Altered molecular mechanisms of diabetic foot ulcers

Comparing collagenase and silver sulfadiazine in deep second-degree burn treatment

The indications for collagenase ointment (CO) and its efficacy are not clearly established in the treatment of second-degree burn wounds. To evaluate the efficacy of CO versus silver sulfadiazine ointment (SSD) in the treatment of second-degree burn wounds. A total of 170 eligible patients with deep second-degree burns, aged 18-65 years, with injuries occurring within 48-96 h, and having a total wound area of less than 30% of the total body surface area were included from 5 centers in China. The primary outcome was the wound healing time, and the secondary outcomes were the clearance time of wound necrotic tissues, wound healing rate, and wound inflammation. The study included 85 patients in SSD group and 84 in CO group in the modified intention-to-treat (mITT) population. The median time of wound healing was comparable in both groups (10 days vs. 10.5 days P = 0.16). The time for wound necrotic tissue removal was significantly shortened by CO compared with SSD (5 vs. 10 days P < 0.01). Wound inflammation, pain, wound healing rate, and scar were compared with SSD (all P-values > 0.05). No adverse events, such as infection or allergic reactions to the drugs and materials used, were reported. Both CO and SSD could heal the burn wounds at 10 days of treatment. However, CO significantly shortened the time of wound necrotic tissue removal by 5 days. Trial Registration: ChiCTR2100046971.

Design Strategy of Microneedle Systems for Skin Wound Healing: Based on the Structure of Tips and Therapeutic Methodologies

The skin, being the largest organ of the human body, is susceptible to damage resulting in wounds that are vulnerable to pathogenic attacks and fail to provide effective protection for internal tissues. Therefore, it is crucial to expedite wound healing. In recent years, microneedles have garnered significant attention as an innovative drug delivery system owing to their noninvasive and painless administration, simplified application process, precise control over drug release, and versatile loading capabilities. Consequently, they hold immense potential for the treatment of skin wound. This review presents a comprehensive design strategy for the microneedle system in promoting skin wound healing. First, the process of skin wound healing and the characteristics of specific wounds are elucidated. The design strategies for microneedles are subsequently presented and classified based on their structural and therapeutic methodologies. Finally, a succinct recapitulation of the previously discussed points and a prospective analysis are provided.

Injectable and Microporous Microgel-Fiber Granular Hydrogel Loaded with Bioglass and siRNA for Promoting Diabetic Wound Healing

Injectable hydrogels find extensive application in the treatment of diabetic wound healing. However, traditional bulk hydrogels are significantly limited due to their nano-porous structure, which obstructs cell migration and tissue infiltration. Moreover, regulating inflammation and matrix metalloproteinase -9 (MMP-9) expression in diabetic wounds is crucial for enhancing wound healing. This study marks the first instance of introducing an efficient, scalable, and simple method for producing microfiber-gel granules encapsulating bioceramics powders. Utilizing this method, an injectable microporous granular microgel-fiber hydrogel (MFgel) is successfully developed by assembling microgel-fibers made from hyaluronic acid (HA) and sodium alginate (SA) loaded with small interfering RNA (siRNA) and bioglass (BG) particles. Compared to traditional hydrogels (Tgel), MFgel possesses a highly interconnected network with micron-sized pores, demonstrating favorable properties for cell adhesion and penetration in in vitro experiments. Additionally, MFgel exhibits a higher compressive modulus and superior mechanical stability. When implanted subcutaneously in mice, MFgel promotes cellular and tissue infiltration, facilitating cell proliferation. Furthermore, when applied to skin defects in diabetic rats, MFgel not only effectively regulates inflammation and suppresses MMP-9 expression but also enhances angiogenesis and collagen deposition, thereby significantly accelerating diabetic wound healing. Taken together, this hydrogel possesses great potential in diabetic wound healing applications.

Randomized Double-blind Cost-effectiveness Comparison of Two 10% Urea Creams in Patients with Diabetic Foot Syndrome

OBJECTIVE

To evaluate the cost-effectiveness of two 10% urea creams in patients with diabetic foot syndrome.

METHODS

This was a prospective, longitudinal, single-center, randomized, double-blind, prospective clinical trial that evaluated the skin quality of 20 feet belonging to 10 patients with diabetic foot syndrome after the application of two 10% urea creams purchased from pharmacies and supermarkets.

RESULTS

At follow-up, 19 (95%) of the participants' feet showed improved skin quality, irrespective of the cream applied. On visual inspection, participants had a decreased presence of xerosis, hyperkeratosis, and preulcerative signs such as subkeratotic bruising and areas of redness on the dorsum of the toes. At the 3-month follow-up, nine (90%) of the participants stated that they had continued to apply the cream as a method of self-management to prevent complications.

CONCLUSIONS

Creams containing 10% urea purchased in supermarkets improve foot skin quality in patients with diabetic foot syndrome, regardless of their cost. Based on these findings, the authors recommend creams containing 10% urea as a self-management tool for patients with diabetic foot syndrome.

Short-Term l-arginine Treatment Mitigates Early Damage of Dermal Collagen Induced by Diabetes

Changes in the structural properties of the skin due to collagen alterations are an important factor in diabetic skin complications. Using a combination of photonic methods as an optic diagnostic tool, we investigated the structural alteration in rat dermal collagen I in diabetes, and after short-term l-arginine treatment. The multiplex approach shows that in the early phase of diabetes, collagen fibers are partially damaged, resulting in the heterogeneity of fibers, e.g., "patchy patterns" of highly ordered/disordered fibers, while l-arginine treatment counteracts to some extent the conformational changes in collagen-induced by diabetes and mitigates the damage. Raman spectroscopy shows intense collagen conformational changes via amides I and II in diabetes, suggesting that diabetes-induced structural changes in collagen originate predominantly from individual collagen molecules rather than supramolecular structures. There is a clear increase in the amounts of newly synthesized proline and hydroxyproline after treatment with l-arginine, reflecting the changed collagen content. This suggests that it might be useful for treating and stopping collagen damage early on in diabetic skin. Our results demonstrate that l-arginine attenuates the early collagen I alteration caused by diabetes and that it could be used to treat and prevent collagen damage in diabetic skin at a very early stage.

3D Printing of Alginate/Chitosan-Based Scaffold Empowered by Tyrosol-Loaded Niosome for Wound Healing Applications: In Vitro and In Vivo Performances

This study introduces a tyrosol-loaded niosome integrated into a chitosan-alginate scaffold (Nio-Tyro@CS-AL), employing advanced electrospinning and 3D printing techniques for wound healing applications. The niosomes, measuring 185.40 ± 6.40 nm with a polydispersity index of 0.168 ± 0.012, encapsulated tyrosol with an efficiency of 77.54 ± 1.25%. The scaffold's microsized porous structure (600-900 μm) enhances water absorption, promoting cell adhesion, migration, and proliferation. Mechanical property assessments revealed the scaffold's enhanced resilience, with niosomes increasing the compressive strength, modulus, and strain to failure, indicative of its suitability for wound healing. Controlled tyrosol release was demonstrated in vitro, essential for therapeutic efficacy. The scaffold exhibited significant antibacterial activity against Pseudomonas aeruginosa and Staphylococcus aureus, with substantial biofilm inhibition and downregulation of bacterial genes (ndvb and icab). A wound healing assay highlighted a notable increase in MMP-2 and MMP-9 mRNA expression and the wound closure area (69.35 ± 2.21%) in HFF cells treated with Nio-Tyro@CS-AL. In vivo studies in mice confirmed the scaffold's biocompatibility, showing no significant inflammatory response, hypertrophic scarring, or foreign body reaction. Histological evaluations revealed increased fibroblast and macrophage activity, enhanced re-epithelialization, and angiogenesis in wounds treated with Nio-Tyro@CS-AL, indicating effective tissue integration and repair. Overall, the Nio-Tyro@CS-AL scaffold presents a significant advancement in wound-healing materials, combining antibacterial properties with enhanced tissue regeneration, and holds promising potential for clinical applications in wound management.

