Healing Of Full-thickness Skin Wounds Research Articles

Electrospun egg white/polyvinyl alcohol fiber dressing to accelerate wound healing

The purpose of this experiment was to prepare a new biological dressing for skin defect healing by electrospinning. Membranes consisting of egg white (EW) with 12% polyvinyl alcohol (PVA) solution (v/v, 60EW/40PVA, 50EW/50PVA, 40EW/60PVA) were obtained by electrospinning. The biological properties of the resulting fibrous membranes were tested in vitro and in vivo. Scanning electron microscopy (SEM) showed that the EW/PVA nanofiber membranes had a uniformly porous and smooth fibrous structure. The fiber thickened with increasing EW proportion. X-ray diffraction (XRD) showed that crosslinking improved the crystallinity of the composite fiber films. Fourier transform infrared (FT-IR) spectroscopy showed that PVA and EW existed independently in the composite fiber membranes after crosslinking. Mechanical tests showed that the tensile modulus and tensile strength of the fibrous membranes increased significantly after crosslinking. In vitro degradation experiments showed that crosslinking improved the stability of the EW/PVA nanofiber membranes in water. Cytotoxicity and cell proliferation tests proved the good biocompatibility of the fibrous membranes, with 60EW/40PVA significantly promoting cell proliferation. A full-thickness skin defect rat model confirmed that 60EW/40PVA significantly enhanced full-thickness skin wound healing and regeneration. This experiment verified the feasibility of using the EW/PVA composite material to prepare electrospun fiber dressings and promote skin defect repair and regeneration.

Biomimetic nanoengineered scaffold for enhanced full-thickness cutaneous wound healing

Wound healing is a complex process based on the coordinated signaling molecules and dynamic interactions between the engineered scaffold and newly formed tissue. So far, most of the engineered scaffolds used for the healing of full-thickness skin wounds do not mimic the natural extracellular matrix (ECM) complexity and therefore are not able to provide an appropriate niche for endogenous tissue regeneration [1]. To address this gap and to accelerate the wound healing process, we present biomimetic bilayer scaffolds compositing of gelatin nanofibers (GFS) and photocrosslinkable composite hydrogels loaded with epidermal growth factors (EGF). The nanofibers operate as the dermis layer, and EGF-loaded composite hydrogels acted as the epidermis matrix for the full-thickness wound healing application. The hydrogels are composed of gelatin metacryloyl (GelMA) modified with silicate nanoplatelets (Laponite). To overcome the challenges of transdermal delivery of EGF, including short half-life and lack of efficient formulation precise, controlled delivery was attained by immobilization of EGF on Laponite. It is shown that the addition of 1wt% silicate nanoplatelet increases the compressive modulus of the hydrogels by 170%. In vitro wound closure analysis also demonstrated improved adhesion of the scaffolds to the native tissue by 3.5 folds. Moreover, the tunable hemostatic ability of the scaffolds due to the negatively charged nanoplatelets is shown. In an established excisional full-thickness wound model, an enhanced wound closure (up to 93.1 ± 1.5%) after 14 days relative to controls (GFS and saline-treated groups) is demonstrated. The engineered adhesive and hemostatic scaffolds with sustained release of the growth factors have the potential to stimulate complete skin regeneration for full-thickness wound healing.

Multi-faceted enhancement of full-thickness skin wound healing by treatment with autologous micro skin tissue columns

Impaired wound healing is an immense medical challenge, and while autologous skin grafting remains the “gold-standard” therapeutic option for repairing wounds that cannot be closed by primary or secondary intention, it is limited by substantial donor site morbidity. We previously developed the alternative approach of harvesting full-thickness skin tissue in the form of “micro skin tissue columns” (MSTCs), without causing scarring or any other long-term morbidity. In this study we investigated how MSTC treatment affects the different cellular processes involved in wound healing. We found that MSTC-derived cells were able to remodel and repopulate the wound volume, and positively impact multiple aspects of the wound healing process, including accelerating re-epithelialization by providing multiple cell sources throughout the wound area, increasing collagen deposition, enhancing dermal remodeling, and attenuating the inflammatory response. These effects combined to enhance both epidermal and dermal wound healing. This MSTC treatment approach was designed for practical clinical use, could convey many benefits of autologous skin grafting, and avoids the major drawback of donor site morbidity.

The effects of Capparis ovata seed oil on the healing of traumatic skin wounds.

