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Introduction: Corneal ulcers are common lesions in both human and veterinary medicine. However, only a few studies have evaluated the efficacy of cross-linked hyaluronic acid (X-HA) eye drops on corneal wound healing. To our knowledge, this is the first study to demonstrate and compare the efficacy of amniotic membrane extract eye drops (AMEED) and X-HA for corneal wound healing in rats. Material and methods: A total of 15 male Wistar rats (30 eyes) were used in this study. Then, 10 eyes were treated with X-HA, AMEED, or 0.9% saline. After general and topical anesthesia, a superficial corneal ulcer was created using a corneal trephine. The defect was further polished with a diamond burr. Three groups of 10 eyes each were treated with either one drop of 0.75% X-HA or AMEED or 0.9% saline (control), administered every 12 h for a duration of 72 h. The median epithelial defect area (MEDA), expressed as a percentage of the total corneal surface, was measured at 0, 12, 24, 36, 48, and 72 h. Re-epithelization time scores were also evaluated. The Kruskal-Wallis test was used to compare median times for re-epithelization and histopathologic scores between groups, while the Friedman test (for paired data) was employed to compare results from the serial analysis of MEDA and vascularization scores between groups. Results: MEDA was not significantly different between X-HA and AMEED. However, MEDA was significantly smaller in the X-HA group compared to the control group at 36 h (2.73 interquartile range (IQR) 5.52% x 9.95 IQR 9.10%, P=0.024) and 48 h (0.00 IQR 0.26% x 6.30 IQR 8.54%, P=0.030). The overall time for re-epithelization was significantly lower in the X-HA group (3.00 IQR 3.00) compared to the AMEED (6.5 IQR 3.00) and control (7.00 IQR 1.00) groups (P=0.035). Vascularization, hydropic degeneration, and epithelial-stromal separation were significantly less observed in samples in the X-HA-treated compared to samples in the AMEED- and saline-treated groups. Significantly more corneal epithelium cells were labeled for caspase3 in samples from the AMEED- and saline-treated groups compared to those from the X-HA-treated group. Discussion: Topical X-HA has been shown to accelerate corneal epithelial healing. AMEED did not decrease corneal re-epithelialization time. X-HA may also potentially be used as an adjunct therapy for treating corneal ulcers in clinical situations.

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There are several reasons for skin damage, including genetic factors, disorders, acute trauma, hard-to-heal wounds, or surgical interventions. Whatever the cause, wounds have a substantial impact on people who experience them, their caregivers and the healthcare system. Advanced wound care products have been researched and developed, providing an opportunity for faster and more complete healing. Tissue engineering (TE) is a promising strategy that can overcome limitations when choosing a graft for a wound. Amniotic membrane is a highly abundant, readily available, and inexpensive biological tissue that does not raise ethical concerns, with many applications in different fields of TE and regenerative medicine. It has attractive physical characteristics, such as elasticity, rigidity and mechanical strength, among others. The effects can also be potentiated by association with other substances, such as hyaluronic acid and growth factors. This paper describes new perspectives involving the use of amniotic membranes.

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Macular holes (MHs), including atraumatic idiopathic and refractory MHs, affect central vision acuity due to full-thickness defects in the retinal tissue. The existing controversy regarding the pathophysiology and management of MHs has significantly improved with the implementation of internal limiting membrane (ILM) surgical techniques and improved MH closure rates. Thus, to determine the effect of ILM techniques on large idiopathic and refractory MH management, the present study systematically reviewed 5910 original research articles extracted from online literature databases, including PubMed, Cochrane, Google Scholar, and Embase, following the PRISMA guidelines. The primary outcome measures were MH closure rate and postoperative visual acuity. A total of 23 randomized controlled trials (RCTs) with adequate patient information and information on the effect of ILM peeling, inverted ILM flaps, autologous retinal transplantation (ART), and ILM insertion techniques on large idiopathic and refractory MH patients were retrieved and analyzed using RevMan software (version 5.3) provided by the Cochrane Collaboration. Statistical risk of bias analysis was also conducted on the selected sources using RoB2, which showed a low risk of bias in the included studies. A meta-analysis indicated that the inverted ILM flap technique had a significantly greater MH closure rate for primary MH than the other treatment methods (OR = 3. 22, 95% CI 1.34-7.43; p = 0.01). Furthermore, the findings showed that the inverted ILM flap group had significantly better postoperative visual acuity than did the other treatment options for patients with idiopathic MH (WMD = - 0.13; 95% CI = 0.22-0.09; p = 0.0002). The ILM peeling technique had the second highest statistical significance for MH closure rates in patients with idiopathic MH (OR = 2. 72, 95% CI: 1.26-6.32; p = 0.016). In refractory MHs, autologous retinal transplant (ART) and multilayer ILM plug (MIP) techniques improve the closure rate and visual function; human amniotic membrane grafting (hAMG) provides a high degree of anatomical outcomes but disappointing visual results. This study demonstrated the reliability and effectiveness of ILM techniques in improving the functional and anatomical outcomes of large idiopathic and refractory MH surgery. These findings will help clinicians choose the appropriate treatment technique for patients with idiopathic and refractory MH.

