Porcine-derived collagen peptides promote re-epithelialisation through activation of integrin signalling.

Chronic non-healing cutaneous wounds represent a major burden to patients and healthcare providers worldwide, emphasising the continued unmet need for credible and efficacious therapeutic approaches for wound healing. We have recently shown the potential for collagen peptides to promote proliferation and migration during cutaneous wound healing. In the present study, we demonstrate that the application of porcine-derived collagen peptides significantly increases keratinocyte and dermal fibroblast expression of integrin α2ß1 and activation of an extracellular signal-related kinase (ERK)-focal adhesion kinase (FAK) signalling cascade during wound closure in vitro. SiRNA-mediated knockdown of integrin ß1 impaired porcine-derived collagen peptide-induced wound closure and activation of ERK-FAK signalling in keratinocytes but did not impair ERK or FAK signalling in dermal fibroblasts, implying the activation of differing downstream signalling pathways. Studies in ex vivo human 3D skin equivalents subjected to punch biopsy-induced wounding confirmed the ability of porcine-derived collagen peptides to promote wound closure by enhancing re-epithelialisation. Collectively, these data highlight the translational and clinical potential for porcine-derived collagen peptides as a viable therapeutic approach to promote re-epithelialisation of superficial cutaneous wounds.

Morroniside promotes skin wound re-epithelialization by facilitating epidermal stem cell proliferation through GLP-1R-mediated upregulation of ß-catenin expression.

Epidermal stem cells (EpSCs) play a vital role in skin wound healing through re-epithelialization. Identifying chemicals that can promote EpSC proliferation is helpful for treating skin wounds. This study investigates the effect of morroniside on cutaneous wound healing in mice and explores the underlying mechanisms. Application of 10‒50 µg/mL of morroniside to the skin wound promotes wound healing in mice. In vitro studies demonstrate that morroniside stimulates the proliferation of mouse and human EpSCs in a time- and dose-dependent manner. Mechanistic studies reveal that morroniside promotes the proliferation of EpSCs by facilitating the cell cycle transition from the G1 to S phase. Morroniside increases the expression of ß-catenin via the glucagon-like peptide-1 receptor (GLP-1R)-mediated PKA, PKA/PI3K/AKT and PKA/ERK signaling pathways, resulting in an increase in cyclin D1 and cyclin E1 expression, either directly or by upregulating c-Myc expression. This process ultimately leads to EpSC proliferation. Administration of morroniside to mouse skin wounds increases the phosphorylation of AKT and ERK, the expressions of ß-catenin, c-Myc, cyclin D1, and cyclin E1, as well as the proliferation of EpSCs, in periwound skin tissue, and accelerates wound re-epithelialization. These effects of morroniside are mediated by the GLP-1R. Overall, these results indicate that morroniside promotes skin wound healing by stimulating the proliferation of EpSCs via increasing ß-catenin expression and subsequently upregulating c-Myc, cyclin D1, and cyclin E1 expressions through GLP-1R signaling pathways. Morroniside has clinical potential for treating skin wounds.

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.

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).

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.

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.

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).

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.

Mutation of Arginine 264 on ERα (Estrogen Receptor Alpha) Selectively Abrogates the Rapid Signaling of Estradiol in the Endothelium Without Altering Fertility.

OBJECTIVE: ERα (estrogen receptor alpha) exerts nuclear genomic actions and also rapid membrane-initiated steroid signaling. The mutation of the cysteine 451 into alanine in vivo has recently revealed the key role of this ERα palmitoylation site on some vasculoprotective actions of 17ß-estradiol (E2) and fertility. Here, we studied the in vivo role of the arginine 260 of ERα which has also been described to be involved in its E2-induced rapid signaling with PI-3K (phosphoinositide 3-kinase) as well as G protein in cultured cell lines. Approach and Results: We generated a mouse model harboring a point mutation of the murine counterpart of this arginine into alanine (R264A-ERα). In contrast to the C451A-ERα, the R264A-ERα females are fertile with standard hormonal serum levels and normal control of hypothalamus-pituitary ovarian axis. Although R264A-ERα protein abundance was normal, the well-described membrane ERα-dependent actions of estradiol, such as the rapid dilation of mesenteric arteries and the acceleration of endothelial repair of carotid, were abrogated in R264A-ERα mice. In striking contrast, E2-regulated gene expression was highly preserved in the uterus and the aorta, revealing intact nuclear/genomic actions in response to E2. Consistently, 2 recognized nuclear ERα-dependent actions of E2, namely atheroma prevention and flow-mediated arterial remodeling were totally preserved. CONCLUSIONS: These data underline the exquisite role of arginine 264 of ERα for endothelial membrane-initiated steroid signaling effects of E2 but not for nuclear/genomic actions. This provides the first model of fertile mouse with no overt endocrine abnormalities with specific loss-of-function of rapid ERα signaling in vascular functions.

