Pullulan-Collagen Hydrogel Wound Dressing Promotes Dermal Remodeling and Wound Healing Compared to Commercially Available Collagen Dressings

A bioactive composite sponge based on biomimetic collagen fibril and oxidized alginate for noncompressible hemorrhage and wound healing

The study focuses on developing a bioactive shape memory sponge to address the urgent demand for short-term rapid hemostasis and long-term wound healing in noncompressible hemorrhage cases. A composite sponge was created by spontaneously generating pores and double cross-linking under mild conditions using biomimetic collagen fibril (BCF) and oxidized alginate (OA) as natural backbone, combined with an inert calcium source (Ca) from CaCO3-GDL slow gelation mechanism. The optimized BCF/OACa (5/5) sponge efficiently absorbed blood after compression and recovered to its original state within 11.2 ± 1.3 s, achieving physical hemostatic mechanism. The composite sponge accelerated physiological coagulation by promoting platelet adhesion and activation through BCF, as well as enhancing endogenous and exogenous hemostatic pathways by Ca2+. Compared to commercial PVA expanding hemostatic sponge, the composite sponge reduced bleeding volume and shortened hemostasis time in rat liver injury pick and perforation wound models. Additionally, it stimulated fibroblast migration and differentiation, thus promoting wound healing. It is biodegradable with low inflammatory response and promotes granulation tissue regeneration. In conclusion, this biocomposite sponge provides multiple hemostatic pathways and biochemical support for wound healing, is biologically safe and easy to fabricate, process and use, with significant potential for clinical translation and application.

Potential of Pullulan-Based Polymeric Nanoparticles for Improving Drug Physicochemical Properties and Effectiveness

Pullulan, a natural polysaccharide with unique biocompatibility and biodegradability, has gained prominence in nanomedicine. Its application in nanoparticle drug delivery systems showcases its potential for precision medicine.

AIM OF STUDY

This scientific review aims to comprehensively discuss and summarize recent advancements in pullulan-based polymeric nanoparticles, focusing on their formulation, characterization, evaluation, and efficacy.

METHODOLOGY

A search on Scopus, PubMed, and Google Scholar, using "Pullulan and Nanoparticle" as keywords, identified relevant articles in recent years.

RESULTS

The literature search highlighted a diverse range of studies on the pullulan-based polymeric nanoparticles, including the success of high-selectivity hybrid pullulan-based nanoparticles for efficient boron delivery in colon cancer as the active targeting nanoparticle, the specific and high-efficiency release profile of the development of hyalgan-coated pullulan-based nanoparticles, and the design of multifunctional microneedle patches that incorporated pullulan-collagen-based nanoparticle-loaded antimicrobials to accelerate wound healing. These studies collectively underscore the versatility and transformative potential of pullulan-based polymeric nanoparticles in addressing biomedical challenges.

CONCLUSION

Pullulan-based polymeric nanoparticles are promising candidates for innovative drug delivery systems, with the potential to overcome the limitations associated with traditional delivery methods.

Current progress of protein-based dressing for wound healing applications - A review

Protein-based wound dressings have garnered increasing interest in recent years owing to their distinct physical, chemical, and biological characteristics. The intricate molecular composition of proteins gives rise to unique characteristics, such as exceptional biocompatibility, biodegradability, and responsiveness, which contribute to the promotion of wound healing. Wound healing is an intricate and ongoing process influenced by multiple causes, and it consists of four distinct phases. Various treatments have been developed to repair different types of skin wounds, thanks to advancements in medical technology and the recognition of the diverse nature of wounds. This review has literature reviewed within the last 3-5 years-the recent progress and development of protein in wound dressings and the fundamental properties of an ideal wound dressing. Herein, the recent strides in protein-based state-of-the-art wound dressing emphasize the significant challenges and summarize future perspectives for wound healing applications.

