Improvement of diabetic wound healing by topical application of Vicenin-2 hydrocolloid film on Sprague Dawley rats

Phytoconstituents as modulators of NF-κB signalling: Investigating therapeutic potential for diabetic wound healing

The NF-κB pathway plays a pivotal role in impeding the diabetic wound healing process, contributing to prolonged inflammation, diminished angiogenesis, and reduced proliferation. In contrast to modern synthetic therapies, naturally occurring phytoconstituents are well-studied inhibitors of the NF-κB pathway that are now attracting increased attention in the context of diabetic wound healing because of lower toxicity, better safety and efficacy, and cost-effectiveness. This study explores recent research on phytoconstituent-based therapies and delve into their action mechanisms targeting the NF-κB pathway and potential for assisting effective healing of diabetic wounds. For this purpose, we have carried out surveys of recent literature and analyzed studies from prominent databases such as Science Direct, Scopus, PubMed, Google Scholar, EMBASE, and Web of Science. The classification of phytoconstituents into various categorie such as: alkaloids, triterpenoids, phenolics, polyphenols, flavonoids, monoterpene glycosides, naphthoquinones and tocopherols. Noteworthy phytoconstituents, including Neferine, Plumbagin, Boswellic acid, Genistein, Luteolin, Kirenol, Rutin, Vicenin-2, Gamma-tocopherol, Icariin, Resveratrol, Mangiferin, Betulinic acid, Berberine, Syringic acid, Gallocatechin, Curcumin, Loureirin-A, Loureirin-B, Lupeol, Paeoniflorin, and Puerarin emerge from these studies as promising agents for diabetic wound healing through the inhibition of the NF-κB pathway. Extensive research on various phytoconstituents has revealed how they modulate signalling pathways, including NF-κB, studies that demonstrate the potential for development of therapeutic phytoconstituents to assist healing of chronic diabetic wounds.

Translational Challenges in Drug Therapy and Delivery Systems for Treating Chronic Lower Extremity Wounds

Despite several promising preclinical studies performed over the past two decades, there remains a paucity of market-approved drugs to treat chronic lower extremity wounds in humans. This translational gap challenges our understanding of human chronic lower extremity wounds and the design of wound treatments. Current targeted drug treatments and delivery systems for lower extremity wounds rely heavily on preclinical animal models meant to mimic human chronic wounds. However, there are several key differences between animal preclinical wound models and the human chronic wound microenvironment, which can impact the design of targeted drug treatments and delivery systems. To explore these differences, this review delves into recent new drug technologies and delivery systems designed to address the chronic wound microenvironment. It also highlights preclinical models used to test drug treatments specific for the wound microenvironments of lower extremity diabetic, venous, ischemic, and burn wounds. We further discuss key differences between preclinical wound models and human chronic wounds that may impact successful translational drug treatment design.

Hydrogel dressings for diabetic foot ulcer: A systematic review and meta-analysis

AIM

To investigate the differences in utility between conventional dressings and hydrogel dressings for the treatment of diabetic foot ulcer (DFU).

METHODS

The PubMed, Embase, Cochrane Library, CNKI, VIP and Wanfang databases were systematically searched up to 21 January 2023. Fixed/random-effect models were used to calculate the odds ratios (ORs) and mean differences (MDs) with 95% confidence intervals (CIs) for the effect size analysis, with heterogeneity determined by I2 statistics. Subgroup analyses of different classes of hydrogel were also conducted.

RESULTS

A total of 15 randomized controlled trials with 872 patients were eligible for the present analysis. Compared with conventional dressings, hydrogel dressings significantly improved the healing rate (OR 4.09, 95% CI 2.83 to 5.91), shortened the healing time (MD -11.38, 95% CI -13.11 to -9.66), enhanced granulation formation (MD -3.60, 95% CI -4.21 to -3.00) and epithelial formation (MD -2.82, 95% CI -3.19 to -2.46), and reduced the incidence of bacterial infection (OR 0.10, 95% CI 0.05 to 0.18).

CONCLUSION

The meta-analysis showed that hydrogel dressings are more effective in treating DFU compared with conventional dressings.

Lycopene potentiates wound healing in streptozotocin-induced diabetic rats

Background

Diabetes is a growing metabolic disease that is characterized by high blood sugar levels with life-threatening results. Diabetic wounds are a major problem because they do not resolve in few days. Major problems affecting wound healing are infection, age, stress, etc. at the wound site, and other associated disease conditions. Lycopene is a red pigment obtained from various fruits such as tomatoes, watermelon, and guava. It is a powerful antioxidant that scavenges reactive oxygen species and potential as nutraceuticals. It has reported antidiabetic, antioxidant, anti-obesity, anti-inflammatory, antihyperglycemic, and antiaging activities based on the literature.

Objective

The objective of the current study is to find the wound-healing potential of lycopene emulgel (LE) and report the properties of the compound.

Methods

Wound healing activity was assessed in Streptozotocin induced diabetic rats and control rats. Streptozotocin injection (55 mg/kg) was used to induce marked hyperglycaemia, compared with controls. The formulation was applied topically and was evaluated for efficacy.

Results

Treatment of rats with lycopene emulgel (LE) topical application exhibited a significant reduction of wound closure of 95.3 and 88.9% and epithelisation within 21 days.

Conclusion

The formulation was found to be novel, safe, and effective in the functional recovery of wounds.

Exploring polysaccharide-based bio-adhesive topical film as a potential platform for wound dressing application: A review

Wound dressings act as a physical barrier between the wound site and the external environment, preventing additional harm; choosing suitable wound dressings is essential for the healing process. Polysaccharide biopolymers have demonstrated encouraging findings and therapeutic prospects in recent decades about wound therapy. Additionally, polysaccharides have bioactive qualities like anti-inflammatory, antibacterial, and antioxidant capabilities that can help the process of healing. Due to their excellent tissue adhesion, swelling, water absorption, bactericidal, and immune-regulating properties, polysaccharide-based bio-adhesive films have recently been investigated as intriguing alternatives in wound management. These films also mimic the structure of the skin and stimulate the regeneration of the skin. This review presented several design standards and functions of suitable bio-adhesive films for the healing of wounds. Additionally, the most recent developments in the use of bio-adhesive films as wound dressings based on polysaccharides, including hyaluronic acid, chondroitin sulfate, dextran, alginate, chitosan, cellulose, konjac glucomannan, gellan gum, xanthan gum, pectin, guar gum, heparin, arabinogalactans, carrageen, and tragacanth gum, are thoroughly discussed. Lastly, to create a road map for the function of polysaccharide-based bio-adhesive films in advanced wound care, their clinical performances and future challenges in making bio-adhesive films by three-dimensional bioprinting are summarized.

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

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

Targeting Signalling Pathways in Chronic Wound Healing

Chronic wounds fail to achieve complete closure and are an economic burden to healthcare systems due to the limited treatment options and constant medical attention. Chronic wounds are characterised by dysregulated signalling pathways. Research has focused on naturally derived compounds, stem-cell-based therapy, small molecule drugs, oligonucleotide delivery nanoparticles, exosomes and peptide-based platforms. The phosphoinositide-3-kinase (PI3K)/protein kinase B (AKT), Wingless-related integration (Wnt)/β-catenin, transforming growth factor-β (TGF-β), nuclear factor erythroid 2-related factor 2 (Nrf2), Notch and hypoxia-inducible factor 1 (HIF-1) signalling pathways have critical roles in wound healing by modulating the inflammatory, proliferative and remodelling phases. Moreover, several regulators of the signalling pathways were demonstrated to be potential treatment targets. In this review, the current research on targeting signalling pathways under chronic wound conditions will be discussed together with implications for future studies.

Natural Polymeric Hydrogels Encapsulating Small Molecules for Diabetic Wound Healing

Diabetes is a condition correlated with a high number of diagnosed chronic wounds as a result of a complex pathophysiological mechanism. Diabetic chronic wounds are characterized by disorganized and longer stages, compared to normal wound healing. Natural polymer hydrogels can act as good wound dressings due to their versatile physicochemical properties, represented mainly by high water content and good biocompatibility. Natural bioactive hydrogels are polymers loaded with bioactive compounds providing antibacterial and antioxidant properties, modulation of inflammation and adherence to wounded tissue, compared to traditional dressings, which enables promising future applications for diabetic wound healing. Natural bioactive compounds, such as polyphenols, polysaccharides and proteins have great advantages in promoting chronic wound healing in diabetes due to their antioxidant, anti-inflammatory, antimicrobial, anti-allergic and wound healing properties. The present paper aims to review the wound healing mechanisms underlining the main issues of chronic wounds and those specifically occurring in diabetes. Also, the review highlights the recent state of the art related to the effect of hydrogels enriched with natural bioactive compounds developed as biocompatible functional materials for improving diabetic-related chronic wound healing and providing novel therapeutic strategies that could prevent limb amputation and increase the quality of life in diabetic patients.