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.

The effect of tadalafil on reepithelialization and scarring of partial thickness porcine burns.

Burn conversion from second to third degree is common leading to delayed healing and scarring. We hypothesized that tadalafil, a phosphodiesterase 5 inhibitor (PDE5I) that results in vasodilation, would reduce burn conversion leading to faster reepithelialization and less scarring of partial thickness porcine burns. We conducted a prospective, randomized, controlled, animal experiment using six female pigs (25-30 kg). We created 20 standardized partial thickness burns on each of the animals with an aluminum bar preheated to 80 °C and applied for 20 seconds to the pigs' dorsum. Three animals each were randomized to oral tadalafil 2.5 mg or control vehicle once daily for 1 week. Main outcomes were time to reepithelialization and depth of scarring at 28 days. A sample of 60 burns in each treatment group had 80% power to detect a 2-day difference in time to reepithelialization. Mean (95% CI) time to reepithelialization in burns treated with tadalafil and control were 14.9 (14.1-15.7) vs. 19.7 (18.2-21.3) days, respectively; mean difference 4.8 (3.1-6.6) days. After controlling for pig and within pig differences, mean time to reepithelialization was 6.5 (3.7-9.3) days shorter in burns treated with tadalafil compared with controls. Mean (95% CI) scar depth in burns treated with tadalafil and control were 2.7 (2.3-3.1) vs. 3.7 (3.1-4.2) mm. respectively, mean difference 1 (0.3-1.7) mm. After controlling for pig and within pig differences, scar depth in tadalafil-treated burns was 1.5 (0.7-2.3) mm lower compared with controls. We conclude that once daily oral tadalafil shortened time to reepithelialization and reduced scarring in a partial thickness porcine burns model.

Akermanite bioceramic enhances wound healing with accelerated reepithelialization by promoting proliferation, migration, and stemness of epidermal cells.

Reepithelialization is an important step of wound healing, which is mainly completed by proliferation and migration of epidermal cells. Akermanite is a Ca-, Mg-, and Si-containing bioceramic. This study evaluated the effects of Akermanite on wound healing and investigated the mechanisms. Using scald burn mice models, we demonstrated that local Akermanite treatment significantly accelerated wound healing by increasing reepithelialization and the stemness of epidermal cells. Epidermal cells were cultured in medium containing Akermanite extracts to explore the cellular mechanism of reepithelialization. Akermanite promoted the cell proliferation and migration, maintaining more cells in the S and G2 /M phases of the cell cycle. An additional study showed that Akermanite enhanced the expressions of integrinß1, Lgr4, Lgr5, and Lgr6, which are specific molecular markers of epidermal stem cells, accompanied by the activation of the Wnt/ß-catenin pathway. These results suggested that Akermanite accelerated reepithelialization by increasing the proliferation, migration, and stemness of epidermal cells in a manner related to the Wnt/ß-catenin pathway, which might contribute, at least partially, to accelerated wound healing by Akermanite therapy.

Fibroblast Proliferation and Migration in Wound Healing by Phytochemicals: Evidence for a Novel Synergic Outcome.

Wound-healing is a dynamic skin reparative process that results in a sequence of events, including inflammation, proliferation, and migration of different cell types as fibroblasts. Fibroblasts play a crucial role in repairing processes, from the late inflammatory phase until the fully final epithelization of the injured tissue. Within this context, identifying tools able to implement cell proliferation and migration could improve tissue regeneration. Recently, plants species from all over the world are coming out as novel tools for therapeutic applications thanks to their phytochemicals, which have antioxidant properties and can promote wound healing. In this paper, we aimed at investigating antioxidant activity of waste extracts from different medicinal plants, endemic of the Mediterranean area, on fibroblast proliferation and wound healing. We determined the amount of total phenols and anti-oxidant activity by ABTS assay. We then evaluated the cytotoxicity of the compounds and the proliferative capabilities of fibroblasts by scratch assay. Our results showed that waste extracts retain antioxidant and regenerative properties, inducing tissue re-establishment after environmental stress exposure. Taken together, our findings suggest that waste material could be used in the future also in combinations to stimulate wound healing processes and antioxidant responses in damaged skin.

