Wound healing: biologic features and approaches to maximize healing trajectories

A mathematical model for wound healing in the reef-building coral Pocillopora damicornis

Coral reefs, among the most diverse ecosystems on Earth, currently face major threats from pollution, unsustainable fishing practices , and perturbations in environmental parameters brought on by climate change. Corals also sustain regular wounding from other sea life and human activity. Recent reef restoration practices have even involved intentional wounding by systematically breaking coral fragments and relocating them to revitalize damaged reefs, a practice known as microfragmentation. Despite its importance, very little research has explored the inner mechanisms of wound healing in corals. Some reef-building corals have been observed to initiate an immunological response to wounding similar to that observed in mammalian species. Utilizing prior models of wound healing in mammalian species as the mathematical basis, we formulated a mechanistic model of wound healing, including observations of the immune response and tissue repair in scleractinian corals for the species Pocillopora damicornis. The model consists of four differential equations which track changes in remaining wound debris, number of cells involved in inflammation, number of cells involved in proliferation, and amount of wound closure through re-epithelialization. The model is fit to experimental wound size data from linear and circular shaped wounds on a live coral fragment. Mathematical methods, including numerical simulations and local sensitivity analysis, were used to analyze the resulting model. The parameter space was also explored to investigate drivers of other possible wound outcomes. This model serves as a first step in generating mathematical models for wound healing in corals that will not only aid in the understanding of wound healing as a whole, but also help optimize reef restoration practices and predict recovery behavior after major wounding events.

Systemic Factors Affecting Healing in Dentistry

Healing process in the oral cavity is influenced by a range of systemic factors. More specifically, patient health status, medications, habits, and nutritional state play crucial roles in dental healing. Additionally, the body's immune response, inflammation, and overall well-being are key determinants in wound repair. Understanding these systemic factors is essential for dental professionals to optimize patient care, minimize complications, and achieve successful healing.

Inferring skin-brain-skin connections from infodemiology data using dynamic Bayesian networks

The relationship between skin diseases and mental illnesses has been extensively studied using cross-sectional epidemiological data. Typically, such data can only measure association (rather than causation) and include only a subset of the diseases we may be interested in. In this paper, we complement the evidence from such analyses by learning an overarching causal network model over twelve health conditions from the Google Search Trends Symptoms public data set. We learned the causal network model using a dynamic Bayesian network, which can represent both cyclic and acyclic causal relationships, is easy to interpret and accounts for the spatio-temporal trends in the data in a probabilistically rigorous way. The causal network confirms a large number of cyclic relationships between the selected health conditions and the interplay between skin and mental diseases. For acne, we observe a cyclic relationship with anxiety and attention deficit hyperactivity disorder (ADHD) and an indirect relationship with depression through sleep disorders. For dermatitis, we observe directed links to anxiety, depression and sleep disorders and a cyclic relationship with ADHD. We also observe a link between dermatitis and ADHD and a cyclic relationship between acne and ADHD. Furthermore, the network includes several direct connections between sleep disorders and other health conditions, highlighting the impact of the former on the overall health and well-being of the patient. The average R 2 for a condition given the values of all conditions in the previous week is 0.67: in particular, 0.42 for acne, 0.85 for asthma, 0.58 for ADHD, 0.87 for burn, 0.76 for erectile dysfunction, 0.88 for scars, 0.57 for alcohol disorders, 0.57 for anxiety, 0.53 for depression, 0.74 for dermatitis, 0.60 for sleep disorders and 0.66 for obesity. Mapping disease interplay, indirect relationships, and the key role of mediators, such as sleep disorders, will allow healthcare professionals to address disease management holistically and more effectively. Even if we consider all skin and mental diseases jointly, each disease subnetwork is unique, allowing for more targeted interventions.

Hydrogel-based immunoregulation of macrophages for tissue repair and regeneration

The rational design of hydrogel materials to modulate the immune microenvironment has emerged as a pivotal approach in expediting tissue repair and regeneration. Within the immune microenvironment, an array of immune cells exists, with macrophages gaining prominence in the field of tissue repair and regeneration due to their roles in cytokine regulation to promote regeneration, maintain tissue homeostasis, and facilitate repair. Macrophages can be categorized into two types: classically activated M1 (pro-inflammatory) and alternatively activated M2 (anti-inflammatory and pro-repair). By regulating the physical and chemical properties of hydrogels, the phenotypic transformation and cell behavior of macrophages can be effectively controlled, thereby promoting tissue regeneration and repair. A full understanding of the interaction between hydrogels and macrophages can provide new ideas and methods for future tissue engineering and clinical treatment. Therefore, this paper reviews the effects of hydrogel components, hardness, pore size, and surface morphology on cell behaviors such as macrophage proliferation, migration, and phenotypic polarization, and explores the application of hydrogels based on macrophage immune regulation in skin, bone, cartilage, and nerve tissue repair. Finally, the challenges and future prospects of macrophage-based immunomodulatory hydrogels are discussed.

Utilization of a Decellularized Skin Scaffold for Repair of a Cleft Palate in a Dog: A Case Report

Cleft palates are oral deformities that mostly affect puppies. They are frequently extensive and characterized by bone and palatal mucosa malformation. This deformity is a serious condition that may result in the death of the dog, therefore surgical treatment is recommended. Tissue bioengineering has emerged as a valuable option to treat cleft palates by applying acellular biological scaffolds as grafts. This case report proposed a new approach for surgical correction of canine cleft palate through a grafting technique using a decellularized scaffold. A decellularized portion of skin was implanted to correct a large cleft palate in a 3-month-old female Pug dog. The skin fragment was obtained from a dog cadaver and a decellularization protocol was performed. Under general anesthesia, a bilateral mucoperiosteal separation of the entire length of cleft margins was performed, and the scaffold was then positioned between the tissue and the bone palate. The interaction of the grafted scaffold with the oral mucosa and palatine layers resulted in total cleft closure, without postsurgical rejection or infection, indicating the applicability of this technique in dog's cleft palate correction. This is the first reported case demonstrating this new technique, which resulted in full cleft closure and healing.

Assessing the efficacy of curcumin-loaded alginate hydrogel on skin wound healing: A gene expression analysis

Skin tissue engineering has gained significant attention as a promising alternative to traditional treatments for skin injuries. In this study, we developed 3D hydrogel-based scaffolds, Alginate, incorporating different concentrations of Curcumin and evaluated their properties, including morphology, swelling behavior, weight loss, as well as hemo- and cytocompatibility. Furthermore, we investigated the therapeutic potential of Alginate hydrogel containing different amounts of Curcumin using an in vitro wound healing model. The prepared hydrogels exhibited remarkable characteristics, SEM showed that the pore size of hydrogels was 134.64 μm with interconnected pores, making it conducive for cellular infiltration and nutrient exchange. Moreover, hydrogels demonstrated excellent biodegradability, losing 63.5% of its weight over 14 days. In addition, the prepared hydrogels had a stable release of curcumin for 3 days. The results also show the hemocompatibility of prepared hydrogels and a low amount of blood clotting. To assess the efficacy of the developed hydrogels, 3T3 fibroblast growth was examined during various incubation times. The results indicated that the inclusion of Curcumin at a concentration of 0.1 mg/mL positively influenced cellular behavior. The animal study showed that Alginate hydrogel containing 0.1 mg/mL curcumin had high wound closure(more than 80%) after 14 days. In addition, it showed up-regulation of essential wound healing genes, including TGFβ1 and VEGF, promoting tissue repair and angiogenesis. Furthermore, the treated group exhibited down-regulation of MMP9 gene expression, indicating a reduction in matrix degradation and inflammation. The observed cellular responses and gene expression changes substantiate the therapeutic efficacy of prepared hydrogels. Consequently, our study showed the healing effect of alginate-based hydrogel containing Curcumin on skin injuries.

