Elastic Silicone Research Articles

A three-dimensional strain measurement method in elastic transparent materials using tomographic particle image velocimetry.

BackgroundThe mechanical interaction between blood vessels and medical devices can induce strains in these vessels. Measuring and understanding these strains is necessary to identify the causes of vascular complications. This study develops a method to measure the three-dimensional (3D) distribution of strain using tomographic particle image velocimetry (Tomo-PIV) and compares the measurement accuracy with the gauge strain in tensile tests.Methods and findingsThe test system for measuring 3D strain distribution consists of two cameras, a laser, a universal testing machine, an acrylic chamber with a glycerol water solution for adjusting the refractive index with the silicone, and dumbbell-shaped specimens mixed with fluorescent tracer particles. 3D images of the particles were reconstructed from 2D images using a multiplicative algebraic reconstruction technique (MART) and motion tracking enhancement. Distributions of the 3D displacements were calculated using a digital volume correlation. To evaluate the accuracy of the measurement method in terms of particle density and interrogation voxel size, the gauge strain and one of the two cameras for Tomo-PIV were used as a video-extensometer in the tensile test. The results show that the optimal particle density and interrogation voxel size are 0.014 particles per pixel and 40 × 40 × 40 voxels with a 75% overlap. The maximum measurement error was maintained at less than 2.5% in the 4-mm-wide region of the specimen.ConclusionsWe successfully developed a method to experimentally measure 3D strain distribution in an elastic silicone material using Tomo-PIV and fluorescent particles. To the best of our knowledge, this is the first report that applies Tomo-PIV to investigate 3D strain measurements in elastic materials with large deformation and validates the measurement accuracy.

03.21: Structural glued connections with different metal substrates

ABSTRACTIntensive studies of polymer adhesives for structural applications have opened up new possibilities of glued usage connections in civil engineering, especially in façade applications. Facades have to fulfil not only architectural requirements but there are also construction and material technology requirements, as well as functionality. Façade cladding connections with other façade parts can be advantageously designed as glued joints. In dependence on particular application, adhesive bonding provides higher efficiency of workmanship in comparison with bolted connection and esthetical qualities, e.g. smooth, flat surface of façade cladding without visual interruption of bolts. Important benefit of glued connections in facades is elimination of local thermal bridge in comparison with bolted connections and possibility of stress peak reduction in dependence on adhesive and substrate stiffness and geometrical arrangement of the joint. Despite of wide usage of low strength and elastic silicone sealants for a long period of time in façades, there is a lack of information about semi‐flexible and semi‐rigid adhesives with higher strength and reasonable elongation at break. Building facade is a very specific type of usage for glued connections due to the requirements on durability, strict geometrical imperfections and joining of unconventional materials often used in the façade design. This paper reports on an experimental analysis focused on determining of the mechanical characteristics of two types of adhesive applied in double lap connection loaded by shear. The study comprises two basic substrate materials, aluminium and galvanised steel, with various surface treatments. Galvanized steel was used with clean, smooth surface and roughened surface; aluminium substrates were applied with clean smooth surface, roughened surface and with anodised covering to find out effect of roughening and anodization of aluminium on adhesion. Material and surface treatment has great influence not only on adhesion and thus strength of the joint, but also on failure mode, behaviour and safety of particular joint. Moreover, every necessary surface treatment creates higher labour intensity, higher time consumption and thus increased costs on building/facade construction.

High-Frequency Modeling and Signal Integrity Analysis of a Silicone Rubber Socket for High-Performance Package