Bioinspired 3D-printed scaffold embedding DDAB-nano ZnO/nanofibrous microspheres for regenerative diabetic wound healing

There is a constant demand for novel materials/biomedical devices to accelerate the healing of hard-to-heal wounds. Herein, an innovative 3D-printed bioinspired construct was developed as an antibacterial/regenerative scaffold for diabetic wound healing. Hyaluronic/chitosan (HA/CS) ink was used to fabricate a bilayer scaffold comprising a dense plain hydrogel layer topping an antibacterial/regenerative nanofibrous layer obtained by incorporating the hydrogel with polylactic acid nanofibrous microspheres (MS). These were embedded with nano ZnO (ZNP) or didecyldimethylammonium bromide (DDAB)-treated ZNP (D-ZNP) to generate the antibacterial/healing nano/micro hybrid biomaterials, Z-MS@scaffold and DZ-MS@scaffold. Plain and composite scaffolds incorporating blank MS (blank MS@scaffold) or MS-free ZNP@scaffold and D-ZNP@scaffold were used for comparison. 3D printed bilayer constructs with customizable porosity were obtained as verified by SEM. The DZ-MS@scaffold exhibited the largest total pore area as well as the highest water-uptake capacity andin vitroantibacterial activity. Treatment ofStaphylococcus aureus-infected full thickness diabetic wounds in rats indicated superiority of DZ-MS@scaffold as evidenced by multiple assessments. The scaffold afforded 95% wound-closure, infection suppression, effective regulation of healing-associated biomarkers as well as regeneration of skin structure in 14 d. On the other hand, healing of non-diabetic acute wounds was effectively accelerated by the simpler less porous Z-MS@scaffold. Information is provided for the first-time on the 3D printing of nanofibrous scaffolds using non-electrospun injectable bioactive nano/micro particulate constructs, an innovative ZNP-functionalized 3D-printed formulation and the distinct bioactivity of D-ZNP as a powerful antibacterial/wound healing promotor. In addition, findings underscored the crucial role of nanofibrous-MS carrier in enhancing the physicochemical, antibacterial, and wound regenerative properties of DDAB-nano ZnO. In conclusion, innovative 3D-printed DZ-MS@scaffold merging the MS-boosted multiple functionalities of ZNP and DDAB, the structural characteristics of nanofibrous MS in addition to those of the 3D-printed bilayer scaffold, provide a versatile bioactive material platform for diabetic wound healing and other biomedical applications.

Wound healing potential of Acacia catechu in streptozotocin-induced diabetic mice using in vivo and in silico approach

Background and aim

Acacia catechu Wild. (Fabaceae) barks are traditionally used in the treatment of diabetes and wounds. Therefore, the objective of the present study was to evaluate the wound healing potential of the alcoholic extract of A. catechu (EAC) in streptozotocin-induced diabetic mice.

Experimental procedures

EAC was first subjected to phytochemical estimations and standardization using (-) epicatechin as marker with the help of HPLC. Diabetes was induced in mice using streptozotocin and the wound healing potential of EAC was evaluated using excision and incision wound models on topical and oral treatment. Various biochemical parameters, in vivo antioxidants, cytokine profiling, VEGF, and histopathological examination were also performed. Further, molecular docking studies were performed using ligand (-) epicatechin on human inducible nitric oxide synthase.

Results and conclusion

Phytochemically, EAC showed the presence of tannins, flavonoids, phenolic compounds, and saponins, while the content of (-) epicatechin was reported to be 7.81% w/w. The maximum healing of wounds (91.84 ± 1.10%) was observed in mice treated with a combination of both topical (10% gel) and oral (extract at 200 mg/kg) followed by topically and orally treated groups respectively after 14 days of treatment. These groups also showed significant restoration of altered biochemical parameters, antioxidant enzymes and cytokines. The molecular docking studies confirmed the role of (-) epicatechin in stabilizing the human inducible nitric oxide synthase with inhibitor showing binding energy of -8.31 kcal/mol. The present study confirmed the role of (-) epicatechin as a major marker in diabetic wound healing potential of A. catechu.

The Garlic Tree of Borneo, Scorodocarpus borneensis (Baill.) Becc. (Olacaceae): Potential Utilization in Pharmaceutical, Nutraceutical, and Functional Cosmetic Industries

Scorodocarpus borneensis (Baill.) Becc. is attracting increased attention as a potential commercial medicinal plant product in Southeast Asia. This review summarizes the current knowledge on the taxonomy, habitat, distribution, medicinal uses, natural products, pharmacology, toxicology, and potential utilization of S. borneesis in the pharmaceutical/nutraceutical/functional cosmetic industries. All data in this review were compiled from Google Scholar, PubMed, Science Direct, Web of Science, ChemSpider, PubChem, and a library search from 1866 to 2022. A total of 33 natural products have been identified, of which 11 were organosulfur compounds. The main organosulfur compound in the seeds is bis-(methylthiomethyl)disulfide, which inhibited the growth of a broad spectrum of bacteria and fungi, T-lymphoblastic leukemia cells, as well as platelet aggregation. Organic extracts evoked anti-microbial, cytotoxic, anti-free radical, and termiticidal effects. S. borneensis and its natural products have important and potentially patentable pharmacological properties. In particular, the seeds have the potential to be used as a source of food preservatives, antiseptics, or termiticides. However, there is a need to establish acute and chronic toxicity, to examine in vivo pharmacological effects and to perform clinical studies.

Mechanisms of action underlying the effect of Tongsaimai on wound healing based on experimental and network pharmacology

ETHNOPHARMACOLOGICAL RELEVANCE

Tongsaimai (TSM) is a traditional Chinese medicine that has several therapeutic qualities, including anti-inflammatory, anti-oxidative, and anti-vasculitis effects. However, its impacts and underlying mechanisms on wound healing remain unclear.

AIM OF THE STUDY

The aim of our study was to evaluate TSM for its pro-healing effect and the relevant mechanisms using both experimental validation and network pharmacology analysis.

MATERIALS AND METHODS

The components of TSM were detected by high-performance liquid chromatography combined with diode array detector (HPLC-DAD). Skin wounds with a diameter of 4 mm were created on the backs of mice, after which, topical treatments of 2.5-10% TSM were applied onto the lesions once daily for either 2 or 7 days. Then, the wound tissues were collected to determine the impacts of TSM on collagen deposition, epithelial cell proliferation, oxidative stress, inflammation, and angiogenesis. Moreover, the effects of TSM (0.5-2 mg/mL) on the cell viability of HUVECs and HaCaT cells were evaluated.

RESULTS

A total of 11 components in TSM were identified by HPLC-DAD. TSM was found to enhance the rate of wound contraction and increase epithelial thickness and collagen deposition during the healing process. In addition, TSM increased SOD activity and downregulated MDA and IL-1β levels in the wound tissues. Immunofluorescence analysis further indicated an increased expression of Ki67, CD31, and VEGF in wound tissues following TSM administration. Results of the network pharmacology analysis revealed that multiple pathways including VEGF, PI3K/Akt, and MAPK pathways were involved in the pharmacological actions of TSM on wound healing. Accordantly, in vitro experiments revealed that TSM promoted the proliferation of HUVECs and HaCaT cells while activating the PI3K/Akt pathway.

CONCLUSIONS

Our results suggest that TSM may serve as a therapeutic medication to improve wound healing by employing multiple regulatory mechanisms that affect proliferation, angiogenesis, collagen deposition, oxidative stress, and inflammation.

Development of Biocellulose Sheet Incorporating Aloe vera Gel Extract for Diabetic Wound Healing

In this study, a biocellulose (BC) sheet containing Aloe vera gel extract (AE) was developed for application in healing chronic wounds, such as diabetic wounds. The BC sheet was produced by Acetobacter xylinum and then lyophilized to obtain dried sheets. A. vera gel was extracted by precipitation in 35% ammonium sulfate, lyophilized, dried, and incorporated into the BC sheet. The protein content of the AE was 12.32 ± 3.4% w/w, with a molecular weight of ∼20 kDa. The release of TNF-α from lipopolysaccharide-induced RAW264.7 cells was reduced by treatment with AE in a dose-dependent manner. The physicochemical and biological properties of the developed sheet were investigated. Morphological examination of the BC/AE sheet using scanning electron microscopy revealed the 3D construction of nanofibrils, which showed high porosity. The BC/AE sheet exhibited water absorption at 74%, and the release of proteins in the AE reached 97.23% at 4 h. The BC sheet incorporated with proteins in the AE at 283.78 ± 7.7 μg/cm² can promote the wound healing in streptozotocin-induced diabetic rats. The recovering skin in diabetic wounds treated with the BC/AE sheet exhibited a normal cell arrangement without fibrosis, as revealed by histological staining. The research findings indicate that the BC/AE sheet has potential for applications in wound dressings.

