Cellular and Molecular Processes in Wound Healing

Cytotoxicity evaluation of microbial sophorolipids and glucolipids using normal human dermal fibroblasts (NHDF) in vitro

Fibroblasts are considered a key player in the wound healing process. Although this cellular family is constituted by several distinct subtypes, dermal fibroblasts are crucial thanks to their ability to secrete pro-regenerative growth factors, extracellular matrix (ECM) proteins and their immune and anti-inflammatory role. Sophorolipids (SL), sophorosides (SS) and glucolipids (G), mono-unsaturated (C18:1) or saturated (C18:0), glycolipids derived from microbial fermentation of wild type or engineered yeast Starmerella bombicola, constitute a novel sustainable class of bio-based chemicals with interesting physicochemical characteristics, which allow them to form soft diverse structures from hydrogels to vesicles, micelles or complex coacervates with potential interest in skin regeneration applications. In this study, we first tested the cytocompatibility of a broad set of molecules from this family on normal human dermal fibroblasts (NHDF). Our results show that, up to an upper threshold (0.1 % w/v), the microbial glycolipids (SL-C18:1, G-C18:1, SSbola-C18:1, SL-C18:0 and G-C18:0) under study were able to sustain cell growth. Furthermore, we selected the least cytotoxic glycolipids (SL-C18:1, SSbola-C18:1, SL-C18:0) to study their potential to promote wound healing by measuring the gene expression of several key skin regeneration markers (i.e. collagen, elastin, transforming growth factor β, fibroblast growth factor …) using qPCR. Unfortunately, none of these glycolipids modulated the gene expression of molecules involved in tissue repair. However, this study aims to encourage the community to test this novel class of molecules for novel high-end biomedical applications.

Importance

Biosurfactants prepared by microbial fermentation are natural amphiphiles of growing importance, with the goal of replacing synthetic surfactants in commercial formulations. However, their cytotoxicity profile is still poorly known, especially for new molecules like single-glucose lipids or bolaform sophorolipids. This wants to contribute to all those applications, which could be developed with biosurfactants in contact with the skin (cosmetics, wound healing). We test the cytotoxicity of five structurally-related molecules (C18:1 and C18:0 sophorolipids, C18:1 and C18:0 single-glucose lipids, C18:1 di-sophoroside) against normal human dermal fibroblasts (NHDF) and evaluate the metabolic activity of the least toxic among them. To the best of our knowledge, cytotoxicity of these molecules, and of microbial biosurfactants in general, was never tested against NHDF.

Advancement of Nanomaterials- and Biomaterials-Based Technologies for Wound Healing and Tissue Regenerative Applications

Patients and healthcare systems face significant social and financial challenges due to the increasing number of individuals with chronic external and internal wounds that fail to heal. The complexity of the healing process remains a serious health concern, despite the effectiveness of conventional wound dressings in promoting healing. Recent advancements in materials science and fabrication techniques have led to the development of innovative dressings that enhance wound healing. To further expedite the healing process, novel approaches such as nanoparticles, 3D-printed wound dressings, and biomolecule-infused dressings have emerged, along with cell-based methods. Additionally, gene therapy technologies are being harnessed to generate stem cell derivatives that are more functional, selective, and responsive than their natural counterparts. This review highlights the significant potential of biomaterials, nanoparticles, 3D bioprinting, and gene- and cell-based therapies in wound healing. However, it also underscores the necessity for further research to address the existing challenges and integrate these strategies into standard clinical practice.

γ-Oryzanol: A nutrient-rich ingredient for promoting wound healing

γ-Oryzanol (Orz) is a powerful antioxidant found in rice bran and oil, known for its numerous health benefits. Nevertheless, its precise impact on skin wound healing remains largely unexplored. This research focuses on comprehensively examining the ability of Orz to promote tissue repair through laboratory-based and animal model experiments. The research further examines its antimicrobial activity and its role in promoting wound healing through anti-inflammatory effects. To evaluate the effect of Orz on tissue repair, scratch assays performed in vitro were used to analyze its impact on cellular migration. An in vivo experiment utilizing a rat skin wound excision model was carried out to investigate wound contraction rates and analyze histological modifications. The granulation tissue from a dead space wound model was examined to assess the levels of inflammatory mediators, free radicals, and antioxidant activity. The findings of the study demonstrated Orz improves cellular viability while facilitating the proliferation and migration of NIH-3T3 cells. It further promotes the generation of growth factors, such as fibroblast growth factor 21 and transforming growth factor-β. Moreover, Orz exhibited significant antimicrobial activity against various pathogens commonly found in wounds. An ointment with 10 % Orz showed significant effectiveness in promoting wound healing, as indicated by notable wound contraction observed on the 14th day after surgery. Histological analysis demonstrated that the application of 10 % Orz ointment resulted in remarkable tissue repair, heightened fibroblast proliferation, and improved formation of new blood vessels. The application of Orz ointment was also found to elevate interleukin-10 levels, reduce tumor necrosis factor-α levels and ED-1-immunopositive cells, and enhance antioxidant enzyme activity, thereby mitigating oxidative damage in healing tissues throughout the initial stages of tissue repair. These results indicate that Orz holds significant promise for application in the treatment of surface wounds.