As a demand for electrical systems with a wide data bandwidth has increased, high-performance packages ensuring high data rates, such as low power double data rate series, have become common. The need for high-performance test sockets has also emerged to test these packages. However, a conventional pogo pin socket has a limited test bandwidth due to the parasitic components arising from its spring. On the other hand, a silicone rubber socket satisfies the wide bandwidth requirement because it has low parasitic components due to high-density conductive metal powders in an elastic silicone rubber. In this paper, we propose an RLGC equivalent circuit model of a silicone rubber socket and first experimentally verify it. The proposed model is experimentally verified in the frequency domain by comparing the insertion loss obtained from the proposed model to the measurement up to 20 GHz. The proposed model is experimentally verified in the time domain by comparing the eye diagrams obtained from the proposed model to the measurement at a data rate of 12.5 Gb/s. Also, the insertion loss of the sockets with varied height, diameter, and pitch is analyzed using the proposed model. The proposed model provides physical insight of a silicone rubber socket, and it allows to determine whether a socket is reliable for testing high performance packages in a short time. It also gives us the idea how to design a high-performance test socket. Furthermore, we discuss the current capacity and life cycle of the silicone rubber socket in terms of signal integrity as well.

Aluminum nitride–filled elastic silicone rubber composites for drag reduction

This study presents aluminum nitride/silicone rubber composite as a drag reduction material, inspired by the boundary heating drag reduction mechanism of dolphin skin. Aluminum nitride was added as a thermal conductive filler at weight fractions of 16.67, 21.05, and 28.57 wt% to pristine silicone rubber. Tests of the thermal conductivity and tensile properties showed that the thermal conductivity of all three aluminum nitride/silicone rubber composites were increased 27.9%, 41.4%, and 43.7% than that of the pristine silicone rubber, and the elastic modulus of the composites was increased with the aluminum nitride content. Droplet velocity testing, which can reflect the drag reduction mechanism of the heating boundary controlled by the aluminum nitride/silicone rubber composites, was performed between all three aluminum nitride/silicone rubber composites and pristine silicone rubber. The results showed that the droplet velocity of all three aluminum nitride/silicone rubber composites were higher than pristine silicone rubber, implying that the composites had a drag-reducing function. In terms of the drag-reducing mechanism, the heat conductivity performance of the aluminum nitride/silicone rubber accelerates the heat transfer between the aluminum nitride/silicone rubber composite surface and droplet. The forces between the molecules and droplet dynamic viscosity are reduced, which result in drag reduction. The application of aluminum nitride/silicone rubber composite to control fluid medium will have important value for fluid machinery.

Bio-inspired Graphene-enhanced Thermally Conductive Elastic Silicone Rubber as Drag Reduction Material

This study presented a graphene platelet/silicone rubber (GPL/SR) composite as a drag reduction material, inspired by the boundary heating drag reduction mechanism of dolphin skin. Graphene was added as a thermally conductive filler at weight fractions of 0.17 wt%, 0.33 wt% and 0.67 wt% to pristine silicone rubber (PSR). Tests of the thermal conductivity and tensile properties showed that the thermal conductivity of all three GPL/SR materials of 0.17 wt%, 0.33 wt% and 0.67 wt% graphene were 20%, 40% and 50% higher than that of the PSR, respectively, and the elastic modulus of the 0.17 wt% GPL/SR materials was lowest. Droplet velocity testing, which can reflect the drag reduction mechanism of the heating boundary controlled by the GPL/SR composite, was performed between 0.33 wt% GPL/SR, which typically exhibits good mechanical properties and thermal conductivity performance, and the PSR. The results showed that on the 0.33 wt% GPL/SR, the droplet velocity was higher and the rolling angle was lower, implying that the GPL/SR composite had a drag-reducing function. In terms of the drag reduction mechanism, the heat conductivity performance of the GPL/SR accelerated the heat transfer between the GPL/SR composite surface and the droplet. The forces between the molecules decreased and the droplet dynamic viscosity was reduced. The drag of a sliding water droplet was proportional to the dynamic viscosity, which resulted in drag reduction. The application of GPL/SR material to the control fluid medium should have important value for fluid machinery.