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Introducción: El amniocele es una hernia del saco amniótico a través de un defecto en la pared del útero, el cual puede deberse a ruptura uterina, secundario a daños preexistentes, anomalías uterinas o en un útero sin cicatrices. Caso clínico: Presentamos el caso de una paciente de 37 años, con antecedente de dos partos por cesárea, a quien en la semana 25,5 de embarazo se le diagnostica por ecografía amniocele en la pared anterior de útero contenido por la vejiga, además de signos ecográficos de acretismo placentario. La posterior realización de resonancia magnética confirma el diagnóstico. Se realiza manejo expectante con estancia continua intrahospitalaria estricta. Resolución obstétrica a las 34 semanas por cesárea, con extracción fetal por fondo uterino sin complicaciones, con posterior realización de histerectomía con placenta in situ. Conclusiones: Este reporte de caso ilustra la importancia de la identificación temprana de esta condición por ser una complicación infrecuente, pero de grave pronóstico fetomaterno en ausencia de atención inmediata.

Introduction: Amniocele is a hernia of the amniotic sac through a defect in the uterine wall, which can be caused by uterine rupture secondary to preexisting damage, uterine anomalies, or a scarless uterus. Case report: We present a case of a 37-year-old patient with a history of two previous cesarean deliveries. At 25.5 weeks of gestation, the diagnosis of amniocele in the anterior uterine wall, contained by the bladder, along with ultrasound signs of placenta accreta, was confirmed through ultrasound. Subsequent magnetic resonance imaging further confirmed the diagnosis. Expectant management with strict continuous intrahospital stay was implemented. Obstetric resolution was achieved at 34 weeks through cesarean delivery, with uncomplicated fetal extraction through the uterine fundus. Subsequently, a hysterectomy was performed with the placenta left in situ. Conclusions: This case report illustrates the importance of early identification of this condition due to its infrequent but serious feto-maternal prognosis in the absence of immediate attention.

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BACKGROUND: Diabetic foot ulcers (DFUs) constitute a complication that occurs in 19% to 34% of patients with diabetes mellitus (DM). The aim of this study is to describe median days to healing, average velocity of wound closure, and percentage of wound surface closed at 3, 6, and 12 weeks through the use of homogenized and lyophilized amniotic membrane (hAMpe) dressings for the treatment of DFUs in ambulatory patients. METHODS: An observational, descriptive, longitudinal study was performed. Patients presenting with granulation-based DFU, after proper debridement, were included from August 19, 2021, until July 14, 2023. hAMpe dressings placed every 3 days were used for the treatment of these ulcers. RESULTS: Sixteen patients were included with a mean age of 52.38 (8.07) years. The analyzed lesions were postsurgical ulcers in 15 of the 16 included patients. Median ulcer size was 19.5 cm2 (6.12-36). The median ABI was 1.10 (1-1.14). The median days to healing was 96 (71-170). The median percentage closure of the wound at 3 weeks was 41% (28.9%-55.3%), at 6 weeks it was 68.2% (48.6%-74.2%), and at 12 weeks it was 100% (81%-100%). The average velocity closure was 1.04% per day (95% CI 0.71%-1.31%). It was higher during the closure of the first 50% of the ulcer, 2.12% per day (95% CI 0.16%-4.09%), and decreased from 50% to 25% of the ulcer size to 0.67% per day (95% CI 0.23%-1.10%) and from 25% to closure to 0.47% per day (95% CI 0.14%-0.80%), P < .001. CONCLUSION: These results are difficult to compare to other studies given the higher surface area of the ulcers included in our sample. The development of hAMpe dressings enables patients to apply them without requiring assistance from health care teams and was not associated with any recognized complications.

