Wound Model Research Articles

Growth factors IGF-1 and KGF and adipose-derived stem cells promote migration and viability of primary human keratinocytes in an in vitro wound model

IntroductionIn the field of plastic surgery, epidermal transplantation is a potential treatment for chronic wounds that results in only minor donor site morbidity. Improving the regenerative capacities of epidermal grafts or single-cell suspensions and therefore accelerating healing processes would be of significant interest.MethodsIn the present study, we analyzed the effects of growth factors and adipose-derived stem cells (ADSCs) on keratinocyte properties. For optimum translation into the clinical setting, primary human keratinocytes and patient-matched ADSCs were isolated and used in an in vitro wound model.ResultsThe keratinocyte migration and viability increased after treatment with the growth factors insulin-like growth factor 1 (IGF-1) and keratinocyte growth factor (KGF). A similar effect was observed with the use of a concentrated ADSC-conditioned medium (ADSC-CM). It was further possible to isolate the keratinocytes in a xenogen-free medium, which is essential for clinical translation. Importantly, a patient-dependent influence on the effects of the growth factors and ADSC-CM was observed.DiscussionThis study provides potential for the improvement of epidermal transplantation in the treatment of chronic wounds using xenogen-free isolated and cultivated keratinocytes, growth factors, and ADSC. Translating these results into clinical application may help accelerate wound healing and shorten the time until patients can return to everyday life.

Peptide Double-Stapling and Arginine N-Glycosylation Triggered the Development of Therapeutic Antimicrobial Peptides Capable of Killing Drug-Resistant Bacteria in Mice.

Antimicrobial peptides SAAP-148 exhibited excellent antimicrobial activities but suffered from inherent disadvantages, including cytotoxicity and poor proteolytic stability. Herein, we developed a novel strategy combining one unique silver-catalyzed solid-phase glycosylation-enabled arginine N-glycosylation strategy and all-hydrocarbon peptide double-stapling, and five-round peptide libraries were rationally constructed containing over 50 stapled and/or arginine N-glycosylated peptides. SLP-51 consisting of two introduced all-hydrocarbon staples and the C-terminal arginine glycosylation exhibited superior in vitro antimicrobial activities against drug-resistant Gram-positive or -negative clinical isolates. SLP-51 also exhibited improved proteolytic stability than the parent peptide SLP-0, and importantly, significantly weakened hemolysis. Experimental and modeling mechanism research indicated that SLP-51 exerted similar but stronger killing abilities by destroying the integrality of the bacterial membranes. In both skin wound and drug-resistant bacterial pneumonia models, SLP-51 showcased a potent therapeutic effect in treating both MRSA and Klebsiella pneumoniae infection in vivo and dramatical improvement of inflammatory injury.

The Effect of Agave Bagasse Extract on Wound Healing in a Murine Model

Background/Objectives: The development of bioproducts that can accelerate wound healing is a key focus in biomedicine, especially when these products are derived from sustainable by-products. This study investigates the wound-healing potential of an extract obtained from Agave angustifolia Haw bagasse (BagEE) using microwave extraction.Methods: HPLC-MS analysis was performed to identify the main compounds present in BagEE, revealing quercetin, isorhamnetin, diosgenin, hecogenin, manogenin, β-sitosterol glucoside, and β-sitosterol as tentative constituents. A murine excision wound model was employed to assess the efficacy of BagEE. The experimental group received a topical application of 8 mg of BagEE, while the control group was treated with water only. Wound closure, re-epithelialization, and collagen deposition were evaluated to determine the effects of BagEE on skin healing. Results: The BagEE-treated group exhibited significantly accelerated wound healing, achieving a 99.4% closure rate by day 13 compared to the control group’s 92.8% closure rate on day 22. Additionally, wounds treated with BagEE displayed complete re-epithelialization and a well-organized skin structure. Conclusions: These findings suggest that BagEE promotes effective wound healing and shows promise as a topical agent for skin regeneration. Further studies are necessary to investigate its anti-inflammatory and wound-healing activities in both in vivo and in vitro settings.

