Transdermal deferoxamine administration improves excisional wound healing in chronically irradiated murine skin

Controlled release of deferiprone using iron-responsive nanoparticles integrated with dissolving microneedle for novel alternative treatments of β-thalassemia major

Iron chelating agents (ICs) such as conventional deferiprone are often ineffective when exposed to normal conditions due to their uncontrolled release when treating iron overload in ß-thalassemia major (ß-TM) due to the effects of blood transfusion. Iron deficiency and gastrointestinal side effects are crucial problems that can occur. Therefore, DFP was prepared as nanoparticles (NPs) coated with an iron-responsive (IR) polymer with an average particle size of 354.70 ± 10 nm to control its release. To facilitate optimal delivery, NP-IR-DFP was integrated into a dissolving microneedle (DMN) fabricated with biodegradable and biocompatible poly(vinylpyrrolidone) and poly(vinyl alcohol) polymers. The results showed that the NP-IR-DMN provided excellent insertion and mechanical strength and dissolved quickly after application. In vitro and ex-vivo studies revealed the more controllable release of NP-IR-DFP after integration with the DMN (NP-IR-DMN) for up to 24 h. Most importantly, the developed formula was hemocompatible and did not irritate the skin or cause tissue damage. Furthermore, the in vivo pharmacokinetics were further investigated for 24 h, which revealed short concentration (Cmax of 0.07 ± 0.03 μg/mL) and t1/2 (3.66 ± 0.76 h) under normal conditions and long-term iron overload-modeling conditions with Cmax (2.90 ± 0.14 μg/mL) and t1/2 (10.13 ± 1.00 h). This approach can extend beyond oral delivery by controlling the release of DFP, which can only be released in conditions of iron overload, and has the potential to prevent iron deficiency and excess, thus increasing the efficacy of DFP in β-TM therapy.

Deferoxamine-Loaded Trilayer Scaffold Containing Propolis and Sulfated Polysaccharides Promotes In Vivo Wound Healing through Angiogenesis Stimulation

The skin exhibits a hierarchical structure, and the application of tissue engineering techniques is recommended for the treatment of severe cutaneous injuries. To biologically mimic the structural characteristics of the distinct layers of the skin, the utilization of multilayered scaffolds has become a prominent approach. In the current study, an asymmetric trilayered scaffold was fabricated, consisting of a middle layer (ML) composed of 3D printed poly(vinyl alcohol)-carrageenan (PVA.Crg), a top layer (TL) of nanofibrous polycaprolactone-propolis (PCL.Pp), and a bottom layer (BL) of poly(vinyl alcohol)-fucoidan-deferoxamine (PVA.Fu.Def) nanofibers. It was indicated that the tensile strength and elastic modulus of the trilayer scaffold were significantly higher compared to other samples. The in vitro degradation rate of the studied scaffolds as well as the release of Def from the trilayer scaffold after 7 days were quantified within the range of 36-40 and 91.1%, respectively. The release of Def did not induce cytotoxicity and chicken chorioallantoic membrane assay revealed that the release of Def remarkably enhanced angiogenesis. Furthermore, the in vivo examinations exhibited the fastest re-epithelialization in the group treated with the trilayer scaffold containing Def. The findings of this study suggest the potential application of the fabricated trilayer scaffold as a skin substitute or wound dressing.

Electrospun PLGA/PCL Nanofiber Film Loaded with LPA Promotes Full-Layer Wound Healing by Regulating the Keratinocyte Pyroptosis

