Mechanical Stimulation of Anti-Inflammatory and Antioxidant Hydrogels for Rapid Re-Epithelialization.

The epithelium, an essential barrier to protect organisms against infection, exists in many organs. However, rapid re-epithelialization to restore tissue integrity and function in an adverse environment is challenging. In this work, a long-term anti-inflammatory and antioxidant hydrogel with mechanical stimulation for rapid re-epithelialization, mainly composed of the small molecule thioctic acid, biocompatible glycine, and γ-Fe2O3 nanoparticles is reported. Glycine-modified supramolecular thioctic acid is stable and possesses outstanding mechanical properties. The incorporating γ-Fe2O3 providing the potential contrast function for magnetic resonance imaging observation, can propel hydrogel reconfiguration to enhance the mechanical properties of the hydrogel underwater due to water-initiated release of Fe3+. In vitro experiments show that the hydrogels effectively reduced intracellular reactive oxygen species, guided macrophages toward M2 polarization, and alleviated inflammation. The effect of rapid re-epithelialization is ultimately demonstrated in a long urethral injury model in vivo, and the mechanical stimulation of hydrogels achieves effective functional replacement and ultimately accurate remodeling of the epithelium. Notably, the proposed strategy provides an advanced alternative treatment for patients in need of large-area epithelial reconstruction.

Beta-caryophyllene as an antioxidant, anti-inflammatory and re-epithelialization activities in a rat skin wound excision model.

The skin is a critical organ for the maintenance of the integrity and protection of the organism. When a wound occurs, a sequence of healing mechanisms is triggered to reconstruct the wounded area. ß-caryophyllene is a sesquiterpene in Copaifera langsdorffii oleoresin with antioxidant and anti-inflammatory potential. On the basis of previous studies with C. langsdorffii, ß-caryophyllene was selected to evaluate its wound healing potential and pharmacological mechanisms. The excision wound model was used with male Wistar rats and macroscopic, histological, immunohistochemical and biochemical analyses were performed with skin samples, comparing the ß-caryophyllene-treated group with reference drugs. The results showed macroscopic retraction of the wounds treated with ß-caryophyllene. Biochemical assays revealed the antioxidant and anti-inflammatory mechanisms of the ß-caryophyllene-treated group with increasing levels of IL-10 and GPx and decreasing levels of pro-inflammatory molecules, including TNF-α, IFN-γ, IL-1ß and IL-6. After ß-caryophyllene treatment, immunohistochemical assays showed enhanced re-epithelialization, through the increase in laminin-γ2 and desmoglein-3 immunolabeling. ß-caryophyllene also act in the remodeling mechanism, increasing the collagen content in the Masson's trichrome staining. These findings indicated the wound-healing potential of ß-caryophyllene topical formulation in rat skin wounds, mediated by antioxidant, anti-inflammatory and re-epithelialization mechanisms.

Perianal Application of Glyceryl Trinitrate Ointment Versus Tocopherol Acetate Ointment in the Treatment of Chronic Anal Fissure: A Randomized Clinical Trial.

