Bone-marrow mononuclear cells and acellular human amniotic membrane improve global cardiac function without inhibition of the NLRP3 Inflammasome in a rat model of heart failure.

Recent studies have suggested that therapies with stem cells and amniotic membrane can modulate the inflammation following an ischemic injury in the heart. This study evaluated the effects of bone-marrow mononuclear cells (BMMC) and acellular human amniotic membrane (AHAM) on cardiac function and NLRP3 complex in a rat model of heart failure.On the 30th day,the echocardiographic showed improvements on ejection fraction and decreased pathological ventricular remodeling on BMMC and AHAM groups.Oxidative stress analysis was similar between the three groups,and the NLRP3 inflammasome activity were not decreased with the therapeutic use of both BMMC and AHAM,in comparison to the control group.

Acellular Biomaterials Associated with Autologous Bone Marrow-Derived Mononuclear Stem Cells Improve Wound Healing through Paracrine Effects.

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.

Decellularized Wharton Jelly Implants Do Not Trigger Collagen and Cartilaginous Tissue Production in Tracheal Injury in Rabbits.

BACKGROUND: Tracheal lesions are pathologies derived from the most diverse insults that can result in a fatal outcome. Despite the number of techniques designed for the treatment, a limiting factor is the extent of the extraction. Therefore, strategies with biomaterials can restructure tissues and maintain the organ's functionality, like decellularized Wharton's jelly (WJ) as a scaffold. The aim is to analyze the capacity of tracheal tissue regeneration after the implantation of decellularized WJ in rabbits submitted to a tracheal defect. METHODS: An in vivo experimental study was undertaken using twenty rabbits separated into two groups (n = 10). Group 1 submitted to a tracheal defect, group 2 tracheal defect, and implantation of decellularized WJ. The analyses were performed 30 days after surgery through immunohistochemistry. RESULTS: Inner tracheal area diameter (p = 0.643) didn't show significance. Collagen type I, III, and Aggrecan highlighted no significant difference between the groups (both collagens with p = 0.445 and the Aggrecan p = 0.4). CONCLUSION: The scaffold appears to fit as a heterologous implant and did not trigger reactions such as rejection or extrusion of the material into the recipient. However, these results suggested that although the WJ matrix presents several characteristics as a biomaterial for tissue regeneration, it did not display histopathological benefits in trachea tissue regeneration.

Tracheal Repair with Human Umbilical Cord Mesenchymal Stem Cells Differentiated in Chondrocytes Grown on an Acellular Amniotic Membrane: A Pre-Clinical Approach.

Acellular amniotic membrane (AM) has been studied, with promising results on the reconstruction of lesioned tissues, and has become an attractive approach for tracheal repair. This study aimed to evaluate the repair of the trachea with human umbilical cord mesenchymal stem cells (hucMSCs) differentiated in chondrocytes, grown on an experimental model. Tracheal defects were induced by surgical tracheostomy in 30 New Zealand rabbits, and the acellular amniotic membrane, with or without cells, was covering the defect. The hucMSCs were isolated and cultivated with chondrogenic differentiation over the culture of 14 days, and then grown on the AM. In this study, the AM was biocompatible and hucMSCs differentiated into chondrocytes. Our results demonstrated an important role for AM with cultured cells in the promotion of immature collagen, known to produce tissue regeneration. In addition, cartilaginous tissue was found at the tracheal defects, demonstrated by immunohistology results. This study suggests that this biomaterial implantation can be an effective future therapeutic alternative for patients with tracheal injury.

Bone-Marrow Stem Cells and Acellular Human Amniotic Membrane in a Rat Model of Heart Failure.