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Human amniotic membrane (hAM) is an important biomaterial for Tissue Engineering, due to its great regenerative properties and potential use as a scaffold. The most used procedure to sterilize biomaterials is gamma-irradiation, but this method can affect several properties, causing damage to the structure and reducing the growth factors. The present work evaluated the efficiency of a new method based on ozonated dynamic water for hAM sterilization. HAM fragments were experimentally contaminated with Staphylococcus aureus, Escherichia coli, Candida albicans, Staphylococcus epidermidis, and Clostridium sporogenes (106 CFU/mL) and submitted to sterilization process for 5, 10 and 15 min. The analyses did not reveal microbial activity after 10 min for S. aureus and C. sporogenes and after 15 min for E. coli and S. epidermidis. The microbial activity of C. albicans was reduced with the exposure time increase, but the evaluated time was insufficient for complete sterilization. The depyrogenation process was investigated for different ozonation times (15, 20, 25, 30, and 35 min) to evaluate the ozone sterilization potential and presented promising results after 35 min. The ozone effect on hAM structure was evaluated by histological analysis. A decrease in epithelium average thickness was observed with the exposure time increase. Furthermore, some damage in the epithelium was observed when hAM was exposed for 10 and 15 min. It can indicate that ozone, besides being effective in sterilization, could promote the hAM sample's de-epithelization, becoming a possible new method for removing the epithelial layer to use hAM as a scaffold.

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ABSTRACT Purpose: Wet bio-amniotic membrane plugging combined with transplantation is a novel option that combined amniotic membrane plugging with amniotic membrane transplantation for the treatment of small corneal perforations. This study aimed to evaluate the efficacy of wet bio-amniotic membrane plugging in the treatment of small corneal perforations and compared it with that of the penetrating keratoplasty procedure. Methods: Forty patients (41 eyes) with small corneal perforations <3 mm in diameter treated at our hospital between July 2018 and January 2021 were retrospectively included. Among them, 21 eyes were treated with wet bio-amniotic membrane plugging (wet bio-amniotic membrane plugging group), and 20 eyes were treated with penetrating keratoplasty procedure (penetrating keratoplasty procedure group). The best-corrected visual acuity, anterior chamber formation, corneal thickness, primary disease control, postoperative complications, and graft survival rate were assessed. Results: No significant difference in baseline characteristics was found between the wet bio-amniotic membrane plugging and penetrating keratoplasty procedure groups (p>0.05). The postoperative control rates of primary diseases in the wet bio-amniotic membrane plugging and penetrating keratoplasty procedure groups were 95.2% and 90.0%, respectively (p=0.481). Visual acuity was improved 6 months after the operation in the wet bio-amniotic membrane plugging group and was improved at postoperative 1 month in the penetrating keratoplasty procedure group. The formation time of the anterior chamber in the wet bio-amniotic membrane plugging group was significantly shorter than that in the penetrating keratoplasty procedure group (p=0.023). The corneal thickness of the two groups significantly increased 12 months after the operation; however, the degree of thickening in the penetrating keratoplasty procedure group was higher than that in the wet bio-amniotic membrane plugging group (p<0.001). During the follow-up, postoperative complications were not different between the two groups (p>0.999). Conclusion: The results suggest that wet bio-amniotic membrane plugging is effective and safe in the treatment of small corneal perforations. Thus, it can be used as an emergency treatment alternative to penetrating keratoplasty procedure for small corneal perforations.