Capparis ovata contains alkaloids, lipids, polyphenols, flavonoids, and also is rich in antioxidants. Conventionally, in Turkey, the flower buds, root, bark, and fruits of C. ovata are used for their analgesic, anti-inflammatory, anti-rheumatism, tonic, and diuretic effects. The aim of this study was to examine the effect on wound healing of C. ovata seed oil (COSO), which is known to have antioxidant, anti-inflammatory, and antibacterial properties. In the study, 20 Wistar albino female rats were randomly divided into two groups of 10 animals each. A standard full-thickness skin defect was created on the back area of the rats. In both groups, after cleaning the wounds with saline daily, no active substance other than saline was applied to the control group, while 1 cc/day COSO was applied to the wounds of the rats in the study group. On the post-operative 14th day, the rats were reanesthetized and wound area measurements were made. Then, excision was performed to include 1 cm of intact tissue around the wound, which remained unhealed, and samples were taken for histopathological examination. The changes in wound areas showed that after 14 days, the improvement in the group treated with caper oil (32.78; 95% confidence interval, 17.21-48.36) was significantly higher than that of the control group (65.41; 95% confidence interval, 49.84-80.98) (p=0.009). The histopathological scores showed a significant difference between the groups in respect of epithelial formation, inflam-mation, and fibrosis development. No epithelial tissue formation was observed in the control group (90%), and more incomplete re-epithelization and focal epidermal hyperplasia were observed in the treatment group (60%). Fibrosis development was mild and weak (70%) in the control group and was evaluated as severe and intense (60%) in the treatment group. Perivascular edema was mild (50%) and vascularity was immature (60% - an indicator of neovascularization) in the treatment group. These histopathological results showed that the treatment group inflammation phase was completed and the proliferation phase started, as well as the effectiveness of the use of caper oil on epithelization, angiogenesis, and fibrosis, which are important histopathological parameters in the evaluation of wound healing compared to the control group. From the results of this study, it was concluded that COSO significantly enhances the healing of full-thickness skin wounds and this effect is primarily related to its anti-inflammatory effect.

Injectable Adhesive Self-Healing Multicross-Linked Double-Network Hydrogel Facilitates Full-Thickness Skin Wound Healing.

The development of natural polymer-based hydrogels, combining outstanding injectability, self-healing, and tissue adhesion, with mechanical performance, able to facilitate full-thickness skin wound healing, remains challenging. We have developed an injectable micellar hydrogel (AF127/HA-ADH/OHA-Dop) with outstanding adhesive and self-healing properties able to accelerate full-thickness skin wound healing. Dopamine-functionalized oxidized hyaluronic acid (OHA-Dop), adipic acid dihydrazide-modified HA (HA-ADH), and aldehyde-terminated Pluronic F127 (AF127) were employed as polymer backbones. They were cross-linked in situ using Schiff base dynamic covalent bonds (AF127 micelle/HA-ADH network and HA-ADH/OHA-Dop network), hydrogen bonding, and π-π stacking interactions. The resulting multicross-linked double-network design forms a micellar hydrogel. The unique multicross-linked double-network structure endows the hydrogel with both improved injection abilities and mechanical performance while self-healing faster than single-network hydrogels. Inspired by mussel foot adhesive protein, OHA-Dop mimics the catechol groups seen in mussel proteins, endowing hydrogels with robust adhesion properties. We also demonstrate the potential of our hydrogels to accelerate full-thickness cutaneous wound closure and improve skin regeneration with reduced scarring. We anticipate that our hydrogel platform based on a novel multicross-linked double-network design will transform the future development of multifunctional wound dressings.

Green fabrication of seedbed-like Flammulina velutipes polysaccharides–derived scaffolds accelerating full-thickness skin wound healing accompanied by hair follicle regeneration

