Mechanical properties, vagina

Synthetic implants were used for repair of anterior compartment prolapses, which can be caused by direct trauma resulting in damaged pelvic structures. The mechanical properties of these implants may cause complications, namely erosion of the mesh through the vagina. In this study, we evaluated, by modeling, the behavior of implants, during Valsalva maneuver, used to replace damaged uterosacral ligaments (USLs), mimicking a sacrocolpopexy repair. For this purpose, two synthetic implants (A® , for prolapse repair and B® , for Hernia repair) were uniaxially tested, and the mechanical properties obtained were incorporated in the computational models of the implants...

Pelvic organ prolapse (POP) is a multifactorial connective tissue disorder caused by damage to the supportive structures of the pelvic floor, leading to the descent of pelvic organs in the vagina. In women with POP, fibroblast function is disturbed or altered, which causes impaired collagen metabolism that affects the mechanical properties of the tissue. Ideal surgical repair, either native tissue repair or POP surgery using an implant, aims to create a functional pelvic floor that is load-bearing, activating fibroblasts to regulate collagen metabolism without creating fibrotic tissue...

Pelvic organ prolapse is a worldwide health problem to elderly women. Understanding its pathogenesis and an ideal animal model are crucial to developing promising treatments. The present study aimed to investigate new clinical significance and detailed mechanism of pelvic organ prolapse by comparing the structural, functional and molecular dysfunctions of pelvic organ prolapse in patient and Loxl1 deficient mice. Our results showed that human vagina tissues from prolapsed site showed disarranged collagen and elastic fibers compared with the non-prolapse tissue...

The use of vaginal surgical mesh to treat pelvic organ prolapse (POP) has been associated with high rates of mesh-related complications. In the present study, we prepared new kinds of meshes based on bacterial cellulose (BC) and collagen-coated BC (BCCOL) using a laser cutting method and perforation technique. The mechanical properties of pre-implanted BC meshes, including breaking strength, suture strength and rigidity, were equal to or exceeded those of available clinically used polypropylene meshes. An in vitro cellular assay revealed that BCCOL meshes exhibited enhanced biocompatibility by increasing collagen secretion and cell adhesion...

When ejaculated sperm travels through the vagina to the uterus, mucus secreted by the cervical canal generally filters out sperm having low motility and poor morphology. To investigate this selection principle in vivo, we developed a microfluidic sperm-sorting chip with a viscous medium (polyvinylpyrrolidone: PVP) to imitate the biophysical environment mimic system of the human cervical canal. The material property of the PVP solution was tuned to the range of viscosities of cervical mucus using micro-viscometry...

The vagina is a viscoelastic fibromuscular organ that provides support to the pelvic organs. The viscoelastic properties of the vagina are understudied but may be critical for pelvic stability. Most studies evaluate vaginal viscoelasticity under a single uniaxial load; however, the vagina is subjected to dynamic multiaxial loading in the body. It is unknown how varied multiaxial loading conditions affect vaginal viscoelastic behavior and which microstructural processes dictate the viscoelastic response. Therefore, the objective was to develop methods using extension-inflation protocols to quantify vaginal viscoelastic creep under various circumferential and axial loads...

Transvaginal meshes repair for treating pelvic organ prolapse (POP) was halted by the U. S. Food and Drug Administration (FDA) because they can lead to severe complications. Therefore, investigations of new therapeutic strategies are urgently needed. Cell-based regenerative therapy holds great promise for the repair and restoration of damaged tissue. Here, we generated a bioengineered graft by seeding human umbilical cord mesenchymal stem cells (HUMSCs) on bioscaffolds to reconstruct the damaged vagina. In the in vitro study, HUMSCs proliferated well and the density was appropriate after 5 days of culture...

The ability of the vagina to contract gives rise to a set of active mechanical properties that contribute to the complex function of this organ in-vivo. Regional differences in the morphology of the vagina have been long recognized, but the large heterogeneous deformations that the vagina experiences during contractions have never been quantified. Furthermore, there is no consensus regarding differences in contractility along the two primary anatomical directions of the vagina: the longitudinal direction (LD) and the circumferential direction (CD)...

The uterosacral ligaments (USLs) are important anatomical structures that support the uterus and apical vagina within the pelvis. As these structures are over-stretched, become weak, and exhibit laxity, pelvic floor disorders such as pelvic organ prolapse occur. Although several surgical procedures to treat pelvic floor disorders are directed toward the USLs, there is still a lot that is unknown about their function. This manuscript presents a review of the current knowledge on the mechanical properties of the USLs...

Oviduct, uterus, and vagina are derived from Müllerian ducts. But only in the vagina, the epithelium differentiates into stratified layers. Organ-specific secreted factors derived from the stroma of a neonatal mouse induce epithelial differentiation in the female reproductive tracts. However, the effects of the components and mechanical property of extracellular matrix (ECM) on the regulation of gene expression in the mesenchymal cells of neonatal stroma and differentiation of epithelium in the female reproductive tracts have been overlooked...