Fibroblasts in Diabetic Foot Ulcers

Fibroblasts are stromal cells ubiquitously distributed in the body of nearly every organ tissue. These cells were previously considered to be "passive cells", solely responsible for ensuring the turnover of the extracellular matrix (ECM). However, their versatility, including their ability to switch phenotypes in response to tissue injury and dynamic activity in the maintenance of tissue specific homeostasis and integrity have been recently revealed by the innovation of technological tools such as genetically modified mouse models and single cell analysis. These highly plastic and heterogeneous cells equipped with multifaceted functions including the regulation of angiogenesis, inflammation as well as their innate stemness characteristics, play a central role in the delicately regulated process of wound healing. Fibroblast dysregulation underlies many chronic conditions, including cardiovascular diseases, cancer, inflammatory diseases, and diabetes mellitus (DM), which represent the current major causes of morbidity and mortality worldwide. Diabetic foot ulcer (DFU), one of the most severe complications of DM affects 40 to 60 million people. Chronic non-healing DFU wounds expose patients to substantial sequelae including infections, gangrene, amputation, and death. A complete understanding of the pathophysiology of DFU and targeting pathways involved in the dysregulation of fibroblasts are required for the development of innovative new therapeutic treatments, critically needed for these patients.

The Intersection of Dermatological Dilemmas and Endocrinological Complexities: Understanding Necrobiosis Lipoidica-A Comprehensive Review

BACKGROUND

Necrobiosis lipoidica (NL) is a rare granulomatous skin disorder with a predilection for females, often associated with diabetes mellitus (DM). This paper aims to comprehensively review the literature on NL, focusing on its association with DM, thyroid disorders, and the metabolic syndrome.

METHODS

A systematic search was conducted in English-language literature from inception to October 2023, utilizing PubMed. We identified 530 studies and selected 19 based on clinical significance, statistical support, and relevance to the paper's goals.

RESULTS

The coexistence of NL and DM is prevalent, with rates ranging from 11% to 65.71%. NL may precede DM diagnosis and a correlation between NL and increased daily insulin requirements has been observed in such patients. NL is suggested as a potential prognostic marker for DM complications; however, recent studies question this association, highlighting the need for further research. Studies in the context of NL and Thyroid Disease indicate a correlation, especially with autoimmune thyroiditis. Regarding NL and Metabolic Syndrome, the prevalence of metabolic syndrome among NL patients is notably higher than in the general population. Additionally, DM patients with ulcerated NL commonly exhibit hypertension or obesity, raising questions about the potential influence of hypertension and obesity on NL ulcerations.

CONCLUSION

Additional research is required to untangle the complex connections between NL and various comorbidities.

Electrospun membranes chelated by metal magnesium ions enhance pro-angiogenic activity and promote diabetic wound healing

Diabetic wounds, resulting from skin atrophy due to localized ischemia and hypoxia in diabetic patients, lead to chronic pathological inflammation and delayed healing. Using electrospinning technology, we developed magnesium ion-chelated nanofiber membranes to explore their efficacy in antibacterial, anti-inflammatory, and angiogenic applications for wound healing. These membranes are flexible and elastic, resembling native skin tissue, and possess good hydrophilicity for comfortable wound bed contact. The mechanical properties of nanofiber membranes are enhanced by the chelation of magnesium ions (Mg2+), which also facilitates a long-term slow release of Mg2+. The cytocompatibility of the nanofibrous membranes is influenced by their Mg2+ content: lower levels encourage the proliferation of fibroblasts, endothelial cells, and macrophages, while higher levels are inhibitory. In a diabetic rat model, magnesium ion-chelated nanofibrous membranes effectively reduced early wound inflammation and notably accelerated wound healing. This study highlights the potential of magnesium ion-chelated nanofiber membranes in treating diabetic wounds.

Stem Cell-Based Tissue Engineering Approaches for Diabetic Foot Ulcer: a Review from Mechanism to Clinical Trial

Diabetic foot ulcer (DFU) is a complication from incomplete or prolonged wound healing, at times requires amputation, putting substantial health and socioeconomic burden. Wound healing is a dynamic overlapping process that can be regulated by arrays of molecular factors showing redundancy in function. However, dysregulation in the mechanism of angiogenesis, extra cellular matrix (ECM) formation and immune modulation are the major causes for impair wound healing in hyperglycaemic patients. Despite development of wound care research, there is a lack of well-accepted targeted therapy with multidisciplinary approach for DFU treatment. Stem cell therapy holds a promising outcome both in preclinical and clinical trials because of its ability to promote healing via regeneration and specialized tissue differentiation. Among different types of stem cells, regenerative potential of mesenchymal stem cell (MSC) is well demonstrated in both experimental and clinical trial. Still there is a huge knowledge gap among medical practitioners for deciding the best stem cell source, administration route, and safety. This review strengthens the fact that why stem cell therapy is a promising candidate to treat DFU and cited multiple tissue engineering and biomaterial-based approaches for delivering stem cells and their aftermath paracrine events. Based on the pre-clinical and clinical studies, the review tried to come up with optimum stem cell source and delivery route for the treatment of DFU. At last, the review glances on possible direction to enhance therapeutics strategy for the same, including different approaches like: phytocompounds, exosomes, scaffold geometry, cell preconditioning and licensing etc.

Traditional complementary and alternative medicine (TCAM) for diabetic foot ulcer management: A systematic review

Diabetic Foot Ulcers (DFUs) are a devastating micro-vascular complication of diabetes with an increased prevalence and incidence and high rate of morbidity and mortality. Since antibiotics are frequently used to treat DFU, managing the condition has proven to be extremely challenging and may eventually lead to the development of antibiotic resistance. Scientists from around the world are working to develop an alternative solution to the problem of drug resistance by exploring complementary and alternative medicines that may be obtained from natural sources. Hence, the review aims to comprehensively report the information on the natural treatments and therapy used to manage DFU. All of the information described in the current study was gathered from electronic scientific resources, including Google Scholar, PubMed, Scopus, Science Direct, and Springer Link. Findings from the current review revealed the pre-clinical and clinical utility of 18 medicinal plants, 1 isolated compound, 7 polyherbal formulations including herbal creams, a few micronutrients including vitamins and minerals, insect products such as propolis, honey and, Maggot debridement therapy for the treatment and management of DFU. Natural therapies possess better efficacy, low cost, and shorter duration of treatment when compared with the conventional treatments; hence, all information made available about them is crucial to alter the direction of treatment. Furthermore, the data presented in this review are up to date on the potential efficacy of natural complementary medicines for alleviating DFU problems in in vitro and in vivo tests, as well as clinical studies.

Therapeutic role of growth factors in treating diabetic wound

Wounds in diabetic patients, especially diabetic foot ulcers, are more difficult to heal compared with normal wounds and can easily deteriorate, leading to amputation. Common treatments cannot heal diabetic wounds or control their many complications. Growth factors are found to play important roles in regulating complex diabetic wound healing. Different growth factors such as transforming growth factor beta 1, insulin-like growth factor, and vascular endothelial growth factor play different roles in diabetic wound healing. This implies that a therapeutic modality modulating different growth factors to suit wound healing can significantly improve the treatment of diabetic wounds. Further, some current treatments have been shown to promote the healing of diabetic wounds by modulating specific growth factors. The purpose of this study was to discuss the role played by each growth factor in therapeutic approaches so as to stimulate further therapeutic thinking.