Electrospun nanofibers have a number of qualities that make them a suitable choice for skin wound healing. Lysophosphatidic acid (LPA) stimulates the keratinocytes and fibroblasts to proliferate, differentiate, and migrate and enhances skin wound healing. Here, we developed the electrospun scaffolds contained in polycaprolactone (PCL) and polylactic-co-glycolic acid (PLGA). The scaffolds loaded with LPA nanoparticles retained a porous nanofiber structure and showed better physicochemical properties and biocompatibility. The scaffold continuously releases LPA to quickly initiate cell signaling and maintain long-term anti-inflammatory activity. In this study, we found that PP scaffold with LPA reduces the disordered collagen deposition and the thickness of the newborn epidermis, improves skin healing, and reduces scar formation. Explaining the mechanism of LPA mineralized tissue regeneration in skin wound healing, LPA inhibited the pyroptosis of keratinocyte, a cell death process that induces inflammation and scar formation by inhibiting the expression of TNF-α and β-catenin proteins. Thus, the electrospun PP scaffold with LPA can be potentially developed as a therapeutic avenue to target skin wound healing.

A gelatin/acrylamide-based hydrogel for smart drug release monitoring and radiation-induced wound repair in breast cancer

Radiotherapy is a common local treatment for breast cancer, and while it is effective in targeting tumor cells, it inevitably causes significant side effects. These include excessive production of reactive oxygen species (ROS), repeated inflammatory, and severe skin ulceration, all of which can hinder the wound healing process. As a result, there is a pressing need for multifunctional medical dressings that can support wound repair following radiotherapy. In this study, we introduced a novel double-network interpenetrating hydrogel (GEMC), which combined gelatin grafted dopamine (GEDA), acrylamide, nano-clay (NC), and curcumin loaded nanoparticles (CCNPs). Unlike traditional single-function hydrogels, the GEMC hydrogel offered a combination of antioxidant properties, tissue adhesion, and real time drug tracking, effectively addressing the multifaceted challenges of wound healing after radiotherapy. The GEMC hydrogel exhibited impressive antioxidant activity and superior mechanical properties, which collectively improve the support and protection of wounded surfaces. Furthermore, GEMC promoted skin regeneration, angiogenesis and reduced inflammatory in a mouse model of radiotherapy-induced skin ulceration. These results highlight the hydrogel's potential to accelerate would healing and enhance the effectiveness of post-radiotherapy wound care, providing a promising new approach to improving the quality of skin recovery following radiotherapy.

Hydrogel Microneedle Patches Loaded with Stem Cell Mitochondria-Enriched Microvesicles Boost the Chronic Wound Healing

Rescuing or compensating mitochondrial function represents a promising therapeutic avenue for radiation-induced chronic wounds. Adult stem cell efficacies are primarily dependent on the paracrine secretion of mitochondria-containing extracellular vesicles (EVs). However, effective therapeutic strategies addressing the quantity of mitochondria and mitochondria-delivery system are lacking. Thus, in this study, we aimed to design an effective hydrogel microneedle patch (MNP) loaded with stem cell-derived mitochondria-rich EVs to gradually release and deliver mitochondria into the wound tissues and boost wound healing. We, first, used metformin to enhance mitochondrial biogenesis and thereby increasing the secretion of mitochondria-containing EVs (termed "Met-EVs") in adipose-derived stem cells. To verify the therapeutic effects of Met-EVs, we established an in vitro and an in vivo model of X-ray-induced mitochondrial dysfunction. The Met-EVs ameliorated the mitochondrial dysfunction by rescuing mitochondrial membrane potential, increasing adenosine 5'-triphosphate levels, and decreasing reactive oxygen species production by transferring active mitochondria. To sustain the release of EVs into damaged tissues, we constructed a Met-EVs@Decellularized Adipose Matrix (DAM)/Hyaluronic Acid Methacrylic Acid (HAMA)-MNP. Met-EVs@DAM/HAMA-MNP can load and gradually release Met-EVs and their contained mitochondria into wound tissues to alleviate mitochondrial dysfunction. Moreover, we found Met-EVs@DAM/HAMA-MNP can markedly promote macrophage polarization toward the M2 subtype with anti-inflammatory and regenerative functions, which can, in turn, enhance the healing process in mice with skin wounds combined radiation injuries. Collectively, we successfully fabricated a delivery system for EVs, Met-EVs@DAM/HAMA-MNP, to effectively deliver stem cell-derived mitochondria-rich EVs. The effectiveness of this system has been demonstrated, holding great potential for chronic wound treatments in clinic.