BACKGROUND: Medical treatment, including glyceryl trinitrate ointment, represents the first step for the management of chronic anal fissure. However, glyceryl trinitrate ointment is associated with headache and, consequently, a high withdrawal rate of the treatment. OBJECTIVE: The aim of the present study was to evaluate the effect of the topical application of tocopherol acetate ointment on pain relief and chronic anal fissure epithelialization, comparing it with the effect of a standard treatment with glyceryl trinitrate ointment. DESIGN: This is a 2-parallel-group, single-center, randomized controlled, intent-to-treat clinical trial. SETTINGS: This study was conducted at the Garcilaso Clinic affiliated with Universidad Alfonso X (Madrid, Spain). PATIENTS: Patients with chronic anal fissure were selected. INTERVENTIONS: Patients were randomly assigned into 2 groups: patients receiving tocopherol acetate ointment and patients receiving glyceryl trinitrate ointment. MAIN OUTCOME MEASURES: The primary end point was quantification of anal pain 8 weeks after beginning the treatment as measured by a Visual Analogue Scale ranging from 0 to 100 mm. The secondary end points were the healing rate (during the treatment period of 8 weeks) and the recurrence rate. RESULTS: One hundred sixty consecutive patients were treated, 80 in each group. By 8 weeks after treatment, mean anal pain score declined by 56.2 mm in the glyceryl trinitrate ointment group compared with a mean anal pain score decline of 67.1 mm in the tocopherol acetate ointment group (mean difference, 10.9 mm (95% CI, 4.3-18.6); p = 0.018). Sixteen weeks after finishing the therapy, the recurrence rate was 13.2% in the glyceryl trinitrate ointment group vs 2.9 in the tocopherol acetate ointment group (p = 0.031). LIMITATIONS: Limitations of the study include the absence of manometric measurements of the internal anal sphincter before and after the treatments and the use of glyceryl trinitrate ointment as an active comparator, whereas calcium channel blockers are actually the standard treatment. CONCLUSIONS: Anal pain was significantly lower in the tocopherol acetate ointment group than in the glyceryl trinitrate ointment group at 8 weeks after treatment. Tocopherol acetate ointment achieved a greater healing rate and a lower recurrence rate 16 weeks after finishing the treatment. See Video Abstract at http://links.lww.com/DCR/B751. REGISTRATION: URL: https://www.clinicaltrials.gov; Identifier: NCT03787030.APLICACIÓN PERIANAL DE POMADA DE TRINITRATO DE GLICERILO FRENTE A LA POMADA DE ACETATO DE TOCOFEROL EN EL TRATAMIENTO DE LA FISURA ANAL CRÓNICA: UN ENSAYO CLÍNICO ALEATORIZADOANTECEDENTES:El tratamiento médico, incluida la pomada de trinitrato de glicerilo, representa el primer paso para el tratamiento de la fisura anal crónica. Sin embargo, la pomada de trinitrato de glicerilo se asocia con cefalea y, en consecuencia, una alta tasa de cancelación del tratamiento.OBJETIVO:El objetivo del presente estudio fue evaluar el efecto de la aplicación tópica de pomada de acetato de tocoferol en el alivio del dolor y la epitelización de la fisura anal crónica, comparándolo con el efecto de un tratamiento estándar con pomada de trinitrato de glicerilo.DISEÑO:Ensayo clínico con intención de tratar controlado, aleatorizado, de un solo centro, con dos grupos paralelos.ESCENARIO:Clínica Garcilaso adscrita a la Universidad Alfonso X (Madrid, España).PACIENTES:Pacientes con fisura anal crónica.INTERVENCIONES:Los pacientes fueron aleatorizados en 2 grupos: pacientes que recibieron pomada de acetato de tocoferol y pacientes que recibieron pomada de trinitrato de glicerilo.PRINCIPALES MEDIDAS DE RESULTADO:El criterio de valoración principal fue la cuantificación del dolor anal 8 semanas después de comenzar el tratamiento, medido por la escala analógica visual que varía de 0 a 100 mm. Los criterios de valoración secundarios fueron la tasa de curación (durante el período de tratamiento de 8 semanas) y la tasa de recurrencia.RESULTADOS:Se trataron ciento sesenta pacientes consecutivos, 80 en cada grupo. A las ocho semanas después del tratamiento, la puntuación media de dolor anal se redujo en 56.2 mm en el grupo de pomada de trinitrato de glicerilo en comparación con una disminución de la puntuación de dolor anal medio de 67.1 mm en el grupo de pomada de acetato de tocoferol (diferencia media: 10.9 mm (intervalo de confianza del 95%; 4.3 a 18.6; p = 0.018) Dieciséis semanas después de finalizar la terapia, la tasa de recurrencia fue del 13.2% en el grupo de pomada de trinitrato de glicerilo frente a 2.9 en el grupo de pomada de acetato de tocoferol (p = 0.031).LIMITACIONES:Ausencia de medidas manométricas del esfínter anal interno antes y después de los tratamientos. Ungüento de trinitrato de glicerilo como comparador activo, mientras que los bloqueadores de los canales de calcio son en realidad el tratamiento estándar de oro.CONCLUSIONES:El dolor anal fue significativamente menor en el grupo de ungüento de acetato de tocoferol que en el grupo de ungüento de trinitrato de glicerilo a las 8 semanas después del tratamiento. La pomada de acetato de tocoferol logró una mayor tasa de curación y una menor tasa de recurrencia 16 semanas después de finalizar el tratamiento. Consulte Video Resumen en http://links.lww.com/DCR/B751. (Traducción-Dr. Jorge Silva Velazco).

Diethylenetriamine/NONOate-doped alginate hydrogel with sustained nitric oxide release and minimal toxicity to accelerate healing of MRSA-infected wounds.

This study demonstrates the development of a nitric oxide (NO)-releasing hydrogel wound dressing and its efficacy at accelerating methicillin-resistant Staphylococcus aureus (MRSA)-infected wound healing. A DETA/NONOate-doped alginate (Alg-DETA/NO) hydrogel was synthesized using alginate as a hydrogel-forming wound dressing material and diethylenetriamine/diazeniumdiolate (DETA/NONOate) as an NO donor. Alg-DETA/NO exhibited a prolonged NO release profile over a period of 4 days. The rheological properties of Alg-DETA/NO did not differ significantly from those of pure alginate. Importantly, Alg-DETA/NO showed potent antibacterial activity against MRSA, with minimal toxicity to mouse fibroblasts. The application of Alg-DETA/NO to MRSA-infected wounds in a mouse model showed a favorable wound healing with accelerated wound-size reduction and reduced skin bacterial infection. Additionally, histological examination revealed that Alg-DETA/NO reduced inflammation at the wound site and promoted re-epithelialization, angiogenesis, and collagen deposition. Thus, Alg-DETA/NO presented herein could serve as a safe and potent hydrogel dressing for the treatment of MRSA-infected wounds.

