Stem cells (SC) and amniotic membrane (AM) are recognized for their beneficial impacts on the healing of cutaneous wounds. Thus, this study evaluated the capacity of tissue repair in a skin lesion rat model. Forty Wistar rats were randomized into four groups: group I – control, with full-thickness lesions on the back, without SC or AM; group II–injected SC; group III – covered by AM; group IV–injected SC and covered by AM. Lesion closure was assessed using contraction rate (Cr). Histochemical and immunohistochemical analyses were performed, and collagen, elastic fibers, fibroblast differentiation factor (TGF-β), collagen remodeling (MMP-8), and the number of myofibroblasts and blood vessels (α-SMA) were evaluated. On the 7^th postoperative day, Cr 1^st-7^th day levels were higher in groups III and IV. However, on the 28^th day, Cr 1^st-28^th day were higher in the control group. Picrosirius staining showed that type I collagen was predominant in all groups; however, the SC + AM group obtained a higher average when compared to the control group. Elastic fiber analysis showed a predominance in groups that received treatment. Groups II and IV showed the lowest expression levels of TGF-β and MMP-8, and α-SMA was significantly lower in group IV. The application of SC and AM accelerated the initial healing phase, probably owing to their anti-inflammatory effect that favored early formation of collagen and elastic fibers.

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-β 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-β. 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.

Several studies have focused on novel therapeutic strategies for extensive skin lesions aiming to improve healing quality and reduce treatment duration. In this context, the use of amniotic membrane (AM) and Wharton's jelly (WJ) emerges as promising alternatives. Full-thickness dorsal skin wounds were created in 21 Wistar rats, randomly divided into three groups: control (C), AM - covered by AM and WJ - covered by WJ. Wound contraction rate was measured weekly. On day 28, histochemical (Picrosirius red) and immunohistochemical analyses matrix metalloproteinase-9 (MMP-9), transforming growth factor beta (TGF-β), and alpha-smooth muscle actin (α-SMA) were performed. On day seven, wound contraction rate was higher in the AM group (38.8%), followed by the WJ (27.4%) and control (26.5%) with statistically significance. During the first 14 days, the AM group maintained the highest contraction rate, followed by the control and WJ groups. However, by day 21, wound contraction rates increased in the order of WJ to AM to control groups (85.6%, 87.0%, and 91.1%) with statistically significance. Type I collagen predominated across all groups, without statistically significant differences among them. TGF-β expression significantly increased from WJ to AM to control groups (19.75%, 26.00%, and 36.56%) with statistically significance. MMP-9 and α-SMA expressions decreased from control to WJ to AM groups, but no significant differences were observed. Both AM and WJ enhanced early wound contraction and may support skin repair by attenuating fibrotic signaling. These findings highlight the potential of AM and WJ as biomaterials for promoting tissue regeneration at epithelial barriers.

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.

The treatment of tracheal pathologies remains challenging.Nanotechnology allows adding substances to decellularized human amniotic membrane (DHAM), such as 15-Deoxy-∆12,14ProstaglandinJ2 nanoparticles (15D-PGJ2-NC).This study performed a tracheotomy in rabbits randomized into three groups.The tissue repair process was evaluated when treated with DHAM associated or not with 15D-PGJ2-NC.The average of the area in the control group was 54.76% smaller than DHAM group and 41.98% smaller than DHAM + 15D-PGJ2-NC group (p=0.004 for both).The DHAM + 15D-PGJ2-NC group had significantly more immature cartilage (p=0.015).DHAM impregnated with 15D-PGJ2-NC could provide support for the healing of the tracheal defect and may prevent reduction of its lumen.

Disorders of the Achilles tendon are common and have a major socio-economic impact. Current treatments (drugs, physiotherapy, and surgery) do not provide lasting relief, leading to chronicity and recurrence. In this context, experimental studies on regenerative therapies, such as stem cells, and natural and synthetic membranes, have shown promising results in the treatment of tendon lesions. Background/Objectives: The present study analyzes the response of tissue to a combination of bone marrow mononuclear cells (BMMCs) and human decellularized amniotic membrane (AM) for the treatment of Achilles tendon lesions in rats. Methods: Forty male Wistar rats were randomized into four treatment groups: SC (stem cells), AM (amniotic membrane), SC + AM (stem cells + amniotic membrane), and C (control). All underwent Achilles tendon sectioning and tenorrhaphy. In the AM and SC + AM groups, the amniotic membrane was sutured over the lesion after the tendon was sutured; in the SC and SC + AM groups, 2 mL of autologous blood from the iliac crest containing BMMCs was applied around the lesion. Animals in Group C received only 2 mL of 0.9% saline around the lesion. After four weeks, the animals were euthanized, and the tendons were sent for histological analysis (Picrosirius Red) and immunohistochemistry (IL-6, IL-4, and IL-13). Results: Analysis of type I and type III collagen fibers showed no differences between groups. However, the SC + AM group showed the highest expressions of IL-4 and IL-13. Conclusions: IL-4 and IL-13 are cytokines known to be associated with tissue repair and organization. This suggests that the therapy associated with SC and AM is potentially beneficial in the treatment of injured Achilles tendons. However, further studies are necessary to clarify the benefits of this treatment for the function and biomechanical properties of the tendon and prove whether this association could represent a combined Advanced Therapy Medicinal Product (cATMP). Such a product would contain SC and a biological membrane, providing a mechanical structure for the injured tendon and active biological cells. Another possible medical approach could be immunobiological drugs targeting IL-4 and IL-13.