Strategies to enhance the efficacy of FGF2-based therapies for skin wound healing

Basic fibroblast growth factor (FGF2 or bFGF) is critical for optimal wound healing. Experimental studies show that local application of FGF2 is a promising therapeutic approach to stimulate tissue regeneration, including for the treatment of chronic wounds that have a low healing potential or are characterised by a pathologically altered healing process. However, the problem of low efficiency of growth factors application due to their rapid loss of biological activity in the aggressive proteolytic environment of the wound remains. Therefore, ways to preserve the efficacy of FGF2 for wound treatment are being actively developed. This review considers the following strategies to improve the effectiveness of FGF2-based therapy: (1) use of vehicles/carriers for delivery and gradual release of FGF2; (2) chemical modification of FGF2 to increase the stability of the molecule; (3) use of genetic constructs encoding FGF2 for de novo synthesis of protein in the wound. In addition, this review discusses FGF2-based therapeutic strategies that are undergoing clinical trials and demonstrating the efficacy of FGF2 for skin wound healing.

Biopolymer based nanoparticles and their therapeutic potential in wound healing - A review

Nanoparticles (NPs) have been extensively investigated for their potential in nanomedicine. There is a significant level of enthusiasm about the potential of NPs to bring out a transformative impact on modern healthcare. NPs can serve as effective wound dressings or delivery vehicles due to their antibacterial and pro-wound-healing properties. Biopolymer-based NPs can be manufactured using various food-grade biopolymers, such as proteins, polysaccharides, and synthetic polymers, each offering distinct properties suitable for different applications which include collagen, polycaprolactone, chitosan, alginate, and polylactic acid, etc. Their biodegradable and biocompatible nature renders them ideal nanomaterials for applications in wound healing. Additionally, the nanofibers containing biopolymer-based NPs have shown excellent anti-bacterial and wound healing activity like silver NPs. These NPs represent a paradigm shift in wound healing therapies, offering targeted and personalized solutions for enhanced tissue regeneration and accelerated wound closure. The current review focuses on biopolymer NPs with their applications in wound healing.

Preparation and Application of Hemostatic Hydrogels

Hemorrhage remains a critical challenge in various medical settings, necessitating the development of advanced hemostatic materials. Hemostatic hydrogels have emerged as promising solutions to address uncontrolled bleeding due to their unique properties, including biocompatibility, tunable physical characteristics, and exceptional hemostatic capabilities. In this review, a comprehensive overview of the preparation and biomedical applications of hemostatic hydrogels is provided. Particularly, hemostatic hydrogels with various materials and forms are introduced. Additionally, the applications of hemostatic hydrogels in trauma management, surgical procedures, wound care, etc. are summarized. Finally, the limitations and future prospects of hemostatic hydrogels are discussed and evaluated. This review aims to highlight the biomedical applications of hydrogels in hemorrhage management and offer insights into the development of clinically relevant hemostatic materials.

Biological scaffold as potential platforms for stem cells: Current development and applications in wound healing

Wound repair is a complex challenge for both clinical practitioners and researchers. Conventional approaches for wound repair have several limitations. Stem cell-based therapy has emerged as a novel strategy to address this issue, exhibiting significant potential for enhancing wound healing rates, improving wound quality, and promoting skin regeneration. However, the use of stem cells in skin regeneration presents several challenges. Recently, stem cells and biomaterials have been identified as crucial components of the wound-healing process. Combination therapy involving the development of biocompatible scaffolds, accompanying cells, multiple biological factors, and structures resembling the natural extracellular matrix (ECM) has gained considerable attention. Biological scaffolds encompass a range of biomaterials that serve as platforms for seeding stem cells, providing them with an environment conducive to growth, similar to that of the ECM. These scaffolds facilitate the delivery and application of stem cells for tissue regeneration and wound healing. This article provides a comprehensive review of the current developments and applications of biological scaffolds for stem cells in wound healing, emphasizing their capacity to facilitate stem cell adhesion, proliferation, differentiation, and paracrine functions. Additionally, we identify the pivotal characteristics of the scaffolds that contribute to enhanced cellular activity.