Electrospinning of biomimetic materials with fibrinogen for effective early-stage wound healing

Electrospun biomimetic materials based on polyester of natural origin poly-3-hudroxybutyrate (PHB) modified with hemin (Hmi) and fibrinogen (Fbg) represent a great interest and are potentially applicable in various fields. Here, we describe formulation of the new fibrous PHB-Fbg and PHB-Hmi-Fbg materials with complex structure for biomedical application. The average diameter of the fibers was 3.5 μm and 1.8 μm respectively. Hmi presence increased porosity from 80 % to 94 %, significantly reduced the number of defects, ensured the formation of a larger number of open pores, and improved mechanical properties. Hmi presence significantly improved the molding properties of the material. Hmi facilitated effective Fbg adsorption on the of the PHB wound-healing material, ensuring uniform localization of the protein on the surface of the fibers. Next, we evaluated cytocompatibility, cell behavior, and open wound healing in mice. The results demonstrated that PHB-Fbg and PHB-Hmi-Fbg electrospun materials had pronounced properties and may be promising for early-stage wound healing - the PHB-Hmi-Fbg sample accelerated wound closure by 35 % on the 3rd day, and PHB-Hmi showed 45 % more effective wound closure on the 15th day.

Making Sense of Electrical Stimulation: A Meta-analysis for Wound Healing

Electrical stimulation as a mode of external enhancement factor in wound healing has been explored widely. It has proven to have multidimensional effects in wound healing including antibacterial, galvanotaxis, growth factor secretion, proliferation, transdifferentiation, angiogenesis, etc. Despite such vast exploration, this modality has not yet been established as an accepted method for treatment. This article reviews and analyzes the approaches of using electrical stimulation to modulate wound healing and discusses the incoherence in approaches towards reporting the effect of stimulation on the healing process. The analysis starts by discussing various processes adapted in in vitro, in vivo, and clinical practices. Later it is focused on in vitro approaches directed to various stages of wound healing. Based on the analysis, a protocol is put forward for reporting in vitro works in such a way that the outcomes of the experiment are replicable and scalable in other setups. This work proposes a ground of unification for all the in vitro approaches in a more sensible manner, which can be further explored for translating in vitro approaches to complex tissue stimulation to establish electrical stimulation as a controlled clinical method for modulating wound healing.

Topical metformin accelerates wound healing by promoting collagen synthesis and inhibiting apoptosis in a diabetic wound model

The wound healing process, which is a pathophysiological process that includes various phases, is interrupted in diabetes due to hyperglycemia, and since deterioration occurs in these phases, a normal healing process is not observed. The aim of the current study is to investigate the proliferative and antiapoptotic effects of metformin on wound healing after topical application on diabetic and non-diabetic wounds. For this purpose, we applied metformin topically on the full-thickness excisional wound model we created in diabetic and nondiabetic groups. We investigated the effects of metformin on the apoptotic index by the Terminal deoxynucleotidyl transferase mediated dUTP Nick-End Labeling method and on collagen-I, collagen-III, p53, and c-jun expression levels by quantitative reverse transcription polymerase chain reaction technique in wound biopsy tissues. Our results showed that c-jun and p53 mRNA levels and apoptotic index increased with the effect of diabetes, while collagen synthesis was disrupted. As a result of the study, we showed that metformin increases cellular proliferation and has anti-apoptotic effects by increasing collagen-I/III expression and decreasing p53/c-jun level, especially in diabetic wounds and also in normal wounds. In conclusion, the topical effect of metformin on diabetic wounds reversed the adverse effects caused by diabetes, increasing the wound healing rate and improving the wound repair process.

Current Trends on Innovative Technologies in Topical Wound Care for Advanced Healing and Management

OBJECTIVES

To investigate critically traditional and modern techniques for cutaneous wound healing and to provide comprehensive information on these novel techniques to encounter the challenges with the existing wound healing methods.

SIGNIFICANCE

The financial burden and mortality associated with wounds is increasing, so managing wounds is essential. Traditional wound treatments include surgical and non-surgical methods, while modern techniques are advancing rapidly. This review examines the various traditional and modern techniques used for cutaneous wound healing.

KEY FINDINGS

Traditional wound treatments include surgical techniques such as debridement, skin flaps, and grafts. Non-surgical treatments include skin replacements, topical formulations, scaffold-based skin grafts, and hydrogel-based skin dressings. More modern techniques include using nanoparticles, growth factors, and bioactive substances in wound dressings. Bioengineered skin substitutes using biomaterials, cells, and growth factors are also being developed. Other techniques include stem cell therapy, growth factor/cytokine therapy, vacuum-assisted wound closure, and 3D-printed/bio-printed wound dressings.

CONCLUSION

Traditional wound treatments have been replaced by modern techniques such as stem cell therapy, growth factor/cytokine therapy, vacuum-assisted wound closure, and bioengineered skin substitutes. However, most of these strategies lack effectiveness and thorough evaluation. Therefore, further research is required to develop new techniques for cutaneous wound healing that are effective, cost-efficient, and appealing to patients.

The recent development of carbon-based nanoparticles as a novel approach to skin tissue care and management - A review

Since the skin is the first barrier of the body's defense against pathogens, delays in the healing process are affected by infections. Therefore, applying advanced substitute assistance improves the patient's quality of life. Carbon-based nanomaterials show better capabilities than conventional methods for managing skin wound infections. Due to their physicochemical properties such as small size, large surface area, great surface-to-volume ratio, and excellent ability to communicate with the cells and tissue, carbon-based nanoparticles have been considered in regenerative medicine. moreover, the carbon nano family offers attractive potential in wound healing via the improvement of angiogenesis and antibacterial compared to traditional approaches become one of the particular research interests in the field of skin tissue engineering. This review emphasizes the wound-healing process and the role of carbon-based nanoparticles in wound care management interaction with tissue engineering technology.

Incisional Hernia: A Surgical Complication or Medical Disease?

Incisional hernia (IH) is a frequent complication following abdominal surgery. The development of IH could be more sophisticated than a simple anatomical failure of the abdominal wall. Reported IH incidence varies among studies. This review presented an overview of definitions, molecular basis, risk factors, incidence, clinical presentation, surgical techniques, postoperative care, cost, risk prediction tools, and proposed preventative measures. A literature search of PubMed was conducted to include high-quality studies on IH. The incidence of IH depends on the primary surgical pathology, incision site and extent, associated medical comorbidities, and risk factors. The review highlighted inherent and modifiable risk factors. The disorganisation of the extracellular matrix, defective fibroblast functions, and ratio variations of different collagen types are implicated in molecular mechanisms. Elective repair of IH alleviates symptoms, prevents complications, and improves the quality of life (QOL). Recent studies introduced risk prediction tools to implement preventative measures, including suture line reinforcement or prophylactic mesh application in high-risk groups. Elective repair improves QOL and prevents sinister outcomes associated with emergency IH repair. The watchful wait strategy should be reviewed, and options should be discussed thoroughly during patients' counselling. Risk stratification tools for predicting IH would help adopt prophylactic measures.

Pathogenesis of non-infection related inflammatory root resorption in permanent teeth: A narrative review

BACKGROUND

The mechanism of action of root resorption in a permanent tooth can be classified as infection-related (e.g., microbial infection) or non-infection-related (e.g., sterile damage). Infection induced root resorption occurs due to bacterial invasion. Non-infection-related root resorption stimulates the immune system through a different mechanism.

OBJECTIVES

The aim of this narrative review is to describe the pathophysiologic process of non-infection-related inflammatory processes involved in root resorption of permanent teeth.

METHODS

A literature search on root resorption was conducted using Scopus (PubMed and Medline) and Google Scholar databases to highlight the pathophysiology of bone and root resorption in non-infection-related situations. The search included key words covering the relevant category. It included in vitro and in vivo studies, systematic reviews, case series, reviews, and textbooks in English. Conference proceedings, lectures and letters to the editor were excluded.