Myocardial infarction (MI) remains the leading cause of cardiovascular death worldwide and a major cause of heart failure. Recent studies have suggested that cell-based therapies with bone marrow stem cells (BMSC) and human amniotic membrane (hAM) would recover the ventricular function after MI; however, the mechanisms underlying these effects are still controversial. Herein, we aimed to compare the effects of BMSC and hAM in a rat model of heart failure. MI was induced through coronary occlusion, and animals with an ejection fraction (EF) < 50% were included and randomized into three groups: control, BMSC, and hAM. The BMSC and hAM groups were implanted on the anterior ventricular wall seven days after MI, and a new echocardiographic analysis was performed on the 30th day, followed by euthanasia. The echocardiographic results after 30 days showed significant improvements on EF and left-ventricular end-sistolic and end-diastolic volumes in both BMSC and hAM groups, without significant benefits in the control group. New blood vessels, desmine-positive cells and connexin-43 expression were also elevated in both BMSC and hAM groups. These results suggest a recovery of global cardiac function with the therapeutic use of both BMSC and hAM, associated with angiogenesis and cardiomyocyte regeneration after 30 days.

Tissue-engineered amniotic membrane in the treatment of myocardial infarction: a systematic review of experimental studies.

OBJECTIVE: myocardial infarction (MI) remains the leading cause of death worldwide. Cell-based therapies have become potential therapeutic approaches, attempting to recover the contractility of necrotic cardiomyocytes. In the present study, we aimed to systematically evaluate experimental studies on the use of tissue-engineered amniotic membrane (hAMC) in MI treatment. METHODS: a systematic review of literature published in PubMed, Embase and CENTRAL databases was conducted, until March 31, 2020, for experimental studies reporting on hAMC cell-therapy performed on LV function, MI size, paracrine effects, angiogenesis, and cell differentiation. Two reviewers selected the articles that met the inclusion criteria and disagreements were solved through a consensus. RESULTS: a total of 11 studies were included for data extraction. For the acute scenario, therapeutic use of hAMC after MI was capable of improving LV function in rats, mainly due to its paracrine effects (anti-apoptotic and anti-inflammatory) and associated with cardiomyocyte differentiation, MI size reduction and neo-angiogenesis. CONCLUSION: tissue engineered hAMC following MI provided clinically relevant benefits on cardiac function and ventricular remodeling.

Acellular Human Amniotic Membrane Scaffold with 15d-PGJ2 Nanoparticles in Postinfarct Rat Model.

The difficulty in the regeneration of cardiomyocytes after myocardial infarction is a major cause of heart failure. Together, the amniotic membrane and 15-deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) can help in the recovery of cardiomyocyte, as they present many growth factors and anti-inflammatory effect, respectively. The objective of this study is to compare the efficacy of Human Decellularized Amniotic Membrane Scaffold (AHAS) loaded with 15d-PGJ2 in improving ventricular function in a rat model of postinfarct ventricular dysfunction. Myocardial infarction was induced in 24 rats by left coronary occlusion. After a week, the animals were subjected to echocardiography for evaluation of left ventricle ejection fraction (LVEF), left ventricle end diastolic volume (LVEDV), and left ventricle end systolic volume (LVESV). Animals with ejection fraction <40% were included in the study and were randomized into three groups: control (n = 8), AHAS (n = 8) and AHAS +15d-PGJ2 (n = 8). In the AHAS group only the membrane was implanted, whereas in the AHAS +15d-PGJ2 the membrane +15d-PGJ2 was implanted on myocardial infarction. Echocardiographic evaluation was performed after 1 month. For histological analysis, heart tissue was stained with Gomori trichome, Sirius Red, the antibody against CD31 and connexin 43 (Cx43). There were no significant differences in the baseline LVEF, LVEDV, and LVESV in all groups. After 1 month, ejection fraction decreased in the control group but increased in the AHAS group and in the AHAS +15d-PGJ2 group in comparison with the control group. The LVEDV and LVESV in the AHAS and AHAS +15d-PGJ2 groups decreased compared with the control group, featuring a ventricular antiremodeling effect. Histopathology of the infarcted area identified the reduction of infarct size and collagen type 1 in the AHAS and AHAS +15d-PGJ2 groups. New blood vessels and cardiomyocytes have been identified in an infarcted area by CD31 and Cx43. AHAS +15d-PGJ2 provided an increase in the ejection fraction and prevented ventricular dilation in this postinfarction ventricular dysfunction model. Impact Statement Our study demonstrated reduction of myocardial fibrosis, proliferation of cardiomyocytes and increase in ejection fraction in rats after experimental acellular amniotic membrane scaffold (AHAS) carrying nanoparticles of 15d-PGJ2 scaffold engraftment in infarcted myocardium. AHAS grafts facilitated colonization of fibrotic myocardium regions with new contractile cells, in addition to preventing reduction of left ventricle wall thickness. This contribution is theoretically and practically relevant as current literature describes experimental studies performed on cardiac ischemic models which present conflicting results concerning cell types used in a research model.