Avenanthramide and β-Glucan Therapeutics Accelerate Wound Healing Via Distinct and Nonoverlapping Mechanisms

Objective: Given the significant economic, health care, and personal burden of acute and chronic wounds, we investigated the dose dependent wound healing mechanisms of two Avena sativa derived compounds: avenanthramide (AVN) and β-Glucan. Approach: We utilized a splinted excisional wound model that mimics human-like wound healing and performed subcutaneous AVN and β-Glucan injections in 15-week-old C57BL/6 mice. Histologic and immunohistochemical analysis was performed on the explanted scar tissue to assess changes in collagen architecture and cellular responses. Results: AVN and β-Glucan treatment provided therapeutic benefits at a 1% dose by weight in a phosphate-buffered saline vehicle, including accelerated healing time, beneficial cellular recruitment, and improved tissue architecture of healed scars. One percent AVN treatment promoted an extracellular matrix (ECM) architecture similar to unwounded skin, with shorter, more randomly aligned collagen fibers and reduced inflammatory cell presence in the healed tissue. One percent β-Glucan treatment promoted a tissue architecture characterized by long, thick bundles of collagen with increased blood vessel density. Innovation: AVN and β-Glucan have previously shown promise in promoting wound healing, although the therapeutic efficacies and mechanisms of these bioactive compounds remain incompletely understood. Furthermore, the healed ECM architecture of these wounds has not been characterized. Conclusions: AVN and β-Glucan accelerated wound closure compared to controls through distinct mechanisms. AVN-treated scars displayed a more regenerative tissue architecture with reduced inflammatory cell recruitment, while β-Glucan demonstrated increased angiogenesis with more highly aligned tissue architecture more indicative of fibrosis. A deeper understanding of the mechanisms driving healing in these two naturally derived therapeutics will be important for translation to human use.

Bringing innovative wound care polymer materials to the market: Challenges, developments, and new trends

The development of innovative products for treating acute and chronic wounds has become a significant topic in healthcare, resulting in numerous products and innovations over time. The growing number of patients with comorbidities and chronic diseases, which may significantly alter, delay, or inhibit normal wound healing, has introduced considerable new challenges into the wound management scenario. Researchers in academia have quickly identified promising solutions, and many advanced wound healing materials have recently been designed; however, their successful translation to the market remains highly complex and unlikely without the contribution of industry experts. This review article condenses the main aspects of wound healing applications that will serve as a practical guide for researchers working in academia and industry devoted to designing, evaluating, validating, and translating polymer wound care materials to the market. The article highlights the current challenges in wound management, describes the state-of-the-art products already on the market and trending polymer materials, describes the regulation pathways for approval, discusses current wound healing models, and offers a perspective on new technologies that could soon reach consumers. We envision that this comprehensive review will significantly contribute to highlighting the importance of networking and exchanges between academia and healthcare companies. Only through the joint of these two actors, where innovation, manufacturing, regulatory insights, and financial resources act in harmony, can wound care products be developed efficiently to reach patients quickly and affordably.

Developing natural polymers for skin wound healing

Natural polymers are complex organic molecules that occur in the natural environment and have not been subjected to artificial synthesis. They are frequently encountered in various creatures, including mammals, plants, and microbes. The aforementioned polymers are commonly derived from renewable sources, possess a notable level of compatibility with living organisms, and have a limited adverse effect on the environment. As a result, they hold considerable significance in the development of sustainable and environmentally friendly goods. In recent times, there has been notable advancement in the investigation of the potential uses of natural polymers in the field of biomedicine, specifically in relation to natural biomaterials that exhibit antibacterial and antioxidant characteristics. This review provides a comprehensive overview of prevalent natural polymers utilized in the biomedical domain throughout the preceding two decades. In this paper, we present a comprehensive examination of the components and typical methods for the preparation of biomaterials based on natural polymers. Furthermore, we summarize the application of natural polymer materials in each stage of skin wound repair. Finally, we present key findings and insights into the limitations of current natural polymers and elucidate the prospects for their future development in this field.

