Implantable electrical stimulation device enhances pelvic floor tissue repair and reduces collagen over-degradation in rats with stress urinary incontinence

Stress urinary incontinence (SUI) significantly impacts the quality of life of many elderly women. However, current treatment options have limited efficacy. In our previous research, we demonstrated that a novel miniature, wireless implantable electrical stimulation device (NuStim) is capable of improving the leak point pressure in a rat model of postpartum SUI. However, the underlying mechanism remains unclear. Therefore, we investigated the effects of Nustim on histological and collagen changes in the pelvic floor tissue. Hematoxylin and eosin staining was used to observe tissue structure and cellular morphology, Masson's trichrome staining was applied to assess collagen fiber content, and electron microscopy was utilized to examine ultrastructural changes. Collagen content, matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) were measured using Western blot and enzyme-linked immunosorbent assay. Our findings revealed that after two weeks of Nustim treatment, the morphology of tissues, cells, and organelles improved, inflammatory responses were attenuated, and the levels of collagen content, MMPs, and TIMPs basically returned to normal. Nustim has a beneficial effect on alleviating the pathological changes and excessive collagen degradation, and may represent a promising therapeutic modality for SUI, with potential for clinical translation.