Advanced polymer hydrogels that promote diabetic ulcer healing: mechanisms, classifications, and medical applications

Diabetic ulcers (DUs) are one of the most serious complications of diabetes mellitus. The application of a functional dressing is a crucial step in DU treatment and is associated with the patient's recovery and prognosis. However, traditional dressings with a simple structure and a single function cannot meet clinical requirements. Therefore, researchers have turned their attention to advanced polymer dressings and hydrogels to solve the therapeutic bottleneck of DU treatment. Hydrogels are a class of gels with a three-dimensional network structure that have good moisturizing properties and permeability and promote autolytic debridement and material exchange. Moreover, hydrogels mimic the natural environment of the extracellular matrix, providing suitable surroundings for cell proliferation. Thus, hydrogels with different mechanical strengths and biological properties have been extensively explored as DU dressing platforms. In this review, we define different types of hydrogels and elaborate the mechanisms by which they repair DUs. Moreover, we summarize the pathological process of DUs and review various additives used for their treatment. Finally, we examine the limitations and obstacles that exist in the development of the clinically relevant applications of these appealing technologies. This review defines different types of hydrogels and carefully elaborate the mechanisms by which they repair diabetic ulcers (DUs), summarizes the pathological process of DUs, and reviews various bioactivators used for their treatment.

Preclinical animal study of electrospun poly (l-lactide-co-caprolactone) and formulated porcine fibrinogen for full-thickness diabetic wound regeneration

Diabetic foot ulcer is one of the most serious chronic complications of diabetes mellitus. It may lead to amputation of the lower extremities for diabetics. Our study was to evaluate the effect of electrospun poly (L-lactide-co-caprolactone) and formulated porcine fibrinogen (PLCL/Fg) wound dressing on animal wound model. A blend ratio of PLCL/Fg scaffold was 4 (PLCL):1 (Fg). The scanning electron microscopy findings showed that the fibers' diameter was 122.5 ± 80.3 nm, and the tensile strength was 9.2 ± 0.2 MPa. In-vivo study of the hog normal model demonstrated that PLCL/Fg dressing had better biocompatibility, degradability, and ability to restore the skin's normal structure. We evaluated the wound healing processes in the rat diabetic model by macroscopic observation and histological observation at 1, 2, and 3 post-operation weeks. In our study, the PLCL/Fg group performed better 3 weeks after surgery, in terms of macroscopic healing and scarring. After surgery, the PLCL/Fg group showed better fibroblast accumulation, tissue granulation, and collagen expression than the control group. Topical treatment with PLCL/Fg dressing effectively enhanced wound healing in both normal and hyperglycemic conditions, suggesting that it may possess wound-healing potential.

Why traditional herbal medicine promotes wound healing: Research from immune response, wound microbiome to controlled delivery

Impaired wound healing in chronic wounds has been a significant challenge for clinicians and researchers for decades. Traditional herbal medicine (THM) has a long history of promoting wound healing, making them culturally accepted and trusted by a great number of people in the world. However, for a long time, the understanding of herbal medicine has been limited and incomplete, particularly in the allopathic medicine-dominated research system. The therapeutic effects of individual components isolated from THM are found less pronounced compared to synthetic chemical medicine, and the clinical efficacy is always inferior to herbs. In the present article, we review and discuss underlying mechanisms of the skin microbiome involved in the wound healing process; THM in regulating immune responses and commensal microbiome. We additionally propose few pioneer ideas and studies in the development of therapeutic strategies for controlled delivery of herbal medicine. This review aims to promote wound care with a focus on wound microbiome, immune response, and topical drug delivery systems. Finally, future development trends, challenges, and research directions are discussed.

Phytotherapy in Diabetic Foot Ulcers: A Promising Strategy for Effective Wound Healing

Despite the advancement in wound care, the effective therapy of chronic diabetic ulcers continues to be a challenge. Wound healing is a highly controlled process, which involves a sequence of complex overlapping steps. This healing pathway comprises of hemostasis, inflammation, proliferative, and remodeling phases. Recent evidence suggests that phytomedicines can prevent or repair different kinds of destructive cellular damage, including chronic wounds. Several phytochemicals such as polyphenols, alkaloids, flavonoids, terpenoids, and glycosides have pleiotropic effects, including stimulation of fibroblast proliferation, the main step in wound healing. Besides, the mechanism involves induction of collagen synthesis, migration, and reepithelization and their antimicrobial, antioxidant, anti-inflammatory, and immunomodulatory actions. Similarly, the use of phytochemicals alone or as an adjuvant with standard therapy has demonstrated promising results in managing complications in the diabetic foot. For instance, the extract of Carica papaya has been shown antioxidant, antimicrobial, and anti-inflammatory, and immunomodulatory effects, which, together with proteolytic enzymatic activity, contributes to its wound healing property. It is generally believed that phytotherapy has no or minimal toxicity than synthetic therapeutic agents, favoring its use in diabetic foot ulcer management. The current review highlights the selected phytochemicals and their sources; and potential application in diabetic foot ulcer management.Key teaching points and nutritional relevanceCurrently, phytochemicals have been shown wide potential in disease. management including alleviating clinical manifestations, preventing degenerative disease, and curing illness.Increased evidence of phytochemical as anti-infective and anti-inflammatory suggests its role in the management of diabetic foot ulcer(DFU).Potential benefit along with minimal adverse effect favors its application as adjuvant therapy.Further research is needed to standardize its dose and formulation to enhance its clinical application in DFU management.

Therapeutic Efficacy of Polymeric Biomaterials in Treating Diabetic Wounds-An Upcoming Wound Healing Technology

Diabetic wounds are one of the serious, non-healing, chronic health issues faced by individuals suffering from diabetic mellitus. The distinct phases of wound healing are either prolonged or obstructed, resulting in the improper healing of diabetic wounds. These injuries require persistent wound care and appropriate treatment to prevent deleterious effects such as lower limb amputation. Although there are several treatment strategies, diabetic wounds continue to be a major threat for healthcare professionals and patients. The different types of diabetic wound dressings that are currently used differ in their properties of absorbing wound exudates and may also cause maceration to surrounding tissues. Current research is focused on developing novel wound dressings incorporated with biological agents that aid in a faster rate of wound closure. An ideal wound dressing material must absorb wound exudates, aid in the appropriate exchange of gas, and protect from microbial infections. It must support the synthesis of biochemical mediators such as cytokines, and growth factors that are crucial for faster healing of wounds. This review highlights the recent advances in polymeric biomaterial-based wound dressings, novel therapeutic regimes, and their efficacy in treating diabetic wounds. The role of polymeric wound dressings loaded with bioactive compounds, and their in vitro and in vivo performance in diabetic wound treatment are also reviewed.

The wound healing effect of botanicals and pure natural substances used in in vivo models

Repairing the wound is a multistep process that includes the spatial and temporal synchronization of a different range of cell types to increase the speed of wound contraction, the proliferation of epithelial cells, and collagen formation. The need for proper management of acute wounds to be cured and not turned into chronic wounds is a significant clinical challenge. The traditional practice of medicinal plants in many regions of the world has been used in wound healing since ancient times. Recent scientific research introduced evidence of the efficacy of medicinal plants, their phyto-components, and the mechanisms underlying their wound-repairing activity. This review aims to briefly highlight the wound-curing effect of different plant extracts and purely natural substances in excision, incision, and burn experimental animal models with or without infection of mice, rats (diabetic and nondiabetic), and rabbits in the last 5 years. The in vivo studies represented reliable evidence of how powerful natural products are in healing wounds properly. They have good scavenging activity against Reactive oxygen species (ROS) and anti-inflammatory and antimicrobial effects that help in the process of wound healing. It is evident that incorporating bioactive natural products into wound dressings of bio- or synthetic polymers in nanofiber, hydrogel, film, scaffold, and sponge forms showed promising results in different phases of the wound-curing process of haemostasis, inflammation, growth, re-epithelialization, and remodelling.

Targeting matrix metalloproteases in diabetic wound healing

Chronic inflammation participates in the progression of multiple chronic diseases, including obesity, diabetes mellitus (DM), and DM related complications. Diabetic ulcer, characterized by chronic wounds that are recalcitrant to healing, is a serious complication of DM tremendously affecting the quality of life of patients and imposing a costly medical burden on society. Matrix metalloproteases (MMPs) are a family of zinc endopeptidases with the capacity of degrading all the components of the extracellular matrix, which play a pivotal part in healing process under various conditions including DM. During diabetic wound healing, the dynamic changes of MMPs in the serum, skin tissues, and wound fluid of patients are in connection with the degree of wound recovery, suggesting that MMPs can function as essential biomarkers for the diagnosis of diabetic ulcer. MMPs participate in various biological processes relevant to diabetic ulcer, such as ECM secretion, granulation tissue configuration, angiogenesis, collagen growth, re-epithelization, inflammatory response, as well as oxidative stress, thus, seeking and developing agents targeting MMPs has emerged as a potential way to treat diabetic ulcer. Natural products especially flavonoids, polysaccharides, alkaloids, polypeptides, and estrogens extracted from herbs, vegetables, as well as animals that have been extensively illustrated to treat diabetic ulcer through targeting MMPs-mediated signaling pathways, are discussed in this review and may contribute to the development of functional foods or drug candidates for diabetic ulcer therapy. This review highlights the regulation of MMPs in diabetic wound healing, and the potential therapeutic ability of natural products for diabetic wound healing by targeting MMPs.