Interest is growing in "smart" vaginal microbicides as a strategy to protect women from sexual transmission of human immunodeficiency virus (HIV). The concept is based on the development of products featuring low drug release in acidic media such as vaginal fluid but switch to a fast release profile when the medium becomes neutral or slightly alkaline. This mimics the surge in pH occurring in the vagina after sexual intercourse due to the seminal fluid. Semen is the main vehicle for HIV-1, and increasing antiretroviral drug levels in the vagina upon ejaculation may contribute to enhanced protection against viral sexual transmission...

Pelvic organ prolapse is a common condition that affects 1 in 4 women across all age groups. It is mainly caused by vaginal birth injury and can be exacerbated by obesity and increased age. Until recently, treatment strategies often used non-degradable synthetic meshes for reconstructive surgery. However, owing to their frequent, unacceptable rate of adverse events such as mesh erosion, transvaginal meshes have been banned in many countries. Recent reports have highlighted the urgent need for biocompatible design of meshes for a safe and effective treatment in the long term...

OBJECTIVE: Polycarbonate urethane (PCU) is a new biomaterial, and its mechanical properties can be tailored to match that of vaginal tissue. We aimed to determine whether vaginal host immune and extracellular matrix responses differ after PCU versus lightweight polypropylene (PP) mesh implantation. METHODS: Hysterectomy and ovariectomy were performed on 24 Sprague-Dawley rats. Animals were divided into 3 groups: (1) PCU vaginal mesh, (2) PP vaginal mesh, and (3) sham controls...

Dyspareunia, also known as vaginal hyperalgesia, is a prevalent and debilitating symptom of gynaecological disorders such as endometriosis and vulvodynia. Despite this, the sensory pathways transmitting nociceptive information from female reproductive organs remain poorly characterised. As such, the development of specific treatments for pain associated with dyspareunia is currently lacking. Here, we examined, for the first time, (1) the mechanosensory properties of pelvic afferent nerves innervating the mouse vagina; (2) the expression profile of voltage-gated sodium (NaV) channels within these afferents; and (3) how pharmacological modulation of these channels alters vaginal nociceptive signalling ex vivo, in vitro, and in vivo...

BACKGROUND: Lactobacillus spp. dominating the vaginal microbiota of healthy women contribute to the prevention of urogenital and sexually transmitted infections. Their protective role in the vagina can be mediated by Lactobacillus cells themselves, metabolites or bacterial components, able to interfere with pathogen adhesion and infectivity. Vulvovaginal candidiasis (VVC) is a common genital infection, caused by the overgrowth of opportunistic Candida spp. including C. albicans, C. glabrata, C...

The vagina is an important organ of the female reproductive system that has been largely understudied in the field of biomechanics. In recent years, some research has been conducted to evaluate the mechanical properties of the vagina, but much has focused on characterizing the passive mechanical properties. Because vaginal contractions play a central role in sexual function, childbirth, and development and treatment of pelvic floor disorders, the active mechanical properties of the vagina must be also quantified...

Pelvic organ prolapse is a condition characterized by displacement of the vagina from its normal anatomical position leading to symptoms such as incontinence, physical discomfort, and poor self-image. Conservative treatment has shown limited success and surgical procedures often lead to severe complications. To improve the current treatment methods for prolapse, the viscoelastic properties of vaginal tissue need to be characterized. We determined the biaxial stress-relaxation response of vaginal tissue isolated from healthy pubertal gilts...

The female reproductive organs, specifically the vagina and cervix, are composed of various cellular components and a unique extracellular matrix (ECM). Smooth muscle cells exhibit a contractile function within the vaginal and cervical walls. Depending on the biochemical environment and the mechanical distension of the organ walls, the smooth muscle cells alter the contractile conditions. The contribution of the smooth muscle cells under baseline physiological conditions is classified as a basal tone. More specifically, a basal tone is the baseline partial constriction of smooth muscle cells in the absence of hormonal and neural stimulation...

The cervix is essential to a healthy pregnancy as it must bear the increasing load caused by the growing fetus. Preterm birth is suspected to be caused by the premature softening and mechanical failure of the cervix. The objective of this paper is to measure the anisotropic mechanical properties of human cervical tissue using indentation and video extensometry. The human cervix is a layered structure, where its thick stromal core contains preferentially aligned collagen fibers embedded in a soft ground substance...

PURPOSE OF REVIEW: The vaginal milieu in women differs from that of other mammals, including non-human primates, in composition of secretions, the endogenous microbiota, and level of acidity. These changes apparently reflect evolutionary variations that maximized productive responses to a uniquely human vaginal environment. This review will highlight recent findings on properties of human vaginal epithelial cells that contribute to maintenance of a healthy vaginal environment. RECENT FINDINGS: Vaginal epithelial cells are responsive to the composition of the vaginal microbiome even in women who are in apparently good health and do not exhibit any adverse physical symptoms...