Hematoxylin and Eosin Architecture Uncovers Clinically Divergent Niches in Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) represents one of the only cancers with an increasing incidence rate and is often associated with intra- and peri-tumoral scarring, referred to as desmoplasia. This scarring is highly heterogeneous in extracellular matrix (ECM) architecture and plays complex roles in both tumor biology and clinical outcomes that are not yet fully understood. Using hematoxylin and eosin (H&E), a routine histological stain utilized in existing clinical workflows, we quantified ECM architecture in 85 patient samples to assess relationships between desmoplastic architecture and clinical outcomes such as survival time and disease recurrence. By utilizing unsupervised machine learning to summarize a latent space across 147 local (e.g., fiber length, solidity) and global (e.g., fiber branching, porosity) H&E-based features, we identified a continuum of histological architectures that were associated with differences in both survival and recurrence. Furthermore, we mapped H&E architectures to a CO-Detection by indEXing (CODEX) reference atlas, revealing localized cell- and protein-based niches associated with outcome-positive versus outcome-negative scarring in the tumor microenvironment. Overall, our study utilizes standard H&E staining to uncover clinically relevant associations between desmoplastic organization and PDAC outcomes, offering a translatable pipeline to support prognostic decision-making and a blueprint of spatial-biological factors for modeling by tissue engineering methods.

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

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

Glucopeptide Superstructure Hydrogel Promotes Surgical Wound Healing Following Neoadjuvant Radiotherapy by Producing NO and Anticellular Senescence

Neoadjuvant radiotherapy, a preoperative intervention regimen for reducing the stage of primary tumors and surgical margins, has gained increasing attention in the past decade. However, radiation-induced skin damage during neoadjuvant radiotherapy exacerbates surgical injury, remarkably increasing the risk of refractory wounds and compromising the therapeutic effects. Radiation impedes wound healing by increasing the production of reactive oxygen species and inducing cell apoptosis and senescence. Here, a self-assembling peptide (R-peptide) and hyaluronic-acid (HA)-based and cordycepin-loaded superstructure hydrogel is prepared for surgical incision healing after neoadjuvant radiotherapy. Results show that i) R-peptide coassembles with HA to form biomimetic fiber bundle microstructure, in which R-peptide drives the assembly of single fiber through π-π stacking and other forces and HA, as a single fiber adhesive, facilitates bunching through electrostatic interactions. ii) The biomimetic superstructure contributes to the adhesion and proliferation of cells in the surgical wound. iii) Aldehyde-modified HA provides dynamic covalent binding sites for cordycepin to achieve responsive release, inhibiting radiation-induced cellular senescence. iv) Arginine in the peptides provides antioxidant capacity and a substrate for the endogenous production of nitric oxide to promote wound healing and angiogenesis of surgical wounds after neoadjuvant radiotherapy.

Role of ferroptosis in radiation-induced soft tissue injury

Ionizing radiation has been pivotal in cancer therapy since its discovery. Despite its therapeutic benefits, IR causes significant acute and chronic complications due to DNA damage and the generation of reactive oxygen species, which harm nucleic acids, lipids, and proteins. While cancer cells are more vulnerable to ionizing radiation due to their inefficiency in repairing damage, healthy cells in the irradiated area also suffer. Various types of cell death occur, including apoptosis, necrosis, pyroptosis, autophagy-dependent cell death, immunogenic cell death, and ferroptosis. Ferroptosis, driven by iron-dependent lipid peroxide accumulation, has been recognized as crucial in radiation therapy's therapeutic effects and complications, with extensive research across various tissues. This review aims to summarize the pathways involved in radiation-related ferroptosis, findings in different organs, and drugs targeting ferroptosis to mitigate its harmful effects.

