of adverse reactions between the two groups (P = 0.444).

Conclusions

Shengji ointment combined with bromelain effectively promotes the removal of exposed necrotic tendons in patients with DFU, promotes the regeneration of healthy granulation tissue, accelerates wound healing, and protects the limb and its function. It also appears to be safe as an intervention for the treatment of patients with DFU.

Trial registration

The study protocol was registered in the Chinese Clinical Trial Registry (ChiCTR) under the code ChiCTR2000039327 on October 23, 2020. The public title is "Study on evidence-based evaluation and therapeutic mechanism of integrated Chinese and Western medicine for treatment of diabetic foot - An evidence-based evaluation of The combination of Rubber Shengji Paste and compound bromelain to promote the healing of the exposed wound of diabetic foot tendon".

Greener healing: sustainable nanotechnology for advanced wound care

Wound healing involves a carefully regulated sequence of events, encompassing pro-inflammatory and anti-inflammatory stages, tissue regeneration, and remodeling. However, in individuals with diabetes, this process gets disrupted due to dysregulation caused by elevated glucose levels and pro-inflammatory cytokines in the bloodstream. Consequently, the pro-inflammatory stage is prolonged, while the anti-inflammatory phase is delayed, leading to impaired tissue regeneration and remodeling with extended healing time. Furthermore, the increased glucose levels in open wounds create an environment conducive to microbial growth and tissue sepsis, which can escalate to the point of limb amputation. Managing diabetic wounds requires meticulous care and monitoring due to the lack of widely available preventative and therapeutic measures. Existing clinical interventions have limitations, such as slow recovery rates, high costs, and inefficient drug delivery methods. Therefore, exploring alternative avenues to develop effective wound-healing treatments is essential. Nature offers a vast array of resources in the form of secondary metabolites, notably polyphenols, known for their antimicrobial, anti-inflammatory, antioxidant, glucose-regulating, and cell growth-promoting properties. Additionally, nanoparticles synthesized through environmentally friendly methods hold promise for wound healing applications in diabetic and non-diabetic conditions. This review provides a comprehensive discussion and summary of the potential wound-healing abilities of specific natural polyphenols and their nanoparticles. It explores the mechanisms of action underlying their efficacy and presents effective formulations for promoting wound-healing activity.

ROCK1 inhibition improves wound healing in diabetes via RIPK4/AMPK pathway

Refractory wounds are a severe complication of diabetes mellitus that often leads to amputation because of the lack of effective treatments and therapeutic targets. The pathogenesis of refractory wounds is complex, involving many types of cells. Rho-associated protein kinase-1 (ROCK1) phosphorylates a series of substrates that trigger downstream signaling pathways, affecting multiple cellular processes, including cell migration, communication, and proliferation. The present study investigated the role of ROCK1 in diabetic wound healing and molecular mechanisms. Our results showed that ROCK1 expression significantly increased in wound granulation tissues in diabetic patients, streptozotocin (STZ)-induced diabetic mice, and db/db diabetic mice. Wound healing and blood perfusion were dose-dependently improved by the ROCK1 inhibitor fasudil in diabetic mice. In endothelial cells, fasudil and ROCK1 siRNA significantly elevated the phosphorylation of adenosine monophosphate-activated protein kinase at Thr172 (pThr172-AMPKα), the activity of endothelial nitric oxide synthase (eNOS), and suppressed the levels of mitochondrial reactive oxygen species (mtROS) and nitrotyrosine formation. Experiments using integrated bioinformatics analysis and coimmunoprecipitation established that ROCK1 inhibited pThr172-AMPKα by binding to receptor-interacting serine/threonine kinase 4 (RIPK4). These results suggest that fasudil accelerated wound repair and improved angiogenesis at least partially through the ROCK1/RIPK4/AMPK pathway. Fasudil may be a potential treatment for refractory wounds in diabetic patients.

A self-healing crosslinked-xanthan gum/soy protein based film containing halloysite nanotube and propolis with antibacterial and antioxidant activity for wound healing

Traumatic multidrug-resistant bacterial infections are the most threat to wound healing. Lower extremity wounds under diabetic conditions display a significant delay during the healing process. To overcome these challenges, the utilization of protein-based nanocomposite dressings is crucial in implementing a successful regenerative medicine approach. These dressings hold significant potential as polymer scaffolds, allowing them to mimic the properties of the extracellular matrix (ECM). So, the objective of this study was to develop a nanocomposite film using dialdehyde-xanthan gum/soy protein isolate incorporated with propolis (PP) and halloysite nanotubes (HNTs) (DXG-SPI/PP/HNTs). In this protein-polysaccharide hybrid system, the self-healing capability was demonstrated through Schiff bonds, providing a favorable environment for cell encapsulation in the field of tissue engineering. To improve the properties of the DXG-SPI film, the incorporation of polyphenols found in PP, particularly flavonoids, is proposed. The synthesized films were subjected to investigations regarding degradation, degree of swelling, and mechanical characteristics. Additionally, halloysite nanotubes (HNTs) were introduced into the DXG-SPI/PP nanocomposite films as a reinforcing filler with varying concentrations of 3 %, 5 %, and 7 % by weight. The scanning electron microscope (SEM) analysis confirmed the proper embedding and dispersion of HNTs onto the DXG-SPI/PP nanocomposite films, leading to functional interfacial interactions. The structure and crystallinity of the synthesized nanocomposite films were characterized using Fourier Transform Infrared Spectrometry (FTIR) and X-ray diffraction (XRD), respectively. Moreover, the developed DXG-SPI/PP/HNTs nanocomposite films significantly improved cell growth of NIH-3T3 fibroblast cells in the presence of PP and HNTs, indicating their cytocompatibility. The antibacterial activity of the nanocomposite was evaluated against Escherichia coli (E. Coli) and Staphylococcus aureus (S. Aureus), which are commonly associated with wound infections. Overall, our findings suggest that the synthesis of DXG-SPI/PP/HNTs nanocomposite scaffolds holds great promise as a clinically relevant biomaterial and exhibits strong potential for numerous challenging biomedical applications.

Small molecule conjugates with selective estrogen receptor β agonism promote anti-aging benefits in metabolism and skin recovery

Estrogen is imperative to mammalian reproductivity, metabolism, and aging. However, the hormone activating estrogen receptor (ERs) α can cause major safety concerns due to the enrichment of ERα in female tissues and certain malignancies. In contrast, ERβ is more broadly expressed in metabolic tissues and the skin. Thus, it is desirable to generate selective ERβ agonist conjugates for maximizing the therapeutic effects of ERs while minimizing the risks of ERα activation. Here, we report the design and production of small molecule conjugates containing selective non-steroid ERβ agonists Gtx878 or genistein. Treatment of aged mice with our synthesized conjugates improved aging-associated declines in insulin sensitivity, visceral adipose integrity, skeletal muscle function, and skin health, with validation in vitro. We further uncovered the benefits of ERβ conjugates in the skin using two inducible skin injury mouse models, showing increased skin basal cell proliferation, epidermal thickness, and wound healing. Therefore, our ERβ-selective agonist conjugates offer novel therapeutic potential to improve aging-associated conditions and aid in rejuvenating skin health.