Collagen-Based Medical Devices for Regenerative Medicine and Tissue Engineering

Assisted reproductive technologies are key to solving the problems of aging and organ defects. Collagen is compatible with living tissues and has many different chemical properties; it has great potential for use in reproductive medicine and the engineering of reproductive tissues. It is a natural substance that has been used a lot in science and medicine. Collagen is a substance that can be obtained from many different animals. It can be made naturally or created using scientific methods. Using pure collagen has some drawbacks regarding its physical and chemical characteristics. Because of this, when collagen is processed in various ways, it can better meet the specific needs as a material for repairing tissues. In simpler terms, collagen can be used to help regenerate bones, cartilage, and skin. It can also be used in cardiovascular repair and other areas. There are different ways to process collagen, such as cross-linking it, making it more structured, adding minerals to it, or using it as a carrier for other substances. All of these methods help advance the field of tissue engineering. This review summarizes and discusses the current progress of collagen-based materials for reproductive medicine.

Keratin- and VEGF-Incorporated Honey-Based Sponge-Nanofiber Dressing: An Ideal Construct for Wound Healing

To overcome the drawbacks of single-layered wound dressings, bilayer dressings are now introduced as an alternative to achieve effective and long-term treatment. Here, a bilayer dressing composed of electrospun nanofibers in the bottom layer (BL) and a sponge structure as the top layer (TL) is presented. Hydrophilic poly(acrylic acid) (PAAc)-honey (Hny) with interconnected pores of 76.04 μm was prepared as the TL and keratin (Kr), Hny, and vascular endothelial growth factor (VEGF) were prepared as the BL. VEGF indicates a gradual release over 7 days, promoting angiogenesis, as proven by the chick chorioallantoic membrane assay and in vivo tissue histomorphology observation. Additionally, the fabricated dressing material indicated a satisfactory tensile profile, cytocompatibility for human keratinocyte cells, and the ability to promote cell attachment and migration. The in vivo animal model demonstrated that the full-thickness wound healed faster when it was covered with PAAc-Hny/Hny-Kr-VEGF than in other groups. Additionally, faster blood vessel formation, collagen synthetization, and epidermal layer generation were also confirmed, which have proven efficient healing acceleration in wounds treated with synthesized bilayer dressings. Our findings indicated that the fabricated material can be promising as a functional wound dressing.

Curcumin-loaded methacrylate pullulan with grafted carboxymethyl-β-cyclodextrin to form hydrogels for wound healing: In vitro evaluation

A pullulan (Pul)-derivative hydrogel was developed by introducing methacrylate (MA) groups and β-cyclodextrin (βCD) to form a Pul-βCD-MA hydrogel by UV cross-linking. The MA was expected to improve the hydrogel's mechanical properties and the βCD to increase the solubility of curcumin. Pul-βCD-MA was successfully synthesized, as confirmed by the 1H NMR and FTIR spectra. Hydrogels were formed at Pul-βCD-MA concentrations of 5 %, 7.5 %, or 10 % w/v. Pul-βCD-MA showed enhanced curcumin solubility compared to Pul or Pul-MA. The morphological analysis of the hydrogel showed a porous structure. The concentration of βCD affected the hydrogels' mechanical properties, and the 7.5 % hydrogel (with or without curcumin) did not fracture. The cumulative release of curcumin in the 7.5 % Pul-βCD-MA hydrogel was 60 % over 8 h. The release profile fit the Korsmeyer-Peppas model. In vitro cytotoxicity tests revealed that hydrogels were biocompatible with human primary dermal fibroblast cells. Curcumin-loaded Pul-βCD-MA hydrogels significantly accelerated wound healing compared to Pul-βCD-MA hydrogels without curcumin loading. Therefore, the Pul derivative's hydrogel may be a promising material for wound healing.