A novel seedbed-like scaffold was firstly fabricated by the “frozen sectioning” processing method using Flammulina velutipes as a raw material. The Flammulina velutipes polysaccharides scaffold is composed of a natural structure imitating the “ground” (connected and aligned hollow tubes with porous walls). Meanwhile, its biologically active components include polysaccharides and proteins, mimicking the “plant nutrition” in the seedbed. To further optimize the ground and nutrition components, Flammulina velutipes polysaccharides–derived scaffolds (FPDSs) were fabricated via the treatment of original Flammulina velutipes polysaccharides scaffold (labeled FPS) by NaOH, cysteine (labeled as FPS/NaOH, FPS/Cys, respectively). FPDSs were characterized by SEM, FTIR, XRD, water absorption and retention, and mechanical evaluations. From the results, FPS/NaOH and FPS/Cys lost the characteristic big tubes of original strips and had higher water absorption capacities comparing to FPS. Simultaneously, FPS/NaOH had better ductility, FPS/Cys had showed increased stiffness. Biological activities of FPDSs were tested against different types of bacteria exhibiting excellent anti-bacterial activity, and FPS/NaOH and FPS/Cys had dramatically higher anti-bacterial activity than FPS. The cytocompatibility of FPDSs was evaluated utilizing mouse fibroblast cell line (L929), and all FPDSs showed good cytocompatibility. The FPDSs were further applied to a rat full-thickness skin wound model, and they all exhibited obviously accelerated re-epithelialization, among which FPS/NaOH showed the greatest efficiency. FPS/NaOH could shorten the wound-healing process as evidenced by dynamic alterations of the expression levels of specific stagewise markers in the healing areas. Similarly, FPS/NaOH can efficiently induce hair follicle regeneration in the healing skin tissues. In summary, FPDSs exhibit potential functions as seedbeds to promote the regeneration of the “seed” including hair follicles and injured skin, opening a new avenue for wound healing.

Full-thickness Skin Microcolumns Implanted into a Dermal Regeneration Template: A Novel Method for “Donor-free” Skin Replacement Therapy

BACKGROUND: Split-thickness skin graft is the current standard in the treatment of large full-thickness skin defects. The donor site resulting from tangential skin harvest is well recognized as painful and unsightly, even after it has healed. Several efforts have been made in the past to address this problem by limiting the amount of skin harvested while significantly expanding the skin elements (ReCell, Meek). These efforts suffer from short comings such as graft fragility and failure to achieve adequate closure in a reasonable period of time. Full-thickness skin columns are a novel concept in skin harvest with little to no donor site when the diameter of the columns falls below a certain threshold. There is also a theoretical advantage that the columns harvested contain elements of full-thickness skin including sweat glands and hair follicles. Here, we present 2 cases where full-thickness skin columns were harvested and implanted into a bilayer dermal regenerative template (Integra) to achieve durable single-stage skin replacement. METHODS: Wounds in 2 elderly patients were treated using standard excisional preparation techniques. Both patients refused a standard split-thickness skin graft with concerns of difficulty healing the donor site. Informed consent using full-thickness skin columns and Integra combination were obtained. Full-thickness skin columns were harvested from a small area of the upper thigh using skin biopsy punches (1.5–2 mm). The columns were implanted orthotopically into a sheet of Integra dermal matrix with the epidermis placed immediately deep to the silicone layer. The Integra-skin column composites were applied onto the wounds similar to a traditional skin graft. The punch biopsy donor sites were allowed to heal secondarily. RESULTS: Patient 1 was 90 years old and had a small lower extremity wound treated with 2 mm skin columns (n = 9) and a 3 × 1.5 cm2 Integra. Patient 2 was 88 years old had a larger volar forearm wound treated with 1.5 mm skin columns (n = 51) and an 8 × 5 cm2 Integra. Visual evaluation showed centripetal healing with epithelial cells radiating from the columns as well as from the periphery. Complete healing was achieved in 3–4 weeks; donor sites healed in less than a week with minimal evidence of skin harvest at 1 month. CONCLUSIONS: Full-thickness skin columns implanted into a dermal regeneration template represent a novel technique for skin replacement that allows single-stage healing of full-thickness skin wounds with little to no donor site, and without any biochemical processing of the tissue.

Antioxidant and anti-inflammatory activities of Prussian blue nanozyme promotes full-thickness skin wound healing

Excessive reactive oxygen species (ROS) and unresolved inflammations are the major causes of impaired wound healing as they overwhelm the cellular antioxidant system and impede the healing process. In this study, we examined the application of Prussian blue (PB) nanozyme as a novel material for cutaneous wound healing through the alleviation of excessive ROS and inflammation modulation. The PB nanoparticles not only exhibited hydrogen peroxide (H2O2) degradation activity but also showed strong superoxide scavenging ability. PB nanozyme mitigated the intracellular ROS at a high oxidative stress environment, resulting in a pronounced cytoprotective effect. Moreover, PB nanozyme also displayed significant anti-inflammatory activity, as evident from the suppression of inflammatory mediators in the lipopolysaccharide (LPS) induced macrophage cells. Encouraged by the in vitro results, we evaluated the in vivo therapeutic efficacy of PB nanozyme in a full-thickness cutaneous wound model combined with LPS treatment to mimic bacterial infection. The beneficial effects of topically applied PB nanozyme on wound healing and tissue regeneration were evident compared to the control. The periodical administration of a low amount (50 μg × 4) of PB nanoparticles exhibited faster wound closure as well as collagen deposition, maturation, and organization. Moreover, the PB treatment effectively induced the differentiation of keratinocytes, enhanced the neovascularization, and reduced macrophage burden in the entire wound site. Thus, PB nanozyme not only accelerated the healing process in an infection-mimicking cutaneous wound model but also exhibited tissue regeneration characteristics owing to the synergistic effect of ROS-scavenging and anti-inflammatory activities.