Efficiency of medical leech on experimentally induced incisional wound healing in rats.

This study was conducted in response to the increasing interest in understanding the effects of both modern and traditional complementary medicine on incisional wound healing. Herein, it was aimed to investigate the wound healing effects of medicinal leech therapy and leech saliva in an experimentally created incisional skin wound model. Fifteen rats underwent full-thickness incisions on their dorsal regions and were randomly assigned to five equal groups, as the Leech Saliva (LS) group, where wounds were treated topically with leech saliva once daily; Leech Therapy-1 (LT-1) group, where leech therapy was administered once at the beginning of the experiment; Leech Therapy-2 (LT-2) group, where leech therapy was applied twice, on days 0 and 3; Positive Control (PC) group, where wounds were treated daily with Phyto cream containing Triticum vulgare; and Negative Control (NC) group, where no treatment was given. Wound healing was assessed daily, and the experiment continued until complete healing was observed. At the conclusion, the wound size, appearance, and histological features were analyzed to compare healing progress across the groups. Medicinal leech therapy was observed to have a positive wound healing effect in the rat model.

A Cutting-Edge Multilayer Nanofiber Wound Dressing: Design, Synthesis, and Investigation for Enhanced Wound Healing InVitro and InVivo.

Wounds, disruptions in normal anatomy, are classified as acute or chronic. The choice of wound treatment relies significantly on dressing materials. Electrospun nanofibrous materials offer promising applications in wound healing, featuring a substantial surface area, close mimicry of the natural extracellular matrix, and adjustable water resistance, air permeability, and drug release. This research endeavors to formulate an innovative three-layered nanofibrous wound dressing using the electrospinning technique with the primary objectives of enhancing patient well-being, exhibiting antimicrobial characteristics, and expediting wound healing. The designed dressing comprises nanofibers of polyurethane (PU), quercetin (Q)-loaded polyethylene glycol (PEG), polyvinyl alcohol (PVA), and gelatin. Characterization of individual layers and the integrated wound dressing was conducted through SEM and FT-IR analyses. The efficacy of the nanofibrous wound dressing was assessed through invitro human cell culture and invivo rat wound models. The anti-toxic effects of nanofiber wound dressing on human epithelial and keratin cells have been proven. Invitro wound models in 24-well plates were utilized to assess the impact on wound healing rates. Photographic documentation of wound closure was performed at the different treatment hours, revealing complete closure of the wounds by the end of the 48th hour. Rats with 2 × 1 cm wounds were treated with the nanofibrous dressings, and wound healing progress was observed over a 14-day period. qRT-PCR was employed to analyze MMP-9, TIMP1, COL1A1, PDGFA, and VEGFC mRNA expressions. With its contemporary design surpassing existing treatments, the nanofiber wound dressing stands out for its wound-healing acceleration and antibacterial properties.

Evaluation of wound healing activity of the crude extract and solvent fractions of Rumex nervosus Vahl (Polygonaceae) leaves in mice.

In Ethiopian traditional medicine, Rumex nervosus Vahl leaves are used to treat wounds. However, despite traditional claims and supportive in vitro findings, no scientific study has been conducted to evaluate the in vivo wound healing activity of R. nervosus Vahl leaves. To evaluate the wound healing activity of crude extract of the leaves of R. nervosus Vahl and its solvent fractions in mice. R. nervosus Vahl leaves were extracted with 80% methanol, and then the crude extract was fractionated using ethyl acetate, chloroform, and water. Ointments at 5% and 10% strengths were formulated from the crude extract and its fractions. The healing activity of the crude extract was evaluated using linear incision, circular excision, and burn wound models in mice. Additionally, the activity of solvent fractions was assessed using circular excision wounds in mice. Treatment of wounds with ointments containing 5% and 10% crude extract showed significantly increased wound contraction rate, shorter epithelialization period, and higher skin-breaking strength (P < 0.05) compared with the negative control. Both 5% and 10% formulations of the aqueous and ethyl acetate fractions significantly increased wound contraction and decreased the period of epithelialization in the excision wound model (p < 0.05), however, the chloroform fraction showed no significant wound healing effect compared with the negative control. The 80% methanol crude extract as well as the aqueous and ethyl acetate fractions of R. nervosus Vahl leaves possess wound healing activity as evidenced by improved wound contraction rate and tensile strength and decreased epithelialization period.