Regenerative effect of lyophilized dental follicle mesenchymal stem cells and platelet-rich fibrin in skin wounds in geriatric and young rats

The aim of this study was to investigate the regenerative effect of lyophilized dental follicle mesenchymal stem cells (DF-MSCs) combined with rat platelet-rich fibrin (PRF) on geriatric skin wounds. Human DF-MSCs which were isolated from the wisdom teeth of healthy donors and PRF were mixed and incubated in a 37 °C incubator for 1-2 h containing 1 million cells in 150 mg PRF. The mixture was suspended in a freeze-drying solution and then lyophilized. Wounds were created on the back skin of Wistar albino rats using a 6 mm punch. Lyophilized DF-MSCs, PRF, or PRF + DF-MSCs were applied to the wounds of rats. On the 15th day, the wound area was histopathologically evaluated in rats. Blood samples from rats were analyzed for total antioxidant status (TAOS), and inflammatory cytokine levels using ELISA. In both young and geriatric rats treated with lyophilized PRF + DF-MSCs, wound area began to significantly decrease from the 10th day compared to the untreated group (p < 0.05). Histopathological examination revealed that in the lyophilized PRF + DF-MSCs treated groups, epithelial integrity and scarless healing significantly increased compared to the untreated groups (p < 0.05). There were no significant differences in TAOS, total oxidant status (TOS), tumor necrosis factor (TNF), interleukin-6 (IL6), and hydroxyproline levels in serum samples from young rats on the 15th day. In geriatric rats, hydroxyproline (HYPS) levels were increased in the DF-MSC and PRF + DF-MSC groups (p < 0.01), TNF was significantly elevated in PRF geriatric group and IL6 was increased in the PRF group compared to the control group (p = 0.01). Lyophilized PRF + DF-MSCs, which is a shelf-stable and ready-to-use product, hold promise, especially for traumatic wounds in geriatric individuals with longer healing times.

Mechanistic insights of diabetic wound: Healing process, associated pathways and microRNA-based delivery systems

Wounds that represent one of the most critical complications can occur in individuals suffering from diabetes mellitus, and results in the need for hospitalisation and, in severe cases, require amputation. This condition is primarily characterized by infections, persistent inflammation, and delayed healing processes, which exacerbate the overall health of the patients. As per the standard mechanism, signalling pathways such as PI3K/AKT, HIF-1, TGF-β, Notch, Wnt/β-Cat, NF-κB, JAK/STAT, TLR, and Nrf2 play major roles in inflammatory, proliferative and remodelling phases of wound healing. However, dysregulation of the above pathways has been seen during the healing of diabetic wounds. MicroRNAs (miRNAs) are small, non-coding RNAs that regulate the expression of various genes and signalling pathways which are associated with the process of wound healing. In the past few years, there has been a great deal of interest in the potential of miRNAs as biological agents in the management of a number of disorders. These miRNAs have been shown to modulate expression of genes involved in the healing process of wounds. There have been previous reviews pertaining to clinical trials examining miRNAs in several disorders, but only a few clinical studies have examined involvement of miRNAs in healing of wounds. Considering the therapeutic promise, there are several obstacles concerning their instabilities and inefficient delivery into the target cells. Therefore, this review is an attempt to discuss precise roles of signalling pathways and miRNAs in different phases of wound healing, and their aberrant regulation in diabetic wounds, particularly. It has also compiled a range of delivery mechanisms as well as an overview of the latest findings pertaining to miRNAs and associated delivery systems for improved healing of diabetic wounds.

Exosome laden sprayable thermo-sensitive polysaccharide-based hydrogel for enhanced burn wound healing

Severe burns pose significant threats to patient well-being, characterized by pain, inflammation, bacterial infection, and extended recovery periods. While exosome-loaded hydrogels have demonstrated considerable promise in wound healing, current formulations often fall short of achieving optimal therapeutic efficacy for burn wounds due to challenges related to their adaptability to wound shape and limited anti-bacterial capabilities. In this study a novel exosome laden sprayable thermosensitive polysaccharide-based hydrogel (ADA-aPF127@LL18/Exo) comprising alginate dialdehyde (ADA) and aminated Pluronic F127 (aPF127) was fabricated via Schiff base reaction. ADA-aPF127@LL18/Exo exhibited sustained release of exosome and enhanced antibacterial efficacy. Furthermore, the biological assessments displayed excellent biocompatibility and enhanced in vitro cell proliferation and migration. In a deep partial thickness burn model, ADA-aPF127@LL18/Exo significantly augmented wound healing processes by accelerating epithelialization, promoting granulation tissue formation and collagen deposition, inducing hair follicle regeneration, effectively mitigating inflammatory responses, and facilitating enhanced neovascularization. In conclusion, ADA-aPF127@LL18/Exo represents a highly promising therapeutic dressing for the treatment of deep burns, exhibiting multifaceted properties conducive to efficient wound management.

Empirical use, phytochemical, and pharmacological effects in wound healing activities of compounds in Diospyros leaves: A review of traditional medicine for potential new plant-derived drugs

ETHNOPHARMACOLOGICAL RELEVANCE

Wound healing extracts' activity is increasingly being studied in the field of traditional medicine. Among medicinal plants, Diospyros is known to have healing effects on wounds, along with activities such as anti-biofilm, anti-inflammatory, antibacterial, antioxidant, and regulation of the immune system. However, the current use of the leaves could be more optimal, and the scientific basis needs to be improved.

AIM OF THIS REVIEW

This review aimed to critically examine the literature on the traditional use and bioactive metabolites of several Diospyros species, demonstrating the significant potential in wound healing, antibacterial, anti-biofilm, regulatory effect on the immune system, anti-inflammatory, and antioxidant activities. The critical analysis was conducted to provide robust perspectives and recommendations for future studies on the use of Diospyros potential resources of wound healing material, including related activities.

MATERIALS AND METHODS

Exploratory studies on Diospyros species over the past 20 years were examined, with a focus on general information, practical use, secondary metabolite, and pharmacological activities related to wound healing. Data were meticulously collected from scientific databases including Scopus, ScienceDirect, Web of Science, Taylor & Francis, Google Scholar, PubMed as well as various botanical and biodiversity sources. Furthermore, manual searches were conducted to ensure comprehensive coverage. Reference manager software was used to manage articles and remove duplicates, then the gathered data were summarized and verified, ensuring the thoroughness and validity of the review process.

RESULTS

The results showed that Diospyros leaves have great potential to be harnessed as herbal medications, evidenced by both scientific findings and community uses. Various substances, including flavonoids, coumarins, tannins, terpenoids, steroids, lignans, quinones, and secoiridoids were identified. Chemical compound investigations in both in vivo and in vitro studies of Diospyros leaves reported wound healing activity, as well as antibacterial, anti-inflammatory, anti-biofilm, antioxidant, and immunomodulatory properties.