Comparative analysis of the hemostatic, analgesic and healing effects of cyanoacrylate on free gingival graft surgical wounds in donor and recipient areas: a systematic review.

To analyze the hemostatic, Dsurgical wounds in donor and recipient areas of free gingival grafts (FGG). Five databases (PubMed, Scopus, Science Direct, Cochrane and Web of Science) were searched up to March 2021 (PROSPERO CRD42019134497). The focus of the study (cyanoacrylate) was combined with the condition (periodontal surgery OR free gingival graft OR free soft tissue graft OR autografts), and outcome (healing OR epithelialization OR pain OR analgesia OR bleeding OR hemostasis OR hemostatic). Studies reporting cyanoacrylate isolated or associated with another substance in FGG stabilization and closure were investigated and assessed for the quality and risk of bias through the Cochrane Manual. Six studies with 323 participants were included. Evaluation of the quality and risk of bias highlighted a low risk for four articles, intermediate for one and unclear for another. The use of cyanoacrylate associated or not with the hemostatic sponge or the platelet-rich fibrin was more effective in healing (three studies), analgesia (four studies), and hemostasis in one study (p < 0.05). However, groups with the association in cyanoacrylate showed superior healing, and analgesic action to the isolated cyanoacrylate group. In addition, two studies demonstrated that cyanoacrylate use reduces surgery duration, one study showed that it reduces postoperative sensibility, and another present hemostatic effect (p < 0.05). There is scarce literature for the use of cyanoacrylate in FGG wounds indicates that it can promote a minor inflammatory response, reduce operation time, does not interfere with healing, relieves postoperative discomfort, and suggests the possibility immediate hemostasis. Its use presents an alternative to suturing in FGG surgeries. But, the limited number of cases and the relative heterogeneity of the included studies suggest caution in generalizing the indication. CLINICAL RELEVANCE: Cyanoacrylate seems to present analgesic effects and less pain when applied to wound closure and covering donor and recipient areas reducing the need for postoperative analgesic medication; and has a healing effect in the closure of the donor area on the palate. In addition, it can reduce bleeding time after surgery, and prevents late bleeding during the first postsurgical week. Scientific justification: To evaluate the hemostatic, analgesic and healing actions of cyanoacrylate compared to the suture thread and other agents when used to close surgical wounds from periodontal free gingival graft surgical wounds in both the donor and recipient areas of the graft. MAIN FINDINGS: The use of cyanoacrylate individually or in association with wound dressing agents presents analgesic effects because the patient reports less pain experienced when cyanoacrylate is applied to the wound closure and covering, thereby reducing the need for postoperative analgesic medication. In addition, a healing effect is observed in the closure of the donor area on the palate; as well as it seems to present hemostatic effects, reducing the bleeding time after surgery, and preventing late bleeding during the first postsurgical week. PRACTICAL IMPLICATIONS: Dentists may cautiously apply cyanoacrylate after periodontal surgeries for free gingival graft in both the donor and recipient areas of the graft. However, they must consider the limitations of the surgery, tension-free positioning, the patient's dyscrasia and postoperative care, constituting a set of predictors for adequate clinical decision-making. Widespread use of such material for all patients and surgical configurations may not be recommended.

Studies on novel chitosan/alginate and chitosan/bentonite flexible films incorporated with ZnO nano particles for accelerating dermal burn healing: In vivo and in vitro evaluation.

This research work was performed to prepare chitosan-alginate-gelatin and chitosan-bentonite-gelatin films in different mass ratios incorporated with nano particles of Zinc Oxide, which were achieved through the method of green synthesis from Nettle leaf extract. The films were prepared and characterized based on their physicochemical properties, such as water absorption and porosity and surface morphology. Bentonite containing films illustrate more flexibility than alginate ones while the chitosan/bentonite composite films have a maximum water absorption capacity of about 170%. The antibacterial activity of the films was investigated against Staphylococcus aureus and Pseudomonas aeruginosa bacteria and it presents good inhibitory activities against the tested bacteria as compared to the control sample. Furthermore, vivo animal tests were performed to confirm the applicability of the prepared films as a healing material for burned skin. Skin appendages, such as hair follicles and sebaceous gland in the dermis, were detected in normal structures by applying both of the composites to damaged skin. In the control sample (gauze), no re-epithelialized area was observed, except in close proximity of the wound border. The results show that due to its full coverage of the wounds with new epithelium and hair follicles, bentonite-containing composites are more preferred.

Bioactive anti-oxidative polycaprolactone/gelatin electrospun nanofibers containing selenium nanoparticles/vitamin E for wound dressing applications.