Low-drug resistance carbon quantum dots decorated injectable self-healing hydrogel with potent antibiofilm property and cutaneous wound healing

Local bacterial infection remains an increasingly severe threat to human health worldwide, and infection control is still a challenging task in clinics. Systemic administration of antibiotics usually causes adverse effects and bacterial resistance. Multi-functions hydrogel without drug-resistance is highly desired. Herein, we first synthesize antibacterial carbon quantum dots (CQDAG) with low-drug resistance using gentamicin sulfate and diammonium citrate as precursors. Then carboxymethyl chitosan (CMCS)-mixed CQDAG is reacted with oxidized dextran (ODex) through the Schiff base linkage to yield hydrogel network. Hydrogel decorated with 2 mg/mL CQDAG (CQDAG2-hydrogel) shows multi-functions including inherent self-healing, injectable, stretchable, compressive property, pH-dependent release of CQDAG and especially inhibiting biofilm formation, which are beneficial for treating bacterial infections. Besides, it is important that CQDAG2-hydrogel exhibits good cytocompatibility while sterilizing. In vivo antibacterial and wound healing evaluations demonstrate CQDAG2-hydrogel have the effect of anti-inflammation and promoting wound repair, which is manifested in wound healing rate, granulation tissue thickness and collagen disposition. The result indicates that the CQDAG2-hydrogel is excellent candidate for full-thickness skin wound healing.

Preparation and characterization of borosilicate-bioglass-incorporated sodium alginate composite wound dressing for accelerated full-thickness skin wound healing

Full-thickness skin injury is a serious and intractable clinical problem. Wound dressing is urgently needed to treat serious skin defects or induce skin reconstruction. For the first time, we demonstrated a borosilicate bioglass (BBG)-incorporated sodium alginate (SA) wound dressing by a simple and effective technique for accelerated wound healing. The physical and chemical properties, in vitro and in vivo properties of SA-BBG composite wound dressing have been investigated. The results show that the SA-BBG composite dressing possesses good water absorption performance. The boron and silicon ions in BBG can maintain stable and sustained release. Most importantly, the SA-BBG composite wound dressing shows outstanding wound healing ability in full-thickness skin defects in rats. The wounds treated with SA-BBG composite dressing groups had almost closed at day 15. When the ratio of sodium alginate to bioglass in the sponge is 3:1, the wound healing effect is the best. In conclusion, the SA-BBG composite dressing shows great potential for application in skin wound healing and SA3BBG works best.

Extracellular vesicle-enclosed miR-486-5p mediates wound healing with adipose-derived stem cells by promoting angiogenesis.

Adipose‐derived stem cells (ASC) are said to have a pivotal role in wound healing. Specifically, ASC‐secreted extracellular vesicles (EV) carry diverse cargos such as microRNAs (miRNAs) to participate in the ASC‐based therapies. Considering its effects, we aimed to investigate the role of ASC‐EVs in the cutaneous wound healing accompanied with the study on the specific cargo‐medicated effects on wound healing. Two full‐thickness excisional skin wounds were created on mouse dorsum, and wound healing was recorded at the indicated time points followed by histological analysis and immunofluorescence staining for CD31 and α‐SMA. Human skin fibroblasts (HSFs) and human microvascular endothelial cells (HMECs) were co‐cultured with EVs isolated from ASC (ASC‐EVs), respectively, followed by the evaluation of their viability and mobility using CCK‐8, scratch test and transwell migration assays. Matrigel‐based angiogenesis assays were performed to evaluate vessel‐like tube formation by HMECs in vitro. ASC‐EVs accelerated the healing of full‐thickness skin wounds, increased re‐epithelialization and reduced scar thickness whilst enhanced collagen synthesis and angiogenesis in murine models. However, miR‐486‐5p antagomir abrogated the ASC‐EVs‐induced effects. Intriguingly, miR‐486‐5p was found to be highly enriched in ASC‐EVs, exhibiting an increase in viability and mobility of HSFs and HMECs and enhanced the angiogenic activities of HMECs. Notably, we also demonstrated that ASC‐EVs‐secreted miR‐486‐5p achieved the aforesaid effects through its target gene Sp5. Hence, our results suggest that miR‐486‐5p released by ASC‐EVs could be a critical mediator to develop an ASC‐based therapeutic strategy for wound healing.