Stem Cells and Platelet-Rich Plasma Enhance the Healing Process of Tendinitis in Mice.

OBJECTIVE: Achilles tendon pathologies occur frequently and have a significant socioeconomic impact. Currently, there is no evidence on the best treatment for these pathologies. Cell therapy has been studied in several animal models, and encouraging results have been observed with respect to tissue regeneration. This study is aimed at evaluating the functional and histological effects of bone marrow stem cell or platelet-rich plasma implantation compared to eccentric training in the treatment of Achilles tendinopathy in rats. METHODS: Fourty-one male Wistar rats received collagenase injections into their bilateral Achilles tendons (collagenase-induced tendinopathy model). The rats were randomly divided into four groups: stem cells (SC), platelet-rich plasma (PRP), stem cells+platelet-rich plasma (SC+PRP), and control (eccentric training (ET)). After 4 weeks, the Achilles tendons were excised and subjected to biomechanical and histological analyses (Sirius red and hematoxylin-eosin staining). RESULTS: Biomechanical assessments revealed no differences among the groups in ultimate tensile strength or yield strength of the tendons (p = 0.157), but there were significant differences in the elastic modulus (MPa; p = 0.044) and maximum tensile deformation (p = 0.005). The PRP group showed the greatest maximum deformation, and the SC group showed the highest Young's modulus (elasticity) measurement. In histological analysis (hematoxylin-eosin and Sirius red staining), there were no differences among the groups. CONCLUSION: PRP and SC+PRP yielded better biomechanical results than eccentric training, showing that these treatments offer better tend function outcomes. This theoretical rationale for the belief that cell therapies can serve as viable alternatives to current treatments chronic fibrotic opens the door for opportunities to continue this research.

Effect of the bone marrow derived-mononuclear stem cells transplantation in the growth, VEGF-R and TNF-alpha expression of endometrial implants in Wistar rats.

OBJECTIVE: To study the effect of bone marrow derived-mononuclear stem cells transplantation in the growth, VEGF-R and TNF-alpha expression of surgically induced endometriosis in an experimental model. STUDY DESIGN: This is an experimental study conducted in the Center for Health and Biological Sciences at the Pontifical Catholic University of Parana, Brazil. Endometriotic implants were surgically induced in 120 female Wistar rats. The animals with viable endometrial implant (larger than 25 mm(2)) were randomically divided into 3 groups to receive an intraperitoneal injection of 0.2 cc of saline solution (C group; n=30), a subcutaneous injection of 1mg/kg of leuprolide (L group; n=34), or an intraperitoneal injection of 5×10(6) bone marrow derived-mononuclear stem cells (SC group; n=36). They were sacrificed after 21 days to assess the implants' size and the tissue expression of vascular endothelial growth factor receptor (VEGF-R) and tumor necrosis factor-alpha (TNF-alpha). RESULTS: Treatment with leuprolide decreased the surface area of the endometriotic implant compared to the SC group and the C group. The absolute reduction in the surface area of the implant was 16.5mm, 0mm, and 0mm (p=0.007), respectively, and the percent reduction was 40.2%, 0%, and 0% (p=0.001). VEGF-R expression in the endometriotic implant decreased after treatment in the L and SC groups compared to the C group (409.6 µm(2) vs. 465 µm(2) vs. 920.9 µm(2), respectively; p=0.021). TNF-alpha expression also reduced in the L and SC groups compared to the C group (585.7 µm(2) vs. 549.3 µm(2) vs. 2402.1 µm(2), respectively; p<0.001). CONCLUSION: Bone marrow derived-mononuclear stem cells transplantation decreased the expression of VEGF-R and TNF-alpha in the endometriotic implant but did not reduce the surface area of the lesion.