Lauric acid-mediated gelatin/hyaluronic acid composite hydrogel with effective antibacterial and immune regulation for accelerating MRSA-infected diabetic wound healing.

The infected diabetic wound healing is an increasingly severe healthcare problem worldwide. Bacterial infection and the inflammatory microenvironment hinder diabetic wound healing. Meanwhile, the combination of inhibiting bacterial growth and promoting macrophage polarization in the wound microenvironment is beneficial for treating diabetic wounds. Nowadays, hydrogels, as an emerging wound dressing, have great potential to replace or supplement traditional bandages or gauze. Here, glycyl methacrylate gelatin (Gel-Gym), oxidized hyaluronic acid (HA-CHO) and lauric acid (LA) were used to prepare the composite hydrogel (GH/LA) in addressing the clinical dilemma. The hydrogel could withstand 50% compression deformation, its swelling rate was as low as 18%, and its adhesion to pig skin reached 14kPa. Moreover, a diabetic infected wound model was used to evaluate the feasibility of GH/LA hydrogel in vivo. The hydrogels' antimicrobial, anti-inflammatory and prorestitutive potentials were further investigated, and GH/LA showed a therapeutic effect on diabetic wounds. Interestingly, macrophage polarization into the M2 phenotype was significantly enhanced in the presence of GH/LA via GPR40/NF-κB pathway. This study provided a new avenue for treating methicillin-resistant staphylococcus aureus (MRSA) infected diabetic wounds.

Rat model evaluation for healing-promoting effectiveness and antimicrobial activity of electron beam synthesized (polyvinyl alcohol-pectin)- silver doped zinc oxide hydrogel dressings enriched with lavender oil.

Ag/ZnO NPs and lavender oil (LVO) were incorporated into (polyvinyl alcohol/pectin) (PVA/Pet) dressings using electron beam irradiation technology. The Ag/ZnO NPs were prepared using the precipitation method and characterized using XRD, FTIR, and EDX techniques. TEM micrograph shows their spherical appearance with an average size of around 27.4nm. The increase in the (PVA: Pet) feed solution concentration up to 30% enhances the gel content to 92%. The swelling degree reaches 1674% using 80wt% pectin content. Meanwhile, increasing the irradiation dose up to 45kGy increases the gel fraction and negatively affects the swelling capabilities. Incorporating Ag/ZnO NPs and LVO slightly decreased the gel fraction, the swelling degree, and the dressing's porosity reached 87%. In pseudo extracellular fluids, dressings with 10% LVO demonstrate 419% swelling capacities, and their WVTR reaches 271.1g/m2h. Dressings show biocompatibility, antimicrobial potential, and excellent wound healing capacity towards the excisional wound model in rats, as confirmed by the histological and biochemical results. LVO-(PVA/Pet)-Ag/ZnO dressings may accelerate tissue granulation and remodeling by replacing lost collagen and cause the wound to constrict by upregulating markers associated with wound healing so that it can be recommended as a wound healing candidate.

Delayed Immune Response Upon Injury in Diabetic Wounds Impedes Healing.