Effect of epidermal growth factor ointment on persistent epithelial defects of the cornea.

BACKGROUND: Healthy corneal epithelium acts as a barrier against damage to the deeper structures in the eye. Failure in the mechanisms of corneal epithelization can lead to persistent epithelial defects of the cornea (PEDs) and can compromise its function. Epidermal growth factor (EGF) promotes the proliferation, migration, and differentiation of epithelial cells, endothelial cells, and fibroblasts during wound healing and may be beneficial in treating patients with PEDs. We, therefore, investigated the effect of EGF ointment on patients with PEDs. METHODS: Fifteen patients with PEDs refractory to conventional treatment were treated twice a day with EGF ointment. Patient demographics and comorbidities were noted. The epithelial healing time was determined along with the primary outcome measures in the areas of the epithelial defects, visual acuity, visual analog scale (VAS) scores, and esthesiometer scores 1 month and 2 months after treatment. RESULTS: Five eyes of herpetic keratitis (33.3%), 3 eyes of dry eye disease (20.0%), 3 eyes of bacterial keratitis (20.0%), 2 eyes of limbal stem cell deficiency (13.3%), 1 eye of diabetic neurotrophic keratitis (6.7%), and 1 eye of filamentary keratitis (6.7%) were associated with PEDs, respectively. Two months following treatment with EGF ointment, there was a reduction in the area of the epithelial defects (5.7 ± 3.9 to 0.1 ± 0.3 mm2) as well as a significant improvement in best-corrected visual acuity (0.9 ± 0.8 to 0.6 ± 0.5 LogMAR) and VAS scores (4.5 ± 1.2 to 2.5 ± 0.7) in 12 eyes (80%). Among these cases, the mean epithelial healing time was 5.5 ± 1.8 weeks. Amniotic membrane transplantation was performed on the remaining 3 (20.0%) patients that did not respond to EGF treatment. CONCLUSIONS: EGF ointment could reduce symptoms and promotes corneal epithelialization of refractory PEDs. It may, therefore, be well-tolerated and a potentially beneficial addition in the management of refractory PEDs.

Use of Topical Timolol Maleate as Re-Epithelialization Agent for Treatment of Recalcitrant Wounds of Varying Etiologies.

Background: Chronic wounds remain a challenge for the clinician and healthcare system. It is therefore vital for additional therapies that target steps involved in wound recalcitrance. Recently, topical timolol has shown promising results for use in wound healing. Objective: The goal of this study was to assess timolol's effectiveness in healing wounds of varying etiologies. Methods: This multi-center series took place from 2016¬­2019 at the wound healing centers at the University of Miami Health System and the Veterans Affairs Northern California Healthcare. We identified all wound patients who received treatment with topical timolol maleate 0.5% for at least 4 weeks after failing previous treatments. Timolol drops at a dose of 1 drop per cm2 of wound area were instilled with dressing changes twice a day, once a day, every other day, or continuous application. Once they began the study, they stopped all concurrent therapies aside from standard of care. Healing outcomes were classified into 3 categories: healed, defined as complete re-epithelialization of the wound and closure, improved, defined as decreasing wound size area (WSA), and worsening, defined as increasing WSA. Results: We identified 39 patients, 32 males and 7 females that had a total of 55 chronic wounds of varying etiologies. Thirty-four of the wounds had completely healed, 15 wounds improved in WSA, 4 wounds were unchanged in WSA, and 2 wounds worsened in WSA. Conclusions: In line with our previous experience, we found topical timolol to be a safe, cost-effective, and efficacious treatment for recalcitrant wounds of varying etiologies.

Epidermal Regeneration Induced by Comfrey Extract: A Study by Light and Electron Microscopy.

INTRODUCTION: An accelerated healing of superficial wounds was demonstrated in clinical trials with a topical comfrey preparation (Symphytum × uplandicum Nyman). The effect has previously not been examined in skin models. METHODS: An established in vitro model of epidermal cells with the typical strata was used for the observation of effects of applied substances on skin regeneration. Damage corresponding to a typical abrasion was created on day 1 by punching an opening into the epidermal fine structure down to the stratum basale. Samples were either untreated (controls) or exposed to comfrey cream on days 2, 3, 5, and 6. Tissue samples were taken for light and electron microscopy on days 1, 4, and 7. RESULTS AND CONCLUSIONS: Application of comfrey cream led to a quicker regeneration of skin cells and to an earlier differentiation of the cells towards a normal fine structure with a visible distinction of epidermal strata, keratin, and corneocyte formation within 4-7 days. The study covered the early days of skin regeneration and confirms the benefits observed in published clinical trials and non-interventional studies in patients with abrasions.