Egg yolk oil accelerates wound healing in streptozotocin induced diabetic rats

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

Advances in wound repair and regeneration: Systematic comparison of cell free fat extract and platelet rich plasma

Background: Previous studies showed Cell free fat extract (CEFFE) and Platelet rich plasma (PRP) could effectively accelerate wound healing. However, the comparative study on curative effect is still lacking. A systematic comparison could provide more theoretical support and laboratory basis for the clinical application of CEFFE and PRP. Objective: To compare the efficacy of CEFFE and PRP in promoting skin wound repair. Methods: CEFFE and PRP were prepared according to the literature. The wound repair related factors were measured and compared. In vitro, the effects of both on cell migration, proliferation and tube formation were compared. In vivo, wound healing rate was measured on the 1st, 3rd, 9th, and 12th days after skin injury and treatment. Then the specimens were cut off for histological analysis. Results: Although the total protein content of PRP was significantly around 19 times higher than that of CEFFE, there was no statistical difference in the content of BDNF, EGF and VEGF between CEFFE and PRP. Even the NT-3 content of CEFFE was just slightly higher than that of PRP. The concentration of b-FGF, HGF and TGF-β and PDGF-BB in PRP is higher than that in CEFFE, but there is only a very small difference between them. In vitro, PRP showed better efficacy than CEFFE in promoting fibroblast proliferation while there was no significant difference in promoting angiogenesis and fibroblast migration. Both PRP and CEFFE could significantly promote wound healing in mice. There was no statistical difference in wound healing between CEFFE and PRP groups in vivo. Immunohistochemical staining of Ki67&CD31 showed that there was no significant difference between PRP and CEFFE groups. Conclusion: The effect of PRP and CEFFE in promoting wound healing was similar. In clinical practice, the acquisition of PRP is relatively more convenient. Containing no cells, CEFFE has the advantage of easier preservation. For patients who have discarded adipose tissue, or contraindications to PRP technology, CEFFE technology may provide a new option for skin wound repair.

Fibronectin in hyperglycaemia and its potential use in the treatment of diabetic foot ulcers: A review

Metabolism of fibronectin, the protein that plays a key role in the healing of wounds, is changed in the patients with diabetes mellitus. Fibronectin can interact with other proteins and proteoglycans and organise them to form the extracellular matrix, the basis of the granulation tissue in healing wounds. However, diabetic foot ulcers (DFUs) suffer from inadequate deposition of this protein. Degradation prevails over fibronectin synthesis in the proteolytic inflammatory environment in the ulcers. Because of the lack of fibronectin in the wound bed, the assembly of the extracellular matrix and the deposition of the granulation tissue cannot be started. A number of methods have been designed that prevents fibronectin degradation, replace lacking fibronectin or support its formation in non-healing wounds in animal models of diabetes. The aim of this article is to review the metabolism of fibronectin in DFUs and to emphasise that it would be useful to pay more attention to fibronectin matrix assembly in the ulcers when laboratory methods are translated to clinical practice.

Silk Fibroin Biomaterials and Their Beneficial Role in Skin Wound Healing

The skin, acting as the outer protection of the human body, is most vulnerable to injury. Wound healing can often be impaired, leading to chronic, hard-to-heal wounds. For this reason, searching for the most effective dressings that can significantly enhance the wound healing process is necessary. In this regard, silk fibroin, a protein derived from silk fibres that has excellent properties, is noteworthy. Silk fibroin is highly biocompatible and biodegradable. It can easily make various dressings, which can be loaded with additional substances to improve healing. Dressings based on silk fibroin have anti-inflammatory, pro-angiogenic properties and significantly accelerate skin wound healing, even compared to commercially available wound dressings. Animal studies confirm the beneficial influence of silk fibroin in wound healing. Clinical research focusing on fibroin dressings is also promising. These properties make silk fibroin a remarkable natural material for creating innovative, simple, and effective dressings for skin wound healing. In this review, we summarise the application of silk fibroin biomaterials as wound dressings in full-thickness, burn, and diabetic wounds in preclinical and clinical settings.

Negative Pressure Wound Therapy Promotes Wound Healing by Inhibiting Inflammation in Diabetic Foot Wounds: A Role for NOD1 Receptor

Aims: Diabetic foot results in frequent amputation and quality-of-life reduction in diabetes population. These lesions are featured by a prolonged and exaggerated inflammation with a significant impairment in local bacterial invasion. Negative pressure wound therapy (NPWT) attenuates hyperinflammation in the healing of diabetic foot wounds, but the potential mechanism of NPWT down-regulated inflammatory reaction still remains elusive. This study aims to explore the inflammatory signaling involved in the effect of NPWT on diabetic ulcer. Methods: Thirty patients with diabetic foot ulceration were divided into NPWT group (treated with NPWT, n = 10), NPWT + FK565 group (treated with NPWT combined with FK565 which is NOD1 receptor ligand, n = 10) and control group (n = 10). After two weeks treatment, samples were harvested and analyzed by histochemistry for infiltration of inflammatory cells, immunofluorescence stain for NOD1, western blotting for NOD1, RIP2 (Receptor interacting protein 2), IL-1β, TAK1 (Transforming growth factor-β-activated kinase1), p65 and real time-PCR for expression of NOD1 and RIP2. Results: NPWT could notably accelerate the diabetic wound healing through alleviating inflammatory reaction. The immunofluorescence analysis results revealed that NOD1 was mainly expressed in the cytoplasm and noticeably decreased after the NPWT treatment. And NPWT obviously decreased both the mRNA and protein level of NOD1 and RIP2. Moreover, The protein expression of IL-1β, TAK1 and p65 in the NPWT-group were significant decreased. Conclusion: NPWT effectively promotes wound healing by suppressing the wound inflammation in diabetic foot, which is mediated at least in part by suppression of NOD1 receptor.

Evolving spectrum of diabetic wound: Mechanistic insights and therapeutic targets

Diabetes mellitus is a chronic metabolic disorder resulting in an increased blood glucose level and prolonged hyperglycemia, causes long term health conse-quences. Chronic wound is frequently occurring in diabetes patients due to compromised wound healing capability. Management of wounds in diabetic patients remains a clinical challenge despite many advancements in the field of science and technology. Increasing evidence indicates that alteration of the biochemical milieu resulting from alteration in inflammatory cytokines and matrix metalloproteinase, decrease in fibroblast and keratinocyte functioning, neuropathy, altered leukocyte functioning, infection, etc., plays a significant role in impaired wound healing in diabetic people. Apart from the current pharmacotherapy, different other approaches like the use of conventional drugs, antidiabetic medication, antibiotics, debridement, offloading, platelet-rich plasma, growth factor, oxygen therapy, negative pressure wound therapy, low-level laser, extracorporeal shock wave bioengineered substitute can be considered in the management of diabetic wounds. Drugs/therapeutic strategy that induce angiogenesis and collagen synthesis, inhibition of MMPs, reduction of oxidative stress, controlling hyperglycemia, increase growth factors, regulate inflammatory cytokines, cause NO induction, induce fibroblast and keratinocyte proliferation, control microbial infections are considered important in controlling diabetic wound. Further, medicinal plants and/or phytoconstituents also offer a viable alternative in the treatment of diabetic wound. The focus of the present review is to highlight the molecular and cellular mechanisms, and discuss the drug targets and treatment strategies involved in the diabetic wound.