Single-cell transcriptional analysis of irradiated skin reveals changes in fibroblast subpopulations and variability in caveolin expression

BACKGROUND

Radiation-induced fibrosis (RIF) is an important late complication of radiation therapy, and the resulting damaging effects of RIF can significantly impact reconstructive outcomes. There is currently a paucity of effective treatment options available, likely due to the continuing knowledge gap surrounding the cellular mechanisms involved. In this study, detailed analyses of irradiated and non-irradiated human skin samples were performed incorporating histological and single-cell transcriptional analysis to identify novel features guiding development of skin fibrosis following radiation injury.

METHODS

Paired irradiated and contralateral non-irradiated skin samples were obtained from six female patients undergoing post-oncologic breast reconstruction. Skin samples underwent histological evaluation, immunohistochemistry, and biomechanical testing. Single-cell RNA sequencing was performed using the 10X single cell platform. Cells were separated into clusters using Seurat in R. The SingleR classifier was applied to ascribe cell type identities to each cluster. Differentially expressed genes characteristic to each cluster were then determined using non-parametric testing.

RESULTS

Comparing irradiated and non-irradiated skin, epidermal atrophy, dermal thickening, and evidence of thick, disorganized collagen deposition within the extracellular matrix of irradiated skin were readily appreciated on histology. These histologic features were associated with stiffness that was higher in irradiated skin. Single-cell RNA sequencing revealed six predominant cell types. Focusing on fibroblasts/stromal lineage cells, five distinct transcriptional clusters (Clusters 0-4) were identified. Interestingly, while all clusters were noted to express Cav1, Cluster 2 was the only one to also express Cav2. Immunohistochemistry demonstrated increased expression of Cav2 in irradiated skin, whereas Cav1 was more readily identified in non-irradiated skin, suggesting Cav1 and Cav2 may act antagonistically to modulate fibrotic cellular responses.

CONCLUSION

In response to radiation therapy, specific changes to fibroblast subpopulations and enhanced Cav2 expression may contribute to fibrosis. Altogether, this study introduces a novel pathway of caveolin involvement which may contribute to fibrotic development following radiation injury.

Deferoxamine Intradermal Delivery Patch for Treatment of a Radiation Therapy Associated Breast Wound

Purpose

Radiation therapy is used in over 60% of cancer patients and can lead to radiation dermatitis, radiation induced fibrosis, hyperpigmentation, telangiectasias, fat necrosis, and poor wound healing. Deferoxamine (DFO) is an iron-chelating agent that has been used systemically to treat iron overload conditions and more recently been studied to treat radiation fibrosis. Through iron chelation, DFO stabilizes hypoxia inducible factor-1α, driving downstream upregulation of angiogenic factors, and reduces formation of reactive oxygen species, thereby offering a potential therapy for radiation associated chronic wounds. The purpose of this work was to describe treatment of a refractory wound following radiation treatment that had failed conventional therapy.

Methods

The patient is a 71-year-old female with inflammatory breast cancer that developed a radiation related wound after mastectomy, chemotherapy, and radiation therapy. The wound did not show any signs of improvement with five months of wound care and risk factor modification. The patient was offered treatment with a topical Deferoxamine Intradermal Delivery Patch through the FDA single patient investigative new drug pathway.

Results

After two weeks of treatment, the wound healed. Additionally, serum was collected at cessation of therapy and 5 weeks after, with both samples showing no significant systemically detectible level of the drug to be present. Subjectively the patient reported improvement in appearance and quality of the skin.

Conclusion

Topical deferoxamine is a promising therapy for radiation wounds. Although this report is limited to a single patient experience, we believe this work is important in describing the first in-human use of topical deferoxamine to heal a radiation therapy associated wound.