Phytochemicals, Antioxidant, Anti-inflammatory Studies, and Identification of Bioactive Compounds Using GC-MS of Ethanolic Novel Polyherbal Extract

Hyperglycemia is the hallmark of diabetes, which is a collection of related metabolic disorders. Over time, diabetes can cause a variety of problems, including cardiovascular disease, nephropathy, neuropathy, and retinopathy. Ethanolic novel polyherbal extract (PHE) was prepared by mixing equal amounts of the following ingredients: Terminalia chebula Retz. (TC), Terminalia bellerica Roxb. (TB), Berberis aristata DC. (BA), Nyctanthes arbostratis L. (NA), Premna integrifolia L. (PI), and Andrographis paniculata Nees. (AP). Analysis of PHE results revealed phytochemicals like glycosides, flavonoids, alkaloids, tannins, phytosterols, and saponins. The aim of the study was to prepare an ethanolic extract of PHE using the cold maceration technique, and identify bioactive molecules from gas chromatography-mass spectrometry (GC-MS) analysis, and evaluate biological responses by using in vitro studies like antioxidant and anti-inflammatory activity. PHE was found to contain a total of 35 phytochemicals in GC-MS of which 22 bioactive compounds were obtained in good proportion. There are a few new ones, including 2-buten-1-ol, 2-ethyl-4-(2, 2, 3-trimethyl-3-cyclopenten-1-yl (17.22%), 1, 2, 5, 6-tetrahydrobenzonitrile (4.26%), 4-piperidinamine, 2, 2, 6, 6-tetramethyl-(0.07%), undecanoic acid, 5-chloro-, chloromethyl ester (0.41%), are identified. Antioxidant activity was estimated using EC₅₀ values of 392.143 µg/ml, which were comparable to the standard value of EC₅₀ 310.513 µg/ml obtained using DPPH. Antioxidant activity was estimated with EC₅₀ 392.143 µg/ml, comparable to standard EC₅₀ 310.513 µg/ml using DPPH. In vitro anti-inflammatory potential was found with IC₅₀ of 91.449 µg/ml, comparable to standard IC₅₀ 89.451 µg/ml for membrane stabilization and IC₅₀ of 36.940 µg/ml, comparable to standard IC₅₀ 35.723 µg/ml for protein denaturation assays. As a result, the findings of this study show an enrichment of bioactive phytochemicals that can be used to investigate biological activity. To better understand how diabetes receptors work, in silico studies like docking could be carried out.

Herbal Products and Their Active Constituents for Diabetic Wound Healing-Preclinical and Clinical Studies: A Systematic Review

The purpose of this review is to provide verified data on the current knowledge acquired in preclinical and clinical studies regarding topically used herbal products and their active constituents (formulations and dressings) with diabetic wound healing activity. Moreover, herbal products and their active constituents used for diabetic wound infections, and various cellular and molecular mechanisms of their actions will also be described. The electronic databases were searched for articles published from 2012 to 2022. Publications with oral or systemic administration of herbal products in diabetic wound healing, published before 2012, available only as an abstract, or in languages other than English were excluded from the study. The 59 articles comparing topically used herbal products in diabetic wound healing treatment versus control treatments (placebo or active therapy) were selected. Herbal products through different mechanisms of action, including antimicrobial, anti-inflammatory, antioxidant activity, stimulation of angiogenesis, production of cytokines and growth factors, keratinocytes, and fibroblast migration and proliferation may be considered as an important support during conventional therapy or even as a substitute for synthetic drugs used for diabetic wound treatment.

Advanced Drug Delivery System for Management of Chronic Diabetes Wound Healing

The diabetic wound is excessively vulnerable to infection because the diabetic wound suggests delayed and incomplete healing techniques. Presently, wounds and ulcers related to diabetes have additionally increased the medical burden. A diabetic wound can impair mobility, lead to amputations, or even death. In recent times, advanced drug delivery systems have emerged as promising approaches for enhancing the efficacy of wound healing treatments in diabetic patients. This review aims to provide an overview of the current advancements in drug delivery systems in managing chronic diabetic wound healing. This review begins by discussing the pathophysiological features of diabetic wounds, including impaired angiogenesis, elevated reactive oxygen species, and compromised immune response. These factors contribute to delayed wound healing and increased susceptibility to infection. The importance of early intervention and effective wound management strategies is emphasized. Various types of advanced drug delivery systems are then explored, including nanoparticles, hydrogels, transferosomes, liposomes, niosomes, dendrimers, and nanosuspension with incorporated bioactive agents and biological macromolecules are also utilized for chronic diabetes wound management. These systems offer advantages such as sustained release of therapeutic agents, improved targeting and penetration, and enhanced wound closure. Additionally, the review highlights the potential of novel approaches such as antibiotics, minerals, vitamins, growth factors gene therapy, and stem cell-based therapy in diabetic wound healing. The outcome of advanced drug delivery systems holds immense potential in managing chronic diabetic wound healing. They offer innovative approaches for delivering therapeutic agents, improving wound closure, and addressing the specific pathophysiological characteristics of diabetic wounds.

New Biological and Chemical Evidences of Two Lamiaceae Species (Thymbra capitata and Thymus sipyleus subsp. rosulans): In Vitro, In Silico and Ex Vivo Approaches

In this study, the methanolic and infusion extracts of two species, Thymbra capitata and Thymus sipyleus subsp. rosulans, were tested for their chemical composition and biological abilities (antioxidant, enzyme inhibitory and anti-inflammatory effects). The extracts yielded total phenolic and flavonoid contents in the range of 83.43-127.52 mg GAE/g and 9.41-46.34 mg RE/g, respectively. HPLC analysis revealed rosmarinic acid to be a major component of the studied extracts (15.85-26.43%). The best ABTS radical scavenging ability was observed in the methanol extract of T. capitata with 379.11 mg TE/g, followed by in the methanol extract of T. sipylus (360.93 mg TE/g). In the CUPRAC assay, the highest reducing ability was also found in the methanol extract of T. capitata with 802.22 mg TE/g. The phosphomolybdenum ability ranged from 2.39 to 3.61 mmol TE/g. In terms of tyrosinase inhibitory effects, the tested methanol extracts (83.18-89.66 mg KAE/g) were higher than the tested water extracts (18.74-19.11 mg KAE/g). Regarding the BChE inhibitory effects, the methanol extracts were active on the enzyme while the water extracts showed no inhibitory effect on it. Overall, the methanolic extracts showed better enzyme inhibition compared to the infusion extracts. Molecular docking also showed the selected exhibited potential binding affinities with all enzymes, with a preference for cholinesterases. Additionally, the extracts were effective in attenuating the LPS-induced increase in COX-2 and IL-6 gene expression in isolated colon, thus indicating promising anti-inflammatory effects. The preliminary results of this study suggest that these species are good natural sources of antioxidants and also provide some scope as enzyme inhibitors, most likely due to their bioactive contents such as phenolic acids, and thus can be exploited for different applications related to health promotion and disease prevention.

Surgical Outcomes of Regional Versus General Anesthesia in 203 Patients with Upper- and Lower-Extremity Amputation: A Retrospective Study from a Single Center in Turkey

BACKGROUND This retrospective study from a single center in Turkey aimed to compare the surgical results of regional anesthesia and general anesthesia in 203 patients with upper- and lower-extremity amputations. MATERIAL AND METHODS The study population consisted of patients who underwent extremity amputation between 2017 and 2021. Patients' demographic data, comorbidities, American Society of Anesthesiology (ASA) scores, amputated extremities, causes and extents of amputations, length of hospital stay, associated mortality/morbidity, and postoperative 90-day mortality data were comparatively analyzed between the groups created according to the anesthesia methods used in amputations. RESULTS The study consisted of 203 patients, of whom 80.8% were male. The most commonly used anesthesia method was peripheral nerve blocks (32.5%), followed by spinal anesthesia (31.5%), general anesthesia (31.0%), epidural anesthesia (2.0%), combined spinal-epidural anesthesia (1.5%), and sedo-analgesia (1.5%). Of the amputations performed, 37.0% were upper-extremity and 63.0% were lower-extremity. Peripheral nerve blocks were used most frequently in upper-extremity amputations (71.5%), and spinal anesthesia was used most frequently in lower-extremity amputations (48.9%). The mean length of hospital stay of the patients who underwent surgery under regional anesthesia methods was shorter than that of those who underwent general anesthesia (8.7±7.4 days vs 15.0±20.6 days). The mortality rate was 0.5% in the first 24 h, 0.5% in the next 48 h, and 4.9% in total. CONCLUSIONS The study findings demonstrated that performing extremity amputations under regional anesthesia techniques, particularly peripheral nerve blocks, reduces mortality/morbidity, the need for postoperative intensive care, mean length of stay in hospital, and hospital costs.