A novel alginate from Sargassum seaweed promotes diabetic wound healing by regulating oxidative stress and angiogenesis

Diabetic skin ulcer is one of the most severe complications in diabetes, however, current therapeutic approaches are not effective enough. Agents modulating oxidative stress, inflammation, and angiogenesis are quite promising for alleviation of diabetic skin ulcers. In this study, a novel Sargassum kjellmanianum-derived polysaccharide (SARP) was prepared. SARP was an alginate with Mw of 45.4 kDa, consisting of 76.56% mannuronic acid, 18.89% guluronic acid, and 4.55% glucuronic acid. SARP could attenuate oxidative stress-induced cell damage via activating nuclear factor erythroid 2-related factor 2 (Nrf2). SARP also promoted the migration and tube formation of HUVECs, which was related to the increased vascular endothelial growth factor (VEGF) expression. In diabetic wound model, SARP (iv, 200 mg/kg) administration increased angiogenesis, alleviated oxidative stress, ameliorated diabetes-related aberrations, and thereby accelerated diabetic wound healing. These findings identified SARP had potential to be developed as a drug candidate for diabetic skin ulcers.

A hybrid hydrogel encapsulating human umbilical cord mesenchymal stem cells enhances diabetic wound healing

BACKGROUND

Diabetic wound is a severe complication of diabetes. Stem cell is considered as a promising therapy for diabetic skin wounds. Hydrogel can supply niche for cells adhesion and survival to improve the efficacy of stem cell therapy, but the development of hydrogel with suitable properties remains a great challenge. Thus, our study was conducted to combine an optimized hydrogel with stem cell to improve complex diabetic wound treatment.

METHODS

This study constructed a hydrogel with low toxicity and adjustable mechanical properties from gelatin methacrylate (GelMA) and chitosan-catechol (Chi-C), and encapsulated human umbilical cord-mesenchymal stem cells (hUMSCs) to repair full-thickness diabetic wound.

RESULTS

We explored the relationship between mechanical stiffness and cell proliferation and differentiation potency, and found 10% GelMA hydrogel with an optimal stiffness improved hUMSCs adhesion, proliferation, and differentiation potency maintenance in vitro. Assistant with optimized hydrogel encapsulating hUMSCs, diabetic wound healing process was greatly accelerated, including accelerated wound closure, inhibited secretion of inflammatory factors TNF-α and IL-1β, promoted vascular regeneration and collagen deposition after treatment of hUMSCs.

CONCLUSIONS

The optimized hydrogel encapsulating hUMSCs improved diabetic wound healing, and has a broad implication for the treatment of diabetic complication. Diabetic wound is a severe complication of diabetes. Stem cell is considered as a promising therapy for diabetic skin wounds. Hydrogel can supply niche for cells adhesion and survival to improve the efficacy of stem cell therapy. This study constructed a hydrogel with low toxicity and adjustable mechanical properties from gelatin methacrylate (GelMA) and chitosan-catechol (Chi-C), and encapsulated human umbilical cord-mesenchymal stem cells (hUMSCs) to repair full-thickness diabetic wound. Hydrogel of 10% GelMA with an optimal stiffness improved hUMSCs adhesion, proliferation, and differentiation potency maintenance in vitro. Assistant with optimized hydrogel encapsulating hUMSCs, diabetic wound healing process was greatly accelerated, including accelerated wound closure, inhibited secretion of inflammatory factors TNF-α and IL-1β, promoted vascular regeneration and collagen deposition after treatment of hUMSCs. The study supplies an alternative treatment for diabetic complication. Hydrogel-hUMSCs combined treatment accelerates wound closure in diabetic mice. A. Representative images of wounds during 21-day in vivo experiments. B. Quantification of wound closure rate (%) over 21-day period. C. HE staining of wounds at days 7, 14 and 21. The bar corresponds to 200 μm.

Effect of platelet-rich plasma vs standard management for the treatment of diabetic foot ulcer wounds: A meta-analysis

We performed a meta-analysis to evaluate the effect of platelet-rich plasma vs standard management for the treatment of diabetic foot ulcer wounds. A systematic literature search up to March 2022 was performed and 1435 subjects with diabetic foot ulcer wounds at the baseline of the studies; 723 of them were treated with platelet-rich plasma, and 712 used control. Odds ratio (OR) with 95% confidence intervals (CIs) was calculated to assess the effect of platelet-rich plasma vs standard management for the treatment of diabetic foot ulcer wounds using the dichotomous method with a random or fixed-effect model. The use of autologous platelet-rich plasma resulted in significantly higher complete-healed diabetic foot ulcer wounds compared with control (OR, 1.95; 95% CI, 1.49-2.56, P < 0.001). The use of allogeneic platelet-rich plasma resulted in significantly higher complete-healed diabetic foot ulcer wounds compared with control (OR, 6.19; 95% CI, 2.32-16.56, P < 0.001). The use of autologous and allogeneic platelet-rich plasma resulted in significantly higher complete-healed diabetic foot ulcer wounds compared with control. Though, the analysis of outcomes should be with caution because of the low number of studies in certain comparisons, for example, allogeneic platelet-rich plasma compared with control.

Improving Dietary Intake of Essential Nutrients Can Ameliorate Inflammation in Patients with Diabetic Foot Ulcers

Diabetic foot ulcers (DFUs) are classified as chronic wounds and are one of the most common complications of diabetes. In chronic wounds, management of inflammation is a key step in treatment. Nutrition plays an important role in managing and controlling inflammation. This study evaluated the effects of nutrition supplementation and education on inflammatory biomarkers in patients with DFUs. Eligible patients with foot ulcers were randomly assigned to either a treatment (n = 15) or control group (n = 14). Both groups received standard care for wound treatment from the clinic; however, the treatment group was also provided with nutritional supplementation and education. Plasma concentrations of inflammatory biomarkers, namely C-reactive protein (CRP), interleukin 6 (IL6), interleukin 10 (IL10), and tristetraprolin (TTP), were evaluated at baseline and every four weeks, until complete wound closure had occurred or up to 12 weeks. The mean plasma concentration of IL6 significantly decreased in the treatment group (p = 0.001). The interaction between time and group was not statistically significant for the mean plasma concentrations of CRP, IL10, and TTP during the 12 weeks of the study. The results of this study showed the positive effects of nutritional intervention on controlling inflammation in DFU patients. More clinical trials with a larger population and longer duration of time are needed to confirm our results.

Zizhu Ointment Accelerates Wound-Healing of Diabetic Ulcers through Promoting M2 Macrophage Polarization via Downregulating the Notch4 Signaling Pathway

Objective

The long-term clinical practice shows that Zizhu ointment (ZZO) is an empirical formula for the treatment of diabetic ulcers (DUs). In this study, we investigated the underlying mechanism of ZZO in the treatment of DU mice.

Methods

Through streptozotocin induction and high-fat diet, a DU mouse model was established and ZZO was given for treatment. The activation of Notch4 signaling was examined by immunofluorescence staining, RT-PCR, as well as Western blotting. Flow cytometry was performed to detect the counts of F4/80+ cells, M1 and M2 macrophages, as well as the expression of CD11c, CD206, etc. The role of Notch4 in wound healing in diabetic mice was verified by Notch4 inhibitors and agonists.

Results

Accelerated wound healing and decreased expression levels of Notch4 and its target genes and ligands were observed in diabetic mice treated with ZZO. ZZO promoted M2 macrophage polarization, downregulated the expression of proinflammatory factors, and upregulated the levels of anti-inflammatory factors. The same tendency was observed in diabetic mice after treatment with Notch4 inhibitors. Knockout of Notch4 accelerated the wound healing rate as well.

