Bladder Reconstruction with Human Amniotic Membrane in a Xenograft Rat Model: A Preclinical Study

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.

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Amniotic membrane applied to burns healing: Pre-clinical study

Research Society and Development ◽

10.33448/rsd-v10i4.14286 ◽

2021 ◽

Vol 10 (4) ◽

pp. 38110414286

Author(s):

Fernanda Cláudia Miranda Amorim ◽

Emilia Ângela Loschiavo Arisawa ◽

Luciana Barros Sant’Anna ◽

Khetyma Moreira Fonseca ◽

Davidson Ribeiro Costa ◽

...

Keyword(s):

Amniotic Membrane ◽

Healing Process ◽

Inflammatory Cells ◽

Repair Process ◽

Treated Group ◽

Preclinical Study ◽

Control Group ◽

Human Amniotic Membrane ◽

Significance Level ◽

Kolmogorov Smirnov

This preclinical study aimed to evaluate the tissue repair process of burns treated with human amniotic membrane (hAM) patches in rats. Twenty-four rats were subjected to superficial burns of partial thickness, and randomly allocated into two groups: Control and Treated Group, subdivided into two experimental periods of 7th and 14th days. The lesions were evaluated by digitalized images (macroscopy) and by the analysis of histological sections stained in H&E to quantify the number of inflammatory cells and fibroblasts present in the different experimental times (histomorphometry). The histomorphometric analyses were performed blindly. Statistical analysis employed Kolmogorov-Smirnov and Mann Whitney tests, with 95% confidence interval at 5% significance level (p <0.05). Macroscopically, the lesions of Treated group presented a crust formation before Control Group, and there were no signs of infection in both groups. Microscopically, the qualitative analysis showed a faster evolution in the healing process of the Treated groups compared to the Control, with reduction of the inflammatory infiltrate, intense fibroblasts proliferation and better organization of the collagen fibers. The quantitative analysis showed statistically significant results regarding the reduction of inflammatory cells (p<0.0001) at 7th and 14 th day and increased proliferation of fibroblasts at 14th day (p<0.0001) in lesions treated with hAM compared to Control group. The results of this preclinical study demonstrated that the application of hAM patches reduces the inflammatory process and accelerates the onset of the proliferative phase in burn injuries.

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