RESULTS

Three types of root resorption are related to the non-infection mechanism of action, which includes surface resorption due to either trauma or excessive orthodontic forces, external replacement resorption and external cervical resorption. The triggers are usually damage associated molecular patterns and hypoxia conditions. During this phase macrophages and clastic cells act to eliminate the damaged tissue and bone, eventually enabling root resorption and bone repair as part of wound healing.

DISCUSSION

The resorption of the root occurs during the inflammatory phase of wound healing. In this phase, damaged tissues are recognized by macrophages and neutrophiles that secrete interlaukines such as TNF-α, IL-1, IL-6, IL-8. Together with the hypoxia condition that accelarates the secretion of growth factors, the repair of the damaged perioduntiom, including damaged bone, is initiated. If the precementum and cementoblast are injured, root resorption can occur.

CONCLUSIONS

Wound healing exhibits different patterns of action that involves immune stimulation in a bio-physiological activity, that occurs in the proper sequence, with overlapping phases. Two pathologic conditions, DAMPs and hypoxia, can activate the immune cells including clastic cells, eliminating damaged tissue and bone. Under certain conditions, root resorption occurs as a side effect.

Development and optimization of film forming non-pressurized liquid bandage for wound healing by Box-Behnken statistical design

The goal of the current investigation was to develop a non-pressurized liquid bandage to promote the healing of wounds by using silver sulfadiazine. A three-factor three level box-behnken statistical design was employed to optimize the drug-loaded liquid bandage. Film-forming liquid bandage was developed by using ethyl-cellulose, dibutyl sebacate, and glycerol. For optimization, ethyl cellulose, dibutyl sebacate, and isopropyl myristate were taken as independent variables while tensile strength, water vapor absorption value, and drying time were taken as dependent variables. The film-forming liquid bandage was evaluated for various parameters like tensile strength, water vapor absorption value, drying time, viscosity, pH, in-vitro drug release studies, in-vivo wound healing studies, and stability studies. The optimized formulation was found with the tensile strength of 68.24 ± 0.24 MPa, water vapor absorption value of 2.00 ± 0.25 %, drying time of 1.75 ± 0.14 min, viscosity of 60 ± 0.5 cPs, pH of 6.0 ± 0.5 and good physicochemical properties with satisfactory film-forming ability. The in-vitro study shows that the release of test formulations was better than the marketed formulation. After 6 h of study, the liquid bandage and marketed formulation showed 41.02 % and 29.32 % of drug release respectively. Significant results were obtained for the in-vivo wound healing studies. Upon comparison with the control group (2.61 mm) and marketed formulation (1.44 mm), rats treated with the optimized formulation exhibited a noticeable improvement in wound contraction (0.8 mm). The liquid bandage after three months of stability testing was found to be stable with optimum. The film-forming liquid bandage was found to be an effective alternative to conventional topical preparations as it develops a thin polymeric layer on the wound and the skin around it and improves comfort for the patient by protecting the wound from external factors and physical harm.

Antibacterial Effect and Therapy of Chronic Skin Defects Using the Composite Bioscaffold Polycaprolactone/GelitaSpon/Povidone-Iodine in Domestic Dogs

Chronic wounds and the failure of conventional treatment are relatively common in veterinary medicine. Recently, there has been a growing interest in alternative therapeutic approaches and the utilization of biodegradable materials. Their potential application in wound therapy may offer a novel and more suitable option compared to conventional treatment methods. Biodegradable materials can be classified into two main categories: natural, synthetic, and a combination of both, which have the potential to have synergistically enhanced properties. In this study, four domestic dogs with clinical symptoms of chronic wounds were enrolled. These wounds underwent treatment utilizing a novel biodegradable composite material composed of gelatin sponge combined with two electrospun layers of polycaprolactone (PCL) along with polyvinylpyrrolidone (PVP) fibers containing povidone-iodine complex (PVP-I). The initial phase of the study was dedicated to evaluating the antibacterial properties of iodine against Staphylococcus aureus and Escherichia coli. On average, wound healing in domestic dogs took 22 days from the initial treatment, and iodine concentrations demonstrated a significant antibacterial effect against Escherichia coli and Staphylococcus aureus. Based on the favorable outcomes observed in wound management, we believe that the utilization of a blend of natural and synthetic biodegradable materials holds promise as an effective wound therapy option.

The functions and clinical application potential of exosomes derived from mesenchymal stem cells on wound repair: a review of recent research advances

Wound repair is a complex problem for both clinical practitioners and scientific investigators. Conventional approaches to wound repair have been associated with several limitations, including prolonged treatment duration, high treatment expenses, and significant economic and psychological strain on patients. Consequently, there is a pressing demand for more efficacious and secure treatment modalities to enhance the existing treatment landscapes. In the field of wound repair, cell-free therapy, particularly the use of mesenchymal stem cell-derived exosomes (MSC-Exos), has made notable advancements in recent years. Exosomes, which are small lipid bilayer vesicles discharged by MSCs, harbor bioactive constituents such as proteins, lipids, microRNA (miRNA), and messenger RNA (mRNA). These constituents facilitate material transfer and information exchange between the cells, thereby regulating their biological functions. This article presents a comprehensive survey of the function and mechanisms of MSC-Exos in the context of wound healing, emphasizing their beneficial impact on each phase of the process, including the regulation of the immune response, inhibition of inflammation, promotion of angiogenesis, advancement of cell proliferation and migration, and reduction of scar formation.

Recent Advances in Functional Wound Dressings

Significance: Nowadays, the wound dressing is no longer limited to its primary wound protection ability. Hydrogel, sponge-like material, three dimensional-printed mesh, and nanofiber-based dressings with incorporation of functional components, such as nanomaterials, growth factors, enzymes, antimicrobial agents, and electronics, are able to not only prevent/treat infection but also accelerate the wound healing and monitor the wound-healing status. Recent Advances: The advances in nanotechnologies and materials science have paved the way to incorporate various functional components into the dressings, which can facilitate wound healing and monitor different biological parameters in the wound area. In this review, we mainly focus on the discussion of recently developed functional wound dressings. Critical Issues: Understanding the structure and composition of wound dressings is important to correlate their functions with the outcome of wound management. Future Directions: "All-in-one" dressings that integrate multiple functions (e.g., monitoring, antimicrobial, pain relief, immune modulation, and regeneration) could be effective for wound repair and regeneration.

Lignin-Cobalt Nano-Enabled Poly(pseudo)rotaxane Supramolecular Hydrogel for Treating Chronic Wounds

Chronic wounds (CWs) are a growing issue for the health care system. Their treatment requires a synergic approach to reduce both inflammation and the bacterial burden. In this work, a promising system for treating CWs was developed, comprising cobalt-lignin nanoparticles (NPs) embedded in a supramolecular (SM) hydrogel. First, NPs were obtained through cobalt reduction with phenolated lignin, and their antibacterial properties were tested against both Gram-negative and Gram-positive strains. The anti-inflammatory capacity of the NPs was proven through their ability to inhibit myeloperoxidase (MPO) and matrix metalloproteases (MMPs), which are enzymes involved in the inflammatory process and wound chronicity. Then, the NPs were loaded in an SM hydrogel based on a blend of α-cyclodextrin and custom-made poly(ether urethane)s. The nano-enabled hydrogel showed injectability, self-healing properties, and linear release of the loaded cargo. Moreover, the SM hydrogel's characteristics were optimized to absorb proteins when in contact with liquid, suggesting its capacity to uptake harmful enzymes from the wound exudate. These results render the developed multifunctional SM material an interesting candidate for the management of CWs.