Superporous soy protein isolate matrices as superabsorbent dressings for successful management of highly exuding wounds: In vitro and in vivo characterization

Soy protein isolate (SPI) has received widespread attention of the biomedical research community primarily due to its good biocompatibility, biodegradability, high availability and low cost. Herein, glutaraldehyde cross-linked microporous sponge-like SPI scaffolds were prepared using the cryogelation technique for tissue engineering applications. The prepared SPI scaffolds possess an interconnected porous structure with approximately 90% porosity and an average pore size in the range of 45-92 μm. The morphology, porosity, swelling capacity and degradation rate of the cryogels were found to be dependent on the concentration of polymer to crosslinking agent. All cryogels were found to be elastic and able to maintain physical integrity even after being compressed to one-fifth of their original length during cyclic compression analysis. These cryogels showed excellent mechanical properties, immediate water-triggered shape restoration and absorption speed. Furthermore, cryogels outperformed cotton and gauze in terms of blood clotting and blood cell adherence. The in vitro and in vivo studies demonstrated the potency of SPI scaffolds for skin tissue engineering applications. Our findings showed that crosslinking with glutaraldehyde had no detrimental effects on cell viability. In addition, an in vivo wound healing study in rats validated them as good potential wound dressing materials.

Innovative Wound Healing Hydrogel Containing Chicken Feather Keratin and Soy Isoflavone Genistein: In Vivo Studies

The current study was performed to isolate keratin from chicken feathers with an intention to develop a keratin-genistein wound-healing hydrogel, along with its in vivo analysis. Pre-formulation aspects were analysed by using FTIR; SEM; HPTLC, while gel was characterized for gel strength, viscosity, spreadability, drug content, etc. Additionally, an in vivo study along with biochemical factors against pro-inflammatory factors and histopathological studies were conducted to determine possible wound-healing and anti-inflammatory effects. Pre-formulation studies revealed the presence of amide bonds with region of dense fibrous keratin and an internal porous network in extracted keratin, which corresponds with standard keratin. Evaluation of optimised keratin-genistein hydrogel indicated the development of neutral, non-sticky hydrogel which spread evenly on the skin. In vivo studies in rats indicate higher degrees of wound-healing in combined hydrogel (94.65%) for a duration of 14 days as compared to an individual hydrogel formulation with the development of the epidermis and excessive proliferation of fibrous connective tissue indicating wound repair. Furthermore, the hydrogel inhibited the overexpression of IL-6 gene along with other pro-inflammatory factors, indicating its anti-inflammatory effects. In order to find out the possibility of closure of wounds and anti-inflammatory properties of the novel product, an in vivo investigation into the healing of wounds in laboratory animals was carried out through biochemical (ELISA and qRT-PCR) analyses against inflammatory markers (IL-2, IL-6, IL-1, IL-10, and COX-2) and histopathological (liver, skin, and the kidneys) investigations. Based on the results, we conclude that keratin-genistein hydrogel is a promising therapeutic molecule for the management of wound repair.

Antimicrobial activity and wound healing effect of a novel natural ointment: an in vitro and in vivo study

Infection and pathological disorders, such as cellular disorders, ischaemia, neuropathy and angiogenesis, are considered the most critical factors which cause a delay in the wound healing process in patients with diabetes. This study aimed to investigate the effect of an ointment based on ostrich oil containing honey, beeswax, and ethanolic extracts of Nigella sativa, propolis and Cassia angustifolia on the wound healing process of diabetic rats. Gas chromatography/mass spectrometry analysis showed caffeic acid and pinostrobin chalcone molecules present in propolis, giving antibacterial and antifungal properties to the compound. The antibacterial assessment showed the ointment had remarkable antibacterial activity against Staphylococcus aureus (8.6±0.28mm), Escherichia coli (9.4±0.31mm), Acinetobacter baumannii (7.2±0.23mm) and Pseudomonas aeruginosa (13.9±0.42mm). In vivo results showed the ointment significantly accelerated wound healing and increased collagen deposition compared with the control (p<0.05). Histopathology evaluation also showed hair follicles, sebaceous glands and vessels in the group that used the ointment. These results proved successful and diabetic wound healing was rapid. Therefore, it could be concluded that the fabricated ointment could be a suitable candidate for wound healing.

Exosomes from circ-Astn1-modified adipose-derived mesenchymal stem cells enhance wound healing through miR-138-5p/SIRT1/FOXO1 axis regulation

BACKGROUND

Wound healing impairment is a dysfunction induced by hyperglycemia and its effect on endothelial precursor cells (EPCs) in type 2 diabetes mellitus. There is increasing evidence showing that exosomes (Exos) derived from adipose-derived mesenchymal stem cells (ADSCs) exhibit the potential to improve endothelial cell function along with wound healing. However, the potential therapeutic mechanism by which ADSC Exos contribute to wound healing in diabetic mice remains unclear.

AIM

To reveal the potential therapeutic mechanism of ADSC Exos in wound healing in diabetic mice.

METHODS

Exos from ADSCs and fibroblasts were used for high-throughput RNA sequencing (RNA-Seq). ADSC-Exo-mediated healing of full-thickness skin wounds in a diabetic mouse model was investigated. We employed EPCs to investigate the therapeutic function of Exos in cell damage and dysfunction caused by high glucose (HG). We utilized a luciferase reporter (LR) assay to analyze interactions among circular RNA astrotactin 1 (circ-Astn1), sirtuin (SIRT) and miR-138-5p. A diabetic mouse model was used to verify the therapeutic effect of circ-Astn1 on Exo-mediated wound healing.

RESULTS

High-throughput RNA-Seq analysis showed that circ-Astn1 expression was increased in ADSC Exos compared with Exos from fibroblasts. Exos containing high concentrations of circ-Astn1 had enhanced therapeutic effects in restoring EPC function under HG conditions by promoting SIRT1 expression. Circ-Astn1 expression enhanced SIRT1 expression through miR-138-5p adsorption, which was validated by the LR assay along with bioinformatics analyses. Exos containing high concentrations of circ-Astn1 had better therapeutic effects on wound healing in vivo compared to wild-type ADSC Exos. Immunofluorescence and immunohistochemical investigations suggested that circ-Astn1 enhanced angiopoiesis through Exo treatment of wounded skin as well as by suppressing apoptosis through promotion of SIRT1 and decreased forkhead box O1 expression.

CONCLUSION

Circ-Astn1 promotes the therapeutic effect of ADSC-Exos and thus improves wound healing in diabetes via miR-138-5p absorption and SIRT1 upregulation. Based on our data, we advocate targeting the circ-Astn1/miR-138-5p/SIRT1 axis as a potential therapeutic option for the treatment of diabetic ulcers.

Flavonoids and their therapeutic applications in skin diseases

Flavonoids are a class of plant polyphenols found in a variety of fruits, vegetables, teas, and flowers. These compounds are present in many common dietary sources, such as green tea, wine, pomegranates, and turmeric, and possess a broad spectrum of biological activity due to their unique chemical structure. Flavonoids exhibit antioxidant, anti-inflammatory, antiviral, and anticarcinogenic properties that have been widely studied as potential therapeutics for diseases ranging from Alzheimer's disease to liver disease. There is currently significant research into therapeutic benefits of flavonoids in various skin conditions as these compounds have been shown to absorb ultraviolet radiation and modulate cancer and inflammation signaling pathways. This review discusses the current research in the application of flavonoids in skin diseases (e.g., prevention of premature photoaging, prevention and treatment of skin cancer, and promotion of skin wound healing) and their proposed mechanisms to provide a basis for future basic and translational research of flavonoids as potential drugs in the prevention and treatment of skin disorders.