CONCLUSION

The review highlights the traditional uses and bioactive metabolites of Diospyros species in wound healing, identifying various beneficial compounds such as flavonoids and tannins. These compounds demonstrate various therapeutic effects, including antibacterial, anti-biofilm, anti-inflammatory, antioxidant, and immunomodulatory activities. Diospyros leaf extracts have a favorable safety profile, but further studies, including in vivo investigations and clinical trials, are necessary to confirm their efficacy and safety for clinical applications. Diospyros leaf extracts have significant potential for the development of wound healing substances due to the wide range of bioactivities targeting various stages of wound healing.

Lovastatin and Resveratrol Synergistically Improve Wound Healing and Inhibit Bacterial Growth

Wound healing is a complex physiological process, with scarring and infection caused by Staphylococcus aureus and Pseudomonas aeruginosa being the most common complications. The reutilization of known medications has received increased attention for their role in cell function as small molecules. Examples of these include lovastatin, a cholesterol-lowering agent, and resveratrol, which have multiple biological properties. Both molecules have been reported to improve wound healing and possess antibacterial properties, with conflicting results. The wound-healing capabilities of human mesenchymal stem cells were evaluated after exposure to lovastatin, resveratrol, and their combination through scratch test, migrations assay, and qPCR. Protein docking was performed to assess the lovastatin/resveratrol combination as potential wound-healing targets. AlamarBlue assay was used to determine cell viability. Additionally, the impact of lovastatin and resveratrol combination to inhibit the growth of S. aureus and P. aeruginosa was tested using broth microdilution test and checkerboard assay to determine synergism. The combination of lovastatin 0.1 μM and resveratrol 0.1 μM synergistically improved wound healing and demonstrated an additive effect against S. aureus and P. aeruginosa, presenting potential antibacterial applications.

Effects of low-level laser irradiation on canine fibroblasts

Low-level laser (LLL) therapy is a well-known noninvasive treatment that stimulates fibroblasts to improve wound healing. LLL can improve fibroblast proliferation and migration without causing toxicity. The present study aimed to evaluate the effects of two laser wavelengths at different irradiation times on canine fibroblasts. Fibroblasts were isolated from canine oral mucosa. After seeding for 24 hr, the fibroblasts were irradiated using the Erchonia® EVL dual-diode laser at wavelengths of 405 nm (5 mW) and 640 nm (7.5 mW) with irradiation times of 120, 360, and 1,800 sec. The proliferating and viability cells were evaluated 24 hr after laser irradiation. Wound closure rates were calculated at 0, 24, and 48 hr after laser irradiation. Parameters, including proliferation cell, cell viability, and cell migration, tended to be higher in the 360-sec group (405 nm) and 120-sec group (640 nm) than in other groups. Our findings suggest that LLL therapy at wavelengths of 405 and 640 nm with an irradiation time of 120-360 sec (0.26-0.51 J/cm2) can stimulate the proliferation and migration of canine fibroblasts. This finding may contribute to a better understanding of the beneficial role of LLL stimulation in canine wound healing.

Strontium nitrate-dopped zinc oxide-loaded alginate gels with gentamicin for improved wound healing

Wound dressing development is an area of active research. Traditional dressings lack antibacterial activity, biocompatibility, and tissue regeneration. Alginate is a heavily investigated polymer employed as wound dressings and can be combined with a wide range of additives. Herein, we report the preparation of alginate gel using the crosslinking technique as potential wound dressing, with insight investigation of the influence of employing single, two, or three cross-linkers: Strontium (Sr), zinc oxide (ZnO), and gentamicin sulfate. Rheology was used to confirm the gel's preparation, where the samples' viscosity curves show decreased viscosity with increased shear rate, indicating pseudoplastic flow. The linear viscoelastic region shows constant G' and G" within the sample structure. In this study, we used three gels with different mixtures of ingredients: Gels A, B, and C contain sodium alginate (1% w/v) and 0.5 mL of Sr nitrate (4% w/v). However, Gels B and C contain 0.25 mL of ZnO (0.5% w/v). Gel C also includes 0.1 mL of gentamicin (1% w/v). The study examined the effectiveness of Gel A, B, and C on wound healing, calculating the reduction of wound area after seven, 14, and 20 days of a single topical treatment. Gel A, B, and C significantly reduced wound area, while Gel B and C showed a significant reduction. The zone of inhibition was used to detect the gels' efficacy against microorganisms. The study found zinc deposition in the liver and bone, with Gel B and C showing higher levels. The study also found significant overexpression of MIP α and MIP β in tissues and downregulation of CCL2, IL8, and TGF β, explaining wound healing with minimal scar formation.

Comparison of dermal and eschar fibroblasts in full skin equivalents

Full-thickness burn wounds pose significant problems, demanding specialised therapies to avoid complications and promote recovery. Eschar tissue, which forms in response to severe burns, contains viable fibroblasts, which migrate from the surrounding tissue in response to burn injury and exhibit a myofibroblast phenotype. The goal of this study was to characterise eschar-derived fibroblasts and examine their use for engineered in vitro full skin equivalents in comparison to normal dermal fibroblasts, which were harvested from non-injured skin. Microarray analysis indicated that eschar fibroblasts differ from dermal fibroblasts in various biological processes including inflammation, extracellular matrix formation, cell migration and differentiation. Skin equivalents with eschar fibroblasts showed similarities to those generated using normal dermal fibroblasts in terms of epidermis and dermis formation. However, in contrast to dermal fibroblast-based full skin equivalents, eschar fibroblast-based equivalents exhibited macroscopic contractile behaviour. In addition, eschar fibroblasts-based equivalents demonstrated higher alpha-smooth muscle actin expression on mRNA and protein levels. In conclusion, our findings suggest that eschar fibroblasts-based full skin equivalents hold promise as a platform to study burn wound environments as eschar fibroblasts are clinically more relevant fibroblasts and able to mimic certain aspects of the challenging wound environment in vitro.