Adipose-Derived Stromal Cell-Based Therapies for Radiation-Induced Fibrosis

Significance: Half of all cancer patients receive radiation therapy as a component of their treatment regimen, and the most common resulting complication is radiation-induced fibrosis (RIF) of the skin and soft tissue. This thickening of the dermis paired with decreased vascularity results in functional limitations and esthetic concerns and poses unique challenges when considering surgical exploration or reconstruction. Existing therapeutic options for RIF of the skin are limited both in scope and efficacy. Cell-based therapies have emerged as a promising means of utilizing regenerative cell populations to improve both functional and esthetic outcomes, and even as prophylaxis for RIF. Recent Advances: As one of the leading areas of cell-based therapy research, adipose-derived stromal cells (ADSCs) demonstrate significant therapeutic potential in the treatment of RIF. The introduction of the ADSC-augmented fat graft has shown clinical utility. Recent research dedicated to characterizing specific ADSC subpopulations points toward further granularity in understanding of the mechanisms driving the well-established clinical outcomes seen with fat grafting therapy. Critical Issues: Various animal models of RIF demonstrated improved clinical outcomes following treatment with cell-based therapies, but the cellular and molecular basis underlying these effects remains poorly understood. Future Directions: Recent literature has focused on improving the efficacy of cell-based therapies, most notably through (1) augmentation of fat grafts with platelet-rich plasma and (2) the modification of expressed RNA through epitranscriptomics. For the latter, new and promising gene targets continue to be identified which have the potential to reverse the effects of fibrosis by increasing angiogenesis, decreasing inflammation, and promoting adipogenesis.

Deferoxamine topical cream superior to patch in rescuing radiation-induced fibrosis of unwounded and wounded skin

Topical patch delivery of deferoxamine (DFO) has been studied as a treatment for this fibrotic transformation in irradiated tissue. Efficacy of a novel cream formulation of DFO was studied as a RIF therapeutic in unwounded and excisionally wounded irradiated skin. C57BL/6J mice underwent 30 Gy of radiation to the dorsum followed by 4 weeks of recovery. In a first experiment, mice were separated into six conditions: DFO 50 mg cream (D50), DFO 100 mg cream (D100), soluble DFO injections (DI), DFO 1 mg patch (DP), control cream (Vehicle), and irradiated untreated skin (IR). In a second experiment, excisional wounds were created on the irradiated dorsum of mice and then divided into four treatment groups: DFO 100 mg Cream (W-D100), DFO 1 mg patch (W-DP), control cream (W-Vehicle), and irradiated untreated wounds (W-IR). Laser Doppler perfusion scans, biomechanical testing, and histological analysis were performed. In irradiated skin, D100 improved perfusion compared to D50 or DP. Both D100 and DP enhanced dermal characteristics, including thickness, collagen density and 8-isoprostane staining compared to untreated irradiated skin. D100 outperformed DP in CD31 staining, indicating higher vascular density. Extracellular matrix features of D100 and DP resembled normal skin more closely than DI or control. In radiated excisional wounds, D100 facilitated faster wound healing and increased perfusion compared to DP. The 100 mg DFO cream formulation rescued RIF of unwounded irradiated skin and improved excisional wound healing in murine skin relative to patch delivery of DFO.

Understanding wound healing in obesity

Obesity has become more prevalent in the global population. It is associated with the development of several diseases including diabetes mellitus, coronary heart disease, and metabolic syndrome. There are a multitude of factors impacted by obesity that may contribute to poor wound healing outcomes. With millions worldwide classified as obese, it is imperative to understand wound healing in these patients. Despite advances in the understanding of wound healing in both healthy and diabetic populations, much is unknown about wound healing in obese patients. This review examines the impact of obesity on wound healing and several animal models that may be used to broaden our understanding in this area. As a growing portion of the population identifies as obese, understanding the underlying mechanisms and how to overcome poor wound healing is of the utmost importance.