A Highly Stretchable Fiber‐Based Triboelectric Nanogenerator for Self‐Powered Wearable Electronics

The development of flexible and stretchable electronics has attracted intensive attention for their promising applications in next‐generation wearable functional devices. However, these stretchable devices that are made in a conventional planar format have largely hindered their development, especially in highly stretchable conditions. Herein, a novel type of highly stretchable, fiber‐based triboelectric nanogenerator (fiber‐like TENG) for power generation is developed. Owing to the advanced structural designs, including the fiber‐convolving fiber and the stretchable electrodes on elastic silicone rubber fiber, the fiber‐like TENG can be operated at stretching mode with high strains up to 70% and is demonstrated for a broad range of applications such as powering a commercial capacitor, LCD screen, digital watch/calculator, and self‐powered acceleration sensor. This work verifies the promising potential of a novel fiber‐based structure for both power generation and self‐powered sensing.

Surface Chemistry: Superamphiphobic, Magnetic, and Elastic Silicone Sponges with Excellent Temperature Stability (Adv. Mater. Interfaces 23/2016)

Surface Chemistry: Superamphiphobic, Magnetic, and Elastic Silicone Sponges with Excellent Temperature Stability (Adv. Mater. Interfaces 23/2016)

Superamphiphobic, Magnetic, and Elastic Silicone Sponges with Excellent Temperature Stability

It is very challenging to create bioinspired superamphiphobic 3D porous materials that resist wetting of organic liquids with low surface tension. Here, preparation of superamphiphobic, magnetic, and elastic (SAME) silicone sponges is reported with excellent temperature stability. The SAME silicone sponges are prepared by hydrolytic condensation of methyltrimethoxysilane and dimethoxydimethylsilane in the presence of urea, n‐hexadecyltrimethyl ammonium bromide, and the Fe3O4@SiO2 nanoparticles, followed by surface modification with 1H,1H,2H,2H‐perfluorodecyltriethoxysilane (PFDTES) and tetraethoxysilane (TEOS). The SAME silicone sponges are characterized using a wide range of analytical techniques including scanning electron microscopy, X‐ray photoelectron spectroscopy, and thermal gravimetric analysis. It is found that the wettability of the SAME silicone sponges can be controllable simply by regulating their surface topography and surface chemical composition, in other words, the volume ratio of PFDTES and TEOS. The residual silanol groups on the pore surface of the silicone sponge act as the active sites for the hydrolytic condensation of PFDTES and TEOS. The SAME silicone sponges feature excellent superamphiphobicity for water and various organic liquids of low surface tension, fast magnetic responsiveness, high compressibility (90%), and stretchability (35%) as well as high stability in a wide range of temperature (−196–300 °C).

Stretchable Silver Nanowire Microelectrodes for Combined Mechanical and Electrical Stimulation of Cells.

The use of stretchable electrodes interfaced with the human body has enabled a new frontier in biomedical engineering, and the miniaturization of such electrodes can allow for a more precise spatial control to monitor or stimulate tissues. The understanding of the response of cells or tissues to combined electromechanical stimulation, as made possible by stretchable electrodes, is essential to improve medical devices and therapies. Cheap to produce and easy to use platforms for in vitro cell studies are thus urgently needed. This study reports the successful implementation of silver nanowires (AgNWs) into an integrated miniaturized electromechanical stimulator, which is compatible with cell culture. The innovative steps include a lithography-based lift-off method to micropattern AgNWs onto an elastic silicone membrane. These stretchable microelectrodes are then integrated into a microfluidic device for cell culture, which enables the synchronous electromechanical stimulation of cells. In a proof-of-concept study, it is furthermore shown that fibroblasts respond uniquely to mechanical stretching, electrical stimulation, and combined electromechanical stimulations in terms of cell alignment and morphology, as well as by producing the extracellular matrix protein collagen. This proof-of-concept study illustrates the functionality and usability of these stretchable AgNWs microelectrodes for either basic research or future biomedical applications.