Mast cells and wound healing: Still an open question

Mast cells, which originate from the bone marrow, possess the ability to secrete a diverse array of active molecules. These molecules include mediators (histamine, heparin), which have been identified for decades and are stored in specific granules, as well as small molecules generated instantaneously in response to stimulation (membrane lipid derivatives, nitric oxide), and a multitude of multifunctional cytokines that are secreted constitutively. Activated mast cells participate in the regulation of the local immune response and exert control over critical events of inflammation and healing with the assistance of a vast array of mediators. The involvement of these cell types in inflammatory states suggests that mast cells may function as sentinels that activate local immune processes in response to various types of stimuli and the entry of antigens. Moreover, due to their proximity to nerve fibers and reactivity to a variety of neurotransmitters, mast cells are among the cells that may facilitate local neuroimmune interactions. With this in mind, it is necessary to consider their participation in the repair of injuries in both acute and chronic conditions.

Beyond antibiotics: mesenchymal stem cells and bacteriophages-new approaches to combat bacterial resistance in wound infections

Wound management is a major global health problem. With the rising incidence of diabetic wounds, accidents, and other injuries, the demand for prompt wound treatment has become increasingly critical. Millions of people suffer from serious, large wounds resulting from major accidents, surgeries, and wars. These wounds require considerable time to heal and are susceptible to infection. Furthermore, chronic wounds, particularly in elderly and diabetic patients, often require frequent medical interventions to prevent complications. Consequently, wound management imposes a significant economic burden worldwide. The complications arising from wound infections can vary from localized issues to systemic effects. The most severe local complication of wound infection is the non-healing, which results from the disruption of the wound-healing process. This often leads to significant pain, discomfort, and psychological trauma for the patient. Systemic complications may include cellulitis, osteomyelitis, and septicemia. Mesenchymal stem cells are characterized by their high capacity for division, making them suitable candidates for the treatment of tissue damage. Additionally, they produce antimicrobial peptides and various cytokines, which enhance their antimicrobial activity. Evidence shows that phages are effective in treating wound-related infections, and phage therapy has proven to be highly effective for patients when administered correctly. The purpose of this article is to explore the use of bacteriophages and mesenchymal stem cells in wound healing and infection management.

Molecular Biomarkers in Cutaneous Photodynamic Therapy: A Comprehensive Review

BACKGROUND/OBJECTIVES

Photodynamic therapy (PDT) is widely utilized in dermatology for the treatment of various skin conditions. Despite its effectiveness, the exact biomolecular changes underlying therapeutic outcomes remain only partially understood. This review, through a transversal approach, aims to provide an in-depth exploration of molecular biomarkers involved in PDT, evaluate its underlying mechanisms, and examine how these insights can contribute to enhanced treatment protocols and personalized therapy approaches.

METHODS

A narrative review of the literature was conducted, targeting peer-reviewed articles and clinical trials that focus on PDT and its molecular biomarker effects on dermatological conditions. The databases searched included PubMed, Scopus, and Web of Science, and the inclusion criteria encompassed original research articles, systematic reviews, and meta-analyses in English.

RESULTS

PDT effectively reduces the expression of critical biomarkers such as p53, Cyclin D1, and Ki-67 in AK and other cancerous lesions, leading to reduced cell proliferation and increased apoptosis. Additionally, PDT promotes extracellular matrix remodeling and stimulates collagen production, which has a rejuvenating effect on the skin and a promising role in the treatment of chronic wounds.

CONCLUSIONS

PDT represents a powerful and versatile treatment option for various dermatological conditions due to its ability to target cellular pathways involved in proliferation and apoptosis. Further research into optimizing treatment parameters and combining PDT with other targeted therapies may enhance patient outcomes, reduce resistance, and pave the way for more individualized therapeutic approaches in dermatology.

Natural polymer nanofiber dressings for effective management of chronic diabetic wounds: A comprehensive review

Diabetic wounds present a chronic challenge in effective treatment. Natural polymer nanofiber dressings have emerged as a promising solution due to their impressive biocompatibility, biodegradability, safety, high specific surface area, and resemblance to the extracellular matrix. These qualities make them ideal materials with excellent biological properties and cost-effectiveness. Additionally, they can effectively deliver therapeutic agents, enabling diverse treatment effects. This review offers a comprehensive overview of natural polymer-based nanofibers in diabetic wound dressings. It examines the characteristics and challenges associated with diabetic wounds and the role of natural polymers in facilitating wound healing. The review highlights the preparation, mechanism, and applications of various functional dressings composed of natural polymer nanofibers. Furthermore, it addresses the main challenges and future directions in utilizing natural polymer nanofibers for diabetic wound treatment, providing valuable insights into effective wound management for diabetic patients.

Deciphering the Wound-Healing Potential of Collagen Peptides and the Molecular Mechanisms: A Review

Collagen peptides have been reported to display various bioactivities and high bioavailability. Recently, increasing evidence has revealed the excellent wound-healing activity of collagen peptides, but their molecular mechanisms remain incompletely elucidated. This review systematically evaluates the therapeutic efficacy of collagen peptides from diverse sources based on various wound models. Furthermore, the structure-activity relationships of collagen peptides and wound-healing mechanisms are discussed and summarized. Characterized by their low molecular weight and abundant imino acids, collagen peptides facilitate efficient absorption by the body to deliver nutrition throughout the wound-healing process. The specific mechanism of collagen peptide for wound healing is mainly through up-regulation of related cytokines and participation in the activation of relevant signaling pathways, such as TGF-β/Smad and PI3K/Akt/mTOR, which can promote cell proliferation, angiogenesis, collagen synthesis and deposition, re-epithelialization, and ECM remodeling, ultimately achieving the effect of wound healing. Collagen peptides can offer a potential therapeutic approach for treating incision and excision wounds, mucosal injuries, burn wounds, and pressure ulcers, improving the efficiency of wound healing by about 10%-30%. The present review contributes to understanding of the wound-healing potential of collagen peptides and the underlying molecular mechanisms.