Flavonoids and their therapeutic applications in skin diseases

Flavonoids are a class of plant polyphenols found in a variety of fruits, vegetables, teas, and flowers. These compounds are present in many common dietary sources, such as green tea, wine, pomegranates, and turmeric, and possess a broad spectrum of biological activity due to their unique chemical structure. Flavonoids exhibit antioxidant, anti-inflammatory, antiviral, and anticarcinogenic properties that have been widely studied as potential therapeutics for diseases ranging from Alzheimer's disease to liver disease. There is currently significant research into therapeutic benefits of flavonoids in various skin conditions as these compounds have been shown to absorb ultraviolet radiation and modulate cancer and inflammation signaling pathways. This review discusses the current research in the application of flavonoids in skin diseases (e.g., prevention of premature photoaging, prevention and treatment of skin cancer, and promotion of skin wound healing) and their proposed mechanisms to provide a basis for future basic and translational research of flavonoids as potential drugs in the prevention and treatment of skin disorders.

Natural Flavonoids as Potential Therapeutics in the Management of Diabetic Wound: A Review

Flavonoids are important bioactive phenolic compounds abundant in plants and exhibit different therapeutic potentials. A wound is a significant problem in diabetic individuals. A hyperglycaemic environment alters the normal wound-healing process and increases the risk of microbial infection, leading to hospitalization, morbidity, and amputation. Flavonoids are an important class of phytochemicals with excellent antioxidant, anti-inflammatory, antimicrobial, antidiabetic, antitumor, and wound healing property. Quercetin, hesperidin, curcumin, kaempferol, apigenin, luteolin, morin, etc. have shown their wound healing potential. Flavonoids effectively exhibit antimicrobial activity, scavenge reactive oxygen species, augment endogenous antioxidants, reduce the expression and synthesis of inflammatory cytokines (i.e. IL-1β, IL-6, TNF-α, NF-κB), inhibit inflammatory enzymes, enhance anti-inflammatory cytokine (IL-10), enhance insulin section, reduce insulin resistance, and control blood glucose level. Several flavonoids like hesperidin, curcumin, quercetin, rutin, naringin, and luteolin have shown their potential in managing diabetic wounds. Natural products that maintain glucose haemostatic, exert anti-inflammatory activity, suppress/inhibit microbial growth, modulate cytokines, inhibit matrix metalloproteinase (MMP), stimulate angiogenesis and extracellular matrix, and modulate growth factor can be considered as a potential therapeutic lead to treat diabetic wound. Flavonoids were found to play a positive role in management of diabetic wounds by regulating MMP-2, MMP-8, MMP-9, MMP-13, Ras/Raf/ MEK/ERK, PI3K/Akt, and nitric oxide pathways. Therefore, it can be assumed that flavonoids could be potential therapeutics to prevent devastating effects of diabetic wounds. This paper focused on the potential role of flavonoids in managing diabetic wounds and discussed their possible mechanism of action.

Investigation of wound healing efficiency of multifunctional eudragit/soy protein isolate electrospun nanofiber incorporated with ZnO loaded halloysite nanotubes and allantoin

One significant aspect of the current therapeutic agents employed in wound healing involves the engineering of nano polymeric scaffolds to mimic the properties of extracellular matrix (ECM). The present work aimed to prepare and evaluate Eudragit® L100 (EU) nanofibers in combination with soy protein isolate (SPI). Allantoin (Ala) with a 2 wt% was encapsulated as a model drug renowned for its anti-inflammatory and antioxidant agents. Moreover, the synthesized ZnO-halloysite nanotubes (ZHNTs) with different concentrations of 1, 3, and 5 wt% were incorporated into the EU/SPI/Ala nanofiber as a reinforcing filler and a remarkable antibacterial agent. The scanning electron microscope (SEM) analysis showed that by increasing the weight percentage of SPI from 1 % to 2.5 %, the average diameter of nanofibers decreased from 132.3 ± 51.3 nm to 126.7 ± 47.2 nm. It was 223.5 ± 95.6 nm for nanofibers containing 5 wt% ZHNTs (the optimal sample). The evaluation of in vitro release kinetics of Ala for 24 h, showed a burst release during the first 2 h and a sustained release during the subsequent times. Moreover, the structure, crystallinity, and thermal stability of synthesized nanofibers were characterized by Fourier Transform Infrared Spectrometry (FTIR), X-ray diffraction (XRD), and Thermo gravimetric analysis (TGA), respectively. In vitro degradation and mechanical characteristics of these nanofibers were studied. Furthermore, the capability of the nanofibers for cell proliferation was revealed through the MTT test and field emission scanning electron microscopy (FESEM) images of cell attachment. The antimicrobial activity of EU/SPI/Ala/ZHNTs showed that this sample with high ZHNTs content (5 w%t) had the most remarkable antibacterial activity against S. aureus. The results revealed that EU/SPI/Ala/ZHNTs mats could be promising potential wound dressings.

Exosomes from circ-Astn1-modified adipose-derived mesenchymal stem cells enhance wound healing through miR-138-5p/SIRT1/FOXO1 axis regulation

BACKGROUND

Wound healing impairment is a dysfunction induced by hyperglycemia and its effect on endothelial precursor cells (EPCs) in type 2 diabetes mellitus. There is increasing evidence showing that exosomes (Exos) derived from adipose-derived mesenchymal stem cells (ADSCs) exhibit the potential to improve endothelial cell function along with wound healing. However, the potential therapeutic mechanism by which ADSC Exos contribute to wound healing in diabetic mice remains unclear.

AIM

To reveal the potential therapeutic mechanism of ADSC Exos in wound healing in diabetic mice.

METHODS

Exos from ADSCs and fibroblasts were used for high-throughput RNA sequencing (RNA-Seq). ADSC-Exo-mediated healing of full-thickness skin wounds in a diabetic mouse model was investigated. We employed EPCs to investigate the therapeutic function of Exos in cell damage and dysfunction caused by high glucose (HG). We utilized a luciferase reporter (LR) assay to analyze interactions among circular RNA astrotactin 1 (circ-Astn1), SIRT1 and miR-138-5p. A diabetic mouse model was used to verify the therapeutic effect of circ-Astn1 on Exo-mediated wound healing.

RESULTS

High-throughput RNA-Seq analysis showed that circ-Astn1 expression was increased in ADSC Exos compared with Exos from fibroblasts. Exos containing high concentrations of circ-Astn1 had enhanced therapeutic effects in restoring EPC function under HG conditions by promoting SIRT1 expression. Circ-Astn1 expression enhanced SIRT1 expression through miR-138-5p adsorption, which was validated by the LR assay along with bioinformatics analyses. Exos containing high concentrations of circ-Astn1 had better therapeutic effects on wound healing in vivo compared to wild-type ADSC Exos. Immunofluorescence and immunohistochemical investigations suggested that circ-Astn1 enhanced angiopoiesis through Exo treatment of wounded skin as well as by suppressing apoptosis through promotion of SIRT1 and decreased forkhead box O1 expression.