Cellular Contractile Forces Measured a Multi-Well Silicone Device Reveal Physical Forces that Control Cell Migration in Physiology and Disease

Cell migration is a highly integrated process and basic to many biological functions ranging from development to immune response and wound healing, to metastasis in cancer. For cells to migrate, they must generate and transduce traction forces to their environment, however, no technology to date has provided a high throughput solution for measuring these traction forces. Here we present a new assay for measuring cellular contractile forces employing robust multiwall culture plates: Using a 96-well plate format, we fabricate soft (∼1-10 kPa) elastic silicone rubbers with embedded fiduciary particles; by measuring the cell-induced deformation of these particles we calculate the cellular traction stresses and work using Fourier transform cytometry. We utilize this system to quantify the traction mechanics underlying cellular migration in several diseased settings including cancer metastasis, induced epithelial to mesenchymal transition (EMT), and aging; in all instances, we find significant changes in the contractile stresses and work, suggesting that contractile force screening may become a valuable biophysical diagnostic addition. This 96-well format and the use of a non-degrading soft silicone rubber create a simple and stable assay, and we anticipate that this technology will be of broad utility in diverse quantitative biological and health sciences.

Hertzian load–displacement relation holds for spherical indentation on soft elastic solids undergoing large deformations

In this paper we investigate the validity of the Hertz theory at very large deformations by performing rigid spherical indentation on soft, linearly elastic silicone substrates using nanoindentation tests and finite element method. We show that the theory significantly underestimates and overestimates the contact radius and maximum contact pressure, respectively, as the ratio of indenter displacement δ to the indenter radius R exceeds 0.1. However, the loading load–displacement relation still holds (<3% discrepancy) for δ/R as large as 0.66 with a maximum principal strain of 46.6%. This agreement arises from a near cancellation of two non-Hertzian effects: the spherical (as opposed to paraboloidal) shape of the indenter, and the large deformation behavior of the linear elastic system. Our simulation results show that the Hertzian load–displacement relation does not hold for thin films where the ratio of thickness H to R is smaller than 20. We also consider rigid indentation on an elastic sphere with a radius of kR, and reveal that the elastic sphere is large enough to be treated as a half-space for k>10. Our results may provide practical guidelines to proper sample preparation and better interpretation of indentation data of elastic soft elastomers and gels.

Growth on elastic silicone substrate elicits a partial myogenic response in periodontal ligament derived stem cells

The processes of cellular differentiation and phenotypic maintenance can be influenced by stimuli from a variety of different factors. One commonly overlooked factor is the mechanical properties of the growth substrate in which stem cells are maintained or differentiated down various lineages. Here we explored the effect that growth on an elastic silicone substrate had on the myogenic expression and cytoskeletal morphology of periodontal ligament derived stem cells. Cells were grown on either collagen I coated tissue culture polystyrene plates or collagen I coated elastic silicone membranes for a period of 4 days without further induction from soluble factors in the culture media. Following the 4-day growth, gene expression and immunohistochemical analysis for key cardiomyogenic markers was performed along with a morphological assessment of cytoskeletal organization. Results show that cells grown on the elastic substrate significantly upregulate key markers associated with contractile activity in muscle tissues. Namely, the myosin light chain polypeptides 2 and 7, as well as the myosin heavy chain polypeptide 7 genes underwent a statistically significant upregulation in the cells grown on elastic silicone membranes. Similarly, the cells on the softer elastic substrate stained positive for both sarcomeric actin and cardiac troponin t proteins following just 4 days of growth on the softer material. Cytoskeletal analysis showed that substrate stiffness had a marked effect on the organization and distribution of filamentous actin fibers within the cell body. Growth on silicone membranes produced flatter and shorter cellular morphologies with filamentous actin fibers projecting anisotropically throughout the cell body. These results demonstrate how crucial the mechanical properties of the growth substrate of cells can be on the ultimate cellular phenotype. These observations highlight the need to further optimize differentiation protocols to enhance the application of cellular products in the fields of regenerative medicine and stem cell therapies.