Inflammation-Modulating Biomedical Interventions for Diabetic Wound Healing: An Overview of Preclinical and Clinical Studies

A diabetic wound exemplifies the challenge of chronic, nonhealing wounds. Elevated blood sugar levels in diabetes profoundly disrupt macrophage function, impairing crucial activities such as phagocytosis, immune response, cell migration, and blood vessel formation, all essential for effective wound healing. Moreover, the persistent presence of pro-inflammatory cytokines and reactive oxygen species, coupled with a decrease in anti-inflammatory factors, exacerbates the delay in wound healing associated with diabetes. This review emphasizes the dysfunctional inflammatory responses underlying diabetic wounds and explores preclinical studies of inflammation-modulating bioactives and biomaterials that show promise in expediting diabetic wound healing. Additionally, this review provides an overview of selected clinical studies employing biomaterials and bioactive molecules, shedding light on the gap between extensive preclinical research and limited clinical studies in this field.

Liver Fluke-Derived Molecules Accelerate Skin Repair Processes in a Mouse Model of Type 2 Diabetes Mellitus

Chronic nonhealing wounds, such as diabetic ulcers, are among the most serious complications of diabetes mellitus. Consequently, the search for new therapeutic strategies remains highly relevant. Based on our previous data on acute wounds, bioactive molecules derived from the liver fluke Opisthorchis felineus hold promise as a novel approach to wound healing. The aim of this study was to investigate the wound-healing properties of excretory-secretory products (ESP) and inactivated eggs of O. felineus in a model of type 2 diabetes mellitus. Two-month-old mice of the BKS.Cg + Leprdb/+Leprdb/OlaHsd (db/db) strain were inflicted with superficial wounds of 5 mm in diameter. Mouse groups included several controls (methylcellulose as the vehicle and human recombinant PDGF as the positive control) and specific-treatment groups (ESP and inactivated O. felineus eggs). Histopathological, immunohistochemical, and RT-PCR studies using markers for M1/M2 polarization, angiogenesis, and extracellular matrix remodeling were carried out. Additionally, an image analysis of Masson's trichrome-stained skin sections was performed. The proliferation of HaCaT cells under ESP and egg treatment was also assessed. The present study reveals a significant increase in the percentage of wound healing in ESP- and egg-treated groups, which significantly exceeded the control values after 14 days. Wound treatment with either ESP or worm eggs resulted in (i) a reduction in inflammation with a canonical M1-to-M2 polarization shift, (ii) the modulation of the vascular response, and (iii) dermal extracellular matrix remodeling. All results are comparable to those of the positive control group treated with PDGF. This study also reveals that ESP, but not O. felineus eggs, stimulated keratinocyte proliferation in vitro. The results indicate the high wound-healing potential of liver fluke bioactive molecules and open prospects for further research on these new promising therapeutic approaches.

Silk Fibroin Nanofibers: Advancements in Bioactive Dressings through Electrospinning Technology for Diabetic Wound Healing

BACKGROUND

Non-healing diabetic wounds represent a significant clinical challenge globally, necessitating innovative approaches in drug delivery to enhance wound healing. Understanding the pathogenesis of these wounds is crucial for developing effective treatments. Bioactive dressings and polymeric nanofibers have emerged as promising modalities, with silk biomaterials gaining attention for their unique properties in diabetic wound healing.

PURPOSE OF REVIEW

The purpose of this review is to examine the challenges and innovations in treating non-healing diabetic wounds, emphasizing the global burden and the need for effective solutions. This review explores the complex mechanisms of wound healing in diabetes and evaluates the therapeutic potential of bioactive dressings and polymeric nanofibers. Special focus is given to the application of silk biomaterials, particularly silk fibroin, for wound healing, detailing their properties, mechanisms, and clinical translation. This review also describes various nanofiber fabrication methods, especially electrospinning technology, and presents existing evidence on the effectiveness of electrospun silk fibroin formulations.

RECENT FINDINGS

Recent advancements highlight the potential of silk biomaterials in diabetic wound healing, owing to their biocompatibility, mechanical strength, and controlled drug release properties. Electrospun silk fibroin-based formulations have shown promising results in preclinical and clinical studies, demonstrating accelerated wound closure and tissue regeneration.

SUMMARY

Non-healing diabetic wounds present a significant healthcare burden globally, necessitating innovative therapeutic strategies. Bioactive dressings and polymeric nanofibers, particularly silk-based formulations fabricated through electrospinning, offer promising avenues for enhancing diabetic wound healing. Further research is warranted to optimize formulation parameters and validate efficacy in larger clinical trials.

Exploring the Wound Healing Potential of Hispidin

BACKGROUND

Hispidin, a polyphenol component mainly derived from the medicinal mushroom species Phellinus and Inonotus, shows promise for biomedical applications, yet its potential in wound healing remains largely unexplored. This research investigates the wound healing effects of hispidin through in vitro and in vivo experiments, while also evaluating its antimicrobial properties and safety profile.

METHODS

In vitro scratch assays were conducted to evaluate the impact of hispidin on the migration of NIH-3T3 cells. The wound healing potential of hispidin was assessed in rats using excision wounds, dead space wounds, and linear incisions, treated with various topical ointments including a simple ointment, 2.5% (w/w) and a 5% (w/w) hispidin ointment, and a 0.2% (w/w) nitrofurazone ointment, administered at 0.2 g daily for 14 days.

RESULTS

Hispidin demonstrated antimicrobial properties and was particularly effective against Staphylococcus epidermidis. Hispidin enhanced NIH-3T3 cell viability, and promoted wound closure in scratch assays, correlating with increased levels of FGF21, TGF-β1, EGF, and VEGF. In excision wound models, the 5% (w/w) hispidin ointment improved wound contraction, epithelialization, tissue regeneration, fibroblast activity, and angiogenesis. In the granulation tissue from dead space wound models, hispidin reduced pro-inflammatory cytokines (TNF-α, IL-6, IL-1β) and lipid peroxidation, while increasing anti-inflammatory cytokines (IL-10) and antioxidant activities (SOD, GPx, CAT), along with connective tissue markers like hydroxyproline, hexosamine, and hexuronic acid. Hispidin also enhanced wound breaking strength in incision models. Acute dermal toxicity studies indicated no adverse effects at 2000 mg/kg.