Chronic wounds are a severe complication of diabetes. Dysregulated inflammatory signalling is thought to underly the poor healing outcomes. Yet, there is little information available on the acute response following injury and its impact on healing. Using a murine full thickness excisional wound model, the current study therefore assessed the expression of pro-inflammatory and pro-resolving lipid mediators during the early stages post injury in acute and diabetic wounds and compared the timeframe for transitioning through the phases of healing. Tissue eicosanoid (LTB4, PGE2, TxA2, MaR1, RvE1, RvD1, PD) and MMP-9 levels were assessed at 6 h post wounding using ELISAs. Wound closure, healing dynamics (histology), cellular infiltration and MPO, TNF-α expression (IHC) were assessed at 6 h, day2, day7 post wounding. Eicosanoid expression did not differ between groups (LTB4 24-125 pg/mL, PGE2 63-177 pg/mL, TxA2 529-1184 pg/mL, MaR1 365-2052 pg/mL, RvE1 43-1157 pg/mL, RvD1 1.5-69 pg/mL, PD1 11.5-4.9 ng/mL). An inverse relationship (p < 0.05) between MMP-9 and eicosanoids were however only evident in acute and not in diabetic wounds. Diminished cellular infiltration (x5 fold) (p < 0.05) in diabetic wounds coincided with a significant delay in the expression of TNF-α (pro-inflammatory cytokine) and MPO (neutrophil marker). A significant difference in the expression of TNF-α (C 1.8 ± 0.6; DM 0.7 ± 0.1 MFI) and MPO (C 4.9 ± 1.9; DM 0.9 ± 0.4 MFI) (p < 0.05) was observed as early as 6 h post wounding, with histology parameters supporting the notion that the onset of the acute inflammatory response is delayed in diabetic wounds. These observations imply that the immune cells are unresponsive to the initial eicosanoid expression in the diabetic wound tissue.

A multi-functional oxidative konjac glucomannan/ε-poly-l-lysine hydrogel with antibacterial, haemostatic, and chronic diabetic wound-treating properties.

A chronic diabetic wound, one of the most severe complications of diabetes, has a high incidence and causes great pain to patients, threatening their lives. In this paper, oxidative konjac glucomannan (OKGM) was reacted with ε-poly-l-lysine (EPL) through the dynamic Schiff's base reaction to make a multi-functional hydrogel. This hydrogel had excellent mechanical properties, injectability, self-healing ability, adhesivity and cytocompatibility. The outstanding haemostatic property was also expressed in rat liver incision, liver injury and tail truncation models. In addition, this hydrogel exhibited unique antibacterial ability against the Gram-positive Staphylococcus aureus (S. aureus), the Gram-negative Escherichia coli (E. coli) and the Gram-negative Pseudomonas aeruginosa (P. aeruginosa). It also promoted wound healing, enhanced angiogenesis and regulated macrophage polarisation in the whole-layer rat diabetic wound model. The multi-functional hydrogel is a dressing with huge potential and prospects in chronic diabetic wound healing.

Wound-Healing Activity of Solvent Fractions and Antiinflammatory Activity of Crude Extract and Solvent Fractions of Acokanthera schimperi Schweinf (Apocynaceae) Leaves in Mice Model

BackgroundIn Ethiopia, Acokanthera schimperi is frequently used to treat wounds and other conditions. Nothing has been published to date on the anti-inflammatory properties of A. schimperi leaves or the wound-healing effects of solvent fractions, despite a report on the crude extract's ability to heal wounds being available in the literature. PurposeTherefore, this experiment has been initiated to look into the solvent fractions' ability to heal wounds and the anti-inflammatory properties of the A. schimperi leaf 80% methanol extract and its fractions in mice. Study designThe experimental study design was conducted to evaluate wound healing and the anti-inflammatory properties of the A. schimperi leaf 80% methanol extract and its fractions in mice. MethodsThe plant's leaf crude extract was fractionated using ethyl acetate, chloroform, and distilled water. The resulting fractions were then combined with a simple ointment base to make an ointment at 5% and 10% w/w. Next, using excision and incision wound models, the ointments' ability to promote wound healing was assessed. The excision model was utilised to estimate wound contraction and epithelization time, whereas the incision model was utilised to measure tensile strength. By dissolving 1% carrageenan in 0.9% saline (w/v) and giving oral dosages of the crude extract and solvent fractions (100, 200, and 400 mg/kg), the anti-inflammatory efficacy of the leaves was assessed concurrently with a carrageenan-induced hind paw edema model. ResultsSignificant wound healing activity was seen in both models in wounds treated with 5% and 10% (w/w) solvent fraction ointment, as shown by higher tissue breaking strength (with 51.38% maximum effect by 10% (w/w) ethyl acetate fraction ointment), shorter epithelization times (within 15.92 days by ethyl acetate fraction ointment 10%), and increased wound contraction (99.40% by ethyl acetate fraction ointment 10%). The extract (hydromethanolic) and solvent fractions also showed notable dose-related decreases in inflammation. ConclusionThe study's findings supported A. schimperi's traditional use as a wound healing agent by showing that the solvent fractions of the plant's leaves promoted wound healing, at least in part, through their anti-inflammatory effect.