High porous electrospun poly(ε-caprolactone)/gelatin/MgO scaffolds preseeded with endometrial stem cells promote tissue regeneration in full-thickness skin wounds: An in vivo study.

In the current study, electrospun poly(ε-caprolactone)-gelatin (PCL-Gel) fibrous scaffolds containing magnesium oxide (MgO) particles and preseeded with human endometrial stem cells (hEnSCs) were developed to use as wound care material in skin tissue engineering applications. Electrospun fibers were fabricated using PCL-Gel (1:1 [wt/wt]) with different concentrations of MgO particles (1, 2, and 4 wt%). The fibrous scaffolds were evaluated regarding their microstructure, mechanical properties, surface wettability, and in vitro and in vivo performances. The full-thickness excisional wound model was used to evaluate the in vivo wound healing ability of the fabricated scaffolds. Our findings confirmed that the wounds covered with PCL-Gel fibrous scaffolds containing 2 wt% MgO and preseeded with hEnSCs have nearly 79% wound closure ability while sterile gauze showed 11% of wound size reduction. Our results can be employed for biomaterials aimed at the healing of full-thickness skin wounds.

Influence of human amniotic mesenchymal stem cells on macrophage phenotypes and inflammatory factors in full-thickness skin wounds of mice

Objective: To explore the influence of human amniotic mesenchymal stem cells (hAMSCs) on the in vivo and in vitro regulation of macrophage phenotypes and inflammatory factors associated with wound healing of full-thickness skin wounds in mice. Methods: Fresh amniotic membrane discarded from full-term delivery by 5 healthy pregnant women in the Department of Obstetrics and Gynecology of the Affiliated Hospital of Zunyi Medical University was used for the isolation and culture of hAMSCs by enzyme digestion method. The third passage of cells was used for identification of adipogenic and osteogenic differentiation. The fourth passage of cells was used for identification of hAMSCs surface markers. Ten C57BL/6 mice (all male, aged 6 to 8 weeks, the same gender and age below) were selected for extracting mouse peritoneal macrophages by intraperitoneal lavage, and M1-type macrophages were induced by Dulbecco's modified eagle medium (DMEM) medium containing interferon-γ. The M1-type macrophages were divided into hAMSCs+ macrophage group and macrophage alone group. Then 1×10(4) hAMSCs/per well of fourth passage were added to macrophage in hAMSCs+ macrophage group and cultured in 2 mL DMEM medium for routine culture. In macrophage alone group, each well was only added with 2 mL DMEM medium for routine culture. On day 1 and 7 in culture, the content of interleukin-12 (IL-12), arginase 1, and IL-10 in the cell culture supernatant of the 2 groups were detected by enzyme-linked immunosorbent assay with sample number of 6/per group. (2) Full-thickness skin wound model was reproduced in the back of 56 C57BL/6 mice, which were divided into hAMSCs group and phosphate buffer solution (PBS) group using the random number table, with 28 mice in each group. Mice in hAMSCs group were subcutaneously injected with 100 μL of cell suspension containing 1×10(7) hAMSCs per mL in PBS suspension along the wound edge. While mice in PBS group were only subcutaneously injected with 100 μL PBS along the wound edge. On post injection day (PID) 1, 3, 7, and 14, 7 mice in the two groups were sacrificed respectively. Histopathological observation was performed with hematoxylin-eosin staining. The expressions of macrophage surface markers [CD68 and inducible nitric oxide synthase (iNOS) double positive cells and CD68 and arginase 1 double positive] in the wounds were detected by immunofluorescent staining. The mRNA expressions of IL-10, macrophage inflammatory protein 1α (MIP-1α), and MIP-2 in the wounds were detected by real-time fluorescent quantitative reverse transcription polymerase chain reaction. Data were statistically analyzed with analysis of variance for factorial design, t test, and Bonferroni correction. Results: (1) On day 1 in culture, the content of IL-12 and arginase 1 in the cell culture supernatant of the two groups were similar (t=0.448, 0.536, P>0.05), and the content of IL-10 in the cell culture supernatant of hAMSCs+ macrophage group was significantly lower than that in macrophage alone group (t=14.722, P 0.05). On PID 3 and 7, the percentages of CD68 and iNOS double positive cells in the wounds in hAMSCs group were significantly lower than those of PBS group (t=6.396, 4.787, P 0.05). On PID 3, 7, and 14, the mRNA expressions of IL-10 in the wounds of mice in hAMSCs group were significantly higher than those of PBS group (t=7.758, 124.355, 80.823, P<0.01). On PID 1, 3, 7, and 14, the mRNA expressions of MIP-1α and MIP-2 in the wounds of mice in hAMSCs group (0.341±0.212, 0.648±0.004, 0.611±0.106, 0.763±0.049, 1.377±0.099, 1.841±0.042, 1.181±0.035, 0.553±0.028) were significantly lower than those of PBS group (3.853±0.035, 6.914±0.163, 3.648±0.113, 2.250±0.046, 11.119±0.495, 8.634±0.092, 5.722±0.021, 4.862±0.036, t=43.198, 101.904, 51.845, 58.231, 51.074, 177.501, 291.752, 251.614, P<0.01). Conclusions: hAMSCs demonstrates biological effects of promoting the transformation of M1-type macrophages into M2-type macrophages in full-thickness skin wounds of mice. They can up-regulate the expression of anti-inflammatory and anti-fibrotic factor IL-10, and down-regulate the expression of important inflammation mediated factors MIP-1α and MIP-2.