Investigation of UV-treated mesenchymal stem cells in an in vitro wound model

This study examines the effects of ultraviolet-induced adipose tissue-derived mesenchymal stem cells and their supernatants on wound healing regarding cell viability, percentage of wound healing, released cytokine, and growth factors. It has been reported in previous studies that mesenchymal stem cells are resistant to ultraviolet light and have a protective effect on skin cells against ultraviolet-induced damage. At the same time, there are many studies in the literature about the positive effects of cytokines and growth factors secreted by mesenchymal stem cells. Based on this information, the effects of ultraviolet-induced adipose-derived stem cells and supernatants containing their secreted cytokines and growth factors on an in vitro two-dimensional wound model created with two different cell lines were investigated in this study. It was determined from the results that the highest cell viability and the least apoptotic staining were 100 mJ in mesenchymal stem cells (**p < 0.01). Furthermore, analysis of cytokines and growth factors collected from supernatants also supported 100 mJ as the optimal ultraviolet dose. It was observed that cells treated with ultraviolet and their supernatants significantly increased cell viability and wound-healing rate over time compared to other groups. In conclusion, with this study, it has been shown that adipose-derived stem cells exposed to ultraviolet light can have an important use in wound healing, both with their potential and with the more cytokines and growth factors they secrete. However, further analysis and animal experiments should be performed before clinical use.

Step-by-Step Regeneration of Tentacles after Injury in Anemonia viridis-Morphological and Structural Cell Analyses

Benthic marine invertebrates, such as corals, are often subjected to injury caused by several sources. Here, the differences and characteristics in injured and health tissues in terms of cellular components are shown through a histological investigation of the soft coral Anemonia viridis at 0 h, 6 h, 24 h, and 7 days after injury caused by tentacle amputation. In addition, a new tool was used for the first time in invertebrates, positron emission tomography, in order to investigate the events that occur during regeneration within a longer time period (0 h, 24 h, and 14 days after the tentacles were cut). Higher integrated density values were measured through a densitometric analysis in sections stained with Fontana-Masson at 24 h after the tentacles were cut. This suggests an increase in melanin-like containing cells and a subsequent increase in fibroblast-like cells differentiated by amoebocytes that converge to the lesion site in the early stages of inflammation and regeneration. This work provides, for the first time, an elucidation of the events that occur during wound-healing and regeneration in basal metazoan, focusing on the characterisation of immune cells and their role. Our results indicate that Mediterranean anthozoan proves to be a valuable model for studying regeneration. Many events highlighted in this research occur in different phyla, suggesting that they are highly conserved.

PRP of T2DM Patient Immobilized on PCL Nanofibers Stimulate Endothelial Cells Proliferation

Diabetic foot ulcers (DFU) are a common complication of Type 2 Diabetes Mellitus (T2DM). Development of bioactive wound healing covers is an important task in medicine. The use of autologous platelet-rich plasma (PRP) consisting of growth factors, cytokines and components of extracellular matrix is a perspective approach for DFU treatment, but we previously found that some T2DM PRP samples have a toxic effect on mesenchymal stem cells (MSCs) in vitro. Here, we covalently immobilized T2DM PRP proteins on polycaprolactone (PCL) nanofibers, and the growth of endothelial cells on the PCL-COOH-PRP was investigated. Additionally, the level of NO reflecting the cytotoxic effects of PRP, angiogenin, and VEGF levels were measured in T2DM PRP samples. The results showed that the application of PCL-COOH-PRP nanofibers allows to remove the cytotoxicity of T2DM PRP and to improve endothelial cell adhesion and proliferative activity. We showed that the origin of T2DM PRP (the level of PRP toxicity or presence/absence of DFU) does not influence the efficiency of cell growth on PCL-COOH-PRP, and on the level of angiogenin, vascular epidermal growth factor (VEGF) in PRP itself.

Design, optimization and characterization of a novel antibacterial chitosan-based hydrogel dressing for promoting blood coagulation and full-thickness wound healing: A biochemical and biophysical study

The use of hydrogel dressings has become increasingly popular as a scaffold for skin tissue engineering. Herein, we have developed an innovative wound dressing using chitosan, fibrinogen, nisin, and EDTA as an effective antibacterial scaffold for wound treatment. The structural and functional characteristics of the hydrogel, including morphology, mechanical strength, drug encapsulation and release, swelling behaviors, blood coagulation, cytotoxicity, and antibacterial activity, were studied. Spectroscopic studies indicated that the attachment of chitosan to fibrinogen is associated with minimal change in its secondary structure; subsequently, at higher temperatures, it is expected to preserve fibrinogen's conformational stability. Mechanical and blood coagulation analyses indicated that the incorporation of fibrinogen into the hydrogel resulted in accelerated clotting and enhanced mechanical properties. Our cell studies showed biocompatibility and non-toxicity of the hydrogel along with the promotion of cell migration. In addition, the prepared hydrogel indicated an antibacterial behavior against both Gram-positive and Gram-negative bacteria. Interestingly, the in vivo data revealed enhanced tissue regeneration and recovery within 17 days in the studied animals. Taken together, the results obtained from in vitro and histological assessments indicate that this innovatively designed hydrogel shows good potential as a candidate for wound healing.

The Effect of Fetal Bovine Acellular Dermal Matrix Seeded with Wharton's Jelly Mesenchymal Stem Cells for Healing Full-Thickness Skin Wounds

The treatment of full-thickness skin wounds is a problem in the clinical setting, as they do not heal spontaneously. Extensive pain at the donor site and a lack of skin grafts limit autogenic and allogeneic skin graft availability. We evaluated fetal bovine acellular dermal matrix (FADM) in combination with human Wharton's jelly mesenchymal stem cells (hWJ-MSCs) to heal full-thickness skin wounds. FADM was prepared from a 6-month-old trauma-aborted fetus. WJ-MSCs were derived from a human umbilical cord and seeded on the FADM. Rat models of full-thickness wounds were created and divided into three groups: control (no treatment), FADM, and FADM-WJMSCs groups. Wound treatment was evaluated microscopically and histologically on days 7, 14, and 21 post-surgery. The prepared FADM was porous and decellularized with a normal range of residual DNA. WJ-MSCs were seeded and proliferated on FADM effectively. The highest wound closure rate was observed in the FADM-WJMSC group on days 7 and 14 post-surgery. Furthermore, this group had fewer inflammatory cells than other groups. Finally, in this study, we observed that, without using the differential cell culture media of fibroblasts, the xenogeneic hWJSCs in combination with FADM could promote an increased rate of full-thickness skin wound closure with less inflammation.

Dressing Materials: A Comprehensive Review

Injury to the skin provides a difficult challenge, as wound healing is a complex and dynamic process. Wound healing process recruits three different phases: inflammation, proliferation, and maturation. The sequence of events involved in wound healing can be affected by numerous disease processes, resulting in chronic, non-healing wounds that give significant discomfort and distress to the patients while draining the medical fraternity of enormous resources. Wound tissue never reaches its pre-injured strength and multiple aberrant healing states can result in chronic non-healing wounds. There is a growing concern about the usage of correct materials for wound dressings. The development of new and effective treatments in wound care still remains an area of intense research. There are a number of wound dressings available in the market. The objective of the article is to enhance knowledge about characteristics of an ideal wound dressing and guide in finding the correct dressing material. It also provides a detailed classification of traditional and modern wound dressings.

Recent Tissue Engineering Approaches to Mimicking the Extracellular Matrix Structure for Skin Regeneration

Inducing tissue regeneration in many skin defects, such as large traumatic wounds, burns, other physicochemical wounds, bedsores, and chronic diabetic ulcers, has become an important clinical issue in recent years. Cultured cell sheets and scaffolds containing growth factors are already in use but have yet to restore normal skin tissue structure and function. Many tissue engineering materials that focus on the regeneration process of living tissues have been developed for the more versatile and rapid initiation of treatment. Since the discovery that cells recognize the chemical-physical properties of their surrounding environment, there has been a great deal of work on mimicking the composition of the extracellular matrix (ECM) and its three-dimensional network structure. Approaches have used ECM constituent proteins as well as morphological processing methods, such as fiber sheets, sponges, and meshes. This review summarizes material design strategies in tissue engineering fields, ranging from the morphology of existing dressings and ECM structures to cellular-level microstructure mimicry, and explores directions for future approaches to precision skin tissue regeneration.