Conclusions

ZZO accelerates wound healing of diabetic mice through inhibiting the activation of Notch4 signaling, promoting M2 macrophage polarization, and alleviating inflammation.

Histatin-1 loaded multifunctional, adhesive and conductive biomolecular hydrogel to treat diabetic wound

Micro-/macroangiopathy, neuropathy and prolonged inflammation are common in diabetic wound, however, traditional wound dressing cannot treat these problems in the same time. Herein, we developed a multifunctional hydrogel with promoted angiogenesis, cell proliferation and anti-inflammation ability to treat diabetic wound. The hydrogel was composed of natural polymers, including gelatin and chitosan, which have excellent biocompatibility. Histatin-1 (His-1) was added into the hydrogel to improve the cell adhesion, proliferation and angiogenesis. Besides, polypyrrole based conductive nanoparticles (G-Ppy) were introduced in the hydrogel to enhance the electrical signal conduction between skin and promote the mechanical strength of the hydrogel. The polypyrrole nanoparticles were growth in the chain of methacryloyl grafted gelatin (Gel-MA), leading to a better biocompatibility and water dispersibility. In vivo wound healing experiment proved that the hydrogel accelerated the wound healing rate, down regulation the expression of pro-inflammation factor TNF-α and upregulation the expression of CD31 and α-SMA, indicating the prospects in the application of diabetic wound healing.

Challenges in Healing Wound: Role of Complementary and Alternative Medicine

Although the word wound sounds like a simple injury to tissue, individual's health status and other inherent factors may make it very complicated. Hence, wound healing has gained major attention in the healthcare. The biology wound healing is precise and highly programmed, through phases of hemostasis, inflammation, proliferation and remodeling. Current options for wound healing which includes, use of anti-microbial agents, healing promoters along with application of herbal and natural products. However, there is no efficient evidence-based therapy available for specific chronic wounds that can result in definitive clinical outcomes. Under co-morbid conditions, chronic would poses numerous challenges. Use of Complementary and Alternative Medicines (CAMs) in health care sector is increasing and its applications in wound management remains like to "separate the diamonds from ore." Attempts have been made to understand the wound at the molecular level, mainly through the analysis of signature genes and the influence of several synthetic and natural molecules on these. We have outlined a review of challenges in chronic wound healing and the role of CAMs in chronic wound management. The main focus is on the applications and limitations of currently available treatment options for a non-healing wound and the best possible alternates to consider. This information generates broader knowledge on challenges in chronic wound healing, which can be further addressed using multidisciplinary approach and combination therapies.

The progress and challenges of circRNA for diabetic foot ulcers: A mini-review

Since the Human Genome Project was successfully completed, humanity has entered a post-genome era, and the second-generation sequencing technology has gradually progressed and become more accurate. Meanwhile, circRNAs plays a crucial role in the regulation of diseases and potential clinical applications has gradually attracted the attention of physicians. However, the mechanisms of circRNAs regulation at the cellular and molecular level of diabetic foot ulcer (DFU) is still not well-understood. With the deepening of research, there have been many recent studies conducted to explore the effect of circRNAs on DFU. In this mini-review, we discuss the potential role of circRNAs as therapeutic targets and diagnostic markers for DFU in order to gain a better understanding of the molecular mechanisms that underlie the development of DFU and to establish a theoretical basis for accurate treatment and effective prevention.

Intracellular Staphylococcus aureus triggers pyroptosis and contributes to inhibition of healing due to Perforin-2 suppression

Impaired wound healing associated with recurrent Staphylococcus aureus infection and unresolved inflammation are hallmarks of non-healing diabetic foot ulcers (DFU). Perforin-2, an innate immunity molecule against intracellular bacteria, limits cutaneous infection and dissemination of S. aureus in mice. Here we report the intracellular accumulation of S. aureus in the epidermis of DFU with no clinical signs of infection due to marked suppression of Perforin-2. S. aureus residing within the epidermis of DFU triggers AIM2-inflammasome activation and pyroptosis. These findings were corroborated in mice lacking Perforin-2. The effects of pyroptosis on DFU clinical outcomes were further elucidated in a 4-week longitudinal clinical study in DFU patients undergoing standard of care. Increased AIM2-inflammasome and ASC-pyroptosome coupled with induction of IL-1β were found in non-healing when compared to healing DFU. Our findings reveal novel mechanism that includes Perforin-2 suppression, intracellular S. aureus accumulation and associated induction of pyroptosis that contribute to healing inhibition and prolonged inflammation in patients with DFU.

Diabetic Wound-Healing Science

Diabetes mellitus is an increasingly prevalent chronic metabolic disease characterized by prolonged hyperglycemia that leads to long-term health consequences. It is estimated that impaired healing of diabetic wounds affects approximately 25% of all patients with diabetes mellitus, often resulting in lower limb amputation, with subsequent high economic and psychosocial costs. The hyperglycemic environment promotes the formation of biofilms and makes diabetic wounds difficult to treat. In this review, we present updates regarding recent advances in our understanding of the pathophysiology of diabetic wounds focusing on impaired angiogenesis, neuropathy, sub-optimal chronic inflammatory response, barrier disruption, and subsequent polymicrobial infection, followed by current and future treatment strategies designed to tackle the various pathologies associated with diabetic wounds. Given the alarming increase in the prevalence of diabetes, and subsequently diabetic wounds, it is imperative that future treatment strategies target multiple causes of impaired healing in diabetic wounds.

Human umbilical cord mesenchymal stem cells in type 2 diabetes mellitus: the emerging therapeutic approach

The umbilical cord has been proved to be an easy-access, reliable, and useful source of mesenchymal stem cells (MSC) for clinical applications due to its primitive, immunomodulatory, non-immunogenic, secretory and paracrine, migratory, proliferative, and multipotent properties. This set of characteristics has recently attracted great research interest in the fields of nanotechnology and regenerative medicine and cellular therapy. Accumulating evidence supports a pronounced therapeutic potential of MSC in many different pathologies, from hematology to immunology, wound-healing, tissue regeneration, and oncology. Diabetes mellitus, branded the epidemic of the century, is considered a chronic metabolic disorder, representing a major burden for health system sustainability and an important public health challenge to modern societies. The available treatments for type 2 diabetes mellitus (T2DM) still rely mainly on combinations of oral antidiabetic agents with lifestyle and nutritional adjustments. Despite the continuous development of novel and better hypoglycemic drugs, their efficacy is limited in the installment and progression of silent T2DM complications. T2DM comorbidities and mortality rates still make it a serious, common, costly, and long-term manageable disease. Recently, experimental models, preclinical observations, and clinical studies have provided some insights and preliminary promising results using umbilical cord MSCs to treat and manage diabetes. This review focuses on the latest research and applications of human-derived umbilical cord MSC in the treatment and management of T2DM, exploring and systematizing the key effects of both umbilical cord MSC and its factor-rich secretome accordingly with the major complications associated to T2DM.

Glycated Hemoglobin (HbA1c) as a Biomarker for Diabetic Foot Peripheral Neuropathy

BACKGROUND

Diabetic peripheral neuropathy (DPN) is known to predict foot ulceration, lower-extremity amputation and mortality. Patients with diabetes mellitus have a predisposition toward developing chronic inflammatory demyelinating polyneuropathy, and this may also facilitate the formation of diabetic foot and cutaneous impairment, which are considered one of the most serious impairments of diabetes mellitus, with a prevalence of 4-10% in this population. Biomarkers research provides opportunities for the early diagnosis of these complications for specific treatments useful to prevent amputation and, therefore, physical inability and mental disturbance. The recent literature has suggested that glycemic levels may be a novel factor in the pathogenesis of diabetic foot complications and is an important mediator of axonal dysfunction. The aim of this systematic literary review is to determine whether hemoglobin A1c (HbA1c) is a positive predictor for diabetic foot peripheral neuropathy and its complications, such as foot cutaneous impairments. There is a lack of consensus regarding the effect of glycemic variability on diabetic foot peripheral neuropathy, unlike other complications such as retinopathy, nephropathy or micro/macrovascular pathology Methods: Relevant articles were searched in the Medline database using PubMed and Scopus and relevant keywords. The primary search terms used were "glycated hemoglobin" OR "HbA1c" AND "diabetic neuropathies" AND "Foot".