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Los procedimientos endodónticos regenerativos (REPs) representan una evolución significativa en el campo de la endodoncia, buscando no sólo tratar la infección o lesión presente en el diente, sino tam-bién promover la regeneración de los tejidos denta-rios afectados. El presente caso clínico muestra un incisivo lateral superior izquierdo con apexogénesis incompleta y diagnóstico de absceso alveolar crónico reagudizado en una paciente de 22 años, en el que se aplicó un procedimiento de endodoncia regenerativa (REPs). La estrategia terapéutica elegida se basó en los principios de ingeniería tisular, incorporando la novedosa aplicación de la membrana amniótica hu-mana liofilizada esterilizada como andamio bioactivo intraconducto. Las evaluaciones clínicas, radiográ-ficas y tomográficas a corto, mediano y largo plazo revelaron el éxito de la terapia. La resolución exitosa mostró en los controles a la pieza dentaria asintomá-tica, con una notable remisión de la patología apical, aumento de la longitud radicular y disminución del calibre apical. Se ha podido destacar la eficacia de los REPs, con una exitosa aplicabilidad de la membra-na amniótica como andamio innovador (AU)

Regenerative endodontic procedures (REPs) represent a significant evolution in the field of endodontics, aiming not only to address the infection or injury within the tooth, but also to promote the regeneration of the affected dental tissues. In this clinical case, an upper left lateral incisor with incomplete apexogenesis and diagnosis of acute exacerbation of a chronic periapical lesion in a 22-year-old patient is presented. A regenerative endodontic procedure (REPs) was applied. The chosen therapeutic strategy was based on tissue engineering principles, incorporating the innovative use of sterilized lyophilized human amniotic membrane as an intraconduct bioactive scaffold. Clinical, radiographic, and tomographic assessments at short, medium, and long-term follow-up revealed the success of the therapy. Successful resolution demonstrated an asymptomatic tooth in the follow-up, with a notable resolution of apical pathology, increased root length, and decreased apical caliber. The effectiveness of REPs has been highlighted, demonstrating the successful applicability of amniotic membrane as an innovative scaffold (AU)

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Las quemaduras son un problema de interés en salud pública ya que generan un alto índice de morbimortalidad a nivel mundial, las quemaduras térmicas son las más prevalentes y pueden alterar la integridad anatómica, funcional y estética de la piel, aspectos fundamentales para la autoestima del paciente y su capacidad para reintegrarse a la sociedad. Al revisar la literatura sobre el tratamiento de estas afecciones encontramos diversos tratamientos, entre ellos el uso de membrana amniótica humana, la cual ha tenido un impacto importante en el manejo de quemaduras al funcionar como andamio biológico con cualidades regenerativas y antiinflamatorias. El presente artículo tiene como objetivo sintetizar la información actual que describe las aplicaciones de membranas amnióticas humanas en quemaduras, realizamos una revisión exploratoria sistemática de la literatura desde 2010 hasta 2021.

Burns are a problem of interest in public health since they generate a high rate of morbidity and mortality worldwide, thermal burns are the most prevalent and can alter the anatomical, functional and aesthetic integrity of the skin, fundamental aspects for the patient's self-esteem and their ability to reintegrate into society. At review literature about the treatment of these conditions, we find various treatments, including the use of human amniotic membrane, which has had a significant impact on burn management by functioning as a biological scaffold with regenerative and anti-inflammatory qualities. The present article aims to synthesize the current information that describes the applications of human amniotic membranes in burns. We carry out a systematic exploratory review of the literature from 2010 to 2021.

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The aim of this study was to report a case with the use of amniotic membrane transplant and deep anterior keratoplasty in a patient with bilateral Acanthamoeba infectious keratitis as a treatment. A 20-year-old male presented with bilateral Acanthamoeba keratitis (AK) who was initially diagnosed with herpetic keratitis receiving full antiviral and corticosteroid topical treatment without any improvement. Corneal biopsy was performed to confirm the suspected diagnosis, and Acanthamoeba stromal cysts were identified in the sample. Treatment was initiated with 0.02% chlorhexidine, 0.1% propamidine isethionate, neomycin, and tropicamide/phenylephrine. Symptoms and clinical improvement were achieved between the 8th and 10th weeks, so corticosteroids were initiated. Treatment was continued until we observed a poor response in the left eye; therefore, an epithelial scraping and amniotic membrane placement were performed. Lately, the right eye underwent a deep anterior lamellar keratoplasty. A challenging case of bilateral AK managed with topical medications, amniotic membrane, and corneal keratoplasty. The earlier the disease is diagnosed, the better the outcome. If the diagnosis is delayed, the amoebas have penetrated deep into the corneal stroma, and successful therapy becomes difficult. A surgical option can be an early solution with a good prognosis for these cases.