The immunoglobulin of yolk and cerium oxide-based fibrous poly(L-lactide-co-glycolide)/gelatin dressings enable skin regeneration in an infectious wound model

The immunoglobulin of yolk and cerium oxide-based fibrous poly(L-lactide-co-glycolide)/gelatin dressings enable skin regeneration in an infectious wound model

A dual-modified glucomannan polysaccharide selectively sequesters growth factors for skin tissue repair.

Artificial dermal matrixes (ADMs) are valuable clinical options for treating large soft tissue defects, but their suboptimal bioactivities compared with the real tissue limit their therapeutic potential. For example, glycosaminoglycan (GAG) polysaccharides in the native skin vitally and differentially regulate endogenous growth factors (GFs) to maintain tissue homeostasis. However, the GAG used in the current ADMs has often lost such delicate regulation. Here, we developed a novel polysaccharide-based ADM that can promote skin tissue repair through selective modulation of specific pro-healing GFs. First, we prepared a plant-derived backbone of glucomannan (named BSP) - representing the two dominant monosaccharide components in the human body - in mass and homogenic quality. Then, we modified this backbone with sulfate and acetyl groups in a controlled manner to yield an optimized BSP derivative (SMAL-BSP) as a main composition to generate a new ADM. In vitro, SMAL-BSP enabled the ADM to selectively sequester pro-angiogenic GFs of VEGF-A and FGF-2 in situ for stimulating endothelial cell growth. Moreover, the addition of the acetyl group induced macrophages to secrete nitric oxide (NO) with antibacterial activities. Further in vivo tests in a rat model of full-thickness skin wounds indicated that SMAL-BSP ADM could sequester GFs in situ to promote angiogenesis and thus tissue regeneration, with superior effects than conventional chondroitin sulfate-based ADM, while showing no adverse effects often associated with animal-derived products. Our study represents a novel strategy for ADM design, targeting selective GF sequestration towards optimal skin tissue regeneration.

Evaluation of anti-inflammatory and wound healing properties of Tinospora cordifolia extract.

Tinospora cordifolia extract exhibits diverse benefits-anti-arthritis, anti-malarial, anti-allergic, anti-diabetic, antihepatotoxic, and antipyretic effects. Its specific anti-inflammatory and healing capacities remain unexplored, prompting a study utilizing a mouse skin wound model and direct T. cordifolia extraction. UV-Vis spectroscopy depicted an absorption range of 200-400 nm, while FTIR analysis identified alcohols, phenols, amines, amides, aldehydes, ketones, alkanes, and alkenes. GC-MS analysis revealed the presence of components: 5methyl-5-Hexen-2-Ol, n-hexadecenoic acid, cholesta-4,6-dien-3beta-ol, stigmasterol, β-sitosterol, stearate which are present in the extract. Histopathological examination confirmed accelerated wound healing, showcasing reduced inflammation, restored blood vessels, collagen fibers, and swift epidermal closure. T. cordifolia extract exhibits promise in enhancing wound healing through its antibacterial, anti-inflammatory properties.

Carboxy-Amidated AamAP1-Lys has Superior Conformational Flexibility and Accelerated Killing of Gram-Negative Bacteria.