In this study, polycaprolactone/gelatin (PCL/GEL) electrospun nanofibers containing biogenic selenium nanoparticles (Se NPs) and Se NPs/vitamin E (VE) with average diameters of 397.8 nm and 279.5 nm, respectively (as determined by SEM inspection) were prepared and their effect on wound healing was evaluated using in-vivo studies. The energy dispersive X-ray (EDX) mapping, TEM micrograph, and FTIR spectra of the prepared nanofibers strongly demonstrated well entrapment of Se NPs and VE into scaffolds. An amount of 57% Se NPs and 43% VE were gradually released from PCL/GEL/Se NPs/VE scaffold after 4 days immersion in PBS solution (pH 7.4). The both PCL/GEL/Se NPs and PCL/GEL/Se NPs/VE scaffolds supported 3T3 cell proliferation and attachment as confirmed by MTT assay and SEM imaging. Complete re-epithelialization, low level of edema and inflammatory cells in coordination with high level of oriented collagens demonstrated the wound healing activity of PCL/GEL/Se NPs/VE. Besides, significant antioxidant efficacy of PCL/GEL/Se NPs and PCL/GEL/Se NPs/VE scaffolds was demonstrated according to GSH and MDA assays. To sum up, the prepared PCL/GEL/Se NPs/VE scaffold in the present study represented suitable healing effect on animal model which candidate it for further studies.

Healing potential of Spirulina platensis for skin wounds by modulating bFGF, VEGF, TGF-ß1 and α-SMA genes expression targeting angiogenesis and scar tissue formation in the rat model.

Blue-green microalga Spirulina platensis (SP) gained more attention for its antioxidant and/or anti-inflammatory properties magnifying its beneficial effects as a feed additive and for cosmetic and biomedical applications. This study was performed to examine the impact of SP on the cutaneous wound and burn healing and to develop an understanding of the correlation between the sequelae of wound healing and the molecular expression patterns of wound healing-related genes as angiogenic basic fibroblast growth factor (bFGF) and vascular endothelial growth factor (VEGF) and fibrosis-related genes as transforming growth factor-ß (TGF-ß) and α-smooth muscle actin (α-SMA) in rat wound models. To achieve these goals, two experiments were performed on 32 Wister male rats that were divided into 4 groups of 8 rats each. Each experiment was represented by 2 groups; the control group (CG) and the Spirulina group (SG). A full-thickness wound (1.5 × 1.5 cm) and burn wound (2 × 2 cm) were made on the back of each generally anaesthetized rat and the areas of wound and burn were measured on days of 0, 3, 6, 9, 12, and 15 and 0, 3, 6, 9, 12, 15, 18, and 21 post-wound and post-burn respectively. In both experiments, SP was topically applied on the backs of wounded and burned rats in Spirulina treated groups. The phases of wound granulation tissues were detected histopathologically. Immunohistochemistry was used to determine the expressions of (TGF-B1) and (VEGF). Furthermore, the relative quantification of gene expression was implemented using the (bFGF), (VEGF), (TGF-Ɓ1), and (α-SMA) as target genes. Histopathological examination revealed inflammatory cell infiltration, angiogenesis, epithelialization, and extracellular matrix deposition and wound contraction in SG as compared to CG in both experiments. Immunohistochemistry results showed a significant improvement in the VEGF and TGF-ß1 expression levels of SG in both experiments. Interestingly, SG in both experiments revealed upregulation of angiogenic genes (bFGF and VEGF) and downregulation of fibrotic genes (TGF-ß1 and α-SMA). In conclusion, our findings suggest that the topically applied Spirulina promoted wound healing. Thus, SP can be used as a biomedical application to treat various skin wounds and may reveal a potential molecular basis for future promising antifibrotic agents against scar formation.

Short-term Results of Platelet-Rich Plasma in the Treatment of Chronic Anal Fissure: Randomized Controlled Clinical Study.