CONCLUSION

Circ-Astn1 promotes the therapeutic effect of ADSC-Exos and thus improves wound healing in diabetes via miR-138-5p absorption and SIRT1 upregulation. Based on our data, we advocate targeting the circ-Astn1/miR-138-5p/SIRT1 axis as a potential therapeutic option for the treatment of diabetic ulcers.

Systematic Review of the Impact of Genistein on Diabetes Related Outcomes

Diabetes is the 8th leading cause of death in the world and the prevalence is rising in low-income countries. Cardiovascular diseases are the leading cause of death worldwide, especially for individuals with diabetes. While medications exist to treat symptoms of diabetes, lack of availability and high costs may deter their use by individuals with low incomes as well as those in low-income nations. Therefore, this systematic review was performed to determine whether genistein, a phytoestrogen found in soy products, could provide therapeutic benefits for individuals with diabetes. We searched PubMed and SCOPUS using the terms 'genistein', 'diabetes', and 'glucose' and identified 33 peer-reviewed articles that met our inclusion criteria. In general, preclinical studies demonstrated that genistein decreases body weight and circulating glucose and triglycerides concentrations while increasing insulin levels and insulin sensitivity. Genistein also delayed the onset of type 1 and type 2 diabetes. In contrast, clinical studies utilizing genistein generally reported no significant relationship between genistein and body mass, circulating glucose, A1C concentrations, or onset of type 1 diabetes. However, genistein was found to improve insulin sensitivity and serum triglyceride concentrations and delayed the onset of type 2 diabetes. In summary, preclinical and clinical studies suggest that genistein may help delay the onset of type 2 diabetes and improve several symptoms associated with the disease. Although additional research is required to confirm these findings, the results highlighted in this review provide some evidence that genistein may offer a natural approach to mitigating some of the complications associated with diabetes.

Topical estrogen application promotes cutaneous wound healing in db/db female mice with type 2 diabetes

Female sex hormones are beneficial effects for wound healing. However, till date, whether topical estrogen application can promote cutaneous wound healing in diabetes remains unclear. Therefore, the present study aimed to validate the effect of topical estrogen application on cutaneous wound healing in a type 2 diabetes db/db mice model. In total, 22 db/db female mice with type 2 diabetes and eight C57BL/6J female mice were subjected to two full-thickness wound injuries. The mice were divided into the db/db, db/db + estrogen, db/db + vehicle, and wild type (WT) groups. Wound healing was assessed until day 14. The db/db group had a significantly high wound area ratio (wound area/initial wound area) on days 3–14 and a significantly low re-epithelialization ratio on days 7 and 14. Moreover, their angiogenesis ratio was significantly low on day 7 and high on day 14. In contrast, compared with the db/db group, the db/db + estrogen group had a significantly lower wound area ratio on days 1–14 and angiogenesis ratio on day 14, thereby indicating early withdrawal of new blood vessels, as well as a significantly higher re-epithelialization ratio on days 7 and 14 and Ym1⁺ M2 macrophage/macrophage ratio on day 7. Moreover, microarray analysis showed that the top 10 upregulated or downregulated genes in the db/db group were reversed by estrogen treatment, particularly on day 14, in comparison with the WT group. Thus, topical estrogen application reduced the wound area, promoted re-epithelialization and angiogenesis, and increased the number of M2 macrophages in mice with type 2 diabetes. Furthermore, it improved the differential regulation of genes in db/db mice. Therefore, such treatment can enhance cutaneous wound healing in female mice with type 2 diabetes.

Genistein: A Review on its Anti-Inflammatory Properties

Nowadays, non-resolving inflammation is becoming a major trigger in various diseases as it plays a significant role in the pathogenesis of atherosclerosis, asthma, cancer, obesity, inflammatory bowel disease, chronic obstructive pulmonary disease, neurodegenerative disease, multiple sclerosis, and rheumatoid arthritis. However, prolonged use of anti-inflammatory drugs is usually accompanied with undesirable effects and hence more patients tend to seek for natural compounds as alternative medicine. Considering the fact above, there is an urgency to discover and develop potential novel, safe and efficacious natural compounds as drug candidates for future anti-inflammatory therapy. Genistein belongs to the flavonoid family, in the subgroup of isoflavones. It is a phytoestrogen that is mainly derived from legumes. It is a naturally occurring chemical constituent with a similar chemical structure to mammalian estrogens. It is claimed to exert many beneficial effects on health, such as protection against osteoporosis, reduction in the risk of cardiovascular disease, alleviation of postmenopausal symptoms and anticancer properties. In the past, numerous in vitro and in vivo studies have been conducted to investigate the anti-inflammatory potential of genistein. Henceforth, this review aims to summarize the anti-inflammatory properties of genistein linking with the signaling pathways and mediators that are involved in the inflammatory response as well as its toxicity profile. The current outcomes are analysed to highlight the prospect as a lead compound for drug discovery. Data was collected using PubMed, ScienceDirect, SpringerLink and Scopus databases. Results showed that genistein possessed strong anti-inflammatory activities through inhibition of various signaling pathways such as nuclear factor kappa-B (NF-κB), prostaglandins (PGs), inducible nitric oxide synthase (iNOS), proinflammatory cytokines and reactive oxygen species (ROS). A comprehensive assessment of the mechanism of action in anti-inflammatory effects of genistein is included. However, evidence for the pharmacological effects is still lacking. Further studies using various animal models to assess pharmacological effects such as toxicity, pharmacokinetics, pharmacodynamics, and bioavailability studies are required before clinical studies can be conducted. This review will highlight the potential use of genistein as a lead compound for future drug development as an anti-inflammatory agent.

Comparative effects of genistein and bisphenol A on non-alcoholic fatty liver disease in laying hens

Bisphenol A (BPA) and genistein (GEN) are selective estrogen receptor modulators, which are involved in the occurrence and development of metabolic syndrome. However, their roles in non-alcoholic fatty liver disease (NAFLD) of laying hens have not been reported. Here, we investigated the effects of different concentrations of GEN and BPA on the NAFLD of laying hens. Results showed that GEN ameliorated the high-energy and low-protein diet (HELP)-induced NAFLD by improving pathological damage, hepatic steatosis, and insulin resistance and blocking the expression of NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome-related factors. By contrast, high dose of BPA could aggravate these changes with serious symptom of NAFLD and suppress the level of ERα in the liver considerably, while GEN could reverse this phenomenon in a dose-dependent manner. In general, our research shows that the protective effect of GEN on NAFLD aims to improve the metabolic disorders and inflammation closely connected to ERα, while BPA can inhibit the expression of ERα and exacerbate the symptom of NAFLD. In conclusion, we elucidate the opposing effects of GEN and BPA in NAFLD of laying hens, thus providing a potential mechanism related to ERα and inflammation.

Wound healing properties of flavonoids: A systematic review highlighting the mechanisms of action

BACKGROUND

Flavonoids are a class of compounds with a wide variety of biological functions, being an important source of new products with pharmaceutical potential, including treatment of skin wounds.

PURPOSE

This review aimed to summarize and evaluate the evidence in the literature in respect of the healing properties of flavonoids on skin wounds in animal models.