C-terminal amidation of antimicrobial peptides (AMPs) is a frequent minor modification used to improve antibacterial potency, commonly ascribed to increased positive charge, protection from proteases, and a stabilized secondary structure. Although the activity of AMPs is primarily associated with the ability to penetrate bacterial membranes, hitherto the effect of amidation on this interaction has not been understood in detail. Here, we show that amidation of the scorpion-derived membranolytic peptide AamAP1-Lys produces a potent analog with faster bactericidal activity, increased membrane permeabilization, and greater Gram-negative membrane penetration associated with greater conformational flexibility. AamAP1-lys-NH2 has improved antibiofilm activity against Acinetobacter baumannii and Escherichia coli, benefits from a two- to 3-fold selectivity improvement, and provides protection against A. baumannii infection in a Galleria mellonella burn wound model. Circular dichroism spectroscopy shows both peptides adopt α-helix conformations in the steady state. However, molecular dynamics (MD) simulations reveal that, during initial binding, AamAP1-Lys-NH2 has greater conformation heterogeneity, with substantial polyproline-II conformation detected alongside α-helix, and penetrates the bilayer more readily than AamAP1-Lys. AamAP1-Lys-NH2 induced membrane permeabilization of A. baumannii occurs only above a critical concentration with slow and weak permeabilization and slow killing occurring at its lower MIC but causes greater and faster permeabilization than AamAP1-Lys, and kills more rapidly, when applied at equal concentrations. Therefore, while the increased potency of AamAP1-Lys-NH2 is associated with slow bactericidal killing, amidation, and the conformational flexibility it induces, affords an improvement in the AMP pharmacodynamic profile and may need to be considered to achieve improved therapeutic performance.

In Situ-Forming, Adhesive, and Antioxidant Chitosan Hydrogels for Accelerated Wound Healing.

Antioxidant hydrogels that can provide a moist environment and scavenge reactive oxygen species have emerged as highly potential wound dressing materials. In situ-forming and good tissue adhesiveness will make them more desirable, as they can fill the irregular wound defect, stick to the wound, and offer intimate contact with the wound. Herein, a hydrogel dressing combining in situ-forming, good tissue adhesiveness, and excellent antioxidant capabilities was developed by simply conjugating dopamine onto carboxymethyl chitosan. The introduction of dopamine allows in situ gelation of the polymer under mild conditions using an HRP-catalyzed cross-linking reaction. The introduction of dopamine also endows the hydrogels with suitable tissue-adhesion properties. Excellent antioxidant properties were also imparted as a result of the introduction of dopamine. Thanks to the favorable moist environment provided by the hydrogel and the effectively mitigated oxidative stress at wound sites, accelerated healing and reduced scar formation were observed in a rat full-thickness skin wound model.

Beyond the Case Study: Laboratory Activities to Complement Integumentary Education.

To present a full scope of detailed and engaging laboratory activities recommended by physical therapist clinicians and educators from across the US to assist health professions faculty to develop new or improve current integumentary/wound management (IWM) instruction. A three-round Delphi survey was conducted to update IWM curriculum recommendations for entry-level doctor of physical therapy education. First-round participants provided ideas for laboratory activities. Activity responses were discussed, edited for redundancy, and clarified. Missing information (eg, estimated cost and time required) was added to increase usability. A total of 139 laboratory activities were recommended by survey participants. Many of the suggestions included inexpensive and readily available, do-it-yourself wound models requiring food or other moulage techniques. These simulations are elucidated to facilitate translation of ideas into classroom and community laboratory activities to promote student learning. The literature supports that most entry-level healthcare profession programs report limited IWM education, emphasizing the need for effective and efficient use of IWM contact hours. Developing engaging and meaningful hands-on laboratory activities is vital to increasing student knowledge and skill in this area of clinical practice.

Multi‐Functional Responsive Microcapsules with Sequential Release Capacity for Wound Healing

AbstractThe development of biomaterials capable of on‐demand delivery holds significant promise for wound therapy. Current research is centered on refining design precision and enhancing structural functionality to achieve effective controlled release of active agents, thereby facilitating wound healing. In this study, a coaxial microfluidic electrospray technique is employed to fabricate microcapsules comprising a black phosphorus (BP)‐laden alginate shell and a gelatin methacrylate (GelMA) core. Curcumin nanoparticles (CNPs) and vascular endothelial growth factor (VEGF) are respectively incorporated into the shell and core of the microcapsules. The photothermal performance of the microcapsules contributed to superior sterilization efficacy in the early stages of wound healing, while the growth factors in the core provided robust angiogenic effects during the later stages. These attributes enabled the microcapsules to significantly accelerate wound healing, enhance collagen deposition, and modulate inflammatory responses in a rat wound model, underscoring their potential for clinical application.