A Twisted Bundled Tube Locomotive Device Proposed for In-Pipe Mobile Robot

This paper presents a novel device that propagates through small pipes, named the twisted bundled tube locomotive device. The device consists of three elastic silicone rubber tubes that are twisted and bonded. When any tube is pressurized, it inflates, and the device deforms into a helix. If these tubes are sequentially pressurized, the device exhibits helical rotation, that is, it rotates about its body axis while retaining its helical shape. Thus, the device moves along the pipe axis. Since helical rotation is generated by bending motion alone, the device is highly airtight, and thus strongly resistant to the environment. Helical rotating motion does not scratch the inner wall of the pipe or block the flow in the pipe. The device can be made sufficiently small to travel through thin pipes, because of its simple structure. The device is very flexible and can pass through an elbow-pipe without requiring complicated control. Therefore, the device could be adopted in endoscopes used for pipe inspection. The propulsion principle and the theoretical velocity of the device are discussed and confirmed in prototypes. The manufacturing method for the prototype is also presented. The small prototype (approximate diameter 6 mm) travels at 45 mm/s in a 20-mm diameter pipe, and it passes through the elbow. Moreover, a prototype equipped with a camera can send images of the camera view as it moves the pipe.

Fuzzy logic modelling of a transparent and elastic silicone pad for a new and novel optic based tactile sensor

Tactile sensing usually refers to a transducer that is sensitive to touch, force or pressure like human skin. A tactile-sensing array can be considered as a coordinated group of touch sensors. Recently, there has been an increased interest in tactile sensors, yet, the desired level, compared to the human’s sensing ability still could not be reached for parameters such as the number of receptors at a certain area. A new, novel and also patented design proposes using change in density of light due to the deformation on contact surface. In this design, an elastic silicone pad that mimics the tissue under the skin of human beings is used. An external stimulus excites on this pad; therefore, a relative deformation occurs. This deformation (displacement) is measured optically by this new sensor. In order to quantify the force map on the contact/measurement surface, a mathematical model is needed in which the input is the displacement and the output is the force. In this paper, both an analytical model and a fuzzy logic model are introduced and compared in order to satisfy this mandatory mathematical model of the silicone pad.

Vaginal Rejuvenation with Gore-Mycromesh.

Recently, we introduced functional vaginal rejuvenation with elastic silicone threads. However, some patients with specific indications need other biocompatible materials for rejuvenation of the vagina. Gore-Mycromesh is one of the most commonly used materials in plastic and reconstructive surgical fields and it is composed of expanded poly-tetrafluroethylene. In this study, we introduced our clinical experience with static vaginal rejuvenation using Gore-Mycromesh to specifically assess the overall patient satisfaction (Female Sexual Function Index, FSFI). This study included 50 patients who underwent vaginal rejuvenation with a Gore-Mycromesh between 2010 and 2012. After marking two incisions at the inner side of the vaginal inlet and posterior wall, respectively, we performed submucosal dissection at the posterior vaginal wall and then grafted and secured a Gore-Mycromesh to the dissected area (muscle/fascia). Overall the FSFI improved as time progressed up to a year postoperatively. This is especially prominent in the FSFI satisfaction subscore. All but eight patients (42/50, 84 %) were "very satisfied (5)" or "satisfied (4)" with the outcomes after the vaginal rejuvenation. The overall complication rate was 8 %. Based on our clinical experience with the 50 cases, we think that vaginal rejuvenation with Gore-Mycromesh significantly improved postoperative outcomes, resulting in improved sexual function with a focus on improving the FSFI satisfaction subscore in mid-term follow-up. Elderly patients experience better outcomes using gore mycromesh rather than silicone thread because we can plicate the vaginal posterior wall with senile changes simultaneously using an open technique. However, further studies would be warranted for better positioning and adherence of grafted implants to surrounding tissue and for increasing the tightening effect of the implant and its sufficient longevity.