Preparation of Enzyme-Soluble Swim Bladder Collagen from Sea Eel (Muraenesox cinereus) and Evaluation Its Wound Healing Capacity

In the present research, the enzyme-facilitated collagen from sea eel (Muraenesox cinereus) swim bladder was isolated, and the collagen characteristics were analyzed. Then, the collagen sponge was prepared and its potential mechanism in promoting skin wound healing in mice was further investigated. Collagen was obtained from the swim bladder of sea eels employing the pepsin extraction technique. Single-factor experiments served as the basis for the response surface method (RSM) to optimize pepsin concentration, solid-liquid ratio, and hydrolysis period. With a pepsin concentration of 2067 U/g, a solid-liquid ratio of 1:83 g/mL, and a hydrolysis period of 10 h, collagen extraction achieved a yield of 93.76%. The physicochemical analysis revealed that the extracted collagen belonged to type I collagen, and the collagen sponge displayed a fibrous structure under electron microscopy. Furthermore, in comparison to the control group, mice treated with collagen sponge dressing exhibited elevated activities of superoxide dismutase (SOD), catalase (CAT), total antioxidant capacity (T-AOC), and glutathione peroxidase (GSH-Px), and decreased levels of malondialdehyde (MDA), interleukin (IL)-1β, interleukin (IL)-6, and tumor necrosis factor (TNF)-α. The collagen sponge dressing effectively alleviated inflammation in the wound area, facilitating efficient repair and rapid healing of the skin tissue. During the initial phase of wound healing, the group treated with collagen sponge dressing exhibited an enhancement in the expressions of cluster of differentiation (CD)31, epidermal growth factor (EGF), transforming growth factor (TGF)-β1, and type I collagen, leading to an accelerated rate of wound healing. In addition, this collagen sponge dressing could also downregulate the expressions of CD31, EGF, and type I collagen to prevent scar formation in the later stage. Moreover, this collagen treatment minimized oxidative damage and inflammation during skin wound healing and facilitated blood vessel formation in the wound. Consequently, it exhibits significant potential as an ideal material for the development of a skin wound dressing.

Animal tissue-derived biomaterials for promoting wound healing

The skin serves as the primary barrier between the human body and external environment, and is therefore susceptible to damage from various factors. In response to this challenge, animal tissue-derived biomaterials have emerged as promising candidates for wound healing due to their abundant sources, low side-effect profiles, exceptional bioactivity, biocompatibility, and unique extracellular matrix (ECM) mimicry. The evolution of modern engineering technology and therapies has allowed these animal tissue-derived biomaterials to be transformed into various forms and modified to possess the necessary properties for wound repair. This review provides an overview of the wound healing process and the factors that influence it. We then describe the extraction methods, important properties, and recent practical applications of various animal tissue-derived biomaterials. Our focus then shifts to the critical properties of these biomaterials in skin wound healing and their latest research developments. Finally, we critically examine the limitations and future prospects of biomaterials generated from animal tissues in this field.

Biochemical and histological insights of 1,4-polyisoprene isolated from Sphenocentrum jollyanum pierre (menispermaceae) stem in wound healing activity in streptozotocin-induced diabetic rats

ETHNOPHARMACOLOGICAL RELEVANCE

Sphenocentrum jollyanum whole stem extract is used traditionally in combination with its leaves to treat chronic wounds and also ameliorate conditions that exacerbate wounds such as diabetes mellitus.

AIM OF THE STUDY

The study isolated the major wound healing bioactive compound from the non-polar fraction of S. jollyanum extract and evaluated the in vivo wound healing activity of a 0.10% w/w 1,4-polyisoprene-based ointment in streptozotocin-induced diabetic rats.

MATERIALS AND METHODS

The major bioactive constituent of S. jollyanum was isolated using a wound healing activity-guided approach and characterized the compound using 1D and 2D-NMR spectroscopic techniques. The wound healing activity study adopted both excision (wound contraction) and incision (biochemical) models.