PF-127 hydrogel plus sodium ascorbyl phosphate improves Wharton\u2019s jelly mesenchymal stem cell-mediated skin wound healing in mice

BackgroundFactors such as poor engraftment, retention, and survival of the transplanted stem cells are deemed to limit their therapeutic efficacy for wound regeneration. Hence, it is necessary to explore these issues in order to resolve them. In this study, we aim to investigate the role of Pluronic F-127 (PF-127) hydrogel plus antioxidant sodium ascorbyl phosphate (SAP) in enhancing Wharton’s jelly mesenchymal stem cell (WJMSC)-mediated effectiveness on full-thickness skin wound healing in mice.MethodsFirst, the cytotoxicity of PF-127 and the biological effect of SAP on the survival of WJMSCs were tested in vitro using cell viability and proliferation assays. Next, a cell suspension containing WJMSCs, PF-127, and SAP was topically administered onto an 8-mm diameter excisional full-thickness wound bed. Eight days after transplantation, the mice were sacrificed and the skin tissue was excised for histological and immunohistochemical analysis. Finally, in vivo distribution of transplanted WJMSCs was traced to investigate cell engraftment and the potential therapeutic mechanism.ResultsPF-127 was found to be cytotoxic to WJMSCs while SAP significantly improved the survival of PF-127-embedded WJMSCs. When this combination was topically transplanted onto the wound bed, wound healing was facilitated and dermis regeneration was achieved on the 8th day after surgery, as evidenced by an increase in dermal thickness, newly developed hair follicles, and collagen fiber deposition accompanied by a reduction in scar width. Further, immunohistochemical analysis demonstrated a higher number of anti-inflammatory M2 macrophages, proliferating cells, and newly formed blood vessels in the WJMSCs/PF-127/SAP group relative to all other groups. In addition, in vivo tracking results revealed a highly enhanced engraftment of WJMSCs accumulated in the dermis in the WJMSCs/PF-127/SAP group.ConclusionsSAP significantly improves the survival of WJMSCs in PF-127 encapsulation. Further, PF-127 plus SAP is an effective combination that enhances WJMSC engraftment in the dermis, which then promotes full-thickness wound healing through potential M2 macrophage formation and angiogenesis.