The treatment of paediatric burns with concentrated surfactant gel technology: a case series.

OBJECTIVE: To assess the safety and efficacy of a surfactant-based technology for the management of burns. METHOD: In a retrospective review, paediatric patients with different types of burns were treated with the gel technology. In some patients, the treatment was combined with a topical antimicrobial agent. Primary objectives of the review were the assessment of healing, healing times and ease of use of the material. RESULTS: The wounds of 15 paediatric patients with different types of burns, particularly with regard to depth and anatomical location, were evaluated using a retrospective chart review. It was found that the surfactant gel technology, with or without the topical antimicrobial agent, assisted in autolytic debridement, and that time to re-epithelialisation was short and within the range of those obtained with other established treatments. CONCLUSION: The number of patients and wounds in this evaluation is small but the study indicates that the gel technology provides a safe and effective way to treat smaller burns in paediatric patients.

Carbonic Anhydrase VI in Skin Wound Healing Study on Car6 Knockout Mice.

Carbonic anhydrases (CAs) contribute to tumor cell migration by generating an acidic environment through the conversion of carbon dioxide to bicarbonate and a proton. CA VI is secreted to milk and saliva, and it could contribute to wound closure, as a potential trophic factor, in animals that typically lick their wounds. Our aim was to investigate whether human CA VI improves skin-wound healing in full-thickness skin-wound models. The effect was studied in Car6 -/- knockout mice and wild type littermates. Half of both mice strains were given topically administered, milk-derived CA VI after wounding and eight hours later. The amount of topically given CA VI exceeded the predicted amount of natural saliva-delivered CA VI. The healing was followed for seven days and studied from photographs and histological sections. Our results showed no significant differences between the treatment groups in wound closure, re-epithelization, or granulation tissue formation, nor did the Car6 genotype affect the healing. Our results demonstrate that CA VI does not play a major role in skin-wound healing and also suggest that saliva-derived CA VI is not responsible for the licking-associated improved wound healing in animals.

Effects and Characterization of Some Topical Ointments Based on Vegetal Extracts on Incision, Excision, and Thermal Wound Models.

The present paper aims to formulate and characterize four phytotherapeutic ointments based on Hippophae fructus, Calendulae flos, Bardanae folium, and Millefolii herba, which are included in a novel ointment base. In order to investigate the healing properties of the ointments, in vivo experimental wound models of linear incision, circular excision, and thermal burn were performed on Wistar rats. Topical treatment was performed daily for 21 days. Determination of the wound contraction rate (WCR), the period of reepithelization, and histopathological examination were achieved. Additionally, for the tested ointments, oscillatory and rotational rheological tests were carried out, and for the extracts, HPLC analysis was performed. The results demonstrate that the tested novel ointments are safe for use and the most effective ointment proved to be the one based on Arctium lappa, followed by that of Calendulae flos.

Use of concentrate growth factors gel or membrane in chronic wound healing: Description of 18 cases.

Treating chronic skin wounds in patients with diabetes, bed sores, or stasis dermatitis is typically a time-consuming and costly process, and the outcome is not always promising. Concentrated growth factor (CGF) obtained from the autologous venous blood of patients via fractional centrifugation is employed for producing a CGF gel or membrane that can be applied to expedite self-regeneration of skin wounds. In this case report, we presented the results from 18 patients with chronic skin wounds treated with a CGF gel or membrane produced from autologous venous blood. Noticeable granulation tissue and regenerated epidermal coverage were observed in 16 patients who received CGF treatment over various time courses, thereby demonstrating the significant therapeutic effects of CGF treatment in overall wound healing. The other two patients with stasis ulcers in their calves failed to respond to the treatment because of the comorbidity of iliac vein thrombosis. In addition, by culturing HaCaT keratinocytes using CGF membrane as the foundation, we observed that HaCaT cells attached to the CGF membrane migrated and proliferated to form an epithelium-like structure. Comprehensively, the clinical results infer that CGF gel can expedite the regeneration of the soft tissue at the wound, whereas CGF membrane may facilitate its marginal re-epithelialisation. The combination of the two can promote autologous regeneration of both deep and superficial wounds effectively and safely.