BACKGROUND: Anal fissure is one of the most common benign anal disorders, and medical treatments play an important role in its management. OBJECTIVE: The purpose of this study was to investigate the short-term effects and success of platelet-rich plasma in the treatment of chronic anal fissure. DESIGN: The study is a 2 parallel group, randomized, controlled clinical trial. SETTINGS: The study was performed in 2 tertiary university hospitals. PATIENTS: Forty-four patients with chronic anal fissure were randomly assigned to platelet-rich plasma treatment or control group. Presenting symptoms and pain scores were recorded on enrollment. The control patient self-administered topical glyceryl trinitrate. Platelet-rich plasma was injected locally in the intervention group followed by self-administered glyceryl trinitrate. MAIN OUTCOME MEASURES: The primary outcome measure is a reduction in pain scores. RESULTS: On day 10 and 1 month after treatment, the mean pain score was significantly lower in the patients treated with platelet-rich plasma than in the controls (p = 0.005 and p < 0.005). By 1 month after treatment, the mean pain score declined by 5.7 points in the platelet-rich plasma-treated group compared with a 4.1 mean pain score decline in the control group (mean difference:1.6 points (95% CI, 0.3-2.9)). According to the repeated-measures analyses, pain scores decreased in both groups, but the decrease in the treatment group was statistically higher than in the control group (p < 0.001). Complete epithelialization and recovery rates were significantly higher in the platelet-rich plasma group than in controls at all follow-up times, with p values ranging from 0.034 to <0.001. The observed difference in complete epithelialization after 2 months of treatment between the platelet-rich plasma group and the control group was 56.2% with a 95% CI of 14.03% to 98.4%. LIMITATIONS: This study was limited by its small sample size, and long-term follow-up of the patients was not presented. CONCLUSIONS: Platelet-rich plasma reduced concerns and accelerated epithelialization and healing in patients with chronic anal fissures. See Video Abstract at http://links.lww.com/DCR/B461.RESULTADOS A CORTO PLAZO DEL PLASMA RICO EN PLAQUETAS EN EL TRATAMIENTO DE LA FISURA ANAL CRÓNICA: ESTUDIO CLÍNICO CONTROLADO ALEATORIZADO. ANTECEDENTES: La fisura anal es uno de los trastornos anales benignos más comunes y los tratamientos médicos juegan un papel importante en su manejo. OBJETIVO: El propósito de este estudio fue investigar los efectos a corto plazo y el éxito del plasma rico en plaquetas en el tratamiento de la fisura an33al crónica. DISEO: El estudio es un ensayo clínico controlado, aleatorizado y de dos grupos paralelos. ESCENARIO: El estudio se llevó a cabo en dos hospitales universitarios terciarios. PACIENTES: Cuarenta y cuatro pacientes con fisura anal crónica fueron asignados aleatoriamente al grupo de tratamiento con plasma rico en plaquetas o al grupo control. Los síntomas de presentación y las puntuaciones de dolor se registraron en la inscripción. Los pacientes de control se autoadministraron trinitrato de glicerilo tópico. El plasma rico en plaquetas se inyectó localmente en el grupo de intervención seguido de trinitrato de glicerilo autoadministrado. PRINCIPALES MEDIDAS DE RESULTADO: La principal medida de resultado es una reducción en las puntuaciones de dolor. RESULTADOS: El día 10 y un mes después del tratamiento, la puntuación media de dolor fue significativamente menor en los pacientes con plasma rico en plaquetas que en los controles (p = 0.005 y p <0.005, respectivamente). Un mes después del tratamiento, la puntuación media de dolor disminuyó 5.7 puntos en el grupo tratado con plasma rico en plaquetas en comparación con una disminución de la puntuación media de dolor de 4.1 en el grupo de control (diferencia media: 1.6 puntos [intervalo de confianza del 95%; 0.3-2.9] Según los análisis de medidas repetidas, las puntuaciones de dolor disminuyeron en ambos grupos, pero la disminución en el grupo de tratamiento fue estadísticamente mayor que en el grupo de control (p <0.001). Las tasas de epitelización completa y recuperación fueron significativamente más altas en los pacientes con plasma rico en plaquetas que en los controles en todos los tiempos de seguimiento, con valores de p que van desde 0.034 a <0.001. La diferencia observada en la epitelización completa después de dos meses de tratamiento entre el grupo de plasma rico en plaquetas y el grupo de control fue del 56.2% con un intervalo de confianza del 95% del 14.03% al 98.4%. LIMITACIONES: Este estudio estuvo limitado por el pequeño tamaño de la muestra y porque no se proporcionó un seguimiento a largo plazo de los pacientes. CONCLUSIONES: El plasma rico en plaquetas redujo las molestias y aceleró la epitelización y la curación en pacientes con fisuras anales crónicas. Consulte Video Resumen en http://links.lww.com/DCR/B461. (Traducción-Dr. Jorge Silva Velazco).

In-vivo wound healing activity of a novel composite sponge loaded with mucilage and lipoidal matter of Hibiscus species.

Many researches have been undergone to hasten the natural wound healing process. In this study, several Hibiscus species (leaves) were extracted with petroleum ether, methanol, and their mucilage was separated. All the tested species extracts were assessed for their viability percentage using the water-soluble tetrazolium. H.syriacus was the plant of choice to be incorporated in a new drug delivery system and evaluated for its wound healing activity. H.syriacus petroleum ether extract (PEE) showed a high percentage of palmitic and oleic acids while its mucilage demonstrated high glucosamine and galacturonic acid. It was selected to be formulated and pharmaceutically evaluated into three different composite sponges using chitosan in various ratios. Fourier-transformed infrared spectroscopy investigated the chemical interaction between the utilized sponges' ingredients. Morphological characteristics were evaluated using scanning electron microscopy. H.syriacus composite sponge of mucilage: chitosan (1:5) was loaded with three different concentrations of PEE. Medicated formulations were assessed in rat model of excision wound model. The wound healing ability was clearly proved by the clinical acceleration, histopathological examination, and modulation of correlated inflammatory parameters as tumor necrosis factor in addition to vascular endothelial growth factor suggesting a promising valuable candidate that supports the management of excision wounds using single-dose preparation.