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Wound healing is a complex process of repair that involves the interaction between different cell types and involves coordinated interactions between intracellular and extracellular signaling. Bone Marrow Mesenchymal Stem Cells (BMSCs) based and acellular amniotic membrane (AM) therapeutic strategies with the potential for treatment and regeneration of tissue. We aimed to evaluate the involvement of paracrine effects in tissue repair after the flap skin lesion rat model. In the full-thickness flap skin experiment of forty Wistar rats: A total of 40 male Wistar rats were randomized into four groups: group I: control (C; n = 10), with full-thickness lesions on the back, without (BMSCs) or AM (n = 10); group II: injected (BMSCs; n = 10); group III: covered by AM; group IV-injected (AM + BMSCs; n = 10). Cytokine levels, IL-1, and IL-10 assay kits, superoxide dismutase (SOD), glutathione reductase (GRs) and carbonyl activity levels were measured by ELISA 28th day, and TGF-ß was evaluated by immunohistochemical, the expression collagen expression was evaluated by Picrosirius staining. Our results showed that the IL-1 interleukin was higher in the control group, and the IL-10 presented a higher mean when compared to the control group. The groups with BMSCs and AM showed the lowest expression levels of TGF-ß. SOD, GRs, and carbonyl activity analysis showed a predominance in groups that received treatment from 80%. The collagen fiber type I was predominant in all groups; however, the AM + BMSCs group obtained a higher average when compared to the control group. Our findings suggest that the AM+ BMSCs promote skin wound healing, probably owing to their paracrine effect attributed to the promotion of new collagen for tissue repair.

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Amniotic membrane (AM) has been widely used as a biological dressing for many pathologies and illnesses worldwide, and products derived from this tissue have been commercially available in several countries. In Brazil, regulatory agencies have recently authorized its clinical use as a non-experimental therapy for burns, diabetic and venous stasis ulcers, and intrauterine adhesions. In this study, we present our pathway through validating the first available service in the country of AM cryopreservation, with a protocol for long-term storage in high-efficiency nitrogen cryogenic freezers and a specific way of packing the tissue for optimal clinical handling and efficient storage space utilization while preserving live cells and the tissue's biological properties. Using gauze as support, cryoprotectant dimethyl sulfoxide and product presentation as a multilayer roll exhibited the best cell viability results and maintained the tissue integrity and presence of stem/progenitor cells. Essential proteins involved in tissue regeneration and immune and antimicrobial control were detected from the secretome of cryopreserved tissue similar to fresh tissue. Furthermore, immunogenic markers, such as human leukocyte antigens, were detected at very low levels in the tissue, confirming their low immunogenicity. Finally, we demonstrate that the tissue can be kept under refrigerated conditions for up to 7 d for further use, maintaining sterility and considerable cell viability. Our cryopreservation and storage protocol kept the AM viable for at least 20 months. In conclusion, this study enabled us to determine a novel efficient protocol for long-term AM preservation for future clinical applications.

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Microbial control through alternative therapies, such as the amniotic membrane (AM) and antimicrobial photodynamic therapy (aPDT), has been gaining prominence with the advancement of bacterial resistance to conventional treatments. This study aimed to evaluate the antimicrobial effect of AM isolated and associated with aPDT using the PHTALOX® as a photosensitizer (PS) against Staphylococcus aureus and Pseudomonas aeruginosa biofilms. The groups studied were: C+; L; AM; AM+L; AM+PHTX; and AM+aPDT. The irradiation parameters were 660 nm, 50 J.cm-2, and 30 mW.cm-2. Two independent microbiological experiments were carried out in triplicate, and the results were analyzed by CFU/mL counting and a metabolic activity test, both statistically analyzed (p < 0.05). The integrity of the AM was verified after the treatments by a scanning electron microscope (SEM). The groups AM, AM+PHTX, and, mainly, AM+aPDT showed a statistical difference when compared to C+ regarding the decrease in CFU/mL and metabolic activity. SEM analysis showed significant morphological alterations in the AM+PHTX and AM+aPDT groups. The treatments with AM isolated or associated with PHTALOX® were adequate. The association had potentiated the biofilm effect, and the morphological differences presented by AM after treatment did not hinder its antimicrobial effect, encouraging its use in biofilm formation locals.