Wound healing in immunocompromised dogs: A comparison between the healing effects of moist exposed burn ointment and honey

Background and Aim:Natural topical products have been used to enhance wound healing, especially in immunocompromised animals. The aims of this study were to evaluate and to compare the effects of moist exposed burn ointment (MEBO) and honey on the healing of full-thickness skin wounds in immunocompromised dogs.Materials and Methods:The study was conducted using 12 adults, apparently healthy mongrel dogs. Immunosuppression was induced in six dogs by oral administration of prednisone (2 mg/kg) and azathioprine (2 mg/kg), once a day for 21 days. On each dog, a total of 9, 1.5 cm in diameter full-thickness skin circular wounds were created aseptically in the thoracolumbar area under general anesthesia using customized skin punch biopsy kit. In a random fashion, three wounds in each dog were treatment using MEBO (contains b-sitosterol, baicalin, and berberine as active ingredients in a base of beeswax and sesame oil), honey or no treatment (control), once per day for 21 days. Wounds were grossly evaluated once a day for signs of inflammation or infection. In addition, biopsy specimens and digital imaging data of each wound were obtained on days 7, 14, and 21 for histopathological evaluation of the healing process.Results:Wounds in immunocompromised dogs appeared to heal significantly in a slower fashion than in non-immunocompromised counterparts. Digital analysis data showed that MEBO-treated wounds expressed better epithelialization area, faster contraction, and smaller wound area percentage when compared with honey-treated wounds. Histopathological analysis showed significantly higher angiogenesis scores in MEBO-treated wounds when compared with other treatments.Conclusion:Results of this study showed that MEBO resulted in significant enhancement of wound healing in both healthy and immunocompromised dogs. However, when compared to honey, the wound healing effect of MEBO was superior to that of honey.

Healing of Full-Thickness Murine Skin Wounds Containing Nanofibers Using Splints for Efficient Reepithelialization and to Avoid Contracture.

Wound healing process is the outcome of a series of actions and combined with collaborative process involving concerted efforts of multiple cell types. The dynamic series of events constituting each of these overlapping rather than discrete stages of wound healing increases its complexity and the necessity to understand it. The contrasting mechanisms of wound healing employed by mouse (via wound contraction) and humans (via reepithelialization) puts forth the need of a model closely mimicking human wound-healing and hence comes the applicability of the mouse excisional wound splinting model. Use of silicone-based splints has demonstrated their effectiveness in aptly resembling the human reepithelialization mediated wound healing by preventing contraction during healing. The rising popularity of nanofiber-based treatments for wound healing through sustained release of factors/molecules promoting wound closure can be potentially implemented in association with this model to determine its efficacy in wound management in a more humanized way.

Regenerative porcine dermal collagen matrix developed by supercritical carbon dioxide extraction technology: Role in accelerated wound healing

A novel collagen matrix was developed to accelerate wound healing for hard to heal or delayed wound healing clinical conditions. It is produced from porcine skin, chemically comparable and biocompatible to the human skin. Supercritical carbon dioxide (SCCO2) was employed to decellularize porcine skin to produce collagen matrix (CM). To confirm the complete decellularization of the CM, hematoxylin and eosin staining, and DNA contents were analyzed. In addition, we analyzed the chemical content and structural property. In vitro, in vivo toxicity and biocompatibility was evaluated for CM. In addition, wound healing was evaluated in a porcine excision full-thickness skin wound model mimicking human wound healing. SCCO2 produced CM exhibited complete decellularization, the chemical content was found to be type I collagen and characteristic features were similar to that of human. CM was found to be non-toxic in all the toxicological tests. In addition, CM exhibited excellent biocompatibility in both in vitro and in vivo studies. In porcine excision full-thickness skin wound healing model, CM alone and cocultured with fibroblast and keratinocytes exhibited decreased inflammation, complete epithelization and enhanced wound healing. To conclude, CM produced by SCCO2 technology revealed chemically similar to human skin type I collagen, non-toxic, good biocompatibility and accelerated wound healing in porcine excision full-thickness skin wound model. Statement of significanceAs far as our knowledge, we are the first to report the SCCO2 extraction technology to decellularize the porcine skin to produce and characterize collagen matrix. We evaluated in vitro and in vivo biocompatibility of the collagen matrix. Furthermore, we investigated the regenerative efficacy of collagen matrix on excision full-thickness skin wound healing model in the pig. We proved the complete decellularization of porcine skin by SCCO2 extraction technology to produce collagen matrix. In addition, it demonstrated to be excellently biocompatible in both in vitro and in vivo tests, without adverse effects. The present study demonstrated that the collagen matrix developed by SCCO2 extraction technology could be a perfect and beneficial wound healing and regenerative matrix in tissue engineering.

Effects of Azelnidipine-Carboxymethylcellulose Gel on Healing of Full-Thickness Skin Wounds in Streptozotocin Induced Diabetic Rats.