YAP promotes the healing of ischemic wounds by reducing ferroptosis in skin fibroblasts through inhibition of ferritinophagy

The impaired healing of chronic wounds is often attributed to the ischemic and hypoxic microenvironment, leading to increased cell death. Ferroptosis, a novel form of cell death unveiled in recent years, could potentially be linked with the process of wound healing. In this study, we explored the significance and mechanism of ferroptosis in ischemic wounds. Using transmission electron microscopy, Western blot, flow cytometry, immunofluorescence, and glutathione (GSH) assay, we observed that the death of primary mouse skin fibroblasts induced by oxygen and glucose deprivation (OGD) was associated with ferroptosis. Specifically, we observed elevated intracellular Fe2+ and lipid peroxidation levels and decreased GSH levels in vitro, indicative of ferroptosis. Importantly, we found that ferroptosis in OGD-treated skin fibroblasts was dependent on autophagy, as the autophagy inhibitor chloroquine phosphate (CHQ) significantly reduced ferroptosis induced by OGD. Moreover, our study revealed that NCOA4-mediated ferritinophagy significantly contributed to the occurrence of ferroptosis induced by OGD in skin fibroblasts. Additionally, we identified the involvement of YAP in the regulation of ferritinophagy, with YAP suppressing NCOA4 expression in OGD-treated skin fibroblasts, thereby reducing ferroptosis. Furthermore, in ischemic wound models in mice, both inhibitors of ferroptosis and autophagy promoted wound healing, while a YAP inhibitor, verteporfin, delayed wound healing. In conclusion, these findings indicate that ferroptosis, regulated by YAP through ferritinophagy inhibition, presents a novel mechanism responsible for the delayed healing of ischemic wounds. Understanding this process could offer promising therapeutic targets to improve wound healing in ischemic conditions.

A temperature and pH dual-responsive injectable self-healing hydrogel prepared by chitosan oligosaccharide and aldehyde hyaluronic acid for promoting diabetic foot ulcer healing

Chronic wound, such as skin defect after burn, pressure ulcer, and diabetic foot ulcer is very difficult to cure. Its pathological process is often accompanied with local temperature rise, pH decrease, and other phenomena. Owing to their outstanding hydrophilic, biocompatibility, and responsive properties, hydrogels could accelerate the healing process. In this study, we chose chitosan oligosaccharide (COS) grafted with Pluronic F127 (F127-COS). Aldehyde hyaluronic acid (A-HA) oxidized by NaIO4. And added boric acid (BA) to prepare a thermosensitive and pH-responsive injectable self-healing F127-COS/A-HA/COS/BA (FCAB) hydrogel, loaded with drug deferoxamine (DFO) in order to have an accurate release and promote angiogenesis of diabetic foot ulcer. In vitro experiments had verified that the FCAB hydrogel system loaded with DFO (FCAB/D) could promote migration and angiogenesis of HUVEC. A diabetes rat back wound model further confirmed its role in promoting angiogenesis in wound repair process. The results showed that the FCAB/D hydrogel exhibited unique physicochemical properties, excellent biocompatibility, and significantly enhanced therapeutic effects for diabetic foot ulcer.

Topical Iron Chelator Therapy: Current Status and Future Prospects

Systemic iron chelation therapy has long been used for iron overload, providing a role in returning iron levels to proper homeostatic concentrations. Recently, topical iron chelation therapy has emerged as a potential strategy for treating skin damage. This narrative review explores the current status and future prospects of topical iron chelation therapy for treating ultraviolet (UV) and non-UV skin damage, as well as its potential application in wound healing. The review was conducted through a literature search across PubMed, Web of Science, and EMBASE databases, spanning publications from 1990 to 2023. The selection of articles was focused on primary research studies, either experimental or clinical, that explored the implications and formulations of topical iron chelators used alone or in conjunction with another therapeutic agent. The search strategy employed a combination of terms, including "topical iron chelation", "topical deferoxamine", "UV", "wound healing", "skin inflammation", "radiation-induced fibrosis", and "skin cancer". Relevant studies, including methods, intervention strategies, measured outcomes, and findings, are summarized. The review also considered the potential challenges in translating research findings into clinical practice. Results indicate that topical iron chelators, such as deferoxamine, are effective in mitigating UV-induced skin damage, reducing tumorigenesis, and decreasing oxidative damage. In addition, the use of these agents in radiation-induced fibrosis has been shown to significantly increase skin elasticity and reduce dermal fibrosis. Several studies also highlight the use of topical iron chelators in difficult-to-treat chronic wounds, such as diabetic neuropathic ulcers and sickle cell ulcers. In conclusion, topical iron chelation therapy represents a novel and promising approach for skin protection and wound healing. Its potential makes it a promising area of future research.