Wound healing in db/db mice with type 2 diabetes using non-contact exposure with an argon non-thermal atmospheric pressure plasma jet device

A non-thermal atmospheric pressure plasma jet (APPJ) may stimulate cells and tissues or result in cell death depending on the intensity of plasma at the target; therefore, we herein investigated the effects of non-thermal plasma under non-contact conditions on the healing of full-thickness wounds in diabetic mice (DM+ group) and normal mice (DM- group). A hydrogen peroxide colorimetric method and high performance liquid chromatography showed that APPJ produced low amounts of reactive oxygen and nitrogen species. Ten-week-old male C57BL/6j mice with normal blood glucose levels (DM- group) and 10-week-old male C57BLKS/J Iar-+Leprdb/+Leprdb mice (DM+ group) received two full-thickness cutaneous wounds (4 mm in diameter) on both sides of the dorsum. Wounds were treated with or without the plasma jet or argon gas for 1 minute and were then covered with a hydrocolloid dressing (Hydrocolloid), according to which mice were divided into the following groups: DM+Plasma, DM+Argon, DM+Hydrocolloid, DM-Plasma, DM-Argon, and DM-Hydrocolloid. Exudate weights, wound areas, and wound area ratios were recorded every day. Hematoxylin and eosin staining was performed to assess re-epithelialization and α-SMA immunohistological staining to evaluate the formation of new blood vessels. Non-thermal plasma under non-contact conditions reduced the production of exudate. Exudate weights were smaller in the DM+Plasma group than in the DM+Hydrocolloid and DM+Argon groups. The wound area ratio was smaller for plasma-treated wounds, and was also smaller in the DM+Plasma group than in the DM+Hydrocolloid and DM+Argon groups on days 1-21 (p<0.01). Wound areas were smaller in the DM-Plasma group than in the DM-Argon group until day 14 and differences were significant on days 1-5 (p<0.01). The percentage of re-epithelialization was significantly higher in the DM+Plasma group than in the DM+Argon and DM+Hydrocolloid groups (p<0.01). The number of new blood vessels that had formed by day 7 was significantly higher in the DM+Plasma group than in the DM+Hydrocolloid and DM+Argon groups (p<0.05). These results indicate that treatment with the current non-thermal plasma APPJ device under non-contact conditions accelerated wound healing in diabetic mice.

Bioactive functional collagen-oxidized pullulan scaffold loaded with polydatin for treating chronic wounds

Prolonged inflammation, elevated matrix metalloproteinases, hypoxia, decreased vascularization, increased oxidative stress, and bacterial infection are typical signs of chronic non-healing diabetic wounds. Any agent that improves one or all factors could offer enhanced opportunities for better healing of diabetic wounds. In this study, a polyphenol (polydatin) incorporated collagen scaffold was prepared using a biocompatible crosslinker, oxidized pullulan (Col-OxP3-Po), to treat diabetic wounds. The scaffolds were characterized using SEM, FTIR, antioxidant activity, in vitro and in vivo wound healing assay, gene expression, and immunohistopathological studies. Polydatin incorporated scaffold exhibited 75 % antioxidant activity, hemostatic and erythrocyte adhesion properties. FTIR results proved the incorporation of polydatin in the Col-OxP3-Po scaffold. They were also non-toxic to the 3 T3 fibroblasts with a viability of 93 % and good cell attachment. In vivo, normal and diabetic wound healing studies showed that the Col-OxP3-Po scaffold treated group healed on days 16 and 21. The histological and immunohistochemistry analyses of the granulation tissues showed improved epithelialization, angiogenesis and enhanced collagen deposition by modulating TGF-β3 and MMP - 9 gene expressions favorable for better healing. Thus, this scaffold could be a newer treatment strategy for chronic non-healing wounds.

Multifunctional and Smart Wound Dressings—A Review on Recent Research Advancements in Skin Regenerative Medicine

The healing of wounds is a dynamic function that necessitates coordination among multiple cell types and an optimal extracellular milieu. Much of the research focused on finding new techniques to improve and manage dermal injuries, chronic injuries, burn injuries, and sepsis, which are frequent medical concerns. A new research strategy involves developing multifunctional dressings to aid innate healing and combat numerous issues that trouble incompletely healed injuries, such as extreme inflammation, ischemic damage, scarring, and wound infection. Natural origin-based compounds offer distinct characteristics, such as excellent biocompatibility, cost-effectiveness, and low toxicity. Researchers have developed biopolymer-based wound dressings with drugs, biomacromolecules, and cells that are cytocompatible, hemostatic, initiate skin rejuvenation and rapid healing, and possess anti-inflammatory and antimicrobial activity. The main goal would be to mimic characteristics of fetal tissue regeneration in the adult healing phase, including complete hair and glandular restoration without delay or scarring. Emerging treatments based on biomaterials, nanoparticles, and biomimetic proteases have the keys to improving wound care and will be a vital addition to the therapeutic toolkit for slow-healing wounds. This study focuses on recent discoveries of several dressings that have undergone extensive pre-clinical development or are now undergoing fundamental research.

Antimicrobial Peptide-Tether Dressing Able to Enhance Wound Healing by Tissue Contact

No effective therapeutic dressings are currently available in the market that can prevent bacterial infection and simultaneously promote skin regeneration in diabetic patients. The lack of re-epithelization, prevalence of inflammation, and high risk of infection are hallmarks of non-healing wounds. Here, we have evaluated the antimicrobial and pro-regenerative effect of a relatively non-leaching LL37 peptide immobilized in polyurethane (PU)-based wound dressings (PU-adhesive-LL37 dressing). The PU-adhesive-LL37 (63 μg LL37NPs/cm²) dressing killed Gram-positive and Gram-negative bacteria in human serum without inducing bacterial resistance after 16 antimicrobial test cycles in contrast to commercially available dressings with the capacity to release antimicrobial Ag ions. Importantly, type II diabetic mice (db/db mice) treated with the PU-adhesive-LL37 dressing for different periods of time (6 or 14 days) showed enhanced wound healing and re-epithelialization (i.e., high keratin 14/5 levels) and lower macrophage infiltration in the wounds compared to animals treated with PU. The wounds treated with PU-adhesive-LL37 dressings showed also low expression of pro-inflammatory cytokines such as TNF-α and IL6 after 6 days of treatment, indicating that they act as an anti-inflammatory dressing. Additionally, PU-adhesive-LL37 dressings do not induce acute inflammatory responses in the peripheral blood mononuclear cells (PBMCs) after 3 days of exposure, in contrast to controls. Taken together, PU-adhesive-LL37NP dressings might prevent the bacterial infections and facilitate wound healing by tissue contact, inducing re-epithelialization and anti-inflammatory processes in diabetic conditions.

Influence of Tangeretin on the Exponential Regression of Inflammation and Oxidative Stress in Streptozotocin-Induced Diabetic Nephropathy

Diabetes is an amalgamation of metabolic disorders marked by hyperglycemia. Over time diabetes brings up several other complications with it like cardiovascular disease, retinopathy, neuropathy, and nephropathy. among which diabetic nephropathy (DN) is the one we are concerned about in the present study. Diabetes management requires following a healthy lifestyle with proper medication. Most of the anti-diabetic drugs available at present come with adverse side effects. Nature has provided us with several components that are anti-diabetic in nature which has fewer or no side effects and tangeretin is one among them. Tangeretin is a natural flavonoid abundantly present in orange peel and tangerines. Our study is designed to evaluate tangeretin, as an anti-diabetic medication especially for patients suffering from diabetic nephropathy. The procured healthy rats were first divided into four groups: the group I was maintained as healthy control and the others were subjected to the induction of diabetes by i.p. injection of streptozotocin (STZ) at the concentration of 55mg/kg b.wt .Then, the diabetic rats were further divided into three groups: group II was used as the diabetic control rats and the group III and group IV were administered with tangeretin (25mg/kg b.wt) and positive control drug metformin (150mg/kg b.wt) for 8 weeks. The body weight, blood glucose, and serum insulin levels were estimated at week 0 and week 8. Reactive oxygen species (ROS) inhibitory effect, antioxidant, antilipidemic, nephroprotective, and anti-inflammatory effects of tangeretin on the diabetic-induced rats were evaluated at the end of week 8 in addition to the histopathological assessment of the sections of the kidneys of the experimental rats. All the test results concluded that tangeretin was able to significantly decelerate the progression of DN in STZ-induced diabetic rats.