Effect of Chitosan-Diosgenin Combination on Wound Healing

The difficult-to-heal wounds continue to be a problem for modern medicine. Chitosan and diosgenin possess anti-inflammatory and antioxidant effects making them relevant substances for wound treatment. That is why this work aimed to study the effect of the combined application of chitosan and diosgenin on a mouse skin wound model. For the purpose, wounds (6 mm diameter) were made on mice's backs and were treated for 9 days with one of the following: 50% ethanol (control), polyethylene glycol (PEG) in 50% ethanol, chitosan and PEG in 50% ethanol (Chs), diosgenin and PEG in 50% ethanol (Dg) and chitosan, diosgenin and PEG in 50% ethanol (ChsDg). Before the first treatment and on the 3rd, 6th and 9th days, the wounds were photographed and their area was determined. On the 9th day, animals were euthanized and wounds' tissues were excised for histological analysis. In addition, the lipid peroxidation (LPO), protein oxidation (POx) and total glutathione (tGSH) levels were measured. The results showed that ChsDg had the most pronounced overall effect on wound area reduction, followed by Chs and PEG. Moreover, the application of ChsDg maintained high levels of tGSH in wound tissues, compared to other substances. It was shown that all tested substances, except ethanol, reduced POx comparable to intact skin levels. Therefore, the combined application of chitosan and diosgenin is a very promising and effective medication for wound healing.

Effect of femtosecond laser interaction with human fibroblasts: a preliminary study

In in vitro methods and cell culture models, femtosecond (fs) laser interaction has been employed to assess its effect on the proliferation and morphology of human skin fibroblasts. We cultured a primary human skin fibroblast cell line on a glass plate, passages 17-23. The cells were irradiated with a 90-fs laser at a wavelength of 800 nm and a repetition rate of 82 MHz. The target received an average power of 320 mW for 5, 20, and 100 s, corresponding to the radiation exposures of 22.6, 90.6, and 452.9 J/cm2, respectively. Using a laser scanning microscopy technique, the photon densities were measured to be 6.4 × 1018, 2.6 × 1019, and 1.3 × 1020 photons/cm2 in a spot area of 0.07 cm2; the recorded spectra were obtained from the laser interaction after 0.00, 1.00, 25.00, and 45.00 h. The cell count and morphological changes showed that the cultured cells were affected by laser irradiation under photon stress; some fibroblasts were killed, while others were injured and survived. We discovered evidence of the formation of several coenzyme compounds, such as flavin (500-600 nm), lipopigments (600-750 nm), and porphyrin (500-700 nm). This study is motivated by the future development of a novel, ultra-short fs laser system and the need to develop a basic in vitro understanding of photon-human cell interaction. The cell proliferation indicated that cells are partly killed or wounded. The exposure of fibroblasts to fs laser fluence up to 450 J/cm2 accelerates cell growth of the viable residual cell.

Recent Advances in Nano-Drug Delivery Systems for the Treatment of Diabetic Wound Healing

Diabetes mellitus (DM) induced wound healing impairment remains a serious health problem and burden on the clinical obligation for high amputation rates. Based on the features of wound microenvironment, biomaterials loading specific drugs can benefit diabetic wound treatment. Drug delivery systems (DDSs) can carry diverse functional substances to the wound site. Nano-drug delivery systems (NDDSs), benefiting from their features related to nano size, overcome limitations of conventional DDSs application and are considered as a developing process in the wound treatment field. Recently, a number of finely designed nanocarriers efficiently loading various substances (bioactive and non-bioactive factors) have emerged to circumvent constraints faced by traditional DDSs. This review describes various recent advances of nano-drug delivery systems involved in mitigating diabetes mellitus-based non-healing wounds.

The Effects of Chitosan on the Healing Process of Oral Mucosa: An Observational Cohort Feasibility Split-Mouth Study

The healing process is a dynamic process accompanied by some classical symptoms of inflammation such as redness, swelling, pain, and loss of function. Chitosan is a natural polymer with properties that contribute to tissue healing, with properties that could be applied in periodontal therapy, such as the wound healing of oral mucosa. This experimental split-mouth study aims to assess the possibilities of chitosan influencing the healing process of oral mucosa in eight patients, where the studied group was subjected to two oral surgeries: one with chitosan hydrogel into the socket and other without the biomaterial. A semi-quantitative analysis of the data was performed. Some classic signs of inflammation in a short period of time were observed where chitosan acted, compared to the control. An absence of bleeding was observed in the chitosan cases. According to the literature, chitosan recruits and activates neutrophils and macrophages and stimulates angiogenesis. Hemostatic and antimicrobial activity of chitosan also play an important role in wound healing. Chitosan seems to improve the postoperative quality of patients, allowing rapid wound healing with less complications.

Comparative Evaluation of Human Pulp Tissue Dissolution by 500-ppm and 200-ppm Hypochlorous Acid and 5.25% Sodium Hypochlorite: An In Vitro Study

AIM

The aim of this study was to assess, in vitro, the human pulp dissolution capacity of 500 ppm and 200 ppm of hypochlorous acid in comparison with 5.2% sodium hypochlorite (NaOCl).

MATERIALS AND METHODS

Forty pulp tissue samples were standardized to a weight of 9 mg and divided into four groups according to the irrigating solution used: 5.25% NaOCl, 500 ppm hypochlorous acid, 200 ppm hypochlorous acid, and distilled water. Eppendorf tubes carrying 2 mL of the irrigants were taken and the pulp tissue samples were placed in the tubes for the specified time interval: Subgroup A: 30 minutes and subgroup B: 60 minutes. After the designated time interval, the solution from each sample tube was filtered using Whatman filter paper and left for drying overnight. The residual weight was calculated by filtration method. The mean dissolution time for each experimental group at the different time intervals was statistically analyzed.

RESULTS

Mean tissue dissolution increases with an increase in the time period. Approximately 5.25% NaOCl was most effective at both time intervals followed by 500-ppm hypochlorous acid at 60 minutes. Least amount of tissue dissolution was shown by 200-ppm of hypochlorous acid at 30 minutes. Distilled water did not show the ability to dissolve human pulp tissue.

CONCLUSION

Within the limitations of the study, 5.25% NaOCl dissolved the pulp tissue most efficiently at both time intervals and both concentrations. Human pulp tissue dissolution by hypochlorous acid was found to gradually increase with time and with an increase in its concentration.

CLINICAL SIGNIFICANCE

With the basic information that hypochlorous acid does have the capacity to dissolve human pulp tissue, further research can be undertaken to assess methods to increase its efficiency. Sooner than later, hypochlorous acid may be able to completely replace the toxic NaOCl in clinical practice, as the irrigant of choice during root canal therapy.

Bacterial Cellulose-Based Materials as Dressings for Wound Healing

Bacterial cellulose (BC) is produced by several microorganisms as extracellular structures and can be modified by various physicochemical and biological strategies to produce different cellulosic formats. The main advantages of BC for biomedical applications can be summarized thus: easy moldability, purification, and scalability; high biocompatibility; and straightforward tailoring. The presence of a high amount of free hydroxyl residues, linked with water and nanoporous morphology, makes BC polymer an ideal candidate for wound healing. In this frame, acute and chronic wounds, associated with prevalent pathologies, were addressed to find adequate therapeutic strategies. Hence, the main characteristics of different BC structures-such as membranes and films, fibrous and spheroidal, nanocrystals and nanofibers, and different BC blends, as well as recent advances in BC composites with alginate, collagen, chitosan, silk sericin, and some miscellaneous blends-are reported in detail. Moreover, the development of novel antimicrobial BC and drug delivery systems are discussed.