RESULTS

In the excision model, the 1,4-polyisoprene caused 99% wound closure and restored the excised wound on day 12. On the 6th and 12th post-wounding days, 1,4-polyisoprene caused a significant (p < 0.001) elevation in the tensile strength (486 g) of the incision wound compared with the control (388 g). The biochemical (hexosamine and hydroxyproline) and antioxidant/inflammatory (ascorbic acid, superoxide dismutase, and glutathione peroxidase) parameters increased significantly while malondialdehyde was down-regulated in the wounds treated with 1,4-polyisoprene compared with control. The histological analysis of tissue sections taken from the edge and center of the wounds at 0-12 days post wounding revealed an increased tissue regeneration, accelerated collagen formation, and epidermal regeneration without edema or inflammation on the 12th day.

CONCLUSION

The major wound healing constituent of S. jollyanum is 1,4-polyisoprene and the study has provided a new class of compounds for further optimization.

Microbial Exopolysaccharide Composites in Biomedicine and Healthcare: Trends and Advances

Microbial exopolysaccharides (EPSs), e.g., xanthan, dextran, gellan, curdlan, etc., have significant applications in several industries (pharma, food, textiles, petroleum, etc.) due to their biocompatibility, nontoxicity, and functional characteristics. However, biodegradability, poor cell adhesion, mineralization, and lower enzyme activity are some other factors that might hinder commercial applications in healthcare practices. Some EPSs lack biological activities that make them prone to degradation in ex vivo, as well as in vivo environments. The blending of EPSs with other natural and synthetic polymers can improve the structural, functional, and physiological characteristics, and make the composites suitable for a diverse range of applications. In comparison to EPS, composites have more mechanical strength, porosity, and stress-bearing capacity, along with a higher cell adhesion rate, and mineralization that is required for tissue engineering. Composites have a better possibility for biomedical and healthcare applications and are used for 2D and 3D scaffold fabrication, drug carrying and delivery, wound healing, tissue regeneration, and engineering. However, the commercialization of these products still needs in-depth research, considering commercial aspects such as stability within ex vivo and in vivo environments, the presence of biological fluids and enzymes, degradation profile, and interaction within living systems. The opportunities and potential applications are diverse, but more elaborative research is needed to address the challenges. In the current article, efforts have been made to summarize the recent advancements in applications of exopolysaccharide composites with natural and synthetic components, with special consideration of pharma and healthcare applications.

Nanosilver-functionalized polysaccharides as a platform for wound dressing

Polysaccharides that are naturally sourced have enormous promise as wound dressings, due to their wider availability and reasonable cost and good biocompatibility. Furthermore, nanosilver extensively applied in wound treatment is attributed to its broad spectrum of antimicrobial effects and lesser drug resistance. Consequently, wound dressings in corporating nanosilver have attracted wide-scale interest in wound healing, and nanosilver-functionalized polysaccharide-based wound dressings present an affordable option for healing of chronic wounds. This review encompasses preparation methods, classification, and antibacterial performances of nanosilver wound dressings. The prospective research arenas of nanosilver-based wound polysaccharide dressings are also elaborated. The review attempts to include a summary of the most recent advancements in silver nanotechnology as well as guidance for the investigation of nanosilver-functionalized polysaccharide-based wound dressings.

Pullulan-Based Hydrogels in Wound Healing and Skin Tissue Engineering Applications: A Review