The Potential of MSC-Based Cell-Free Therapy in Wound Healing-A Thorough Literature Review

A wound is an interruption of the normal anatomic structure and function of the skin, which is critical in protecting against foreign pathogens, regulating body temperature and water balance. Wound healing is a complex process involving various phases, including coagulation, inflammation, angiogenesis, re-epithelialization, and re-modeling. Factors such as infection, ischemia, and chronic diseases such as diabetes can compromise wound healing, leading to chronic and refractory ulcers. Mesenchymal stem cells (MSCs) have been used to treat various wound models due to their paracrine activity (secretome) and extracellular vehicles (exosomes) that contain several molecules, including long non-coding RNAs (lncRNAs), micro-RNAs (miRNAs), proteins, and lipids. Studies have shown that MSCs-based cell-free therapy using secretome and exosomes has great potential in regenerative medicine compared to MSCs, as there are fewer safety concerns. This review provides an overview of the pathophysiology of cutaneous wounds and the potential of MSCs-based cell-free therapy in each phase of wound healing. It also discusses clinical studies of MSCs-based cell-free therapies.

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.

Chelating the valley of death: Deferoxamine's path from bench to wound clinic

There is undisputable benefit in translating basic science research concretely into clinical practice, and yet, the vast majority of therapies and treatments fail to achieve approval. The rift between basic research and approved treatment continues to grow, and in cases where a drug is granted approval, the average time from initiation of human trials to regulatory marketing authorization spans almost a decade. Albeit with these hurdles, recent research with deferoxamine (DFO) bodes significant promise as a potential treatment for chronic, radiation-induced soft tissue injury. DFO was originally approved by the Food and Drug Administration (FDA) in 1968 for the treatment of iron overload. However, investigators more recently have posited that its angiogenic and antioxidant properties could be beneficial in treating the hypovascular and reactive-oxygen species-rich tissues seen in chronic wounds and radiation-induced fibrosis (RIF). Small animal experiments of various chronic wound and RIF models confirmed that treatment with DFO improved blood flow and collagen ultrastructure. With a well-established safety profile, and now a strong foundation of basic scientific research that supports its potential use in chronic wounds and RIF, we believe that the next steps required for DFO to achieve FDA marketing approval will include large animal studies and, if those prove successful, human clinical trials. Though these milestones remain, the extensive research thus far leaves hope for DFO to bridge the gap between bench and wound clinic in the near future.

Recent advances of the nanocomposite hydrogel as a local drug delivery for diabetic ulcers

Diabetic ulcer is a serious complication of diabetes. Compared with that of healthy people, the skin of patients with a diabetic ulcer is more easily damaged and difficult to heal. Without early intervention, the disease will become increasingly serious, often leading to amputation or even death. Most current treatment methods cannot achieve a good wound healing effect. Numerous studies have shown that a nanocomposite hydrogel serves as an ideal drug delivery method to promote the healing of a diabetic ulcer because of its better drug loading capacity and stability. Nanocomposite hydrogels can be loaded with one or more drugs for application to chronic ulcer wounds to promote rapid wound healing. Therefore, this paper reviews the latest progress of delivery systems based on nanocomposite hydrogels in promoting diabetic ulcer healing. Through a review of the recent literature, we put forward the shortcomings and improvement strategies of nanocomposite hydrogels in the treatment of diabetic ulcers.