A Pilot Study to Explore a Correlation between Inflammatory Markers and the Wound Healing Rate in Diabetic Patients

Background and objectives: We examined whether there is a significant correlation between inflammatory markers and the wound healing rate (WHR) in diabetic patients. Materials and Methods: A total of 60 patients were divided into two groups depending on the completion of wound healing (WH) at 5 weeks: the early WH group (period of WH < 5 weeks; n = 27) and the late WH group (period of WH > 5 weeks; n = 33). The baseline characteristics and wound measurements were compared between the two groups. To identify the correlation between inflammatory markers (e.g., white blood cell counts (WBCs), serum C-reactive protein (CRP) levels and erythrocyte sedimentation rate (ESR)) and WHR, we performed a Pearson correlation analysis. Results: The WHR was 8.06 ± 4.02 mm2/day in the early WH group and 2.71 ± 0.88 mm2/day in the late group. This difference reached statistical significance (p < 0.001). Moreover, WBC counts were significantly higher and serum levels of CRP and ESR were significantly lower in the early WH group than in the late group (p = 0.027, 0.036 and 0.043, respectively). Conclusions: Our results indicate that WBC as well as serum CRP and ESR levels have a significant correlation with WHR in diabetic patients.

Evaluation of the Performance of a ZnO-Nanoparticle-Coated Hydrocolloid Patch in Wound Healing

Hydrocolloid dressings are an important method for accelerating wound healing. A combination of a hydrocolloid and nanoparticles (NPs), such as gold (Au), improves the wound healing rate, but Au-NPs are expensive and unable to block ultraviolet (UV) light. Herein, we combined zinc oxide nanoparticles (ZnO-NPs) with hydrocolloids for a less expensive and more effective UV-blocking treatment of wounds. Using Sprague–Dawley rat models, we showed that, during 10-day treatment, a hydrocolloid patch covered with ZnO-NPs (ZnO-NPs-HC) macroscopically and microscopically stimulated the wound healing rate and improved wound healing in the inflammation phase as shown by reducing of pro-inflammatory cytokines (CD68, IL-8, TNF-α, MCP-1, IL-6, IL-1β, and M1) up to 50%. The results from the in vitro models (RAW264.7 cells) also supported these in vivo results: ZnO-NPs-HCs improved wound healing in the inflammation phase by expressing a similar level of pro-inflammatory mediators (TNF-α and IL-6) as the negative control group. ZnO-NPs-HCs also encouraged the proliferation phase of the healing process, which was displayed by increasing expression of fibroblast biomarkers (α-SMA, TGF-β3, vimentin, collagen, and M2) up to 60%. This study provides a comprehensive analysis of wound healing by measuring the biomarkers in each phase and suggests a cheaper method for wound dressing.

Fabrication of chitosan/PVP/dihydroquercetin nanocomposite film for in vitro and in vivo evaluation of wound healing

The high cost of wound healing treatment, the slow recovery of wounds, and the uncertainty of being affected by the body's physiological activities constitute a serious burden on public health. In this work, we report the preparation and characterization of chitosan (CS), PVP, and dihydroquercetin (DHQ) nanofiber film used as wound excipients, as well as in vivo and in vitro evaluations, and verify that the film is effective in wounds. The results show that the prepared film has good morphology, thermal stability and hydrophilicity. In vitro studies have shown that it has antibacterial activity against S.aureus and E.coli, and the DPPH free radical scavenging rate proves that the fiber film has antioxidant activity. MTT cytotoxicity test proved that the film is non-toxic to Hacat cells. Animal experiments have proved that wounds treated with CS-PVP-DHQ nanofiber film heal faster. This article also studied the composite nanofiber film by inducing autophagy pathway and increasing the expression of pan-keratin, vascular endothelial growth factor VEGF and CD31 to promote wound healing. Therefore, the nanofiber film herein show great potential in wound healing applications.

Polymer-Based Wound Dressing Materials Loaded with Bioactive Agents: Potential Materials for the Treatment of Diabetic Wounds

Diabetic wounds are severe injuries that are common in patients that suffer from diabetes. Most of the presently employed wound dressing scaffolds are inappropriate for treating diabetic wounds. Improper treatment of diabetic wounds usually results in amputations. The shortcomings that are related to the currently used wound dressings include poor antimicrobial properties, inability to provide moisture, weak mechanical features, poor biodegradability, and biocompatibility, etc. To overcome the poor mechanical properties, polymer-based wound dressings have been designed from the combination of biopolymers (natural polymers) (e.g., chitosan, alginate, cellulose, chitin, gelatin, etc.) and synthetic polymers (e.g., poly (vinyl alcohol), poly (lactic-co-glycolic acid), polylactide, poly-glycolic acid, polyurethanes, etc.) to produce effective hybrid scaffolds for wound management. The loading of bioactive agents or drugs into polymer-based wound dressings can result in improved therapeutic outcomes such as good antibacterial or antioxidant activity when used in the treatment of diabetic wounds. Based on the outstanding performance of polymer-based wound dressings on diabetic wounds in the pre-clinical experiments, the in vivo and in vitro therapeutic results of the wound dressing materials on the diabetic wound are hereby reviewed.

Allotransplantation of ascorbic acid-treated fibroblasts improves healing of excisional cutaneous wound in diabetic rats

The purpose of this study was to evaluate the effects of ascorbic acid (AA)-treated fibroblasts transplantation on excisional diabetic wound healing. An excisional wound was created between the shoulders of streptozotocin-induced diabetic rats. On day three, 1 ml of PBS, ‎1 × 10⁶ ‎intact homologous fibroblasts, and ‎1 × 10⁶ ‎ fibroblasts treated with 50 μM AA were injected subcutaneously around the wound edges in control, treatment-1 and treatment-2 groups, respectively. In the sham group, the wound was left intact. Wound area was measured by planimetry. On day 15, samples were harvested for histopathological examination and hydroxyproline content. Wound area in treatment-1 and - 2 groups was ‎significantly decreased compared to other groups, on days 11 and 15. The hydroxyproline content was significantly lower in the control group compared to the other groups. Histopathology revealed significant increases in the number of neovessels, macrophages, lymphocytes and fibroblasts in the treatment-2 group compared to the other groups. Trichrome staining showed the highest level of collagen deposition and orientation in the treatment-2 group. In conclusion, allotransplantation of ‎50 μM ‎ AA-treated fibroblasts ‎could result in progressive healing and improved reparative indices of excisional dermal wound in diabetic rats.

The signaling pathways of traditional Chinese medicine in promoting diabetic wound healing

ETHNOPHARMACOLOGICAL RELEVANCE

The diabetic wound is one of the common chronic complications of diabetes, which seriously affects patients' quality of life and even causes disability and death. Traditional Chinese medicine (TCM) is a unique and precious resource in China, which has a good curative effect and safety. At present, it has been found that Chinese herbal compounds and effective active ingredients can effectively promote diabetic wound healing, and its mechanism needs to be further studied. Signaling pathways are involved in the pathogenesis and progression of diabetic wounds, which is one of the main targets for the pathologic mechanism of diabetic wounds and the pharmacological research of therapeutic drugs.

AIM OF THE REVIEW

This study has been carried out to reveal the classical signaling pathways and potential targets by the action of TCM on diabetic wound healing and provides evidence for its clinical efficacy.

MATERIALS AND METHODS

"diabetic wound", "diabetic foot ulcer", "traditional Chinese medicine", "natural plant" and "medicinal plant", were selected as the main keywords, and various online search engines, such as PubMed, Web of Science, CNKI and other publication resources, were used for searching literature.

RESULTS

The results showed that TCM could regulate the signaling pathways to promote diabetic wound healing, such as Wnt, Nrf2/ARE, MAPK, PI3K/Akt, NF-κB, Notch, TGF-β/Smad, HIF-1α/VEGF, which maintaining inflammatory interaction balance, inhibiting oxidative stress and regulating abnormal glucose metabolism.

CONCLUSION

The effect of TCM on diabetic wound healing was reflected in multiple levels and multiple pathways. It is envisaged to carry out further research from precision-targeted therapy, provide ideas for screening the core target of TCM in treating diabetic wounds and create modern innovative drugs based on this target.