Wound healing is a complex process of overlapping phases with the primary aim of the creation of new tissues and restoring their anatomical functions. Wound dressings are fabricated to protect the wound and accelerate the healing process. Biomaterials used to design dressing of wounds could be natural or synthetic as well as the combination of both materials. Polysaccharide polymers have been used to fabricate wound dressings. The applications of biopolymers, such as chitin, gelatin, pullulan, and chitosan, have greatly expanded in the biomedical field due to their non-toxic, antibacterial, biocompatible, hemostatic, and nonimmunogenic properties. Most of these polymers have been used in the form of foams, films, sponges, and fibers in drug carrier devices, skin tissue scaffolds, and wound dressings. Currently, special focus has been directed towards the fabrication of wound dressings based on synthesized hydrogels using natural polymers. The high-water retention capacity of hydrogels makes them potent candidates for wound dressings as they provide a moist environment in the wound and remove excess wound fluid, thereby accelerating wound healing. The incorporation of pullulan with different, naturally occurring polymers, such as chitosan, in wound dressings is currently attracting much attention due to the antimicrobial, antioxidant and nonimmunogenic properties. Despite the valuable properties of pullulan, it also has some limitations, such as poor mechanical properties and high cost. However, these properties are improved by blending it with different polymers. Additionally, more investigations are required to obtain pullulan derivatives with suitable properties in high quality wound dressings and tissue engineering applications. This review summarizes the properties and wound dressing applications of naturally occurring pullulan, then examines it in combination with other biocompatible polymers, such chitosan and gelatin, and discusses the facile approaches for oxidative modification of pullulan.

Nitric oxide-releasing gel accelerates healing in a diabetic murine splinted excisional wound model

Introduction

According to the American Diabetes Association (ADA), 9–12 million patients suffer from chronic ulceration each year, costing the healthcare system over USD $25 billion annually. There is a significant unmet need for new and efficacious therapies to accelerate closure of non-healing wounds. Nitric Oxide (NO) levels typically increase rapidly after skin injury in the inflammatory phase and gradually diminish as wound healing progresses. The effect of increased NO concentration on promoting re-epithelization and wound closure has yet to be described in the context of diabetic wound healing.

Methods

In this study, we investigated the effects of local administration of an NO-releasing gel on excisional wound healing in diabetic mice. The excisional wounds of each mouse received either NO-releasing gel or a control phosphate-buffered saline (PBS)-releasing gel treatment twice daily until complete wound closure.

Results

Topical administration of NO-gel significantly accelerated the rate of wound healing as compared with PBS-gel-treated mice during the later stages of healing. The treatment also promoted a more regenerative ECM architecture resulting in shorter, less dense, and more randomly aligned collagen fibers within the healed scars, similar to that of unwounded skin. Wound healing promoting factors fibronectin, TGF-β1, CD31, and VEGF were significantly elevated in NO vs. PBS-gel-treated wounds.

Discussion

The results of this work may have important clinical implications for the management of patients with non-healing wounds.

Combinational System of Lipid-Based Nanocarriers and Biodegradable Polymers for Wound Healing: An Updated Review

Skin wounds have imposed serious socioeconomic burdens on healthcare providers and patients. There are just more than 25,000 burn injury-related deaths reported each year. Conventional treatments do not often allow the re-establishment of the function of affected regions and structures, resulting in dehydration and wound infections. Many nanocarriers, such as lipid-based systems or biobased and biodegradable polymers and their associated platforms, are favorable in wound healing due to their ability to promote cell adhesion and migration, thus improving wound healing and reducing scarring. Hence, many researchers have focused on developing new wound dressings based on such compounds with desirable effects. However, when applied in wound healing, some problems occur, such as the high cost of public health, novel treatments emphasizing reduced healthcare costs, and increasing quality of treatment outcomes. The integrated hybrid systems of lipid-based nanocarriers (LNCs) and polymer-based systems can be promising as the solution for the above problems in the wound healing process. Furthermore, novel drug delivery systems showed more effective release of therapeutic agents, suitable mimicking of the physiological environment, and improvement in the function of the single system. This review highlights recent advances in lipid-based systems and the role of lipid-based carriers and biodegradable polymers in wound healing.

Protocol for the Splinted, Human-like Excisional Wound Model in Mice

While wound healing in humans occurs primarily through re-epithelization, in rodents it also occurs through contraction of the panniculus carnosus, an underlying muscle layer that humans do not possess. Murine experimental models are by far the most convenient and inexpensive research model to study wound healing, as they offer great variability in genetic alterations and disease models. To overcome the obstacle of contraction biasing wound healing kinetics, our group invented the splinted excisional wound model. While other rodent wound healing models have been used in the past, the splinted excisional wound model has persisted as the most used model in the field of wound healing. Here, we present a detailed protocol of updated and refined techniques necessary to utilize this model, generate results with high validity, and accurately analyze the collected data. This model is simple to conduct and provides an easy, standardizable, and replicable model of human-like wound healing.

