Abstract:  Objective · To investigate the micro/ nano structure of human vaginal wall acellular matrix, and provide parameters for bionic vagina.  Methods · A total of 35 vaginal specimens were obtained from 35 postmenopausal patients who underwent cystocele repair and/or rectocele repair. Cells in specimens were entirely removed, and the extracellular matrix was maintained. Then the acellular matrix was observed by general observation, H-E staining, Masson staining, scanning electron microscope and Micro-CT. The external and internal structure properties were measured and analyzed.  Results · All cells in 35 vaginal specimens were totally removed. The vaginal wall acellular matrix was a double-layer fibrous reticular structure composed of interlaced collagen fibers, which were further arranged into bundles. Pores were distributed among fiber bundles. Epithelial side structure of vaginal wall acellular matrix was dense and subepithelial tissue was loose. There was no significant difference in fiber diameter [(82.4±9.3) nm vs (87.5±10.2) nm, P=0.432] and fiber bundle thickness [(67.6±9.3) μm vs (65.3±5.2) μm, P=0.634] between the dense and loose layers. Fiber bundle separation [(180.1±24.5) μm vs (118.2±23.0) μm, P=0.003] and total porosity [(77.1±4.2)% vs (66.6±2.8)%, P=0.002] were higher in loose layer. There was no significant difference in the micro/nano structure parameters of the acellular matrix between the anterior vaginal wall and the posterior vaginal wall.  Conclusion · There was no significant difference in the fiber diameter and the fiber bundle thickness between the dense layer and the loose layer of vaginal wall acellular matrix, but the porosity of the dense layer fiber bundle was smaller than that of the loose layer.

Key words: vaginal wall, acellular matrix, scanning electron microscope, Micro-CT, micro/nano structures