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Resumen OBJETIVO: Determinar los factores asociados con una prueba de trabajo de parto después de una cesárea exitosa en mujeres sin antecedente de parto previo. MATERIALES Y MÉTODOS: Estudio observacional de casos y controles, longitudinal, retrospectivo y analítico efectuado en pacientes atendidas entre el 2017 y 2020 en el Hospital Ángeles Lomas, con embarazo único de más de 37 semanas, con una prueba de trabajo de parto, con una cesárea previa y sin parto previo. Se compararon las variables independientes entre el grupo que logró una prueba exitosa de trabajo de parto después de cesárea con las del grupo con prueba fallida. Para el análisis estadístico se utilizó el programa SPSS de IBM, versión 21. Todas las variables categóricas se expresan en frecuencias y porcentajes. RESULTADOS: Se incluyeron 135 pacientes con prueba de trabajo de parto después de cesárea de las que 65 (48.1%) tuvieron parto (prueba exitosa) y 70 (51.8%) cesárea (prueba fallida). Hubo una mayor proporción de trabajo de parto espontáneo en el grupo con prueba exitosa en comparación con el grupo con prueba fallida (66.2% en comparación con 37.1%). No hubo diferencias significativas en cuanto a la conducción del trabajo de parto, integridad de membranas amnióticas al ingreso, horas de trabajo de parto y peso al nacer. CONCLUSIONES: Un índice de masa corporal menor, un trabajo de parto espontáneo y una mayor dilatación al ingreso se asociaron, significativamente, con una prueba exitosa de trabajo de parto después de cesárea. La integridad de las membranas, la duración de la prueba y el peso al nacer no tuvieron diferencias significativas entre los grupos.

Abstract OBJECTIVE: To determine the factors associated with a trial of labor after a successful cesarean section in women with no history of previous delivery. MATERIALS AND METHODS: Observational case-control, longitudinal, retrospective, analytical, retrospective study performed in patient attended between 2017 and 2020 at Hospital Ángeles Lomas, with a singleton pregnancy of more than 37 weeks, with a trial of labor, with a previous cesarean section and no history of previous delivery. The independent variables were compared between the group that achieved a successful trial of labor after cesarean section with those of the group with failed trial. For statistical analysis, the IBM SPSS program, version 21, was used. All categorical variables are expressed in frequencies and percentages. RESULTS: We included 135 patients with trial of labor after cesarean section of whom 65 (48.1%) had labor (successful trial) and 70 (51.8%) had cesarean section (failed trial). There was a higher proportion of spontaneous labor in the successful trial group compared to the failed trial group (66.2% compared to 37.1%). There were no significant differences in labor conduction, amniotic membrane integrity on admission, hours of labor, and birth weight. CONCLUSIONS: Lower body mass index, spontaneous labor, and greater dilation on admission were significantly associated with a successful trial of labor after cesarean section. Membrane integrity, length of trial, and birth weight had no significant differences between groups.

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This study aimed to evaluate the use of equine amniotic membrane (EAM), frozen indirectly using liquid nitrogen and stored between -10° and -24°C, in the treatment of equine skin lesions. Six healthy female horses, aged 3-10 years, were included in this study. EAM was collected from previously evaluated healthy parturient mares. Wounds were surgically created at the distal ends of the forelimbs. One limb was chosen for treatment, and the contralateral limb was chosen as the control. Pain sensitivity, presence of granulation tissue, secretions, and bleeding after debridement during cleaning were evaluated. Microscopically, the following were evaluated: the integrity of the epithelium, the organization of the connective tissue, the presence of hemorrhage, fibroplasia, epithelial hyperplasia, hyperkeratosis, neovascularization, and the types of cells present. Assessments were performed on days 0, 3, 7, 14, 21, 28, and 63, and the time to complete the lesion closure. Treatment with EAM promoted faster recovery, greater neovascularization, better quality fibroplasia, and less sensitivity to pain than the control group. We concluded that the use of EAM was advantageous compared to the control group.

