MP08-20 DESIGN AND PROTOTYPING OF A DYNAMIC SLING FOR THE TREATMENT OF STRESS URINARY INCONTINENCE (2021)

You have accessJournal of UrologyBladder & Urethra: Anatomy, Physiology & Pharmacology (MP08)1 Sep 2021MP08-20 DESIGN AND PROTOTYPING OF A DYNAMIC SLING FOR THE TREATMENT OF STRESS URINARY INCONTINENCE Seelay Tasmim, Philippe Zimmern, and Taylor Ware Seelay TasmimSeelay Tasmim More articles by this author , Philippe ZimmernPhilippe Zimmern More articles by this author , and Taylor WareTaylor Ware More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000001981.20AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Synthetic and autologous sling placement is a common method of treatment for stress urinary incontinence (SUI). These slings, however, are static and lack the ability to change once implanted. An overtightened sling can cause urine retention and a loose sling can lead to residual SUI. Here, we focus on designing a dynamic sling made of a class of novel material, Liquid Crystal Elastomers (LCEs), capable of reversible shape changes around the urethra and with activation parameters relevant to in vivo conditions METHODS: LCEs are a class of rubbery materials that can be 3D printed and have the ability to undergo controlled and reversible shape change in response to temperature changes in the range of 37°C to 45°C, which is considered physiologically safe. Incorporation of Infrared (IR)-absorbing carbon black (CB) particles allows this shape change to be triggered with IR light delivered transcutaneously. LCE-CB slings were embedded in agar gels with varying stiffnesses to simulate scar-tissue-like environment. We studied the shape change of LCE-CB slings with varying CB concentration (0 – 0.4 wt%) and IR light intensities (200 – 800 mW/cm2). To evaluate the rise in temperature, LCE-CB slings were illuminated with varying IR light intensities for variable periods of time, and temperature at the sling surface and surrounding agar was evaluated. RESULTS: LCE-CB slings with 0.4 wt% CB embedded in 1% agar gel (100kPa modulus) undergo up to 5% actuation strain in response to 500 mW/cm2 IR light within 90 s. The devices return to the original shape within 60 s, where the majority of this actuation occurs within the first 15 seconds, figure 1A. An LCE CB sling, that is normally supporting the urethra, will reduce urethral support after actuation and allow for voiding, figure 1B. The temperature of agar surrounding the sling after 2 mins of continuous illumination of 500 mW/cm2 IR light reached a maximum of 44°C, which is below the threshold for thermal damage. Actuation of the sling was repeatable over 100 cycles. CONCLUSIONS: LCE-CB material could be used to 3D print patient-specific dynamic slings for the treatment of SUI. These slings achieve up to 5% actuation within 90 s, while keeping the temperature of the surrounding environment physiologically safe. Further in vivo evaluation of the dynamic sling is currently underway. Source of Funding: This work was supported by the National Institute of Biomedical Imaging And Bioengineering of the National Institutes of Health under Award Number R21EB028547 © 2021 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 206Issue Supplement 3September 2021Page: e158-e158 Advertisement Copyright & Permissions© 2021 by American Urological Association Education and Research, Inc.MetricsAuthor Information Seelay Tasmim More articles by this author Philippe Zimmern More articles by this author Taylor Ware More articles by this author Expand All Advertisement Loading ...