Omega-7 oil increases telomerase activity and accelerates healing of grafted burn and donor site wounds.

This study investigated the efficacy of Omega-7 isolated from the sea buckthorn oil (Polyvit Co., Ltd, Gangar Holding, Ulaanbaatar, Mongolia) in ovine burn wound healing models. In vitro, proliferation (colony-forming rate) and migration (scratch) assays using cultured primary ovine keratinocytes were performed with or without 0.025% and 0.08% Omega-7, respectively. The colony-forming rate of keratinocytes in the Omega-7 group at 72 and 96 h were significantly higher than in the control (P < 0.05). The percentage of closure in scratch assay in the Omega-7 group was significantly higher than in the control at 17 h (P < 0.05). In vivo, efficacy of 4% Omega-7 isolated from buckthorn oil was assessed at 7 and 14 days in grafted ovine burn and donor site wounds. Telomerase activity, keratinocyte growth factor, and wound nitrotyrosine levels were measured at day 14. Grafted sites: Un-epithelialized raw surface area was significantly lower and blood flow was significantly higher in the Omega-7-treated sites than in control sites at 7 and 14 days (P < 0.05). Telomerase activity and levels of keratinocyte growth factors were significantly higher in the Omega-7-treated sites after 14 days compared to those of control (P < 0.05). The wound 3-nitrotyrosine levels were significantly reduced by Omega-7. Donor sites: the complete epithelialization time was significantly shorter and blood flow at day 7 was significantly higher in the Omega-7-treated sites compared to control sites (P < 0.05). In summary, topical application of Omega-7 accelerates healing of both grafted burn and donor site wounds. Omega-7 should be considered as a cost-efficient and effective supplement therapy for burn wound healing.

In-vivo evaluation of Alginate-Pectin hydrogel film loaded with Simvastatin for diabetic wound healing in Streptozotocin-induced diabetic rats.

Previously we developed and characterized a novel hydrogel film wound dressing containing Sodium Alginate and Pectin loaded with Simvastatin with multi-functional properties. This study investigated the in-vivo efficacy of the developed wound dressing on type I diabetic wound model. Experiments were performed on male Wistar rats for the period of 21-days. Animals developed diabetes after intraperitoneal injection (50 mg/kg) of Streptozotocin then randomly divided into different groups. On days 7, 14, and 21 of post-wounding, animals were euthanized and the wounds tissue were harvested for analysis. The wound healing rate, hematology and histological analysis, hydroxyproline assay, and Vascular Endothelial Growth Factor A measurements were noted. The results revealed that the wound dressing healed the wounded area significantly (p < 0.05) higher than the control after 21-day treatment and wound closure was ~99% without any adverse systemic reactions. Histological analysis qualitatively revealed an enhanced re-epithelialization and collagen deposition. Moreover, results also showed an improved rate of collagen synthesis and angiogenesis in the group treated with the hydrogel film loaded with Simvastatin. Thus, the present study demonstrated that developed film holds great potential for the acceleration of diabetic wound healing by its pro-angiogenic effect, faster re-epithelialization and increased collagen deposition.

Glycyrrhizin micelle as a genistein nanocarrier: Synergistically promoting corneal epithelial wound healing through blockage of the HMGB1 signaling pathway in diabetic mice.

The purpose of this study was to explore the feasibility of targeting the HMGB1 signaling pathway to treat diabetic keratopathy with a dipotassium glycyrrhizinate-based micelle ophthalmic solution encapsulating genistein (DG-Gen), and to evaluate whether these dipotassium glycyrrhizinate (DG) micelles could synergistically enhance the therapeutic effect of encapsulated genistein (Gen). An optimized DG-Gen ophthalmic solution was fabricated with a Gen/DG weight of ratio 1:15, and this formulation featured an encapsulation efficiency of 98.96 ± 0.82%, and an average particle size of 29.50 ± 2.05 nm. The DG-Gen ophthalmic solution was observed to have good in vivo ocular tolerance and excellent in vivo corneal permeation, and to remarkably improve in vitro antioxidant activity. Ocular topical application of the DG-Gen ophthalmic solution significantly prompted corneal re-epithelialization and nerve regeneration in diabetic mice, and this efficacy might be due to the inhibition of HMGB1 signaling through down-regulation of HMGB1 and its receptors RAGE and TLR4, as well as inflammatory factor interleukin (IL)-6 and IL-1ß. In conclusion, these data showed that HMGB1 signaling is a potential regulation target for the treatment of diabetic keratopathy, and novel DG-micelle formulation encapsulating active agents such as Gen could synergistically cause blockage of HMGB1 signaling to prompt diabetic corneal and nerve wound healing.