RESULTS

A number of articles (336) were initially identified while searching the scientific literature regarding this topic, and 32 articles were selected and included in this review.

CONCLUSIONS

This review highlights the role of HbA1c in diabetic foot peripheral neuropathy. Biomarkers play an important role in the decision-making process, and HbA1c levels are extensively used for diabetic foot clinical outcomes and settings, but biomarker research in diabetic foot peripheral neuropathy is in its infancy and will require careful attention to a number of factors and associations, since the consequences of DPN also include neurological alterations. HbA1c is an accurate and easy-to-administer test and can be an effective biomarker in establishing the diagnosis of diabetes, but future research should focus on standardizing the HbA1c level and selecting which DPN value and its correlated complications, such as foot cutaneous impairments, are the most informative.

[Wound treatment in diabetes patients and diabetic foot ulcers]

Diabetes mellitus (DM) is a paramount and rising medical challenge in both industrial and emerging nations. For Germany, 6.9 million out of 64.9 million insured persons in 2010 were reported to suffer from DM and approximately 5.8 million suffered from type 2 DM. The prevalence of diabetic foot ulcer (DFU) or diabetic foot syndrome (DFS) is 2-10% and the incidence is 2-6%. In addition, patients with DM present associated skin disorders with chronic wound healing, e.g., pyoderma gangrenosum or lecrobiosis lipoidica. Knowledge of the pathogenesis and skills for treatment of chronic wounds in diabetic patients are important for dermatologists. Patients with diabetes and wound healing disorders and accompanied unspecific skin disorders like eczema, cellulitis or contact dermatitis are often primarily or secondarily treated by dermatologists. In this article, practical hints for the treatment of DFS and other chronic wound in patients with DM are presented.

Evaluation of intralesional Candida antigen in diabetic patients with multiple warts

BACKGROUND

Treatment of warts in diabetic patients with ablative modalities poses a significant risk owing to increased possibility of secondary infection, slow healing, and recurrence. Intralesional immunotherapy has gained popularity in the treatment of warts due to its proven efficacy and good tolerability compared with destructive methods.

AIM

To evaluate the intralesional Candida antigen injection for the treatment of multiple warts in diabetic patients.

PATIENTS/METHODS

Fifty diabetic patients with multiple genital/nongenital warts were divided into two groups. The first group (30 patients) received intralesional Candida antigen, and the second group (20 patients) had intralesional saline as control. The treatments were injected into the largest wart every 2 weeks until complete clearance of warts or for a maximum of five sessions.

RESULTS

Complete clearance of warts was observed in 80% of the diabetic patients in the Candida antigen group compared with 15% in the control group (P < .001). Side effects to Candida antigen included pain during injection in all patients, flu-like symptoms, and localized reaction at the injection site in few patients.

CONCLUSION

Intralesional Candida antigen injection can be a promising effective and safe therapeutic option for the treatment of warts in diabetic patients.

A pulsed current electric field alters protein expression creating a wound healing phenotype in human skin cells

Aim: Pulsed current (PC) electric field (EF) devices promote healing in chronic wounds but the underpinning mechanisms are largely unknown. The gap between clinical evidence and mechanistic understanding limits device uptake in clinics. Materials & methods: Migration, proliferation and gene/protein expression profiles were investigated in the presence/absence of PCEF, in skin: keratinocytes (NHK); dermal fibroblasts (HDF); dermal microvascular endothelial cells (HDMEC) and macrophages (THP-1). Results: While PCEF had little effect on migration or proliferation, it significantly altered the expression of 31 genes and the secretion of 7 pro-angiogenic and pro-regenerative growth factors using ELISAs. Conclusion: PCEF significantly altered skin cell genomes/proteomes which provides some evidence of how PCEF devices promote healing of chronic wounds.

Practical context of enzymatic treatment for wound healing: A secreted protease approach (Review)

Skin wounds have been extensively studied as their healing represents a critical step towards achieving homeostasis following a traumatic event. Dependent on the severity of the damage, wounds are categorized as either acute or chronic. To date, chronic wounds have the highest economic impact as long term increases wound care costs. Chronic wounds affect 6.5 million patients in the United States with an annual estimated expense of $25 billion for the health care system. Among wound treatment categories, active wound care represents the fastest-growing category due to its specific actions and lower costs. Within this category, proteases from various sources have been used as successful agents in debridement wound care. The wound healing process is predominantly mediated by matrix metalloproteinases (MMPs) that, when dysregulated, result in defective wound healing. Therapeutic activity has been described for animal secretions including fish epithelial mucus, maggot secretory products and snake venom, which contain secreted proteases (SPs). No further alternatives for use, sources or types of proteases used for wound healing have been found in the literature to date. Through the present review, the context of enzymatic wound care alternatives will be discussed. In addition, substrate homology of SPs and human MMPs will be compared and contrasted. The purpose of these discussions is to identify and propose the stages of wound healing in which SPs may be used as therapeutic agents to improve the wound healing process.

Huangbai Liniment Accelerated Wound Healing by Activating Nrf2 Signaling in Diabetes

As a serious complication of diabetes, nonhealing skin ulcer leads to high mortality and disability in diabetic patients. However, limited therapy is available in managing diabetic wounds. In this study, RNA-seq technology was used to systematically investigate the effect of Huangbai (HB) liniment, a traditional Chinese medicine, on the streptozotocin- (STZ-) induced diabetic wound. HB liniment significantly accelerated the wound closure and enhanced the generation of extracellular matrix in diabetic rats, and oxidative stress was identified to play a vital role in HB-mediated wound healing. Importantly, HB liniment activated nuclear factor erythroid-derived 2-like 2 (Nrf2) and its downstream antioxidant genes (e.g., genes involved in glutathione system, thioredoxin system, and GAPDH generation as well as other antioxidant genes), which inhibited oxidative damage and apoptosis. By associating drug targets of HB liniment with Nrf2 and its downstream genes, 54 components in HB liniment were screened out, and the majority was from Cortex Phellodendri and Forsythia suspensa. Additionally, HB liniment enhanced TGF-β1 and reduced MMP9 level, accelerating wound healing in diabetes. The in vitro experiment showed HB facilitated cell proliferation and inhibited oxidative damage in high glucose-induced HaCaT cells. Our findings provided the experimental evidence for the treatment of diabetic wound with HB, clarified the potential mechanism of HB, and improved our understanding of diabetic wound healing.

Manifestaciones dermatológicas de la diabetes: clasificación y diagnóstico

Se estima que en Colombia hay 2.836.500 adultos con diabetes, una enfermedad con una prevalencia del 8,4 %. La exposición a niveles elevados de glucosa afecta los procesos de proliferación y diferenciación en las células de todos los órganos y tejidos, así mismo en los queratinocitos, fibroblastos y demás células presentes en la piel, alteraciones que ocurren en más de un tercio de los diabéticos y que pueden ser la manifestación inicial de la enfermedad. La frecuencia y presentación de estas dermatosis varía según la población estudiada. La dermopatía diabética, la acantosis nigricans, los fibromas laxos, el prurito y la xerosis son las formas más comunes y se consideran marcadores cutáneos de la diabetes. La presente revisión se enfoca en las manifestaciones dermatológicas específicas y no específicas de la diabetes, así como en las relacionadas con su tratamiento. Estas pueden ser un reflejo del estado metabólico actual o previo del paciente diabético y su oportuna identificación permite orientar el diagnóstico primario, sospechar un estado rediabético u optimizar el tratamiento de la enfermedad en los individuos ya diagnosticados.