STUDY DESIGN

This is a systematic review following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement.

METHODS

This was carried out through a specialized search of four databases: PubMed, Scopus, Web of Science and Embase. The following keyword combinations were used: "flavonoidal" OR "flavonoid" OR "flavonoidic" OR "flavonoids" AND "wound healing" as well as MeSH terms, Emtree terms and free-text words.

RESULTS

Fifty-five (55) articles met the established inclusion and exclusion criteria. Flavonoids presented effects in respect of the inflammatory process, angiogenesis, re-epithelialization and oxidative stress. They were shown to be able to act on macrophages, fibroblasts and endothelial cells by mediating the release and expression of TGF-β1, VEGF, Ang, Tie, Smad 2 and 3, and IL-10. Moreover, they were able to reduce the release of inflammatory cytokines, NFκB, ROS and the M1 phenotype. Flavonoids acted by positively regulating MMPs 2, 8, 9 and 13, and the Ras/Raf/MEK/ERK, PI3K/Akt and NO pathways.

CONCLUSION

Flavonoids are useful tools in the development of therapies to treat skin lesions, and our review provides a scientific basis for future basic and translational research.

Molecular Changes Underlying Genistein Treatment of Wound Healing: A Review

Estrogen deprivation is one of the major factors responsible for many age-related processes including poor wound healing in postmenopausal women. However, the reported side-effects of estrogen replacement therapy (ERT) have precluded broad clinical administration. Therefore, selective estrogen receptor modulators (SERMs) have been developed to overcome the detrimental side effects of ERT on breast and/or uterine tissues. The use of natural products isolated from plants (e.g., soy) may represent a promising source of biologically active compounds (e.g., genistein) as efficient alternatives to conventional treatment. Genistein as natural SERM has the unique ability to selectively act as agonist or antagonist in a tissue-specific manner, i.e., it improves skin repair and simultaneously exerts anti-cancer and chemopreventive properties. Hence, we present here a wound healing phases-based review of the most studied naturally occurring SERM.

Pueraria tuberosa: A Review on Traditional Uses, Pharmacology, and Phytochemistry

Pueraria tuberosa (Roxb. ex Willd.) DC. (Fabaceae), also known as Indian Kudzu (vidari kand), is a perennial herb distributed throughout India and other Asian countries. Traditionally, tuber and leaves of this plant have extensively been reported for nutritional and medicinal properties in Ayurveda as well as in Chinese traditional practices. The objective of the present review is to compile and update the published data on traditional uses, pharmacological potential, and phytochemistry of compounds isolated from the plant Pueraria tuberosa. P. tuberosa extracts and its purified compounds possess multiple activities such as anticancer, anticonvulsant, antidiabetic, antifertility, anti-inflammatory, antioxidant, anti-stress, antiulcerogenic, cardioprotective, hypolipidemic, hepatoprotective, immunomodulatory, nephroprotective, nootropic, neuroprotective, and wound healing. Tuber and leaf extracts of P. tuberosa contain several bioactive constituents such as puerarin, daidzein, genistein, quercetin, irisolidone, biochanin A, biochanin B, isoorientin, and mangiferin, which possess an extensive range of pharmacological activities. The extensive range of pharmacological properties of P. tuberosa provides opportunities for further investigation and presents a new approach for the treatment of ailments. Many phytochemicals have been identified and characterized from P. tuberosa; however, some of them are still unexplored, and there is no supporting data for their activities and exact mechanisms of action. Therefore, further investigations are warranted to unravel the mechanisms of action of individual constituents of this plant.

Glycyrrhizin micelle as a genistein nanocarrier: Synergistically promoting corneal epithelial wound healing through blockage of the HMGB1 signaling pathway in diabetic mice

The purpose of this study was to explore the feasibility of targeting the HMGB1 signaling pathway to treat diabetic keratopathy with a dipotassium glycyrrhizinate-based micelle ophthalmic solution encapsulating genistein (DG-Gen), and to evaluate whether these dipotassium glycyrrhizinate (DG) micelles could synergistically enhance the therapeutic effect of encapsulated genistein (Gen). An optimized DG-Gen ophthalmic solution was fabricated with a Gen/DG weight of ratio 1:15, and this formulation featured an encapsulation efficiency of 98.96 ± 0.82%, and an average particle size of 29.50 ± 2.05 nm. The DG-Gen ophthalmic solution was observed to have good in vivo ocular tolerance and excellent in vivo corneal permeation, and to remarkably improve in vitro antioxidant activity. Ocular topical application of the DG-Gen ophthalmic solution significantly prompted corneal re-epithelialization and nerve regeneration in diabetic mice, and this efficacy might be due to the inhibition of HMGB1 signaling through down-regulation of HMGB1 and its receptors RAGE and TLR4, as well as inflammatory factor interleukin (IL)-6 and IL-1β. In conclusion, these data showed that HMGB1 signaling is a potential regulation target for the treatment of diabetic keratopathy, and novel DG-micelle formulation encapsulating active agents such as Gen could synergistically cause blockage of HMGB1 signaling to prompt diabetic corneal and nerve wound healing.

Hydrogels containing soybean isoflavone aglycones-rich fraction-loaded nanoemulsions for wound healing treatment - in vitro and in vivo studies

Soybean isoflavone aglycones have been investigated as potential wound healing compounds for topical application. The aim of this study was to evaluate the wound healing properties of a soybean isoflavone aglycones-rich fraction (IAF) when incorporated into lipid nanoemulsions dispersed in acrylic-acid hydrogels. Formulations exhibited a mean droplet size in the sub 200 nm range, negative ζ-potential (-60 mV), and displayed non-Newtonian pseudoplastic behavior. The addition of a gelling agent decreased the IAF release from formulations and improved the retention of these compounds in intact porcine ear skin when compared with a control propylene glycol solution. No IAF were detected in receptor fluid of Franz-type diffusion cells. However, increasing amounts of IAF were noticed in both skin layers and the receptor fluid when the tissue was partially injured (tape stripping), or when the epidermis was completely removed. In vitro studies showed that IAF elicits an increased proliferation and migration of keratinocytes (HaCaT cell line). Subsequently, the healing effect of the formulations was evaluated in a model of dorsal wounds in rats, by assessing the size of the lesions, histology, inflammatory markers, and antioxidant activity. Overall findings demonstrated the potential of IAF-loaded formulations to promote wound healing by increasing angiogenesis by ∼200 %, reducing the lipid oxidation (TBARS) by ∼52 % and the inflammation (TNFα) by ∼35 %, while increasing re-epithelialization by ∼500 %, visualized by the epithelium thickness.