CONCLUSIONS

These findings highlight hispidin's potential in wound care, demonstrating its antimicrobial, regenerative, and safety properties.

Advancements in employing two-dimensional nanomaterials for enhancing skin wound healing: a review of current practice

The two-dimensional nanomaterials are characterized by their ultra-thin structure, diverse chemical functional groups, and remarkable anisotropic properties. Since its discovery in 2004, graphene has attracted significant scientific interest due to its potential applications in various fields, including electronics, energy systems, and biomedicine. In medicine, graphene is used for designing smart drug delivery systems, especially for antibiotics, and biosensing. Skin trauma is a prevalent dermatological condition that increasingly contributes to morbidities and mortalities, thus representing a significant health burden. During tissue damage, rapid skin repair is crucial to prevent blood loss and infection. Therefore, drugs used for skin trauma must possess antimicrobial and anti-inflammatory properties. Two-dimensional (2D) nanomaterials possess remarkable physical, chemical, optical, and biological characteristics due to their uniform shape, increased surface area, and surface charge. Graphene and its derivatives, transition-metal dichalcogenides (TMDs), black phosphorous (BP), hexagonal boron nitride (h-BN), MXene, and metal-organic frameworks (MOFs) are among the commonly used 2D nanomaterials. Moreover, they exhibit antibacterial and anti-inflammatory properties. This review presents a comprehensive discussion of the clinical approaches employed for wound healing treatment and explores the applications of commonly used 2D nanomaterials to enhance wound healing outcomes.

The rat as an animal model in chronic wound research: An update

The increasing global prevalence of chronic wounds underscores the growing importance of developing effective animal models for their study. This review offers a critical evaluation of the strengths and limitations of rat models frequently employed in chronic wound research and proposes potential improvements. It explores these models in the context of key comorbidities, including diabetes, venous and arterial insufficiency, pressure-induced blood flow obstruction, and infections. Additionally, the review examines important wound factors including age, sex, smoking, and the impact of anesthetic and analgesic drugs, acknowledging their substantial effects on research outcomes. A thorough understanding of these variables is crucial for refining animal models and can provide valuable insights for future research endeavors.

The Combination of Chitosan-Based Biomaterial and Cellular Therapy for Successful Treatment of Diabetic Foot-Pilot Study

Diabetic foot ulceration is one of the most common complications in patients treated for diabetes mellitus. The presented pilot study describes the successful treatment of diabetic ulceration of the heel with ongoing osteomyelitis in a 39-year-old patient after using a combination of modified chitosan-based biomaterial in combination with autologous mesenchymal stem cells isolated from bone marrow and dermal fibroblasts. The isolated population of bone marrow mesenchymal stem cells fulfilled all of the attributes given by the International Society for Stem Cell Research, such as fibroblast-like morphology, the high expression of positive surface markers (CD29: 99.1 ± 0.4%; CD44: 99.8 ± 0.2% and CD90: 98.0 ± 0.6%) and the ability to undergo multilineage differentiation. Likewise, the population of dermal fibroblasts showed high positivity for the widely accepted markers collagen I, collagen III and vimentin, which was confirmed by immunocytochemical staining. Moreover, we were able to describe newly formed blood vessels shown by angio CT and almost complete closure of the skin defect after 8 months of the treatment.

Multifunctional Molybdenum-Based Nanoclusters Engineered Gelatin Methacryloyl as In Situ Photo-Cross-Linkable Hybrid Hydrogel Dressings for Enhanced Wound Healing

Skin injuries and wounds present significant clinical challenges, necessitating the development of advanced wound dressings for efficient wound healing and tissue regeneration. In this context, the advancement of hydrogels capable of counteracting the adverse effects arising from undesirable reactive oxygen species (ROS) is of significant importance. This study introduces a hybrid hydrogel with rapid photocuring and excellent conformability, tailored to ameliorate the hostile microenvironment of damaged skin tissues. The hybrid hydrogel, composed of photoresponsive Gelatin Methacryloyl (GelMA) and Molybdenum-based nanoclusters (MNC), exhibits physicochemical characteristics conductive to skin regeneration. In vitro studies demonstrated the cytocompatibility and ROS-responsive behavior of the MNC/GelMA hybrid hydrogels, confirming their ability to promote human dermal fibroblasts (HDF) functions. The incorporation of MNC into GelMA not only enhances HDF adhesion, proliferation, and migration but also shields against oxidative damage induced by hydrogen peroxide (H2O2). Notably, in vivo evaluation in murine full-thickness skin defects revealed that the application of hybrid hydrogel dressings led to reduced inflammation, accelerated wound closure, and enhanced collagen deposition in comparison to control groups. Significantly, this study introduced a convenient approach to develop in situ ROS-scavenging hydrogel dressings to accelerate the wound healing process without the need for exogenous cytokines or medications. We consider that the nanoengineering approach proposed herein offers potential possibilities for the development of therapeutic hydrogel dressings addressing various skin-related conditions.

Decellularized Umbilical Cord as a Scaffold to Support Healing of Full-Thickness Wounds

The umbilical cord is a material that enhances regeneration and is devoid of age-related changes in the extracellular matrix (ECM). The aim of this work was to develop a biodegradable scaffold from a decellularized human umbilical cord (UC-scaffold) to heal full-thickness wounds. Decellularization was performed with 0.05% sodium dodecyl sulfate solution. The UC-scaffold was studied using morphological analysis methods. The composition of the UC-scaffold was studied using immunoblotting and Fourier transform infrared spectroscopy. The adhesion and proliferation of mesenchymal stromal cells were investigated using the LIVE/DEAD assay. The local reaction was determined by subcutaneous implantation in mice (n = 60). A model of a full-thickness skin wound in mice (n = 64) was used to assess the biological activity of the UC-scaffold. The proposed decellularization method showed its effectiveness in the umbilical cord, as it removed cells and retained a porous structure, type I and type IV collagen, TGF-β3, VEGF, and fibronectin in the ECM. The biodegradation of the UC-scaffold in the presence of collagenase, its stability during incubation in hyaluronidase solution, and its ability to swell by 1617 ± 120% were demonstrated. Subcutaneous scaffold implantation in mice showed gradual resorption of the product in vivo without the formation of a dense connective tissue capsule. Epithelialization of the wound occurred completely in contrast to the controls. All of these data suggest a potential for the use of the UC-scaffold.