Emerging Effects of Resveratrol on Wound Healing: A Comprehensive Review

Resveratrol (RSV) is a natural extract that has been extensively studied for its significant anti-inflammatory and antioxidant effects, which are closely associated with a variety of injurious diseases and even cosmetic medicine. In this review, we have researched and summarized the role of resveratrol and its different forms of action in wound healing, exploring its role and mechanisms in promoting wound healing through different modes of action such as hydrogels, fibrous scaffolds and parallel ratio medical devices with their anti-inflammatory, antioxidant, antibacterial and anti-ageing properties and functions in various cells that may play a role in wound healing. This will provide a direction for further understanding of the mechanism of action of resveratrol in wound healing for future research.

Murine macrophages or their secretome delivered in alginate dressings enhance impaired wound healing in diabetic mice

Diabetic foot ulceration is a devastating diabetic complication with unmet needs. We explored the efficacy of calcium-crosslinked alginate dressings in topically delivering primary macrophages and their secretome to diabetic wounds. The alginate bandages had a microporous structure that enabled even cell loading with prolonged cell survival and egress following wound placement. In vitro experiments showed that we could successfully differentiate and polarize primary murine bone marrow derived monocytes into M0, M1, M2a and M2c defined states with distinct gene expression, surface protein and secretome profiles. The primary macrophages were delivered in the bandages, migrated within the wounds and were still present for as long as 16 days post-injury. In wounds of db/db mice, treatment with all macrophage subtypes and their secretome, when compared to control, accelerated wound healing. Bulk RNA sequencing analysis and multiplex protein quantification of wound lysates revealed that M2c macrophages conditioned media had the most impact in wound healing affecting processes like neurogenesis, while M1 conditioned media promoted keratinization and epidermal differentiation. Collectively, our results indicate that alginate dressings can serve as a delivery platform for topical treatment of diabetic wounds and that conditioned media from distinctly polarized macrophages is equally or more effective than their parental cells in advancing wound healing and could therefore be a promising and technically advantageous alternative to cell therapy.

Disrupting mechanotransduction decreases fibrosis and contracture in split-thickness skin grafting

Burns and other traumatic injuries represent a substantial biomedical burden. The current standard of care for deep injuries is autologous split-thickness skin grafting (STSG), which frequently results in contractures, abnormal pigmentation, and loss of biomechanical function. Currently, there are no effective therapies that can prevent fibrosis and contracture after STSG. Here, we have developed a clinically relevant porcine model of STSG and comprehensively characterized porcine cell populations involved in healing with single-cell resolution. We identified an up-regulation of proinflammatory and mechanotransduction signaling pathways in standard STSGs. Blocking mechanotransduction with a small-molecule focal adhesion kinase (FAK) inhibitor promoted healing, reduced contracture, mitigated scar formation, restored collagen architecture, and ultimately improved graft biomechanical properties. Acute mechanotransduction blockade up-regulated myeloid CXCL10-mediated anti-inflammation with decreased CXCL14-mediated myeloid and fibroblast recruitment. At later time points, mechanical signaling shifted fibroblasts toward profibrotic differentiation fates, and disruption of mechanotransduction modulated mesenchymal fibroblast differentiation states to block those responses, instead driving fibroblasts toward proregenerative, adipogenic states similar to unwounded skin. We then confirmed these two diverging fibroblast transcriptional trajectories in human skin, human scar, and a three-dimensional organotypic model of human skin. Together, pharmacological blockade of mechanotransduction markedly improved large animal healing after STSG by promoting both early, anti-inflammatory and late, regenerative transcriptional programs, resulting in healed tissue similar to unwounded skin. FAK inhibition could therefore supplement the current standard of care for traumatic and burn injuries.