BET bromodomain inhibitors regulate keratinocyte plasticity.

Although most acute skin wounds heal rapidly, non-healing skin ulcers represent an increasing and substantial unmet medical need that urgently requires effective therapeutics. Keratinocytes resurface wounds to re-establish the epidermal barrier by transitioning to an activated, migratory state, but this ability is lost in dysfunctional chronic wounds. Small-molecule regulators of keratinocyte plasticity with the potential to reverse keratinocyte malfunction in situ could offer a novel therapeutic approach in skin wound healing. Utilizing high-throughput phenotypic screening of primary keratinocytes, we identify such small molecules, including bromodomain and extra-terminal domain (BET) protein family inhibitors (BETi). BETi induce a sustained activated, migratory state in keratinocytes in vitro, increase activation markers in human epidermis ex vivo and enhance skin wound healing in vivo. Our findings suggest potential clinical utility of BETi in promoting keratinocyte re-epithelialization of skin wounds. Importantly, this novel property of BETi is exclusively observed after transient low-dose exposure, revealing new potential for this compound class.

Carbon quantum dots-embedded electrospun antimicrobial and fluorescent scaffold for reepithelialization in albino wistar rats.

A prosthetic scaffold development using fluorescent nanofiber is reported for an enhanced reepithelialization in wistar albino rats. In this study, a novel approach was followed to construct the biocompatible fluorescent nanofiber that will be helpful to monitor the tissue regeneration process. Here, a multifunctional carbon quantum dots (CQDs)-embedded electrospun polyacrylonitrile (PAN) nanofiber was fabricated and characterized using standard laboratory techniques. The biodegradation ability was assessed by simulated body fluid thereby analyzing porosity and water absorption capacity of the material. The fluorescent scaffold was tested for cytotoxicity and antimicrobial activity using bacterial and fibroblast cells and fluorescent stability was analyzed by bioimaging of animal and bacterial cells. Tissue regeneration capability of the developed scaffold was evaluated using wistar albino rats. Unlike biomicking scaffolds, the CQDs-embedded PAN-based substrate has given dual support by enhancing reepithelialization without growth factors and acted as an antimicrobial agent to provide contamination free tissue regeneration. Scaffolds were examined by using histostaining techniques and scanning electron microscopy to observe the reepithelialization in the regenerated tissues. The novel approach for developing infection free soft tissue regeneration was found to be phenomenal in scaffold development.

Thyroxine restores severely impaired cutaneous re-epithelialisation and angiogenesis in a novel preclinical assay for studying human skin wound healing under "pathological" conditions ex vivo.

Impaired cutaneous wound healing remains a major healthcare challenge. The enormity of this challenge is compounded by the lack of preclinical human skin wound healing models that recapitulate selected key factors underlying impaired healing, namely hypoxia/poor tissue perfusion, oxidative damage, defective innervation, and hyperglycaemia. Since organ-cultured human skin already represents a denervated and impaired perfusion state, we sought to further mimic "pathological" wound healing conditions by culturing experimentally wounded, healthy full-thickness frontotemporal skin from three healthy female subjects for three days in either serum-free supplemented Williams' E medium or in unsupplemented medium under "pathological" conditions (i.e. hypoxia [5% O2], oxidative damage [10 mM H2O2], absence of insulin, excess glucose). Under these "pathological" conditions, dermal-epidermal split formation and dyskeratosis were prominent in organ-cultured human skin, and epidermal reepithelialisation was significantly impaired (p < 0.001), associated with reduced keratinocyte proliferation (p < 0.001), cytokeratin 6 expression (p < 0.001) and increased apoptosis (p < 0.001). Moreover, markers of intracutaneous angiogenesis (CD31 immunoreactivity and the number of of CD31 positive cells and CD31 positive vessel lumina) were significantly reduced. Since we had previously shown that thyroxine promotes wound healing in healthy human skin ex vivo, we tested whether this in principle also occurs under "pathological" wound healing conditions. Indeed, thyroxine administration sufficed to rescue re-epithelialisation (p < 0.001) and promoted both epidermal keratinocyte proliferation (p < 0.01) and angiogenesis in terms of CD31 immunoreactivity and CD31 positive cells under "pathological" conditions (p < 0.001) ex vivo. This demonstrates the utility of this pragmatic short-term ex vivo model, which recapitulates some key parameters of impaired human skin wound healing, for the preclinical identification of promising wound healing promoters.

A Dual-Acting Nitric Oxide Donor and Phosphodiesterase 5 Inhibitor Promotes Wound Healing in Normal Mice and Mice with Diabetes.