Exosomes derived from mesenchymal stem cells: A promising cell-free therapeutic tool for cutaneous wound healing

Skin wound healing is a multifaceted process involving a cascade of molecular and cellular procedures that occur in four different phases: (a) hemostasis, (b) inflammation, (c) proliferation, and (d) tissue remodeling. Prolonged wound healing in skin is still a major challenge in treatment of wounds. Mesenchymal stem cells (MSCs) accelerate cutaneous wound healing through their paracrine activity. Exosomes are one of the key secretory products of MSCs, mimicking the effects of parental MSCs in skin wound healing process. Exosomes are small membrane vesicles (30-150 nm in diameter) that originate from endosomal pathways and transport numerous biomolecules, including DNAs, messenger RNAs, microRNAs, lipids, and proteins. They can be taken up by target cells and release their contents to modulate the activity of recipient cells. Exosomes derived from mesenchymal stem cells (MSC-Exo) reduce inflammation, promote proliferation, inhibit apoptosis, and enhance angiogenesis in skin wound healing process. Therefore, exosomes are emerging as novel cell-cell communication mediators and have opened a novel viewpoint for developing cell-free therapies. This review aims to demonstrate the roles of exosomes in each step of skin wound healing through a comprehensive literature search.

Delivery of a peptide/microRNA blend via electrospun antimicrobial nanofibres for wound repair

Downregulation of microRNA-31 (miR-31) and microRNA-132 (miR-132) has been associated with delayed wound healing. Therefore, it was hypothesised that intracellular delivery of miR-31 and miR-132, both as individual and blend formulations, could promote tissue repair. The use of a blend could minimise potential toxicity and achieve synergistic effects, thus maximising the therapeutic effect. miR-31 and miR-132 were condensed with a 30-mer positively charged amphipathic peptide, RALA, to form nanocomplexes with an average size <200 nm and zeta-potential ≥10 designed to facilitate cellular internalisation. This enabled a fold increase in miR-31 and miR-132 expression of ≥100,000 in a murine fibroblast cell line (NCTC-929) and a skin human keratinocyte cell line (HaCaT), with intracellular delivery >70% for individual and blend formulations. Moreover, incubation with the nanocomplexes increased the migration of HaCaT cells ≥25% at 4 and 8 h post-incubation, as well as downregulation of EMP-1 and RASA1 and HB-EGF and RASA1, target genes for miR-31 and miR-132, respectively. Electrospinning was then employed to produce an alginate/polyvinyl alcohol/ciprofloxacin nanofibrous wound patch to facilitate the controlled delivery of the nanocomplexes. Nanofibres were crosslinked with glutaraldehyde to improve stability in aqueous solvents, and they were proven to be biocompatible with antimicrobial activity without cellular attachment to avoid injury upon removal. RALA/miR nanoparticles were incorporated to the nanofibrous wound dressing and in vivo wound healing studies using C57BL/6J mice demonstrated a >60% acceleration in the wound closure rate at Day 7 post-wounding, a ≥1.5 increase in epidermal thickness, and a ≥2 increase in blood vessel count with respect to commercial and untreated controls. Taken together, this data proves that delivery of RALA/miR-31 and RALA/miR-132 from an alginate/polyvinyl alcohol/ciprofloxacin nanofibrous wound dressing constitutes an advanced therapy for wound healing, by accelerating wound closure and improving healed tissue quality. STATEMENT OF SIGNIFICANCE: In this study, we report for the first time the use of the RALA peptide to deliver two miRNA 31 & 132 simultaneously from an electrospun patch. Both miRs have been shown to be downregulated in wounds and this study endeavoured to deliver a blend of the miRs from a nanofibre patch. Electrospinning was used to produce an alginate/polyvinyl alcohol/ciprofloxacin wound patch to enable controlled delivery of the miRs without cellular attachment to the wound with the added benefit of anti-microbial activity. Application of the nanofibre patch loaded with the blended RALA/miR nanoparticles demonstrated a synergistic effect with acceleration of wound closure rate, a significant increase in epidermal thickness and blood vessel count with respect to commercial and untreated controls.

Lipoic Acid Conjugated Boron Hybrids Enhance Wound Healing and Antimicrobial Processes

Complications of chronic non-healing wounds led to the emergence of nanotechnology-based therapies to enhance healing, facilitate tissue repair, and prevent wound-related complications like infections. Here, we design alpha lipoic acid (ALA) conjugated hexagonal boron nitride (hBN) and boron carbide (B₄C) nanoparticles (NPs) to enhance wound healing in human dermal fibroblast (HDFa) cell culture and characterize its antimicrobial properties against Staphylococcus aureus (S. aureus, gram positive) and Escherichia coli (E. coli, gram negative) bacterial strains. ALA molecules are integrated onto hBN and C₄B NPs through esterification procedure, and molecular characterizations are performed by using transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and UV-vis spectroscopy. Wound healing and antimicrobial properties are investigated via the use of cell viability assays, scratch test, oxidative stress, and antimicrobial activity assays. Based on our analysis, we observe that ALA-conjugated hBN NPs have the highest wound-healing feature and antimicrobial activity compared to ALA-B₄C. On the other hand, hBN, ALA-B₄C, and ALA compounds showed promising regenerative and antimicrobial properties. Also, we find that ALA conjugation enhances wound healing and antimicrobial potency of hBN and B₄C NPs. We conclude that the ALA-hBN conjugate is a potential candidate to stimulate regeneration process for injuries.

A critical review on nanomaterial based therapeutics for diabetic wound healing

Diabetes mellitus is a chronic endocrine disease that occurs mostly in the state of hyperglycemia (elevated blood glucose level). In the recent times, diabetes is listed under world's utmost critical health issues. Wound treatment procedures are complicated in diabetic individuals all over the world. Diabetic wound care not only involves high-cost, but also the primary cause of hospitalization, which can lead to amputation thereby reducing diabetic patient life expectancy. To lower the risk of amputation, wound healing requires the development of effective treatments. Traditional management systems for Diabetes are frequently chastised due to their high costs, difficulties in maintaining a sustainable supply chain and limited disposal alternatives. The worrisome rise in diabetes prevalence has sparked a surge of interest in the discovery of viable remedies to supplement existing treatments. Nanomaterials wound healing has a lot of potential for treating and preventing wound infections and it has recently gained popularity owing to its ability to transport drugs to the wound area in a regulated fashion, potentially overpowering the limits of traditional approaches. This research assessed several nanosystems, such as nanocarriers and nanotherapeutics, to explore how they can benefit in diabetic wound healing, with a focus on current obstacles and future prospects.

A Review on Chitosan and Cellulose Hydrogels for Wound Dressings

Wound management remains a challenging issue around the world, although a lot of wound dressing materials have been produced for the treatment of chronic and acute wounds. Wound healing is a highly dynamic and complex regulatory process that involves four principal integrated phases, including hemostasis, inflammation, proliferation, and remodeling. Chronic non-healing wounds are wounds that heal significantly more slowly, fail to progress to all the phases of the normal wound healing process, and are usually stalled at the inflammatory phase. These wounds cause a lot of challenges to patients, such as severe emotional and physical stress and generate a considerable financial burden on patients and the general public healthcare system. It has been reported that about 1-2% of the global population suffers from chronic non-healing wounds during their lifetime in developed nations. Traditional wound dressings are dry, and therefore cannot provide moist environment for wound healing and do not possess antibacterial properties. Wound dressings that are currently used consist of bandages, films, foams, patches and hydrogels. Currently, hydrogels are gaining much attention as a result of their water-holding capacity, providing a moist wound-healing milieu. Chitosan is a biopolymer that has gained a lot of attention recently in the pharmaceutical industry due to its unique chemical and antibacterial nature. However, with its poor mechanical properties, chitosan is incorporated with other biopolymers, such as the cellulose of desirable biocompatibility, at the same time having the improved mechanical and physical properties of the hydrogels. This review focuses on the study of biopolymers, such as cellulose and chitosan hydrogels, for wound treatment.