Biomimetic and estrogenic fibers promote tissue repair in mice and human skin via estrogen receptor β

The dynamic changes in estrogen levels throughout aging and during the menstrual cycle influence wound healing. Elevated estrogen levels during the pre-ovulation phase accelerate tissue repair, whereas reduced estrogen levels in post-menopausal women lead to slow healing. Although previous reports have shown that estrogen may potentiate healing by triggering the estrogen receptor (ER)-β signaling pathway, its binding to ER-α has been associated with severe collateral effects and has therefore limited its use as a therapeutic agent. To this end, soy phytoestrogens, which preferentially bind to the ER-β, are currently being explored as a safer therapeutic alternative to estrogen. However, the development and evaluation of phytoestrogen-based materials as local ER-β modulators remains largely unexplored. Here, we engineered biomimetic and estrogenic nanofiber wound dressings built from soy protein isolate (SPI) and hyaluronic acid (HA) using immersion rotary jet spinning. These engineered scaffolds were shown to successfully recapitulate the native dermal architecture, while delivering an ER-β-triggering phytoestrogen (genistein). When tested in ovariectomized mouse and ex vivo human skin tissues, HA/SPI scaffolds outperformed controls (no treatment or HA only scaffolds) towards promoting cutaneous tissue repair. These improved healing outcomes were prevented when the ER-β pathway was genetically or chemically inhibited. Our findings suggest that estrogenic fibrous scaffolds facilitate skin repair by ER-β activation.

Involvement of miRNA203 in the proliferation of epidermal stem cells during the process of DM chronic wound healing through Wnt signal pathways

BACKGROUND

The biological role of miR-203 and the underlying mechanisms on the proliferation of epidermal stem cells (ESCs) have not yet been reported during the progression of chronic wound healing in diabetes mellitus. Our previous studies have observed that the expression of miR-203 showed a marked upregulation and ESC proliferation capacity was impaired in diabetes mellitus skin wounds in rats.

METHODS

Wound models were established in normal rats and rats with type 2 diabetes. Expression level of miR-203 and the alteration of ESCs' number and function were detected. ESCs were isolated from the back skin of fetal rats to assess the effects of glucose in vitro. An antagomir to miR-203 was used to assess its effect on ESCs. Using microarray analysis, we further identified potential target genes and signaling pathways of miR-203.

RESULTS

We found that high glucose significantly upregulated the expression of miR-203 and subsequently reduced the number of ESCs and impaired their proliferation capacity. Meanwhile, over-expression of miR-203 reduced the ESCs' numbers and impaired the proliferation capacity via downregulation of the Notch and Wnt signaling pathways. Conversely, inhibition of miR-203 enhanced the proliferation capacity. Additionally, silencing miR-203 in skin of rats with type 2 diabetes accelerated wound healing and improved healing quality via the upregulation of the Notch and Wnt signaling pathways. Finally, over-expression of miR-203 downregulated genes ROCK2, MAPK8, MAPK9, and PRKCA.

CONCLUSION

Our findings demonstrated that induced expression of miR-203 by high glucose in type 2 diabetic rats decreased the number of ESCs and impaired ESC proliferation capacity via downregulating genes related to Notch and Wnt signaling pathways, resulting in a delayed wound healing.

Soy Isoflavones Inhibit Endothelial Cell Dysfunction and Prevent Cardiovascular Disease

Soybeans are among the most popular foods worldwide, and intake of soy-containing foods has been associated with many health benefits in part because of it structure similar to estrogen. Epidemiologic studies have demonstrated that soy consumption improves serum profiles of hypercholesterolemic patients. Several studies have also indicated an inverse relationship between the consumption of soy isoflavones and the incidence of cardiovascular diseases (CVD). Soy is a rich dietary source of isoflavones. The main soy isoflavones are daidzein and genistein; equol, another isoflavone and a major intestinal bacterial metabolite of daidzein, is generated by enterobacterial effects. Many isoflavones have antioxidative effects and anti-inflammatory actions, as well as induce nitric oxide production to maintain a healthy endothelium and prevent endothelial cell dysfunction. These effects may limit the development of atherosclerosis and CVD and restore healthy endothelial function in altered endothelia. Although the evidence supporting the benefits of soy isoflavones in CVD prevention continues to increase, the association between soy isoflavones and disease is not fully understood. This review summarized recent progress in identifying the preventive mechanisms of action of dietary soybean isoflavones on vascular endothelial cells. Furthermore, it describes the beneficial roles that these isoflavones may have on endothelial dysfunction-related atherosclerosis.

Systematic review and meta-analysis of mouse models of diabetes-associated ulcers

Mouse models are frequently used to study diabetes-associated ulcers, however, whether these models accurately simulate impaired wound healing has not been thoroughly investigated. This systematic review aimed to determine whether wound healing is impaired in mouse models of diabetes and assess the quality of the past research. A systematic literature search was performed of publicly available databases to identify original articles examining wound healing in mouse models of diabetes. A meta-analysis was performed to examine the effect of diabetes on wound healing rate using random effect models. A meta-regression was performed to examine the effect of diabetes duration on wound healing impairment. The quality of the included studies was also assessed using two newly developed tools. 77 studies using eight different models of diabetes within 678 non-diabetic and 720 diabetic mice were included. Meta-analysis showed that wound healing was impaired in all eight models. Meta-regression suggested that longer duration of diabetes prior to wound induction was correlated with greater degree of wound healing impairment. Pairwise comparisons suggested that non-obese diabetic mice exhibited more severe wound healing impairment compared with db/db mice, streptozotocin-induced diabetic mice or high-fat fed mice at an intermediate stage of wound healing (p<0.01). Quality assessment suggested that the prior research frequently lacked incorporation of key clinically relevant characteristics. This systematic review suggested that impaired wound healing can be simulated in many different mouse models of diabetes but these require further refinement to become more clinically relevant.

Bee Products in Dermatology and Skin Care

Honey, propolis, bee pollen, bee bread, royal jelly, beeswax and bee venom are natural products which have been used in medicine since ancient times. Nowadays, studies indicate that natural bee products can be used for skin treatment and care. Biological properties of these products are related to flavonoids they contain like: chrysin, apigenin, kaempferol, quercetin, galangin, pinocembrin or naringenin. Several pharmacological activities of phenolic acids and flavonoids, and also 10-hydroxy-trans-2-decenoic acid, which is present in royal jelly, have been reported. Royal jelly has multitude of pharmacological activities: antibiotic, antiinflammatory, antiallergenic, tonic and antiaging. Honey, propolis and pollen are used to heal burn wounds, and they possess numerous functional properties such as: antibacterial, anti-inflammatory, antioxidant, disinfectant, antifungal and antiviral. Beeswax is used for production of cosmetics and ointments in pharmacy. Due to a large number of biological activities, bee products could be considered as important ingredients in medicines and cosmetics applied to skin.

The effect of a hydrolyzed collagen-based supplement on wound healing in patients with burn: A randomized double-blind pilot clinical trial

INTRODUCTION

Burn is among the most severe forms of critical illness, associated with extensive and prolonged physical, metabolic and mental disorders. The aim of this study was to assess the effect of an oral, low-cost, and accessible collagen-based supplement on wound healing in patients with burn.

METHODS

In this randomized double-blind controlled pilot clinical trial, 31 men, 18-60years, with 20-30% total body surface area burn were studied. Patients were randomly assigned to receive either a collagen-based supplement (1000kcal) or an isocaloric placebo, for 4 weeks. Serum pre-albumin, rate of wound healing, length of hospital stay, and anthropometries were assessed at baseline, and the end of week 2 and 4.