Bioactive Hydrogel Supplemented with Stromal Cell-Derived Extracellular Vesicles Enhance Wound Healing

Background/Objectives: Skin regeneration is a rapidly advancing field with significant implications for regenerative medicine, particularly in treating wounds and burns. This study explores the potential of hydrogels functionalized with fibroblast-derived extracellular vesicles (EVs) to enhance skin regeneration in vivo. Being immunoprivileged, EVs minimize immune rejection, offering an attractive alternative to whole-cell therapies by replicating fibroblasts’ key roles in tissue repair. Methods: To promote EVs’ versatility and effective application across different conditions, a lyophilization method with lyoprotectants was optimized. Then, EVs were used to functionalize a hydrogel to perform experiments on murine cutaneous wound models. Results: Gelatin methacrylate (GelMA) was selected as the polymeric hydrogel due to its biocompatibility, tunable mechanical properties, and ability to support wound healing. Mechanical tests confirmed GelMA’s strength and elasticity for this application. Fibroblast-derived EVs were characterized using Western blot, Transmission Electron Microscopy, and NanoSight analysis, proving their integrity, size distribution, and stability. miRNome profiling identified enriched biological pathways related to cell migration, differentiation, and angiogenesis, emphasizing the critical role of EV cargo in promoting wound repair. In a murine model, hydrogels loaded with fibroblast-derived EVs significantly accelerated wound healing compared to controls (mean wound area 0.62 mm2 and 4.4 mm2, respectively), with faster closure, enhanced epithelialization, increased vascularization, and reduced fibrosis. Notably, the lyoprotectants successfully preserved the EVs’ structure and bioactivity during freeze-drying, reducing EVs loss by 35% compared to the control group and underscoring the feasibility of this approach for long-term storage and clinical application. Conclusions: This study introduces a novel scalable and adaptable strategy for regenerative medicine by combining fibroblast-derived EVs with GelMA, optimizing EVs’ stability and functionality for enhanced wound healing in clinical settings, even in challenging contexts such as combat zones or large-scale natural disasters.

Hypoxia-Inducible Factor Prolyl Hydroxylase Inhibitor Roxadustat Accelerates Wound Healing in a Mouse Hind limb Lymphedema Model.

Objective: Drugs regulating hypoxia-inducible factor (HIF)-1α have not been investigated for wound healing in lymphedema. Therefore, we examined the effects of drug modulation of HIF-1α activity for wound healing in our previously developed mouse model of nonirradiated hind limb lymphedema. Approach: Mouse hind limb lymphedema models (n = 17) and a sham group (n = 6) were created using 8- to 10-week-old male C57BL/6N mice. Mice with hind limb lymphedema were randomized into experimental groups receiving roxadustat, 3-(5'-hydroxymethyl-2'-furyl)-1-benzylindazole (YC-1), or dimethyl sulfoxide and were given intraperitoneal injections every 2 days for up to 2 weeks. Four days after the surgery, an 8-mm diameter full-thickness skin wound was created in the hind limb. The number of days required for wound closure and the percentage of wounds closed were measured. Skin samples taken at wound creation were evaluated by histological and molecular analysis. Results: Administration of roxadustat accelerated wound healing, whereas YC-1 delayed it, with a significant decrease and increase in skin thickness, respectively. The relative mRNA expression of Hif1α, matrix metalloproteinase-3, and interleukin-6 was significantly higher in the roxadustat group and that of metalloproteinase-9 was significantly lower in the roxadustat group compared with the control group. Innovation: This study is the first to demonstrate delayed wound healing in a mouse model of hind limb lymphedema and the first to demonstrate the promotion of significant wound healing through the use of roxadustat. Conclusion: Roxadustat exerts wound-healing effects and may promote the regulation of extracellular matrix remodeling via gene expression in hind limb lymphedema wound models.