O objetivo deste estudo foi avaliar a utilização da membrana amniótica equina (MAE) congelada indiretamente por meio do nitrogênio líquido e conservada entre -10° e -24°C no tratamento de lesões cutâneas de equinos. Foram empregados seis equinos, fêmeas, hígidas, com idades de 3 a 10 anos. A MAE foi coletada de éguas parturientes hígidas, previamente avaliadas. As feridas foram produzidas cirurgicamente nas extremidades distais dos membros anteriores. Um dos membros foi escolhido como tratado, permanecendo o contralateral como controle. Foram avaliados a sensibilidade dolorosa; presença de tecido de granulação; secreções; e hemorragia após desbridamento durante a limpeza. Microscopicamente foram avaliados: a integridade do epitélio, a organização do tecido conjuntivo, a presença de hemorragia, fibroplasia, hiperplasia epitelial, hiperqueratose, neovascularização e os tipos celulares presentes. As avaliações foram realizadas nos dias 0, 3, 7, 14, 21, 28, e 63, e o tempo até o fechamento completo da lesão. O tratamento com MAE promoveu uma recuperação mais rápida que o grupo controle, maior neovascularização, melhor qualidade fibroplasia e menor sensibilidade à dor. Conclui-se que o emprego da MAE foi vantajoso em relação ao grupo controle.

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Therapies to deep burn injuries remain a global challenge. Human amniotic membrane (hAM) is a biomaterial that has been increasingly explored by the field of regenerative medicine. A decellularized hAM (DhAM) can be used as scaffold for mesenchymal stromal cells (MSCs) to grow without the loss of their stemness potential, allowing its application as cell therapy for wound healing. In this work, we associated DhAM with adipose-derived MSCs (DhAM + AD-MSCs), as a therapy strategy for second-degree burns in a preclinical model. Animals with induced second-degree burns were divided into four groups: control, which consists of a non-adherent gauze; a synthetic commercial dressing as the positive control (Control+); DhAM; and DhAM plus rat AD-MSCs (DhAM + AD-MSCs), followed by detailed and long term analysis (5 weeks). The macroscopical analysis showed the healing improvement in the wound area after the DhAM + AD-MSC treatment. Histological analysis also showed no alteration in the animal organs and a regular epithelial progression in comparison to the control. This observation was also confirmed by the analysis of suprabasal layers in the neoepidermis with CK10, showing a stratified and differentiated epithelium, when compared to Control and Control+. A strong CD73 (ecto-5'-nucleotidase) labeling was observed in the first 2 weeks postburn in dermis and epidermis. The expression in dermis was stronger in the second week in the middle of the wound, when comparing the Control+ with DhAM + AD-MSCs (p= 0.0238). In the epidermis the expression of CD73 was increased in all regions when compared to the control. This data suggests the involvement of this protein on wound healing. A low CD11b labeling was observed in DhAM + AD-MSCs treatment group mainly in the last treatment week, in comparison to Control and Control+ (p< 0.0001), which indicates a reduction in the inflammatory process. MSCs through CD73 can release high concentrations of adenosine, an immunosuppressive molecule, suggesting that this could be the mechanism by which the inflammation was better modulated in the DhAM + AD-MSCs group. The results obtained with this preclinical model confirm the effectiveness and safety of this low-cost and highly available dressing for future clinical application as a therapy for burn treatments.

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Human amniotic membrane mesenchymal stem cells (hAM-MSC) secrete a myriad of components with immunosuppressive activities. In the present research, we aimed to describe the effect of prostaglandin E2 (PGE2) secreted by hAM-MSCs on neutrophil extracellular trap (NET) release and to characterize the role of its receptors (EP2/EP4) in PAD-4 and NFκB activity in neutrophils. Human peripheral blood neutrophils were ionomycin-stimulated in the presence of hAM-MSC conditioned medium (CM) treated or not with the selective PGE2 inhibitor MF-63, PGE2, EP2/EP4 agonists, and the selective PAD-4 inhibitor GSK-484. NET release, PAD-4, and NFκB activation were analyzed. Ionomycin induced NET release, which was inhibited in the presence of hAM-MSC-CM, while CM from hAM-MSCs treated with MF-63 prevented NET release inhibition. PGE2 and EP2/EP4 agonists, and GSK-484 inhibited NET release. EP2/EP4 agonists and GSK-484 inhibited H3-citrullination but did not affect PAD-4 protein expression. Finally, PGE2 and EP2/EP4 agonists and GSK-484 increased NFκB phosphorylation. Taken together, these results suggest that hAM-MSC exert their immunomodulatory activities through PGE2, inhibiting NET release in a PAD-4-dependent pathway. This research proposes a new mechanism by which hAM-MSC exert their activities when modulating the innate immune response and inhibiting NET release.