Selection of Appropriate Wound Dressing for Various Wounds

There are many factors involved in wound healing, and the healing process is not static. The therapeutic effect of modern wound dressings in the clinical management of wounds is documented. However, there are few reports regarding the reasonable selection of dressings for certain types of wounds in the clinic. In this article, we retrospect the history of wound dressing development and the classification of modern wound dressings. In addition, the pros and cons of mainstream modern wound dressings for the healing of different wounds, such as diabetic foot ulcers, pressure ulcers, burns and scalds, and chronic leg ulcers, as well as the physiological mechanisms involved in wound healing are summarized. This article provides a clinical guideline for selecting suitable wound dressings according to the types of wounds.

Fluorescence Imaging of Mitochondrial Redox State to Assess Diabetic Wounds

Background: Diabetes is known to cause delayed wound healing, and chronic non-healing lower extremity ulcers may end with lower limb amputations and mortalities. Given the increasing prevalence of diabetes mellitus worldwide, it is critical to focus on underlying mechanisms of these debilitating wounds to find novel therapeutic strategies and thereby improve patient outcome. Methods: This study aims to design a label-free optical fluorescence imager that captures metabolic indices (NADH and FAD autofluorescence) and monitors the in vivo wound healing progress noninvasively. Furthermore, 3D optical cryo-imaging of the mitochondrial redox state was utilized to assess the volumetric redox state of the wound tissue. Results: The results from our in vivo fluorescence imager and the 3D cryo-imager quantify the differences between the redox state of wounds on diabetic mice in comparison with the control mice. These metabolic changes are associated with mitochondrial dysfunction and higher oxidative stress in diabetic wounds. A significant correlation was observed between the redox state and the area of the wounds. Conclusion: The results suggest that our developed novel optical imaging system can successfully be used as an optical indicator of the complex wound healing process noninvasively.

Comparing skin characteristics and molecular markers of xerotic foot skin between diabetic and non-diabetic subjects: An exploratory study

BACKGROUND

Xerosis cutis of the feet is one of the most common skin conditions among type 2 diabetics. Whether skin dryness among diabetic patients is different from 'general' skin dryness is unclear. The overall aim was to compare the structure, function and molecular markers of dry and cracked foot skin between diabetics and non-diabetics.

METHODS

The foot skin of 40 diabetics and 20 non-diabetics was evaluated. A clinical assessment of skin dryness was performed and transepidermal water loss, stratum corneum hydration, skin surface pH, epidermal thickness, skin roughness, elasticity and structural stiffness were measured. Ceramides, natural moisturizing factors, histamines, proteins and molecular markers of oxidative stress were analyzed based on a non-invasive sampling method for collection of surface biomarkers.

RESULTS

The mean number of superficial fissures in the diabetic group was nearly three times higher than in the non-diabetic group (11.0 (SD 6.2) vs. 3.9 (SD 4.2)). The skin stiffness was higher in the diabetic group and the values of almost all molecular markers showed considerably higher values compared to non-diabetics. Malondialdehyde and glutathione were lower in the diabetic sample.

CONCLUSIONS

The high number of superficial fissures may be based on an increased stiffness of dry diabetic foot skin combined with different concentrations of molecular markers in the stratum corneum compared to dry foot skin of non-diabetics.

Skin Acute Wound Healing: A Comprehensive Review

Experimental work of the last two decades has revealed the general steps of the wound healing process. This complex network has been organized in three sequential and overlapping steps. The first step of the inflammatory phase is an immediate response to injury; primary sensory neurons sense injury and send danger signals to the brain, to stop bleeding and start inflammation. The following target of the inflammatory phase, led by the peripheral blood mononuclear cells, is to eliminate the pathogens and clean the wound. Once this is completed, the inflammatory phase is resolved and homeostasis is restored. The aim of the proliferative phase, the second phase, is to repair wound damage and begin tissue remodeling. Fibroplasia, reepithelialization, angiogenesis, and peripheral nerve repair are the central actions of this phase. Lastly, the objective of the final phase is to complete tissue remodeling and restore skin integrity. This review provides present day information regarding the status of the participant cells, extracellular matrix, cytokines, chemokines, and growth factors, as well as their interactions with the microenvironment during the wound healing process.

The Dynamics of the Skin's Immune System

The skin is a complex organ that has devised numerous strategies, such as physical, chemical, and microbiological barriers, to protect the host from external insults. In addition, the skin contains an intricate network of immune cells resident to the tissue, crucial for host defense as well as tissue homeostasis. In the event of an insult, the skin-resident immune cells are crucial not only for prevention of infection but also for tissue reconstruction. Deregulation of immune responses often leads to impaired healing and poor tissue restoration and function. In this review, we will discuss the defensive components of the skin and focus on the function of skin-resident immune cells in homeostasis and their role in wound healing.

Negative pressure wound therapy promoted wound healing by suppressing inflammation via down-regulating MAPK-JNK signaling pathway in diabetic foot patients

AIMS

Negative pressure wound therapy displayed significant clinical benefits in the healing of diabetic foot wounds. In the present study, we investigated the mechanism of regulation of MAPK-JNK (Mitogen-activated protein kinase- c-Jun N-terminal kinase) signaling pathway by negative pressure wound therapy on these wounds.

METHODS

Twenty-six type 2 diabetes patients with foot ulceration were randomly assigned to the two groups, thirteen treated with negative pressure wound therapy and the others treated with traditional debridement therapy. Skin samples were harvested and histologically and immunohistochemical analyzed in both groups. Immunofluorescence stain, Enzyme-linked immunosorbent assay and Western blotting were performed for inducible nitric oxide synthase, inter leukin-6, tumor necrosis factor-α, P-c-Jun N-terminal kinase and c-Jun N-terminal kinase. Real time-polymerase chain reaction was performed to evaluate expression of c-Jun N-terminal kinase, extracellular signal regulated kinase1/2 and p38.

RESULTS

Negative pressure wound therapy could effectively alleviate inflammatory reaction and reduce inter leukin-6 and inducible nitric oxide synthase production after 7 days treatment. The level of tumor necrosis factor-α, inter leukin-6 and P-c-Jun N-terminal kinase were significantly decreased. However, there was no statistical difference in messenger ribonucleic acid expression of p38, extracellular signal regulated kinase1 and 2.

CONCLUSIONS

Negative pressure wound therapy possibly suppress the wound inflammation by inhibiting inter leukin-6, tumor necrosis factor-α and inducible nitric oxide synthase in diabetic foot patients. This effect is maybe mediated at least in part by suppression of Mitogen-activated protein kinase- c-Jun N-terminal kinase signaling pathway.

Immune aging in diabetes and its implications in wound healing

Immune systems have evolved to recognize and eliminate pathogens and damaged cells. In humans, it is estimated to recognize 109 epitopes and natural selection ensures that clonally expanded cells replace unstimulated cells and overall immune cell numbers remain stationary. But, with age, it faces continuous repertoire restriction and concomitant accumulation of primed cells. Changes shaping the aging immune system have bitter consequences because, as inflammatory responses gain intensity and duration, tissue-damaging immunity and inflammatory disease arise. During inflammation, the glycolytic flux cannot cope with increasing ATP demands, limiting the immune response's extent. In diabetes, higher glucose availability stretches the glycolytic limit, dysregulating proteostasis and increasing T-cell expansion. Long-term hyperglycemia exerts an accumulating effect, leading to higher inflammatory cytokine levels and increased cytotoxic mediator secretion upon infection, a phenomenon known as diabetic chronic inflammation. Here we review the etiology of diabetic chronic inflammation and its consequences on wound healing.