A Systematic Review of Human Amnion Enhanced Cartilage Regeneration in Full-Thickness Cartilage Defects

Cartilage defects present a significant challenge in orthopedic medicine, often leading to pain and functional impairment. To address this, human amnion, a naturally derived biomaterial, has gained attention for its potential in enhancing cartilage regeneration. This systematic review aims to evaluate the efficacy of human amnion in enhancing cartilage regeneration for full-thickness cartilage defects. An electronic search was conducted on MEDLINE-PubMed, Web of Science (WoS), and the Scopus database up to 27 December 2023 from 2007. A total of 401 articles were identified. After removing 125 duplicates and excluding 271 articles based on predetermined criteria, only 5 articles remained eligible for inclusion in this systematic review. All five eligible articles conducted in vivo studies utilizing rabbits as subjects. Furthermore, analysis of the literature reveals an increasing trend in the frequency of utilizing human amnion for the treatment of cartilage defects. Various forms of human amnion were utilized either alone or seeded with cells prior to implantation. Histological assessments and macroscopic observations indicated usage of human amnion improved cartilage repair outcomes. All studies highlighted the positive results despite using different forms of amnion tissues. This systematic review underscores the promising role of human amnion as a viable option for enhancing cartilage regeneration in full-thickness cartilage defects, thus offering valuable insights for future research and clinical applications in orthopedic tissue engineering.

Neuroimmunomodulatory effect of Nitric Oxide on chronic wound healing after photodynamic therapy

Neuroimmunomodulation is the capacity of the nervous system to regulate immune processes. The existence of neurotransmitter receptors in immune cells enables this phenomenon to take place. Neuronal mediators possess the capacity to direct and control several occurrences during the wound healing process. Nitric oxide (NO) functions as a neuromodulator, playing a crucial role in the regulation of vascular tone and blood pressure with antimicrobial properties. Photodynamic therapy has been shown to augment the function of immune cells involved in the healing process of venous leg ulcers. Nitric oxide can be secreted into the extracellular environment by these cells. In lesions treated with PDT, the synthesis of iNOs (the enzyme that releases NO) increased, as demonstrated by the experimental results. Therefore the significance of PDT in enhancing the clinical condition of the lesion is thus highlighted.

Unlocking the Power of Light on the Skin: A Comprehensive Review on Photobiomodulation

Photobiomodulation (PBM) is a procedure that uses light to modulate cellular functions and biological processes. Over the past decades, PBM has gained considerable attention for its potential in various medical applications due to its non-invasive nature and minimal side effects. We conducted a narrative review including articles about photobiomodulation, LED light therapy or low-level laser therapy and their applications on dermatology published over the last 6 years, encompassing research studies, clinical trials, and technological developments. This review highlights the mechanisms of action underlying PBM, including the interaction with cellular chromophores and the activation of intracellular signaling pathways. The evidence from clinical trials and experimental studies to evaluate the efficacy of PBM in clinical practice is summarized with a special emphasis on dermatology. Furthermore, advancements in PBM technology, such as novel light sources and treatment protocols, are discussed in the context of optimizing therapeutic outcomes and improving patient care. This narrative review underscores the promising role of PBM as a non-invasive therapeutic approach with broad clinical applicability. Despite the need for further research to develop standard protocols, PBM holds great potential for addressing a wide range of medical conditions and enhancing patient outcomes in modern healthcare practice.

Hesperidin - loaded PVA/alginate hydrogel: targeting NFκB/iNOS/COX-2/TNF-α inflammatory signaling pathway

Introduction

Skin injuries represent a prevalent form of physical trauma, necessitating effective therapeutic strategies to expedite the wound healing process. Hesperidin, a bioflavonoid naturally occurring in citrus fruits, exhibits a range of pharmacological attributes, including antimicrobial, antioxidant, anti-inflammatory, anticoagulant, and analgesic properties. The main objective of the study was to formulate a hydrogel with the intention of addressing skin conditions, particularly wound healing.

Methods

This research introduces a methodology for the fabrication of a membrane composed of a Polyvinyl alcohol - Sodium Alginate (PVA/A) blend, along with the inclusion of an anti-inflammatory agent, Hesperidin (H), which exhibits promising wound healing capabilities. A uniform layer of a homogeneous solution comprising PVA/A was cast. The process of crosslinking and the enhancement of hydrogel characteristics were achieved through the application of gamma irradiation at a dosage of 30 kGy. The membrane was immersed in a Hesperidin (H) solution, facilitating the permeation and absorption of the drug. The resultant system is designed to deliver H in a controlled and sustained manner, which is crucial for promoting efficient wound healing. The obtained PVA/AH hydrogel was evaluated for cytotoxicity, antioxidant and free radical scavenging activities, anti-inflammatory and membrane stability effect. In addition, its action on oxidative stress, and inflammatory markers was evaluated on BJ-1 human normal skin cell line.

Results and Discussion

We determined the effect of radical scavenging activity PVA/A (49 %) and PVA/AH (87%), the inhibition of Human red blood cell membrane hemolysis by PVA/AH (81.97 and 84.34 %), hypotonicity (83.68 and 76.48 %) and protein denaturation (83.17 and 85.8 %) as compared to 250 μg/ml diclofenac (Dic.) and aspirin (Asp.), respectively. Furthermore, gene expression analysis revealed an increased expression of genes associated with anti-oxidant and anti-inflammatory properties and downregulated TNFα, NFκB, iNOS, and COX2 by 67, 52, 58 and 60%, respectively, by PVA/AH hydrogel compared to LPS-stimulated BJ-1 cells. The advantages associated with Hesperidin can be ascribed to its antioxidant and anti-inflammatory attributes. The incorporation of Hesperidin into hydrogels offers promise for the development of a novel, secure, and efficient strategy for wound healing. This innovative approach holds potential as a solution for wound healing, capitalizing on the collaborative qualities of PVA/AH and gamma irradiation, which can be combined to establish a drug delivery platform for Hesperidin.