Tissue Engineering for Intervertebral Disc Repair and Regeneration

Introduction Tissue engineering aims to combine isolated cells, engineered materials and small molecule biochemical factors to generate neotissues with specific form and function to replace or repair damaged or degenerate native tissue. Intervertebral disc (IVD) degeneration directly causes back pain, and understanding how to regenerate this tissue may help alleviate this costly global problem. Several studies have combined isolated nucleus pulposus (NP) disc cells with novel scaffold materials to produce promising therapeutics toward IVD repair. We have taken three avenues toward IVD tissue engineering: culturing isolated IVD cells on continuous expansion surfaces to enhance cell phenotypes, utilizing novel injectable hydrogels for cell delivery to intact discs, and production of 3D printed scaffold geometries enhancing disc matrix production by seeded NP cells. Material and Methods Bovine NP cells were isolated from caudal discs of freshly slaughtered steer (∼ 24 months) obtained from a local slaughterhouse. Bovine NP cells are expanded on either tissue culture plastic with two passages, or on highly elastic silicone rubber dishes which slowly expands the surface from 12 to 78 cm2 and marker gene expression is compared. Isolated cells are labeled with fluorescent membrane binding dye, and cells are mixed with an injectable, chitosan/hyaluronic acid hydrogel. Approximately 100 µL of cell/gel (106 cells/µL of gel) mixtures is injected into isolated whole bovine discs (obtained as described earlier, with vertebral bone drilled down to the cartilage end plate). Discs are then placed into a custom bioreactor, and dynamic diurnal loading is applied to the injected discs. After 14 days, localization and viability of injected cells is assessed by confocal microscopy. For 3D printed constructs, 10 × 10 × 0.3 mm plastic scaffolds were printed using a desktop 3D printer, with pore size of approximately 700 µm. Overall, 5 × 105 bovine NP cells were seeded on scaffolds, and cell viability, DNA content, proteoglycan content, and collagen type II content was assessed after 21 days in culture. Results When cultured on elastic silicone dishes, continuous expansion of bovine NP cells preserve cell phenotype and promotes higher aggrecan and collagen type II expression compared with tissue culture plastic controls. NP cells embedded in a hydrogel and injected into whole discs were localized throughout the discs. Cells also showed high viability after 14 days in culture. Bovine NP cells seeded on 3D printed orthogonal plastic scaffolds grow extremely well and fill in the large 700 µm pores over 21 days culture. The cultured constructs have high viability and produce ample aggrecan and collagen type II protein. Conclusion By combining three different approaches we show the following: (1) individual NP cells can be engineered to maintain superior phenotypic qualities compared with standard culture procedures, (2) combination of expanded cells with injectable hydrogels can be delivered to intact discs for potential repair, and (3) simple 3D printed scaffolds can promote NP matrix production by seeded cells. Combination of these avenues may further enhance IVD regenerative capacities.

Viscoelastic modelling and experimental results of a dielectric electro‐active polymer diaphragm actuator

AbstractCommon actuating principles e.g. solenoids or piezo‐elements have mostly exploited their potential as electromechanical transducers. A new technology based on Dielectric Electro‐active Polymers (DEAPs) enables major progress in efficiency and functionality for actuators. In order to use the advantages of this new technology in a feasible application, a silicone based DEAP diaphragm actuator was tested experimentally. Here, the mechanical properties of the fundamental parts of the DEAP diaphragm actuator, namely the stressstrain behaviour of an equibiaxially pre‐stretched hyperelastic polymer and the mechanical response of a DEAP diaphragm actuator, were determined by appropriate test benches.The investigated DEAP diaphragm actuator consists of a dielectric, which corresponds to a thin elastic silicone film sandwiched between two compliant electrodes. Furthermore, DEAPs are pre‐stretched, actually up to five times their in‐plane dimensions, in order to improve their performance. In that context, the influence of the pre‐stretched state on the actuator performance was investigated. In addition, a viscoelastic finite‐element model of the electromechanical system has been developed and validated with the experimental results. The mechanical part of the DEAP diaphragm actuator was realized with an incompressible isotropic elastic model, whereas the electrical part was approximated with a circular parallel‐plate capacitor. (© 2014 Wiley‐VCH Verlag GmbH &amp; Co. KGaA, Weinheim)

Prototype emitter for use in subsurface drip irrigation: Manufacturing, hydraulic evaluation and experimental analyses