Platelet-rich plasma for the treatment of diabetic foot ulcers: A meta-analysis

Foot ulcer is a major complication of diabetes mellitus and often precedes leg amputation. Among the different methods to achieve ulcer healing, the use of platelet-rich plasma, which is rich in multiple growth factors and cytokines and may have similarities to the natural wound healing process, is gaining in popularity. A systematic review with meta-analyses was performed to evaluate the safety and clinical effectiveness of platelet-rich plasma for the treatment of diabetic foot ulcers compared to standard treatment or any other alternative therapy. The electronic databases Medline, EMBASE, CINAHL, and Cochrane Central Register of Controlled Trials were consulted in March 2017 with no restrictions placed on the publication date. Predefined criteria were used to determine inclusion of studies and to assess their methodologic quality. Eight randomized clinical trials and two prospective longitudinal-observational studies with control group were included. Platelet-rich plasma treatment increased the likelihood of chronic wound healing (RR = 1.32; 95% CI: 1.11, 1.57, I² = 15%) while the volume of the ulcer (MD = 0.12 cm² ; 95% CI: 0.08, 0.16; p < 0.01; I² = 0%) and time to complete wound healing (MD = -11.18 days; 95% CI: -20.69, -1.68; I² = 53%) decreased. Regarding safety profile, platelet-rich plasma did not differ from standard treatment in terms of probability of occurrence of wound complications (RR = 0.57; 95% CI: 0.25, 1.28; I² = 0%) or recurrences (RR = 2.76; 95% CI: 0.23, 33.36; p = 0.43; I² = 82%) but it decreased the rate of adverse events (RR = 0.80; 95% CI: 0.66, 0.96; p = 0.02; I² = 0%). Cumulative meta-analysis revealed that there is enough evidence to demonstrate a statistically significant benefit. However, studies included presented serious methodologic flaws. According to the results, platelet-rich plasma could be considered a candidate treatment for nonhealing of diabetic foot ulcers.

Relation between cutaneous and extracutaneous complications in pediatric patients with type 1 diabetes

Background: The relationship between cutaneous and extracutaneous complications in pediatric patients with type 1 diabetes is unclear. Objective: The objective of the current study is to investigate the relationship between skin disorders and diabetic microangiopathic changes in pediatric and adolescent patients with type 1 diabetes. Patients and methods: Eighty patients with type 1 diabetes and 50 healthy controls were enrolled in the study. All recruited patients were followed up monthly for a total period of 12 month. Monthly visit included thorough clinical examination with system review, as well as whole-body cutaneous examination. HbA1c was assessed every 3 month. Twenty-four hours urine was collected for measurement of urinary albumin. Results: Fifty percent of the screened diabetic cohort had diabetic nephropathy (DN). The overall prevalence of cutaneous lesion among the studied diabetic cohort was high (72.5%), with cutaneous infections (40%) and xerosis (30%) being the most prevalent. The frequency of cutaneous infections, xerosis and rubeosis faciei was higher in patients with nephropathy than in those without nephropathy. Conclusion: cutaneous affection in patients with diabetes may be a clue to the presence of associated microangioapthic complications. The significant association between diabetic nephropathy and cutaneous lesions support the concept that cutaneous lesion in diabetes is a reflection of diabetic angiopathy, highlighting the importance of identifying patients at risk of other microvascular complications.

Potentiation effect on accelerating diabetic wound healing using 2-N,6-O-sulfated chitosan-doped PLGA scaffold

Accelerating the wound healing of diabetes-impaired cutaneous tissue is still a challenge due to the aberrant cellular behavior, poor angiogenesis, and pathological micro-environment. Activation with growth factors and modulation of the redox micro-environment of the diabetic wound are considered to be effective strategies. Herein, we have described a highly sulfated heparin-like polysaccharide 2-N, 6-O-sulfated chitosan (26SCS)-doped poly(lactic-co-glycolic acid) scaffold (S-PLGA), which can achieve controlled and sustained release of heparin-binding epidermal growth factor (HB-EGF) owing to its affinity for heparin-binding growth factors. Interestingly, the antioxidant effect of 26SCS was confirmed and it was shown to have a strong scavenging activity towards superoxide radicals, a moderate scavenging activity towards hydroxyl radicals and a lower scavenging activity towards hydrogen peroxide. It also exhibited stronger protective effects in a human keratinocyte cell line (Ha-cat) against H₂O₂-induced oxidative damage. The Ha-cat cells cultured in the presence of the S-PLGA scaffold were significantly protected against oxidative stress during proliferation. In a full thickness excisional wound model of a diabetic rat, the wound treated with the HB-EGF-loaded S-PLGA scaffold was basically healed after 28 days. Conversely, the wounds in the other diabetic groups were not closed. The migration effect of the keratinocytes was enhanced by the 26SCS-induced sustainable release of HB-EGF and the scavenging of ROS which led to rapid re-epithelialization. Furthermore, histopathological evaluation demonstrated the positive effects on wound contraction, epithelial regeneration, and collagen deposition when treated with the HB-EGF loaded S-PLGA scaffold. These findings highlight that 26SCS may serve as a promising coagent for both controlled release of growth factors and alleviation of excessive ROS production, thus leading to increased regeneration of the diabetic wounds.

Hesperidin enhances angiogenesis via modulating expression of growth and inflammatory factor in diabetic foot ulcer in rats

One of the most devastating consequences of diabetes mellitus is a chronic condition, diabetic foot ulcer. Numerous investigations are being targeted to explore newer compounds for treatment of diabetic foot ulcer wounds in diabetic patients. Hesperidin (HSP), an isoflavone glycoside has been established to exhibit antidiabetic and antioxidant potential. In the current investigation, diabetes was induced in rats by administration by streptozotocin (STZ) intraperitoneally (50 mg/kg). Wound-healing capacity was estimated in hind paw of rats by artificially initiating wound injury on the paw dorsal surface. The injured animals were administered with incremental doses of HSP suspension orally (10, 20, 40, 60, and 80 mg/kg) and insulin subcutaneously (10 IU/kg). Parameters such as wound area were estimated every 2 days, and at the end of 20 days of study, biochemical estimations in serum and histopathological observations of the wound were made. HSP (60 and 80 mg/kg) revealed statistically significant ( P < 0.05) improvement in wound dimension, glucose and insulin concentration, and glycated hemoglobin (HbA1C). Administration of HSP indicated significant ( P < 0.05) modulation of mRNA associated with expression of vascular endothelial growth factor (VEGF), whereas the levels of tumor necrosis factor (TNF)-α and interleukin (IL)-6 levels were lowered compared to the control group of animals. Real-time quantitative polymerase chain reaction (RT-qPCR) indicated expression of vascular endothelial growth factor receptors 1 and 2 (VEGFR1 and VEGFR2) compared to glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Histological observations indicated higher expression of VEGF in the groups receiving HSP, indicative of angiogenesis stimulation in the diabetic wound. The results advocate angiogenesis activity of HSP was enhanced owing to reduction in hyperglycemia and oxidative stress–induced damage, reduced expression of inflammatory mediators, and enhanced expression of growth-related factors, thereby promoting healing of diabetic foot ulcer.