Chronic wounds affect a large percentage of the population worldwide and cause significant morbidity. Unfortunately, efficient compounds for the treatment of chronic wounds are yet not available. Endothelial dysfunction, which is at least in part a result of compromised nitric oxide production and concomitant reduction in cGMP levels, is a major pathologic feature of chronic wounds. Therefore, we designed and synthesized a compound with a unique dual-acting activity (TOP-N53), acting as a nitric oxide donor and phosphodiesterase 5 inhibitor, and applied it locally to full-thickness skin wounds in healthy and healing-impaired mice with diabetes. TOP-N53 promoted keratinocyte proliferation, angiogenesis, and collagen maturation in healthy mice without accelerating the wound inflammatory response or scar formation. Most importantly, it partially rescued the healing impairment of mice with genetically determined type II diabetes (db/db) by stimulating re-epithelialization and granulation tissue formation, including angiogenesis. In vitro studies with human and murine primary cells showed a positive effect of TOP-N53 on keratinocyte and fibroblast migration, keratinocyte proliferation, and endothelial cell migration and tube formation. These results demonstrate a remarkable healing-promoting activity of TOP-N53 by targeting the major resident cells in the wound tissue.

PERK Inhibition Promotes Post-angioplasty Re-endothelialization via Modulating SMC Phenotype Changes.

BACKGROUND: Drug-eluting stents impair post-angioplasty re-endothelialization thus compromising restenosis prevention while heightening thrombotic risks. We recently found that inhibition of protein kinase RNA-like endoplasmic reticulum kinase (PERK) effectively mitigated both restenosis and thrombosis in rodent models. This motivated us to determine how PERK inhibition impacts re-endothelialization. METHODS: Re-endothelialization was evaluated in endothelial-denuded rat carotid arteries after balloon angioplasty and periadventitial administration of PERK inhibitor in a hydrogel. To study whether PERK in smooth muscle cells (SMCs) regulates re-endothelialization by paracrinally influencing endothelial cells (ECs), denuded arteries exposing SMCs were lentiviral-infected to silence PERK; in vitro, the extracellular vesicles isolated from the medium of PDGF-activated, PERK-upregulating human primary SMCs were transferred to human primary ECs. RESULTS: Treatment with PERK inhibitor versus vehicle control accelerated re-endothelialization in denuded arteries. PERK-specific silencing in the denuded arterial wall (mainly SMCs) also enhanced re-endothelialization compared to scrambled shRNA control. In vitro, while medium transfer from PDGF-activated SMCs impaired EC viability and increased the mRNA levels of dysfunctional EC markers, either PERK inhibition or silencing in donor SMCs mitigated these EC changes. Furthermore, CXCL10, a paracrine cytokine detrimental to ECs, was increased by PDGF activation and decreased after PERK inhibition or silencing in SMCs. CONCLUSIONS: Attenuating PERK activity pharmacologically or genetically provides an approach to accelerating post-angioplasty re-endothelialization in rats. The mechanism may involve paracrine factors regulated by PERK in SMCs that impact neighboring ECs. This study rationalizes future development of PERK-targeted endothelium-friendly vascular interventions.

Rectal administration of carbon monoxide inhibits the development of intestinal inflammation and promotes intestinal wound healing via the activation of the Rho-kinase pathway in rats.

The inhalation of carbon monoxide (CO) gas and the administration of CO-releasing molecules were shown to inhibit the development of intestinal inflammation in a murine colitis model. However, it remains unclear whether CO promotes intestinal wound healing. Herein, we aimed to evaluate the therapeutic effects of the topical application of CO-saturated saline enemas on intestinal inflammation and elucidate the underlying mechanism. Acute colitis was induced with trinitrobenzene sulfonic acid (TNBS) in male Wistar rats. A CO-saturated solution was prepared via bubbling 50% CO gas into saline and was rectally administrated twice a day after colitis induction; rats were sacrificed 3 or 7 days after induction for the study of the acute or healing phases, respectively. The distal colon was isolated, and ulcerated lesions were measured. In vitro wound healing assays were also employed to determine the mechanism underlying rat intestinal epithelial cell restitution after CO treatment. CO solution rectal administration ameliorated acute TNBS-induced colonic ulceration and accelerated ulcer healing without elevating serum CO levels. The increase in thiobarbituric acid-reactive substances and myeloperoxidase activity after induction of acute TNBS colitis was also significantly inhibited after CO treatment. Moreover, the wound healing assays revealed that the CO-saturated medium enhanced rat intestinal epithelial cell migration via the activation of Rho-kinase. In addition, the activation of Rho-kinase in response to CO treatment was confirmed in the inflamed colonic tissue. Therefore, the rectal administration of a CO-saturated solution protects the intestinal mucosa from inflammation and accelerates colonic ulcer healing through enhanced epithelial cell restitution. CO may thus represent a novel therapeutic agent for the treatment of inflammatory bowel disease.