ObjectiveTo evaluate the effects of azelnidipine-carboxyl methyl cellulose (AZL-CMC) gel and carboxyl methyl cellulose 2% gel (CMC) on the healing of full-thickness skin wounds of diabetic rats.MethodsFifteen Sprague Dawley male rats were studied. The rats were divided into three groups: AZL-CMC gel-treated, CMC 2% gel-treated, and control group. Wounds were assessed by wound area measurement every 3 days and histopathology samples were collected at 4, 7 and 12 days post wounding to evaluate the healing process using stereological study. Mann–Whitney U-test repeated measurement and non-parametric one-way analysis of variance (ANOVA) were used to analyze the data using SPSS, version 18.ResultsNumerical density of the fibroblasts of the AZL-CMC gel treated group was 59.17±2.69 (×104/mm3) and higher than the control 22.64±1.34 (×104/mm3) and CMC 2%-treated groups 40.80±5.27 (×104/mm3), respectively, P<0.001. The volume density of the collagen bundles and LV of the vessels were 83.1±4.46 and 42.16±5.78, respectively, in the AZL-CMC treated group, and higher compared to the control (53.96±5.07, 9.9±2.49) and the CMC 2%-treated (65.88±2.13, 18.1±2.20) groups (P <0.001).ConclusionThe healing of AZL-CMC gel-treated wound was better than the control wounds, grossly. Wound healing processes and wound closure in the intervention group began sooner and was completed more quickly. The quantitative and qualitative parameters showed the significant wound healing effect of the AZL-CMC gel-treated group.

Anti-oxidant electroactive and antibacterial nanofibrous wound dressings based on poly(ε-caprolactone)/quaternized chitosan-graft-polyaniline for full-thickness skin wound healing

Developing a novel nanofibrous wound dressing with multi-functional properties, integrating suitable mechanical property, electroactivity, anti-oxidant and inherent antibacterial activity to promote wound healing process is urgently desired, which could meet the increasing requirements of clinical needs. Herein, a series of antibacterial, anti-oxidant and electroactive nanofibrous membranes were fabricated by electrospinning poly(ε-caprolactone) (PCL) and quaternized chitosan-graft-polyaniline (QCSP) polymer solutions which combined the good mechanical property of PCL and multi-functionality of QCSP. The nanofibrous wound dressings exhibited electroactivity, similar mechanical properties to soft tissue, free radical scavenging capacity, antibacterial property, and biocompatibility. In particular, PCL/QCSP15 (15 wt% of QCSP in the sample) showed a good balanced ability between antibacterial activity and cell proliferation, which significantly accelerated the healing process of wound in a mouse full-thickness wounds defect model than commercial dressing (Tegaderm™ Film) and pure PCL (PCL/QCSP0) nanofibrous membrane. Moreover, the histopathological examination and immunofluorescence staining showed that the wounds treated by PCL/QCSP15 nanofiber dressing exhibited higher collagen deposition, granulation tissue thickness, and more angiogenesis. In one word, these antibacterial, anti-oxidant, electroactivity nanofibrous membranes showed promising applications for full-thickness skin repair.

Effect of iPSCs-derived keratinocytes on healing of full-thickness skin wounds in mice

Induced pluripotent stem cells (iPSCs) provide new approaches for the management of severe skin wound healing due to their infinite proliferative capacity, pluripotency into multiple lineages, and important ethical acceptability. In this study, we aimed to differentiate iPSCs into keratinocytes and to observe the therapeutic effects of transplanted iPSCs-derived keratinocytes on wound healing in mice. Here, mouse iPSCs had been successfully differentiated into keratinocytes. Next, iPSCs-derived keratinocytes labeled by CSFE were injected directly into the full-thickness skin wound. Hematoxylin & Eosin, Masson's trichrome, EdU staining and immunohistochemical staining were performed to assess the effects of iPSCs-derived keratinocytes on wound healing. Our results showed that transplantation of iPSCs-derived keratinocytes into full-thickness skin wound site accelerated re-epithelialization and reduced scar formation. In addition, we found that conditioned medium of iPSCs-derived keratinocytes reduced the expression of α-SMA and COL1 and increased the expression of MMP1 in fibroblasts in vitro. Further mechanism studies show the TNF-α-induced activation of NF-κB is involved in the effect of conditioned medium of iPSCs-derived keratinocytes on fibroblasts. In conclusion, this study has shown that iPSCs-derived keratinocytes decrease the healing time by increasing the epithelization rate and reduce scarring, suggesting a possible new treatment for skin wound healing.