Novel therapeutic targets for diabetes-related wounds or ulcers: an update on preclinical and clinical research

INTRODUCTION

Diabetes-related wounds, particularly diabetes-related foot ulcers, are mainly caused by lack of foot sensation and high plantar tissue stress secondary to peripheral neuropathy, ischemia secondary to peripheral artery disease, and dysfunctional wound healing. Current management of diabetes-related wounds involves the offloading of high foot pressures and the treatment of ischemia through revascularization. Despite these treatments, the global burden of diabetes-related wounds is growing, and thus, novel therapies are needed. The normal wound healing process is a coordinated remodeling process orchestrated by fibroblasts, endothelial cells, phagocytes, and platelets, controlled by an array of growth factors. In diabetes-related wounds, these coordinated processes are dysfunctional. The past animal model and human research suggest that prolonged wound inflammation, failure to adequately correct ischemia, and impaired wound maturation are key therapeutic targets to improve diabetes-related wound healing.

AREAS COVERED

This review summarizes recent preclinical and clinical research on novel diabetes-related wound treatments. Animal models of diabetes-related wounds and recent studies testing novel therapeutic agents in these models are described. Findings from clinical trials are also discussed. Finally, challenges to identifying and implementing novel therapies are described.

EXPERT OPINION

Given the growing volume of promising drug therapies currently under investigation, it is expected within the next decade, that diabetes-related wound treatment will be transformed.

Topical application of metformin accelerates cutaneous wound healing in streptozotocin-induced diabetic rats

BACKGROUND

Diabetic chronic wound, which is one of the diabetic complications caused by hyperglycemia, characterized by prolonged inflammation has become one of the most serious challenges in the clinic. Hyperglycemia during diabetes not only causes prolonged inflammation and delayed wound healing but also modulates the activation of nuclear factor-kappa B (NF-κB) and the expression of matrix metalloproteinases (MMPs). Although metformin is the oldest oral antihyperglycemic drug commonly used for treating type 2 diabetes, few studies have explored the molecular mechanism of its topical effect on wound healing. Therefore, we aimed to investigate the molecular effects of topical metformin application on delayed wound healing, which's common in diabetes.

METHODS AND RESULTS

In this context, we created a full-thickness excisional wound model in Wistar albino rats and, investigated NF-κB p65 DNA-binding activity and expression levels of RELA (p65), MMP2 and MMP9 in wound samples taken on days 0, 3, 7, and 14 from diabetic/non-diabetic rats treated with metformin and saline. As a result of our study, we showed that topically applied metformin accelerates wound healing by suppressing NF-κB p65 activity and diminishing the expression of MMP2 and MMP9.

CONCLUSIONS

Diabetic wounds treated with metformin healed even faster than those in the control group that mimicked standard wound healing.

Irisin restores high glucose-induced cell injury in vascular endothelial cells by activating Notch pathway via Notch receptor 1

Diabetic foot ulcers (DFU) are a vascular complication of diabetes mellitus (DM). It has been confirmed that irisin is closely related to DM. However, the effect of irisin on DFU is obscure and needs further study. After human umbilical vein endothelial cell lines (HUVECs) were treated with different concentrations' irisin, normal glucose, high glucose (HG), HG plus irisin-high (H) or sh-Notch1, cell biological behaviors, LDH, and VEGFA were detected by cell function experiments. Apoptosis- and Notch pathway-related protein levels were evaluated by Western blot. Irisin has no cytotoxicity, and irisin-H elevated cell viability and inhibited apoptosis and LDH level in HG-induced HUVECs. Meanwhile, irisin-H restored HG-repressed migration and angiogenesis in HUVECs. Irisin-H inhibited apoptosis-related protein levels and promoted VEGFA and Notch pathway-related protein levels in HG-treated HUVECs. Additionally, sh-Notch1 reversed the protective effect of irisin-H in HG-treated HUVECs. Irisin restores HG-induced cell injury and angiogenesis in HUVECs by activating Notch pathway via Notch1.

Improvement of Cutaneous Wound Healing via Topical Application of Heat-Killed Lactococcus chungangensis CAU 1447 on Diabetic Mice

Cutaneous wound healing comprises a complex systemic network. Probiotics, naturally extracted substances, medicine, and chemical compounds have been used for wound healing, but the application of postbiotics as therapeutic agents has yet to be explored. Our study shows potential beneficial effects of heat-killed Lactococcus chungangensis CAU 1447 on type 1 diabetic mice. The postbiotic strain significantly decreased the skin wound size. The activity of myeloperoxidase secreted from neutrophils also decreased. The molecular mechanism of wound healing was adjusted by important mediators, growth factors, chemokines, and cytokines. These elements regulated the anti-inflammatory activity and accelerated wound healing. To determine the role of the postbiotic in wound repair, we showed a similar taxonomic pattern as compared to the diabetic mice using skin microbiome analysis. These findings demonstrated that heat-killed Lactococcus chungangensis CAU 1447 had beneficial effects on wound healing and can be utilized as postbiotic therapeutic agents.

Angelica dahurica and Rheum officinale Facilitated Diabetic Wound Healing by Elevating Vascular Endothelial Growth Factor

Traditional Chinese medicine (TCM) provides alternative treatment choices for diabetic wounds. The aim of this study was to evaluate the effects of Angelica dahurica and Rheum officinale (ARE) on diabetic wounds and its underlying action mechanism. A total of 36 healthy male Sprague-Dawley rats were randomly divided into three groups: diabetes mellitus (DM) rats treated with ARE (DM-ARE), DM rats treated with 0.9% saline (DM-NS), and non-DM rats treated with 0.9% saline (NDM-NS). DM was induced by intraperitoneal administration of 40 mg/kg of streptozotocin after a 2-week high-fat diet feeding. After excisional skin wounds and treatments, the remaining wound area (RWA) in each group was measured. The RWA in the DM-NS group (69.60% ± 2.35%) was greater than that in the DM-ARE (55.70% ± 1.85%) and NDM-NS groups (52.50% ± 2.77%) on day 6. Besides, the DM-ARE group showed higher vascular endothelial growth factor (VEGF), higher inducible nitric oxide synthase (iNOs), higher [Formula: see text]-smooth muscle actin ([Formula: see text]-SMA), and lower nuclear factor kappa-light-chain-enhancer of activated B cell (NF-[Formula: see text]B) expression in the wound skin tissue. These results showed that treatment with ARE shifted the recovery pattern of diabetic rats to the pattern of nondiabetic rats, indicating that ARE may improve wound healing in diabetic conditions.

Sustained Release of Insulin-Like Growth Factor-1 from Bombyx mori L. Silk Fibroin Delivery for Diabetic Wound Therapy

The goals of this study are to develop a high purity patented silk fibroin (SF) film and test its suitability to be used as a slow-release delivery for insulin-like growth factor-1 (IGF-1). The release rate of the SF film delivering IGF-1 followed zero-order kinetics as determined via the Ritger and Peppas equation. The release rate constant was identified as 0.11, 0.23, and 0.09% h^-1 at 37 °C for SF films loaded with 0.65, 6.5, and 65 pmol IGF-1, respectively. More importantly, the IGF-1 activity was preserved for more than 30 days when complexed with the SF film. We show that the IGF-1-loaded SF films significantly accelerated wound healing in vitro (BALB/3T3) and in vivo (diabetic mice), compared with wounds treated with free IGF-1 and an IGF-1-loaded hydrocolloid dressing. This was evidenced by a six-fold increase in the granulation tissue area in the IGF-1-loaded SF film treatment group compared to that of the PBS control group. Western blotting analysis also demonstrated that IGF-1 receptor (IGF1R) phosphorylation in diabetic wounds increased more significantly in the IGF-1-loaded SF films group than in other experimental groups. Our results suggest that IGF-1 sustained release from SF films promotes wound healing through continuously activating the IGF1R pathway, leading to the enhancement of both wound re-epithelialization and granulation tissue formation in diabetic mice. Collectively, these data indicate that SF films have considerable potential to be used as a wound dressing material for long-term IGF-1 delivery for diabetic wound therapy.