Platelet-rich plasma: a comparative and economical therapy for wound healing and tissue regeneration

Rise in the incidences of chronic degenerative diseases with aging makes wound care a socio-economic burden and unceasingly necessitates a novel, economical, and efficient wound healing treatment. Platelets have a crucial role in hemostasis and thrombosis by modulating distinct mechanistic phases of wound healing, such as promoting and stabilizing the clot. Platelet-rich plasma (PRP) contains a high concentration of platelets than naïve plasma and has an autologous origin with no immunogenic adverse reactions. As a consequence, PRP has gained significant attention as a therapeutic to augment the healing process. Since the past few decades, a robust volume of research and clinical trials have been performed to exploit extensive role of PRP in wound healing/tissue regeneration. Despite these rigorous studies and their application in diversified medical fields, efficacy of PRP-based therapies is continuously questioned owing to the paucity of large samplesizes, controlled clinical trials, and standard protocols. This review systematically delineates the process of wound healing and involvement of platelets in tissue repair mechanisms. Additionally, emphasis is laid on PRP, its preparation methods, handling, classification,application in wound healing, and PRP as regenerative therapeutics combined with biomaterials and mesenchymal stem cells (MSCs).

Determination of the effectiveness of Dorema ammoniacum gum on wound healing: an experimental study

OBJECTIVE

For a long time, natural compounds have been used to accelerate wound healing. In this study, the topical effects of ammoniacum gum extract on wound healing were investigated in white male rats.

METHOD

Following skin wound induction in aseptic conditions, 48 Wistar rats were divided into six equal groups; phenytoin cream 1% (standard), untreated (control), Eucerin (control), and 5%, 10% and 20% ointments of Dorema ammoniacum gum extract (treatment groups). All experimental groups received topical drugs daily for 14 days. The percentage of wound healing, hydroxyproline content, histological parameters, and growth factors (endothelial growth factor (EGF), platelet-derived growth factor (PDGF), vascular endothelial growth factor (VEGF) and transforming growth factor (TGF)-α) were measured in experimental groups.

RESULTS

The areas of the wounds in the treatment groups were significantly decreased compared with the wound areas of control groups at 5, 7 and 10 days after wounding. On the 12th day, the wounds in the treatment groups were completely healed. Hydroxyproline contents were significantly increased in the treatment groups compared with the control groups (p<0.001). In histological evaluation, the re-epithelialisation, increasing thickness of the epithelial layer, granulation tissue and neovascularisation parameters in the treatment groups showed significant increases compared with the control groups. Also, serum levels of TGF-β, PDGF, EGF and VEGF in the treatment groups were significantly increased compared to the control groups.

CONCLUSION

The topical application of ammoniacum gum extract significantly increases the percentage of wound healing in rats and reduces the time of wound closure.

Role of Exosomes in Pharyngucutaneous Fistula After Total Laryngectomy

Pharyngocutaneous fistula is the most common complication after total laryngectomy and is difficult to heal. Although conservative treatment and surgical repair are effective, they often take longer and additional trips to the operating room, which undoubtedly increases the financial burden on patients. Especially in combination with diseases such as diabetes and hypertension, which affect the efficacy of surgery. Adding growth factors into the repair material can promote fibroblast proliferation, angiogenesis, and accelerate wound healing. A substantial number of studies have shown that a type of nanoscale extracellular vesicle, called exosomes, facilitates organization repair by promoting blood vessel production, protein polysaccharides, and collagen deposition, thereby representing a new type of cellular therapy. At present, there is little research on the application of exosomes in pharyngocutaneous fistula regeneration after total laryngectomy. In this review, we summarize the biological characteristics of exosomes and their application in biomedical science, and highlight their application prospects in pharyngocutaneous fistula regeneration after total laryngectomy.

Biogenic Synthesis of Gold Nanoparticles from Physalis peruviana and Application in Wound Healing

Wound management is key to healing. Poorly managed wounds lead to abnormal biological reactions and complications. Microorganisms, bacteria or fungi, infect such wounds leading to their chronic nature. Gold nanoparticles (Au NPs) show wound healing properties. In addition, ethnobotanical information from Siaya County in Kenya shows the leaves of Physalis peruviana L. to be effective in wound management. A combination of Au NPs and leave extracts of Physalis peruviana L. through a one pot biogenic synthesis leads to a new effective wound management substance. The synthesis was done at room temperature 25°C and at 85°C. The UV-visible spectroscopy results show efficient sharper plasmon bands with a blue shift indicating a decrease in λ max compared to red shift which show an increase in λ max. The surface plasmon resonance is a sharper at wavelength of about 540 nm. Dynamic light scattering and zeta potential analysis show that the polydispersity index is high and this is attributed to heterogeneity of chemical components of the plants. Transmission electron microscopy results for Au NPs show similarity in their shapes and sizes with grain size boundaries of between 1 nm and 100 nm. The particles are spherically shaped and crystalline with small lattice due to the small grains. The gold nanoparticles synthesized from Physalis peruviana show antimicrobial activities against gram-positive bacteria and, gram-negative bacteria as well as gram-positive fungus. The inhibition zones for Au NPs of different concentrations vary significantly between concentrations (one-way ANOVA at $P<0.05$ ). The highest antibacterial activity is at 100 mM of Au NPs against Escherichia coli, Bacillus subtilis, and Staphylococcus aureus. The inhibition zones for Au NPs at concentration of 100 mM and Physalis peruviana extract vary significantly in all the microbial cells, except for Pseudomonas aeruginosa (one-way ANOVA, F(3,11) = 2.67, $P=0.1189$ ). Application of the Au NPs in wound healing is faster than controls. The Au NPs also have good biocompatibility as signs of infection were not present.

Silver Nanoparticles and Its Mechanistic Insight for Chronic Wound Healing: Review on Recent Progress

Wounds are structural and functional disruptions of skin that occur because of trauma, surgery, acute illness, or chronic disease conditions. Chronic wounds are caused by a breakdown in the finely coordinated cascade of events that occurs during healing. Wound healing is a long process that split into at least three continuous and overlapping processes: an inflammatory response, a proliferative phase, and finally the tissue remodeling. Therefore, these processes are extensively studied to develop novel therapeutics in order to achieve maximum recovery with minimum scarring. Several growth hormones and cytokines secreted at the site of lesions tightly regulates the healing processes. The traditional approach for wound management has been represented by topical treatments. Metal nanoparticles (e.g., silver, gold and zinc) are increasingly being employed in dermatology due to their favorable effects on healing, as well as in treating and preventing secondary bacterial infections. In the current review, a brief introduction on traditional would healing approach is provided, followed by focus on the potential of wound dressing therapeutic techniques functionalized with Ag-NPs.

Wound healing efficacy of novel ayurveda formulation- Pentabark Kashaya: In wistar rats using excision wound model- an in vivo study

BACKGROUND

Wound healing plays a major concern in the field of surgery as it requires uneventful healing. Management aims towards prevention of infection and to accelerate healing. Acharya Sushruta has given more emphasis on Vrana (wound) and its chikitsa (treatment). Many antiseptic agents which prevent infection are widely used but have no role in accelerating the healing process and are cytotoxic, deleterious to wound healing. In this regard an innovative polyherbomineral formulation Pentabark Kashaya (PK)was formulated to assess acute dermal toxicity and woundhealing activity.

OBJECTIVE

To explore the wound healing efficacy of novel Ayurveda Formulation i.e Pentabark Kashaya in Wistar rats using the excision wound model.

MATERIALS AND METHOD

Acute dermal toxicity study was carried out on five female Wistar rats by following the OECD guideline 434 and signs of toxicity were assessed for the period of 14 days. Wound healing activitywas assessed on the excision wound model. 18 male Wistar rats were procured for the study and divided into three groups (n = 6 in each group). The test group was treated with application of PK, standard group with Povidone iodine solution 5% and control group with distilled water. The parameters assessed were epithelialization period, wound contraction rate, wound closure day and swab test for microbial load for the period of 21 days. Statistical analysis was done by using one way ANOVA and Tukeys HSD to assess changes in between three groups at each time point.