AESIS-1, a Rheumatoid Arthritis Therapeutic Peptide, Accelerates Wound Healing by Promoting Fibroblast Migration in a CXCR2-Dependent Manner

In patients with autoimmune disorders such as rheumatoid arthritis (RA), delayed wound healing is often observed. Timely and effective wound healing is a crucial determinant of a patient's quality of life, and novel materials for skin wound repair, such as bioactive peptides, are continuously being studied and developed. One such bioactive peptide, AESIS-1, has been studied for its well-established anti-rheumatoid arthritis properties. In this study, we attempted to use the anti-RA material AESIS-1 as a therapeutic wound-healing agent based on disease-modifying antirheumatic drugs (DMARDs), which can help restore prompt wound healing. The efficacy of AESIS-1 in wound healing was assessed using a full-thickness excision model in diabetic mice; this is a well-established model for studying chronic wound repair. Initial observations revealed that mice treated with AESIS-1 exhibited significantly advanced wound repair compared with the control group. In vitro studies revealed that AESIS-1 increased the migration activity of human dermal fibroblasts (HDFs) without affecting proliferative activity. Moreover, increased HDF cell migration is mediated by upregulating chemokine receptor expression, such as that of CXC chemokine receptor 2 (CXCR2). The upregulation of CXCR2 through AESIS-1 treatment enhanced the chemotactic reactivity to CXCR2 ligands, including CXC motif ligand 8 (CXCL8). AESIS-1 directly activates the ERK and p38 mitogen-activated protein kinase (MAPK) signaling cascades, which regulate the migration and expression of CXCR2 in fibroblasts. Our results suggest that the AESIS-1 peptide is a strong wound-healing substance that increases the movement of fibroblasts and the expression of CXCR2 by turning on the ERK and p38 MAPK signaling cascades.

First-Intention Incisional Wound Healing in Dogs and Cats: A Controlled Trial of Dermapliq and Manuka Honey

This study aimed to compare incisional wound healing in cats and dogs after the topical application of Μanuka honey and a new medical device, Dermapliq. Comparisons were made between each treatment and control, between the two treatments, and between dogs and cats. Twelve cats and twelve dogs were included in this study, and the impact of the two substances was examined through cosmetic, clinical, ultrasonographical, and histological evaluation. The use of Dermapliq in first-intention wound healing achieved a significantly better cosmetic evaluation score and better total clinical score at days 20-41, compared to the control, in both dogs and cats. The ultrasonographically estimated wound area was smaller with Dermapliq compared to the control. Wounds treated with Dermapliq showed histologically less inflammation compared to the control. The use of Manuka honey did not show a significantly better cosmetic score compared to the control. Skin thickening was significantly higher after using Manuka honey compared to the control and so was the total clinical score. However, the median wound area, as was evaluated ultrasonographically, was significantly smaller when wounds were treated with Manuka honey, the difference being more apparent in dogs. Dermapliq was proven to be a better choice in achieving favorable wound healing than Manuka honey in dogs and cats in first-intention healing. In our study, cats had a statistically better cosmetic score and less skin thickening and scar width compared to dogs. Histologically, cats showed significantly less edema, higher inflammation and angiogenesis scores, and lower fibroblast and epidermis thickening scores when compared to dogs.

From Time to Timer in Wound Healing Through the Regeneration

Hard-to-heal wounds are an important public health issue worldwide, with a significant impact on the quality of life of patients. It is estimated that approximately 1-2% of the global population suffers from difficult wounds, which can be caused by a variety of factors such as trauma, infections, chronic diseases like diabetes or obesity, or poor health conditions. Hard-to-heal wounds are often characterized by a slow and complicated healing process, which can lead to serious complications such as infections, pressure ulcers, scar tissue formation, and even amputations. These complications can have a significant impact on the mobility, autonomy, and quality of life of patients, leading to an increase in healthcare and social costs associated with wound care. The preparation of the wound bed is a key concept in the management of hard-to-heal wounds, with the aim of promoting an optimal environment for healing. The TIME (Tissue, Infection/Inflammation, Moisture, Edge) model is a systematic approach used to assess and manage wounds in a targeted and personalized way. The concept of TIMER, expanding the TIME model, further focuses on regenerative processes, paying particular attention to promoting tissue regeneration and wound healing in a more effective and comprehensive way. The new element introduced in the TIMER model is "Regeneration", which highlights the importance of activating and supporting tissue regeneration processes to promote complete and lasting wound healing. Regenerative therapies can include a wide range of approaches, including cellular therapies, growth factors, bioactive biomaterials, stem cell therapies, and growth factor therapies. These therapies aim to promote the formation of new healthy tissues, reduce inflammation, improve vascularization, and stimulate cellular proliferation to accelerate wound closure and prevent complications. Thanks to continuous progress in research and development of regenerative therapies, more and more patients suffering from difficult wounds can benefit from innovative and promising solutions to promote faster and more effective healing, improve quality of life, and reduce the risk of long-term complications.

Electrospun Nanofiber Scaffolds Loaded with Metal-Based Nanoparticles for Wound Healing

Failures of wound healing have been a focus of research worldwide. With the continuous development of materials science, electrospun nanofiber scaffolds loaded with metal-based nanoparticles provide new ideas and methods for research into new tissue engineering materials due to their excellent antibacterial, anti-inflammatory, and wound healing abilities. In this review, the stages of extracellular matrix and wound healing, electrospun nanofiber scaffolds, metal-based nanoparticles, and metal-based nanoparticles supported by electrospun nanofiber scaffolds are reviewed, and their characteristics and applications are introduced. We discuss in detail the current research on wound healing of metal-based nanoparticles and electrospun nanofiber scaffolds loaded with metal-based nanoparticles, and we highlight the potential mechanisms and promising applications of these scaffolds for promoting wound healing.