Effects of Methanolic Extract Based-Gel From Saudi Pomegranate Peels With Enhanced Healing Potential on Excision Wounds in Diabetic Rats

Introduction: Current study was designed to evaluate the wound healing activity of a Saudi pomegranate peel extract on excision wound healing in experimentally induced diabetes in rats. Methodology: Animals were divided into three groups: diabetic excision wound with no treatment, diabetic excision wound with gel alone and diabetic excision wound with Saudi pomegranate peel extract in gel. Animals were monitored for clinical signs, weekly body weight, morbidity and mortality during entire study period. The efficacy parameters evaluated were percent wound contraction, Hydroxyproline content, estimation of Transforming Growth Factor ß1 (TGF-ß1), Vascular Endothelial Growth Factor (VEGF), and Epidermal Growth Factor (EGF) in wound lysates by ELISA, mRNA expression of TGF-ß1, VEGF, and EGF in wound lysates by qPCR, Estimation of nitric oxide (NO) and NO synthase (NOS) in Wound Lysates and histopathology of skin for reepithelization, neovascularization, and inflammation. Results: The Saudi pomegranate peel extract in gel (5.0 g extract per 100 g gel) showed significant wound healing activity when compared to the vehicle control [p < 0.05] following 21 days of treatment. Animals in the control and treatment groups were apparently normal through the study with no significant differences in body weights between groups. Expression of mRNA of TGFβ1, EGF and VEGF in wounds was the highest on day 14 post treatment 4.3, 3.5 and 0.9 fold higher respectively in the treatment group when compared to vehicle control, and on day 21, the values were 0.12, 0.3 and 0.83, respectively. No statistically significant differences were observed in TGF-ß1 levels in wounds on days 4, 7, 14 and 21 post treatment when compared to the vehicle control (p > 0.05). Significantly higher levels of VEGF were observed in treatment group on day 7 and 21 when compared to vehicle control (p < 0.05). Significantly higher levels of EGF were observed in treatment group on day 7 and 21 when compared to vehicle control (p < 0.05). Mean hydroxyproline levels were higher in treatment group on days 4 and 7 when compared to vehicle control. NO levels in treatment group were significantly lower on days 7, 14 and 21 when compared to vehicle control (p < 0.05). NOS activity in treatment group were significantly lower on days 4 and 7 when compared to vehicle control (p < 0.05). Histopathological changes in skin wound in the treatment group were consistent with wound healing when compared to the vehicle group. Conclusion: This study's findings suggest that topical application of SPPE gel effectively enhanced wound healing in experimentally induced diabetic conditions.

Graphene oxide-cellulose nanocomposite accelerates skin wound healing

The usage of materials with the potential to accelerate wound healing is a great benefit for patients and health care systems. This study evaluated the impact of using graphene oxide (GO)-cellulose nanocomposite on skin wound healing via in vitro and in vivo investigations. The nanomaterial was synthesized and characterized. Cytocompatibility performance of the GO-cellulose was investigated through in vitro testing based on MTT and live/dead assays by EA.hy926 human endothelial cells (ECs). Additionally, the effect of GO-cellulose on induced wound scratch model using EA.hy926 ECs was investigated. Finally, the therapeutic effect of GO-cellulose was evaluated in vivo after the creation of two full-thickness wounds in the dorsum of rats (8 mm diameter). These wounds were randomly placed into two groups, the control group (10 wounds) and the GO-cellulose group (10 wounds), and monitored for gross and histopathological changes at 7 and 21 days after wound induction. MTT and Live/Dead assays showed excellent GO-cellulose cytocompatibility, whereas no difference in ECs viability was observed after culturing using conditioned media. GO-cellulose nanocomposite enhanced cell migration in the in vitro wound scratch assay. As compared to the control group, the GO-cellulose nanocomposite group's wound healing process was promoted in the in vivo rat skin wounds. Interestingly, wound re-epithelization and neovascularization were significantly accelerated in the GO-cellulose-treated rats. Furthermore, thick granulation tissue formation and intense collagen deposition were found in the GO-cellulose group. These findings showed that GO-cellulose has a promoting effect on skin wound healing, suggesting its promising and potential application in tissue regeneration.

Wound Healing and Antioxidant Evaluations of Alginate from Sargassum ilicifolium and Mangosteen Rind Combination Extracts on Diabetic Mice Model

A diabetic foot ulcer is an open wound that can become sore and frequently occurs in diabetic patients. Alginate has the ability to form a hydrophilic gel when in contact with a wound surface in diabetic patients. Xanthones are the main compounds of mangosteen rind and have antibacterial and anti-inflammatory properties. The purpose of this research was to evaluate the wound healing and antioxidants assay with a combination of alginate from S. ilicifolium and mangosteen rind combination extracts on a diabetic mice model. The characterization of alginate was carried out by size exclusion chromatography with multiple angle laser light scattering (SEC-MALLS) and thermogravimetric analysis (TGA). The M/G ratio of alginate was calculated by using proton nuclear magnetic resonance (1H NMR). The antioxidant activity of mangosteen rind and the combination extracts was determined using the DPPH method. The observed parameters were wound width, number of neutrophils, macrophages, fibrocytes, fibroblasts, and collagen densities. The 36 male mice were divided into 12 groups including non-diabetic control (NC), diabetes alginate (DA), alginate–mangosteen (DAM), and diabetes control (DC) groups in three different groups by a histopathology test on skin tissue. The treatment was carried out for 14 days and mice were evaluated on Days 3, 7, and 14. The SEC-MALLS results showed that the molecular weight and dispersity index (Ð) of alginate were 2.77 × 104 Dalton and 1.73, respectively. The M/G ratio of alginate was 0.77 and described as single-stage decomposition based on TGA. Alginate, mangosteen rind extract, and their combination were divided into weak, medium, and strong antioxidant, respectively. The treatment of the DA and DAM groups showed a decrease in wound width and an increase in the number of fibrocytes, fibroblasts, and macrophages. The number of neutrophils decreased while the percentage of collagen densities increased for all the considered groups.

Fabrication of In Situ Layered Hydrogel Scaffold for the Co-delivery of PGDF-BB/Chlorhexidine to Regulate Proinflammatory Cytokines, Growth Factors, and MMP-9 in a Diabetic Skin Defect Albino Rat Model

Diabetes mellitus (DM)-associated impairments in wound healing include prolonged inflammation, the overexpression of matrix metalloproteases (MMPs), and low levels of growth factors at the wound site. To this end, a layer-by-layer scaffold (S_L-B-L) made of cross-linked silk fibroin and hyaluronic acid is developed to deliver chlorhexidine, an antimicrobial agent and an MMP-9 inhibitor, along with the PDGF-BB protein. S_L-B-L exhibited highly porous morphology. Diabetic rats treated with S_L-B-L demonstrated an early wound closure, a fully reconstructed epithelial layer by 14 days, and reduced levels of IL-6, TNF-α, TGF-β1, and MMP-9. Interestingly, S_L-B-L treatment increased angiogenesis, the bioavailability of collagen, DNA content, and VEGF-A levels. Furthermore, enhanced keratinocyte-fibroblast interaction along with ordered collagen deposition was observed in S_L-B-L-treated rats. Most interestingly, when compared with a clinically used scaffold SEESKIN+, S_L-B-L outperformed in promoting wound healing in a diabetic rat model by regulating the inflammation while delivering growth factor and the MMP-9 inhibitor.

Topical Application of Ozonated Oils for the Treatment of MRSA Skin Infection in an Animal Model of Infected Ulcer

Simple Summary

Methicillin-resistant Staphylococcus aureus is often found in skin lesions infected in particular in diabetic foot ulcers, in which the prevalence can reach 40%. Clinical methicillin-resistant Staphylococcus aureus is generally resistant to most classes of antibiotics and therefore it is necessary to develop new antimicrobial agents. Ozone has a recognized bactericidal activity and has been widely used as a clinical therapeutic agent for chronic wounds, such as ulcers and other injuries, due to its ability to heal wounds. This is a preliminary study that reports the effectiveness of ozonated oils on the eradication of skin infection in vivo. The study provides further insights into the antibacterial effect of ozone in infected skin ulcers in diabetic rats and also, the potential wound healing effect of ozonated oils. Furthermore, this is the first study investigating the efficacy of ozone in the eradication of diabetic foot ulcers infected by methicillin-resistant Staphylococcus aureus. Our results indicate that topical application of ozonated oils infected skin in rats have significant antimicrobial activity as well as wound healing capacity. Achieving the healing of infected diabetic foot wounds has become a challenge and ozonated oils may be used to treat these infections.

Abstract

Diabetic foot ulcers are a common cause of morbidity in diabetic patients. One of the main pathogens found in these ulcers is methicillin-resistant Staphylococcus aureus (MRSA). MRSA often carries resistance to several classes of antibiotics and their infections are becoming harder to treat. Therefore, new alternatives are urgently needed. Thus, this study aimed to investigate the capacity of topical ozonated oil application on the treatment of early-stage skin infected with MRSA in an animal model. Ozonated oil was prepared from a mixture of oils subjected to a gas stream of O₂/O₃ mixture. Sixteen Wistar rats were inoculated by an intradermic injection of MRSA suspension, producing an abscess lesion. After 3 days, the skin epidermis was removed to open the wound. Group 1 received an application of oil mixture without ozone treatment and Group 2 received an application of ozonated oil. After the treatment period, skin was collected, colony-forming units (CFU) of bacteria were quantified and the histological analysis of the skin was carried out. Skin samples from the control 1 and 2 had a bacterial load was of 1.1 × 10⁵ and 5.7 × 10³ CFU/mL, respectively. Group 2 showed better wound healing from mild to moderate epidermal regeneration. Topical application of ozonated vegetable oil in MRSA-infected skin in rats showed a small reduction of the bacterial load and better wound healing.