RESULTS

No signs of acute dermal toxicity were seen, which proved that PK is safe for application. Significant results were seen in the parameters of wound healing like period of epithelialization and wound closure day. Percentage of wound contraction rate was increased in test group when compared to other groups. Histopathology of skin showed marked changes in re-epithelialization, dermal fibroblast, dermal fibrocytes in test group when compared to control group.

CONCLUSION

PK is safe for application and it is effective in wound healing.

CLINICAL TRIAL REGISTRATION NO

Not applicable.

The Role of the Extracellular Matrix (ECM) in Wound Healing: A Review

The extracellular matrix (ECM) is a 3-dimensional structure and an essential component in all human tissues. It is comprised of varying proteins, including collagens, elastin, and smaller quantities of structural proteins. Studies have demonstrated the ECM aids in cellular adherence, tissue anchoring, cellular signaling, and recruitment of cells. During times of integumentary injury or damage, either acute or chronic, the ECM is damaged. Through a series of overlapping events called the wound healing phases—hemostasis, inflammation, proliferation, and remodeling—the ECM is synthesized and ideally returned to its native state. This article synthesizes current and historical literature to demonstrate the involvement of the ECM in the varying phases of the wound healing cascade.

Phytochemistry and Biological Activity of Medicinal Plants in Wound Healing: An Overview of Current Research

Wound healing is a complicated process, and the effective management of wounds is a major challenge. Natural herbal remedies have now become fundamental for the management of skin disorders and the treatment of skin infections due to the side effects of modern medicine and lower price for herbal products. The aim of the present study is to summarize the most recent in vitro, in vivo, and clinical studies on major herbal preparations, their phytochemical constituents, and new formulations for wound management. Research reveals that several herbal medicaments have marked activity in the management of wounds and that this activity is ascribed to flavonoids, alkaloids, saponins, and phenolic compounds. These phytochemicals can act at different stages of the process by means of various mechanisms, including anti-inflammatory, antimicrobial, antioxidant, collagen synthesis stimulating, cell proliferation, and angiogenic effects. The application of natural compounds using nanotechnology systems may provide significant improvement in the efficacy of wound treatments. Increasing the clinical use of these therapies would require safety assessment in clinical trials.

In vitro study of the mesenchymal stem cells-conditional media role in skin wound healing process: A systematic review

Mesenchymal stromal cell (MSC)-conditioned medium (CM) offers a potential opportunity in the skin wound healing treatment. In this systematic review, an overview of the knowledge on this topic has been provided. A multistep search of the PubMed, Scopus and Science Direct database has been performed to identify papers on MSCs-conditional media used in skin wound healing. Eligibility checks were performed based upon predefined selection criteria. Of the 485 articles initially identified, consequently, only 96 articles apparently related to MSC-conditional media were initially assessed for eligibility. Finally, the 32 articles, strictly regarding the in vitro use of MSCs-conditional media in skin wounds, were analysed. The information analysed highlights the efficacy of MSCs-conditional media on skin wound healing in vitro models. The outcome of this review may be used to guide pre-clinical and clinical studies on the role of MSCs-conditional media in skin wound healing.

Cotton Cellulose-Derived Hydrogel and Electrospun Fiber as Alternative Material for Wound Dressing Application

Cotton has been recognized as a useful biomaterial over decades, and it has been widely applied in the textile industry. However, a large amount of cotton waste is generated during the manufacturing processes, but it has been considered as a low-value product. With high content of cellulose remaining in cotton waste, our study focuses on transforming cotton cellulose into a valuable product. Cellulose was extracted from cotton waste and modified into two main materials for wound dressing application: hydrogel-based water absorbent materials and electrospun composite nanofibers. In order to enhance the water absorption, carboxymethyl cellulose (CMC), the modified cellulose with functional group prone to interact with water molecules, has been developed in this study. The hydrogel-based CMC was created by using the chemical cross-linking reaction of epichlorohydrin (ECH). The hydrogel demonstrated the swelling and reswelling ability by 1718 ± 137% and 97.95 ± 9.76%, respectively. Meanwhile, cellulose/PEG in trifluoroacetic acid (TFA) was successfully fabricated as nonwoven composite by a conventional electrospinning technique. The fabrics provided highly appropriated properties as wound dressing, including the following: water absorption was up to 1300 times and water vapor permeability controlled in the range of 2163–2285 g·m⁻²·day⁻¹. This showed the preliminary information for recovering cotton waste into valuable products.

3D nanocomposite scaffold of TiO2-nanotube-incorporated carrageenan for wound healing

Three-dimensional (3D) nanocomposite scaffold is an important material for biomedical application owing to their compatibility and effectiveness compared with other types of nanocomposites. In this research, a unique 3D nanocomposite scaffold based on carrageenan biopolymer incorporating titanium dioxide (TiO2) nanotubes (TiO2NTs) was successfully developed. Fourier transform infrared spectroscopy and X-ray powder diffraction were employed to investigate the intermolecular interaction and phase structure of the fabricated 3D TiO2NT-incorporated carrageenan (TiO2NT/CG) nanocomposite scaffold. The ability of 3D TiO2NT/CG nanocomposite scaffold for wound healing was tested in vitro and in vivo. The in vitro study on 3T3 mouse fibroblast cells demonstrated that the number of cells increased up to 190 000 per well. Meanwhile, in vivo studies on Sprague Dawley rat exhibited that a 100% cure rate of wounds was observed after 14 days. These are attributed to the presence of ∼10 nm TiO2NTs that are homogeneously distributed onto the scaffold, as proven by scanning electron microscopy. The TiO2NTs promote wound healing by generating reactive oxygen species to induce the fibroblast growth factor and for the formation of a new extracellular matrix. The interconnected porous structure and rough surface of the 3D titanium dioxide/CG nanocomposite scaffold also support cell proliferation to expedite wound healing, thus offering a good candidate for wound-dressing application.

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.

Molecular Mechanism of Traditional Chinese Ointment of Xuzhou Qufu Shengji in Infected Wounds

Background

Xuzhou Qufu Shengji Ointment (QFSJO) has been used in hospital and private medication for more than 30 years to treat the infective wounds after trauma. However, molecular investigation is lacking. This study used rats to explore the healing mechanism of QFSJO in promoting wound healing in human.

Methods

One circular incision was individually generated on the back of 30 rats in three groups and challenged with 10⁸ CFU (0.3 mL) of Staphylococcus aureus. Then, one of the trauma groups was treated with QFSJO gauze, and the control group was covered with a piece of Vaseline gauze, while the western medicine group was treated with erythromycin in a similar way. The dressing change of all the groups was performed once a day for three weeks. The anti-inflammation and proangiogenesis of QFSJO were evaluated by enzyme-linked immunosorbent assay (ELISA). The levels of angiogenesis associated factors, vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF), hydroxyproline, and hemoglobin, were measured according to ELISA. The immunohistochemistry of CD31 and CD34 expression in granulation tissue was demonstrated and quantitatively analyzed for angiogenesis in granulation tissue in sites.

Results

A faster wound healing ratio was observed in QFSJO-dressing-treated group than Vaseline- and erythrocin-treated groups. ELISA results showed that QFSJO promoted VEGF and b-FGF levels significantly in early stage of wound healing. QFSJO dressing group also showed an enhanced hydroxyproline and hemoglobin in granulation tissue. The expressions of CD31 and CD34 in granulation tissue of QFSJO group were higher than in the Vaseline and erythrocin groups.

Conclusion

QFSJO improved the healing rate of the infective wounds by promoting the angiogenesis of granulation tissue and inhibiting the inflammation of the trauma tissue. Our finding suggests that QFSJO is able to help angiogenic capillary sprouts for collagen accumulates in the granulation tissue.