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Tissue engineering is an interdisciplinary field that applies the principles of engineering and life sciences toward the development of biological substitutes that restore, maintain, or improve tissue function. The aims of this work were to compare chemically and physically processed human Amniotic Membranes (hAM) and analyze the cytocompatibility and proliferation rate (PR) of two primary human mesenchymal stromal cell lines, from different sources and donor conditions seeded over these scaffolds. The evaluated hAM processes were: cold shock to obtain a frozen amniotic membrane (FEAM) with remaining dead epithelial cells, denudation of hAM with trypsin for 20/10 min (DEAM20/10) or treatment with sodium dodecyl sulfate to decellularized hAM (DAM). All samples were sterilized with gamma radiation. The selection of the treated hAM to then generate composites was performed by scanning and transmission electron microscopy and characterization by X-ray diffraction, selecting DEAM10 and FEAM as scaffolds for cell seeding. Two sources of primary human stromal cells were used, both developed by our researchers, human Dental Pulp Stem Cells (hDPSC) from living donors and human Mesenchymal Stromal Cells (hMSC) from bone marrow isolated from brain dead donors. This last line of cells conveys a novel source of human cells that, to our knowledge, have not been tested as part of this type of construct. We developed four in vitro constructs without cytotoxicity signs and with different PR depending on the scaffolds and cells. hDPSC and hMSC grew over both FEAM and DEAM10, but DEAM10 allowed higher PR.

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A perfect graft for wound care must be readily available without affecting the immune response, covering and protecting the wound bed. Considering previous studies have already established the use of hyaluronic acid (HA) for the treatment of wounds but the data presented on the amniotic membrane (AM) and its promising effects on healing still requires further investigation, this study aimed to evaluate the effects of the application of a decellularized amniotic membrane solubilized with hyaluronic acid on the healing process of cutaneous wounds on the 7th and 14th day, to evaluate the evolution of the wound and the inflammatory phases in these two times. Cutaneous lesions were excised from the dorsal region and 96 Wistar rats were divided into four groups: I-Excisional wound (EW); II-EW + AM; III-EW + HA; IV-EW + AM + HA. The present study demonstrated that the proposed combined therapy favors the tissue repair process of the epithelial lesion. Results showed a reduction in pro-inflammatory cytokines, an increase in anti-inflammatory cytokines, an increase in TGF-ß, and attenuation of oxidative stress, reducing the acute inflammatory response and promoting the beginning of tissue repair. We concluded that the proposed therapies accelerated the inflammatory process with anticipation of the repair phase.

Assuntos

RESUMO

The amniotic membrane (AM) is the inner part of the placenta. It has been used therapeutically for the last century. The biological proprieties of AM include immunomodulatory, anti-scarring, anti-microbial, pro or anti-angiogenic (surface dependent), and tissue growth promotion. Because of these, AM is a functional tissue for the treatment of different pathologies. The AM is today part of the treatment for various conditions such as wounds, ulcers, burns, adhesions, and skin injury, among others, with surgical resolution. This review focuses on the current surgical areas, including gynecology, plastic surgery, gastrointestinal, traumatology, neurosurgery, and ophthalmology, among others, that use AM as a therapeutic option to increase the success rate of surgical procedures. Currently there are articles describing the mechanisms of action of AM, some therapeutic implications and the use in surgeries of specific surgical areas, this prevents knowing the therapeutic response of AM when used in surgeries of different organs or tissues. Therefore, we described the use of AM in various surgical specialties along with the mechanisms of action, helping to improve the understanding of the therapeutic targets and achieving an adequate perspective of the surgical utility of AM with a particular emphasis on regenerative medicine.