RESULTS

Serum pre-albumin was significantly higher at week 2 (29.7±13.6 vs. 17.8±7.5mg/dL, P=0.006) and week 4 (35.1±7.6 vs. 28.3±8.2mg/dL, P=0.023) in collagen than control group. Changes in pre-albumin concentration were also significantly higher in collagen group at week 2 (13.9±9.8 vs. -1.9±10.3mg/dL, P<0.001) and week 4 (19.2±7.5 vs. 8.5±10.1mg/dL, P=0.002). The Hazard ratio of wound healing was 3.7 times in collagen compared to control group (95% CI: 1.434-9.519, P=0.007). Hospital stay was clinically, but not statistically, lower in collagen than control group (9.4±4.6 vs. 13.5±7 days, P=0.063). There were no significant differences in weight, body mass index, dietary energy and protein intakes between the two groups.

CONCLUSION

The findings showed that a hydrolyzed collagen-based supplement could significantly improve wound healing and circulating pre-albumin, and clinically reduce hospital stay in patients with 20-30% burn.

3D-printable self-healing and mechanically reinforced hydrogels with host-guest non-covalent interactions integrated into covalently linked networks

Natural polymer hydrogels are one of the best biomaterials for soft tissue repair because of their excellent biocompatibility, biodegradability and low immune rejection. However, they lack mechanical strength matching that of natural tissue and desired functionality (e.g. self-healing and 3D-printability). To solve this problem, we developed a host-guest supramolecule (HGSM) with three arms covalently crosslinked with a natural polymer to construct a novel hydrogel with non-covalent bonds integrated in a covalently crosslinked network. The unique structure enabled the hydrogel to bear improved mechanical properties and show both self-healing and 3D printing capabilities. The three-armed HGSM was first prepared via the efficient non-covalent host-guest inclusion interactions between isocyanatoethyl acrylate-modified β-cyclodextrin (β-CD-AOI2) and acryloylated tetra-ethylene glycol-modified adamantane (A-TEG-Ad). Subsequently, a host-guest supramolecular hydrogel (HGGelMA) was obtained through copolymerization between the arms of HGSM and gelatin methacryloyl (GelMA) to form a covalently crosslinked network. The HGGelMA was robust, fatigue resistant, reproducible and rapidly self-healing. In HGGelMA, the covalent crosslinking maintained its overall shape whereas the weak reversible non-covalent host-guest interactions reinforced its mechanical properties and enabled it to rapidly self-heal upon fracturing. The reversible non-covalent interactions could be re-established upon breaking, so as to heal the hydrogel and dissipate energy to prevent catastrophic fracture propagation. Furthermore, the precursors of the HGGelMA were sufficiently viscous and could be rapidly photocrosslinked to produce a robust scaffold with an exquisite internal structure through 3D printing. The 3D-printed HGGelMA hydrogel scaffold was biocompatible, promoted cell adhesion and proliferation, and supported tissue in-growth. Our strategy of integrating non-covalently linked HGSM in a covalently linked hydrogel network represents a new approach to the development of natural polymers into biocompatible hydrogels with improved strength as well as desired self-healing and 3D-printability.

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.

Genistein can ameliorate hepatic inflammatory reaction in nonalcoholic steatohepatitis rats

Genistein plays an active role in improving nonalcoholic fatty liver disease (NAFLD). This study is designed to investigate the effect of genistein on liver inflammation in rats with nonalcoholic steatohepatitis (NASH). Forty SPF male SD rats were randomly divided into normal group, model group, genistein low-dose group (0.1% wt/wt) and high-dose group (0.2% wt/wt) with 10 rats in each group. After 12 weeks' feeding, liver tissues and serum samples of rats were taken, and HE staining was used to perform pathological examination of liver tissues, then the degree of inflammatory infiltration was observed and NAFLD activity score(NAS) was calculated. With corresponding kits, several indicators were detected, namely, serum triglyceride (TG), total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), liver TC and TG, and serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), blood glucose and serum endotoxin. The levels of tumor necrosis factor (TNFα) in liver and insulin in blood of rats were detected by enzyme linked immunosorbent assay (ELISA), then the HOMA-IR index was calculated. Immunohistochemistry staining was used to observe the expression level of TLR4 protein and the RT-PCR was used to detect Tlr4 mRNA expression in liver tissue. The results showed that genistein could reduce TLR4 protein and gene expression, decrease the endotoxin and TNFα, alleviate the inflammatory reaction and make the indicators detected in blood and liver stay near normal in NASH rats. In conclusion, genistein can ameliorate hepatic inflammatory reaction in nonalcoholic steatohepatitis rats.

Effects of three flavonoids from an ancient traditional Chinese medicine Radix puerariae on geriatric diseases

As the worldwide population ages, the morbidity of neurodegenerative, cardiovascular, cerebrovascular, and endocrine diseases, such as diabetes and osteoporosis, continues to increase. The etiology of geriatric diseases is complex, involving the interaction of genes and the environment, which makes effective treatment challenging. Traditional Chinese medicine, unlike Western medicine, uses diverse bioactive ingredients to target multiple signaling pathways in geriatric diseases. Radix puerariae is one of the most widely used ancient traditional Chinese medicines and is also consumed as food. This review summarizes the evidence from in vivo and in vitro studies of the pharmacological effects of the main active components of the tuber of Radix puerariae on geriatric diseases.

Soy Protein/Cellulose Nanofiber Scaffolds Mimicking Skin Extracellular Matrix for Enhanced Wound Healing

Historically, soy protein and extracts have been used extensively in foods due to their high protein and mineral content. More recently, soy protein has received attention for a variety of its potential health benefits, including enhanced skin regeneration. It has been reported that soy protein possesses bioactive molecules similar to extracellular matrix (ECM) proteins and estrogen. In wound healing, oral and topical soy has been heralded as a safe and cost-effective alternative to animal protein and endogenous estrogen. However, engineering soy protein-based fibrous dressings, while recapitulating ECM microenvironment and maintaining a moist environment, remains a challenge. Here, the development of an entirely plant-based nanofibrous dressing comprised of cellulose acetate (CA) and soy protein hydrolysate (SPH) using rotary jet spinning is described. The spun nanofibers successfully mimic physicochemical properties of the native skin ECM and exhibit a high water retaining capability. In vitro, CA/SPH nanofibers promote fibroblast proliferation, migration, infiltration, and integrin β1 expression. In vivo, CA/SPH scaffolds accelerate re-epithelialization and epidermal thinning as well as reduce scar formation and collagen anisotropy in a similar fashion to other fibrous scaffolds, but without the use of animal proteins or synthetic polymers. These results affirm the potential of CA/SPH nanofibers as a novel wound dressing.

MiR-181c restrains nitration stress of endothelial cells in diabetic db/db mice through inhibiting the expression of FoxO1

Endothelial dysfunction played an important role in the progression of diabetes mellitus (DM). miR-181c has been implicated in many diseases, including DM. However, the molecular mechanisms of miR-181c regulate this process remained poorly understood. Healthy ICR mice were divided into control group (n = 10) and db/db DM group (n = 10). The expression of miR-181c and FoxO1 were both investigated in diabetic db/db mice or high glucose-induced endothelial cells (MAECs and END-D). Here we found that down-regulation of miR-181c and the activation of FoxO1/iNOS were observed in mice and endothelial cells. Furthermore, we verified that miR-181c directly targeted and inhibited FoxO1 gene expression by targeting its 3'-UTR through luciferase reporter assay. Knockdown of FoxO1 reversed the up-regulation of iNOS, nitrotyrosine and the down-regulation of p-eNOS^Ser1177/eNOS in high glucose (30 mM)-induced MAECs cells. In addition, over-expression of miR-181c could reverse the enhanced nitration stress induced by high glucose, while this effect could be attenuated by pcDNA-FoxO1 in MAECs. These results shown that miR-181c attenuated nitration stress through regulating FoxO1 expression and affecting endothelial cell function, which offering a new target for the development of preventive or therapeutic agents against DM.