The current research aims to analyse theoretically and evaluate a self-manufactured simple design for subsurface drip irrigation (SDI) emitter to avoid root and soil intrusion. It was composed of three concentric cylindrical elements: an elastic silicone membrane; a polyethylene tube with two holes drilled on its wall for water discharge; and a vinyl polychloride protector system to wrap the other elements. The discharge of the emitter depends on the change in the membrane diameter when it is deformed by the water pressure. The study of the operation of this emitter is a new approach that considers mechanical and hydraulic principles. Thus, the estimation on the membrane deformation was based on classical mechanical stress theories in composite cylinders. The hydraulic principles considered the solid deformation due to force based on water pressure and the general Darcy–Weisbach head-loss equation. Twenty emitter units, with the selected design, were handcrafted in a lathe and were used in this study. The measured pressure/discharge relationship for the emitters showed good agreement with that calculated by the theoretical approach. The variation coefficient of the handcrafted emitters was high compared to commercial emitters. Results from field evaluations showed variable values for the relative flow variation, water emission uniformity and relative flow rate coefficients, but no emitter was obstructed. Therefore, the current emitter design could be suitable for SDI following further studies to develop a final prototype.

Functional vaginal rejuvenation with elastic silicone threads: A 4-year experience with 180 patients

Recently, there has been growing interest in female genital plastic surgery. To the authors’ knowledge, no studies have adopted elastic silicone thread for vaginal rejuvenation. This study introduces clinical experience over 4 years with vaginal rejuvenation using elastic silicone thread to specifically assess the overall patient satisfaction (sexual function and correction of the vaginal width). It is hypothesised that this novel surgical method can improve sexual function. Between 2007–2011, 180 patients underwent vaginal rejuvenation using elastic silicone thread performed by the authors at a single institution. Patients with persistent feeling of a wide vagina and/or a decreased ability to reach orgasm were included. Patients were excluded from the study if they were unavailable for follow-up, or if they had been diagnosed with any gynecologic diseases. To measure the 15 degree of improvement with regard to sexual function, this study adopted the validated system; Female Sexual Function Index (FSFI). 92.8% (167/180) of the patients were satisfied with outcome with regard to feelings of correction of vaginal width. Vaginal rejuvenation using elastic silicone thread significantly improved postoperative outcomes, resulting in improved sexual function, with a focus on improving the FSFI score. This is especially prominent in FSFI orgasm subscore. However, a prospective multicentre study would be beneficial to provide patients with the best possible management.

Mechanical stretch upregulates proteins involved in Ca2+ sensitization in urinary bladder smooth muscle hypertrophy.

Partial bladder outlet obstruction (pBOO)-induced remodeling of bladder detrusor smooth muscle (DSM) is associated with the modulation of cell signals regulating contraction. We analyzed the DSM from obstructed murine urinary bladders for the temporal regulation of RhoA GTPase and Rho-activated kinase (ROCK), which are linked to Ca(2+) sensitization. In addition, the effects of equibiaxial cell stretch, a condition thought to be associated with pBOO-induced bladder wall smooth muscle hypertrophy and voiding frequency, on the expression of RhoA, ROCK, and C-kinase-activated protein phosphatase I inhibitor (CPI-17) were investigated. DSM from 1-, 3-, 7-, and 14-day obstructed male mice bladders and benign prostatic hyperplasia (BPH)-induced obstructed human bladders revealed overexpression of RhoA and ROCK-β at the mRNA and protein levels compared with control. Primary human bladder myocytes seeded onto type I collagen-coated elastic silicone membranes were subjected to cyclic equibiaxial stretch, mimicking the cellular mechanical stretch in the bladder in vivo, and analyzed for the expression of RhoA, ROCK-β, and CPI-17. Stretch caused a significant increase of RhoA, ROCKβ, and CPI-17 expression. The stretch-induced increase in CPI-17 expression occurs at the transcriptional level and is associated with CPI-17 promoter binding by GATA-6 and NF-κB, the transcription factors responsible for CPI-17 gene transcription. Cell stretch caused by bladder overdistension in pBOO is the likely mechanism for initiating overexpression of the signaling proteins regulating DSM tone.