Downregulation of B-myb promotes senescence via the ROS-mediated p53/p21 pathway, in vascular endothelial cells

OBJECTIVES

To reveal whether B-myb is involved in preventing senescence of vascular endothelial cells, and if so, to identify possible mechanisms for it.

MATERIALS AND METHODS

C57/BL6 male mice and primary human aortic endothelial cells (HAECs) were used. Bleomycin was applied to induce stress-related premature senescence. B-myb knockdown was achieved using an siRNA technique and cell senescence was assessed using the senescence-associated β-galactosidase (SA-β-gal) assay. Intracellular reactive oxygen species (ROS) production was analysed using an ROS assay kit and cell proliferation was evaluated using KFluor488 EdU kit. Capillary tube network formation was determined by Matrigel assay. Expressions of mRNA and protein levels were detected by real-time PCR and western blotting.

RESULTS

B-myb expression significantly decreased, while p53 and p21 expressions increased in the aortas of aged mice. This expression pattern was also found in replicative senescent HAECs and senescent HAECs induced by bleomycin. B-myb knockdown resulted in upregulation of p22^phox , ROS accumulation and cell senescence of HAECs. Downregulation of B-myb significantly inhibited cell proliferation and capillary tube network formation and activated the p53/p21 signalling pathway. Blocking ROS production or inhibiting p53 activation remarkably attenuated SA-β-gal activity and delayed cell senescence induced by B-myb-silencing.

CONCLUSION

Downregulation of B-myb induced senescence by upregulation of p22^phox and activation of the ROS/p53/p21 pathway, in our vascular endothelial cells, suggesting that B-myb may be a novel candidate for regulating cell senescence to protect against endothelial senescence-related cardiovascular diseases.

Isoflavones: Anti-Inflammatory Benefit and Possible Caveats

Inflammation, a biological response of body tissues to harmful stimuli, is also known to be involved in a host of diseases, such as obesity, atherosclerosis, rheumatoid arthritis, and even cancer. Isoflavones are a class of flavonoids that exhibit antioxidant, anticancer, antimicrobial, and anti-inflammatory properties. Increasing evidence has highlighted the potential for isoflavones to prevent the chronic diseases in which inflammation plays a key role, though the underlying mechanisms remain unclear. Recently, some studies have raised concerns about isoflavones induced negative effects like carcinogenesis, thymic involution, and immunosuppression. Therefore, this review aims to summarize the anti-inflammatory effects of isoflavones, unravel the underlying mechanisms, and present the potential health risks.

Genistein supplementation prevents weight gain but promotes oxidative stress and inflammation in the vasculature of female obese ob/ob mice

Obesity, a state of chronic low-grade inflammation, is strongly associated with the development of hypertension and diabetes. Superoxide, a free radical elevated in obese individuals, promotes hypertension through scavenging the endogenous vasodilator nitric oxide. The hypothesis was a genistein-enriched diet would promote weight loss and reduce oxidative stress and inflammation in the vasculature of intact female ob/ob mice. Aortas and mesenteric arteries were isolated from female ob/ob mice fed genistein-free (0mg genistein/kg diet; n=6), standard chow (200-300mg genistein/kg diet; n=11) or genistein-enriched (600mg genistein/kg diet; n=9) diets for 4weeks. Sections of isolated vessels were labeled with the superoxide indicator dihydroethidium and fluorescence was measured by confocal microscopy. Protein expression of the inflammatory marker inducible nitric oxide synthase (iNOS) was measured in the perivascular adipose tissue (PVAT) surrounding each vessel and plasma concentrations of superoxide dismutase (SOD) were quantified. Genistein-enriched diet promoted less weight gain compared to animals fed standard chow (P=.008). Standard chow promoted increased superoxide in the aorta (P=.030) and mesenteric arteries (P=.024) compared to a diet devoid of genistein. At all tested concentrations, genistein significantly increased iNOS expression in mesenteric artery PVAT (vs. standard chow, P<.001; vs. genistein-enriched, P=.002) and tended to increase iNOS within the aortic PVAT (standard chow, P=.075) compared to the genistein-free group. Plasma SOD activity was significantly downregulated in genistein-enriched animals as compared to those fed a genistein-free diet (P=.028). In summary, although genistein prevents weight gain, it promotes vascular oxidative stress and inflammation in obese ovarian-intact female mice.

Oestrogen promotes healing in a bacterial LPS model of delayed cutaneous wound repair

Wound infection is a major clinical problem, yet understanding of bacterial host interactions in the skin remains limited. Microbe-derived molecules, known as pathogen-associated molecular patterns, are recognised in barrier tissues by pattern-recognition receptors. In particular, the pathogen-associated molecular pattern, lipopolysaccharide (LPS), a component of microbial cell walls and a specific ligand for Toll-like receptor 4, has been widely used to mimic systemic and local infection across a range of tissues. Here we administered LPS derived from Klebsiella pneumoniae, a species of bacteria that is emerging as a wound-associated pathogen, to full-thickness cutaneous wounds in C57/BL6 mice. Early in healing, LPS-treated wounds displayed increased local apoptosis and reduced proliferation. Subsequent healing progression was delayed with reduced re-epithelialisation, increased proliferation, a heightened inflammatory response and perturbed wound matrix deposition. Our group and others have previously demonstrated the beneficial effects of 17β-estradiol treatment across a range of preclinical wound models. Here we asked whether oestrogen would effectively promote healing in our LPS bacterial infection model. Intriguingly, co-treatment with 17β-estradiol was able to promote re-epithelialisation, dampen inflammation and induce collagen deposition in our LPS-delayed healing model. Collectively, these studies validate K. pneumoniae-derived LPS treatment as a simple yet effective model of bacterial wound infection, while providing the first indication that oestrogen could promote cutaneous healing in the presence of infection, further strengthening the case for its therapeutic use.

Antidiabetic properties of dietary flavonoids: a cellular mechanism review

Background

Natural food products have been used for combating human diseases for thousands of years. Naturally occurring flavonoids including flavones, flavonols, flavanones, flavonols, isoflavones and anthocyanidins have been proposed as effective supplements for management and prevention of diabetes and its long-term complications based on in vitro and animal models.

Aim

To summarize the roles of dietary flavonoids in diabetes management and their molecular mechanisms.

Findings

Tremendous studies have found that flavonoids originated from foods could improve glucose metabolism, lipid profile, regulating the hormones and enzymes in human body, further protecting human being from diseases like obesity, diabetes and their complications.

Conclusion

In the current review, we summarize recent progress in understanding the biological action, mechanism and therapeutic potential of the dietary flavonoids and its subsequent clinical outcomes in the field of drug discovery in management of diabetes mellitus.